Funakoshi K, Kadota T, Atobe Y, Nakano M, Tsukagoshi M, Goris R C, Kishida R
Department of Anatomy, Yokohama City University School of Medicine, Yokohama, Japan.
Brain Res Bull. 2000 Aug;52(6):547-52. doi: 10.1016/s0361-9230(00)00295-1.
Neuropeptides in the motor nerves innervating the red and white muscles of the goldfish Carassius auratus were examined. In the tonic red muscles, varicose nerve endings immunoreactive for both calcitonin gene-related peptide and substance P were found spread over the surface of the muscle fibers, but in the twitch white muscles only scattered nerve endings immunoreactive for calcitonin gene-related peptide were found. At the electron microscopic observation, dense electron products immunoreactive for calcitonin gene-related peptide and for substance P (SP) were detected in the motor nerve endings making synapses on the muscle fibers of the red muscles. In the spinal cord, all of the motor neurons showed immunoreactivity to calcitonin gene-related peptide, but the motor neurons immunoreactive for substance P were restricted to the ventrolateral group that has been shown to project predominantly to the red muscles. These results suggest that the motor neurons innervating the red and white muscles of the goldfish are distinct in their neuropeptide content. The present study also raises the possibility that SP might be related to the unique physiological properties of the tonic type red muscles, probably by direct binding to the acetylcholine receptors.
对支配金鱼（Carassius auratus）红色和白色肌肉的运动神经中的神经肽进行了研究。在强直性红色肌肉中，发现对降钙素基因相关肽和P物质均有免疫反应的曲张神经末梢散布在肌纤维表面，但在快速收缩的白色肌肉中，仅发现了对降钙素基因相关肽有免疫反应的散在神经末梢。在电子显微镜观察中，在与红色肌肉的肌纤维形成突触的运动神经末梢中检测到了对降钙素基因相关肽和P物质（SP）有免疫反应的致密电子产物。在脊髓中，所有运动神经元均显示出对降钙素基因相关肽的免疫反应性，但对P物质有免疫反应的运动神经元仅限于腹外侧组，该组已被证明主要投射到红色肌肉。这些结果表明，支配金鱼红色和白色肌肉的运动神经元在神经肽含量上有所不同。本研究还提出了一种可能性，即SP可能与强直性红色肌肉的独特生理特性有关，可能是通过直接与乙酰胆碱受体结合。
