Facultad de Psicología, Universidad Nacional Autónoma de México, México D.F. 04510, Mexico.
Behav Brain Res. 2011 Oct 10;224(1):189-94. doi: 10.1016/j.bbr.2011.06.005. Epub 2011 Jun 13.
There is evidence of deterioration of spatial cognition in streptozotocin (STZ)-induced diabetic rats. Here, we evaluate a possible dissociation in the cognitive deficits due to diabetes by examining another crucial aspect of animal cognition: temporal perception. Timing behavior and temporal memory were evaluated in STZ-induced diabetic rats employing two timing tasks: the peak-interval procedure, with its Gap variant, and the interval bisection task. A spatial memory task, rewarded alternation in the T-maze, was also evaluated to explore spatial cognition. The two timing tasks employed coincide in the finding of a normal timing performance in STZ-induced diabetic rats. The peak-interval procedure provided results that suggest that the timing behavior is equally accurate and precise than in control subjects; in the Gap procedure, an equal change in peak time in both groups indicates that temporal working memory is also intact. In the interval bisection task, we analyzed the acquisition of a temporal discrimination and the sensitivity to changes in the duration of the stimulus; no differences were found in either the acquisition process or the sensitivity index. In contrast, in the rewarded alternation task, STZ-induced diabetic rats exhibited a significant deficit in spatial cognition. The cognitive processes involved in timing behavior and temporal memory are not deteriorated as a consequence of diabetes; the cognitive deficits associated to diabetes thus seem to be restricted to the spatial domain.
有证据表明，链脲佐菌素（STZ）诱导的糖尿病大鼠的空间认知能力下降。在这里，我们通过检查动物认知的另一个关键方面来评估由于糖尿病导致的认知缺陷的可能分离：时间感知。使用两种计时任务评估 STZ 诱导的糖尿病大鼠的计时行为和时间记忆：峰间隔程序及其间隙变体，以及间隔二分任务。还评估了 T 迷宫中的奖励交替的空间记忆任务，以探索空间认知。两种计时任务的结果一致，发现 STZ 诱导的糖尿病大鼠的计时表现正常。峰间隔程序提供的结果表明，计时行为与对照组一样准确和精确；在间隙程序中，两组的峰值时间相等变化表明时间工作记忆也完好无损。在间隔二分任务中，我们分析了时间辨别力的获得以及对刺激持续时间变化的敏感性；在获得过程或敏感性指数中均未发现差异。相比之下，在奖励交替任务中，STZ 诱导的糖尿病大鼠在空间认知方面表现出明显的缺陷。与时间行为和时间记忆相关的认知过程没有因糖尿病而恶化；因此，与糖尿病相关的认知缺陷似乎仅限于空间领域。
