NURS 4430 Week 2 Neurotransmitters and Receptor Theory

Receptors and neurotransmitters are like a lock-and-key system. Just as it takes the right key to open a specific lock, it takes the right neurotransmitter to bind to a specific receptor. Not surprisingly, as it concerns psychopharmacology, the pharmacotherapeutics that are prescribed must trigger the release of certain neurotransmitters that bind to the correct receptors in order to elicit a favorable response for the patient. The mechanism of this binding and the response that follows reflects receptor theory and lies at the foundation of pharmacology.

This week, you will continue your examination of neuroanatomy and neuroscience as you engage with your colleagues in a Discussion. You will also explore the potential impacts of foundational neuroscience on the prescription of pharmacotherapeutics.

Learning Objectives 

Students will:

  • Analyze the agonist-to-antagonist spectrum of action of psychopharmacologic agents
  • Compare the actions of g coupled 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

  • Camprodon, J. A., & Roffman, J. L. (2016). Psychiatric neuroscience: Incorporating pathophysiology into clinical case formulation. In T. A. Stern, M. Favo, T. E. Wilens, & J. F.
  • Rosenbaum. (Eds.), Massachusetts General Hospital psychopharmacology and neurotherapeutics (pp. 1–19). Elsevier.

Required Media: The University of British Columbia. (n. d.). Neuroanatomy videos.

Discussion: Foundational Neuroscience

As a psychiatric nurse practitioner, it is essential for you to have a strong background in foundational neuroscience. In order to diagnose and treat patients, 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.

For this Discussion, review the Learning Resources and reflect on the concepts of foundational neuroscience as they might apply to your role as the psychiatric mental health nurse practitioner in prescribing medications for patients.

By Day 3 of Week 2

Post a response to each of the following:

  1. Explain the agonist-to-antagonist spectrum of action of psychopharmacologic agents, including how partial and inverse agonist functionality may impact the efficacy of psychopharmacologic treatments.
  2. Compare and contrast the actions of g coupled proteins and ion gated channels.
  3. Explain how the role of epigenetics may contribute to pharmacologic action.
  4. Explain how this information may impact the way you prescribe medications to patients. Include a specific example of a situation or case with a patient 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 of Week 2

Respond to at least two of your colleagues on two different days 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.

Neurotransmitters and Receptor Theory Sample Paper

Transmission of electrical impulses from one neuron across the synapse to a different neuron or a cell is facilitated by neurotransmitters. Examples of neurotransmitters that facilitate central nervous functions include amino acids (GABA, aspartate, and glutamate), amines (catecholamines, acetylcholine, and serotonin), peptides (neuropeptide Y) and gases such as nitric oxide (Sheffler, Reddy & Pillarisetty, 2020). These neurotransmitters have specific receptors which bind to psychopharmacologic agents to either cause agonistic or antagonistic actions as illustrated hereafter.

Agonist-to-antagonist Spectrum of Action of Psychopharmacologic Agents

Psychopharmacologic agents are drugs used in the management of a wide spectrum of psychiatric disorders including behavioral disorders, depression, anxiety or stressor-related conditions. The drugs can either exhibit agonistic or antagonistic activities at the receptor site (Katzung, 2018). While agonists activate the receptors, antagonists block the receptors. For example, in the etiology of Schizophrenia, the Dopamine hypothesis is widely accepted. It is believed that excess Dopamine neurotransmission causes Schizophrenic symptoms. 

This has been evidenced by the presence of higher levels of Dopamine receptors in Schizophrenic patients. Management of Schizophrenia therefore utilizes drugs that block the Dopamine receptors (antagonists) for example Chlorpromazine (Katzung, 2018). Contrarily, the pathophysiology of neurodegenerative diseases such as Parkinson disease (PD) reveals decreased dopamine levels and receptors (Katzung, 2018). Therefore, dopamine agonists such as Levodopa are used in the management of PD.

Partial agonists bind and activate receptors but only have partial efficacy (Berg & Clarke, 2018). An example, used as an anxiolytic is Buspirone. Partial agonists exhibit both agonistic and antagonistic actions for example, while Buspirone is a partial agonist for 5HTA1 receptors; it’s an antagonist for D2 receptors (Katzung, 2018)). Therefore, it can be used both as an anxiolytic and antidepressant drug. Inverse agonists bind to receptors however, producing effects opposite to the agonist (Berg & Clarke, 2018). Naltrexone, a partial inverse agonist, is used in the management of opioid addiction.

G-coupled proteins and Ion-gated Channels

G-protein receptors and ligand gated ion channels are both cell surface receptors. They are both found on the membrane of the cells. While ligand gated ion channels are controlled by neurotransmitters to release ions, a G-protein depends on the second messenger system to act (Miller & Lappin, 2020). Therefore, due to the difference in the mechanism of stimulation, ligand gated ion channels take less time (milliseconds) to be activated compared to G-protein receptors which take a bit longer time (seconds). Additionally, examples of ligand gated ion channels include nicotinic acetylcholine receptors and GABA A receptors while G-coupled receptors examples include muscarinic acetylcholine receptors and adrenoceptors (Katzung, 2018; Miller & Lappin, 2020).

Role of Epigenetics in Pharmacologic Action

It has been shown that the gene environment influences its expression. Epigenetics, an emerging scientific area, is the study of how the environment, child development, aging or diet influences the changes in gene expression (Ganesan et al., 2019). Epigenetic variations have been linked to multiple conditions such as a variety of cancers and psychiatric disorders. Therefore, understanding the multiple epigenetic mechanisms and pathways involved is the key to treating such conditions. 

Drugs such as Decitabine have been used as epigenetic anticancer drugs (Ganesan et al., 2019). This drug manipulates the epigenetic changes and genes therefore, capable of halting the neoplastic progression. Currently, the epigenetic drugs are used alongside routine therapy, an approach which has produced myriad beneficial effects.

Significance of the Information

The information about the pharmacology of drugs is crucial in healthcare. A competent care provider must know the mechanism of actions and potential adverse effects of the drugs. For example, in the management of PD, the nurse must be aware of the pathophysiological mechanisms; the dopamine levels and its receptors. In this case, a nurse is aware that Dopamine agonists are indicated for the management and Dopamine antagonists would worsen the effects.


  • Berg, K. A., & Clarke, W. P. (2018). Making sense of pharmacology: Inverse agonism and functional selectivity. The International Journal of Neuropsychopharmacology, 21(10), 962–977. doi:10.1093/ijnp/pyy071
  • Ganesan, A., Arimondo, P. B., Rots, M. G., Jeronimo, C., & Berdasco, M. (2019). The timeline of epigenetic drug discovery: from reality to dreams. Clinical Epigenetics, 11(1), 174. doi:10.1186/s13148-019-0776-0
  • Katzung, B. (2018). Basic & clinical pharmacology (14th ed.). New York: McGraw-Hill.
  • Miller, E. J., & Lappin, S. L. (2020). Physiology, Cellular Receptor. In StatPearls. Retrieved from
  • Sheffler, Z. M., Reddy, V., & Pillarisetty, L. S. (2021). Physiology, Neurotransmitters. In StatPearls. Retrieved from