Activity of neurons in the beta nucleus of the inferior olive of the rabbit evoked by natural vestibular stimulation.
Activity of neurons in the beta nucleus of the inferior olive of the rabbit evoked by natural vestibular stimulation.
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自然前庭刺激引起的兔子下橄榄β核中神经元的活动。
DOI：
10.1007/bf00230288
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发表时间：
1993
影响因子：
2
通讯作者：
Shojaku,H
中科院分区：
文献类型：
--
作者：
Barmack,NH;Fagerson,M;Fredette,BJ;Mugnaini,E;Shojaku,H
下橄榄核(IO)似乎在功能上被组织在接受递质特异性输入的离散亚核中。特别是，IO接受GABA能输入，该输入最密集地集中在β核。在本实验中，我们通过记录兔IO区β核神经元在自然前庭刺激和视动刺激时的活动来检测其功能特异性。将兔麻醉，放置在三轴伺服控制的转速台上，头部固定在旋转中心。轮廓丰富的视觉刺激被背投到一个70度的切线屏幕上，并以恒定的速度移动。随后对标记的微小病变进行组织学分析，以验证β核中的记录位置。β核神经元对前庭纵轴翻滚刺激有反应。当兔被滚动到记录部位的对侧时，这些神经元被兴奋，当兔被同侧滚动时，这些神经元被抑制。在75个对前庭滚动刺激有反应的β核神经元中，有38个神经元对静态倾斜也有反应，这表明前庭输入起源于耳石和垂直的半规管。这些神经元的调制活动都不能归因于刺激水平半规管。所有被记录的神经元均位于小脑结节注射β后逆行标记的区域。使用“零点”技术，我们发现从前半规管和后半规管到β核的信息有不同的投射。刺激同侧前对侧后半规管可调节μ核尾侧500μm神经元的活动。刺激同侧后对侧前半规管可调节位于吻侧的神经元的活动。β核神经元及其参与的橄榄小脑环路可能是姿势反射控制和适应性改变的重要途径。
The inferior olive (IO) appears to be organized functionally in discrete subnuclei that receive transmitter-specific inputs. In particular, the IO receives a GABAergic input that is most densely concentrated in the β -nucleus. In this experiment, we examined the functional specificity of neurons in the β -nucleus of the IO of rabbits by recording their activity during natural vestibular and optokinetic stimulation. Rabbits were anesthetized and positioned in a triaxial servo- controlled rate table with the head fixed at the center of rotation. Contour-rich visual stimuli were rear-projected onto a 70 deg tangent screen and moved at constant velocities. Recording sites in the β -nucleus were verified by subsequent histological analysis of marking microlesions. Neurons in the β -nucleus responded to roll vestibular stimulation about the longitudinal axis. These neurons were excited when the rabbit was rolled onto the side which was contralateral to the recording site, and inhibited when the rabbit was rolled ipsilaterally. Thirty-eight of the 75 β -nucleus neurons that were responsive to roll vestibular stimulation also responded to static tilt, indicating an otolithic as well as a vertical semicircular canal origin of the vestibular input. The modulated activity of none of the neurons could be attributed to stimulation of the horizontal semicircular canals. All the recorded neurons were found in a region of the β -nucleus that was retrogradely labeled following HRP injections into the cerebellar nodulus. Using a “null point” technique, we found that there was a differential projection of information from the anterior and posterior semicircular canals onto to the β -nucleus. Stimulation of the ipsilateral anterior-contralateral posterior semicircular canals modulates activity of the neurons in the caudal 500 μm of the β -nucleus. Stimulation of the ipsilateral posterior-contralateral anterior semicircular canals modulates activity of neurons located more rostrally. β -nucleus neurons and the olivocerebellar circuits in which they participate may constitute an important pathway for the control and adaptive modification of postural reflexes.