Neurons labeled from locomotor-related ventrolateral funiculus stimulus sites in the neonatal rat spinal cord
Neurons labeled from locomotor-related ventrolateral funiculus stimulus sites in the neonatal rat spinal cord
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DOI：
10.1002/cne.10081
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发表时间：
2002-01-14
影响因子：
2.5
通讯作者：
Magnuson, DSK
中科院分区：
文献类型：
--
作者：
Antonino-Green, DM;Cheng, JG;Magnuson, DSK
用体外培养的5~8日龄大鼠脊髓/脑干标本，观察了腹外侧索(VLF)浅层纤维的起源细胞和终止区，发现VLF是诱发节律性运动样活动的部位。在对VLF施加短串刺激(50赫兹，0.5-2秒)后，记录到腰前根有节律性的运动样电活动。场电位标测显示，单次VLF刺激可在同侧延髓腹外侧区引起反应。加压注射到VLF的生物细胞素示踪实验表明，仅有少量脑干神经元被标记，这些神经元散在分布于延髓腹外侧区和外侧区。在刺激部位同侧的外侧网状核可见密集的神经末梢。标记的脊髓神经元包括在T13~L4的VII层内分布的原代大细胞群，峰值位于同侧L2和对侧L3。细胞内记录显示，一些对VLF刺激有节律性反应的L2和L3神经元可以从VLF逆行激活，潜伏期小于1.0ms。这些观察使我们推测，浅表的VLF携带着一条运动相关的束，起源于双侧腰椎板VII，终止于同侧延髓，包括外侧网状核。这一途径可能是在许多物种中已被描述的棘网状或棘网状顶盖通路的一部分，其功能仅被粗略地归因于。J.Comp.神经。442：226-238,2002。(C)2001年Wiley-Liss，Inc.
Spinal cord/brainstem preparations from 5- to 8-day-old rats, maintained in vitro, were used to determine the cells of origin and regions of termination of fibers in the superficial ventrolateral funiculus (VLF) at a site from which rhythmic locomotor-like activity can be induced. Rhythmic locomotor-like activity was recorded from lumbar ventral roots after short trains of stimuli (50 Hz for 0.5-2 seconds) delivered to the VLF. Field potential mapping revealed that single VLF stimuli elicited responses in the ipsilateral ventrolateral medulla. Tract-tracing experiments by using biocytin, pressure-injected into the VLF, showed that only a small number of brainstem neurons were labeled and these were scattered bilaterally in the ventrolateral and lateral medulla. Dense concentrations of nerve terminals were found in the lateral reticular nucleus ipsilateral to the stimulation site. Labeled spinal cord neurons included a primary population of large cells distributed bilaterally in lamina VII from T13 to L4, with peak numbers in L2 ipsilaterally and in L3 contralaterally. Intracellular recordings revealed that some L2 and L3 neurons with rhythmic responses to VLF stimulation could be activated antidromically from the VLF, with latencies of less than 1.0 msec. These observations led us to speculate that the superficial VLF carries a locomotor-related tract originating bilaterally in lumbar lamina VII and terminating in the ipsilateral medulla, including the lateral reticular nucleus. This pathway may be part of the spinoreticular or spinoreticulotectal pathway that has been described in many species, the function of which has only loosely been ascribed. J. Comp. Neurol. 442:226-238, 2002. (C) 2001 Wiley-Liss, Inc.