Hemichannel-mediated and pH-based feedback from horizontal cells to cones in the vertebrate retina.

ABSTRACT:

Background

Recent studies designed to identify the mechanism by which retinal horizontal cells communicate with cones have implicated two processes. According to one account, horizontal cell hyperpolarization induces an increase in pH within the synaptic cleft that activates the calcium current (Ca(2+)-current) in cones, enhancing transmitter release. An alternative account suggests that horizontal cell hyperpolarization increases the Ca(2+)-current to promote transmitter release through a hemichannel-mediated ephaptic mechanism.

Methodology/principal findings

To distinguish between these mechanisms, we interfered with the pH regulating systems in the retina and studied the effects on the feedback responses of cones and horizontal cells. We found that the pH buffers HEPES an

SUBMITTER: Fahrenfort I 

PROVIDER: S-EPMC2699542 | biostudies-literature | 2009 Jun

REPOSITORIES: biostudies-literature