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/sec 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.
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机译：内嗅网格细胞的空间发射模式可能对导航很重要。网格单元点火的许多不同计算模型都使用基于运动方向和关联运动速度的路径积分来驱动网格单元。但是，与多项研究表明神经元对头部方向的反应相反，很少测试神经元对运动方向的反应。在这里，我们分析了大鼠运动过程中头部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以适应运动方向。在觅食行为中，运动方向与头部方向明显不同。对神经元反应的分析表明，当评估大鼠行为周期超过10 cm / sec且运动与头部方向之间的角度差为±30°时，在758个内侧内嗅神经细胞中只有5个显示出运动方向和头部方向的显着编码。没有任何一个单元单独编码运动方向。相比之下，该种群中的21个单元格在具有这些约束的行为时期期间仅编码了头部方向，表明该种群中的头部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大脑结构。
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