成年和发育中大鼠胼胝体轴突含生长抑素的免疫组织化学证据

IMMUNOHISTOCHEMICAL EVIDENCE FOR SOMATOSTATIN-CONTAINING AXONS IN THE CORPUS CALLOSUM OF ADULT AND DEVELOPING RATS

本实验用免疫组织化学ＡＢＣ法发现大鼠胼胝体内存在生长抑素免疫反应阳性轴突．此阳性轴突可见于生后不同发育阶段及成年大鼠的胼胝体内．出生时胼胝体内此轴突的数量很少；生后１周内其密度逐渐增高，至第２周初期达到高峰，此时胼胝体内可见大量生长抑素阳性轴突．然而，至第２周末，生长抑素阳性胶胝体轴突的密度已下降至接近成年时的水平，即仅有少量此纤维存在于胼胝体内。这些结果提示在大鼠早期生后发育过程中许多生长抑素阳性胼胝体轴突是暂时性的．结合本文作者等以往对成年和发育中大鼠和猫的与胼胝体联系的神经介质的研究结果，可以认为胼胝体中的活性物质是多样的，在哺乳动物大脑皮质发育中可能起着不同的作用。

Postnatal devlopment of somatostatin-immunoreative (SS-IR ) axons in rat corpus callosum was investigated by meansof immunohistochemistry (ABC method ). SS-IR axons were found in the corpus callosum of the rat from newborn throughadult. A few SS-IR axcons appeared in the corpus callosum of the newborn rat. The density of SS-IR callosal axons increasedduring postnatal week (PNW) 1 and peaked in early PNW 2. At early PNW 2, many SS-IR axons existed in the corpus callosum. However, the density of SS-IR callosal axons decreased rapidly to the adult level by the end of PNW 2. In adult, only a few SS-IR axons were seen in the corpus callosum. These results indicate that many SS-IR callosal axons are transitoryduring postnatal development of the rat. Our previous and present results on neurochemicals of callosal connections in adultand developing rat and cat suggested that callosal connections had a variety of neurotransmitters and these transmitters mayplay different roles in the development of mammalian cerebral cortex.(Figure 2 on plate 58)