NURS-6630 Week 1 discussion – Ion Channels and G Proteins
Ion Channels and G Proteins
This Discussion will allow you the opportunity to engage with your peers to explore the difference between ion channels and G proteins. You will be able to apply this understanding to a specific patient question. Additionally, please reply to your peers with additional information and sources to either support or challenge responses.
Resources
Be sure to review the Learning Resources before completing this activity.
Click the weekly resources link to access the resources.
WEEKLY RESOURCES
To prepare:
Review the Required Learning Resources.
Consider the difference between ion channels and G proteins.
By Day 3 of Week 1
Post
a response answering the following:
Explain the difference between ion channels and G proteins as they relate to signal transduction and targets of medications.
How would you answer the following patient question:
My grandmother has a mental illness. I have the same genes as her. Will I also get the same mental illness?
Note:
Your response needs to be supported and validated by three (3) scholarly peer-reviewed resources located
outside
of your course Learning Resources.
Upload a copy of your discussion writing to the draft Turnitin for plagiarism check. Your faculty holds the academic freedom to not accept your work and grade at a zero if your work is not uploaded as a draft submission to Turnitin as instructed.
Read
a selection of your colleagues’ posts.
By Day 6 of Week 1
You are required to participate in the Discussion on at least 3 different days (a different day for main post and each response). It is important to adhere to the weekly time frame to allow others ample time to respond to your posting.
Read
a selection of your colleagues’ posts
. Respond
to
at least two
of your colleagues on
2 different days
by supporting or expanding on their explanation, as well as how they have described their response to the patient.
Peer responses should include at least two (2) supporting scholarly, peer-reviewed references
outside
of the provided Learning Resources. Your responses should also include additional resources to either support or refute the responses and should demonstrate critical thinking.
Note:
Be sure you work to share additional perspectives on the details described by your colleague. Responses of “I agree” or “good point” will result in lower score grading.
NURS-6630 Week 1 discussion – Ion Channels and G Proteins
Main post
Cellular communication and function depend heavily on signal transduction, the process by which a cell reacts to outside stimuli. Ion channels and G proteins are two important participants in this process and important candidates for pharmaceutical treatments. These molecules differ greatly in their structure, function, and how drugs target them, even though they play similar functions in signal transduction.
Ion Channels: Overview and Purpose
Ion channels, which permit certain ions like sodium (Na⁺), potassium (K⁺), calcium (Ca²⁺), or chloride (Cl⁻) to flow through, are pore-forming proteins embedded in the cell membrane. These channels respond to various stimuli and can be voltage-gated, ligand-gated, or mechanically gated. Ion channels are essential for preserving the membrane potential at rest, producing action potentials, and controlling ion concentrations inside cells. For instance, potential action initiation and propagation in neurons depend on voltage-gated sodium channels. Ion channel-targeting medications frequently work by varying the opening or closure of the channels. One such would be local anesthetics such as lidocaine, which block voltage-gated sodium channels to stop nerve impulses from propagating and relieve pain (Hille, 2001).
G Proteins: Composition and Role
G proteins, sometimes referred to as guanine nucleotide-binding proteins, are molecular switches that transmit signals from intracellular signaling pathways to cell surface receptors called G protein-coupled receptors (GPCRs). When a ligand attaches itself to a GPCR, the receptor encourages the G protein’s alpha subunit to swap GDP for GTP, activating the corresponding G protein. G protein can affect several intracellular effectors like phospholipase C or adenylate cyclase, which can result in the production of second messengers like IP₃ or cAMP. G proteins are important targets for drug development because they are involved in many physiological processes. For example, beta-blockers, which are frequently used to treat hypertension, lower blood pressure and heart rate by blocking the function of G proteins connected to beta-adrenergic receptors (Rang, Dale, Ritter, & Flower, 2016).
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G Proteins vs. Ion Channels for Drug Targeting
Ion channels and G proteins are equally essential for signal transduction, but the way that drugs target them is different. Drugs can directly target ion channels to either block or increase ion flow, which can modulate electrical activity or reactions within cells. Drugs that target G proteins, on the other hand, usually work on the receptors (GPCRs) that either activate these proteins or have an impact on the signaling cascades that they regulate downstream. The possibility to create medications that selectively target G protein signaling pathways while having no effect on other pathways mediated by the same receptor is one area of study in pharmacology. As evidenced by the creation of biased agonists, which specifically activate particular G protein pathways, this specificity may result in more potent therapies with fewer adverse effects (Wootten, Christopoulos, & Sexton, 2013).
G proteins and ion channels are both essential elements of signal transduction, although they function differently and are targeted differently by medications. Comprehending these variations is crucial for the advancement of more accurate and efficacious pharmaceutical interventions.
How would you answer the following patient question:
My grandmother has a mental illness. I have the same genes as her. Will I also get the same mental illness?
I would advise the patient that genetic predisposition can increase the risk of developing certain mental illnesses, but it does not guarantee that this patient will get the same mental illness.
References
Hille, B. (2001).
Ion channels of excitable membranes
(3rd ed.). Sinauer Associates.
Rang, H. P., Dale, M. M., Ritter, J. M., & Flower, R. J. (2016).
Rang and Dale’s Pharmacology
(8th ed.). Elsevier.
Wootten, D., Christopoulos, A., & Sexton, P. M. (2013). Emerging paradigms in GPCR allostery: implications for drug discovery.
Nature Reviews Drug Discovery, 12
(8), 630-644.
https://doi.org/10.1038/nrd4052
Links to an external site.
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Destin Mcneill
Aug 30, 2024 12:36am
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Last reply Sep 1, 2024 9:53pm
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MAIN POST
Ion channels are proteins located in the cell membranes of all living organisms. Their job is to create pathways to allow specific ions like sodium, potassium, calcium, and chloride to pass through so physiological processes can take place in the living organisms it’s residing in. The ion channels open and close creating an immediate responses like cell excitability, muscle contractions, and neurotransmitter release. According to Cen et al., (2024) Lysosomes are highly dynamic organelles that maintain cellular homeostasis and regulate fundamental cellular processes by integrating multiple metabolic pathways. Lysosomal ion channels such as TRPML1-3, TPC1/2, ClC6/7, CLN7, and TMEM175 mediate the flux of Ca2+, Cl−, Na+ , H+ , and K+ across lysosomal membranes in response to osmotic stimulus, nutrient-dependent signals, and cellular stresses. These ion channels serve as the crucial transducers of cell signals and are essential for the regulation of lysosomal biogenesis, motility, membrane contact site formation, and lysosomal homeostasis. In terms of pathophysiology, genetic variations in these channel genes have been associated with the development of lysosomal storage diseases, neurodegenerative diseases, inflammation, and cancer. This review aims to discuss the current understanding of the role of these ion channels in the central nervous system and to assess their potential as drug targets. Some target medications of ion channels are calcium channel blockers, sodium channel blockers, and potassium channel openers.
G Proteins, or guanine nucleotide-binding proteins are molecular switches located intracellular that transmit signals outside the cell to inside the cell. They play a very essential role in intracellular signaling pathways, and are involved in many cellular processes like gene expression, cell growth, and metabolism changes. One of their main functions is their activation and inactivation cycle. Torres-Rodriguez (2024) Heterotrimeric G-proteins are universal signaling conduits in all eukaryotic groups, ranging from yeast and humans to algae and vascular plants. They regulate a variety of cellular processes involving millisecond-level responses, such as perception of light or neurotransmission in humans, to slower lifetime-level developmental aspects, such as body plan and architecture in plants. In all organisms, the core G-protein complex consists of one subunit each of the α, β, and γ proteins and exists in bimodal active
versus
inactive states. The transition between the active and inactive states is driven by the nucleotide-bound form of the Gα subunit. In the resting state, Gα is GDP-bound and associated with the Gβγ dimer. Signaling is initiated when the bound GDP is exchanged for GTP on Gα, which results in conformational changes that dissociate the heterotrimeric complex into Gα·GTP and Gβγ. Both entities can interact with downstream effectors to transduce the signal. Ion channels involve direct regulation signal transduction across the cell membrane. While G Proteins involve indirect signal transduction activation of signal pathways.
How I’d respond to the question would there is a possibility. But, not a definite yes or no. Because it depends on what the mental illness is, and what specific genes are involved, and/or inherited. Having the same genes as the grandma may increase the risk of developing a similar mental illness. But, it’s not a definite certainty. Mental illnesses are caused by multiple gene interactions. A Single gene that has no other genes to interact with will definitely not cause mental illnesses because it needs other genes to communicate with to even develop a mental illness. Being the genes are not from the person’s immediate family, the parents, and from I guess a third party relative. Complex gene interactions, along with environmental and lifestyle factors influence mental illnesses. According to Hoy et al., (2023) In recent years, molecular genetic research has shifted its focus from candidate gene studies to genome-wide approaches in aiming to identify the genetic architecture underlying complex traits and disorders. For example, genome-wide association studies (GWASs) compare the frequencies of a large number (typically 500k-1 M) of common variants across the genome (e.g., single-nucleotide polymorphisms or SNPs) between cases of a given phenotype (e.g., depressed patients) and controls. Summary statistics from these studies can then be used to calculate polygenic scores (PGSs) in independent samples, providing a single quantitative metric of genetic risk for a particular trait or disorder based on the aggregate effects of genetic variants found to be associated with that phenotype through the relevant GWAS. These approaches capture polygenetic influences on psychiatric phenotypes (i.e., the contribution of multiple genetic variants to a given disorder) and have consistently demonstrated evidence of widespread pleiotropy across different forms of mental illness. That is, genetic variants influencing the expression of psychopathology are largely shared across putatively distinct diagnostic categories
Cen, J., Hu, N., Shen, J., Gao, Y., & Lu, H. (2024). Pathological Functions of Lysosomal Ion Channels in the Central Nervous System.
International Journal of Molecular Sciences
,
25
(12), 6565. https://doi.org/10.3390/ijms25126565
Hoy, N., Lynch, S. J., Waszczuk, M. A., Reppermund, S., & Mewton, L. (2023). Transdiagnostic biomarkers of mental illness across the lifespan: A systematic review examining the genetic and neural correlates of latent transdiagnostic dimensions of psychopathology in the general population.
Neuroscience and Biobehavioral Reviews
,
155
. https://doi.org/10.1016/j.neubiorev.2023.105431
Torres-Rodriguez, M. D., Lee, S. G., Roy Choudhury, S., Paul, R., Selvam, B., Shukla, D., Jez, J. M., & Pandey, S. (2024). Structure-function analysis of plant G-protein regulatory mechanisms identifies key Gα-RGS protein interactions.
Journal of Biological Chemistry
,
300
(5). https://doi.org/10.1016/j.jbc.2024.107252
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Cheryl Athurine Spence
Aug 29, 2024 10:21pm
|
Last reply Aug 31, 2024 8:16pm
Reply from Cheryl Athurine Spence
Response to post discussion 2
The Difference Between Ion Channels and G Proteins
Hello, Sharon. I liked your post on Ion channels and G protein. They are both essential aspects of cellular transduction, and although they react to different mechanisms, medications can target ions differently. Ion channels are protein structures that form pores into cell membranes, enabling specific ions to go in or out. According to Raines et al. (2022), ion channels are relatively long macromolecules and made up of subunits extending the cell membrane. Ion channels are classified based on the ion that they allow to pass, such as sodium (Na
+
), potassium (K
+
), calcium (Ca
2+
), or chloride (Cl
−
) (Raines et al., 2022). Whenever they are active, they directly alter the cell’s electrical potential. Voltage changes, ligands, or mechanical forces trigger the channels. Medications that target ion channels tend to operate either through blocking or modulating their activity. According to Hutchings et al. (2019), ion channel proteins transport ions across cell membranes and play critical roles in various physiological and pathophysiological processes. Examples of medications targeting ion channels include local anesthetics, which block sodium channels, and benzodiazepines, which trigger the activity of GABA receptor chloride channels.
On the other hand, G proteins are intracellular signaling molecules that serve as molecular switches. These proteins are active when bound to GTP and inactive when the GTP becomes hydrolyzed to GDP. G proteins tend to be coupled with cell surface receptors called G protein-coupled receptors (GPCRs). In their study, Maggio et al. (2021) noted that G proteins are more characterized partners of GPCRs, are trimeric proteins that become activated when nucleotide GTP made up of α, β, and γ subunits with the α on one side and the β/γ subunits. When activated, G proteins activate cascades of intracellular events—the medications targeting the G protein work by activating or inhibiting GPCRs. An example of drugs targeting the G proteins are the beta-blockers that inhibit beta-adrenergic GPCRs and opioids that activate the opioid GPCRs.
The notable differences between ion channels and G proteins are based on their mechanisms and impacts. Ion channels directly impact cell excitability, with typically faster and shorter-term effects. On the other hand, G proteins initiate more complex signaling cascades that tend to have extensive and longer-lasting impacts. This simplifies the fact that medications targeting ion channels are likely to produce immediate effects. In contrast, those targeting proteins tend to have a more comprehensive, prolonged impact on cellular function.
Genetics and Mental Illness
To the patient having concerns about her mental health, given the family history, it is essential to understand the concerns as being genuine. With the grandmother having a mental illness, it increases the risk of mental health issues. Still, it is not a guarantee that the same mental condition will affect another family member. Mental health issues are complex and may be influenced by both genetic and environmental factors. According to Fabbri (2022), psychiatric disorders are complex diseases with genetic-environmental pathogenesis, where people are born with some level of genetic risk factors contributing to disease susceptibility while the environmental risk factors accumulate the susceptibility. When some threshold value has been reached, a person manifests an active episode of illness. While a family history of mental illness predisposes one to high susceptibility, whether the genes are expressed is also influenced by other factors such as life experiences, stress levels, and other environmental influences.
References
Fabbri, C. (2022). Genetics in psychiatry: Methods, clinical applications, and future perspectives.
Psychiatry and Clinical Neurosciences Reports
,
1
(2), e6. https://doi.org/10.1002/pcn5.6
Hutchings, C. J., Colussi, P., & Clark, T. G. (2019). Ion channels as therapeutic antibody targets. In
MAbs
(Vol. 11, No. 2, pp. 265-296). Taylor & Francis. https://doi.org/10.1080/19420862.2018.1548232
Maggio, R., Fasciani, I., Carli, M., Petragnano, F., Marampon, F., Rossi, M., & Scarselli, M. (2021). Integration and spatial organization of signaling by G protein-coupled receptor homo-and heterodimers.
Biomolecules
,
11
(12), 1828. https://doi.org/10.3390/biom11121828
Raines, R., McKnight, I., White, H., Legg, K., Lee, C., Li, W., … & Shim, J. W. (2022). Drug-targeted genomes: Mutability of ion channels and GPCRs.
Biomedicines
,
10
(3), 594. https://doi.org/10.3390/biomedicines10030594
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Maria Kasmir Magbuo
Aug 29, 2024 7:31pm
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Last reply Sep 1, 2024 9:55pm
Reply from Maria Kasmir Magbuo
Hi Class
Functional and structural characteristics are two distinct areas in which ion channels and G proteins are significantly different from one another. Ion channels are proteins that produces gaps in cell membranes (Dai, 2023). These tiny openings allow certain ions such as potassium, sodium, chloride or calcium to move inside or out of the cell. Electrical signals are produced as a result of the movement of ions, and these electrical signals are essential for a variety of physiological activities, including the transmission of nerve impulses, the contraction of muscles (Dai, 2023), and the rhythm of the heart. When it comes to G proteins, this type of protein is found inside of cells that functions as molecular switches. They are related to receptors that are found on the surface of cells, which are known as G protein-coupled receptors or GPCRs (Fasciani et al., 2022). A ligand, which can be a hormone or a neurotransmitter, acts as the trigger for activating a receptor, which in response activates the G protein. The G protein eventually comes into contact with various different intracellular signaling molecules or pathways (Mafi et al., 2022).
Ion channels and G proteins individually have their own unique function in the process of signal transduction. It is possible for ion channels to be opened or closed directly in response to signals, such as neurotransmitters or medicines, which results in a rapid change in the membrane potential and activity of the cell (Dai, 2023). For instance, in response to neurotransmitters, neurotransmitter-gated ion channels open, allowing ions to travel through the membrane rapidly and influence cellular activity. In contrast, G proteins initiate more complex and slower signaling cascades. Rather than directly affecting the membrane potential, G proteins have the ability to either activate or inhibit a variety of enzymes and second messenger systems, such as calcium release or cAMP, which in turn leads to an extensive variety of cellular responses (Rehman et al., 2023). Compared to the quick and immediate effects of ion channels, this variation enables G protein channels to provide amplification and modulation of the initial signal, rendering them more adaptable and highly developed.
Drugs can selectively affect ion channels and G proteins based on their distinct mechanisms of therapeutic action. Drugs that target ion channels are developed with the intention of rapidly changing the flow of ions across cell membranes. For instance, pain signals can be blocked by local anesthetics by blocking sodium channels, while seizure activity can be reduced by anti-epileptic medications by stabilizing ion channels (Hernandez & Richards, 2023). G protein-coupled receptor (GPCR) or G protein targeted medications, on the other hand, influence cellular signaling pathways that are more complex. The action of GPCRs can be influenced by several medications, including beta-blockers, antihistamines, beta-blockers, and some psychiatric medications, which results in various therapeutic effects (Fasciani et al., 2022). The differentiation demonstrates how drugs may selectively target ion channels to produce rapid effects or activate G protein pathways to achieve more complex regulatory effects.
When it comes to answering the patient’s question, my answer would be “There is some evidence suggesting mental disorders may have a hereditary component. Having a family history of mental illness is a risk factor, but it does not mean the individual will also have the disorder. There can be an intricate correlation of genetic, environmental, and lifestyle variables in the development of mental illness (National Institutes of Health, 2024). Even while you and your grandmother share similar biological traits, this does not necessarily guarantee that you will acquire the same disorder as her. Other aspects, such as the environment around you, the experiences you’ve had in life, and the amount of stress you’re under, all play a vital impact (National Institutes of Health, 2024). Establishing a discussion with a healthcare provider who can provide you with more individualized guidance and assistance is a great option if you have concerns regarding your mental health.
References
Dai, G. (2023). Signaling by Ion Channels: Pathways, Dynamics and Channelopathies.
Missouri Medicine
. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10569386/
Fasciani, I., Carli, M., Petragnano, F., Colaianni, F., Aloisi, G., Maggio, R., Scarselli, M., & Rossi, M. (2022). GPCRs in intracellular compartments: New targets for drug discovery.
Biomolecules
,
12
(10), 1343. https://doi.org/10.3390/biom12101343
Hernandez, C. M., & Richards, J. R. (2023). Physiology, Sodium Channels.
StatPearls [Internet]
. https://www.ncbi.nlm.nih.gov/books/NBK545257/
Mafi, A., Kim, S., & Goddard, W. A. (2022). The mechanism for ligand activation of the GPCR–G protein complex.
Proceedings of the National Academy of Sciences
,
119
(18). https://doi.org/10.1073/pnas.2110085119
National Institutes of Health (NIH). (2024).
Looking at my genes: What can they tell me about my mental health?
National Institute of Mental Health (NIMH). https://www.nimh.nih.gov/health/publications/looking-at-my-genes
Rehman, S., Rahimi, N., & Dimri, M. (2023). Biochemistry, G Protein Coupled Receptors.
StatPearls [Internet]
. https://www.ncbi.nlm.nih.gov/books/NBK518966/
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Kim White
Aug 28, 2024 10:39pm
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Last reply Sep 1, 2024 9:58pm
Reply from Kim White
Ion channels and G proteins play crucial roles in signal transduction, but they function differently and are targeted differently by medications. Ion channels are proteins that form pores in cell membranes, allowing specific ions (like sodium, potassium, or calcium) to pass through. This ion movement generates electrical signals, which are vital for processes like muscle contraction, neurotransmission, and heartbeat regulation. Medications that target ion channels often aim to modify these electrical signals. For instance, some antiepileptic drugs work by stabilizing ion channels to prevent abnormal electrical activity in the brain.
G proteins, on the other hand, are involved in a more complex signaling pathway. They act as molecular switches inside cells, transmitting signals from various receptors on the cell surface to internal cellular mechanisms. When a signaling molecule (like a hormone or neurotransmitter) binds to a receptor on the cell surface, it activates a G protein. This G protein then triggers various downstream effects, such as enzyme activity or gene expression changes. Many medications, including certain antipsychotics and antihypertensives, target G protein-coupled receptors (GPCRs) to modulate these pathways.
Regarding the patient asking the question about mental illness and genetics, it’s important to clarify that while genetics play a role in the risk for mental illness, having the same genes as a family member with a mental illness does not guarantee that you will develop the same condition. A combination of genetic, environmental, and lifestyle factors influences mental illnesses. For example, someone might inherit a genetic predisposition for a mental illness but never develop it because they do not encounter the same environmental triggers or stresses. It is also possible to take preventive steps, such as maintaining a healthy lifestyle and seeking early intervention if symptoms arise, to reduce the risk of developing mental illness. This can be a complicated but important thing to discuss with individuals as they worry about moving forward and having their own children.
References
American Psychiatric Association. (2020).
The role of genetics in mental illness
. Retrieved from
https://www.psychiatry.org
Links to an external site.
Kandel, E. R., Schwartz, J. H., & Jessell, T. M. (2021).
Principles of neural science
(6th ed.). McGraw-Hill Education.
Swanson, L. W. (2018).
Brain architecture: Understanding the basic plan
(2nd ed.). Oxford University Press.
G proteins and ion channels are both crucial components of signal transduction pathways, but they serve different roles and mechanisms in cellular communication and pharmacological targeting.
G Proteins
G proteins, or guanine nucleotide-binding proteins, act as molecular switches in signal transduction. They are typically associated with G protein-coupled receptors (GPCRs), which are membrane proteins that detect extracellular signals such as hormones and neurotransmitters (Ahmad & Dalziel, 2020). Upon ligand binding, GPCRs undergo a conformational change that activates the associated G protein, leading to the exchange of GDP for GTP on the alpha subunit of the G protein. This activation causes the G protein to dissociate into its active components: the alpha subunit (now bound to GTP) and the beta-gamma dimer. These components can then interact with various downstream effectors, such as enzymes that produce second messengers (e.g., cyclic AMP) or ion channels, thereby propagating the signal within the cell.
G proteins are significant targets for medications, as they regulate numerous physiological processes. Approximately 34% of all FDA-approved drugs target GPCRs, highlighting their importance in pharmacology (Liu et al., 2021). Drugs can either activate or inhibit GPCRs, leading to therapeutic effects in conditions such as hypertension, depression, and cancer.
Ion Channels
Ion channels, on the other hand, are integral membrane proteins that allow specific ions to flow across the cell membrane, thereby altering the membrane potential and facilitating rapid cellular responses. They can be ligand-gated or voltage-gated, with ligand-gated ion channels opening in response to the binding of a neurotransmitter or other signaling molecule (Alexander et al., 2023). This quick change in ion permeability is crucial for processes like neurotransmission and muscle contraction.
While ion channels can be directly targeted by drugs (e.g., calcium channel blockers for hypertension), they can also be indirectly influenced by G proteins. For instance, activated G proteins can modulate the activity of certain ion channels, enhancing or inhibiting their function as part of a broader signaling cascade. This interplay between G proteins and ion channels exemplifies the complexity of signal transduction pathways and highlights potential therapeutic targets for drug development.
How would you answer the following patient question:
My grandmother has a mental illness. I have the same genes as her. Will I also get the same mental illness?
While you and your grandmother may share the same genes, this does not mean you will necessarily develop the same mental illness. Mental health conditions are complex and result from a mix of genetic and environmental influences. Your unique experiences, lifestyle choices, and overall environment can greatly impact your mental health. It’s important to prioritize your well-being and consider factors beyond genetics that contribute to mental health. If you have concerns, discussing them with a healthcare professional can provide valuable insights and support.
References
Ahmad, R., & Dalziel, J. E. (2020). G protein-coupled receptors in taste physiology and pharmacology.
Frontiers in pharmacology
,
11
, 587664.
Alexander, S. P., Mathie, A. A., Peters, J. A., Veale, E. L., Striessnig, J., Kelly, E., … & Zhu, M. (2023). The concise guide to PHARMACOLOGY 2023/24: Ion channels.
British Journal of Pharmacology
,
180
, S145-S222.
Liu, N., Wang, Y., Li, T., & Feng, X. (2021). G-protein coupled receptors (GPCRs): signaling pathways, characterization, and functions in insect physiology and toxicology.
International Journal of Molecular Sciences
,
22
(10), 5260.
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Alexis Carson
Aug 28, 2024 10:04pm
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Last reply Sep 1, 2024 11:56am
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Week One Discussion Post Two
2) My grandmother has a mental illness. I have the same genes as her. Will I also get the same mental illness?
Genetics and mental illness are an interesting but complex topic. Although having a close family member with a mental illness could increase the chances of developing the same illness, it’s not likely that you will develop the same condition.
There are some factors to consider.
Genetic Factors
Heritability:
Scientists have discovered evidence that many of the same genes have underlying distinct disorders, such as schizophrenia and autism, and changes in brain decision-making capacity could be involved in many of these illnesses. Genetic involvement in mental illness is seen through increased rates of disorders in first-degree family members who are diagnosed with disorders. Parents who are diagnosed with schizophrenia, bipolar disorders, and major depressive disorders, who have children, may have an increased risk of developing these illnesses but they may also develop other mental health disorders. Many factors contribute to the risk, but science has suggested that genetics carry the highest risk (Baselmans, et al, 2021).
Polygenic Nature:
Mental illness is often influenced by many genes rather than just one gene, hence polygenic. There are
polygenic links seen in mental illnesses causing social behavior changes seen in adolescent development up to adulthood. Mental illness is polygenic but it’s unclear if mental illness is caused by genetics (Schlag, et al, 2022).
Gene-Environment Interaction and Life Experiences:
Gene-by-environment interactions have shown that mental illness can be caused by environmental factors such as stress, trauma, lifestyle, and many other environmental factors. Combined with genetics and environmental factors, the interaction with genetic vulnerability is a risk of developing a psychiatric disorder even among individuals without a genetic predisposition. These can include drugs, and childhood trauma like being placed in a bad foster home, which can cause major polygenic depression, and even schizophrenia (Assary, et al, 2020).
Summary
Many risk factors can cause mental illness. You may have a higher risk of
developing a mental illness being
that your grandmother was diagnosed with a mental illness, it’s not guaranteed you will develop a disorder. As mentioned, environmental factors and genetics play a major part in the development of a psychiatric disorder. If you are worried about developing a mental illness, it is important to speak with your medical provider so they can help you maintain a healthy lifestyle and help you identify early signs and symptoms of mental illness, so you can manage any possible risks effectively.
Resources
Assary, E., Vincent, J., Machlitt-Northen, S., Keers, R., & Pluess, M. (2020). The role of gene-environment interaction in mental health and susceptibility to the development of psychiatric disorders.
Beyond Our Genes: Pathophysiology of Gene and Environment Interaction and Epigenetic Inheritance
, 117-138.
Baselmans, B. M., Yengo, L., van Rheenen, W., & Wray, N. R. (2021). Risk in relatives, heritability, SNP-based heritability, and genetic correlations in psychiatric disorders: a review.
Biological Psychiatry
,
89
(1), 11-19.
Schlag, F., Allegrini, A. G., Buitelaar, J., Verhoef, E., van Donkelaar, M., Plomin, R., … & St Pourcain, B. (2022). Polygenic risk for mental disorder reveals distinct association profiles across social behaviour in the general population.
Molecular psychiatry
,
27
(3), 1588-1598.
Week One Discussion Post One
Explain the difference between ion channels and G proteins as they relate to signal transduction and targets of medications.
Ion channels and G proteins are two distinctive types of proteins that play an essential role in cellular signal transduction.
Ion channels produce fast signaling conduction proteins that assist the movement of ions like sodium, potassium, calcium, and chloride across the cell membrane. They can open and close in response to a signaling molecule like growth hormones, binding to it, which can change the flow across the membrane (Hille, 2022).
They are essential for generating electrical signals within cells and are involved in various physiological processes, including muscle contraction, nerve communication, and hormone production. Ion channels can be activated or respond rapidly to specific molecules such as neurotransmitters or hormones (Sakmann, 2022).
As drug targets, ion channels are frequently targeted by certain medications. For instance, drugs that block specific ion channels can be used as an anesthetic or antiepileptics, by interrupting or stopping the communication of electrical signals in the nervous system. Also, medications that modify ion channel movement can be used to regulate blood pressure and treat cardiac arrhythmias (Giffin, Khan, Basu, & Smith, 2020)
G proteins, like the ion channel, are also drug targets. G proteins are intracellular signaling proteins that connect cell surface receptors to target molecules within the cell. When a signaling molecule, such as a hormone or neurotransmitter, which are messengers that bring signals from outside the cells, binds to a cell surface receptor, it activates a specific G protein, G protein-coupled receptors (GPCR) (Yang et al., 2021).
Most body tissues contain G protein-coupled receptors. GPCRs are seen in many conditions such as diabetes, certain cancers, and cardiovascular diseases. By modifying signaling pathways, drugs can activate or stop specific G protein-coupled receptors (GPCRs). For example, Beta-Blockers work by preventing GPCRs from moving into cardiac cells, which causes the heart rate to decrease allowing the blood pressure to decrease (Davies & Tomas, 2023).
Resources
1) Davies, A., & Tomas, A. (2023). Appreciating the potential for GPCR crosstalk with ion channels.
Progress in Molecular Biology and Translational Science
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195
, 101-120.
2) Griffin, M., Khan, R., Basu, S., & Smith, S. (2020). Ion channels as therapeutic targets in high grade gliomas.
Cancers, 12
(10), 3068.
3) Hille, B. (2022). Ionic channels in nerve membranes, 50 years on.
Progress in biophysics and molecular biology
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169
, 12-20.
4) Sakmann, B. (2022). Sparks in the Brain: The Story of Ion Channels and Nerve Cells.
Front. Young Minds
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10
, 858193.
5) Yang, D., Zhou, Q., Labroska, V., Qin, S., Darbalaei, S., Wu, Y., Yuliantie, E., Xie, L., Tao, H., Cheng, J. and Liu, Q., … & Wang, M. W. (2021). G protein-coupled receptors: structure-and function-based drug discovery.
Signal transduction and targeted therapy, 6(1), 7.
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Negatu Engdaw Ahmed
Aug 28, 2024 10:02pm
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Last reply Sep 1, 2024 10:06pm
Reply from Negatu Engdaw Ahmed
NURS 6630 week I discussion.
The objective of this week’s discussion assignment is to discern the distinction between ion channels and G proteins in terms of their involvement in signal transduction and as targets of pharmaceuticals. As discussed below, ion channels and G proteins are essential elements in biological signaling networks, despite their distinct functions and drug targets.
Ion Channels
Ion channels are specialized membrane proteins that are responsible for creating holes or channels across the cell membrane. These channels enable certain ions to enter or leave the cell.
They are necessary for many physiological functions and serve an important role in maintaining cellular homeostasis and communication. In 2018, New Media gathered this data. There are approximately 400 ion channel genes in the human genome, which fall into three superfamilies: voltage-gated, ligand-gated, and mechano-sensitive.
Their function in signal transduction
:
Ion channels are important for almost all physiological processes, such as heartbeat control, muscle contraction, and neuronal transmission. Based on New Media 2018 information. Ion channels have a crucial role in nearly all physiological processes, including the regulation of heartbeat, muscular contraction, and neuronal transmission. Ion channels are protein structures that form pores in the cell membrane, facilitating the specific transport of particular ions (such as Na+, K+, Ca2+, or Cl-) across the cell membrane. When these channels become activated or deactivated, they modify the distribution of ions within the cell. This can quickly modify the cell’s membrane potential and have an impact on many physiological reactions, such as muscle contraction, release of neurotransmitters, and electrical communication in neurons. For example, the opening of sodium channels can lead to neuron depolarization, triggering an action potential. When these channels become activated or deactivated, they modify the distribution of ions within the cell, leading to a quick shift in the cell’s membrane potential (Martinac 2012).
The targets of medication
Medications frequently aim to modify the activity of ion channels. For example, the information from Cleveland Clinic (2022) explains the following medication targets.
i) Calcium channel blockers, such as verapamil and amlodipine, inhibit calcium entry into cardiac and smooth muscle cells to treat hypertension.
ii) Sodium channel blockers, like lidocaine, serve as both local anesthetics and antiarrhythmic medications.
iii) By delaying the repolarization process, potassium channel blockers like sotalol treat arrhythmias. (Cleveland Clinic, 2022)
B)
G-proteins
A) Their function in signal transduction:
The following information about G protein comes from Alberts, B. (1970).
G proteins are intracellular signaling molecules that transmit signals from receptors on the cell surface to different intracellular effectors. The binding of ligands to G proteins triggers the activation of related G proteins through the substitution of GTP for GDP. Upon activation, the alpha and beta subunits of the G protein separate and participate in signal transduction within the cell.
It directly influences ion channels or modulates enzymes such as adenylate cyclase and phospholipase C, which in turn govern several cellular functions (Alberts, B. (1970).
Targets of medications:
Medications that affect G protein-coupled receptors (GPCRs) have an indirect impact on G proteins, Sriram & Insel (2018). For example:
i) Beta-blockers, such as propranolol, target beta-adrenergic receptors, which are G protein-coupled receptors (GPCRs). Doctors prescribe them to treat hypertension and heart problems.
ii) Opioids, such as morphine, exert their effects by binding to opioid receptors, which are a type of G protein-coupled receptors (GPCRs). This interaction influences the experience of pain and mood.
iii) Antihistamines, such as diphenhydramine, specifically act on histamine receptors, which are G protein-coupled receptors (GPCRs) that have a role in allergic reactions.
In conclusion, while both ion channels and G proteins are crucial for signal transduction, different classes of drugs target them and have unique mechanisms of action.
Regarding the lady’s inquiry, it should be noted that genetics plays a role in the likelihood of developing mental diseases; however, sharing the same genes as her grandmother does not guarantee that she will develop the same mental illness. However, mental health issues are not solely hereditary; lifestyle, environmental circumstances, and other variables can significantly influence the onset and progression of mental health issues (Würmann, 2021). It is also crucial to highlight that mental diseases are complicated and often caused by the interplay of numerous genes rather than a single gene. Because of this intricacy, even close relatives may have diverse mental health experiences. Supportive relationships, a healthy lifestyle, and stress management may all help to reduce the risk, even if there is a genetic propensity for differing mental health outcomes (Imbrici et al. (2016).
References:
Alberts, B. (1970, January 1).
Signaling through G-protein-linked cell-surface receptors
. Molecular Biology of the Cell. 4th edition. https://www.ncbi.nlm.nih.gov/books/NBK26912/
Cleveland Clinic. (2022, January 7).
Calcium Channel Blockers: Types, Uses and Side Effects
. Cleveland Clinic. https://my.clevelandclinic.org/health/treatments/22316-calcium-channel-blockers
Imbrici, P., Liantonio, A., Camerino, G. M., De Bellis, M., Camerino, C., Mele, A., Giustino, A., Pierno, S., De Luca, A., Tricarico, D., Desaphy, J., & Conte, D. (2016). Therapeutic approaches to genetic ion channelopathies and perspectives in drug discovery.
Frontiers in Pharmacology
,
7
.
https://doi.org/10.3389/fphar.2016.00121
Links to an external site.
)
Martinac, B. (2012). Mechanosensitive ion channels.
Channels
,
6
(4), 211–213. https://doi.org/10.4161/chan.22047
News-Medical. “Importance of Ion Channels in the Body.” News-Medical.net, 26 Oct. 2018, www.news-medical.net/health/Importance-of-Ion-Channels-in-the-Body.aspx.
Sriram, Krishna, and Paul A. Insel. “G Protein-Coupled Receptors as Targets for Approved Drugs: How Many Targets and How Many Drugs?”
Molecular Pharmacology
, vol. 93, no. 4, 3 Jan. 2018, pp. 251–258, https://doi.org/10.1124/mol.117.111062.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4590096/
Würmann, Isaac. “My Mother and I Have the Same Mental Health Disorders. But Is It Genetic? | Broadview Magazine.” Broadview Magazine, 5 Oct. 2021, broadview.org/mental-illness-family-genetics/. Accessed 29 Aug. 2024
NURSE 6630 week 1 discussion-2.docx
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Cheryl Athurine Spence
Aug 28, 2024 9:40pm
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Reply from Cheryl Athurine Spence
The Difference between Ion Channels and G Proteins in Signal Transduction and Medication Targets
Ion channels and G proteins are cellular signaling pathways involved in various forms of cellular transduction. For instance, an ion channel is any inherent protein part of the cell membrane that enables the selective transport of ions essential in generating electrical signals in cells. Ion channels are selective for Na
+
, K
+
, Ca
2+
, or Cl
–
(Duncan et al., 2020). These channels transport ions and play significant roles in physiological activities such as nerve impulse conduction, muscle contraction, and osmoregulation at the cellular level. Ion channels are categorized as voltage-dependent channels, which can open depending on the voltage variation of the cell membrane, and the ligand-dependent channel, which opens when in contact with certain substances (Langenhan, 2020).
For example, in neurons, when a neurotransmitter engages with its receptor, it can potentiate the ion channels to open, leading to the flow of sodium ions into the neuron, creating an action potential. This process is faster because of the direct nature of the ion channel current. It suits them when one requires a quick signal, such as muscle contraction and nerve impulses. Thus, the drugs that act on these channels can regulate cellular excitability, such as anti-arrhythmic medicines, which can interfere with ion channels and restore the regular heartbeat.
G proteins interact with several types of cell surface receptors collectively known as G protein-coupled receptors (GPCRs). After binding the ligand to a GPCR, the receptor causes the activation of the G protein through the replacement of GDP by GTP. Subsequently, the G proteins get activated, and they, in turn, get involved with other effectors like enzymes or ion channels to relay the signal (Langenhan, 2020). This mechanism makes the response longer and more diverse than the effect that occurs with the participation of ion channels. G proteins can regulate so many body activities and thereby affect several functions of the body (Duncan et al., 2020). Medications targeting G proteins or GPCRs can treat a variety of conditions, such as antipsychotic medications, to control the symptoms of patients dealing with mental disorders.
It is important to note that some mental disorders are inherited. Similar genes are associated with the family tree, such as the grandmother, which can imply the existence of a genetic tendency toward mental health conditions. However, the problem provides a narrow concept of thinking. For instance, there can be other causes of mental conditions, such as environmental factors and coping styles of an individual (Zhang et al., 2023).
With the genetic makeup and cultural differences, family members are prone to have the same similarities in developing the same disorders. However, there can be a thought that one may get a hint of what kind of disorder they are prone to by family history; this does not always mean one will develop the disorder. A person’s genes may make them more likely to have mental illness. Still, the environment and the individual’s psychological conditions will dictate whether the person gets the disease. It is essential to explain the necessity of people turning to more of healthier coping strategies, asking for help whenever desired from specialists, and learning how to identify symptoms of mental health before becoming diagnosed with a mental illness.
References
Duncan, A. L., Song, W., & Sansom, M. S. (2020). Lipid-dependent regulation of ion channels and G protein-coupled receptors: insights from structures and simulations.
Annual review of pharmacology and toxicology
,
60
(1), 31–50.
Langenhan, T. (2020). Adhesion G protein-coupled receptors—Candidate metabotropic mechanosensory and novel drug targets.
Basic & clinical pharmacology & toxicology
,
126
, 5–16.
Zhang, M., Ma, Y., Ye, X., Zhang, N., Pan, L., & Wang, B. (2023). TRP (transient receptor potential) ion channel family: Structures, biological functions and therapeutic interventions for diseases.
Signal Transduction and Targeted Therapy
,
8
(1), 261.
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Sarah Rachael Tabor
Aug 28, 2024 9:18pm
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Last reply Sep 1, 2024 10:11pm
Reply from Sarah Rachael Tabor
Good afternoon class. I’m so grateful to be here and look forward to learning alongside you all. This first week was interesting for me because it’s been a while since I reviewed the specificity of the cell and the very minute and detailed things that have to occur for signals to be sent through neurons. It was humbling to review this information and to remember all of the intricate processes that have to happen for our brains to function the way they do.
Signal transduction includes all molecular events that take place between the arrival of a signaling molecule of the target cell and the response. Two pathways for this conduction to occur include the G-protein pathway and ion channel pathway. (Chandler, 2022). It’s all about signal transduction. That’s where the magic happens. Everything that we are able to do is through the adequate conduction of these signals.
The brain is approximated to have about 85 billion neurons! Incredible. Neurons are nerve cells which are the units that make up the nervous system. Neurons are made up of structures that receive messages, process these messages, transport messages and then ultimately pass on the messages. Dendrites are the portion of the neuron that receives signals from other neurons called neurotransmitters. Chemical changes that occur secondary to the reception of the neurotransmitters are processed in the Soma or the cell body. The Soma contains the nucleus and genetic material of the cell. The interpreted message is then sent to the Axon Hillock of the neuron, then it is sent to the Axon where it is now called the action potential. This portion of the neuron is enclosed in Myelin which is a protective characteristic which prevents the action potential from degrading. When the signal reaches the axon terminals there is potential for the signal to be sent to the next neuron if it was strong enough. (Nei psychopharm, 2022). That is, for the message to continue to pass through the cells of the nervous system.
G-proteins and ion channels are structures within the cell that are pathways or neurotransmitter receptors for ions to be passed through. (Alberts, Johnson, Lewis, et al., 2002). The messages that are sent through these potential pathways may be potentiated by things such as medications and hormones. (Neuroscientifically Challenged, July 2014).
For Ion channels, the neurotransmitters attach to the binding site causing it to open and then ions are able to send the action signal through the neuron. The neurotransmitter that attaches to the binding site is called the Ligand. After the Ligand is attached to the binding site the channel immediately opens. (Neuroscientifically Challenged, September 2014).
G-proteins have an activation neurotransmitter that must be received to activate the G protein to influence opening the channel for pathways. This G protein has the capability of opening more than it’s single pathway. This pathway also impacts other activity in the cell. These receptors act slower but may have a more widespread impact because of the potential influence on other activities in the cell. Both of these pathways are located at the site of the receptor neuron or the dendrite where signals are received.
There are some mental illnesses that have been thought of as “running in families” but little evidence has been found to ascertain whether there are definitive genetic determinants. Autism as an example is associated with signs such as early and rapid brain growth in infancy and childhood associated with atypical connectivity between different regions of the brain. Research suggests a strong genetic influence but environmental factors also have significant influence on this condition as well. (Neuroscientifically Challenged, 2021). When discussing genetics and the concern for being diagnosed with a mental illness based off of what happened with a person’s grandma one would have to look at the specific condition and take environmental factors into consideration as well.
So ultimately my response to this woman would be not to worry too much about developing her grandmother’s condition. I would discuss with her things to look for if she is deeply concerned but as long as she was not dealing with any of the particular symptoms of the particular condition, just encourage her to focus on the positive things in her life.
Sources
Alberts B, Johnson A, Lewis J, et al. Molecular Biology of the Cell. 4th edition. New York: Garland Science; 2002. Ion Channels and the Electrical Properties of Membranes. Available from: https://www.ncbi.nlm.nih.gov/books/NBK26910/
Chandler, R., PhD. (2022). Signal transduction.
Salem Press Encyclopedia of Health
.
NEI Psychopharm. (2022, March 14).
Classic synaptic neurotransmission
Links to an external site.
Links to an external site.
Links to an external site.
[Video]. YouTube.
Links to an external site.
Neuroscientifically Challenged. (2014, July 22).
2-Minute neuroscience: Synaptic transmission
Links to an external site.
Links to an external site.
Links to an external site.
[Video]. YouTube.
Links to an external site.
Neuroscientifically Challenged. (2014, Sept 26).
2-Minute neuroscience: Receptors & ligands
Links to an external site.
Links to an external site.
[Video]. YouTube. https://www.youtube.com/watch?v=NXOXZ-kaSVI
Neuroscientifically Challenged. (2021, Dec. 20).
2-Minute Neuroscience: Autism
.
2-Minute Neuroscience: Autism (youtube.com)
Links to an external site.
Accessed Aug. 28, 2024.
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Abosede Fakorede
Aug 28, 2024 8:07pm
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Last reply Sep 1, 2024 10:13pm
Reply from Abosede Fakorede
The difference between ion channels and G proteins as they relate to signal transduction and targets of medications
Ion channels and G proteins are proteins involved in signal transduction in cells thus associated with the mode of action and therapeutic effect of many drugs. The two proteins are involved in the transmission of signals across cell membranes and response to the signals. Although ion channels and G proteins are transmembrane proteins involved in signal transduction, the two work in different manners to cause a certain response. Ion channels are transmembrane proteins that ensure signal transduction by forming pores through which ions pass in and out of cells (Alexander et al., 2023). Ion channels allow specific ions across the cell membrane through the formation of specific pores for the specific ions. Ion channels directly transmit specific ions through the direct opening and closing of gated ion channels. For example, sodium ions use sodium ion channels to cause action potential. The pores directly open or close when certain molecules bind to receptors in the cell membrane, when electoral potential across the cell membrane changes, or when physical stress causes the pores or channels to mechanically open. Signal transduction involving ion channels is direct unlike signal transduction involving G proteins which is complex. Some medications such as calcium blockers work by targeting ion channels by causing direct opening or closing of ion channels (Alexander et al., 2023). Calcium channel blockers prevent calcium ions from entering into cells thus reducing muscle relaxation and contraction.
The major difference between G proteins and ion channels is that G proteins involve a complex signal transduction system while ion channels involve a simple or direct signal transduction process. G proteins indirectly cause signal transduction (Jiang et al., 2022). Two steps are involved in signal transduction when G proteins are involved. Signals must first bind to G-protein-coupled receptors (GPCRs) to activate the G protein. The G protein then interacts, activates, or inhibits various proteins or targets including enzymes and ion channels to cause cellular response (Ahmad & Dalziel, 2020). Cellular response involving G proteins includes changes in the activities of enzymes and expression of genes. Some medications work by targeting or influencing GPCRs and G proteins in cell membranes to cause the intended therapeutic effects. Beta-blockers and most antipsychotics for depression target the G proteins and GPCRs. G proteins mainly involve ligands where signals bind to receptors to cause signal transduction (Ahmad & Dalziel, 2020). Specific indirect neurotransmitters such as adrenaline that act on specific receptors are influenced to cause cellular response.
My grandmother has a mental illness. I have the same genes as her. Will I also get the same mental illness?
Since my grandmother is my relative, we share the same gene. However, having the same genes does not mean I will get the same mental diseases as my grandmother. Genetic predisposition or family history increases the risk of developing genetic conditions but does not guarantee the direct development of the conditions. An interplay or interaction of genetic factors, environmental factors such as temperature, and lifestyle factors are required for the development of mental health illnesses. One may have a family history of mental disorders but may not develop the mental disorders.
References
Ahmad, R., & Dalziel, J. E. (2020). G protein-coupled receptors in taste physiology and pharmacology.
Frontiers in pharmacology
,
11
, 587664.
Alexander, S. P., Mathie, A. A., Peters, J. A., Veale, E. L., Striessnig, J., Kelly, E., … & Zhu, M. (2023). The concise guide to PHARMACOLOGY 2023/24: Ion channels.
British Journal of Pharmacology
,
180
, S145-S222.
Duncan, A. L., Song, W., & Sansom, M. S. (2020). Lipid-dependent regulation of ion channels and G protein–coupled receptors: insights from structures and simulations.
Annual review of pharmacology and toxicology
,
60
(1), 31-50.
Jiang, H., Galtes, D., Wang, J., & Rockman, H. A. (2022). G protein-coupled receptor signaling: transducers and effectors.
American Journal of Physiology-Cell Physiology
,
323
(3), C731-C748.
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Ashli Cyriaano
Aug 28, 2024 6:34pm
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Last reply Sep 1, 2024 10:15pm
Reply from Ashli Cyriaano
Ion Channels and G Proteins
Ion channels and G proteins transmit signals in cells in different ways, determining how cells will respond to stimuli. Ion channels represent a class of proteins embedded in the cell membrane and create channels for certain ions. It is important for the shifting of the membrane potential in a very short time, which makes cellular responses to stimuli very fast (Bionet, 2021). For instance, voltage-gated sodium channels are integral components of neurons in transmitting action potentials. Ion channel-linked drugs, ranging from antiarrhythmic drugs to drugs used in the treatment of epilepsy, seek to block or modulate these channels to correct an electrochemical imbalance within the heart or nervous system.
On the other hand, G proteins are signal transducers that act as signaling molecules inside the cell that connect the GPCR at the cell membrane to intracellular effectors such as enzymes or ion channels. When a GPCR binds to its ligand, it promotes the exchange of GDP with GTP for the G protein to become activated. This activation then leads to the activation of other pathways or downstream signaling pathways (Rehman et al., 2023). Ion channels signal faster and transient responses, while G-proteins signal slower and sustained cellular responses. The G protein-directed drugs normally interact with the GPCR to alter physiological processes such as mood or blood pressure. For example, some of the drugs used in the treatment of depression work by interacting with GPCRs to alter concentrations of neurotransmitters and, thus, the feelings and moods of the patient.
Patient Question Response
In terms of family inheritance of mental disorders, yes, having a grandmother with such a disorder does put one at higher risk for similar disorders due to the general inheritance of certain genes. However, genetics alone cannot predict risks and is only one factor in various possibilities. Other causes of mental health disorders are framed within aspects of the environment, real-life decisions people make, and their life experiences as well. However, this does not mean that if one has inherited genes for a certain mental illness, then one is bound to develop that disorder (Andreassen et al., 2023). Research shows that even though certain genes make one vulnerable to developing certain mental health disorders, the overall vulnerability is a function of the genes and environment interface (Boyce et al., 2020). As a result, even though one has to be conscious of certain congenital abnormalities, one must also pay much attention to other factors of wellness and living with proper precautions to prevent possible mental health problems.
References
Andreassen, O. A., Hindley, G. F., Frei, O., & Smeland, O. B. (2023). New insights from the last decade of research in psychiatric genetics: discoveries, challenges and clinical implications.
World Psychiatry
,
22
(1), 4-24.
Bionet. (2021, March 8).
Ion channels
[Video]. YouTube.
https://www.youtube.com/watch?v=0p08-139
Links to an external site.
Boyce, W. T., Sokolowski, M. B., & Robinson, G. E. (2020). Genes and environments, development and time.
Proceedings of the National Academy of Sciences of the United States of America
,
117
(38), 23235–23241.
https://doi.org/10.1073/pnas.2016710117
Links to an external site.
Rehman, S., Rahimi, N., & Dimri, M. (2023, July 30).
Biochemistry, G protein coupled receptors
. StatPearls – NCBI Bookshelf.
https://www.ncbi.nlm.nih.gov/books/NBK518966/
Links to an external site.
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Tenikqua Fullwood-Maple
Aug 28, 2024 4:30pm
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Last reply Sep 1, 2024 10:19pm
Reply from Tenikqua Fullwood-Maple
Initial Post
Signal transduction
There are four very important transduction cascades that are in the brain, out of the four I will be discussing two of them. (Stahl, 2021) indicated that there are four most important signal transduction cascades in the brain, g-protein-linked systems, ion-channel-linked systems, hormone-linked systems and neurotrophins-linked systems. The two that will be discussed in this discussion are G-protein-linked systems and ion-channel-linked system. Each of these transduction cascades are initiated by a first messenger, such as g-protein and ion-channel. There are chemical messengers that are attached to each of the signal transduction cascades and are triggered by neurotransmitters. Once there is an activation of the first messenger there is a trickle-down effect, that then activates second, third, and fourth messenger. The signal transduction cascades ultimately pass its message from an extracellular first messenger to intracellular second messenger. In reference to the g-protein, its second messenger is a chemical as cAMP. In reference to ion-channel, its second messenger can be an ion and that ion can be a calcium ion. In reference to the g-protein, the third messenger protein kinase is activated from Camp. In reference to the ion-channel, the third messenger phosphatase is activated through the messenger calcium.
G-Protein
Psychotropic medication has an array of actions, by which they target specific molecular areas that potentially have an extensive effect on neurotransmitters. Psychotropic drugs can target five molecular sites. Out of the five one is g-protein, thirty percent of psychotropic medications target the g-protein. Twenty percent of psychotropic medications target the ion channels. The superfamily of seven transmembrane receptors is characterized by having seven highly conserved transmembrane alpha helices (Seyedabadi, Ghahremani, Albert, 2019). With g-protein being one of the larger membrane protein family, which contains seven transmembrane, allowing the nervous system to respond appropriately to external and internal stimuli. The unique ligand binding pockets formed by the seven transmembrane receptors regions allow the receptor to engage with various stimuli, including neurotransmitters, nucleotides, amines, peptides, cytokines, and hormones in the extracellular environment (Wong,
et al,
2023). Psychotropic medications interact at the neurotransmitter binding site that is located on the receptor. When this interaction occurs, it leads to modification of the receptors actions, resulting in mimicking, blocking, partially or fully, the function of the neurotransmitter. When psychotropic medication interacts at the g-protein, it alters molecular events further downstream of the g-protein. At the level of the g-protein-linked receptor, the g-protein have a sufficient action on psychiatric symptoms. Most psychotropic medications that are used in the clinical setting have an action on the g-protein, which results in a therapeutic manner or causes some side effects.
Ion Channels
Ion channels regulate calcium, sodium, chloride, and potassium, in reference to psychotropic medications. There are a number of psychotropic medications that act at the site of ion channels, resulting in modifications of the ion channel. The modifications that occur can alter the flow of ions throughout the channel but can also alter the downstream events. These downstream events can result in activation or inactivation of ion channels. Psychotropic medications that modify signal transduction from ionotropic receptors can have a major impact on a person that is displaying psychiatric symptoms. Several psychotropic medications that are used in clinical settings such as benzodiazepines, are known to act as the ionotropic receptor sites. The flow of ions is immediately changed at the ionotropic receptor, medications tend to have an immediate effect action, by which the drugs that are used for anxiety and sleep may have a rapid onset.
My grandmother has a mental illness. I have the same genes as her. Will I also get the same mental illness?
Mental illness is a serious illness and sometimes can be scary for family members of those who suffer with mental illness. Your question of concern is a good question. Many things are passed on from one generation to the next, by our genetic, but fortunately not all illness or diseases are passed through genetics. Although mental illness has a genetic component, which in saying it can run throughout families, but having a family as your grandmother that suffers with mental illness doesn’t automatically guarantee that you will suffer with the same mental illness. Most genetic variants don’t directly cause mental disorders (National Institute of Mental Health, 2024). There are some genetic components that can increase the risk of mental illness but doesn’t directly cause one to develop the mental illness. When taking care of a family member or surrounding yourself with a family member with mental illness, it is important you also take care of your mental health, because it can be a stressful and mentally draining situation when dealing with someone who suffers with a mental illness. However, if the sick person received care that was professional, adequate and of a high standard, the relatives’ stress and burden decreased (Kallquist & Salzmann-Erikson, 2022). There are ways to increase a healthier mental health, by decreasing or alleviating stress factors, healthy habits, and having a great support system. It is also important that you seek help or assistance if you feel that you may be suffering with signs or symptoms related to mental help, the best way to address mental illness is addressing and treating signs and symptoms early on.
Reference
Goldin, D. S. (2023).
Fast facts for psychopharmacology for nurse practitioners
. Springer
Publishing. Chapter 3, “The Brain and Nervous System” (pp. 28)
Kallquist, A. & Salzmann-Erikson, M. 2022. Journal of Child and Family studies. Springer
Publishing.
Experiences of Having a Parent with Serious Mental Illness: An Interpretive Meta-Synthesis of Qualitative Literature | Journal of Child and Family Studies (springer.com)
Links to an external site.
Seyedabadi, M., Ghahremani, M., & Albert, P. Biased signaling of G protein coupled receptors
(GPCRs): Molecular determinants of GPCR/transducer selectivity and therapeutic potential, Pharmacology & Therapeutics, Volume 200 ,2019, Pages 148-178, ISSN 0163-7258,
https://doi.org/10.1016/j.pharmthera.2019.05.006
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.
Wong, TS.
et al.
G protein-coupled receptors in neurodegenerative diseases and psychiatric
disorders.
Sig Transduct Target Ther
8
, 177 (2023).
https://doi.org/10.1038/s41392-023-
Links to an external site.
01427-2
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Sharon Harrison
Aug 28, 2024 3:01pm
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Reply from Sharon Harrison
Week 1 Discussion
Ion channels and G proteins both play different roles in signal transduction within cells. Ion channels are membrane proteins that allow ions to move across cell membranes (Cen et al., 2024). Sodium, potassium, calcium, and chloride are some examples of ions that can pass through ion channels. In addition to being involved in various psychological processes such as muscle contraction, nerve impulse transmission, and hormone release, they are required to generate electrical signals within cells. Ion channels are typically activated by voltage changes or the binding of specific molecules, such as neurotransmitters or hormones. Because medications commonly target ion channels, they are considered drug targets. For example, medications that block specific ion channels can be used as anesthetics or antiepileptics to prevent electrical signals from transmitting throughout the nervous system. Similarly, medications that modulate ion channel activity can be used to treat cardiac arrhythmias and regulate blood pressure.
G proteins are intracellular signaling proteins that send signals from receptors on the cell’s surface to target molecules inside the cell. When a signaling molecule, such as a hormone or neurotransmitter, binds to a cell surface receptor, it activates a specific G protein, triggering a cascade of events within the cell. These occurrences frequently involve activating or inhibiting enzymes or second messenger systems, which results in changes in cell function. Just like some medications target ion channels, medications can also target G proteins (Yang et al., 2021). They can either activate or inhibit certain G protein-coupled receptors (GPCRs) by modifying their signaling pathways. Beta-blockers, for example, work by blocking GPCRs in cardiac cells, lowering heart rate and blood pressure. Antihistamines, antidepressants, and antipsychotics are all examples of medications that target GPCRs to alter neurotransmitter signaling.
While ion channels primarily regulate ion movement across cell membranes, G proteins act as signal transducers for a wide range of cellular responses initiated by GPCRs. Both ion channels and G proteins are essential components of cellular signaling pathways and are targeted by medications for therapeutic interventions.
Patient Question Response
Genetic, environmental, and lifestyle factors all play a role in mental illness. Although genetics does influence the likelihood of mental health disorders, sharing your grandmother’s genes does not necessarily mean that you will experience the same illness. Stress, trauma, and lifestyle decisions are examples of environmental factors that have a substantial impact on the development and course of mental health disorders (Elliott & Ragsdale, 2023). Even in cases where there is a genetic predisposition, risk can be reduced by positive relationships, leading a healthy lifestyle, and managing stress. If you are worried about your mental health, it may be beneficial to speak with a mental health provider who can assist you in determining your specific risk factors and developing methods to preserve excellent mental health. Regular appointments with a mental health expert can also help you monitor and manage your mental health.
References
Cen, J., Hu, N., Shen, J., Gao, Y., & Lu, H. (2024). Pathological functions of lysosomal ion channels in the central nervous system.
International Journal of Molecular Sciences
,
25
(12), 6565.
https://doi.org/10.3390/ijms25126565
Links to an external site.
Elliott, M., & Ragsdale, J. M. (2023). Nature and/or nurture: Causal attributions of mental illness and stigma.
Social Psychology Quarterly
,
87
(2), 175–196.
https://doi.org/10.1177/01902725231175279
Links to an external site.
Yang, D., Zhou, Q., Labroska, V., Qin, S., Darbalaei, S., Wu, Y., Yuliantie, E., Xie, L., Tao, H., Cheng, J., Liu, Q., Zhao, S., Shui, W., Jiang, Y., & Wang, M.-W. (2021). G protein-coupled receptors: Structure- and function-based drug discovery.
Signal Transduction and Targeted Therapy
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6
(1).
https://doi.org/10.1038/s41392-020-00435-w
Links to an external site.
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Taryn Rae Skiles
Aug 28, 2024 2:30pm
Reply from Taryn Rae Skiles
Signal transduction and the targets of medications consist of several processes. The process of signal transduction is intent on getting the message across the cell membrane to the targets for medications, which are receptors. These receptors are where medications produce their beneficial effects on various disease processes (
Yakubovich, 2024
). Ion channels and g-protein coupled receptors (GPCR) are two important parts of signal transduction. The ion channel is the end target in numerous regulatory pathways. These pathways are initiated by g-protein coupled neurotransmitters and hormones (
Sriram & Insel, 2019
). The g-protein is a metabotropic receptor. It is an intermediate protein that is activated by a neurotransmitter and in return influences the opening of the ion channels and signals a cascade within the cell (
Yakubovich, 2024
). In many cases, GPCR can be inhibitory to successful medication therapy. In particular in antidepressant therapy, many medications are known to indirectly impact the function of these proteins and impact antidepressant efficacy (
Senese et al., 2018
).
If a patient approached me with concern over her family health history of mental illness and her susceptibility, I would first commend the patient for their self awareness of the situation. Additionally, it is important to explain to the patient that there are several factors that impact having a mental illness. While genetics are a factor in some mental illness diagnoses, I would explain that physical health, environment, socioeconomic status, substance abuse and past trauma can all contribute to the onset of mental illness. Lastly, I would explore what particular mental illness their grandparent has because there are direct genetic correlation for certain mental health disorders such as schizophrenia (
Kendall et al., 2024
).
References
Kendall, K., Duffin, D., Doherty, J., Irving, R., Procter, A., & Walters, J. (2024). The translation of psychiatric genetic findings to the clinic.
Schizophrenia Research
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267
, 470–472. https://doi.org/10.1016/j.schres.2023.10.024
Senese, N. B., Rasenick, M. M., & Traynor, J. R. (2018). The role of g-proteins and g-protein regulating proteins in depressive disorders.
Frontiers in Pharmacology
,
9
. https://doi.org/10.3389/fphar.2018.01289
Sriram, K., & Insel, P. A. (2019). G protein-coupled receptors as targets for approved drugs: How many targets and how many drugs?
Molecular Pharmacology
,
93
(4), 251–258. https://doi.org/10.1124/mol.117.111062
Yakubovich, D. (2024). Editorial: Direct modulation of ion channels by g-proteins.
Frontiers in Physiology
,
15
. https://doi.org/10.3389/fphys.2024.1465766
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Emilia Uche
Aug 28, 2024 1:15pm
Reply from Emilia Uche
Difference between Ion Channels and G-proteins
Ion Channels
:
Definition
: Ion channels are membrane proteins that produce pores in the cellular membrane that permit ions to flow through.
Function: When ion channels are activated, a selective transmembrane pore opens, enabling ions to diffuse into or out of cells according to their electrochemical gradient. Exogenous drug molecules can modify ion channels, subject to several signaling pathways’ control.
Illustrations: Certain ligand molecules attach to receptor proteins to cause ligand-gated ion channels, such as glutamate, GABAA, and acetylcholine receptors, to open. Changes in membrane potential cause voltage-gated ion channels to open and close.
Clinical Relevance: To affect cellular reactions, several medications target ion channels. More than 170 ion channel medications are available; some are WHO Essential Medicines.
G Proteins
:
Definition
: Membrane proteins known as G proteins are essential for signal transduction because of their interactions with cell-surface receptors.
Activation: The corresponding G protein is activated when a ligand attaches to a G-protein-coupled receptor (GPCR).
Function: The activated G protein may contact an ion channel or an enzyme in the membrane. G proteins can recognize a variety of ligands, including photons, tiny molecules, and proteins.
Clinical Relevance: A variety of drugs target GPCRs. Because of their ability to either amplify or attenuate impulses, they are crucial for preserving physiological homeostasis.
Mental Illness and Genetics
While genetic predisposition does not ensure that you will suffer from the same mental disease as your grandmother, genetics does play a major influence on the likelihood of having some mental illnesses.
Genetic Impact: With your grandma, you share about half of your DNA with each of your biological parents. If your grandmother had a genetic mental disorder, you might have inherited some of her genes.
Complex Interplay: A mix of genetic, environmental, and lifestyle variables contribute to the development of mental diseases, which are multifactorial. Genetic predisposition interacts with other factors to generate mental disease; it is not a sufficient cause on its own.
Other Factors: Environment: Your upbringing, experiences in life, surroundings, and pressures all have a significant impact on your mental health. An atmosphere that is caring and helpful can lessen the danger, even if you are genetically predisposed.
Epigenetic: Variations in gene expression that take place without changing the DNA sequence are known as epigenetic alterations, and they can affect gene expression. Stress, nutrition, and way of life can all affect these changes.
Unique Deviation:
Non-deterministic: Mental diseases are widely variable, while genetics provides a foundation. While some people without genetic risk factors have mental illness, others who do have risk factors do not.
Resilience: Coping strategies, protective variables, and resilience factors all come into play. Some people have a certain resilience that allows them to handle challenges better than others.
Seek Expert Advice: Speak with a Healthcare Provider: Consult a mental health professional for advice if you are worried about your mental health. They can evaluate your risk factors, talk to you about safeguards, and offer advice.
Early Intervention: It’s important to raise awareness and act early. Frequent evaluations for mental health can aid in spotting any new problems.
Conclusion
In conclusion, G proteins identify a variety of ligands and use intracellular signaling pathways to modify ion channels or other cellular activities. Ion channels, on the other hand, immediately let ions pass through their pores upon ligand binding. Comprehending these distinctions is crucial in creating pharmaceutical substances that could enhance or reduce signaling in diverse physiological settings. Recall that awareness and knowledge are liberating. It can be very different to know your family history and take proactive measures for your mental health. Even though your grandmother and you have similar DNA, your journey is different, and you may take some actions to support mental health.
References
Stevens, E. B., & Stephens, G. J. (2024). Ion Channels as Targets in Drug
Discovery: Outlook and Perspectives.
Springer EBooks
, 1–34.
https://doi.org/10.1007/978-3-031-52197-3_1
Links to an external site.
Rehman, S., & Dimri, M. (2020).
Biochemistry, G Protein Coupled
Receptors
. PubMed; StatPearls Publishing.
https://www.ncbi.nlm.nih.gov/books/NBK518966/
Links to an external site.
DASCAL, N. (2001). Ion-channel regulation by G proteins.
Trends in
Endocrinology and Metabolism
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12
(9), 391–398.
https://doi.org/10.1016/s1043-2760(01)00475-1
Links to an external site.
Andreassen, O. A., Hindley, G. F. L., Frei, O., & Smeland, O. B. (2023). New
insights from the last decade of research in psychiatric genetics:
discoveries, challenges and clinical implications.
World Psychiatry
,
22
(1), 4–24. https://doi.org/10.1002/wps.21034
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Ysamar F Lozano
Aug 28, 2024 12:40pm
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Last reply Sep 1, 2024 1:54pm
Reply from Ysamar F Lozano
Difference Between Ion Channels & G Proteins
Ion channels and G proteins are both signal transductions located in the brain
and play significant roles in activating different chemical messengers (Stahl, 2021). Ion channels are proteins that penetrate a cell membrane, which can help generate the cell’s electrical activity and allow other ions to enter the membrane (Dai, 2023). Ion channels are a part of the signal transduction process through electrical activity that can aid in a trigger response, such as sodium channels opening that leads to depolarization and begins the process of action potential (Dai, 2023). Ion channels are responsible for the functions of the endocrine, cardiovascular, nerve, and immune systems that can later help to target such areas for treatment (Ohya, 2023). Some medications target ion channels to help treat certain diseases. For example, calcium channel blockers help to treat patients with hypertension by preventing calcium from entering the membrane and relaxing the vascular smooth muscle (McGivern & Ding, 2020).
On the other hand, G proteins act through the signal transduction process by inhibiting or activating proteins in the cell when a ligand links to G protein-coupled receptors (GPCRs) outside of the cell surface (Stahl, 2021). GPCRs have been closely linked to antipsychotic medications such as Abilify, Seroquel, and Zyprexa (Komatsu et al., 2019). The two main receptors that antipsychotic medications target is dopamine receptors, which are types of GPCRs (Komatsu et al., 2019). The dopamine receptors have two main classes, D2, D1, and D4. Different antipsychotic medications target D2 receptors through the process of an antagonist, which blocks D2 receptors (Komatsu et al., 2019). This inhibits symptoms of delusions and hallucinations.
Patient Question
When answering the patient’s question of having the same mental illness gene from her grandmother, I would explain to the patient that they have a likelihood of being predisposed to such a gene due to being a close relative. For example, suppose a family member has a history of having a mental illness of either bipolar or schizophrenia. In that case, that family relative is six to eight times more likely to develop either illness compared to someone who does not have a family relative who has one of the mental illnesses (Andreassen et al., 2023). However, being genetically predisposed is not always guaranteed, and other external factors may contribute to such mental illness. A mental illness can oftentimes be developed not only genetically but environmentally as well. This theory has been derived from diathesis-stress model, which is when a mental illness is developed from genetic predisposition but also with stressful conditions as well (APA, 2018). Environmental factors can include stress from life events, trauma/PTSD, or even abusing substances. If this patient is worried about having the same mental illness gene like her grandmother, I would advise the individual to seek out professional help early on rather than waiting a prolong amount of time.
Reference
American Psychological Association [APA]. (2018, April 19). APA Dictionary of Psychology. Retrieved on August 28, 2024, from https://dictionary.apa.org/diathesis-stress-model
Andreassen, O. A., Hindley, G. F. L., Frei, O., & Smeland, O. B. (2023). New insights from the last decade of research in psychiatric genetics: discoveries, challenges and clinical implications.
World psychiatry : official journal of the World Psychiatric Association (WPA)
,
22
(1), 4–24. https://doi.org/10.1002/wps.21034
Dai, G. (2023). Signaling by Ion Channels: Pathways, Dynamics and Channelopathies.
Missouri Medicine
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120
(5), 367–373.
Komatsu, H., Fukuchi, M., & Habata, Y. (2019). Potential Utility of Biased GPCR Signaling for Treatment of Psychiatric Disorders.
International journal of molecular sciences
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20
(13), 3207. https://doi.org/10.3390/ijms20133207
McGivern, J. G., & Ding, M. (2020). Ion Channels and Relevant Drug Screening Approaches.
SLAS Discovery : Advancing Life Sciences R & D
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(5), 413–419. https://doi.org/10.1177/2472555220921108
Ohya, S. (2023). Recent Developments in Ion Channel and Ion-Related Signaling.
International journal of molecular sciences
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24
(19), 14419. https://doi.org/10.3390/ijms241914419
Stahl, S. M. (2021). Stahl’s essential psychopharmacology: Neuroscientific basis and practical applications (5th ed.). Cambridge University Press
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