Laboratory for Neuroinformatics, Riken Brain Science Institute, Wako, Saitama, 351-0198, Japan.
J Physiol Sci. 2012 Sep;62(5):359-75. doi: 10.1007/s12576-012-0220-0. Epub 2012 Jul 7.
In the vertebrate retina, feedback from horizontal cells (HCs) to cone photoreceptors plays a key role in the formation of the center-surround receptive field of retinal cells, which induces contrast enhancement of visual images. The mechanism underlying surround inhibition is not fully understood. In this review, we discuss this issue, focusing on our recent hypothesis that acidification of the synaptic cleft of the cone photoreceptor terminal causes this inhibition by modulating the Ca channel of the terminals. We present evidence that the acidification is caused by proton excretion from HCs by a vacuolar type H(+) pump. Recent publications supporting or opposing our hypothesis are discussed.
在脊椎动物的视网膜中，来自水平细胞（HCs）的反馈对锥体光感受器在视网膜细胞的中心-环绕感受野的形成中起着关键作用，这诱导了视觉图像的对比度增强。环绕抑制的机制尚不完全清楚。在这篇综述中，我们讨论了这个问题，重点介绍了我们最近的假设，即通过调节末端的钙通道，锥体光感受器末端突触小间隙的酸化导致这种抑制。我们提出了证据表明，这种酸化是由通过液泡型 H+泵从 HCs 中排出质子引起的。讨论了支持或反对我们假设的最新出版物。
