Superior colliculus control of vibrissa movements
Superior colliculus control of vibrissa movements
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DOI：
10.1152/jn.90478.2008
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发表时间：
2008-09-01
影响因子：
2.5
通讯作者：
Keller, Asaf
中科院分区：
文献类型：
--
作者：
Hemelt, Marie E.;Keller, Asaf
这项研究测试了上丘在产生神秘触须运动（搅拌）中的作用。首先，我们比较了上丘产生的搅拌运动学与运动皮层产生的搅拌运动学。我们发现，在麻醉的大鼠中，丘的微刺激引起持续的触须延长，而运动皮层的刺激则产生有节奏的延长。上丘产生的运动独立于运动皮层，并且可以比运动皮层产生的运动以更低的阈值和更短的潜伏期诱发。接下来，我们测试了这样的假设：丘充当一个简单的反射环，其中驱动触须运动的神经元接收由触须接触引起的感觉输入。我们发现大多数顶盖面神经元不接收感觉输入。这些神经元不仅没有响应感觉刺激而出现尖峰，而且场电位分析显示，阈下感觉输入在空间上与顶盖面神经元不重叠。这些发现共同表明，上丘在触须运动中起着关键作用 - 调节触须设定点和搅拌幅度 - 但并不起到简单的反射回路的作用。由于运动皮层控制搅拌频率，设定点和振幅的上丘控制将解释自愿搅拌的主要参数。
This study tested the role of the superior colliculus in generating movements of the mystacial vibrissae - whisking. First, we compared the kinematics of whisking generated by the superior colliculus with those generated by the motor cortex. We found that in anesthetized rats, microstimulation of the colliculus evoked a sustained vibrissa protraction, whereas stimulation of motor cortex produced rhythmic protractions. Movements generated by the superior colliculus are independent of motor cortex and can be evoked at lower thresholds and shorter latencies than those generated by the motor cortex. Next we tested the hypothesis that the colliculus is acting as a simple reflex loop with the neurons that drive vibrissa movement receiving sensory input evoked by vibrissa contacts. We found that most tecto-facial neurons do not receive sensory input. Not only did these neurons not spike in response to sensory stimulation, but field potential analysis revealed that subthreshold sensory inputs do not overlap spatially with tecto-facial neurons. Together these findings suggest that the superior colliculus plays a pivotal role in vibrissa movement - regulating vibrissa set point and whisk amplitude - but does not function as a simple reflex loop. With the motor cortex controlling the whisking frequency, the superior colliculus control of set point and amplitude would account for the main parameters of voluntary whisking.