Saito T, Kondo H, Toyoda J
J Gen Physiol. 1981 Nov;78(5):569-89. doi: 10.1085/jgp.78.5.569.
On-center bipolar cells in the dark-adapted carp retina were divided into four types (A, B, C, and D) on the basis of response wave forms, spectral response properties, and electrical membrane properties. Type A and B cells responded to a spot of light with a transient depolarization followed by a plateau, whereas the response of type C and D cells were approximately rectangular in shape. The center and surround responses of type A cells had maximum spectral response of approximately 525 nm in the lower mesopic range; the polarity of both responses was reversed at positive membrane potentials as the membrane was depolarized by extrinsic current. The center and surround responses of type D cells had a maximum spectral response of approximately 625 nm in the mesopic or photopic range; the polarity of both responses was reversed at membrane potentials that were more negative than those at the dark level. The results suggest that the center and surround responses mediated by rods are generated by changes in sodium conductance, but in opposite ways; whereas those mediated by red cones are generated by changes in potassium and/or chloride conductances. In type B and C cells, which probably receive inputs from both rods and/or green cones as well as red cones, the center responses were composed of the two ionic mechanisms described above. The surround responses of many type B and C cells were dominated by only one ionic mechanism with a negative reversal potential, but in some type B cells the surround responses were resulted from two ionic mechanisms similar to those of the center responses.
在暗适应的鲤鱼视网膜中，依据反应波形、光谱反应特性和电膜特性，将中心双极细胞分为四种类型（A、B、C和D）。A 型和 B 型细胞对光点的反应是先出现短暂的去极化，随后出现平台期，而 C 型和 D 型细胞的反应近似矩形。A型细胞的中心和周边反应在较低的中间视觉范围内，最大光谱反应约为525nm；当膜被外源电流去极化时，在正膜电位下两种反应的极性都会反转。D型细胞的中心和周边反应在中间视觉或明视觉范围内，最大光谱反应约为625nm；两种反应的极性在比暗水平时更负的膜电位下反转。结果表明，由视杆细胞介导的中心和周边反应是由钠电导的变化产生的，但方式相反；而由红色视锥细胞介导的反应是由钾和/或氯电导的变化产生的。在可能同时接受视杆细胞和/或绿色视锥细胞以及红色视锥细胞输入的B型和C型细胞中，中心反应由上述两种离子机制组成。许多B型和C型细胞的周边反应仅由一种具有负反转电位的离子机制主导，但在一些B型细胞中，周边反应是由与中心反应类似的两种离子机制产生的。
