The effect of age on the development of hyperemotionality following bilateral olfactory bulbectomy in rats.

The effect of age on the development of hyperemotionality including muricide induced by either olfactory bulbectomy or isolated housing was studied in rats. In olfactory bulbectomized groups, 13-week-old rats showed the highest score of emotionality and shortest latency in the onset of hyperemotionality and muricide among any other groups of rats. On the other hand, in the groups subjected to isolation, 4-week-old rats showed a higher score of emotionality than 13-week-old rats. These results suggest that the age of the rat at the beginning of experiment is quite important in the induction of hyperemotionality following both olfactory bulbectomy and isolated housing.