Nearly 20 years ago, scientists developed ways to stimulate or silence neurons by shining light on them. This technique, known as optogenetics, allows researchers to discover the functions of specific neurons and how they communicate with other neurons to form circuits. Building on that technique, MIT and Harvard University researchers have now devised a way to achieve longer-term changes in neuron activity. With their new strategy, they can use light exposure to change the electrical capacitance of the neurons’ membranes, which alters their excitability (how strongly or weakly they respond…
