Learning-induced change in neural activity during acquisition and consolidation of a passive avoidance response in the rat.

Time-dependent alterations in neural activity have been established during the acquisition and consolidation of a stepdown passive avoidance paradigm. Change in neural activity was established by administering a glucose analogue, [3H]2-deoxyglucose, 50min prior to sacrifice and estimating perchloric acid soluble counts in nine hand dissected brain regions. Change in [3H]2-deoxyglucose uptake was closely paralleled in both trained and yoked animals for up to 40min following task acquisition however the striatum was the only area to exhibit a task-specific increase in [3H]2-deoxyglucose uptake at 20-30min after training. Longterm changes in neural activity were also apparent as the amygdala and brainstem showed increased [3H]2-deoxyglucose uptake at the 24 h time point. No further paradigm-specific changes were apparent at 48 h. These findings are concluded to suggest that the striatum is involved in the early events of acquiring a passive avoidance response and the amygdala and brainstem during the later events.