Hemichannel-mediated inhibition in the outer retina
Hemichannel-mediated inhibition in the outer retina
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DOI：
10.1126/science.1060101
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发表时间：
2001-05-11
期刊：
影响因子：
56.9
通讯作者：
Weiler, R
中科院分区：
文献类型：
--
作者：
Kamermans, M;Fahrenfort, I;Weiler, R
视网膜第一突触的一个基本特征是从水平细胞到视锥细胞的负反馈通路。在这个突触中，connexin26在靠近锥体谷氨酸释放位点的水平细胞树突上形成半通道。阻断这些半通道使水平细胞超极化，调节视锥细胞的Ca2+通道，并消除所有反馈介导的反应。我们提出了一种反馈机制，其中Ca2+通道的活性和随后锥体的谷氨酸释放由通过这些半通道的电流调节。因为通过半通道的电流取决于水平细胞的偏振，它们的活动调节了视锥细胞的输出。
An essential feature of the first synapse in the retina is a negative feedback pathway from horizontal cells to cones. Here we show that at this synapse, connexin26 forms hemichannels on horizontal cell dendrites near the glutamate release site of the cones. Blocking these hemichannels hyperpolarizes horizontal cells, modulates the Ca2+ channels of the cones, and abolishes all feedback-mediated responses. We propose a feedback mechanism in which the activity of the Ca2+ channels and the subsequent glutamate release of the cones are modulated by a current through these hemichannels. Because the current through the hemichannels depends on the polarization of the horizontal cells, their activity modulates the output of the cones.