Current flow in vibrissa motor cortex can phase-lock with exploratory rhythmic whisking in rat
Current flow in vibrissa motor cortex can phase-lock with exploratory rhythmic whisking in rat
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DOI：
10.1152/jn.00020.2004
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发表时间：
2004-09-01
影响因子：
2.5
通讯作者：
Kleinfeld, D
中科院分区：
文献类型：
--
作者：
Ahrens, KF;Kleinfeld, D
大鼠通过在5 - 15赫兹范围内有节奏地扫描它们的神秘触须来探索它们的环境。我们测试了触须初级运动（M1）皮层是否产生锁定这种行为输出的电活动。老鼠被训练在空气中快速移动以寻找食物奖励。神秘性垫的肌电图代替了触须位置，而长期植入的16通道硅基探针提供了整个触须M1皮层和触须初级体感（S1）皮层深度的场电位记录。测量电位用来估计沿径向轴的电流源密度。我们观察到贯穿M1皮层深度的电流流与神秘肌电图是一致的，即两个信号以确定的相位关系共变。这种一致性在三叉神经的眶下分支（IoN）横断后仍然存在，三叉神经提供来自触须的唯一感觉输入。此外，离子横断后，与神秘性肌电图一致的S1触须皮层电流也持续存在，与M1和S1之间的解剖通路一致。结合先前的观察，有节奏的，皮层内微刺激的触须M1皮层可以驱动正常的拂动运动，目前的数据支持的假设，原则上，M1皮层可以启动一个周期的基础上的触须运动。
Rats explore their environment with rhythmic sweeps of their mystacial vibrissae in the range of 5 - 15 Hz. We tested if vibrissa primary motor (M1) cortex produces electrical activity that locks to this behavioral output. Rats were trained to whisk in air in search of a food reward. The EMG of the mystacial pad served as a surrogate of vibrissa position, while chronically implanted, 16-channel Si-based probes provided a record of field potentials throughout the depth of vibrissa M1 cortex as well as vibrissa primary somatosensory (S1) cortex. The measured potentials were used to estimate the current source density along the radial axis. We observed that current flow throughout the depth of M1 cortex is coherent with the mystacial EMG, i.e., the two signals co-vary with a defined phase relation. This coherence persists after transection of the infraorbital branch (IoN) of the trigeminal nerve, which provides the sole sensory input from the vibrissae. Furthermore, current flow in vibrissa S1 cortex that is coherent with the mystacial EMG also persists after transection of the IoN, consistent with anatomical pathways between M1 and S1. In combination with a previous observation that rhythmic, intracortical microstimulation of vibrissa M1 cortex can drive normal whisking motion, the present data support the hypothesis that, in principle, M1 cortex can initiate motion of the vibrissae on a cycle-by-cycle basis.