Feedforward Inhibition Determines the Angular Tuning of Vibrissal Responses in the Principal Trigeminal Nucleus
Feedforward Inhibition Determines the Angular Tuning of Vibrissal Responses in the Principal Trigeminal Nucleus
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DOI：
10.1523/jneurosci.4805-09.2010
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发表时间：
2010-01-20
影响因子：
5.3
通讯作者：
Deschenes, Martin
中科院分区：
文献类型：
--
作者：
Bellavance, Marie-Andree;Demers, Maxime;Deschenes, Martin
将触须信息传递到丘脑的三叉神经元接收来自对触须运动不同方向敏感的一级传入神经的输入。这就提出了一个问题：在触须系统的中枢中继站中，方向选择性是如何维持的。在本研究中，我们对大鼠三叉神经主核细胞的角度选择性特性进行了详细分析。我们发现刺激方向会系统地影响反应潜伏期，因此，用首次放电潜伏期计算出的方向选择性程度和偏好偏转角所得到的结果与用放电次数得到的结果几乎相似。此外，我们发现抑制作用增强了方向选择性，并且抑制作用的药理学阻断显著降低了细胞反应的角度选择性。这些结果表明，触须系统第一个中继站中细胞的角度选择性是由快速前馈抑制决定的，这种抑制在突触整合的最初阶段就塑造了兴奋性输入。
Trigeminal neurons that relay vibrissal messages to the thalamus receive input from first-order afferents that are tuned to different directions of whisker motion. This raises the question of how directional tuning is maintained in central relay stations of the whisker system. In the present study we performed a detailed analysis of the angular tuning properties of cells in the principal trigeminal nucleus of the rat. We found that stimulus direction systematically influences response latency, so that the degree of directional tuning and the preferred deflection angle computed with first-spike latency yielded results nearly similar to those obtained with spike counts. Furthermore, we found that inhibition sharpens directional selectivity, and that pharmacological blockade of inhibition markedly decreases the angular tuning of cellular responses. These results indicate that the angular tuning of cells in the first relay station of the vibrissal system is determined by fast feedforward inhibition, which shapes excitatory inputs at the very beginning of synaptic integration.