Department of Integrative Neuroscience, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama, 930-0194, Japan.
Department of Integrative Neuroscience, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama, 930-0194, Japan.
Neurosci Lett. 2019 May 14;701:32-37. doi: 10.1016/j.neulet.2019.02.009. Epub 2019 Feb 8.
The activity of hippocampal cell assemblies is considered to function as the neural substrate for a cognitive map in various animal species. The firing rate of hippocampal place cells increases when an individual animal reaches a specific location in an environment. Although cumulative views on place cells have been revealed by studies using rodents under free-behavior conditions, few studies have addressed the spatial representation provided by hippocampal neurons in primates. Moreover, although previous work in rats has demonstrated the importance of locomotion velocity and direction in the spatially selective discharge of hippocampal neurons, it remains unknown whether a corresponding phenomenon exists in the primate hippocampus. In the present study, we recorded the activity and investigated the spatial representation of the hippocampal neurons in a freely behaving monkey performing a shuttle-movement task. We observed increased activity in a subset of hippocampal neurons (place cells) when the monkey crossed a particular location. Many of the monkey place cells exhibited sensitivity to locomotion velocity rather than to locomotion direction. These results suggest the existence of primate hippocampal place cells comparable to those in rodents, with the exception that, in primates, velocity information has a stronger impact on place cell activity than directional information.
海马体细胞组合的活动被认为是各种动物认知地图的神经基础。当个体动物到达环境中的特定位置时，海马体位置细胞的放电频率会增加。尽管在自由行为条件下使用啮齿动物进行的研究已经揭示了关于位置细胞的综合观点，但很少有研究涉及灵长类动物中海马神经元提供的空间表示。此外，尽管之前在大鼠中的研究表明运动速度和方向在海马神经元的空间选择性放电中很重要，但在灵长类动物的海马体中是否存在相应的现象仍然未知。在本研究中，我们记录了一只自由活动的猴子在执行穿梭任务时的海马体神经元的活动，并研究了它们的空间表示。当猴子穿过特定位置时，我们观察到一小部分海马体神经元（位置细胞）的活动增加。许多猴子的位置细胞对运动速度敏感，而不是对运动方向敏感。这些结果表明，除了在灵长类动物中，速度信息对位置细胞活动的影响比方向信息更强之外，存在与啮齿动物相当的灵长类动物海马体位置细胞。
