Discussion: Neurotransmitters and Receptor Theory

Question 1

Mainly, agonists refer to agents that normally activate receptors upon their binding, similar to the impact of hormones, neurotransmitters, and other endogenous regulators. Some examples of agonists include inverse agonists and partial agonists. It is critical to note that naturally occurring neurotransmitters stimulate receptors, termed agonists. Also, some medications stimulate receptors and are hence deemed agonists. On the other hand, antagonists oppose a specific activity by blocking the receptors’ effectiveness to prevent the binding of endogenous molecules or other drugs for activation. Hence, antagonists are at times termed as “silent.” Inverse agonists often bind to the agonist binding site on the receptor; nonetheless, it elicits an opposite pharmacological impact (Van Baelen et al., 2022).

On the other hand, partial agonists have moderate activity, especially when compared to full agonists, generating half the effect. It is an agonist-antagonist since it blocks the binding of other molecules while generating limited activity. Thus, both inverse and partial antagonists influence the outcomes and efficacy of the treatments. 

Question 2

By definition, G couple proteins are integral membrane proteins utilized by cells to change extracellular cells into intracellular responses. Ion-gated channels, on the other hand, are large and multisubunit receptors. They form a membrane ion channel which, when open, permits passage of K+ and Na+. It is crucial to note that neurotransmitters also trigger ion-gated channels and the G protein. There are four critical elements in a G protein-linked system, including neurotransmitter, also known as the first messenger. G protein-coupled receptor is the second element and has seven transmembrane regions (Yudin & Rohacs, 2019). The last element is an enzyme that synthesizes a second messenger, particularly when activated.

Additionally, the G protein-coupled receptors are composed of a large family of receptors on the cellular plasma membranes that use a G protein to transmit signals in a cell. Also, disorders in this protein coupled with receptors result in illnesses as they serve different functions within the body. It is also critical to note that the G protein often elicits different responses. This is due to the interaction with G protein subunits such as ? subunits and ? subunits generated from G-protein subdivision due to binding with the guanosine triphosphate.

Ion-gated proteins are divided into ligand-gated ion channels, mechanically-gated ion channels and voltage-gated ions. Ligand-gated ion channels refer to the inotropic receptors that either open or close in response to the binding of ligands. Voltage-gated ion channels either close or open in response to membrane potential modifications. Mechanically-gated ion channels often respond to tension in the membrane by altering their conformation between a closed and an open state (Yudin & Rohacs, 2019). It is crucial to note that ion channel receptors is an essential constituent of nervous system signalling and permits direct and rapid conversion of chemical neurotransmitter into electric current. 

Question 3

Typically, regulation of gene activity by epigenetics has been proved to be essential in maintaining normal phenotypic cell activity. It is also fundamental in diseases, including neurodegenerative disorders like Alzheimer’s. DNA methylation is the other known cause of disease alterations (Mews et al., 2021). Consequently, how individuals respond to different drugs results from cellular changes. Again, the cellular changes are due to epigenetic or heterogeneity alterations. Lastly, new classes of drugs often regulate epigenetic mechanisms to counteract human disease states. 

Question 4

Psychiatric nurse practitioners must comprehend drugs’ physical and biological aspects before prescribing medication to persons with psychiatric conditions. This is because such drugs directly impact the neurons and the receptors; hence crucial for nurse practitioners to comprehend the mechanism of action (Nyttingnes & Rugkåsa, 2021). Additionally, it is instrumental for the practitioners to consider the patient’s family history and the genetic implications on both treatment and diagnosis. A good example is that of a patient who has dementia. In such a case, the physician must be able to choose the best medication based on the patient’s behavioral, psychological and psychosis symptoms. This is because treating mental illnesses might have side effects often caused by aging drug metabolism and its clearance. Notably, alterations of age-induced epigenetics lead to pharmacokinetic and pharmacodynamics changes, which tend to influence the antipsychotic action of drugs. Further, epigenetic changes led to the altered efficacy of antipsychotics and increased side effects due to histone modifications. Recognizing such changes would greatly assist when making prescription decisions to ensure the maximum efficacy of the preferred medication