Introduction to Neuroscience Week 1
Explain the agonist-to-antagonist spectrum of action of psychopharmacologic agents.
In order to explain the spectrum of action involving agonists and antagonists, one must understand their basic functions. An agonist is a chemical which binds to a particular receptor which leads to, or triggers, a biologic response. An antagonist will also bind itself to a receptor site but will instead inhibit the biologic action by occupying the receptor site and preventing an agonist from binding and producing a reaction. The spectrum of action of psychopharmacologic agents created by an agonist are separated and measured through the comparison of the biologic responses caused by the endogenous agonist, which is naturally present in the body. Exogenic agonists will produce different responses based on their efficacy; when the agonist produces a greater response than the endogenous agonist, it is referred to as a super agonist. Partial agonists are labeled as such because the response they create is not as productive as the endogenous agonist or full agonist. There are also inverse agonists which not only inhibit the normal agonist reaction, but also produce the opposite pharmacologic reaction. With so many drugs that can induce different agonist reactions, there are many different options for clients to find a specific medication which works best for them.
Compare and contrast the actions of g couple proteins and ion gated channels.
After addressing agonists and antagonists, it is natural that different type of receptor sites such as ion gated channels and g-couple proteins be reviewed. Both the ion gated channels and g-couple proteins have a receptor site where an agonist can bind in the extracellular space. When an agonist binds to the ion gated channel receptor site, the ion gated channel will open up allowing ions such as potassium, sodium, chloride, or calcium, which will create an intracellular electrical signal (Stahl, 2013). With g-couple proteins, when an agonist attaches to a g-protein coupled receptor, it goes through a conformational change and begins to trade guanosine diphosphate (GDP) to guanosine triphosphate (GTP) through the use of a subunit. The subunit will then dissociate and target proteins which will release a second messenger which will be the cause of the biological reaction (Stahl, 2013).
Explain the role of epigenetics in pharmacologic action.
Epigenetics has to do with modifying genetic expression without having any changes to the genetic code. Studies are beginning to show that epigenetic mechanisms are regulating gene expression at many different levels and has been the cause of the development of new epigenetic therapies. The discovery in which epigenetic gene regulation is as much a part of normal phenotypical activity as it is a part of the development of various diseases and disorders, has created more studies in how new treatments can be formed to manipulate its role. Drugs are now being developed to regulate epigenetic mechanisms which can positively effect diseases manifested in clients and further studies are showing where older medications have been lacking in efficacy (Moosavi & Motevalizadeh Ardekani, 2016).
Explain how this information may impact the way you prescribe medications to clients.
All of the information provided, whether it is about the medication in which the agonists have a certain level of action, how those agonists bind to their receptors and create the change needed, or how new treatments can be derived from increasing knowledge of epigenetic mechanisms, will have a major impact on how medication is prescribed to the client. Clients already have such an individualized agenda when it comes to their own experiences, diseases, and disorders, that the more medications can be provided, the better chances are to treat them based on their needs. With the new developments in medication dealing with the agonist-to-antagonist spectrum and new research in epigenetics, better therapeutic methods and agents will be available.
Moosavi, A., & Motevalizadeh Ardekani, A. (2016). Role of Epigenetics in Biology and Human Diseases. Iranian biomedical journal, 20(5), 246-58.
Rose, J., & Levin, E. (1992). Concurrent agonist-antagonist administration for the analysis and treatment of drug dependence. Pharmacology Biochemistry and Behavior, Vol. 41 Issue 1, 219-26.
Stahl, S. M. (2013). Stahl’s essential psychopharmacology: Neuroscientific basis and practical applications (4th ed.). New York, NY: Cambridge University Press *Preface, pp. ix–