ANIMAL BEHAVIOR MODEL FOR STUDYING CENTRAL SEROTONERGIC SYNAPSES

An animal behavior model for studying the functional activity in central serotonin-mediated synapses was described. It was produced by compounds which either increase synaptic serotonin content or stimulate serotonin receptors, and consisted most conspicuously of tremor, rigidity, reciprocal forepaw treading, Straub tail, hindlimb abduction and lateral head weaving. It had great specificity in reflecting only the activity in the serotonin system. The neuronal substrates that mediate the elaboration of the component signs were localized exclusively in the lower brainstem and spinal cord. Although it was studied most extensively in the rat, a similar response pattern was also seen in a number of different species. It was a useful tool in studying phenomena as diverse as the effect of hypothalamic factors on CNS neurotransmission, the metabolism of serotonin, the action of therapeutic and psychoactive drugs, the pharmacology of central serotonin receptors, the actions of LSD, and the development of denervation supersensitivity in the central serotonin system.