June 4, 2014
How to erase a memory –- and restore it: Researchers reactivate memories in rats
How to erase a memory –- and restore it: Researchers reactivate memories in rats
The study, published in the June 1 advanced online issue of the journal Nature, is the first to show the ability to selectively remove a memory and predictably reactivate it by stimulating nerves in the brain at frequencies that are known to weaken and strengthen the connections between nerve cells, called synapses.
File under “things likely to make someone insane”: first having a memory switched off, just long enough to make one wonder if it was even there in the first place, and then turning it back on. The memory was there, helping in the formation of core awareness and perception, and then it wasn’t. The brain adapts to its absence, and then is forced to readapt to its reappearance. That might make for a very unique variety of torture, an absolute crisis of identity.
This sort of rewiring is now possible, according to a study out this week in the journal Nature. And it doesn’t really take rewiring at all, just a beam of light. Using the relatively new techniques of optogenetics, in which animals are genetically engineered such that their brain tissue becomes sensitive to photo stimuli (lasers), it’s possible to quickly alter the neurological functioning of an animal by boosting the electrical potential between certain synapses. It’s a mechanism learned from algae, which alters its behavior in accordance with sunlight.
The good news is that memory-based torture isn’t the goal of this research (and this sort of research generally). What we’re after is the very nature of memory in the first place, just what it even is within the brain’s physiology. The effectiveness of these photogenic techniques is further evidence that memories are the result of strengthened connections between certain neurons, subtle depressions or channels that form memory-storing circuits. Silence these channels/circuits and the memory goes away; reinstate them and the memory returns.