Brain pacemaker controls optogenetics

A miniature wireless implant could allow more efficient optogenetics in the human brain, according to a University of Arizona study.

The “brain pacemaker” is implanted under the scalp by way of a simple procedure similar to surgeries, and allows digital control over intensity and frequency of light being emitted to neurons.

University of Arizona biomedical engineering professor and lead author of the study Philipp Gutruf said: “The advantage with optogenetics is that you have cell specificity: You can target specific groups of neurons and investigate their function and relation in the context of the whole brain.

“We can also independently stimulate multiple places in the brain of the same subject, which also wasn't possible before.”

In optogenetics, researchers load specific neurons with proteins called opsins, which convert light to electrical potentials. When a researcher shines light on an area of the brain, it activates only the opsin-loaded neurons.

Early optogenetics involved sending light to the brain through optical fibres with test subjects physically tethered to a control station, and previous battery-free techniques were bulky and attached outside of the skull.

This new wireless, battery-free implant is powered by external oscillating magnetic fields and has advanced control over targeted neuron groups.

“This system has two antennas in one enclosure, which we switch the signal back and forth very rapidly so we can power the implant at any orientation,” Gutruf added.

“In the future, this technique could provide battery-free implants that provide uninterrupted stimulation without the need to remove or replace the device, resulting in less invasive procedures than current pacemaker or stimulation techniques.”

Optogenetic simulation can be used to restore movement in case of paralysis, or could turn off areas of the brain or spine that cause pain, eliminating dependence on painkillers.

Gutruf’s research paper on the subject was published in Nature Electronics.