Analysis of Striopallidal Interactions in the Control of Avoidance Behavior

The effects of chronic administration of phenamine (15 μg) into the neostriatum and bicucculline (5 μg) in the globus pallidus of rats on the performance of avoidance behavior in a shuttle box were studied. Agents were injected daily for three weeks, and control animals received physiological saline. Activation of the dopaminergic system of the neostriatum compensated for decreases in avoidance behavior due to surgical trauma, increased the intensity of spontaneous activity in the “open field,” and induced motor stereotypy. Administration of bicucculline into the globus pallidus produced sharp worsening of conditioned reflex avoidance behavior throughout the treatment period (spontaneous movement activity showed no significant change), with recovery only occurring two weeks after the last microinjection. Simultaneous treatment with phenamine into the neostriatum and bicucculline into the globus pallidus resulted in compensation for the inhibitory effects of bicucculline. Several phases were observed in behavioral changes, apparently reflecting the dynamics of interactions between the neo- and paleostriatum. The significance of the coordination of intrastriatal functions for the regulatory activity of the basal ganglia is discussed.