Rehder V
Institut für Tierphysiologie Freien Universität Berlin, Federal Republic of Germany.
J Comp Neurol. 1989 Jan 15;279(3):499-513. doi: 10.1002/cne.902790313.
A morphological description is given for the motoneurons underlying the proboscis extension reflex in the honey bee (Apis mellifera). Sensory neurons from the mandibles and labium were examined and their projection areas were related to those of the motoneurons. Motoneurons are located in the ventral part of the suboesophageal ganglion, have their somata in the hemiganglion ipsilateral to the filled nerve, and send prominent branches through identified ventral commissures into the contralateral hemiganglion. Motoneurons to the same muscle have parallel-running projections into the contralateral hemiganglion, often parallel-running neurites and show vast areas of dendritic overlap. Arborizations of motoneurons are not restricted to their neuromere of origin but invade adjacent neuromeres, resulting in regions of dendritic overlap of motoneurons to different muscles. Sensory fibers from the mouthparts terminate in medio- and mediolateral parts of the suboesophageal ganglion, where their arborizations overlap with projections from motoneurons. A few sensory fibers descend in ventral parts of the cervical connective. Although sensory neurons from the mandible are restricted to the ipsilateral hemiganglion, those of the labium also show contralateral branches. These observations are discussed in the context of the suboesophageal ganglion as a ganglion composed of the embryonic fusion of three single neuromeres.
本文给出了蜜蜂（意大利蜜蜂）喙伸展反射所涉及的运动神经元的形态学描述。研究了来自上颚和唇的感觉神经元，并将它们的投射区域与运动神经元的投射区域相关联。运动神经元位于咽下神经节的腹侧部分，其胞体位于与被填充神经同侧的半神经节中，并通过确定的腹侧连合发出明显的分支进入对侧半神经节。支配同一肌肉的运动神经元向对侧半神经节有平行的投射，通常有平行的神经突，并显示出广泛的树突重叠区域。运动神经元的分支并不局限于其起源的神经节段，而是侵入相邻的神经节段，导致支配不同肌肉的运动神经元的树突重叠区域。来自口器的感觉纤维终止于咽下神经节的中部和中外侧部分，其分支与运动神经元的投射重叠。少数感觉纤维在颈神经索的腹侧部分下行。虽然来自上颚的感觉神经元局限于同侧半神经节，但唇的感觉神经元也显示出对侧分支。本文在咽下神经节是由三个单一神经节段胚胎融合而成的神经节这一背景下讨论了这些观察结果。
