巨细胞网状核与脊髓后角间的双向投射——HRP法和ARG法联合研究

The efferent fibers and afferent fibers between nucleus reticularis gigantocellularis and spinal cord of the rat:a combined study of HRP and ARG

动物经戊巴比妥钠麻醉,于立体定位仪上将内含20%HRP(注入20只大鼠)或100μci/μ1~3H-亮氨酸(注入12只大鼠)的微玻管插入巨细胞网状核(NGC),标记物注射持续45min。动物存活2 d(注入HRP)或1周(注入~3H-亮氨酸)后,动物深麻,灌注,脑干或脊髓冰冻切片,分别进行TMB呈色或D-19~b显影。结果显示:脊髓板层Ⅶ～Ⅷ内的HRP标记细胞较板层Ⅲ～Ⅴ和Ⅸ为多。在板层Ⅰ～Ⅵ,Ⅶ,Ⅷ和Ⅸ内可见散在的HRP标记终末。~H-亮氨酸注入NGC后,下行放射自显影标记终未在脊髓内出现的部位与上述HRP终未出现的部位基本一致。提示:NGC和脊髓间存在着双向投射关系,并且此种形态学方面的投射特点为NGC在疼痛方面反馈性调节功能提供理论依据。

Animals were anesthetized with sodium pentobarbitol and mounted in a stereotaxic instrument.Then the micropipe containing 20% HRP (for 20 rats)or 100 uci/ul ~3H-leucine (for 12 rats) was in-serted into nucleus reticularis gigantocellularis (NGC). The injection lasted 45 min. Two days afterbeing treated with HRP or 7 days after the injection of ~3H-leucine, animals were deeply anesthetizedand perfused;frozen sections of the brain stem and spinal cord were treated with TMB (HRP method)or developed with D-19 HC developer (ARG method). The results of the HRP method indicated thatmore HRP labeling cells were observed in laminae Ⅶ and Ⅷ than in laminae Ⅲ-Ⅴ and Ⅸ. The HRPlabeling terminal was observed in Ⅰ-Ⅵ, Ⅶ, Ⅷ and Ⅸ of C_2-C_5. Injections of ~3H-leucine into NGCproduced the descending autoradiographic labeling terminal in the same place where HRP terminal wasfound. The present results indicate that the efferent fibers and the afferent fibers between NGC andspinal cord serve as a feedback reflex circulation for pain control.