Emery D G, Ito H, Coggeshall R E
J Comp Neurol. 1977 Mar 1;172(1):37-47. doi: 10.1002/cne.901720103.
This study shows that approximately 30% of the axons in the T11 and T12 ventral roots of the cat are unmyelinated. The unmyelinated axons fall into two categories. Slightly less than half are efferents from the spinal cord and slightly more than half arise from dorsal root ganglion cells. The efferent fibers are regarded as unmyelinated preganglionic sympathetics, the fibers of dorsal root ganglion origin are regarded as sensory. This organization of the T11-T12 ventral roots, which are part of the sympathetic outflow, is similar to that of cat ventral roots S3 and Cal, which are part of the parasympathetic outflow, but different from cat ventral roots L7 and S1, which are between the visceral outflows.
本研究表明，猫T11和T12腹根中约30%的轴突是无髓鞘的。这些无髓鞘轴突可分为两类。略少于一半是来自脊髓的传出纤维，略多于一半起源于背根神经节细胞。传出纤维被视为无髓鞘的节前交感神经纤维，起源于背根神经节的纤维被视为感觉纤维。作为交感神经传出部分的T11 - T12腹根的这种组织方式，与作为副交感神经传出部分的猫S3和尾骨腹根的组织方式相似，但与位于内脏传出之间的猫L7和S1腹根不同。
