CAA: Comparative Studies of Spatial and Nonspatial Memory inMammals

海马体的大小与野生啮齿动物的空间行为有关。海马体是一种已知的大脑结构，负责调节空间学习。在这个职业发展奖中，将对不同物种在抽象学习任务上的空间学习能力进行比较。使用操作法，已知的海马体大小不同的两对物种将在两项已知涉及海马区的可操作性任务(空间延迟与样本不匹配，同时气味识别)和两项不需要完整海马区的任务(听觉识别，连续嗅觉识别)上进行比较。我们将对两种袋鼠和两种田鼠进行比较。据预测，在每个属中，海马体较大的物种在海马体任务上表现出更好的学习能力，特别是在空间任务上，但在非海马体任务上应该没有物种差异。由于几个原因，拟议的研究将具有重要意义。这将是第一次对野生啮齿动物不同类型的记忆进行比较研究。因为我们对哺乳动物记忆生理学的理解主要是基于实验鼠，所以了解实验鼠是否表现出典型的啮齿动物行为是很重要的。更重要的是，对密切相关的啮齿动物物种进行比较研究，可以确定一个物种的栖息地的哪些特征可以提高学习和记忆能力。这项研究不仅可以帮助我们了解动物记忆的进化，还可以帮助我们了解海马体，这是动物和人类记忆中的一个关键结构。例如，没有其他动物研究试图比较涉及海马体的不同任务的表现(迷宫学习、气味辨别)。因此，这项研究不仅将揭示记忆的进化，而且还将揭示具有临床重要性的结构--海马体的功能。

The size of the hippocampus, a brain structure known to mediate spatial learning, is correlated with spatial behavior in wild rodents. In this career advancement award, a comparison will be made of the spatial learning ability of different species on abstract learning tasks. Using operant methods, pairs of species, known to differ in hippocampal size, will be compared on two operant tasks known to involve the hippocampus (spatial delayed- nonmatch-to-sample, simultaneous odor discrimination) and two tasks that do not require an intact hippocampus (auditory discrimination, successive olfactory discrimination). Two species of kangaroo rats (Dipodomys) and two species of voles (Microtus) will be compared. It is predicted that, within each genus, the species with a larger hippocampus will show superior learning ability on hippocampal tasks, particularly the spatial task, but that there should be no species differences on nonhippocampal tasks. The proposed study will be significant for several reasons. It will be the first comparative study of different types of memory in wild rodents. Because our understanding of the physiology of memory in mammals is largely based on the laboratory rat, it is important to know if laboratory rats show typical rodent behavior. More importantly, comparative studies of closely related rodent species can identify what features of a species's habitat can lead to increases in learning and memory capacity. Not only can this study help us to understand the evolution of animal memory, but it can also help us to understand the hippocampus, a structure critical in both animal and human memory. For example, no other animal study has attempted to compare performance of different tasks involving the hippocampus (maze learning, odor discrimination). Thus, this study will shed light not only on the evolution of memory, but on the function of the hippocampus, a structure of clinical importance.