ISSN : 1226-9654
We investigated the effects of capsaicin(s.c. 150mg/kg) on the open-field behaviors and the thresholds and latency of nociceptive responses in adult rats. Results are as follows. 1) Capsaicin did not affect open-field behaviors. It hints that capsaicin did not alter the emotionality and motor function of rats. 2) Whereas the threshold of jumping was elevated, those of fore and hind paw licking were not in animals treated with capsaicin. Capsaicin also enhanced hind paw licking latency to thermal stimulus over thershold in hot plate test. These results suggest that capsaicin affects the coping reaction to strong thermal stimulus, but not adaptive reaction to mild stimulus, in adult rats.