INHIBITORY AVOIDANCE IMPAIRMENTS INDUCED BY INTRAAMYGDALA PROPRANOLOLARE REVERSED BY GLUTAMATE BUT NOT GLUCOSE

Both systemic and central injections of glucose can enhance memory. Fo r example, glucose reverses impairments on inhibitory avoidance result ing from intra-amygdala injections of morphine. The present experiment investigated the ability of glucose to reverse memory impairments res ulting from intra-amygdala injections of propranolol, a beta-noradrene rgic antagonist. Pretraining administration of 10 mu g propranolol sig nificantly reduced inhibitory avoidance retention latencies but had no effect on performance in a spontaneous alternation task. Coadministra tion of glucose into the amygdala at 3 doses (1.5, 3.0, and 6.0 mu g) did not reverse the propranolol-induced inhibitory avoidance deficits. However, coadministration of 2.5 mu g of glutamate with the propranol ol did reverse these deficits. The ability of glucose to reverse impai rments following intra-amygdala injections of morphine but not propran olol may reflect the neurotransmitter system or systems through which glucose exerts its effects.