Synaptic transmission from horizontal cells to cones is impaired by loss of connexin hemichannels.

ABSTRACT: In the vertebrate retina, horizontal cells generate the inhibitory surround of bipolar cells, an essential step in contrast enhancement. For the last decades, the mechanism involved in this inhibitory synaptic pathway has been a major controversy in retinal research. One hypothesis suggests that connexin hemichannels mediate this negative feedback signal; another suggests that feedback is mediated by protons. Mutant zebrafish were generated that lack connexin 55.5 hemichannels in horizontal cells. Whole cell voltage clamp recordings were made from isolated horizontal cells and cones in flat mount retinas. Light-induced feedback from horizontal cells to cones was reduced in mutants. A reduction of feedback was also found when horizontal cells were pharmacologically hyperpolarized but was ab

SUBMITTER: Klaassen LJ 

PROVIDER: S-EPMC3139627 | biostudies-literature | 2011 Jul

REPOSITORIES: biostudies-literature