Week 1 Discussion
Discussion: Foundational Neuroscience
- 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).
- 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).
- 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).