HIPPOCAMPAL SPATIAL REPRESENTATIONS

通常观察到空间能力随着正常的衰老而下降 在人类和老鼠身上。 为了未来的发展， 适当的治疗方法，有必要了解 与年龄有关的大脑组织变化的贡献。 海马 在这方面是一个特别有趣研究结构，因为它 对于获取新的空间信息至关重要， 它似乎特别容易受到年龄相关的病理性 异常 因此，本研究的重点是了解 衰老的生理特性之间的关系 海马结构和大鼠的空间行为。 自从新立科技 海马内的激活被不同的 皮质下传入（其中一些已知经历显著的 随着年龄的变化），这项研究还将研究的可能性， 皮层下输入的年龄相关变化会影响 海马体表示环境的空间方面。 本提案的具体目标是提供一个全面的 评估空间和神经表征的贡献 海马运动对老年大鼠空间表现受损的影响。 这一目标将分两部分来实现：第一， 单个海马神经元的群体将与特定的 行为和空间认知技能的年轻和年老的动物。 还有， 可能的年龄差异因素，如注意空间线索， 考虑与年龄相关的选择准确性变化， 神经生理功能 本提案第2部分将评估 年龄对海马功能皮层下调制的影响 监测选择性和非选择性的行为和生理后果， 可逆性传入阻滞在年轻和老年大鼠执行空间 记忆任务 将检查7个传入结构。 临时 将通过局部麻醉剂的微量注射来实现传入神经阻滞 （丁卡因）或GABA激动剂（蝇蕈醇）进入传入核。 使用 最近开发的注射记录程序， 研究，直接的行为和生理后果， 选择性去传入神经以及恢复到基线条件。 将被观察。 传入激活效应将由当地 注射谷氨酸或卡巴胆碱。 总之，这些结果应该 提供了重要的洞察可能的年龄变化的神经 表示对于准确的空间行为至关重要的信息。

Spatial abilities are often observed to decline as a result of normal aging in both humans and rats. In the interest of the future development of appropriate therapeutic treatments, it is necessary to understand the contribution of age-related changes in brain organization. The hippocampus is a particularly interesting structure for study in this regard because it is considered critical for the acquisition of new spatial information, and it appears particularly susceptible to age-associated pathological abnormalities. Thus, the prim,dry focus of this research is to understand the relationship between physiological properties of a senescent hippocampal formation and spatial performance in rats. Since synaptic activation within hippocampus is extensively modulated by different subcortical afferents (some of which are known to undergo significant changes with age), this research will also examine the possibility that age-related changes in subcortical inputs influence the accuracy with which the hippocampus represents spatial aspects if an environment. The specific goals of this proposal is to provide a comprehensive evaluation of the contributions of neural representations of space and movement in the hippocampus to impaired spatial performance by aged rats. This goal will be accomplished in two parts: First discharge of different populations of single hippocampal neurons will be correlated with specific behaviors and spatial cognitive skills of young and old animals. Also, possible age differences in factors such as attention to spatial cues will be considered in terms of age-related changes in choice accuracy and neurophysiological function. Part 2 of this proposal will assess the effects of age on subcortical modulation of hippocampal function by monitoring behavioral and physiological consequences of selective and reversible deafferentation in young and old rats performing a spatial memory task. Seven afferent structures will be examined. Temporary deafferentation will be achieved by microinjection of a local anesthetic (tetracaine) or a GABA agonist (muscimol) into afferent nuclei. Using an injection-recording procedure that was recently developed for this research, the immediate behavioral and physiological consequences of selective deafferentation, as well as recovery back to baseline conditions. will be observed. Afferent activation effects will be tested by local injection of glutamate or carbachol. In summary, these results should provide important insight into possible age-changes in the neural representation of information critical for accurate spatial behaviors.