The influence of vibrissae removal on copulatory behaviour in male rats.

The influence of vibrissae removal on copulatory behaviour was tested in both sexually naive and experienced male rats. The experiment consisted of 3 experimental and 3 control sessions. In some sexually naive rats, the removal of the vibrissae caused absence of copulatory behaviour during the first or all 3 experimental sessions, while in other ones this procedure remained without any apparent influence on copulatory behaviour. Three weeks later, after vibrissae have regrown, all of these rats displayed the copulatory behaviour. However, after the regrowth of the vibrissae, in rats with previously impaired copulatory behaviour a shortening of postejaculatory intervals was observed, while in rats with unaffected copulatory behaviour no such differences were observed. In contrast to observations in the sexually naive rats, in the sexually experienced ones removal of vibrissae led to the activation of copulatory behaviour, manifested by shortening of ejaculation latencies and mean interintromission intervals and an increase in hit rate.