DISTRIBUTION OF SOMATIC AND VISCERAL PRIMARY AFFERENT-FIBERS WITHIN THE THORACIC SPINAL-CORD OF THE CAT
DISTRIBUTION OF SOMATIC AND VISCERAL PRIMARY AFFERENT-FIBERS WITHIN THE THORACIC SPINAL-CORD OF THE CAT
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DOI：
10.1002/cne.902300108
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发表时间：
1984-01-01
影响因子：
2.5
通讯作者：
CONNELL, LA
中科院分区：
文献类型：
--
作者：
CERVERO, F;CONNELL, LA
利用辣根过氧化物酶（HRP）通过躯体和内脏神经纤维的运输，研究了猫脊髓下胸椎段躯体和内脏初级传入纤维的终止模式。将HRP浓缩溶液应用于成年猫右侧大植神经中央端和左侧[胸]T9肋间神经中央端至少5小时。一些动物在氯氯蔗糖麻醉下保持HRP运输时间（长达53小时），而在巴比妥酸盐麻醉后恢复的动物中，允许更长的HRP应用和运输时间（4-5天）。在同侧背角的I、II、III、Iv和V层和同侧克拉克氏柱中发现了体细胞传入纤维和曲张（推测为终末）。体突密度在背角浅部特别高。在脊髓旁矢状面，可见成束的体细胞纤维从背根经背柱和利索束与背角相连。体细胞传入端呈中外侧体位排列，皮节腹侧的传入纤维末端位于内侧背角，皮节背侧的传入纤维末端位于外侧背角。通过单根脊神经的躯体投射的总长度为2又2/3节段，包括入口节段、整个吻侧节段和尾侧节段的三分之二。在脊髓的前尾轴观察到躯体投射位置的外侧向内侧移位。同侧背角I和V层可见内脏传入纤维和静脉曲张（推测为末端）。内脏投影到背角的密度明显低于躯体投影。内脏传入纤维经利索束到达背角，并加入沿背角外侧边缘的一束细纤维。明胶质（II层）似乎没有内脏传入纤维。这些结果讨论了内脏-躯体趋同到胸脊髓感觉通路的机制。
Transport of horseradish peroxidase (HRP) through somatic and visceral nerve fibers was used to study the patterns of termination of somatic and visceral primary afferent fibers within the lower thoracic segments of the cat''s spinal cord. A concentrated solution of HRP was applied for at least 5 h to the central end of the right greater splanchnic nerve and of the left [thoracic] T9 intercostal nerve of adult cats. Some animals remained under chloralose anesthesia for the duration of the HRP transport times (up to 53 h) whereas longer HRP application and transport time (4-5 days) were allowed in animals that recovered from barbiturate anesthesia. Somatic afferent fibers 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 fibers 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 were observed, with afferent fibers from the ventral parts of the dermatome ending in the medial dorsal horn and afferent fibers 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 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 fibers 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 fibers reached the dorsal horn via Lissauer''s tract and joined a lateral bundle of fine fibers that run along the lateral edge of the dorsal horn. The substantia gelatinosa (lamina II) appeared free of visceral afferent fibers. These results are discussed in relation to the mechanisms of viscerosomatic convergence onto sensory pathways in the thoracic spinal cord.