Cervero F, Connell L A
J Comp Neurol. 1984 Nov 20;230(1):88-98. doi: 10.1002/cne.902300108.
Transport of horseradish peroxidase (HRP) through somatic and visceral nerve fibres was used to study the patterns of termination of somatic and visceral primary afferent fibres within the lower thoracic segments of the cat's spinal cord. A concentrated solution of HRP was applied for at least 5 hours to the central end of the righ greater splanchnic nerve and of the left T9 intercostal nerve of adult cats. Some animals remained under chloralose anaesthesia for the duration of the HRP transport times (up to 53 hours) whereas longer HRP application and transport times (4-5 days) were allowed in animals that recovered from barbiturate anaesthesia. Somatic afferent fibres and varicosities (presumed terminals) were found in laminae I, II, III, IV, and V of the ipsilateral dorsal horn and in the ipsilateral Clarke's column. The density of the somatic projection was particularly high in the superficial dorsal horn. In parasagittal sections of the cord, bundles of somatic fibres were seen joining the dorsal horn from the dorsal roots via the dorsal columns and Lissauer's tract. A medio-lateral somatotopic arrangement of somatic afferent terminations was observed, with afferent fibres from the ventral parts of the dermatome ending in the medial dorsal horn and afferent fibres from the dorsal parts of the dermatome ending in the lateral dorsal horn. The total rostro-caudal extent of the somatic projection through a single spinal nerve was found to be of 2 and 2/3 segments, including the segment of entry, the entire segment rostral to it and two-thirds of the segment caudal to it. A lateral to medial shift in the position of the somatic projection was observed in the rostro-caudal axis of the cord. Visceral afferent fibres and varicosities (presumed terminals) were seen in laminae I and V of the ipsilateral dorsal horn. The density of the visceral projection to the dorsal horn was substantially lower than that of the somatic projection. Visceral afferent fibres reached the dorsal horn via Lissauer's tract and joined a lateral bundle of fine fibres that run along the lateral edge of the dorsal horn. The substantia gelatinosa (lamina II) appeared free of visceral afferent fibres. These results are discussed in relation to the mechanisms of viscero-somatic convergence onto sensory pathways in the thoracic spinal cord.
利用辣根过氧化物酶（HRP）通过躯体和内脏神经纤维的运输，来研究猫脊髓胸段下部躯体和内脏初级传入纤维的终末模式。将HRP浓溶液应用于成年猫右侧大内脏神经和左侧第9肋间神经的中枢端至少5小时。一些动物在HRP运输期间（长达53小时）一直处于水合氯醛麻醉状态，而从巴比妥类麻醉中恢复的动物则允许更长时间的HRP应用和运输（4 - 5天）。在同侧背角的I、II、III、IV和V层以及同侧的克拉克柱中发现了躯体传入纤维和曲张体（推测为终末）。躯体投射在背角浅层的密度特别高。在脊髓的矢状旁切片中，可见一束束躯体纤维从背根经后索和 Lissauer 束进入背角。观察到躯体传入终末有中 - 外侧的躯体定位排列，来自皮节腹侧部分的传入纤维终止于背角内侧，来自皮节背侧部分的传入纤维终止于背角外侧。发现通过单一脊神经的躯体投射在 rostro - caudal 方向上的总范围为2又2/3个节段，包括进入节段、其上方的整个节段以及其下方节段的三分之二。在脊髓的 rostro - caudal 轴上观察到躯体投射位置有从外侧向内侧的移动。在同侧背角的I层和V层中可见内脏传入纤维和曲张体（推测为终末）。内脏向背角的投射密度明显低于躯体投射。内脏传入纤维通过 Lissauer 束到达背角，并加入一束沿着背角外侧边缘走行的细纤维束。胶状质（II层）似乎没有内脏传入纤维。结合胸段脊髓感觉通路中内脏 - 躯体汇聚的机制对这些结果进行了讨论。
