Morgan C, Nadelhaft I, de Groat W C
J Comp Neurol. 1981 Sep 20;201(3):415-40. doi: 10.1002/cne.902010308.
The central distribution of visceral primary afferent fibers from the pelvic nerve of the cast and the relationship of these fibers to preganglionic neurons of the sacral parasympathetic neurons (SPN) have been studied. Horseradish peroxidase (HRP) applied to the cut pelvic nerve was detected ipsilaterally in preganglionic neurons and dorsal root ganglion cells (segments S1-S3), and in central afferent projections to Lissauer's tract (LT), the dorsal columns, the dorsolateral funiculus, and spinal gray matter. The afferent projections were strongest in the region of the SPN (S1-S3) but extended far beyond its limits (e.g., LT was labeled from L4 to Cx7). In the transverse plane, collateral fiber bundles formed a thin shell around the dorsal horn predominantly within lamina I and expanded into terminal fields in the gray matter. The more prominent lateral collateral projection (LCP) extended into laminae V and VI, whereas the medial one (MCP) ended in the dorsal commissure. In longitudinal planes these projections exhibited a periodicity with an interval of approximately 200 micrometer. The distribution of afferent collateral projections overlaps the regions where many preganglionic neurons and their dendritic extensions are located, and also areas known to contain interneurons involved in visceral pathways. A differential distribution of afferents within the SPN was noted where a higher intensity was observed in proximity to those neurons located in laminae V and VI, which innervate the colon, and a lower intensity near neurons located in Lamina VII which innervate the bladder. This is consistent with the known spinal control of colon reflexes and the supraspinal control of bladder reflexes. The widespread rostrocaudal extent of the pelvic primary afferent projection is consistent with the necessity for the integration of somatic and autonomic elements from various levels of the lumbo-sacral-coccygeal spinal cord in the performance of pelvic visceral functions.
对去势动物盆神经内脏初级传入纤维的中枢分布以及这些纤维与骶副交感神经元（SPN）节前神经元的关系进行了研究。将辣根过氧化物酶（HRP）应用于切断的盆神经，在同侧的节前神经元和背根神经节细胞（S1 - S3节段）以及向脊髓胶状质（LT）、背柱、外侧索和脊髓灰质的中枢传入投射中均检测到了HRP。传入投射在SPN区域（S1 - S3）最强，但延伸范围远远超出其界限（例如，L4至Cx7节段的LT被标记）。在横切面上，侧支纤维束主要在I层围绕背角形成一层薄壳，并在灰质中扩展为终末场。更显著的外侧侧支投射（LCP）延伸至V层和VI层，而内侧侧支投射（MCP）终止于背连合。在纵切面上，这些投射呈现出约200微米间隔的周期性。传入侧支投射的分布与许多节前神经元及其树突延伸所在的区域重叠，也与已知含有参与内脏通路的中间神经元的区域重叠。在SPN内注意到传入纤维的差异分布，在支配结肠的位于V层和VI层的神经元附近观察到较高强度，而在支配膀胱的位于VII层的神经元附近强度较低。这与已知的结肠反射的脊髓控制和膀胱反射的脊髓上控制相一致。盆神经初级传入投射广泛的头尾延伸范围与在盆腔内脏功能中整合来自腰骶尾脊髓不同水平的躯体和自主神经成分的必要性相一致。
