大鼠固定脑双侧脑桥尾侧网状核间联系的研究-Dil荧光标记法

本文用Di1荧光染料作轴突示踪剂,主要在大鼠死后固定脑组织上研究双侧脑桥尾侧网状核间联系。结果发现:大量标记纤维聚集成小束,自一侧脑桥尾侧网状核越过中线至对侧同名核,标记纤维呈桔红色、强荧光,直径约1-2微米,纤维主要集中该核的腹侧区。当这些纤维达对侧网状结构内的脑桥尾侧网状部位,其中有些纤维分为上升、下降技。下降纤维行于两侧网状结构的内侧部,同侧约可追踪4-7毫米,对侧约2毫米左右,纤维在下降过程中逐渐减少。活体注射后,可见少量越过中线纤维,并在两侧网状结构内侧部见到少量纤维和散在的终末样纤维。双侧锥体束内均见大量标记纤维,除少数例子外,对侧荧光强度强于同侧。少量交叉纤维入对侧锥体束后入脑桥尾侧网状核。本文还对新近使用于神经解剖研究的荧光染料Dil的优、缺点进行了探讨。

BILATERAL CONNECTIONS OF THE NUCLEUS RETICULARIS PONTIS CAUDALIS IN FIXED BRAIN OF ADULT RATS WITHFLUORECENT LABELLING METHOD

To examine connections between the two neuclei reticularis pontis caudalis (RPC) in the fixed brain of adult rats, the fluorescent dye, Dil. was injected unilaterally into the RPC. Many labelled coarse fibers of a diameter 1-5 um were observed joining together to form fascicles crossing the midline from the ipsilateral RPC to the contralateral RPC. As these fibers approched the RPC, some of them divided into ascending or descending collaterals. Many labelled fiber bundles from RPC descended within the medial part of reticular formation. Fibers could be traced as far as 4-7 mm ipsilaterally and about 2 mm contralaterally, but the number of them was reduced in further caudal sections. In vivo study showed that some fibers were crossing, some labelled terminal-like fibers were dispersed in the medial part of reticular formation on both sides. There were also many labelled fibers in both pyramidal tracts, but the fluorescent intensity was heavier on the contralateral side than that on the ipsilateral side except few cases. A few fibers crossed into the contralateral pyramidal tract were traced into RPC on that side. The advantages and disadvantages of Dil. were dicussed.