Effect of Age in Sexual Behavior of Sleep Deprived Rats after Cocaine Administration

Introduction: It has been suggested that paradoxical sleep deprivation (PSD) could sensitize dopaminergic systems, probably by inducing supersensitivity of the post synaptic receptor (TUFIK et al., 1978). The mesolimbic dopamine (DA) system, composed of DAergic neurons in the ventral tegmental area and their projections to the nucleus accumbens and other forebrain structures, has been implicated in the reinforcing and locomotor-activating properties of cocaine (HOGER et al., 1999). In 2000, ANDERSEN et al., showed that acute cocaine administration elicited sexual behavior in young PSD rats. It is known that there is a decline in sexual arousal and copulatory activity in male rats with advancing age, as well as significant changes in various sleep parameters. Thus, the objective of the present study was to examine the behaviors of penile erection and ejaculation in young and old-age rats submitted to PSD after cocaine administration. Methods: Young (3 months) and middle-age (22 months) male rats were PSD for 96 hours by the modified multiple platform methods or stayed in their cages (control group-CTRL). At the end of this period, the animals received an i.p. injection of cocaine (15 mg/kg) and the erections and ejaculations were assessed for 60 minutes. Results: The cocaine-PSD study revealed a significant difference between the 3monthsPSD and the three other groups with regard to sexual behavior. The young PSD rats had the greatest number of erection and ejaculation. Among the old-age rats, the PSD group only had erection and sexual behavior was absent in the 22 months control group.