The purpose of this research is to examine the neurochemical and behavioral effects produced by administration of various Beta-carboline drugs in mice. &-Methoxy-1,2,3,4-tetrahydro-Beta-carboline (6-MeO-THBC) has been reported to specifically elevate brain serotonin, and other Beta-carbolines, such as harmaline and harmine, have been reported to affect serotonin as well as the other biogenic amines norepinephrine and dopamine. In view of reports in the literature suggesting a relationship between biogenic amines and behavior, 6-MeO-THBC and other Beta-carbolines will be studied for their neurochemical effects on brain biogenic amine concentrations and synthesis, subcellular distribution and uptake, as well as for their effects on monoamine oxidase. An attempt will be made to correlate these neurochemical effects with effects of the drugs on behaviors such as audiogenic seizures, learning and memory, activity, reactivity, operant behavior, and on body temperature and plasma corticosterone. It is hoped that structure-function relationships will be determined between the drugs and their neurochemical and behavioral effects.