Originally found on https://www.newscientist.com/article/2119423-memories-can-be-disconnected-and-it-could-help-those-with-ptsd/

People with post-traumatic stress disorder often get flashbacks that can be triggered by an innocuous smell or sound. Now a study that linked unrelated memories and separated them again, suggests that one day we may be able to decouple memories and prevent flashbacks in people with PTSD.

Individual memories are stored in groups of neurons – an idea first proposed by psychologist Donald Hebb in 1949. Only now are we developing sophisticated techniques for examining these ensembles of neurons.

To see whether two independent memories can become linked, Kaoru Inokuchi at the University of Toyama in Japan, and colleagues used a standard method for creating memories in mice. When mice are exposed to pain, they can learn to link this with associated stimuli, a taste, for example.

The team trained mice to form two separate fear memories. First, the mice learned to avoid the sugary taste of saccharine. Whenever they licked a bottle filled with saccharine solution, they were injected with lithium chloride, which induces nausea.

Disconnecting memories

A few days later, the same mice were taught to associate a tone with a mild electric shock. This caused the mice to freeze whenever they heard it, even if it wasn’t followed with a shock. They remembered the tone as a traumatic experience.

The team then linked these two unrelated memories. Whenever the mice licked saccharine, the researchers played the tone that scared them, so that eventually the mice began to freeze when they tasted the sugary flavor alone.

Written by Anil Ananthaswamy

For information on Drug-Free PTSD Treatment, contact us at Unique Mind Care.