Vestibular influences on the macaque navigation circuit

 描述（由申请人提供）：先前在啮齿动物中的研究已经确定了参与导航功能的四种主要细胞类型，包括头部方向（HD）、位置、网格和边界细胞。在啮齿类动物中，HD细胞被报道编码头部指向的方向，与动物的行为或空间位置无关，并且已经在前丘脑、海马、下托和其他海马旁区域中被鉴定。虽然已经从啮齿动物模型中了解到了很多关于HD细胞反应的信息，但它具有局限性。例如，难以确定HD单元编码的是头部方向还是注视方向。在 此外，尽管损伤研究表明HD细胞调谐依赖于前庭信号，但这些信号的类型和性质仍然不清楚。我们建议检查恒河猴，这些问题的答案可以很容易地确定HD细胞的反应。我们的第一个目标将是本地化，表征，并比较猕猴HD细胞在前丘脑和下托复合体的调谐特性。我们的第二个目标是确定这两个区域中的HD细胞是否编码头部方向或注视方向。我们将训练猕猴分离眼睛和头部位置，并使用Fisher信息分析来确定HD细胞是否与头部方向或凝视方向调节更密切相关。我们假设，大多数猕猴HD细胞编码头部方向，虽然有些可能被调整到凝视方向和相对比例的每种细胞类型可能会有所不同的前丘脑和下托。我们的第三个目标是表征HD细胞在光照和黑暗中被动旋转期间的三维重力依赖特性。该项目代表了一个新的研究领域，通过合作努力，长期目标是了解灵长类动物空间导航的机制。

 DESCRIPTION (provided by applicant): Previous studies in rodents have identified four major cell types that are involved in navigation functions, including head direction (HD), place, grid, and border cells. In rodents, HD cells are reported to encode the direction the head is pointing independent of the animal's behavior or spatial location and have been identified in the anterior thalamus, hippocampus, subiculum, and other parahippocampal regions. Although much has been learned regarding HD cell responses from the rodent model, it has limitations. For example, it has been difficult to determine if HD cells encode head direction or gaze direction. In addition, although lesion studies have shown that HD cell tuning is dependent upon vestibular cues, the type and properties of these signals remain obscure. We propose to examine HD cell responses in rhesus macaques, where answers to these questions can readily be determined. Our first goal will be to localize, characterize, and compare the tuning properties of macaque HD cells in the anterior thalamus and subiculum complex. Our second goal is to determine if HD cells in these two regions encode head direction or gaze direction. We will train macaques to dissociate eye and head position and use Fisher information analysis to determine whether HD cells are more closely related to head direction or gaze direction tuning. We hypothesize that most macaque HD cells encode head direction, although some might be tuned to gaze direction and the relative proportion of each cell type might differ between the anterior thalamus and subiculum. Our third goal is to characterize the three- dimensional, gravity-dependent properties of HD cells during passive rotations in both the light and darkness. The project represents a new area of research through a collaborative effort, with the long-term goal to understand the mechanisms underlying primate spatial navigation.