Wenthold R J, Parakkal M H, Oberdorfer M D, Altschuler R A
Laboratory of Neuro-otolaryngology, National Institutes of Neurological and Communicative Disorders and Stroke, Bethesda, Maryland 20892.
J Comp Neurol. 1988 Oct 15;276(3):423-35. doi: 10.1002/cne.902760307.
Glycine appears to be a major inhibitory neurotransmitter in the cochlear nucleus. In order to determine more precisely the distribution of glycinergic synapses, we have studied the immunocytochemical distribution of the glycine postsynaptic receptor. Two monoclonal antibodies were used, Gly Rec Ab 2, which recognizes the 48kD polypeptide and Gly Rec Ab 7, which primarily recognizes the 93kD subunit of the glycine receptor complex. At the light microscopic level, glycine receptor immunoreactivity was found throughout the ventral cochlear nucleus with a punctuate distribution often found outlining large cell bodies. Indistinguishable patterns of staining were obtained with the two antibodies. Ultrastructural localization was done with Gly Rec Ab 7 because immunoreactivity remained after fixation with glutaraldehyde containing solutions. At the ultrastructural level, immunoreactivity was concentrated at postsynaptic sites on dendrites and cell bodies. In the anteroventral cochlear nucleus, neurons identified as spherical cells contained numerous inmunoreactive synapses on their cell bodies, whereas most immunoreactive synapses on stellate cells were on their proximal dendrites. In the posteroventral cochlear nucleus, neurons identified as octopus cells were immunoreactive on their cell bodies and proximal dendrites. In the granule cell layer, immunoreactivity was found only in the neuropile. Throughout the ventral cochlear nucleus, glycine receptor immunoreactivity was found postsynaptic to terminals containing flattened synaptic vesicles as well as those containing oval/pleomorphic synaptic vesicles.
甘氨酸似乎是耳蜗核中的一种主要抑制性神经递质。为了更精确地确定甘氨酸能突触的分布，我们研究了甘氨酸突触后受体的免疫细胞化学分布。使用了两种单克隆抗体，识别48kD多肽的甘氨酸受体抗体2（Gly Rec Ab 2）和主要识别甘氨酸受体复合物93kD亚基的甘氨酸受体抗体7（Gly Rec Ab 7）。在光学显微镜水平上，在整个腹侧耳蜗核中都发现了甘氨酸受体免疫反应性，其呈点状分布，常勾勒出大细胞体的轮廓。两种抗体获得的染色模式无法区分。由于在用含戊二醛的溶液固定后仍保留免疫反应性，因此使用甘氨酸受体抗体7进行超微结构定位。在超微结构水平上，免疫反应性集中在树突和细胞体的突触后部位。在前庭腹侧耳蜗核中，被鉴定为球形细胞的神经元在其细胞体上含有大量免疫反应性突触，而星状细胞上大多数免疫反应性突触位于其近端树突上。在耳蜗后腹侧核中，被鉴定为章鱼细胞的神经元在其细胞体和近端树突上具有免疫反应性。在颗粒细胞层中，仅在神经毡中发现免疫反应性。在整个腹侧耳蜗核中，在含有扁平突触小泡的终末以及含有椭圆形/多形性突触小泡的终末的突触后都发现了甘氨酸受体免疫反应性。
