Newton B W, Unger J, Hamill R W
Department of Anatomy, University of Arkansas for Medical Sciences, Little Rock 72205.
Neuroscience. 1990;37(2):471-89. doi: 10.1016/0306-4522(90)90415-z.
The immunohistochemical distribution of calcitonin gene-related peptide and somatostatin in rat lumbar spinal laminae VII-X was investigated using the peroxidase-antiperoxidase technique. Within L1,2 laminae VII and X, calcitonin gene-related peptide and somatostatin fibers demarcate the location of preganglionic sympathetic neurons in a similar fashion in either sex but somatostatin is distributed in a sexually dimorphic manner in the lumbosacral (L5-S2) spinal cord with the male rat containing more somatostatin fibers and neurons than females. Within the ventral horn (lamina IX), calcitonin gene-related peptide has a sexually dimorphic distribution. Calcitonin gene-related peptide varicose fibers are found within the sexually dimorphic male cremaster nucleus but are virtually absent in the female cremaster nucleus. Calcitonin gene-related peptide varicose fibers are nearly absent in the remainder of the male and female lamina IX: this area includes the other two known sexually dimorphic spinal motonuclei: the dorsomedial and dorsolateral nuclei. Virtually all motoneurons in the lumbosacral spinal cord which are not sexually dimorphic contain calcitonin gene-related peptide. However, calcitonin gene-related peptide containing motoneurons have a heterogeneous distribution within sexually dimorphic nuclei. Calcitonin gene-related peptide containing motoneurons within the male and female cremaster nucleus are extremely rare. Some motoneurons within the male and female dorsomedial and dorsolateral nuclei contain calcitonin gene-related peptide with the female dorsomedial and dorsolateral nuclei containing a greater percentage of calcitonin gene-related peptide-containing motoneurons (c. 50%) than males (c. 20%). Somatostatin fibers are preferentially located in sexually dimorphic nuclei of either sex and are distributed in a sexually dimorphic manner within these nuclei with males containing a greater amount of somatostatin fibers than females. The amount of somatostatin immunoreactivity is most dense in the medial aspect of the dorsolateral nucleus, dense in the dorsomedial nucleus, moderate in the cremaster nucleus, and sparse in the lateral portion of the dorsolateral nucleus. In addition, a small column of motoneurons, between the dorsomedial and dorsolateral nuclei at the L5 level, is outlined by somatostatin fibers in females but is absent in males. Somatostatin containing motoneurons were not observed within the lumbar sexually dimorphic nuclei of either sex.
采用过氧化物酶-抗过氧化物酶技术研究了大鼠腰髓VII-X层降钙素基因相关肽和生长抑素的免疫组化分布。在L1、2节段的VII层和X层内，降钙素基因相关肽和生长抑素纤维以相似的方式界定了节前交感神经元的位置，在两性中均如此，但生长抑素在腰骶（L5-S2）脊髓中的分布具有性别差异，雄性大鼠含有的生长抑素纤维和神经元比雌性更多。在腹角（IX层）内，降钙素基因相关肽具有性别差异分布。在具有性别差异的雄性提睾肌核内可发现降钙素基因相关肽的曲张纤维，而在雌性提睾肌核内几乎没有。在雄性和雌性IX层的其余部分，降钙素基因相关肽的曲张纤维几乎不存在：该区域包括另外两个已知的具有性别差异的脊髓运动核：背内侧核和背外侧核。腰骶脊髓中几乎所有无性别差异的运动神经元都含有降钙素基因相关肽。然而，含降钙素基因相关肽的运动神经元在具有性别差异的核内分布不均一。雄性和雌性提睾肌核内含有降钙素基因相关肽的运动神经元极其罕见。雄性和雌性背内侧核和背外侧核内的一些运动神经元含有降钙素基因相关肽，雌性背内侧核和背外侧核中含降钙素基因相关肽的运动神经元百分比（约50%）高于雄性（约20%）。生长抑素纤维优先位于两性具有性别差异的核内，并在这些核内呈性别差异分布，雄性含有的生长抑素纤维比雌性更多。生长抑素免疫反应性的量在背外侧核的内侧最密集，在背内侧核密集，在提睾肌核中等，在背外侧核的外侧稀疏。此外，在L5水平，背内侧核和背外侧核之间有一小列运动神经元，在雌性中由生长抑素纤维勾勒出轮廓，而在雄性中则不存在。在两性的腰段具有性别差异的核内未观察到含生长抑素的运动神经元。
