大鼠视交叉上核内VIP、AVP及SOM样神经元的相互关系──免疫组化双重反应法研究

视交叉上核具有生物钟功能已为很多实验研究所证实，但其功能机制尚在探索之中。本实验采用双重免疫组织化学反应技术对大鼠视交叉上核内ＶＩＰ、ＡＶＰ及ＳＯＭ样三大神经元群之间的相互联系进行了观察．结果表明：（１）ＶＩＰ样扣结广泛分布于ＡＶＰ样神经元周围，数量最多、密度最大；而ＳＯＭ样扣结贴附于ＶＩＰ及ＡＶＰ样神经元的数量次之；（２）ＡＶＰ样扣结与ＶＩＰ样神经元之间，ＶＩＰ样扣结与ＳＯＭ样神经元之间也形成联系．上述发现为视交叉上核功能机制的研究提供了进一步的形态学依据．

THE ASSOCIATION OF VIP-, AVP-AND SOM-LIKE NEURONS IN THE RAT SUPRACHIASMATIC NUCLEUS:STUDY BY DOUBLE-IMMUNOLABELLING

The associations of neurons in the suprachiasmatic nucleus(SCN) of rats were examined by double-immunolabelling forvasoactive intestinal peptide (VIP), arginine vasopressin (AVP) and somatostatin (SOM). Ten adult male Sprague-Dawley(SD) rats were used in this study. Anti-VIP, anti-AVP and anti-SOM sera were used. The substrates in the peroxidase reaction were diaminobenzidine (DAB) and tetramethylbenzidine (TMB). The results showed that: 1. An extremely denseplexus of VIP-like varicose fibers distributed throughout the SCN. Most of them ended with terminal boutons on AVP-likeperikarya. Some of SOM-like varicose fibers ended on AVP-and VIP-like neurons. 2. AVP-like varicose fibers ended onVIP-like neurons. VIP-like fibers made boutons with SOM-like neurons. Based on findings of this study and others, we proposed that: (1) the principal light signal projection routes in the SCN was light signal→VIP-like neurons→AVP-like neurons→the other parts of the brain ; (2) another route of photic information transfered in the SCN perhaps exicted , as follows: light signal→VIP-like neurons→SOM-like neurons→AVP-and VIP-like neurons→the other parts of the brain; (3)AVP-like neurons may regulate VIP-like neurons through a feedback mechanism.