[Gender differences in development of exploratory activity in rats]

The dynamics of exploratory activity in male and female Wistar rats before weaning and over the course of puberty was investigated. Behavior of animals was examined on the 18th, 35th, and 50th postnatal days in a modified light-dark test and on the 24th postnatal day in an open-field test. It was found that exploratory activity of males considerably changed over the course of puberty period. From the 18th to 35th postnatal days, the number of animals exploring a light compartment increased. From the 35th to 50th postnatal days, the duration of the light compartment investigation increased. The only change in exploratory activity of female rats consisted in an increase in the number of transitions between the light and dark compartments from 35th to 50th postnatal days. The results suggest different mechanisms of exploratory behavior development in male and female rats.