Claflin Dragana Ivkovich, Hennessy Michael B, Jensen Sarah J
Department of Psychology/335 Fawcett, Wright State University, 3640 Colonel Glenn Highway, Dayton, OH 45435, USA.
Physiol Behav. 2005 Jun 2;85(2):159-66. doi: 10.1016/j.physbeh.2005.03.015.
Glucocorticoids administered during development can have lasting consequences on learning performance and brain development. Whereas most studies administer glucocorticoids to the young rat during the so-called stress-hyporesponsiveness period (SHRP), we examined the effects of corticosterone pellets implanted at the conclusion of the SHRP on two forms of eye blink conditioning (EBC). Analysis of blood samples indicated that pellets implanted on Day 15 released the bulk of the corticosterone before Day 21. In tests of EBC beginning on Day 28, corticosterone-treated males, but not females, showed impaired performance in the hippocampally mediated "trace" version of the EBC paradigm. There were no effects of corticosterone on the "delay" version of the task. These results are consistent with earlier findings that the hippocampus is particularly sensitive to elevated glucocorticoid levels. Moreover, the findings suggest that glucocorticoids administered after the SHRP may produce subtle effects on learning performance akin to those that have been reported in children.
发育期间给予糖皮质激素会对学习能力和大脑发育产生持久影响。大多数研究在所谓的应激低反应期（SHRP）给幼鼠施用糖皮质激素，而我们研究了在SHRP结束时植入皮质酮丸剂对两种形式的眨眼条件反射（EBC）的影响。血液样本分析表明，在第15天植入的丸剂在第21天之前释放了大部分皮质酮。在从第28天开始的EBC测试中，接受皮质酮治疗的雄性，但雌性没有，在海马介导的EBC范式的“痕迹”版本中表现受损。皮质酮对任务的“延迟”版本没有影响。这些结果与早期的发现一致，即海马对升高的糖皮质激素水平特别敏感。此外，这些发现表明，在SHRP之后施用糖皮质激素可能会对学习能力产生微妙影响，类似于在儿童中报道的那些影响。
