CHARACTERISTICS AND FUNCTIONAL IDENTIFICATION OF SACCADIC INHIBITORY BURST NEURONS IN THE ALERT MONKEY
CHARACTERISTICS AND FUNCTIONAL IDENTIFICATION OF SACCADIC INHIBITORY BURST NEURONS IN THE ALERT MONKEY
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DOI：
10.1152/jn.1988.59.5.1430
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发表时间：
1988-05-01
影响因子：
2.5
通讯作者：
LANGER, TP
中科院分区：
文献类型：
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作者：
SCUDDER, CA;FUCHS, AF;LANGER, TP
1. 通过使用单单元记录，在警觉、训练有素的恒河猴中，在紧邻外展核尾部的网状结构中寻找扫视爆发神经元。我们记录了 80 个短导联和长导联突发神经元，研究了它们的连接，并定量分析了它们的放电特性。 2. 与位于外展肌喙侧的兴奋性爆发神经元一样，这些尾部爆发神经元对于同侧定向扫视放电最佳，对于垂直扫视放电较少，对于对侧扫视放电最少（如果有的话）。与最大尖峰数量相关的方向大约沿着水平轴（1±12℃（SD）；n=33）。 3. 突发的第一个尖峰使眼跳领先 2-120 毫秒，具体取决于设备。使用 15 ms 的突发导联标准将神经元分为短导联 (45%) 和长导联 (55%)。在正方向上，两种类型的放电在爆发中的尖峰数量和水平扫视分量的大小之间表现出很强的相关性。突发持续时间和眼跳持续时间；以及眼跳的爆发频率和峰值速度的峰值频率。长导联神经元的这些关系比短导联神经元的关系更松散。 4.将辣根过氧化物酶注射到外展核中，逆行标记对侧网状结构中记录有突发神经元的细胞，表明该区域的细胞形成交叉的单突触连接。从生理学和解剖学上确定，该区域的界限之间存在良好的一致性。 5.记录的突发神经元位点的微刺激在对侧外直肌中引发肌电图电位，其具有适当的符号和潜伏期，用于单突触抑制投射到外展运动神经元。刺激还引起与对侧外直肌抑制一致的眼球运动。 6. 有人认为，这些特征使得短导联神经元很可能是传入扫视期间对侧外展运动神经元放电产生暂停的传入源。因此，这些神经元类似于猫中发现的抑制性突发神经元（IBN）。长导联突发神经元的特征，特别是它们的导联，使得它们不太可能促进这种功能。这些细胞可能更适合为全停神经元或短导 IBN 提供输入。
1. With the use of single-unit recording, the reticular formation immediately caudal to the abducens nucleus was searched for saccadic burst neurons in alert, trained rhesus monkeys. We recorded 80 short- and long-lead burst neurons, investigated their connections, and quantitatively analyzed their discharge characteristics. 2. Like excitatory burst neurons located rostral to the abducens, these caudal burst neurons fire optimally for ipsilaterally directed saccades, fire less for vertical saccades, and fire minimally, if at all, for contralateral saccades. The direction associated with the maximum number of spikes was approximately along the horizontal axis (1 .+-. 12 .degree.C (SD); n = 33). 3. The first spike of the burst led the saccade by 2-120 ms, depending on the unit. Neurons were divided into short lead (45%) and long lead (55%) using a burst-lead criterion of 15 ms. In the on-direction, the discharges of both types exhibited strong correlations between number of spikes in the burst and size of the horizontal saccade component; duration of the burst and duration of the saccade; and peak frequently of the burst and peak velocity of the saccade. These relations were looser for long-lead neurons than for short-lead neurons. 4. Horseradish peroxidase injected into the abducens nucleus retrogradely labeled cells in the contralateral reticular formation where burst neurons were recorded, showing that cells in this region make crossed monosynaptic connections. There was good agreement between the limits of this region, as determined physiologically and anatomically. 5. Microstimulation at the locus of recorded burst neurons elicited EMG potentials in the contralateral lateral rectus muscle of the appropriate sign and latency for a monosynaptic inhibitory projection to abducens motoneurons. Stimulation also elicited eye movements consistent with inhibition of the contralateral lateral rectus. 6. It is argued that these characteristics make it likely that the short-lead neurons are the source of the afference which generate the pause in contralateral abducens motoneuron firing during adducting saccades. These neurons are therefore analogues to the inhibitory burst neurons (IBNs) found in the cat. The characteristics of long-lead burst neurons, particularly their lead, make them less likely to subserve this function. These cells might be better suited to providing input to omnipause neurons or to the short-lead IBNs.