Raudies Florian, Brandon Mark P, Chapman G William, Hasselmo Michael E
Center for Computational Neuroscience and Neural Technology, Boston University, 677 Beacon Street, Boston, MA 02115, USA; Center of Excellence for Learning in Education, Science, and Technology, Boston University, 677 Beacon Street, Boston, MA 02115, USA.
Division of Biological Science, University of California, 9500 Gilman Drive, La Jolla, San Diego, CA 92093-0357, USA.
Brain Res. 2015 Sep 24;1621:355-67. doi: 10.1016/j.brainres.2014.10.053. Epub 2014 Nov 1.
The spatial firing pattern of entorhinal grid cells may be important for navigation. Many different computational models of grid cell firing use path integration based on movement direction and the associated movement speed to drive grid cells. However, the response of neurons to movement direction has rarely been tested, in contrast to multiple studies showing responses of neurons to head direction. Here, we analyzed the difference between head direction and movement direction during rat movement and analyzed cells recorded from entorhinal cortex for their tuning to movement direction. During foraging behavior, movement direction differs significantly from head direction. The analysis of neuron responses shows that only 5 out of 758 medial entorhinal cells show significant coding for both movement direction and head direction when evaluating periods of rat behavior with speeds above 10 cm/s and ±30° angular difference between movement and head direction. None of the cells coded movement direction alone. In contrast, 21 cells in this population coded only head direction during behavioral epochs with these constraints, indicating much stronger coding of head direction in this population. This suggests that the movement direction signal required by most grid cell models may arise from other brain structures than the medial entorhinal cortex. This article is part of a Special Issue entitled SI: Brain and Memory.
内嗅网格细胞的空间放电模式可能对导航很重要。许多不同的网格细胞放电计算模型使用基于运动方向和相关运动速度的路径积分来驱动网格细胞。然而，与多项显示神经元对头方向有反应的研究相比，神经元对运动方向的反应很少得到测试。在这里，我们分析了大鼠运动过程中头方向和运动方向之间的差异，并分析了从内嗅皮层记录的细胞对运动方向的调谐。在觅食行为期间，运动方向与头方向有显著差异。对神经元反应的分析表明，在评估大鼠行为速度高于10厘米/秒且运动与头方向之间角度差为±30°的时间段时，758个内侧内嗅细胞中只有5个对运动方向和头方向都有显著编码。没有细胞单独编码运动方向。相比之下，在这些限制条件下的行为阶段，该群体中有21个细胞仅编码头方向，表明该群体对头方向的编码要强得多。这表明大多数网格细胞模型所需的运动方向信号可能来自内侧内嗅皮层以外的其他脑结构。本文是名为“SI：大脑与记忆”的特刊的一部分。
