Thanks to a recent development in optigenetics research, mice are teaching us about our own brains… by letting us control theirs. Christian Wentz from MIT has designed a mind-controlling hat for mice; the contraption is built of a pair of circuit boards, an antenna, and some advancements in remote battery tech, which allows a set of flashing LEDs to control the neural impulses of lab mice.
Optigenetics is the a relatively new field of study; using a combination of genetics, virology and optics, researchers are able to instantaneously activate or silence specific groups of neurons within circuits using flashes of light. It works like this: Neurons are injected with a light-sensitive protein that, essentially, turns the cells into switches–no light equals off, flash of light equals on. An “on” switch in a neuron makes it fire, thereby creating an action in the brain’s neural network.
Being able to control which neurons fire and when allows researchers to investigate nearly limitless aspects of brain function. The field, though young, has far-reaching implications for science, as it can answer age-old questions and long-standing debates about how and when the brain does what, information necessary for treating diseases like Parkinson’s or developing work-around techniques that would allow for increased functionality in a damaged brain.
There have been issues, though, regarding the feasibility of devices used to create the flashes of light necessary to conduct research. A battery source powerful enough to control to panel of LEDs is both cumbersome and heat-generating–roadblocks for studying test subjects without interfering in their mobility. That’s where Christian Wentz’s invention comes in.
Previously, subject mice were tethered to fiber optic cables. The setup worked for controlling brain impulses but caused issues with the mouse’s mobility and the range of studies that could be conducted; cables get tangled, can easily break, and create obstructions to natural activity that affect study results. The new design, shown above, operates on a wireless transmitter that is located near the mouse; any time the hat is within range, the transmitter charges the 16-LED panel used to send optic charges into the gatekeeper proteins loaded into the mouse’s neurons.
Ed Boyden, one of the founders of optogenetics and the leader of this study, discusses the device and its potential.:
The problem is that light sources are quite energy-inefficient; LEDSs and lasers dissipate a lot of their energy in heat, so you need quite high currents or power levels in order to get them to go…. For these experiments, you need enormously high amounts of power but only for brief amounts of time, [so] the system stores the extra when there’s extra around and lets it out when there’s demand, like the power grid for regular electricity. If you’ve got a cable attached to an animal, that would essentially ruin the experiment. Here you can pop on this little tiny device and it’ll enable all sorts of things.
And though the device is infact very small, in terms of hat-to-mouse ratio it could be smaller.
The device is really small, and we have even smaller versions now, down to about a gram. Nearly all of the underlying technologies enabling this device are being improved daily… By riding technology development curves, the system described here may eventually be miniaturized to a few square millimetres.
Boyden’s study and Wentz’s design open up the possibility for less invasive and larger-scale studies, improvements in research that could put a kind of running start on developing treatments for diseases that impact neuron function.