Role of neurochemical mechanisms of the caudate nucleus in different models of anxiety in rats

Microinjections of dopamine, apomorphine, and GABA to the dorsal part of the caudate nucleus decreased the level of anxiety in an illuminated platform avoidance task in rats, while sulpiride and picrotoxin increased it. Intrastriatal injection of serotonin, glutamic acid, yohimbine, and phenylephrine reduced anxiety in threatening situation, but not in the illuminated platform avoidance task. It is suggested that emotional states associated with different kinds of stress are realized through diverse neurochemical systems of the caudate nucleus neuronal network.[PUBLICATION ABSTRACT]