Second-order vestibular neuron morphology of the extra-MLF anterior canal pathway in the cat.
Second-order vestibular neuron morphology of the extra-MLF anterior canal pathway in the cat.
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猫 MLF 前管通路外的二级前庭神经元形态。
DOI：
10.1007/bf00241532
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发表时间：
1994
影响因子：
2
通讯作者：
Graf,W
中科院分区：
文献类型：
--
作者：
Uchino,Y;Sasaki,M;Isu,N;Hirai,N;Imagawa,M;Endo,K;Graf,W
二阶前庭神经元形成前庭动眼神经三神经元弧的中心环节，介导代偿性眼球运动。大多数提供垂直前庭眼反射的轴突在内侧纵束（MLF）中向动眼核和滑车核中的目标神经元上升。我们现在已经确定了前半规管系统中单个兴奋性二级神经元的形态，这些神经元在 MLF 之外延伸到动眼神经核。数据通过细胞内辣根过氧化物酶法获得。 MLF 外前管神经元的细胞体位于前庭上核。主轴突上升穿过结膜臂下方的深层网状结构，到达桥脑被盖网状核的吻端范围，并在此穿过中线。主轴突继续其轨迹至红核的尾部边缘，从那里返回动眼核。在动眼神经核内，侧枝到达上直肌和下斜运动神经元。一些轴突分支重新穿过动眼核内的中线并到达该侧的上直肌运动神经元细分。由于这些神经元不向脊髓发出侧支循环，因此它们被归类为前庭动眼神经类型，并被认为专门参与眼球运动控制。该前管前庭动眼神经元类的信号内容和空间调谐特征仍有待确定。
Second-order vestibular neurons form the central links of the vestibulo-oculomotor three-neuron arcs that mediate compensatory eye movements. Most of the axons that provide for vertical vestibulo-ocular reflexes ascend in the medial longitudinal fasciculus (MLF) toward target neurons in the oculomotor and trochlear nuclei. We have now determined the morphology of individual excitatory second-order neurons of the anterior semicircular canal system that course outside the MLF to the oculomotor nucleus. The data were obtained by the intracellular horseradish peroxidase method. Cell somata of the extra-MLF anterior canal neurons were located in the superior vestibular nucleus. The main axon ascended through the deep reticular formation beneath the brachium conjunctivum to the rostral extent of the nucleus reticularis tegmenti pontis, where it crossed the midline. The main axon continued its trajectory to the caudal edge of the red nucleus from where it coursed back toward the oculomotor nucleus. Within the oculomotor nucleus, collaterals reached superior rectus and inferior oblique motoneurons. Some axon branches recrossed the midline within the oculomotor nucleus and reached the superior rectus motoneuron subdivision on that side. Since these neurons did not give off a collateral toward the spinal cord, they were classified as being of the vestibulo-oculomotor type and are thought to be involved exclusively in eye movement control. The signal content and spatial tuning characteristics of this anterior canal vestibulo-oculomotor neuron class remain to be determined.