Sample Answer for NURS 6630 Week 1: Introduction to Neuroscience Included After Question
Introduction to Neuroscience
Modern psychopharmacology is largely the story of chemical neurotransmission. To understand the actions of drugs on the brain, to grasp the impact of diseases on the central nervous system, and to interpret the behavioral consequences of psychiatric medicines, one must be fluent in the language and principles of neurotransmission.
—Dr. Stephen M. Stahl in Stahl’s Essential Psychopharmacology
By using a combination of psychotherapy and medication therapy, psychiatric mental health nurse practitioners are positioned to provide a very unique type of care to clients with psychiatric disorders. To be successful in this role, you must have a strong theoretical foundation in pathophysiology, psychopharmacology, and neuroscience. This foundation will help you assess, diagnose, and treat clients as you relate presenting symptoms to theoretical neuronal functioning.
This week, as you begin to study psychopharmacology, you explore foundational neuroscience. You examine the agonist-to-antagonist spectrum of action of psychopharmacologic agents, compare the actions of g couple proteins to ion gated channels, and consider the role of epigenetics in pharmacologic action.
Note: In previous courses, the term “patient” was used to describe the person receiving medical care. In traditional medicine and nursing, this term is used to describe the person you do something to, and it often refers to a passive recipient of care and services. As you move into the realm of psychiatric mental health, a transition will occur. You will work with individuals who are active participants in their care, and these individuals are generally referred to as “clients” as opposed to “patients.” It is important to note that the term “client” is also favored in other mental health disciplines, such as psychiatry, psychology, and social work.
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NURS 6630 Week 1: Introduction to Neuroscience
As a psychiatric mental health nurse practitioner, it is essential for you to have a strong background in foundational neuroscience. In order to diagnose and treat clients, you must not only understand the pathophysiology of psychiatric disorders, but also how medications for these disorders impact the central nervous system. These concepts of foundational neuroscience can be challenging to understand. Therefore, this Discussion is designed to encourage you to think through these concepts, develop a rationale for your thinking, and deepen your understanding by interacting with your colleagues.
Learning Objectives
Students will:
- Analyze the agonist-to-antagonist spectrum of action of psychopharmacologic agents
- Compare the actions of g couple proteins to ion gated channels
- Analyze the role of epigenetics in pharmacologic action
- Analyze the impact of foundational neuroscience on the prescription of medications
Learning Resources
Note: To access this week’s required library resources, please click on the link to the Course Readings List, found in the Course Materials section of your Syllabus.
Required Readings
Stahl, S. M. (2013). Stahl’s essential psychopharmacology: Neuroscientific basis and practical applications (4th ed.). New York, NY: Cambridge University Press *Preface, pp. ix–x
Note: To access the following chapters, click on the Essential Psychopharmacology, 4th ed tab on the Stahl Online website and select the appropriate chapter. Be sure to read all sections on the left navigation bar for each chapter.
- Chapter 1, “Chemical Neurotransmission”
- Chapter 2, “Transporters, Receptors, and Enzymes as Targets of Psychopharmacologic Drug Action”
- Chapter 3, “Ion Channels as Targets of Psychopharmacologic Drug Action”
Document: Midterm Exam Study Guide (PDF)

Document: Final Exam Study Guide (PDF)
Required Media
Laureate Education (Producer). (2016i). Introduction to psychopharmacology [Video file]. Baltimore, MD: Author.
Note: The approximate length of this media piece is 3 minutes.
Optional Resources
Laureate Education (Producer). (2009). Pathopharmacology: Disorders of the nervous system: Exploring the human brain [Video file]. Baltimore, MD: Author.
Note: The approximate length of this media piece is 15 minutes.
Dr. Myslinski reviews the structure and function of the human brain. Using human brains, he examines and illustrates the development of the brain and areas impacted by disorders associated with the brain.
Laureate Education (Producer). (2012). Introduction to advanced pharmacology [Video file]. Baltimore, MD: Author.
Note: The approximate length of this media piece is 8 minutes.
In this media presentation, Dr. Terry Buttaro, associate professor of practice at Simmons School of Nursing and Health Sciences, discusses the importance of pharmacology for the advanced practice nurse.
NURS 6630 Week 1: Introduction to Neuroscience
To prepare for this Discussion:
- Review this week’s Learning Resources.
- Reflect on concepts of foundational neuroscience.
Note: For this Discussion, you are required to complete your initial post before you will be able to view and respond to your colleagues’ postings. Begin by clicking on the “Post to Discussion Question” link and then select “Create Thread” to complete your initial post. Remember, once you click on Submit, you cannot delete or edit your own posts, and you cannot post anonymously. Please check your post carefully before clicking on Submit!
By Day 3
Post a response to each of the following:
- Explain the agonist-to-antagonist spectrum of action of psychopharmacologic agents.
- Compare and contrast the actions of g couple proteins and ion gated channels.
- Explain the role of epigenetics in pharmacologic action.
- Explain how this information may impact the way you prescribe medications to clients. Include a specific example of a situation or case with a client in which the psychiatric mental health nurse practitioner must be aware of the medication’s action.
Read a selection of your colleagues’ responses.
By Day 6
Respond to two colleagues in one of the following ways:
- If your colleagues’ posts influenced your understanding of these concepts, be sure to share how and why. Include additional insights you gained.
- If you think your colleagues might have misunderstood these concepts, offer your alternative perspective and be sure to provide an explanation for them. Include resources to support your perspective.
Submission and Grading Information
Grading Criteria
Post by Day 3 and Respond by Day 6
To participate in this Discussion:
Making Connections
Now that you have:
- Explored foundational neuroscience
- Examined how medications impact the central nervous system
Next week, you will focus on how neuroscience can be applied to pediatric clients presenting with mood disorders.
A Sample Answer For the Assignment: NURS 6630 Week 1: Introduction to Neuroscience
Title: NURS 6630 Week 1: Introduction to Neuroscience
Explain the agonist-to-antagonist spectrum of action of psychopharmacologic agents.
According to Stahl (2013), the agonist to antagonist spectrum describes the relationships between psychopharmacologic agents and receptors, wherein agonists are drugs that stimulate receptors like neurotransmitters do, and partial agonists are drugs that activate receptors but to a lesser extent than the full agonists, with this class of medications also being referred to as stabilizers. An antagonist is next on the spectrum and is considered neutral in that this class does not act on receptors but works by preventing the actions of agonists. Finally, inverse agonists are the opposite of agonists and work by both blocking available agonists and decreasing activity below baseline even when an agonist is not present (Stahl, 2013).
Compare and contrast the actions of g couple proteins and ion gated channels.
G-protein-linked and ion-channel-linked cascades are both activated by neurotransmitters, with the majority of psychotropic medications utilized today targeting one of these two systems (Stahl, 2013). Both systems work by passing a message from “an extracellular first messenger to an intracellular second messenger” (Stahl, 2013, p. 11). With G-protein-linked systems, the intracellular messenger is a chemical, while with ion-gated channel systems, the intracellular messenger can be an ion (Stahl, 2013). Unlike G-protein-linked receptors, ion gated channels are both receptors and channels in that the amino acid strings forming the channel can allow ions through but also have distinct receptor sites for some ions, neurotransmitters, and drugs. Medications that work by targeting G-protein linked receptors often have a delay of onset because effects result from “downstream” actions occurring from changes to gene expression or protein synthesis. In contrast, drugs that effect ionotropic receptors, altering the flow of ions, can have almost immediate effects, and include such drug classes as Benzodiazepines (Stahl, 2013).
Explain the role of epigenetics in pharmacologic action.
Epigenetics refers to the system that determines whether or not a gene is activated or silenced. Activated genes are transcribed resulting in the creation of RNA or proteins specific to that gene, while silenced genes are ignored (Stahl, 2013). Chromatin is composed of histones which are wrapped around DNA strands, serving as gates for transcription factors. Specific enzymes can either open or shut this gate system leading to the activation or silencing of that gene. Drugs that activate the enzymes histone acetyl transferase, DNA demethylase, and histone demethylase lead to the opening of the gate and the transcription or activation of that gene. Drugs that activate histone deacetylase, DNA methyl-transferase, and histone methyl-transferase enzymes shut the gate, thus preventing the entrance of transcription factors and silencing that gene (Stahl, 2013). Epigenetic variations have been identified as playing a significant role in individual responses to psychotropic medications. According to Reynolds, McGowan, and Dalton (2014), single nucleotide polymorphisms affecting neuronal receptor and transporter structures have been identified as playing a significant role in the wide variations noted in medication effectiveness and side effect severity seen among psychiatric patients.
Explain how this information may impact the way you prescribe medications to clients. Include a specific example of a situation or case with a client in which the psychiatric mental health nurse practitioner must be aware of the medication’s action.
According to Cho et al. (2018), one study found that over 50% of medications prescribed outpatient to geriatric patients meets one or more of the STOPP (Screening Tool of Older Persons’ Prescriptions) criteria highlighting potential inappropriate prescribing of medications. This patient population may be more at risk of experiencing side effects due to the increased likelihood of existing comorbidities and polypharmacy (Cho et al., 2018). One possible scenario would be if I were to prescribe an ionotropic medication for a geriatric patient with a history of falls and/or being stages of dementia. The nearly immediate effects of this medication class could lead to increased risk of falls and patient injury if potential side effects include sedation.
References:
Cho, H., Choi, J., Kim, Y.-S., Son, S. J., Lee, K. S., Hwang, H.-J., & Kang, H.-Y. (2018). Prevalence and predictors of potentially inappropriate prescribing of central nervous system and psychotropic drugs among elderly patients: A national population study in Korea. Archives of Gerontology & Geriatrics, 74, 1–8. https://doi-org.ezp.waldenulibrary.org/10.1016/j.archger.2017.08.013
Reynolds, G., McGowan, O., & Dalton, C. (2014). Pharmacogenomics in psychiatry: the relevance of receptor and transporter polymorphisms. British Journal of Clinical Pharmacology, (4), 654. https://doi-org.ezp.waldenulibrary.org/10.1111/bcp.12312
Stahl, S. M. (2013). Stahl’s essential psychopharmacology: Neuroscientific basis and practical applications (4th ed.). New York, NY: Cambridge University Press *Preface, pp. ix–x
A Sample Answer 2 For the Assignment: NURS 6630 Week 1: Introduction to Neuroscience
Title: NURS 6630 Week 1: Introduction to Neuroscience
Explain the agonist-to-antagonist spectrum of action of psychopharmacologic agents.
Full agonists allow a receptor site to open up an ion channel to the maximum amount and frequency which is allowed by that particular binding site which causes the maximum amount of downstream signal transduction possible to be utilized at the binding site. The ion channel can open more frequently than with a full agonist alone but requires the help of a second receptor site. An antagonist causes a stabilization in the receptor sites in resting phases which is the same mechanism of action at the receptor site when an agonist is not present. Because there are no changes whether an antagonist is present or not, it is said to be neutral or silent.
Partial agonists cause changes in receptors so that ion channels open to a greater extent and with more frequency that at a resting state but less than when a full agonist is present. Antagonists reverse partial antagonists just as it reverses full agonists and result in the receptor site returning to its state of rest. Partial agonists produce ion flow and downstream signal transduction which is more than at a resting state but less than that of a full agonist. When there are unstable neurotransmissions within the brain, a balance must be found to stabilize the receptor output so that there is not too much or too little downstream action occurring. Partial agonists are also referred to as stabilizers since they are typically able to cause an even reaction between extremes of too much or too little action potential (Stahl, 2013).
Compare and contrast the actions of g couple proteins and ion gated channels.
A class of receptors linked to G proteins are a major target of psychotropic drugs. The G couple proteins have the structure of seven transmembrane regions, spanning the membrane seven times. Each region of the membrane is arranged around a
central core which contains a binding site for a neurotransmitter. Drugs can interact at a particular neurotransmitter binding site or at other sites, also called allosteric sites within a receptor. This binding can lead to various modifications of receptor actions by either partially or fully mimicking or blocking any neurotransmitter function which would normally occur at a specific receptor site. Downstream molecular processes can be changed by drug actions as when phosphoproteins are activated or inactivated which results in a difference in which enzymes, receptors, or ion channels are modified by the neurotransmission. These drug actions can also lead to changes in which genes are expressed, altering which proteins are synthesized and which functions are amplified, from synaptogenesis, to receptor and enzyme synthesis, to communication with downstream neurons innervated by the neuron with the G-protein-linked receptor. As a result, drug-induced alterations at the G-protein-linked receptor site can cause actions on psychiatric disorders or symptoms (Stahl, 2013).
Like G proteins, ligand-gated ion channels are a type of receptor which also forms an ion channel. For this reason, they are both ligand-gated ion channel and also ionotropic receptors or ion-channel-linked receptors. They have dual functions, hence the two names. Ligand-gated ion channels consist of long strings of amino acids which are gathered as subunits around an ion channel. There are many binding sites around these subunits for neurotransmitters, ions and drugs. Complex proteins have sites where ions can pass through a channel or bind to the channel, or where a neurotransmitter can act as a binding site and where natural substances or drugs can bind to a site different than where the neurotransmitter binds resulting in an increase or decrease to the sensitivity of a channel opening. In psychopharmacology, the ion channels that are the most important are those that control sodium, calcium, chloride, and potassium. Full agonists will directly change the receptor site to open the ion channel. Antagonists will cause a steady state at the receptor in its resting state which is similar to how a receptor responds when there is no agonist present. Alternatively, drug-induced modifications which occur with ionotropic receptors cause immediate effects by changing the flow of ions resulting in an immediate clinical onset as when medications such as anxiolytics and hypnotics are used. Some drugs that act at the G-protein-linked receptor sites may have a delayed response caused by an instigation in cellular functions that become activated by the signal transduction cascade (Stahl, 2013).
Explain the role of epigenetics in pharmacologic action.
In genetics, there is a DNA code which transcribes specific types of RNA or proteins within cells. While there are greater than 20,000 genes within the human genome, not every gene is expressed, even within the brain. Epigenetics goes a step further than genetics in that there is a determination whether a given gene is made into specific RNA and protein or instead it is just simply ignored or silenced. Further definition states that if a genome is a glossary of all “words” related to protein, than the epigenome is the “story” of all of those “words” into something that is cohesive. The genomic makeup of potential proteins is the same within every single neuron and cell in the body. What causes a normal neuron to malfunction, as in psychiatric diagnoses, or how a neuron winds up a neuron rather than a liver cell is all the result of whether or not specific genes are expressed or silenced. Neurons that are functioning improperly are often impacted by genes with abnormal sequences and if these genes are expressed rather than silenced, mental disorders can ensue. Brain development is not only dependent on inherited genes, but whether or not abnormal genes are expressed, and/or normal genes are silenced. There are many factors which regulate whether or not genes are expressed or silenced and include neurotransmission, the gene makeup, drugs and environment. All of these factors help decide whether or not the brain is one full of learning and memories or drug abuse, stress and psychiatric disorders and whether or not there can be improvement with medications and therapy (Stahl, 2013).
Explain how this information may impact the way you prescribe medications to clients. Include a specific example of a situation or case with a client in which the psychiatric mental health nurse practitioner must be aware of the medication’s action.
In depth knowledge regarding medications, pharmacokinetics and pharmacodynamics are important prior to prescribing. In addition to this, one must understand genetics and factors regarding medication uptake and absorption. Farmer (2014) discusses psychopharmacological treatment from a social work perspective and states that a new way of thinking about mental illness is evolving. The National Institute of Mental Health has worked on a project (the Research Domain Criteria RDoC) to change the thought process behind mental illness diagnoses. The RDoC utilizes data regarding pathophysiology, especially related to genomics and neuroscience when it comes to understanding mental illness. Investigation of the biological underlying of mental disorders is being focused on and a new understanding of different dimensions of functioning related to positive and negative valence systems, cognitive systems, systems for social processes, and arousal/modulatory systems are being included and studied as well as the analysis of genes, molecules, cells, neural circuits, physiology. Client behaviors and self-reports are also considered. The idea is to link neurobiology with mental illness diagnoses and find better medications to treat specific mental disorders. We must understand that psychotropic medications work in the brain and CNS to affect the level of a neurotransmitter. Human behavior is the result of neural activity where an axon sends chemical and electrical messages to receiving neurons and a synapse is a communication point between neurons and where an action potential takes place. As PMHNPs, we must understand the mechanism of action in how a medication works, whether it is an agonist or antagonist, and how the major neurotransmitters (acetyl-choline, norepinephrine, dopamine, serotonin, gamma aminobutyric acid, glutamate) are affected by specific medications. Medications have different effects based on factors such as client age, gender, race and ethnicity. More studies are needed how race and ethnicity may affect medications as pharmacokinetics and pharmacodynamics, as are influenced by genetic factors as well as the environment which includes lifestyle, behavioral patterns, and social interactions. One person’s response to a medication will be determined by gene–environment interaction (Farmer, 2014).
Understanding that psychiatric disorders such as major depressive disorder, drug addiction, and schizophrenia can have multiple gene involvements rather than “one gene/one disease” relation can assist with finding the right medications and treatments for clients. Understanding epigenetic modifications (histone acetylation and deacetylation, DNA methylation) and how these can result in changes in gene expression is looking to be the future of treating psychiatric disorders (Mahgoub & Monteggia, 2013).
PMHNPs must be aware at this time, when prescribing medications such as an SSRI or SNRI, these medications take time to reach therapeutic effect. Patients must be well educated that they will not feel “better” instantly and must be counseled to stay the course with medication compliance and therapies to achieve maximum benefit.
References
Farmer, R. L. (2014). Interface between psychotropic medications, neurobiology, and mental illnesses. Smith College Studies in Social Work, 84(2-3), 255-272.
Mahgoub, M., & Monteggia, L. M. (2013). Epigenetics and psychiatry. Neurotherapeutics, 10, 734-741.
Stahl, S. M. (2013). Stahl’s essential psychopharmacology: Neuroscientific basis and practical applications (4th ed.). New York, NY: Cambridge University Press
A Sample Answer 3 For the Assignment: NURS 6630 Week 1: Introduction to Neuroscience
Title: NURS 6630 Week 1: Introduction to Neuroscience
The Agonist-to-Antagonist Spectrum of Action of Psychopharmacologic Agents
The agonist-to-antagonist spectrum is made up of two words that are important to be understood singly. An agonist is a chemical that binds to a receptor thereby activating it to trigger a biological response. Antagonist, on the other hand, blocks the response mediated by the agonist. Antagonist causes an action opposite to that of the agonist, which reaction is called reverse agonist, to occur (Stahl, 2013). Once an agonist binds to a receptor, a full/conventional or partial agonist reaction may occur. As the concentration of the agonist increases, the occupancy of receptors also increases, consequently increasing the response (Stahl, 2013). The antagonist effect of a drug occurs when the antagonist increases in concentration thereby surmounting the activation effect of the agonist and inhibiting their response. A full agonist produces the maximal response system while a partial agonist produces a submaximal one.
The Actions of G-Couple Proteins and Ion-Gated Channels
There are two broad families of protein receptors involved in the opening and closing of the postsynaptic ion channels, namely g-couple proteins and ion-gated channels (Laureate Education Producer, 2016i). G protein-coupled receptors/seven transmembrane (7-TM) receptors form the largest protein family (about 600 – 1000 members) and are involved in many normal biological and pathological conditions (Inanobe & Kurachi, 2014). They have a diverse function and recognize many ligands including proteins, small molecules, and photons (Stahl, 2013). They specifically maintain the electrochemical gradient across the cell.
Ligand-gated ion channels (LGICs), on the other hand, are transmembrane ion channels found in the cellular membrane. They help in the opening and closing of the membrane to allow for the passage of ions such as Na+, K+, Ca2+, and/or Cl−. The human genome has over 400 genes for ion channels. Their opening and closing are dependent on the attachment of a chemical messenger, a ligand, such as a neurotransmitter (Inanobe & Kurachi, 2014).
The Role of Epigenetics in Pharmacologic Action
Different patients respond differently to various medications due to the genetic alterations that occur at an individual level. Epigenetic allows the understanding of these modifications in gene expressions that occurs in the DNA sequence of a gene for some patients. These genetic modifications are called epigenetic alterations. They include methylation, phosphorylation, acetylation, and ubiquitylation of DNA (Swathy & Banerjee, 2017). These alterations make many patients not to respond to standard therapies. The alterations not only regulate gene expression but also other cellular and biological functions related to allostasis, homeostasis, and disease (Rasool et al., 2015). These processes generally influence pharmacogenetics activities such as the contribution of receptors, drug transporters, and drug-metabolizing enzymes.
Impacts of Epigenetics in Pharmacologic and Examples of Psychiatric Mental Health Cases
The epigenetic alterations that occur at individual levels require doctors to provide personalized treatments to patients. Since epigenetic alterations differ from one patient to the other, physicians should do genetic screenings of patients to guide disease prediction and prevention and decision making on the medical recommendations and lifestyle and disease management practices that are best at an individual level (Rasool et al., 2015). For instance, in the case of Schizophrenia, the genetic modifications occur in the histones or DNA such as DNA methylation. For histone modification, HDAC (histone deacetylase) inhibitors drugs are recommended because they up-regulate the levels of reelin and GAD67. HMT (histone demethylase) inhibitors also prevent the demethylation of the H3K4 histone protein. As for DNA methylation, DNMT (DNA Methyltransferases) inhibitors are recommended because they raise the reeling levels of proteins and protein and GAD67 (Swathy & Banerjee, 2017). This requires physicians to make an individual genetic screening of a patient to determine the particular epigenetic alteration they experience before recommending drug prescriptions that are best and specific to them.
References
Inanobe, A., & Kurachi, Y. (2014). Membrane channels as integrators of G-protein-mediated signaling. Biochimica Et Biophysica Acta (BBA)-Biomembranes, 1838(2), 521-531.
Laureate Education (Producer). (2016i). Introduction to psychopharmacology [Video file]. Baltimore, MD: Author.
Rasool, M., Malik, A., Naseer, M. I., Manan, A., Ansari, S. A., Begum, I., & Kamal, M. A. (2015). The role of epigenetics in personalized medicine: challenges and opportunities. BMC medical genomics, 8(S1), S5.
Stahl, S. M. (2013). Stahl’s essential psychopharmacology: Neuroscientific basis and practical applications (4th ed.). New York, NY: Cambridge University Press *Preface, pp. ix–x
Swathy, B., & Banerjee, M. (2017). Understanding epigenetics of schizophrenia in the backdrop of its antipsychotic drug therapy. Epigenomics, 9(5), 721-736.