不 4L∠a sLcifretea, ex response was remarkably potentiated in either low Ca or in the presence of IBMX as well. The increased voltage responses of photoreceptors in low Ca wld definitely enhance- Be-velti The above two effects are in opposite signs. Therefore, whether light responses of the second-order neurons are potentiated or suppressed basically depends upon how much the saturation suppression is compensated by the increased voltage responses of photoreceptors 4 Passible explanation for differential modation by low Car可“2x from R- cones and G-cones to BCs reported that low Ca"suppressed the G-cone-driven responses of the cone horizontal cell more substantially than the R-cone-driven ones. This observation was accounted for by that the reduction in the synaptic strength between R-cones and cone honizontal cells due to saturation suppressioncoutdbecompensated to targerextenr by the more potentiate- cone signal in low Ca as compared to the G-cone signal [51]. This difference in compensation extent could时h↓y"drm modulation of R-cone and G-conce-driven BC responses(Fig. I and 2)/This explanation did not exclude other mechanisms that may involved in the above different effects of low Carsuch as R-cone andt econt\ mas operate aldimerent pathway for the signal input to cone eNBCs as it had een reported in Ltype horizontal cells. However, this point remaine te- ∠n-…=“ y而 2y(5.2