Department of Comparative Biosciences, University of Illinois at Urbana-Champaign, 2001 S. Lincoln Avenue, Urbana, IL 61802, USA.
Neurotoxicol Teratol. 2011 May-Jun;33(3):405-14. doi: 10.1016/j.ntt.2011.01.003. Epub 2011 Jan 28.
Estrogens have been shown to have a strong influence on such cognitive domains as spatial memory, response learning, and several tasks of executive function, including both working memory and attention. However, the effects of estrogens on inhibitory control and timing behavior, both important aspects of executive function, have received relatively little attention. We examined the effects of estradiol on inhibitory control and timing behavior using a differential reinforcement of low rates of responding (DRL) task. Ovariectomized young (3 month), middle-aged (12 month), and old (18 month) Long-Evans rats were implanted with Silastic implants containing 0, 5 or 10% 17β-estradiol in cholesterol vehicle and were tested on a DRL task requiring them to wait 15s between lever presses to receive a food reinforcer. The ratio of reinforced to non-reinforced lever presses did not differ across age in the cholesterol vehicle group. Conversely, 17β-estradiol impaired learning of the DRL task in young and middle-aged rats, but the learning of old rats was not impaired relative to vehicle controls following either 5% or 10% 17β-estradiol treatment. Overall, old rats also made fewer lever presses than both the young and middle-aged rats. These results provide new evidence that estrogens impair inhibitory control, an important aspect of self regulation, and add to existing evidence that estrogens differentially affect cognition at different ages.
雌激素对空间记忆、反应学习和几种执行功能任务（包括工作记忆和注意力）有强烈影响。然而，雌激素对抑制控制和时间行为的影响，这是执行功能的两个重要方面，却受到相对较少的关注。我们使用差异强化低反应率（DRL）任务来研究雌二醇对抑制控制和时间行为的影响。去卵巢的年轻（3 个月）、中年（12 个月）和老年（18 个月）长耳兔被植入含有 0、5 或 10% 17β-雌二醇的硅橡胶植入物，并用胆固醇载体进行测试，在需要等待 15 秒才能按下杠杆以获得食物奖励的 DRL 任务上进行测试。在胆固醇载体组中，年龄与比率之间没有差异。相反，17β-雌二醇在年轻和中年大鼠中损害了 DRL 任务的学习，但与载体对照组相比，5%或 10% 17β-雌二醇处理后，老年大鼠的学习并未受损。总的来说，老年大鼠的按压次数也比年轻和中年大鼠少。这些结果提供了新的证据，表明雌激素会损害抑制控制，这是自我调节的一个重要方面，并增加了现有证据，即雌激素在不同年龄以不同的方式影响认知。
