[A comparison of the effects of single and chronic microinjections of GABA and picrotoxin into the caudate nucleus on the conditioned reflexes of dogs].

The effects on Pavlovian alimentary conditioned reflexes realization of two methods of intrastriatal microinjections--acute (separate) and long-term (chronic) one--are compared in experiments on dogs. Bilateral acute administration and the first week of chronic injection of 45 mcg of GABA into the caudate nuclei produced in dogs a manifest improvement of parameters of the conditioned differentiation inhibition, but only in the next period of chronic treatment an improvement of the positive Pavlovian alimentary conditioned reflex was obtained. The both ways of picrotoxin treatment impaired conditioned behaviour, and this effect was observed after the end of injection. No withdrawal effects were recorded. The data obtained give ground for discussion of the role of striatal GABAergic system in the positive modulation of adaptive alimentary behaviour. The application of novel psychopharmacological method in experimental and clinical fields of investigation is discussed.