Progressive Increase in Grid Scale From Dorsal to Ventral Medial Entorhinal Cortex
Progressive Increase in Grid Scale From Dorsal to Ventral Medial Entorhinal Cortex
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DOI：
10.1002/hipo.20504
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发表时间：
2008-01-01
期刊：
影响因子：
3.5
通讯作者：
Moser, May-Britt
中科院分区：
文献类型：
--
作者：
Brun, Vegard Heimly;Solstad, Trygve;Moser, May-Britt
网格细胞的地形组织的意义上说，在背侧部分的内侧内嗅皮层，规模的网格增加系统的解剖距离从这个脑区的背侧边界。空间图的腹侧界限目前尚不清楚。为了确定网格图是否延伸到内侧内嗅皮层的中间和腹侧部分，我们记录了内嗅主细胞在多个背腹侧水平的活动，而大鼠在18米长的线性轨道上来回穿梭。记录跨越了超过3毫米的范围，覆盖了大约四分之三的背腹侧内侧内嗅皮层的程度。在所有记录水平均观察到明显的周期性放电场。平均峰间距离的字段增加，从类似的50厘米，在最背侧的部分，以类似的3米，在最腹侧的记录位置。网格尺度的增加伴随着θ调制频率和相位进动速率的降低。平均间距和字段大小的增加是近似线性的，但这种关系正好与每个措施的变异性大幅增加。两者合计，观察结果表明，网格表示的空间尺度逐渐增加沿着大部分的背腹轴内侧内嗅皮层，反映了地形尺度扩张观察到的地方细胞在海马。(C)2008 Wiley-Liss，Inc.
Grid cells are topographically organized in the sense that, within the dorsal part of the medial entorhinal cortex, the scale of the grid increases systematically with anatomical distance from the dorsal border of this brain area. The ventral limit of the spatial map is currently not known. To determine if the grid map extends into the intermediate and ventral parts of the medial entorhinal cortex, we recorded activity from entorhinal principal cells at multiple dorsoventral levels while rats shuttled back and forth on an 18 m long linear track. The recordings spanned a range of more than 3 mm, covering approximately three quarters of the dorsoventral extent of the medial entorhinal cortex. Distinct periodic firing fields were observed at all recording levels. The average interpeak distance between the fields increased from similar to 50 cm in the most dorsal part to similar to 3 m at the most ventral recording positions. The increase in grid scale was accompanied by a decrease in the frequency of theta modulation and the rate of phase precession. The increase in average spacing and field size was approximately linear but this relationship coincided with a substantial increase in the variability of each measure. Taken together, the observations suggest that the spatial scale of the grid representation increases progressively along most of the dorsoventral axis of the medial entorhinal cortex, mirroring the topographical scale expansion observed in place cells in the hippocampus. (C) 2008 Wiley-Liss, Inc.