Self-motion and the hippocampal spatial metric
Self-motion and the hippocampal spatial metric
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DOI：
10.1523/jneurosci.0693-05.2005
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发表时间：
2005-08-31
影响因子：
5.3
通讯作者：
McNaughton, BL
中科院分区：
文献类型：
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作者：
Terrazas, A;Krause, M;McNaughton, BL
自我运动信号对于动物导航（“路径整合”）和更新海马位置特异性放电是足够的。研究了大鼠在圆形轨道上的位置之间行走或驾驶汽车（分别称为WALK和CAR）或经历伪运动（动物静止而环境旋转）时，走动、前庭和视觉自运动信号对CA 1单位活动和EEG的贡献。较少的锥体细胞表达的地方领域在CAR和那些表现出显着更大的地方领域。遍历位置场所需的θ周期数增加，而θ相位的斜率与位置函数的发射减小。地点字段的存在和/或位置在条件之间没有很好的相关性。这些影响在WORLD期间更加突出。这些结果是无法解释的一个简单的“涂抹”的地方字段，但在大小的地方字段相对于轨道的大小，将观察到的，如果轨道周长减少，动物在它周围移动相应的速度较慢。Theta（及其14-18 Hz谐波）功率取决于速度，但在CAR和WORLD期间，该函数的增益大幅降低，就好像大鼠移动得更慢一样。海马种群矢量更新的空间尺度似乎主要来自自运动速度信号的增益，其中自运动速度信号具有近似相等的分量，这些分量来自于安培、前庭和光流信号。
Self-motion signals are sufficient for animal navigation ("path integration") and for updating hippocampal location-specific firing. The contributions of ambulatory, vestibular, and optic self-motion signals to CA1 unit activity and EEG were studied while rats either walked or drove a car between locations on a circular track ( referred to as WALK and CAR, respectively) or experienced pseudomotion, in which the animal was stationary and the environment was rotated ( WORLD). Fewer pyramidal cells expressed place fields during CAR and those that did exhibited substantially larger place fields. The number of theta cycles required to traverse a place field increased, whereas the slope of the theta phase of firing versus position function was reduced. The presence and/or location of place fields were not well correlated between conditions. These effects were even more accentuated during WORLD. These results are not explainable by a simple " smearing out" of place fields but, in terms of size of place fields relative to the track size, are comparable with what would be observed if the track circumference was reduced and the animal moved around it at a correspondingly slower speed. Theta ( and its 14-18 Hz harmonic) power were dependent on velocity, but the gain of this function was substantially reduced during CAR and WORLD, again as if the rat were moving more slowly. The spatial scale over which the hippocampal population vector is updated appears to be derived primarily from the gain of a self-motion velocity signal with approximately equal components derived from ambulation, vestibular, and optic-flow signals.