| Summary: | 碩士 === 國立成功大學 === 心理學系認知科學碩士班 === 102 === Absence epilepsy, which is characterized by spike-wave discharges (SWDs), is often accompanied by a brief loss of consciousness and behavior impairment. This behavioral impairment during the occurrence of an SWD is influenced by the complexity or difficulty of a cognitive task. Animal models of absence epilepsy display abnormal immobile behavior accompanied by SWDs. The performance of learned conditioning paradigms in response to SWDs has great differences in previous studies. There is largely unknown about the learning progress during SWDs. The present study used the side of face stimulation as a conditioning stimulus to pair the location of a food pellet in a T maze in rats with spontaneous SWDs. The performance of learning progress and recognition session during the situations of normal brain wave (noSWD) and SWDs was assessed. First, four intensities (i.e., motor threshold, 1.2motor threshold, 0.6 mA, 1 mA) were used to stimulate face muscles. Two kinds of low-intensity stimulations had little effect on SWDs, but the other two kinds of stimulations significantly stopped SWD progression. Amplitudes and latencies of the cortical somatosensory evoked potentials (SEPs) elicited by two kinds of low-intensity stimulations were significant difference during SWDs compared to those of noSWD. However, SEPs in response to the other two kinds of high-intensity stimulations were no difference between the noSWD and SWD conditions. Second, the side of face stimulated by the current of a 1.2motor threshold was a conditioning stimulus to pair with the location of a food pellet in the multiple phases of a reversal learning task. The accuracy showed significantly progressive increase during noSWD but no change during SWDs. Reaction time showed significantly progressive reduction in both conditions. In the relearned phase of the reversal learning task, accuracy showed significantly progressive increase during noSWD. However, the performance progressively became a random selection during SWDs. In the recognition session, well-trained rats under the noSWD condition showed ~100% of accuracy in either noSWD or SWD situations. In those trained under SWDs, the recognition accuracy was ~50% in both conditions. Third, memory acquired in the reversal leaning task was extinct during SWDs. Results of the present study indicate that SWDs and SEPs are affected by different stimulation intensities. SWDs modulate learning ability and memory, but have no effect on the retrieval of a memory.
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