Wallin-Miller Kathryn G, Chesley Jordyn, Castrillon Juliana, Wood Ruth I
Neuroscience Graduate Program, University of Southern California, Los Angeles, CA 90033, USA.
Department of Cell and Neurobiology, Keck School of Medicine of the University of Southern California, Los Angeles, CA 90033, USA.
Drug Alcohol Depend. 2017 May 1;174:137-144. doi: 10.1016/j.drugalcdep.2017.01.023. Epub 2017 Mar 7.
Ethanol (EtOH) intake correlates with increased risk-taking, and sex differences exist in both EtOH use and risk-taking in humans and rats. However, the interaction of sex and gonadal hormones to affect risk-taking under the influence of EtOH has not been determined. This was the focus of the current study.
Adult Long-Evans rats (n=18 males and females) were gonadectomized and received hormone replacement at physiologic levels or blank implants (n=7-9/group). Risk-taking was assessed with probability discounting, requiring rats to choose between a small/certain reward and a large/uncertain reward delivered with decreasing probability throughout each daily session. Before testing, rats received saline or EtOH (0.5 or 1.0g/kg) ip.
In males, EtOH increased preference for the large/uncertain reward lever (F=10.462, p<0.05). However, there was no effect of EtOH on lever preference in females (F=0.914, p>0.05). At baseline, ORCHX+T males showed a greater preference for the large/uncertain reward lever then ORCHX males (F=13.805, p<0.05). In females only, EtOH decreased choice latency relative to baseline (F=7.25, p<0.05). EtOH decreased loss sensitivity in both sexes, with all rats exhibiting decreased lose-shift ratios (males: F=5.10, p<0.05; females F=4.37, p<0.05).
These results show that EtOH, sex, and hormones interact to influence decision making. EtOH increases risk taking in males, but not in females. However, EtOH selectively decreases choice latency in females, and decreases loss sensitivity in both sexes. These findings are relevant to understanding human behavior, particularly in adolescents who experience increased hormone levels and often drink EtOH and engage in risky behavior.
乙醇（EtOH）摄入与冒险行为增加相关，在人类和大鼠的乙醇使用及冒险行为中均存在性别差异。然而，性别和性腺激素在乙醇影响下对冒险行为的相互作用尚未确定。这是本研究的重点。
成年Long-Evans大鼠（n = 18只雄性和雌性）接受性腺切除，并接受生理水平的激素替代或空白植入物（n = 7 - 9只/组）。通过概率折扣评估冒险行为，要求大鼠在每次每日实验中，在一个小的/确定的奖励和一个大的/不确定的奖励之间进行选择，大的/不确定的奖励出现概率逐渐降低。在测试前，大鼠腹腔注射生理盐水或EtOH（0.5或1.0 g/kg）。
在雄性中，EtOH增加了对大的/不确定奖励杠杆的偏好（F = 10.462，p < 0.05）。然而，EtOH对雌性的杠杆偏好没有影响（F = 0.914，p > 0.05）。在基线时，去势+睾酮（ORCHX+T）雄性比去势（ORCHX）雄性对大的/不确定奖励杠杆表现出更大的偏好（F = 13.805，p < 0.05）。仅在雌性中，EtOH相对于基线降低了选择潜伏期（F = 7.25，p < 0.05）。EtOH降低了两性的损失敏感性，所有大鼠的损失转移率均降低（雄性：F = 5.10，p < 0.05；雌性：F = 4.37，p < 0.05）。
这些结果表明，EtOH、性别和激素相互作用影响决策。EtOH增加雄性的冒险行为，但不增加雌性的冒险行为。然而，EtOH选择性地降低雌性的选择潜伏期，并降低两性的损失敏感性。这些发现有助于理解人类行为，特别是在激素水平升高、经常饮用EtOH并从事危险行为的青少年中。
