牛蛙视网膜内神经肽Y的免疫组织化学研究

目的 研究神经肽Y（neuropeptideY，NPY）免疫阳性反应在牛蛙视网膜特别是在内网层中的分布及其突触联系。方法 免疫荧光组织化学和包埋后胶体金免疫电镜定量分析技术。结果 在内核层最内侧区域一类胞体较大的无长突细胞呈较强的NPY免疫阳性反应（NPY—IR），胞体的突起呈3条带状分布。免疫电镜定量分析揭示：NPY—IR无长突细胞与未标记的无长突细胞突起（49．7％）和神经节细胞树突（49．3％）形成突触联系。NPY—IR的无长突细胞突起主要接受双极细胞的突触传人（86％），极少数接受未标记的无长突细胞的突触传入（14％）。结论 NPY主要分布于牛蛙视网膜的内侧区域，主要接受来自双极细胞的兴奋性神经递质——谷氨酸的调控。

Immunohistochemical analysis of neuropeptide Y in the Bullfrog Retina

Objective To investigate the distribution and synaptic connectivity of neuropeptide Y (NPY)-like immunoreactivity (IR) in Bullfrog retina, Rana Calesbeiana, especially in the inner plexiform layer. Methods Light microscopy immunofluorescence and post-embedding colloidal gold labeling electron microscopy techniques were employed in this study. Results NPY immunoreactivity was associated with a small population of amacrine cell bodies in the inner nuclear layer and cell processes, ramified with 3 distinct bands, in the inner plexiform layer. As for ultrastructure, quantitative analysis showed that NPY-IR amacrine cell processes were most often presynaptic to NPY negative amacrine cell processes (49.7%) and ganglion cell dendrites (49.3%). NPY-IR amacrine cells predominantly received synaptic input from bipolar cell axon terminals (86%), while a few input from other amacrine cell processes (14%). Conclusion NPY-IR in Bullfrog retina is mainly distributed in the inner part and predominately receives excitatory glutamate modulation from bipolar cells.