Locklear M N, Kritzer M F
Graduate Program in Neuroscience, Stony Brook University, Stony Brook, NY, USA; Dept. of Neurobiology and Behavior, Stony Brook University, Stony Brook, NY, USA.
Dept. of Neurobiology and Behavior, Stony Brook University, Stony Brook, NY, USA.
Horm Behav. 2014 Jul;66(2):298-308. doi: 10.1016/j.yhbeh.2014.06.006. Epub 2014 Jun 14.
Although sex differences and hormone effects on spatial cognition are observed in humans and animals, consensus has not been reached regarding exact impact on spatial working or reference memory. Recent studies in rats suggest that stress and/or reward, which are often different in tasks used to assess spatial cognition, can contribute to the inconsistencies in the literature. To minimize the impact of these sex- and sex hormone-sensitive factors, we used the Barnes maze to compare spatial working memory, spatial reference memory and spatial learning strategy in adult male, female, gonadectomized (GDX) male, and GDX male rats supplemented with 17β-estradiol (E) or testosterone propionate (TP). Rats received four acquisition trials, four trials 24h later, and a single retention trial one week after. Males and females acquired the task during the first four trials and retained the task thereafter. In contrast, GDX rats took longer to acquire the task and showed retention deficits at 1week. All deficits were attenuated similarly by TP and E. Assessment of search patterns also showed that strategies in the males transitioned from random to spatially focused and eventually direct approaches to the goal. However, this transition was faster in control and GDX-TP than in GDX and GDX-E rats. In contrast, the females almost invariantly followed the maze edge in thigmotactic, serial searches. Thus, while Barnes maze reveals activational, in part estrogenic effects on spatial cognition in males, its amenability to animals' use of multiple strategies may limit its ability to resolve mnemonic differences across sex.
尽管在人类和动物中都观察到了性别差异以及激素对空间认知的影响，但对于其对空间工作记忆或参考记忆的确切影响尚未达成共识。最近对大鼠的研究表明，压力和/或奖励（在用于评估空间认知的任务中往往有所不同）可能导致文献中的不一致。为了尽量减少这些对性别和性激素敏感因素的影响，我们使用巴恩斯迷宫比较成年雄性、雌性、去势（GDX）雄性以及补充了17β-雌二醇（E）或丙酸睾酮（TP）的GDX雄性大鼠的空间工作记忆、空间参考记忆和空间学习策略。大鼠接受了四次获取试验，24小时后进行四次试验，一周后进行一次保留试验。雄性和雌性在最初的四次试验中学会了任务，并在此后保持了该任务。相比之下，GDX大鼠学习任务花费的时间更长，并且在1周时表现出保留缺陷。TP和E对所有缺陷的缓解作用相似。对搜索模式的评估还表明，雄性的策略从随机转变为空间聚焦，最终直接指向目标。然而，对照组和GDX-TP组的这种转变比GDX组和GDX-E组更快。相比之下，雌性在触觉性、串行搜索中几乎始终沿着迷宫边缘。因此，虽然巴恩斯迷宫揭示了对雄性空间认知的激活作用，部分是雌激素的作用，但其对动物使用多种策略的适应性可能会限制其分辨不同性别记忆差异的能力。
