A POPULATION OF ASCENDING INTERSEGMENTAL INTERNEURONES IN THE LOCUST WITH MECHANOSENSORY INPUTS FROM A HIND LEG
A POPULATION OF ASCENDING INTERSEGMENTAL INTERNEURONES IN THE LOCUST WITH MECHANOSENSORY INPUTS FROM A HIND LEG
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DOI：
10.1002/cne.902750102
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发表时间：
1988-09-01
影响因子：
2.5
通讯作者：
BURROWS, M
中科院分区：
文献类型：
--
作者：
LAURENT, G;BURROWS, M
一个人口的约35 intersegmental interneurones与胞体在后胸神经节的特点是细胞内记录和染色。这些中间神经元整合来自后腿上的外感受器和本体感受器的信号。胞体聚集在背侧皮质的前部和外侧区域，轴突投射到同侧或对侧连接中更前部的神经节。这些中间神经元中的一些被来自股胫关节（股弦音器官）的本体感受器的传入兴奋。传入锋电位在中间神经元中引起化学介导的EPSP，其潜伏期和一致性表明连接是直接的。单个中间神经元编码股胫关节周围运动的特定特征，对屈曲、伸展或两个方向的运动做出相位或强直反应。这些中间神经元有一个广泛的领域的细分支同侧的后腿，他们接受输入。这些分支位于弦音器官的传入神经也投射到的神经节的外侧和中间区域。轴突分支，无论是同侧和对侧轴突，稀疏和静脉曲张，发生在背侧神经节。其他的中间神经元被来自外感受毛（毛状感受器）的传入兴奋。一个单独的中间神经元被后腿特定区域上的一排特殊的毛所兴奋。传入神经元和中间神经元之间的连接似乎是直接的。这些中间神经元在后肢同侧有密集而紧凑的细分支阵列，它们从后肢接收输入。这些分支位于嗜神经细胞的最腹侧区域，毛传入也投射到该区域。来自同侧轴突的分支稀疏且静脉曲张，并且发生在更多的背侧神经节中。因此，中间神经元可以为更前部的神经节提供关于后腿关节运动和外部感受性刺激位置的精确信息。该信息对于确保行走期间腿的正确协调是重要的。
A population of some 35 intersegmental interneurones with somata in the metathoracic ganglion has been characterized by intracellular recording and staining. These interneurones integrate signals from extero- and proprioceptors on a hind leg. The somata are clustered in an anterior and lateral region of the dorsal cortex, and the axons project to more anterior ganglia in either the ipsilateral or contralateral connectives. Some of these interneurones are excited by afferents from a proprioceptor at the femorotibial joint, the femoral chordotonal organ. An afferent spike evokes a chemically mediated EPSP in an interneurone with a latency and consistency that suggest that the connection is direct. An individual interneurons codes particular features of the movement about the femorotibial joint, responding to flexion, extension, or both directions of movement with either phasic or tonic responses. These interneurons have an extensive field of fine branches ipsilateral to the hind leg from which they receive input. These branches are in lateral and intermediate regions of neuropil to which the afferents of the chordotonal organ also project. Axonal branches, from either an ipsilateral and contralateral axon, are sparse and varicose and occur in dorsal neuropil. Other interneurones are excited by afferents from exteroceptive hairs (trichoid sensilla). An individual interneurone ie excited by a particular array of hairs on specific regions of a hind leg. The connections between the afferents and the interneurones appear direct. These interneurones have a dense and compact array of fine branches ipsilateral to the hind leg from which they receive input. These branches are in the most ventral region of neurophil, to which the hair afferents also project. Branches from the ipsilateral axons are sparse and varicose and occur in more dorsal neuropil. The interneurons can thus provide the more anterior ganglia with precise information about the movement of a joint in a hind leg and of the location of an exteroceptive stimulus. This information would be of importance in ensuring the correct co-ordination of the legs during walking.