Ionic mechanisms underlying the center and surround responses of on-center bipolar cells in the carp retina.
Reversal potentials were measured for the center and surround responses of on-center bipolar cells in the carp retina. In the scotopic condition, the center response showed a reversal at 29 +/- 13mV, the surround response at 38 +/- 13 mV. The result suggests that both the center and surround responses were -53 +/- 11 mV and -59 +/- 11 mV, respectively. These responses were sensitive to the red light. It is therefore suggested that both the center and surround responses contributed by rods are mediated by changes in conductance of Na+ channels but in opposite ways. In the photopic condition, reversal potentials of the center and surround responses contributed by red cones are mediated by changes in conductance of K+ and/or Cl- channels, but in opposite ways. The responses in the mesopic condition showed the complex electrical properties as a consequence of interaction between the two ionic components described above.
D000818:Animals; D002347:Carps / Q000502:physiology*; D003118:Color Perception / Q000502:physiology; D003530:Cyprinidae / Q000502:physiology*; D004573:Electrolytes / Q000378:metabolism; D007473:Ion Channels / Q000502:physiology*; D008564:Membrane Potentials; D009431:Neural Conduction; D009474:Neurons / Q000502:physiology; D010775:Photic Stimulation; D010786:Photoreceptor Cells / Q000502:physiology; D012160:Retina / Q000502:physiology*; D014794:Visual Fields
D004573:Electrolytes; D007473:Ion Channels