CHARACTERISTIC FREQUENCY BANDS OF THE CORTICO-FRONTAL EEG DURING THE SEXUAL INTERACTION OF THE MALE-RAT AS A RESULT OF FACTORIAL ANALYSIS

The electrocorticogram (ECoG) from the prefrontal cortex was simultane ously recorded with the accelerometric signals of pelvic thrusting per formed by male rats during sexual behavior. The changes in the prefron tal ECoG were precisely correlated in time with well defined elements of male rat copulation. Principal component analysis allowed to identi fy three distinct bands of frequencies in the frontal ECoG: the absolu te power (AP) of the 4-16 Hz band was increased in the 500-ms periods before, during, and after the execution of pelvic thrusting in mount, intromission and ejaculation responses; the AP of the 18-24 Hz band wa s selectively increased during the execution of pelvic thrusting at th e three copulatory responses, whereas the AP of the 26-32 Hz band was increased only during the pelvic movements of mount and intromission r esponses. These results show that the electroencephalographic activity of the prefrontal cortex of the male rd is related to the performance of sexual behavior, supporting the concept that this cortical area is involved in the organization of sequential behaviors. as sexual behav ior. (C) Elsevier, Paris.