HORMONAL INFLUENCES ON COGNITION

各种研究表明，雌激素可以促进雌性动物和低雌激素水平的人类的记忆。此外，雌激素还可能延缓或预防阿尔茨海默病的发病，并改善患有该病的妇女的认知能力。实验将以年轻和年老的大鼠为模型，通过空间记忆任务——物体识别来检验性腺激素对记忆的影响。首先，将确定雌激素与增强记忆之间的剂量-反应关系。黄体酮与雌激素同时服用是否会改变雌激素对记忆的增强作用将被测试。然后测试性激素对记忆可能的持久影响，即，在停药几个月后，是否单独使用慢性雌激素或与黄体酮一起使用会增强记忆。这些激素治疗对gaba能和单胺能神经传递在涉及记忆功能的大脑区域的影响将通过神经化学技术测量。记忆的改变是否发生在发情周期和慢性卵巢切除术后将被确定，并将显示激素是发挥短期作用还是长期的营养作用。因此，提出的实验将表征性腺激素和记忆功能之间的基本关系。这些研究不仅提供了有关激素作用和激素对记忆影响的神经基础的基本信息，而且对衰老和阿尔茨海默病也有重要的健康意义。雌激素和黄体酮联合治疗是绝经后妇女的首选治疗方法，但对黄体酮对记忆的影响知之甚少。此外，如果绝经后激素替代疗法可以将痴呆症的发病延迟5年，预计痴呆症的发病率将下降50%。最后，如果仅仅几年的替代就能对记忆丧失或发生阿尔茨海默病有同样的好处，那么雌激素副作用的风险就可以大大降低。

A variety of studies show that estrogen may promote memory in females, both animal and human with low estrogen levels. Moreover, estrogen may also delay or prevent the onset of Alzheimer's Disease and improve cognition in women with the disease. Using young and aged rats as models, experiments will examine effects of gonadal hormones on memory using a spatial memory task, object recognition. First, the dose- response relationship between estrogen and enhanced memory will be determined.. Whether concurrent administration of progesterone with estrogen alters the enhancing effects of estrogen on memory will be tested. Then possible enduring effects of gonadal hormones on memory will be tested, i.e., whether chronic estrogen alone or with progesterone enhances memory months after discontinuation. Effects of these hormone treatments on GABAergic and monoaminergic neurotransmission in brain areas involved in memory function will be measured by neurochemical techniques. Whether alterations in memory occur over the estrus cycle and after chronic ovariectomy will be determined and will show whether hormones exert short term effects or long term, trophic effects. Thus, proposed experiments will characterized fundamental relationships between gonadal hormones and memory function. While important for providing basic information concerning hormone actions and the neural bases for hormonal effects on memory, the studies also have significant health implications for aging and Alzheimer's disease. Concurrent estrogen and progesterone therapy is the treatment of choice for post menopausal women, but little is known about the effects of progesterone on memory. In addition, if post-menopausal hormone replacement therapy can delay dementia onset by 5 years, the incidence of dementia has been projected to decreased by 50%. Finally, if only a few years of replacement can be given with the same benefits on memory loss or in developing AD, then the risk of side effects of estrogen can be greatly minimized.