Recent research indicated that a particular nuclear group, the medial nucleus of the amygdala, was implicated in memory disruption by electrical stimulation of the brain (ESB) if unilateral, low level, sub seizure ESB was employed. Surprising anatomical specificity for memory disruption by ESB within the ventral midbrain tegmentum is reported. 90 male albino rats were implanted with bipolar electrodes aimed at the region of the substantia nigra. Following 5-7 days operative recovery, animals were trained to remain on a platform to avoid aversive foot shock ('one trial, passive avoidance'). ESB was delivered throughout the training trial only when the animal was on the platform so that no interaction between foot shock and ESB existed. After remaining on the platform for a 2 min learning criterion, a 3 min retention test was given 24 hr later. There was no difference among groups in original learning. There was no difference among unimplanted controls (N=28), implanted unstimulated controls (N=11), and ESB animals in medial lemniscus (N=17), red nucleus (N=9), brainstem (N=24) and substantia nigra, pars reticulata (N=12). The mean retention latency for these groups ranged between 150-180 sec. In contrast, substantia nigra, pars compacta (SNC) ESB animals showed obvious disruption with a mean retention latency of 42.2 sec. In another experiment post trial stimulation was equally effective.
|Original language||English (US)|
|Number of pages||1|
|Issue number||3 (I)|
|State||Published - Jan 1 1973|
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