Head top unit
Last month we covered Kevin Warwick’s creation of a robot controlled remotely by living rat brain tissue. This month a similar project by a group at MIT has completed almost exactly the same task in reverse. Electrodes implanted in a rat’s brain have been used to remotely control the rat’s movements by delivering impulses of light directly in to the brain tissue. Until now a problem for this method has been the size of the batteries required to power the unit that sits on the rat’s head. This problem has been solved to some extent by using “wireless power”, which consists of placing a small magnetic coil on the head top unit and transmitting electricity via a magnetic field from a nearby magnetic coil.
Wirelessly powered and controlled optogenetics
The remote control addition to this project is the ground breaking element here. It has long been known that electric stimulation of the brain can illicit specific behaviours. More recently the field of optogenetics has emerged becoming Nature’s “method of the year” in 2010. Optogenetics involves the use of a gene for producing light-sensitive protein in algae which is tied to the promoter for another gene which identifies neurons that elicit a given behaviour such as sex, aggression or the flight response. The light sensitive protein itself (such as channelrhodopsin) then activates those neurons electrically when the light is on. The modified gene is then delivered in to the brain by a virus. The neurons that trigger a particular behaviour can then be activated at the flick of a switch just by shining light on the brain using an LED.
Believe it or not, the purpose of this research isn’t a macabre project to develop Frankenstein pets. The emerging fields of optogenetics and remote power transmission combined are likely to result in vast developments in the fields of neural prosthetics. Theoretically there are also endless possibilities for the management of mood disorders. Optogenetics will surely be a field I’ll be keeping my eye on.
The original paper is open-access for 30 days (PDF)
Wentz CT, Bernstein JG, Monahan P, Guerra A, Rodriguez A, & Boyden ES (2011). A wirelessly powered and controlled device for optical neural control of freely-behaving animals. Journal of neural engineering, 8 (4) PMID: 21701058
Via Ed Yong on Not Exactly Rocket Science
