HIPPOCAMPAL AND CORTICAL MEMORY STSYEMS

令人信服的证据表明，海马结构和 内侧颞叶的皮层区域 参与学习和记忆。但目前尚不清楚， 这个系统的各个组成部分对正常的 学习和记忆，并且在这方面缺乏共识。 由这些结构提供的特定记忆处理功能。的 拟议的研究将在一系列研究中解决这些问题， 猴（Macaca fascicularis）。正在调查的主要假设 海马体、内嗅、嗅周和海马旁 皮层介导学习和记忆的不同和可分离的方面。 这个解释表明海马体有选择地参与存储 表示内存中项之间的关系，并支持 灵活地使用这种代表性组织的能力， 从记忆中推断和归纳。 大脑皮层 该系统被视为有助于不同的功能， 在超过即时时间跨度的延迟期间维护信息 记忆为了评估这一建议，新的行为测试程序将 被开发用于检查关系记忆过程和灵活的 猴子的记忆表达。其中一组任务将以 使用设计用于评估配对关联的程序的手动测试设备 学习，学习和记忆的层次关系，和 序贯学习另一组任务将利用一个大型开放式 领域迷宫提供第一个系统的评估学习和 自由移动猴子的空间关系记忆。探针测试将 纳入每个程序，以确认性能基于 关系记忆过程更多标准的行为结果 学习和记忆任务（延迟不匹配到样本和保留 物体辨别）将提供基线数据， 关系记忆任务对海马的敏感性和选择性 系统损坏。 拟议项目将利用这一新的 开发测试电池，以定义特定的存储器处理功能 由海马系统的各个组成部分辅助。单独 将制备穹窿选择性损伤的猴组，或 海马（包括齿状回和下托复合体）。或 鼻周和海马旁皮质同时受损 这些群体的行为结果将与以下因素的影响进行比较： 更大的病变涉及海马和皮质成分， the system. 内部职能进一步专业化的潜力 海马系统将在实验中进行评估， 选择性的内嗅、嗅周或海马旁的后果 皮质病变 综合起来，这些研究应该会导致一个更 个体记忆功能的精确规范 海马系统的组成部分，并应有助于使 来自实验室动物模型的对应结果， 神经心理学研究人类健忘症

Compelling evidence has demonstrated that the hippocampal formation and closely associated cortical regions in the medial temporal lobe critically participate in learning and memory. It remains unclear however whether the individual components of this system are all equally important for normal learning and memory and there is a marked lack of consensus concerning the specific mnemonic processing functions subserved by these structures. The proposed research will address these issues in a series of studies in the monkey (Macaca fascicularis). The principal hypothesis under investigation is that the hippocampus and the entorhinal, perirhinal and parahippocampal cortices mediate distinct and dissociable aspects of learning and memory. This account suggests the hippocampus selectively participates in storing representations of the relationships between items in memory, and supports the ability to use this representational organization flexibly in making inferences and generalizations from memory. The cortical components of the system are viewed as subserving a different function involving the maintenance of information over delays that exceed the span of immediate memory. To evaluate this proposal, new behavioral testing procedures will be developed for examining relational memory processes and the flexible expression of memory in monkeys. One set of tasks will be conducted in a manual test apparatus using procedures designed to assess paired associate learning, learning and memory for hierarchical relationships, and sequential order learning. Another set of tasks will utilize a large open field maze to provide the first systematic evaluation of learning and memory for spatial relations in the freely moving monkey. Probe tests will be incorporated in each procedure to confirm that performance is based on relational memory processes. Behavioral results from more standard learning and memory tasks (delayed non-matching-to-sample and retention of object discriminations) will provide baseline data for assessing the sensitivity and selectivity of relational memory tasks to hippocampal system damage. The proposed project will capitalize on this newly developed test battery to define the specific memory processing functions subserved by individual components of the hippocampal system. Separate groups of monkeys will be prepared with selective lesions of the fornix or the hippocampus (including the dentate gyrus and subicular,complex). or with combined damage to the perirhinal and parahippocampal cortices. Behavioral results from these groups will be compared with the effects of larger lesions involving both the hippocampal and cortical components of the system. The potential for further functional specialization within the hippocampal system will be evaluated in experiments examining the consequences of selective entorhinal, perirhinal, or parahippocampal cortical lesions. Taken together, these studies should lead to a more precise specification of the memory functions mediated by individual components of the hippocampal system, and should help bring into correspondence results from laboratory animal models and neuropsychological research on human amnesia.