Wireless technology can activate the brain circuits of fruit flies in under a second

Researchers from Brown University, Baylor College of Medicine, Rice and Duke University found that magnetic signals can be utilised to trigger targeted neurons that control the body position of fruit flies moving in an enclosure.

Professor in computer and electrical engineering and a member of Rice’s Neuroengineering Initiative, Jacob Robinson, stated that the new technology stimulates neural circuits approximately fifty times faster than formerly demonstrated technology for magnetic stimulation of neurons.

The researchers caused the flies to partially spread their wings, a common mating gesture, by using genetic engineering to express a unique heat-sensitive ion channel in neurons that stimulate this action. The researchers injected magnetic nanoparticles that could be heated with an applied magnetic field. They allowed the flies to move freely about an enclosed space on an electromagnet with an overhead camera watching. By altering the magnetic field in a specific way, the researchers could heat the nanoparticles and activate the neurons. The video from the experiment showed flies with the genetic modifications adopted the wing-spread posture within about half a second following the magnetic change.

Robinson stated that the ability to stimulate genetically targeted cells at precise times could aid studies of the brain, creating direct brain-machine communication technology and treating disease.

MOANA (magnetic, optical and acoustic neural access), a DARPA-funded project on which Robinson is the principal investigator, hope to create headset technology for wireless, nonsurgical, brain-to-brain communication. MOANA intends to develop headset technology that can “read,” or decipher, neural activity in one person’s visual cortex and “write,” or encrypt, that activity in another person’s brain. According to Rice, magnetogenetic technology is a case of the latter.

By stimulating sections of the brain linked with vision, Robinson’s team hopes to partially return vision to patients who are blind. The researchers hope to give patients a sense of sight even if their eyes are no longer intact.

Robinson stated: “To study the brain or to treat neurological disorders, the scientific community is searching for tools that are both incredibly precise, but also minimally invasive. Remote control of select neural circuits with magnetic fields is a holy grail for neurotechnologies. Our work takes an important step toward that goal because it increases the speed of remote magnetic control, closer to the brain’s natural speed. The long-term goal of this work is to create methods for activating specific brain regions in humans for therapeutic purposes without ever having to perform surgery. To get to the natural precision of the brain, we probably need to get a response down to a few hundredths of a second. So, there is still a way to go. We made progress because Charles Sebesta, the lead author, had the idea of using a new ion channel that was sensitive to the rate of temperature change. By bringing together genetic engineering, nanotechnology and electrical engineering experts, we could put all the pieces together and prove this idea works.”