Serotonin Receptors: Serotonin is 5 hydroxytryptamine (5HT). Four families of Serotonin receptors, comprising of 14 subtypes have so far been recognized. Types of Serotonin (5HT) Receptors: 5-HT1 5-HT2 5-HT3 5-HT4-7 Location and effects of 5-HT receptors; 5-HT1 receptors: These are present in brain. most important location is raphe nuclei of brain stem and hippocampus, the anti anxiety drug buprione acts as a partial agonis of 5-HT1A receptor. other locations include substantia nigra basal ganglia cranial blood vessels ( cause contraction) 5HT1 receptors inhibit adenylyl cyclase and cause hyperpolarization of neurons and inhibit transmission. 5-HT2 Receptors: There are three subtypes of 5-HT2 receptors, 5-HT2a, 5-HT2b, 5-HT2c, these receptors are coupled to phospholipase C and act through generation of IP3 and GAG. 5HT2a is the most widely expressed postjunctional 5-HT receptor and located on vascular and viceral smooth muscles, platelets and...