Disynaptic inhibition of omnipause neurons following electrical stimulation of the superior colliculus in alert cats
Disynaptic inhibition of omnipause neurons following electrical stimulation of the superior colliculus in alert cats
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DOI：
10.1152/jn.2001.85.6.2639
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发表时间：
2001-06-01
影响因子：
2.5
通讯作者：
Shimazu, H
中科院分区：
文献类型：
--
作者：
Yoshida, K;Iwamoto, Y;Shimazu, H
研究了刺激警觉猫上级丘（SC）后，引起全间歇神经元（OPN）抑制的突触组织。刺激电极双侧植入在喙和尾侧SC，其中短脉冲序列分别诱导小和大的扫视。单脉冲刺激对OPN的影响用细胞内和细胞外记录进行了检查。与刺激吻侧SC诱发的单突触兴奋性突触后电位相反，在大多数OPN中，吻侧和尾侧SC的双突触潜伏期（1.3-1.9 ms）可诱发抑制性突触后电位。一个更大的细胞外样品的分析补充细胞内的观察。OPN的单突触激活引起更频繁地从吻侧网站比从尾侧网站，而尖峰抑制与双突触lavelets诱导的尾侧以及吻侧刺激具有相似的频率。结果表明，双突触抑制是由分布在与不同大小的扫视相关的广泛区域的SC细胞的激活产生的。我们认为，这些神经元的信号通过单个抑制性中间神经元启动OPNs的扫视暂停。
We investigated the synaptic organization responsible for the inhibition of omnipause neurons (OPNs) following stimulation of the superior colliculus (SC) in alert cats. Stimulation electrodes were implanted bilaterally in the rostral and caudal SC where a short-pulse train induced small and large saccades, respectively. Effects of single-pulse stimulation on OPNs were examined with intracellular and extracellular recordings. In contrast to monosynaptic excitatory postsynaptic potentials, which were induced by rostral SC stimulation, inhibitory postsynaptic potentials were induced with disynaptic latencies (1.3-1.9 ms) from both the rostral and caudal SC in most OPNs. Analysis of a larger extracellular sample complemented intracellular observations. Monosynaptic activation of OPNs was elicited more frequently from rostral sites than from caudal sites, whereas spike suppression with disynaptic latencies was induced by caudal as well as rostral stimulation with similar frequencies. The results imply that disynaptic inhibition is produced by activation of SC cells that are distributed over wide regions related to saccades of different sizes. We suggest that signals from these neurons initiate a saccadic pause of OPNs through single inhibitory interneurons.