Ophthalmology Commons^™

Swelling And Eicosanoid Metabolites Differentially Gate Trpv4 Channels In Retinal Neurons And Glia., Daniel A. Ryskamp, Andrew O. Jo, Amber M M. Frye, Felix Vazquez-Chona, Nanna Macaulay, Wallace B. Thoreson, David Križaj

Journal Articles: Ophthalmology

Activity-dependent shifts in ionic concentrations and water that accompany neuronal and glial activity can generate osmotic forces with biological consequences for brain physiology. Active regulation of osmotic gradients and cellular volume requires volume-sensitive ion channels. In the vertebrate retina, critical support to volume regulation is provided by Müller astroglia, but the identity of their osmosensor is unknown. Here, we identify TRPV4 channels as transducers of mouse Müller cell volume increases into physiological responses. Hypotonic stimuli induced sustained [Ca(2+)]i elevations that were inhibited by TRPV4 antagonists and absent in TRPV4(-/-) Müller cells. Glial TRPV4 signals were phospholipase A2- and cytochrome P450-dependent, …