[Effects of procaine and apomorphine injected into the ventral tegmental area on self-stimulation of the nucleus accubens (author's transl)].

In the present study, microinjection of procaine and apomorphine were made into the ventral tegmental area (VTA) during self-stimulation of the nucleus accumbens (NAS). By blocking the VTA input to NAS with procaine, it should be possible to influence self-stimulation of the NAS. In addition, since it has been suggested that dendrites of VTA dopaminergic neurons contain dopamine "autoreceptors", the effect of microjections of apomorphine a dopamine agonist, into the VTA on self-stimulation of the nucleus accumbens was also investigated. Reseult obtained were as follow: The injection of procaine to VTA reduced self-stimulation of the ipsilateral NAS and the administration of apomorphine to the VTA significantly attenuated self-stimulation of the ipsilateral NAS completely suppressing it for 3--4 min. Self-stimulation of NAS has been suggested to activate fiber projection of mesolimbic dopamineric neurons (A10) from VTA.