Hippocampal rhythmical slow activity during instrumental responses with sexual reinforcement in male rats.

The hippocampal EEG activity was recorded in male rats during the response-contingent reinforcement of a female. The instrumental response was a bar-pressing on a fixed-ratio-10 reinforcement schedule. The frequency of bar-pressing tends to increase during the succeeding copulatory series. The similar phenomenon was observed in the frequency of the hippocampal slow activity (RSA) accompanying the bar-pressing and the pursuit of the female. This tendency was most conspicuously present during the first copulatory series but became less evident during the following ones.