HIPPOCAMPAL SPATIAL REPRESENTATIONS

人们经常观察到，由于正常衰老，空间能力会下降 在人类和老鼠身上都是如此。为了……的未来发展 适当的治疗方法，有必要了解 与年龄相关的脑组织变化的贡献。海马体 是这方面研究的一个特别有趣的结构，因为它 被认为是获取新空间信息的关键，以及 它似乎特别容易受到年龄相关的病理改变的影响。 异常现象。因此，这项研究一本正经的、枯燥的重点是理解 老年人生理特性之间的关系 大鼠的海马区结构和空间表现。自突触 海马区的激活受到不同基因的广泛调控 皮质下传入(其中一些已知经历了显著的 随着年龄的变化)，这项研究还将考察 大脑皮质下输入的年龄相关变化会影响识别的准确性 如果是一个环境，海马体代表了空间方面。 这项提案的具体目标是提供一个全面的 空间和空间的神经表征的贡献评估 海马区运动对老年大鼠空间操作能力的损害。 这一目标将分两部分实现：第一，不同的排放 单个海马神经元的群体将与特定的 幼年和老年动物的行为和空间认知技能。另外， 在注意空间线索等因素上可能的年龄差异将 要考虑与年龄相关的选择准确率和 神经生理功能。本建议书的第二部分将评估 年龄对海马皮层下调节海马区功能的影响 监测选择性和非选择性的行为和生理后果 青年大鼠和老年大鼠空间运动的可逆性去传入 记忆任务。七个传入结构将被检查。暂时性 去传入将通过微量注射局部麻醉剂来实现 (丁卡因)或GABA激动剂(麝香酚)注入传入核团。使用 最近为此开发的注射记录程序 研究表明，这种行为和生理上的直接后果 选择性去传入，以及恢复到基线状态。 将会被遵守。传入激活效应将由本地测试 注射谷氨酸或卡巴胆碱。总而言之，这些结果应该 对神经中可能的年龄变化提供重要的洞察 对准确的空间行为至关重要的信息表示。

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.