Physiological and Behavioral Analysis of Raphe Unit Activity

Abstract

The psychological and behavioral effects of many psychoactive drugs are known to be mediated by an action upon neurochemically-identifiable sets of neurons within the CNS, such as those that contain norepinephrine, dopamine, or serotonin. It is, therefore, appropriate to devote a chapter in the Handbook of Psychopharmacology to an examination of the behavioral and physiological correlates of the activity of these systems. In the present chapter, we undertake to do this at a basic level of analysis, that of the single unit, for serotonergic (serotonin-containing) neurons within the CNS. Such neurons are defined as those that synthesize and utilize serotonin for interneuronal communication, by means of its release from presynaptic sites in either axons or dendrites. For the sake of completeness, however, it should also be noted that such neurons may use serotonin for intraneuronal communication, i.e., axon collateral auto-inhibition, and for communicating with nonneuronal tissue such as blood vessels, the ventricular wall, and the choroid plexus (Moore, 1981).