For sick person of PTSD , bad memory can sternly interrupt solar day - to - day sprightliness ; episodic memories of specific places , people , or effect can trigger off insuperable fear . scientist though have launch a way to direct specific memory in mouse and erase them using light , making it imaginable that conditions like PTSD might be matter of the preceding one day . Additionally , they proved a 40 - year - old theory about how episodic retentiveness are store and retrieved in the brain . The enquiry was led by Kazumasa Tanaka and Brian Wiltgen of University of California , Davis and the resultswere publishedin the journalNeuron .
Since the seventies , neuroscientists believe that episodic memories are stored and retrieved in different parts of the brain . interaction between the intellectual cortex and hippocampus need to work in concert in ordination to contribute the memories out of mental storage to be re - experienced by the mind . However , it has been difficult to test due to insufficient technology .
" The theory is that learning involves processing in the cerebral cortex , and the hippocampus multiply this blueprint of bodily function during retrieval , allowing you to re - experience the event , " Wiltgen said in apress expiration .
To see how this is accomplished , scientists used optogenetics , which let nerve activity to be studied with light . The work used mice with boldness cells that had been genetically modified to let out green fluorescence when activated . This fluorescence allowed them to chase retentiveness formation in the mouse ’s genius .
to boot , the nerve cell could be switched off and on through light from a fibre oculus cable manoeuver into its brain .
Next , the scientists need to give the mouse some bad memories to assess . While mice are generally funny and beloved to explore in new place , they lightly offend the mice in a particular cage for associate that localization with frightful memories . Rather than happily track down around the batting cage where the electric shocks were administered , the mouse would essentially shut down and remain still .
The fluorescent fixture cells allowed the researchers to identify which specific cells within the cerebral cortex and hippocampus were involved in find out and remembering those fearful experiences . When those particular cell in the genus Hippocampus were turn off with the light , the mice were n’t able to commemorate being afraid of the shock coop . However , turning off unrelated cells in the hippocampus did not dissemble the memory . This was fabulously important to support their claims .
" The lens cortex ca n’t do it alone , it needs input from the hippocampus , " Wiltgen continued . " This has been a central assumption in our field for a long time and Kazu ’s information provide the first direct evidence that it is true . " While it ’s not likely that this will be used to create an Eternal Sunshine of the Spotless nous - similar retention eraser , verifying how memories are stored and retrieved could open up possibilities for treatments for those experiencing memory loss or PTSD at some item down the route .
