In order to determine how nociceptive input conveyed by the C-fibers terminating in superficial lam-inae of the spinal cord reaches the wide dynamic range (WDR) cells in deeper dorsal horn, which functions as ascend-i...In order to determine how nociceptive input conveyed by the C-fibers terminating in superficial lam-inae of the spinal cord reaches the wide dynamic range (WDR) cells in deeper dorsal horn, which functions as ascend-ing projection pathway, the morphological features of some WDR cells in the deeper dorsal horn of the cat lumbar spinal cord were studied by intracellular injection of horseradish peroxidase and physiological characterization. One of the fully stained neurons with somata in lamina V and dendrites that entered lamina Ⅱ were examined by electron mi-croscopy. Immunogold staining of ultrathin sections through the labeled proximal dendrites in lamina Ⅱ revealed that these dendrites received numerous synapses from substance P and glutamate immunoreactive (IR) axons, which were considered originating from C-fibers. In addition, many GABA-IR terminals were found presynaptic to the labeled dendrites. The results, therefore, suggest that the information carried by primary afferent can be sent from the super-ficial dorsal horn to the deeper laminae through monosynaptic contacts between C-fiber terminals and the long dorsal dendrites of some WDR cells in the deeper laminae, and that GABAergic system is involved in postsynaptic control to modulate the transmission of nociceptive sensory information.展开更多
基金supported by the Youth Project of National Natural Science Foundation of China(No.31200836)the Natural Science Foundation for Colleges and Universities in Jiangsu Province+3 种基金China(No.12KJD320005)Zhen Xing Project/the Special Talent Fund of Dean of Xuzhou Medical CollegeJiangsu ProvinceChina(No.2012KJZ15)
基金Project supported by the State Science and Technology Commission and the National Natural Science Foundation of China.
文摘In order to determine how nociceptive input conveyed by the C-fibers terminating in superficial lam-inae of the spinal cord reaches the wide dynamic range (WDR) cells in deeper dorsal horn, which functions as ascend-ing projection pathway, the morphological features of some WDR cells in the deeper dorsal horn of the cat lumbar spinal cord were studied by intracellular injection of horseradish peroxidase and physiological characterization. One of the fully stained neurons with somata in lamina V and dendrites that entered lamina Ⅱ were examined by electron mi-croscopy. Immunogold staining of ultrathin sections through the labeled proximal dendrites in lamina Ⅱ revealed that these dendrites received numerous synapses from substance P and glutamate immunoreactive (IR) axons, which were considered originating from C-fibers. In addition, many GABA-IR terminals were found presynaptic to the labeled dendrites. The results, therefore, suggest that the information carried by primary afferent can be sent from the super-ficial dorsal horn to the deeper laminae through monosynaptic contacts between C-fiber terminals and the long dorsal dendrites of some WDR cells in the deeper laminae, and that GABAergic system is involved in postsynaptic control to modulate the transmission of nociceptive sensory information.
基金This work was supported by the National Brain Science Basic Research Program (No.G1999054000) and National Natural Science Foundation of China (No. 30100052, 30200077, 30325023).
