Can you Cut and Paste A Memory?

Do we have the ability to cut and paste a memory? To take away the stimulus, the feelings, the pain out of a distant thought. Rats sure can; or at least the researchers modifying them are able to.

In a recent study published in the journal Nature, researchers at the UC San Diego School of Medicine have discovered ways of altering an animal's cognitive memories and subsequent interactions by erasing and reactivating memories in rats. Using genetically modified rats who are particularly sensitive to light, researchers were able to use optical pulses known to weaken and strengthen synapse connections in order to make a negative memory vanish, and just as suddenly reappear.

"We can form a memory, erase that memory and we can reactivate it, at will, by apply a stimulus that selectively strengthens or weakens synaptic connections" senior author and professor of neurobiology at UCSD, Roberto Malinow says.

Using negative memory reinforcement, researchers strengthened memory connections through high-frequency light pulses and an electrical shock applied to the rats' feet. Once establishing the connection within the rats' minds, wherein the stimulus would hint at an impending electrical shock, the rats began to exhibit fearful behavior when exposed to the optical stimulus.

However, when stimulating these same nerves with low-frequency optical pulses, the rats no longer responded to high-frequency stimulation with fear-suggesting that the pain-association memory had been altogether erased.

But when reexposed to the high-frequency pulses in absence of the shocks, the rats once again exhibited fearful behavior which indicated the retrieval of the lost painful memory.

Translating this research into clinical approaches for the future, Malinow and his fellow researchers hope that this will pave the way towards a potential cure for degenerative neurological disorders such as Alzheimer's.

"Since our work shows that we can reverse the processes that weaken synapses , [one day soon] we could potentially counteract some of the beta amyloid's effects in Alzheimer's patients" Malinow said.

Although Alzheimers' degeneration is not caused by optical light pulses, but rather an accumulation of beta amyloid peptide in the brain, the physiological effects and forgetful responses are nearly identical in every way. And if researchers are able to recreate past memories in rats, humans are only right around the corner.