Abstract
Two experiments were conducted to test whether a limbic seizure has any effect on memory consolidation. Cats were trained shuttle-box avoidance in Experiment I and figural discrimination in Experiment II. Animals of the experimental group received a limbic seizure produced by hippocampal electrical stimulation (Fig. 1).
In Experiment I, shuttle-box avoidance, animals were given five trials per day for eight days. Animals could avoid the grid shock if they moved toward the other side of the apparatus within five seconds after the flash of light was exposed as CS. Every trial was followed by seizure in the experimental group, one minute after the response.
Results of Experiment I showed that the experimental group could learn the avoidance response as well as the control group (Fig. 2 & 3). No significant differences were found between learning trials required to reach the criterion (Table 1 & 2). It was also shown that the established avoidance response in the limbic seizure period was disrupted when the seizure pattern was propagated to cortical regions. Nevertheless, it was demonstrated that the avoidance response was retained when the training was continued without seizure (Fig. 4).
In Experiment II, animals were trained to discriminate figures (Fig. 6) by the Y-shape apparatus (Fig. 5). Training was given in massed trials; fifteen trials per day in series 1 and five trials per day in series 2. The subjects followed by seizure in series 1a (or 2a) served as controls for those without seizure in series 1b (or 2b), and vice versa.
No difference was found between subjects with seizure and subjects without seizure in the amount of trials needed to master the problem (Table 3 & 4).
From the results obtained in these experiments, it was shown that a limbic seizure produced one minute after the training trial did not retard the memory consolidation.
