ANATOMY AND PHYSIOLOGY OF SACCADIC BURST NEURONS IN THE ALERT SQUIRREL-MONKEY .1. EXCITATORY BURST NEURONS
ANATOMY AND PHYSIOLOGY OF SACCADIC BURST NEURONS IN THE ALERT SQUIRREL-MONKEY .1. EXCITATORY BURST NEURONS
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DOI：
10.1002/cne.902490303
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发表时间：
1986-07-15
影响因子：
2.5
通讯作者：
MCCREA, RA
中科院分区：
文献类型：
--
作者：
STRASSMAN, A;HIGHSTEIN, SM;MCCREA, RA
在猫和猴的病变和细胞外记录研究的基础上，脑桥网状结构中的扫视爆发神经元与水平面上扫视的产生有关。在本研究中，扫视爆发神经元的解剖和生理特点，轴突内记录和注射辣根过氧化物酶在警觉的松鼠猴。爆发神经元的人口被发现，出现类似于兴奋性爆发神经元（EBNs）先前描述的猫。所有的神经元都位于脑桥尾侧网状结构，并有一个主要的轴突投射到同侧展神经核。额外的预测被发现的前庭内侧核，前置核，脑桥和延髓网状结构的区域，腹侧和尾侧的外展神经。所有的神经元只在扫视过程中放电，其放电模式类似于之前在猫和猴中描述的中导联爆发神经元。在大多数神经元中，扫视爆发在扫视开始之前5-15毫秒开始。爆发持续时间与眼跳持续时间、爆发中的棘波数与眼跳幅度、放电频率与瞬时速度之间存在线性关系。每个神经元的生理活动与特定方向的眼跳分量的幅度关系最密切。对于所有的神经元，这个方向是在同侧半野，主要是水平的，但可能有向上或向下的垂直分量。这些结果支持了猴的EBNs在产生扫视爆发外展运动神经元，以及在其他类别的前运动神经元的动眼神经活动的贡献的主要作用。
Saccadic burst neurons in the pontine reticular formation have been implicated in the generation of saccades in the horizontal plane on the basis of lesion and extracellular recording studies in the cat and monkey. In the present study, saccadic burst neurons were anatomically and physiologically characterized with intraaxonal recording and injection of horseradish peroxidase in the alert squirrel monkey. A population of burst neurons were found that appear analogous to the excitatory burst neurons (EBNs) described previously in the cat. All neurons are located in the caudal pontine reticular formation and have a major axonal projection to the ipsilateral abducens nucleus. Additional projections were found to the medial vestibular nucleus, the nucleus prepositus, and regions of the pontine and medullary reticular formation rostral, ventral, and caudal to the abducens. All neurons fire exclusively during saccades and have a discharge pattern similar to that of medium-lead burst neurons described previously in the cat and monkey. In most neurons the saccadic burst begins 5-15 msec before saccade onset. Linear relationships exist between burst duration and saccade duration, number of spikes in the burst and saccade amplitude, and firing frequency and instantaneous velocity. Physiological activity of each neuron shows the closest relationship with the amplitude of the saccade component in a particular direction. For all neurons, this on-direction is in the ipsilateral hemifield and is predominantly horizontal, but may have either an upward or downward vertical component. These results support a major role for the EBNs in the monkey in generating the saccadic burst in abducens motoneurons, as well as in contributing to the oculomoter activity in other classes of premotor neurons.