G protein-coupled receptor signalling potentiates the osmo-mechanical activation of TRPC5 channels.

TRPC5 is an ion channel permeable to monovalent and divalent cations that is widely expressed in different tissues. Although implicated in the control of neurite extension and in the growth cone morphology of hippocampal neurons, as well as in fear-related behaviour, the mechanisms by which TRPC5 is activated remain poorly understood. TRPC5 is known to be activated downstream of Gq-coupled receptors and by membrane stretch, and since there is evidence that mechanical stress may directly activate Gq-coupled receptors, we examined the relationship between the activation of TRPC5 by the type 1 histamine receptor and osmotic stress.