神经营养素-4在成年猴脑中的分布特征及其与成体中枢神经系统的功能关系

背景神经营养素-4(NT-4,Neurotrophin -4)在神经系统的发育和成体中均起重要作用,不仅对某些特定亚群神经元的存活、增殖、分化及轴突可塑性有一定的调节作用,而且对某些神经元的生存也是必需的.但这些资料大多来源于体外实验,其在体内的作用尚不十分清楚,NT-4在体内的分布也少见报道,在高等灵长类猴脑的研究尚未见报道.目的为探讨NT-4在成年灵长类动物猴脑的分布及为进一步研究NT-4与成体中枢神经系统的功能关系提供了有用的形态学依据.设计用PBS代替一抗的实验对照.地点和材料实验在昆明医学院神经科学研究所实验室完成.动物来自中科院昆明动物研究所的成年雄性恒河猴(体质量平均6 kg)7只.方法采用氯氨酮肌肉注射麻醉,Zamboin's液心脏灌注固定,取脑组织各部位行冷冻切片,厚25μm.免疫组织化学SP法,抗体为兔抗NT-4多克隆抗体.主要观察指标光镜下于猴脑的不同部位观察NT-4-IR阳性物(呈棕色串珠状、丝状或颗粒状).对照实验用0.05 mol/L PBS代替一抗行免疫组化染色.结果NT-4-IR(Neurotrophin -4 immunoreactive)分布于大脑皮层Ⅲ～V层的部分神经元胞体及突起以及白质内少量的神经胶质细胞;小脑皮质及白质内的部分神经元;海马CA1、CA2、CA3区的部分神经元;此外豆状核、尾状核、脑桥核、前庭神经核、薄束核、契束核、副神经核等可见散在阳性反应细胞及交织成网的纤维.结论NT-4-IR广泛地分布于猴脑的多种组织和细胞,提示其功能可能涉及不同类型的神经元及可能的非神经元.

Distribution characteristics of neurotrophin-4 in the brain of adult rhesus and its relation with the functions of mature central nervous system

BACKGROUND: Neurotrophin -4(NT-4) plays an important role in the development and maturity of nerve system, which not only has certain adjustment reactions in the survival, proliferation and differentiation of some specific subgroup neurons, and the plasticity of neurite, but also a necessity to the existence of some neurons. However, most of the data were from experiments in vitro and its mechanism in vivo is still not well established, and the reports about the distribution of NT-4 in vivo could hardly be seen as well. There was no such report about the research in advanced Primates,monkey brain.OBJECTIVE: To discuss the distribution of NT-4 in the brain of adult Primates animal, monkey, and to provide an useful morphological gist for further researches in NT-4 as well as its relationship with the functions of mature central nerve system.DESIGN: A case-control study with PBS instead of primary antibody.SETTING and MATERIALS: The study was oompleted in the Laboratory of Neurological Science of Kunmin Medical University. Animals were 7 adult male rhesus obtained from Kunmin Animal Institution of China Scientific Academy with a mean body weight of 6 kg.METHODS: Ketamine was injected into muscles for anesthesia, and Zamboin' s solution was used in cardiac perfusion for fixation. Each part of cerebral tissue was taken for frozen sections with a thickness of 25 μm. Immunohistochemical technique SP method was introduced. Antibody was anti-rabbit NT-4 polyclonal antibody.MAIN OUTCOME MEASURES: NT-4 immunoreactive(IR) positive substances(in brown rosary, thread or granule shapes) in different sites of the brain were observed under optical microscope. Control study: 0. 05 mol/L of PBS was used to replace the primary antibody for immunohistochemical staining.RESULTS: NT-4-IR distributes on some neuron somas and umbos in cerebral cortex Ⅲ to V layer as well as a few of gliocytes in white substance, some neurons in cerebellar cortex and white substance, some neurons in hippocampal CA1, CA2 and CA3 regions. Besides, scattered IR positive cell and intertexture fibres could be seen at lenticular nucleus, caudate nucleus, pontine nucleus,vestibular nucleus, cuneate nucleus, gracile nucleus and accessory nucleus.CONCLUSION: NT-4-IR widely distributes in multiple tissues and cells in the brain of rhesus, which suggests its function might be related to different types of neurons and some non-neurons as well.