Webber C L, Wurster R D, Chung J M
Exp Brain Res. 1979 May 2;35(3):395-406. doi: 10.1007/BF00236759.
Cat phrenic motoneurons, labeled by intradiaphragmatic injection of horseradish peroxidase, formed a tight cluster in the most ventral portion of the ventral horn in lamina IX of the lower cervical cord. Cell counts were symmetrically distributed for 17 to 21 mm along the longitudinal axis of the cord with a unimodal peak at the junction of segments C5 and C6. The phrenic nucleus was bilaterally organized on either side of the cord with anatomical symmetry and in no case was there evidence for the crossing of phrenic axons in the cord. Assessment of cellular geometry and intercellular relationships demonstrated that phrenic cell diameters approximated a normal distribution with a single peak at 26 mum while longitudinal cell lengths average 76 mum. Cells of different size were mixed randomly at all levels of the nucleus. The minimum distance between cells was about 10 mum and the maximum cell packing density approached 2 cells per 10(6) mum3. The results confirm the location of the cat phrenic nucleus, extend the knowledge of phrenic motoneuronal geometry, and provide an anatomical basis for the understanding of recruitment and synchronization phenomena within the phrenic nucleus.
通过膈内注射辣根过氧化物酶标记的猫膈运动神经元，在下颈髓第IX层腹角的最腹侧部分形成紧密的细胞簇。细胞计数沿脊髓纵轴在17至21毫米范围内呈对称分布，在C5和C6节段交界处有一个单峰。膈核在脊髓两侧呈双侧对称组织，且在任何情况下都没有证据表明膈神经轴突在脊髓内交叉。对细胞几何形状和细胞间关系的评估表明，膈细胞直径近似正态分布，在26μm处有一个单峰，而纵向细胞长度平均为76μm。不同大小的细胞在核的所有层面随机混合。细胞间的最小距离约为10μm，最大细胞堆积密度接近每10(6)μm3有2个细胞。这些结果证实了猫膈核的位置，扩展了对膈运动神经元几何形状的认识，并为理解膈核内的募集和同步现象提供了解剖学基础。
