DOPAMINE TRANSMISSION INCREASES IN THE NUCLEUS-ACCUMBENS OF MALE-RATSDURING THEIR 1ST EXPOSURE TO SEXUALLY RECEPTIVE FEMALE RATS

In vivo microdialysis was used to monitor extracellular concentrations of dopamine (DA), and its metabolites dihydroxyphenylacetic acid (DOP AC) and homovanillic acid (HVA), in the nucleus accumbens of sexually naive male rats during their first exposure to sexually receptive or n onreceptive females. DA, DOPAC, and HVA increased progressively and si gnificantly in males that copulated to ejaculation with receptive fema les. In contrast, DA, DOPAC, and HVA did not increase significantly in males exposed to non-receptive females, despite several attempts by t hese males to mount the non-receptive females. These results indicate that DA is released unconditionally in the nucleus accumbens of male r ats by exposure to sexually receptive female rats, and that copulation with intromission, but not mounting alone, leads to further increases in DA release.