大鼠蓝斑内P物质、神经降压肽和生长抑素样神经元的上行投射

本实验采用HRP逆行追踪与免疫细胞化学相结合的方法,对大鼠蓝斑内P物质(SP)、神经降压肽(NT)、生长抑素(SOM)三种肽能投射神经元的纤维联系及其局部关系进行了探讨。结果证实:1.HRP注射至丘脑或尾壳核后,大鼠蓝斑内均可见到双标记神经元。2.存在SP样和NT样蓝斑—丘脑纤维,前者终止于丘脑腹后核和板内核,后者终止于丘脑板内核。3.蓝斑至尾壳核的投射呈SOM样免疫反应。4.蓝斑内三种肽能投射的起始和终止部位有所不同,其中SP样和NT样神经元主要位于蓝斑后部背侧区,其纤维终于丘脑;而SOM样投射神经元则见于蓝斑前部背侧区,纤维终止于尾壳核。上述肽能通路均为双侧性,而以同侧占优势。5.蓝斑内三种肽能单标记神经元中以NT样免疫反应阳性胞体最为丰富。以上结果表明;蓝斑上行性投射中除含去甲肾上腺素纤维外,还含有SP样、NT样和SOM样纤维,并存在一定的局部定位投射关系。

ASCENDING PROJECTIONS OF THE SUBSTANCE P-, NEUROTENSINAND SOMATOSTATIN-LIKE IMMUNOREACTIVE NEURONS IN THE LOCUS COERULEUS OF THE RAT

The projections and topographical organization of the substance P(SP), neurotensin(NT), and somatostatin(SOM)- like neurons of the locus coeruleus in the rat were studied by combined HRP tracing and PAP immunohistochemical method. The results were as follows: 1. Following injection of HRP into the thalamus or the caudateputamen nucleus and immunocytochemical processing of the brain sections, double labeled cell bodies were found in the locus coeruleus in all cases. 2. SP-like and NT-like fibers from the locus coeru eus to the thalamus were identified. The former terminated in the thalamic ventroposterior nucleus, the latter ended in the thalamic intralaminar nucleus. 3. Neurons projecting to the caudate-putamen from the locus coeruleus exhibited SOM-like immunoreactivity. 4. There were some differences of the origins and terminations of three kinds of peptidergic projections, the SP-like and NT-like cell bodies were located in the posterior part and dorsal divisions of the locus coeruleus and their fibers terminated in the thalamus; The SOM-like perikaryon were found in the anterior part and dorsal divisions of the locus coeruleus and the fibers terminated in the caudate-putamen nucleus. 5. Among the three kinds of single labeled peptidergic neurons, NT-like immunoreactive cell bodies were most numerous in the locus coeruleus. These results indicate that the ascending projections of the locus coeruleus, beside the wellknown noradrenergic fibers, also contain SP, NT and SOM-like components, their distribution exhibit some topographical organization.