Modulation of horizontal cell coupling in the vertebrate retina

视网膜是位于眼睛后部的一层薄薄的神经细胞，它将视觉世界的光线转化为大脑可以解释的信号。光感受器是视网膜中对光敏感的神经细胞，与双极细胞和水平细胞(HC)建立联系(突触)。双极细胞与无长突细胞和神经节细胞形成突触，后者产生突起(轴突)，作为视神经投射到大脑。在视觉系统的第一突触水平上，HCS通过强调视觉场景中的差异来提高视觉敏锐度。这是经济的：不需要对视觉空间中的每个点的绝对强度进行编码，只需要对视觉空间中的点(称为中心)和背景(称为环绕)之间的差异进行编码。

The retina is a thin sheet of nerve cells at the back of the eye that converts the light of the visual world into a signal interpretable by the brain. Photoreceptors are the light-sensitive nerve cells of the retina and make connections (synapses) with bipolar cells and horizontal cells (HCs). Bipolar cells make synapses with amacrine cells and ganglion cells, the latter giving rise to processes (axons) that project to the brain as the optic nerve. At the level of the first synapse of the visual system, HCs enhance visual acuity by emphasizing differences in the visual scene. This is economical: the absolute intensity need not be encoded for every point in visual space, only the difference between a point in visual space (called the centre) and the background (called the surround).