[Effects of intrahippocampal injection of 6-OHDA on acquisition and retention of avoidance response in rats].

The role of hippocampal noradrenergic and dopaminergic transmission in the acquisition and retention of active conditioned avoidance behavior was investigated in rats by injection of 6-hydroxydopamine (6-OHDA) into dorsal hippocampus. The main results are as follows: (1) After injection of 6-OHDA the contents of dopamine, particularly norepinephrine (P < 0.01) in the hippocampus was decreased significantly. (2) The acquisition of conditioned avoidance behavior was markedly impaired. (3) The facilitating effect of AVP on retention of active conditioned avoidance behavior could be eliminated by prior injection of 6-OHDA bilaterally into hippocampus.