FACILITATION OF AVOIDANCE LEARNING BY POSTTRIAL HIPPOCAMPAL ELECTRICAL STIMULATION

To examine the possibility that low-intensity posttrial brain stimulation might enhance learning, 63 male albino rats were stimulated in the hippocampus (HPC) after each trial in a discriminated lever-press avoidance situation. Intracranial stimuli were 30 MUa., AC or DC, and 200 MUa. AC, 60 cps for 3 sec., presented 10 sec. after every avoidance or escape response. 30-microampere HPC-stimulated Ss learned significantly faster than unstimulated controls and frontal-region-stimulated Ss. Removal of stimulation after attainment of an 85% avoidance criterion did not produce a performance decrement, but 1 mg/kg of atropine sulfate prevented the enhancement effects of HPC stimulation. The conclusion is that HPC stimulation can enhance avoidance acquisition, perhaps by facilitating neural consolidation processes resulting from or mediated by increased acetylcholine release. (15 ref.) (PsycINFO Database Record (c) 2006 APA, all rights reserved). © 1969 American Psychological Association.