Burrows M, Newland P L
Department of Zoology, University of Cambridge, England.
J Comp Neurol. 1993 Mar 15;329(3):412-26. doi: 10.1002/cne.903290311.
The relationships between the morphology and receptive fields of local and intersegmental interneurons that process mechanosensory information from a hindleg of the locust have been analysed. Sensory neurons from tactile hairs project to ventral areas of neuropil in the metathoracic ganglion where they form a 3-dimensional somatotopic map of a hindleg. By contrast, sensory neurons from a proprioceptor at the femoro-tibial joint (the femoral chordotonal organ) project to lateral and more intermediate areas of neuropil and have no branches in the most ventral regions of neuropil. Particular local and intersegmental interneurons respond to stimulation of specific arrays of hairs on a hindleg, or to movements of particular joints. Their receptive fields are defined, in part, by the patterns of excitatory, monosynaptic connections made by these afferents. Each interneuron has a characteristic receptive field and a characteristic morphology defined by its array of branches in the regions of neuropil containing the projections of the afferents that provide its monosynaptic inputs. Interneurons with inputs exclusively from tactile hairs have branches in the most ventral regions of neuropil, while those with exclusively proprioceptive inputs have branches only in more intermediate levels of neuropil. Interneurons with extensive receptive fields from tactile hairs also have extensive areas of branching within the ventral neuropil. Interneurons with receptive fields restricted to particular regions of the leg have branches restricted to the ventral region of neuropil containing the projections of afferents from that part of the leg. Thus, interneurons with inputs only from hairs on the tarsus have branches in the posterior region of neuropil corresponding to the projections of the tarsal afferents, while interneurons with receptive fields on the femur have branches in more anterior regions of neuropil corresponding to the projections of the femoral hair afferents. Interneurons with receptive fields on the tibia have branches in neuropil between the tarsal and femoral projections.
对处理蝗虫后足机械感觉信息的局部和节间中间神经元的形态与感受野之间的关系进行了分析。来自触觉毛的感觉神经元投射到后胸神经节神经纤维网的腹侧区域，在那里它们形成后足的三维体表定位图。相比之下，来自股胫关节处一个本体感受器（股弦音器）的感觉神经元投射到神经纤维网的外侧和更中间的区域，并且在神经纤维网最腹侧区域没有分支。特定的局部和节间中间神经元对后足上特定毛发阵列的刺激或特定关节的运动作出反应。它们的感受野部分由这些传入神经形成的兴奋性单突触连接模式所定义。每个中间神经元都有一个特征性的感受野和一种特征性的形态，其形态由其在神经纤维网区域内的分支阵列所定义，该区域包含提供其单突触输入的传入神经的投射。仅从触觉毛接收输入的中间神经元在神经纤维网最腹侧区域有分支，而仅从本体感受器接收输入的中间神经元仅在神经纤维网更中间的层面有分支。具有来自触觉毛的广泛感受野的中间神经元在腹侧神经纤维网内也有广泛的分支区域。感受野局限于腿部特定区域的中间神经元，其分支局限于神经纤维网的腹侧区域，该区域包含来自腿部该部分传入神经的投射。因此，仅从跗节上的毛发接收输入的中间神经元在神经纤维网的后部区域有分支，对应于跗节传入神经的投射，而在股骨上有感受野的中间神经元在神经纤维网更靠前的区域有分支，对应于股部毛发传入神经的投射。在胫骨上有感受野的中间神经元在跗节和股部投射之间的神经纤维网中有分支。
