Clark R D
J Comp Neurol. 1976 Nov 15;170(2):267-77. doi: 10.1002/cne.901700210.
Physiological and behavioural effects of separation from the soma were examined in isolated arborization and isolated axon segments of an identified motor neuron in the Polynesian field cricket, Teleogryllus oceanicus. The identified neuron, the contralateral dorsal longitudinal motor neuron of the metathoracic ganglion (CDLM), has an arborization most of which lies contralateral to its soma within the ganglion. Midline lesions in the ganglion separated CDLM into a distal segment composed of the axon and most of the arborization, and a proximal segment made up of the remaining arborization, neurite and soma. Isolated axonal segments were produced by cutting the nerve containing the CDLM axon. The function of the neuron-muscle system composed of CDLM, its pre-synaptic inputs, and its innervated muscle bundle was examined in contrl and experimentally operated animals. Extracellular recording assessed function in the axon. Electrical or tactil stimulation was used to excite pre-synaptic inputs to the CDLM arborization. Intracellular recording determined changes in post-synaptic potentials and miniature end-plate potentials in the muscle bundle innervated by CDLM. Normal axonal conduction, competence to respond to pre-synaptic input, neuron-muscle transmission, and miniature end-plate potential appearance can remain in the isolated arborization preparation. Physiological viability is longer in the cricket isolated arborization than in other insect distal segments described. Survival times of axonal conduction and the competence of the isolated arborization to respond to pre-synaptic input are roughly correlated with disappearance of the whole distal segment at 100 or more postoperative days. A naturally-occurring breakdown of the metathoracic dorsal longitudinal muscles in Teleogryllus eventually prevents measurements of post-synaptic potentials and miniature end-plate potentials. Normal post-synaptic function mediated by the distal arborization is maintained up to this breakdown, to a maximum of 44 days postoperative. The distal axonal segment of CDLM degenerates physiologically within four days postoperative, a time course approximating that of degeneration in vertebrate peripheral nerve distal axons.
在太平洋折翅蠊（Teleogryllus oceanicus）一个已鉴定的运动神经元的孤立树突分支和孤立轴突段中，研究了与胞体分离后的生理和行为效应。这个已鉴定的神经元是后胸神经节的对侧背纵运动神经元（CDLM），其树突分支大部分位于神经节内与其胞体相对的一侧。神经节中的中线损伤将CDLM分为一个由轴突和大部分树突分支组成的远端段，以及一个由其余树突分支、神经突和胞体组成的近端段。通过切断包含CDLM轴突的神经来制备孤立轴突段。在对照动物和实验操作动物中，研究了由CDLM、其突触前输入和其支配的肌束组成的神经元 - 肌肉系统的功能。细胞外记录评估轴突的功能。电刺激或触觉刺激用于激发对CDLM树突分支的突触前输入。细胞内记录确定由CDLM支配的肌束中突触后电位和微小终板电位的变化。在孤立树突分支制备中，正常的轴突传导、对突触前输入作出反应的能力、神经元 - 肌肉传递以及微小终板电位的出现都可以保留。蟋蟀的孤立树突分支的生理活力比所描述的其他昆虫远端段更长。轴突传导的存活时间以及孤立树突分支对突触前输入作出反应的能力与术后100天或更长时间整个远端段的消失大致相关。太平洋折翅蠊后胸背纵肌的自然退化最终阻止了突触后电位和微小终板电位的测量。由远端树突分支介导的正常突触后功能在这种退化之前一直保持，最长可达术后44天。CDLM的远端轴突段在术后四天内发生生理退化，其时间进程与脊椎动物外周神经远端轴突的退化相似。
