Now, where did I put that memory?
Scientists at MIT, along with Stanford's Karl Deisseroth, MD, PhD, have shed light on the possibility of locating individual memories within the brain, down to the population of neurons involved.
In the study, published online today in Nature, investigators tagged neurons in mice during learning and then manipulated them to artificially generate a memory. A Boston.com article summarizes the method, which applied a neuroscience tool called optogenetics:
Researchers chose to test a simple kind of memory -- a fear memory. In one experiment, mice were put in a chamber, allowed to explore, and given a foot shock. The next time the mice were put in the same dangerous chamber, they remembered the unpleasant electric shock and froze, taking on a defensive stance. Researchers had, however, inserted a gene that [codes] for a light-sensitive protein into the cells involved in making a memory, and then tested what happened when they used light to activate those genes -- without putting the mice in the same chamber. They saw the freezing behavior, as if the mice were reliving the memory.
If you're happier left in the dark on some details from your past, don't worry: The mice research won't be able to be reproduced in humans anytime soon. And a kid with a laser pointer probably can't stop you dead in your tracks. But yet, as a researcher not involved in the study said, "turning on a memory is a really, really cool step."
Previously: Stanford researchers create light-responsive heart cells, Using optogenetics to build a biological pacemaker, Researchers induce social deficits associated with autism, schizophrenia in mice, Optogenetics’ pioneer calls for a new perspective on the future of medical research