Pericytes under pressure: TRPC3 channels as gatekeepers of capillary flow

Intrinsic control of cerebral blood flow in response to intravascular pressure is traditionally attributed to smooth muscle cells in arterioles. However, in this issue of <i>Science Signaling</i>, Ferris <i>et al.</i> demonstrate that capillary constriction is caused by pressure-induced depolarization of pericytes, mural cells that encircle capillaries, and is mediated by TRPC3 cation channels, identifying the channel as critical for fine-tuning brain perfusion.