Nanowires recording neuronal activity

A team led by engineers at the University of California San Diego has developed nanowires that can record the electrical activity of neurons in fine detail. The team believe the new technology could one day serve as a platform to screen drugs for neurological diseases and enable researchers to better understand how single cells communicate in large neuronal networks.

Researchers can uncover details about a neuron’s health, activity and response to drugs by measuring ion channel currents and changes in its intracellular potential. Existing techniques are very sensitive but destructive — they can break the cell membrane and eventually kill the cell. They are also limited to analyzing only one cell at a time.

The new nanowire technology is nondestructive and can simultaneously measure potential changes in multiple neurons.

The device consists of an array of silicon nanowires densely packed on a small chip patterned with nickel electrode leads that are coated with silica. The nanowires poke inside cells without damaging them and are sensitive enough to measure small potential changes that are a fraction of or a few millivolts in magnitude. Researchers used the nanowires to record the electrical activity of neurons that were isolated from mice and derived from human induced pluripotent stem cells. These neurons survived and continued functioning for at least six weeks while interfaced with the nanowire array in vitro.