Ganglion cell adaptability: Does the coupling of horizontal cells play a role?

Abstract

Background: The visual system can adjust itself to different visual environments. One of the most well known examples of this is the shift in spatial tuning that occurs in retinal ganglion cells with the change from night and day vision. This shift is thought to be produced by a change in the ganglion cell receptive field surround, mediated by a decrease in the coupling of horizontal cells. Methodology/Principal Findings; To test this hypothesis, we used a transgenic mouse line, a connexin 57-deficient line, in which horizontal cell coupling was abolished. Measurements, both at the ganglion cell level and the level of behavioral performance, showed no differences between wild type retinas and retinas with decoupled horizontal cells from connexin 57-deficient mice. Conclusion/Significance: This analysis showed that the coupling and uncoupling of horizontal cells does not play a dominant role in spatial tuning and its adjustability to night and day light conditions. Instead, our data suggests that another mechanism, likely arising in the inner retina, must be responsible. Copyright © 2008 Dedek et al.