引用

四足动物需要精确的机制来协调前肢和后肢的运动活动，人类也需要类似的机制来协调胳膊和腿的运动。脊髓本体神经元(PSNs)是协调这些机制的网络的主要组成部分。霍乱毒素(CTb)的b亚单位被单方注射到L1或L3节段，以标记上升和下降的固有脊椎通路。用光学显微镜或共聚焦显微镜检查标记细胞。向腰椎节段突出的细胞分布均匀，分布于双侧所有颈椎节段。然而，L1注射比L3注射有更多的细胞被标记。C2节段两侧约15%的细胞对钙维甲酸具有免疫反应性，少数(4%)对钙结合素具有免疫反应性。轴突从L1向颈节段突出，形成颈中间灰质和腹角的主要同侧突出。大量末梢集中在C7-8节段的腹侧运动核内，但对侧核神经分布稀疏。同侧VML中绝大多数(85%)轴突末端对囊泡性谷氨酸转运体2 (VGLUT2)有免疫反应，其余15%对囊泡性GABA转运体(VGAT)有免疫反应; many of these contained GABA and/or glycine. Inhibitory and excitatory terminals were also found in the contralateral VLM. Most of the terminals in the VLM made contacts with motoneurons. The major finding of this study is the existence of a substantial excitatory propriospinal pathway that projects specifically to the VLM. Motoneurons in the VLM supply muscles of the axilla therefore this pathway is likely to have a profound influence on the activity of the shoulder joint. This pathway may synchronise lumbar and cervical pattern generators and hence the coordination of locomotor activity in the fore- and hind limbs.