Yazulla S, Studholme K M
Department of Neurobiology and Behavior, State University of New York, Stony Brook 11794-5230.
J Comp Neurol. 1991 Aug 1;310(1):1-10. doi: 10.1002/cne.903100103.
Recent works utilizing glycine-immunoreactivity (IR) and combined Golgi impregnation and 3H-glycine uptake autoradiography indicate that glycinergic interplexiform cells (IPC) may synapse upon cell bodies in the inner nuclear and ganglion cell layers in fish retina. This possibility was investigated with immunocytochemical techniques using presynaptic and postsynaptic markers for glycinergic neurons: a monoclonal antibody (mAb 7A) against the 93 kDa subunit of the strychnine-sensitive glycine receptor and a polyclonal antiserum against a glycine/BSA conjugate. Synaptic contacts onto the lateral and proximal surfaces of amacrine cell bodies and onto the distal surface of cells in the ganglion cell layer were identified with both probes. The contacts were rare with one contacted amacrine cell/section of 500 linear micron. Serial 1-micron sections were processed alternately for glycine and GABA antisera using postembedding techniques at the light microscopic level. Glycine-IR processes + boutons were apposed to GABA-IR cell bodies in 16 of 17 examples, indicating that the dendro-somatic contacts were onto GABA-immunoreactive amacrine cell bodies. In context of other published morphological data, we suggest that the dendro-somatic synapses were derived from glycinergic IPCs. Glycinergic IPCs receive input from GABAergic horizontal cells and, via a shunt conductance produced by the dendro-somatic contacts, may be involved in controlling the sensitivity, temporal, or spatial properties of amacrine cell responses to large field illumination.
近期利用甘氨酸免疫反应性（IR）以及联合高尔基染色和³H-甘氨酸摄取放射自显影技术的研究表明，甘氨酸能网间细胞（IPC）可能与鱼类视网膜内核层和神经节细胞层的细胞体形成突触。利用针对甘氨酸能神经元的突触前和突触后标记物的免疫细胞化学技术对这种可能性进行了研究：一种针对士的宁敏感型甘氨酸受体93 kDa亚基的单克隆抗体（mAb 7A）和一种针对甘氨酸/牛血清白蛋白偶联物的多克隆抗血清。两种探针均识别出与无长突细胞体的外侧和近端表面以及神经节细胞层细胞的远端表面的突触接触。这种接触很少见，每500线性微米的切片中有一个接触的无长突细胞。在光学显微镜水平，使用包埋后技术对1微米厚的连续切片交替进行甘氨酸和GABA抗血清处理。在17个例子中的16个中，甘氨酸免疫反应性突起+终扣与GABA免疫反应性细胞体相邻，这表明树突-胞体接触位于GABA免疫反应性无长突细胞体上。结合其他已发表的形态学数据，我们认为树突-胞体突触源自甘氨酸能IPC。甘氨酸能IPC接收来自GABA能水平细胞的输入，并且通过树突-胞体接触产生的分流电导，可能参与控制无长突细胞对大视野光照反应的敏感性、时间或空间特性。
