Psychoactive medications vary in how they affect activity at the synapse. Agonists increase the neurotransmitter effect while antagonists block the neurotransmitter effect (.
An agonist to antagonist to inverse agonist spectrum
Psychoactive medications vary in how they affect activity at the synapse. Agonists increase the neurotransmitter effect while antagonists block the neurotransmitter effect (Barron, 2018). There are gradients of how medications act creating a spectrum of influence on receptors. Agonists can occur naturally as neurotransmitters that stimulate receptors. Some medications also act as agonists to stimulate receptors, but medications can stimulate receptors to varying degrees (Stahl, 2013). This creates the spectrum of how medications variably affect neurotransmitters. The medications that stimulate receptors but do so less than full agonists are partial agonists or stabilizers. Antagonists have no activity of their own except to block the activity of the agonists, sometimes antagonists are called silent (Stahl, 2013). At the opposite end of the spectrum from agonists are inverse agonists. These medications block agonists and decrease activity to below the normal baseline level when there is no agonist present (Stahl, 2013).
G Couple proteins and Ion gated channels
Ion gated channels are proteins that form pores in cell membranes (Inanobe & Kurachi, 2014). These pores are the channels that allow movement across the cell membrane and are controlled by several mechanisms. The pore may open due to the voltage difference across the membrane (Ianonobe & Kurachi, 2014). Ligand-gated channels have a domain extracellular that associates with small chemicals and regulatory proteins (Ianonobe & Kurachi, 2014). A domain is a protein that has its own stable structure (Genscript, 2018). Ion channels gated by ligands can be opened or closed by a neurotransmitter that is specific to a ligand binding and causing a very short, brief open active state that occurs in milliseconds (Inanobe & Kurachi, 2014). The ligand-gated channels can also be opened when metabotropic receptors that have G protein-coupled receptors are stimulated by G protein signaling (Inanobe & Kurachi, 2014). The G protein-coupled ion gated open response is slower and is longer lived than the neurotransmitter ion channel opening (Ianonobe & Kurachi, 2014). In summary, an ion gated channel is a throughway to the cell and this throughway is stimulated to be opened or closed by various mechanisms. One of the ways the ion gated channel is stimulated to open is through G couple proteins.