Chronic nerve-related pain could one day be eased by targeting a gene – but first, we must be sure that the treatment won’t interfere with closely related genes that are vital for controlling heartbeat. The four HCN genes code for proteins that form ion channels in neurons. It is the flow of sodium ions through these channels that triggers the burst of electrical activity known as an action potential that prompts a neuron to send signals to other neurons. HCN4 is known to play a key role in making the heart beat faster, but the role of the other three is something of a mystery, says Peter McNaughton at the University of Cambridge.
