US researchers 'hack' fly brains and control them remotely
A research team consisting of scientists from some of the top insitutes in the U.S. have demonstrated a wireless technology that allows neurons in a fly brain to be controlled in less than a second, an institutional press release said.
With advances in our understanding of how our brain works, scientists are looking for ways to tap into this functionality to achieve goals that were previously unthinkable. For instance, a research project funded by the National Science Foundation (NSF) and the Defense Advanced Research Projects Agency (DARPA) aims to develop a headset technology that can not only read the brain's neural activity but also write it for another individual.
Called Magnetic, Optical, Acoustic Neural Access (MOANA), the program aims to develop a wireless headset that can facilitate brain-to-brain communication in a nonsurgical manner. Jacob Robinson, an associate professor at Rice University is among the researchers working on the project, and his team has developed a method to hack fly brains wirelessly.
How did the researchers hack fly brains?
The research team used genetic engineering to express a special ion channel in flies' neuronal cells, which can be activated using heat. When the ion channel is activated, the flies spread out their wings, as they would do as part of their mating gesture.
To activate the channel at will, the researchers then injected the experimental flies with nanoparticles that could be heated by applying a magnetic field. The genetically modified flies were then introduced into an enclosure that had an electromagnet on top and a camera to capture the movements of the flies.
When the researchers activated the electromagnet, the electric field heated the nanoparticles, which activated the neurons, resulting in the flies spreading their wings, as seen in the short video below.
Analyzing the video from the experiments, the researchers also found that the time lapse between the activation of the electromagnet and the spreading of wings was less than half a second.
"By bringing together experts in genetic engineering, nanotechnology, and electrical engineering we were able to put all the pieces together and prove this idea works," said Robinson in the press release.
What happens next?
Robinson is confident that this ability to precisely activate cells will be helpful in studying the brain, developing brain communication technology as well as treating brain-related disorders.
The team is focused on developing technology that will help restore vision in people even if their eyes do not work. They aim to achieve this by stimulating parts of the brain that are associated with a vision to give a sense of vision in the absence of functional eyes.
"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 ways to go," Robinson added. "The long-term goal of this work is to create methods for activating specific regions of the brain in humans for therapeutic purposes without ever having to perform surgery."
The work done in collaboration with researchers at Brown University and Duke University was published in the journal Nature Materials.
Precisely timed activation of genetically targeted cells is a powerful tool for the study of neural circuits and control of cell-based therapies. Magnetic control of cell activity, or ‘magnetogenetics’, using magnetic nanoparticle heating of temperature-sensitive ion channels enables remote, non-invasive activation of neurons for deep-tissue applications and freely behaving animal studies. However, the in vivo response time of thermal magnetogenetics is currently tens of seconds, which prevents precise temporal modulation of neural activity. Moreover, magnetogenetics has yet to achieve in vivo multiplexed stimulation of different groups of neurons. Here we produce subsecond behavioural responses in Drosophila melanogaster by combining magnetic nanoparticles with a rate-sensitive thermoreceptor (TRPA1-A). Furthermore, by tuning magnetic nanoparticles to respond to different magnetic field strengths and frequencies, we achieve subsecond, multichannel stimulation. These results bring magnetogenetics closer to the temporal resolution and multiplexed stimulation possible with optogenetics while maintaining the minimal invasiveness and deep-tissue stimulation possible only by magnetic control.