Ethanol Effects on Cortical EEG Correlation and Sexual Behavior in Male Rats

Abstract

Ethanol affects sexual behavior drastically, as much as its execution as well as its motivation. Ethanol is a central nervous system depressant and the prefrontal cortex (PFC) is one of the cortical areas most sensitive to its effects. This prefrontal area participates in the modulation of the cognitive control, and furthermore, by mean of connections with the parietal cortex (PC) plays an important role in the processing of sexually relevant stimuli. Considering that it has been reported that the ethanol affects the proper functioning of these cortical areas, particularly decreasing the degree of electroencephalographic (EEG) coupling or correlation between them, the aim of this study was to characterize the effect of a low dose of ethanol on EEG correlation, as well determining if this effect is associated with impaired sexual behavior in male rats. Nine male rats unilaterally implanted were simultaneously recorded the EEG from the PFC and PC to calculate the degree of EEG synchronization (correlation, r) between both cortices during the first 40 minutes post administration of 0.75 g/kg of ethanol. At the end of the EEG recording, the males were submitted to copulatory behavior with a receptive female rat. The ethanol administration was associated with a decreased intrahemispheric correlation of the fast bands between PFC and PC, as well as with an increased mount and intromission latency. This data showed that ethanol in moderate doses decreased the coupling degree between cortices. It is likely that this functional disconnection between the PFC and PC after the ethanol administration could be associated with the difficulty in discriminating incentive value of the sexual stimuli so that decreased the sexual motivation but not the performance of the copulatory parameters in the male rat.