Functional morphologic study on NO (nitric oxide) -containing neurons.

一氧化氮（NO）是一种影响环境的气体自由基分子，在脊椎动物的某些活细胞中被发现合成。这种分子在身体的各种器官中具有多功能生理活性。特别是神经系统受到NO的影响，其对例如神经传递、突触可塑性、神经毒性和神经元老化具有各种作用。一氧化氮合成酶（NOS）对NO的合成起着动态调节作用。除了存在于正常脑中的组成型NOS（cNOS）之外，已知诱导型NOS（iNOS）响应于损伤或炎症而表达。因此，很明显，脑功能与两种类型的NOS合成的NO的产生有关。在本研究中，我们研究了发育中的大鼠脑中含NO神经元的个体发育方面的免疫组织化学和NADPH-黄递酶组织化学方法。两个突出的NO含神经元细胞群被发现，一个在脑桥和其他在下丘脑。随着胚胎的生长，含NO的神经元广泛分布在大脑的各个区域。用NADPH-黄递酶组织化学法结合轴突追踪法，观察了翼腭神经节含NO神经纤维的起源和向脑动脉的投射方式。本研究结果为NO在脑血管不同部位的药理和生理活性差异提供了神经解剖学基础，并在1995年7月由首席研究员在大津组织的国际研讨会上作了报告，该研讨会是国际脑研究组织会议的附属会议。

Nitric oxide (NO) , agasous radical molecule which affects the environment, has been discovered to be synthesized in certain living cells of vertebrates. This molecule has mutifunctional physiological activities in various organs of the body. The nervous system, in particular, is under the influence of NO with various roles on, for example, neurotransmission, synaptic plasticity, neurotoxicity and neuronal aging. The multiplicity of NO appears to be dynamically regulated by its synthesizing enzyme, nitric oxide-synthase (NOS). In addition to the constitutive NOS (cNOS) which is present in the normal brain, inducible NOS (iNOS) has been known to be expressed in response to injury or inflammation. It is therefore evident that the brain function is associated with the production of NO synthesized by both types of NOS.In the present study, we studeid the ontogenetic aspect of NO-containing neurons in developing brains of the rat by using immunohistochemical and NADPH-diaphorase histochemical methods. Two prominent NO-containing neuronal cell groups were found, one in the pons and the other in the hypothalamus. As embryos grow, NO-containing neurons were distributed widely throughout various brain regions. The details of such patterns of distribution of No-neurons were mapped at embryonic day 15 and day 19.The origin and the pattern of projection of NO-containing nerve fibers from the pterygopalatine ganglion to brain arteries were also examined by the NADPH-diaphorase histochemical method combined with axonal tracing methods. The result provided the neuroanatomical basis for differential pharmacologic and physiologic activities of NO in different parts of brain vessels.In addition, these data were presented in an international symposium organized by the head investigator on July, 1995 at Otsu, as a satellite symposium of the meeting of The International Brain Research Organization.