Alcohol consumption in male rats increases after sexual interaction
It has been reported that sexual encounters influences not only the subsequent behavior of subjects but also certain physiological states. The purpose of this study was to examine alcohol consumption after different types of sexual interaction in male rats. Male Wis- tar rats were subjected to a process of induction to alcohol so that they would learn to consume a 10% ethanol solution. Afterwards, they were subjected to four different types of sexual interaction: (1) enforced interval copulation (EIC) to ejaculation (group EIC E); (2) en- forced interval copulation up to 3 intromissions (group EIC 3I); (3) ad libitum copulation to ejaculation (group ADC E); and (4) ad libitum copulation up to 3 intromissions (group ADC 3I). Immediately after the sexual interaction, each rat was exposed to two bottles; one containing water, the other a 10% ethanol solution, for a period of 8 minutes. Only the males that reached ejaculation and those that were allowed to copulate ad libitum up to 3 intromissions showed higher alcohol consumption. Considering that sexual behavior activates brain systems that are known to play a role in alcohol intake, such as the dopaminergic and opioidergic systems, it is probable that the activation of these systems brought on by sexual activity could have generated a state of higher motivation to consume alcohol or, alternatively, potentialized its reinforcing properties. These data suggest that alcohol consumption is sensitive to the type of sexual interaction and, hence, to the motivational/arousal state that the male rat experienced prior to exposure to alcohol.