Cummings Jennifer A, Clinton Sarah M, Perry Adam N, Akil Huda, Becker Jill B
Molecular and Behavioral Neuroscience Institute, University of Michigan, 205 Zina Pitcher Place, Ann Arbor, MI 48109, USA.
Behav Neurosci. 2013 Feb;127(1):47-58. doi: 10.1037/a0031528.
High- versus low-novelty exploration predicts a variety of behavioral differences. For example, rats selectively bred for high-novelty exploration (bred-high responders, bHR) exhibit exaggerated aggression, impulsivity, and proclivity to addictive behaviors compared with low-novelty reactive rats (bred-low responders, bLRs), which are characterized by a high anxiety/depressive-like phenotype. Since bHR/bLR rats exhibit differences in dopaminergic circuitry and differential response to rewarding stimuli (i.e., psychostimulants, food), the present study examined whether they also differ in another key hedonic behavior-sex. Thus, adult bHR/bLR males were given five 30-min opportunities to engage in sexual activity with a receptive female. Sexual behavior and motivation were examined and compared between the groups. The bHR/bLR phenotype affected both sexual motivation and behavior, with bLR males demonstrating reduced motivation for sex compared with bHR males (i.e., fewer animals copulated, longer latency to engage in sex). The bHR males required more intromissions at a faster pace per ejaculation than did bLR males. Thus, neurobiological differences that affect motivation for drugs of abuse, aggression, and impulsivity in rats also affect sexual motivation and performance.
高新奇探索与低新奇探索预示着多种行为差异。例如,经过选择性培育以进行高新奇探索的大鼠(高反应性品系,bHR)与低新奇反应性大鼠(低反应性品系,bLRs)相比,表现出过度的攻击性、冲动性和成瘾行为倾向,后者具有高焦虑/抑郁样表型。由于bHR/bLR大鼠在多巴胺能神经回路方面存在差异,且对奖励刺激(即精神兴奋剂、食物)有不同反应,本研究考察了它们在另一关键享乐行为——性行为方面是否也存在差异。因此,给予成年bHR/bLR雄性大鼠五次30分钟的机会与处于接受状态的雌性大鼠进行性活动,并对两组之间的性行为和动机进行了检查和比较。bHR/bLR表型影响了性动机和性行为,与bHR雄性大鼠相比,bLR雄性大鼠表现出更低的性动机(即交配的动物更少,开始性行为的潜伏期更长)。与bLR雄性大鼠相比,bHR雄性大鼠每次射精所需的插入次数更多,速度更快。因此,影响大鼠滥用药物动机、攻击性和冲动性的神经生物学差异也会影响性动机和性行为表现。