Department of Anatomy and Neurobiology, College of Medicine, University of Kentucky, Lexington, KY 40506, USA.
Neuroimage. 2012 Feb 1;59(3):2923-31. doi: 10.1016/j.neuroimage.2011.09.067. Epub 2011 Oct 1.
Working memory is a cognitive function that is affected by aging and disease. To better understand the neural substrates for working memory, the present study examined the influence of estradiol on working memory using functional magnetic resonance imaging. Pre-menopausal women were tested on a verbal n-back task during the early (EF) and late follicular (LF) phases of the menstrual cycle. Although brain activation patterns were similar across the two phases, the most striking pattern that emerged was that estradiol had different associations with the two hemispheres. Increased activation in left frontal circuitry in the LF phase was associated with increased estradiol levels and decrements in working memory performance. In contrast, increased activation in right hemisphere regions in the LF phase was associated with improved task performance. The present study showed that better performance in the LF than the EF phase was associated with a pattern of reduced recruitment of the left-hemisphere and increased recruitment of the right-hemisphere in the LF compared to EF phase. We speculate that estradiol interferes with left-hemisphere working-memory processing in the LF phase, but that recruitment of the right hemisphere can compensate for left-hemisphere interference. This may be related to the proposal that estradiol can reduce cerebral asymmetries by modulating transcallosal communication (Hausmann, 2005).
工作记忆是一种认知功能，会受到衰老和疾病的影响。为了更好地理解工作记忆的神经基础，本研究使用功能磁共振成像来研究雌二醇对工作记忆的影响。在月经周期的早期（EF 期）和晚期卵泡期（LF 期），对绝经前女性进行言语 n-back 任务测试。尽管在两个阶段的大脑激活模式相似，但最引人注目的模式是，雌二醇与两个半球的关联不同。在 LF 期，左额皮质电路的激活增加与雌二醇水平的增加和工作记忆表现的下降有关。相比之下，在 LF 期，右半球区域的激活增加与任务表现的提高有关。本研究表明，与 EF 期相比，LF 期的表现更好，这与 LF 期与 EF 期相比，左半球的招募减少，右半球的招募增加有关。我们推测，在 LF 期，雌二醇会干扰左半球的工作记忆处理，但右半球的募集可以补偿左半球的干扰。这可能与雌二醇通过调节胼胝体通讯来减少大脑不对称性的观点有关（Hausmann，2005）。
