An immunocytochemical study of glycine receptor and GABA in laminae I- III of rat spinal dorsal horn
An immunocytochemical study of glycine receptor and GABA in laminae I- III of rat spinal dorsal horn
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DOI：
10.1523/jneurosci.13-06-02371.1993
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发表时间：
1993-06
期刊：
影响因子：
--
通讯作者：
K. Mitchell;R. Spike;A. Todd
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文献类型：
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作者：
K. Mitchell;R. Spike;A. Todd
为了提供有关甘氨酸在大鼠背角浅层三层中的功能以及甘氨酸和 GABA 在该区域突触处可能共存的信息，我们进行了一项联合研究，包括使用甘氨酸受体单克隆抗体进行预包埋免疫细胞化学，以及使用固定 GABA 抗血清进行包埋后免疫细胞化学。所有三个层中的轴突和轴体突触以及层 II 中的树突突触均存在甘氨酸受体样免疫反应性。尽管形成轴突突触的轴突通常位于免疫反应性轴突突触的突触前（因此可能含有甘氨酸），但轴突突触本身并不表现出甘氨酸受体样免疫反应性。甘氨酸受体免疫反应性突触突触前的许多特征显示出类似 GABA 的免疫反应性。这些结果表明，甘氨酸在 I-III 层的各种类型的突触中充当突触后抑制递质，并且它可能与该区域的许多突触中的 GABA 共存。然而，虽然甘氨酸和 GABA 都可能在轴轴突触处释放，但甘氨酸要么不充当这些突触的递质，要么它作用于本研究中使用的抗体无法识别的非典型受体。
In order to provide information about the function of glycine in the superficial three laminae of the rat dorsal horn and the possible coexistence of glycine and GABA at synapses in this region, we have carried out a combined study involving preembedding immunocytochemistry with a monoclonal antibody to the glycine receptor and postembedding immunocytochemistry with antiserum to fixed GABA. Glycine receptor-like immunoreactivity was present at axodendritic and axosomatic synapses in all three laminae, and at dendrodendritic synapses in lamina II. Although axons that formed axoaxonic synapses were often presynaptic at immunoreactive axodendritic synapses (and thus probably contained glycine), the axoaxonic synapses themselves did not show glycine receptor-like immunoreactivity. Many of the profiles that were presynaptic at glycine receptor-immunoreactive synapses showed GABA- like immunoreactivity. These results suggest that glycine acts as a postsynaptic inhibitory transmitter at various types of synapses in laminae I-III, and that it may coexist with GABA at many synapses in this region. However, it appears that while glycine and GABA may both be released at axoaxonic synapses, either glycine does not act as a transmitter at these synapses, or else it acts at an atypical receptor that was not recognized by the antibody used in this study.