Researchers at MIT have developed a hat that can control the minds of mice by using wireless optogenetics. The hat is really two circuit boards and an antenna that is wired directly to the mouse’s brain to control the animal’s behavior with flashes of light. Optogenetics is an emerging scientific field where light is used to control the behavior of cells and even entire animals.
Optogenetics works by loading cells (typically, neurons) with a protein that is light sensitive. This protein acts as a gatekeeper of the cell. When the protein is exposed to the light, it opens up and allows ions to enter the neuron, causing it to fire. By introducing the protein to exact sports, scientists can turn on certain parts of the brain or even individual neurons. Having control of the brain, and particular neurons gives researchers the ability to guide behavior.
In the past, optogenetics was limited by the mechanism for delivering the light to the altered neurons. The mechanism of choice was an optic fiber, attached to a laser or an LED. However, this method had serious drawbacks including only being able to work with a few animals over short periods of time because the fibers can tangle and break. Applying this mechanism also requires handling the animals at the start of the experiment, which can cause the individuals stress and alter their behavior. While useful for experiments, and even used to turn mice into psychopaths with the flip of a switch, researchers felt there had to be a better way.
To improve the ability to utilize optogenetics for mind control, researchers at MIT led by Ed Boyden created an optogenetics hat that runs off of wireless power. Designed by Christian Wentz, a nearby transmitter that isn’t connected to the mouse generates a magnetic field that is detected by the antenna on a hat that the mouse wears. The magnetic field creates an electrical current that can power a set of 16 LEDs in the helmet. This provides the light that is needed to trigger the firing of the altered neurons in the mouse’s brain.
In Wentz’s first design of the hat, the capacitor discharged the stored power, causing the LEDs to light up, but in newer versions this was redesigned so that software in the hat causes the capacitor to store the energy when it is not needed. The system is similar to a power grid for regular electricity in that it stores extra energy when there is extra available, and lets it out when there is a need for it.
The mind control hat is controlled by a base-station that plugs into a USB port. Controlling the mouse from his laptop, Wentz programmed a blue light to pulse on only one side of the mouse’s motor cortex (the part of the brain that is responsible for movement). This caused the mouse to turn toward that side as Wentz steered it remotely.
The researchers report no detrimental effects on the mice used in the experiment for having worn the mind control hat. The device is about a gram in weight, and is electrically insulated from the mouse itself so it shuts down if it gets a single degree hotter than the mouse’s normal temperature. The hat is also removable, so on days when experiments were not being performed the mouse was able to go hatless.
The wireless application of optogenetic technology for mind and behavior control could be useful for studying a variety of neurological conditions from epilepsy to Parkinson’s disease. The paper describing this research was published in the Journal of Neural Engineering.
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