Introduction to Neuroscience—Initial Post 1. Explain the agonist-to-antagonist spectrum of action of psychopharmacologic agents. The agonist-to- antagonist spectrum of action of psychopharmacologic agents refers to how certain drugs behave under specifi

Introduction to Neuroscience—Initial Post 1. Explain the agonist-to-antagonist spectrum of action of psychopharmacologic agents. The agonist-to- antagonist spectrum of action of psychopharmacologic agents refers to how certain drugs behave under specific biological and chemical conditions. There are four main categories of this spectrum that include: agonist, partial agonist, antagonist, and inverse agonist (Stahl, 2013). An agonist causes a conformational change that triggers a maximum signal transduction response. In other words, an agonist binds to a receptor site, activates the receptor, and causes a biological response. Partial agonist or “stabilizers” will illicit a response, but to a lesser degree than an agonist. An antagonist will block the activity of the agonist if the agonist is present; however the antagonist itself causes no changes to the receptor. The inverse agonist can block the activity of an agonist or drastically reduce the activity of the agonist (Stahl, 2013). 2. Compare and contrast the actions of g couple proteins and ion gated channels. There are several important psychopharmacological drugs that target ion gated channels and g-couple proteins to illicit specific chemical responses. G couple proteins and ion gated channels are two of the most important signal transduction systems. These systems are triggered by neurotransmitters and involve a variety of molecules known as “messengers” that carry out the complex cascade chain of events. Ion gated channels function to regulate the flow of ions in and out of the cell membrane. Ion gated channel receptors bind to ligands producing a conformational change that causes the channel to widen or narrow. This chemical cascade is triggered by the presence of neurotransmitters (Stahl, 2013).