MEMORY MODULATION ACROSS NEURAL SYSTEMS - INTRAAMYGDALA GLUCOSE REVERSES DEFICITS CAUSED BY INTRASEPTAL MORPHINE ON A SPATIAL TASK BUT NOT ON AN AVERSIVE TASK

Based largely on dissociations of the effects of different lesions on learning and memory, memories for different attributes appear to be or ganized in independent neural systems, Results obtained with direct in jections of drugs into one brain region at a time support a similar co nclusion, The present experiments investigated the effects of simultan eous pharmacological manipulation of two neural systems, the amygdala and the septohippocampal system, to examine possible interactions of m emory modulation across systems. Morphine injected into the medial sep tum impaired memory both for avoidance training and during spontaneous alternation. When glucose was concomitantly administered to the amygd ala, glucose reversed the morphine-induced deficits in memory during a lternation but not for avoidance training, These results suggest that the amygdala is involved in modulation of spatial memory processes and that direct injections of memory-modulating drugs into the amygdala d o not always modulate memory for aversive events. These findings are c ontrary to predictions from the findings of lesion studies and of stud ies using direct injections of drugs into single brain areas. Thus, th e independence of neural systems responsible for processing different classes of memory is less clear than implied by studies using lesions or injections of drugs into single brain areas.