NURS 6630 Week 1: Introduction to Neuroscience

Sample Answer for NURS 6630 Week 1: Introduction to Neuroscience Included After Question

NURS 6630 Week 1: Introduction to Neuroscience 

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. 

Photo Credit: [cgtoolbox]/[Vetta]/Getty Images 

NURS 6630 Week 1: Introduction to Neuroscience 
NURS 6630 Week 1: Introduction to Neuroscience

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 

 

Note: All Stahl resources can be accessed through the Walden Library using this link. This link will take you to a log-in page for the Walden Library. Once you log into the library, the Stahl website will appear. 

 

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: 

  1. Explain the agonist-to-antagonist spectrum of action of psychopharmacologic agents. 
  1. Compare and contrast the actions of g couple proteins and ion gated channels. 
  1. Explain the role of epigenetics in pharmacologic action. 
  1. 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  

 

To access your rubric: 

Week 1 Discussion Rubric 

 

Post by Day 3 and Respond by Day 6 

 

To participate in this Discussion: 

Week 1 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

To go to the next week: 

10 days ago  

Courtney Cox  

Wk 1  

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  1. 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).   

  1. 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). 

  1. 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. 

  1. 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 

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11 days ago  

Elaina Railey  

week 1  

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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 

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11 days ago  

Jodi Essary  

Week 1 – Jodi Essary  

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  1. Explain the agonist-to-antagonist spectrum of action of psychopharmacologic agents.  

The spectrum of agonists to antagonists describes how substances, either occurring naturally (ligand) or synthetically such as psychopharmacologic agent, effect receptor sites (Stahl, 2008). The agonists are agents can increase an action on the receptor by mimicking a naturally occurring agent (Strange, 2008). An antagonist acts by blocking the receptor site to decrease the action of agents (Strange, 2008). Substances can also be partial agonists, which is an action that ranges between full agonist and full antagonist. Instead of increasing an action to the maximum level or blocking the action completely, it is an action that is somewhere in between the two levels (Strange, 2008). Many psychopharmacologic agents work by acting on G-protein-linked systems and ion-channel systems because these are triggered by neurotransmitters (Stahl, 2008).  

  1. Compare and contrast the actions of g couple proteins and ion gated channels.  

G protein-coupled and ion-gated channels are both triggered by neurotransmitters (Stahl, 2008). G protein-coupled receptors (GPCRs) have seven transmembrane alpha helices (Strange, 2008). G proteins have three subunits (alpha, beta, and gamma). Ion-gated channels can be activated by electrical signals and neurotransmitters (Stahl, 2008). Ion-gated channels change the flow of ions, causing an almost-immediate effect and GPCRs take longer to work because they may make changes to cellular function over time (Stahl, 2008).  

  1. Explain the role of epigenetics in pharmacologic action.  

Epigenetics is the study of gene expression, or which genes are turn off or on (Stahl, 2008). Pharmacologic actions can turn genes on or off to gain a desired effect. Epigenetic regulation of brain functions is important in the etiology of psychiatric disorders (Boks, et al., 2012). Epigenetic mechanisms, such as DNA methylation and histone acetylation, are affected by many pharmaceuticals, including psychiatric drugs (Boks, et al., 2012).  

 

  1. 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.  

Thorough knowledge of how medications work will allow the nurse practitioner to prescribe the best medication for the client. For example, knowing that many anxiolytics work on inotropic receptors and will work very quickly to calm a client in an acute situation rather than prescribing an antidepressant that works on GPCRs and will take much longer to help with an acute episode. 

References 

Boks, M. P., de Jong, N. M., Kas, M. J., Vinkers, C. H., Fernandes, C., Kahn, R. S., Mill, J., & 

Ophoff, R. A. (2012). Current status and future prospects for epigenetic psychopharmacology. Epigenetics, 7(1), 20-8. 

Stahl, S. M. (2008). Essential Psychopharmacology Online. Retrieved from 

http://stahlonline.cambridge.org.ezp.waldenulibrary.org/essential_4th.jsf 

Strange, P. G. (2008). Agonist binding, agonist affinity and agonist efficacy at G protein-coupled 

receptors. British Journal of Pharmacology, 153(7), 1353-63. doi: 10.1038/sj.bjp.0707672 

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