"سکس، مواد مخدر و مغز": تعامل بین مواد مخدر و رفتار جنسی در موش ماده

Preclinical and clinical research investigating female sexual motivation has lagged behind research on male sexual function. The present review summarizes recent advances in our understanding of the specific roles of various brain areas, as well as our understanding of the role of dopaminergic neurotransmission in sexual motivation of the female rat. A number of behavioral paradigms that can be used to thoroughly evaluate sexual behavior in the female rat are first discussed. Although traditional assessment of the reflexive, lordosis posture has been useful in understanding the neuroanatomical and neurochemical systems that contribute to copulatory behavior, the additional behavioral paradigms described in this review have helped us expand our understanding of appetitive and consumatory behavioral patterns that better assess sexual motivation – the equivalent of “desire” in humans. A summary of numerous lesion studies indicates that different areas of the brain, including forebrain and midbrain structures, work together to produce the complex repertoire of female sexual behavior. In addition, by investigating the effects of commonly addictive drugs, we are beginning to elucidate the role of dopaminergic neurotransmission in female sexual motivation. Consequently, research in this area may contribute to meaningful advances in the treatment of human female sexual dysfunction.

The phrase “SEX, DRUGS and ROCK-N-ROLL” represents more than just a flashback to the attitudes of the 1960s. Instead, it epitomizes the commonly held belief that people often equate feelings elicited by sex, drugs and music. It may not be a coincidence that people often describe the experiences that they have with drugs of abuse (e.g., heroin) in sexual terms (e.g., “orgasmic”). Even dating back to Heath's famous studies of electrical brain stimulation in people with severe depression (Bishop et al., 1963), one patient who could voluntarily deliver electrical stimulation to her medial forebrain bundle was video taped calling the button that delivered stimulation – “the sexy button” (Ellis, 1999). The early studies investigating the neural mechanisms underlying the hedonia produced by drugs of abuse led people to conclude that drugs use or “hijack” the neural circuits that animals have to make the basic necessities of survival (food, water and sex) reinforcing ( Kelley and Berridge, 2002). However, much of the research investigating the neural systems underlying the relationship between drugs of abuse and natural reinforcers has focused on male sexual experience. Nevertheless, we are beginning to see advances in our understanding of female sexual motivation using a variety of different animal models. Although female rodent sexual behavior differs substantially from female human sexual behavior, the progress made has been useful in guiding clinical trials that test pharmacological treatments for sexual dysfunction (Pfaus, 2006). In addition, basic research in animal models of sexual motivation has also been useful to our study of drug addiction. The brain has evolved to respond to natural rewards, but drugs of abuse also act on these very same circuits (Kelley and Berridge, 2002). Studies of the interactions between drug rewards and natural rewards have led us to a better understanding of motivation in general. Moreover, such studies can illustrate how drugs of abuse can be disruptive to motivation for natural rewards like sex (Pfaus and Gorzalka, 1987). Because of the recent emphasis on the study of female sexual motivation, the neurochemical and neuroanatomical systems that control all aspects of female sexual behavior are beginning to be elucidated. By using a variety of behavioral paradigms, we hope that basic research will continue to guide future clinical research on treatments for sexual dysfunction, as well as treatments for side effects produced by prescription (e.g., anti-depressants, analgesics) and illicit drug use (e.g., heroin) in women. The goal of this review is threefold: 1) to describe paradigms that are useful in assessing sexual motivation in female rats; 2) to describe the progress made in the search for the neuroanatomical systems underlying female sexual behavior; and 3) to discuss what we have learned from studying the interactions between drugs of abuse and female sexual behavior.