Laurent G
J Neurosci. 1987 Sep;7(9):2977-89. doi: 10.1523/JNEUROSCI.07-09-02977.1987.
Intracellular recordings were made simultaneously from pairs of spiking local and intersegmental interneurons in the mesothoracic ganglion of the locust Schistocerca gregaria (Forskal). The spiking local interneurons belong to a midline group, and the intersegmental interneurons to a lateral-posterior population that projects ipsilaterally to the metathoracic ganglion. Both respond to mechanosensory inputs from one middle leg. The receptive fields of both types of interneurons were plotted and the contribution of the local interneurons to the shaping of the receptive fields of the intersegmental interneurons was studied. The spiking local interneurons are excited by specific arrays of exteroreceptors and proprioceptors of one leg. They make inhibitory connections with specific intersegmental interneurons which thus have corresponding inhibitory regions to their receptive fields. For example, inhibition from local interneurons with inputs from hairs or campaniform sensilla on the tarsus could sharpen the boundaries of the excitatory receptive field of an intersegmental interneuron by lateral inhibition. Inhibition from local interneurons with inputs from joint proprioceptors suppresses the excitation of an intersegmental interneuron during the antipreferred direction of movement. Rapid alternate movements about one joint can in this way be signaled by an intersegmental interneuron in a phase-locked manner. Certain intersegmental interneurons are excited by exteroreceptive inputs and inhibited by proprioceptive signals, or vice versa. The inhibition could become significant during walking, where the excitatory and inhibitory inputs to an interneuron are likely to be evoked during the different phases of a step cycle. The inhibitory regions of the receptive field of an intersegmental interneuron have never been found to be smaller than the excitatory regions of the receptive field of a presynaptic local interneuron and can result from converging inhibitory inputs from several spiking local interneurons. The inhibitory connections are highly specific: Several local interneurons may be excited by a particular stimulus that also inhibits an intersegmental interneuron, but only a small proportion of the former are the cause of the inhibition in the intersegmental interneuron.
对群居沙漠蝗（Forskal）中胸神经节内的成对脉冲发放的局部中间神经元和节间中间神经元进行了细胞内记录。脉冲发放的局部中间神经元属于中线组，节间中间神经元属于后外侧群体，它们向同侧的后胸神经节投射。两者都对来自一条中腿的机械感觉输入作出反应。绘制了两种类型中间神经元的感受野，并研究了局部中间神经元对节间中间神经元感受野形成的贡献。脉冲发放的局部中间神经元由一条腿的特定外感受器和本体感受器阵列激发。它们与特定的节间中间神经元形成抑制性连接，因此这些节间中间神经元具有与其感受野相对应的抑制区域。例如，来自跗节上毛或钟形感受器输入的局部中间神经元的抑制作用，可以通过侧向抑制来锐化节间中间神经元兴奋性感受野的边界。来自关节本体感受器输入的局部中间神经元的抑制作用，在运动的反偏好方向期间抑制节间中间神经元的兴奋。这样，围绕一个关节的快速交替运动可以由节间中间神经元以锁相方式发出信号。某些节间中间神经元由外感受性输入激发并被本体感受信号抑制，反之亦然。在行走过程中，这种抑制作用可能会变得很显著，因为在一个步周期的不同阶段，中间神经元的兴奋性和抑制性输入很可能会被诱发。节间中间神经元感受野的抑制区域从未被发现小于突触前局部中间神经元感受野的兴奋区域，并且可能是由几个脉冲发放的局部中间神经元的汇聚抑制性输入导致的。抑制性连接具有高度特异性：几个局部中间神经元可能会被一个也抑制节间中间神经元的特定刺激所激发，但只有一小部分前者是节间中间神经元抑制的原因。
