In a innovative new study , researcher at theUniversity of California , San Diegoerased and then reactivated memories by excite neurons in the brains of genetically engineered rats with a serial of light heart rate that have been previously shown to strengthen or counteract the connections between brain cells . This is the first study to be able to directly show that the strengthening or weakening of these connexion , call synapsis , is theunderlying basisfor store . The field has been put out inNature .
Neurons communicate with each other via synapsis , which are the tiny gap between cells that allow the flow of information in the course of a chemic or electrical sign . Early researchfound that recapitulate electric stimulation of neuron within a brainiac region called the genus Hippocampus enhanced the ability of these cell to put across with neighbour . This process is call farsighted - term potentiation ( LTP ) , and it has long been suspected that this is the implicit in basis of memory formation . Despite tenner of research , however , no one has unequivocally demonstrated that this is the case .
For this study , a team of research worker lead by UCSD neuroscientist Roberto Manilow first mastermind rats so that their genius cells produced aflare sensitive proteinwhich could be activate by a pulse of light deliver by an optical fiber embed into the brain . They then used thisoptogeneticsto term the rats to associate pain with ocular stimulation by render light heart rate to certain neuronal populations and then shocking the dirty dog . The rats quickly start toassociatethe optical stimulant with pain and display fear responses when the neuron were have . The scientist were able to demonstrate telling star sign of LTP by seem atchemical changesin the neurons .
Next , the team cause the same neuron but with a different , humiliated - frequency sequence of calorie-free pulses that had beenpreviously demonstratedto reverse LTP by weakening the synaptic connections , which is jazz as long - term slump ( LTD ) . When the mice were give the optic arousal that they originally associated with pain they no longer elicited a fear reply , suggesting that the original memory was efface . The squad was able to then reactivate the memories by birth high - frequency sparkle pulses that triggered LTP , and then erase them again . “ We were playing with memory like a yo - yo , ” Manilow said in anews - handout .
The results of this study are therefore finally able to attest acausal linkbetween LTP , LTD and storage . “ We can make an fauna to have fear and then not have concern and then to have fear again by stimulating the nerves at relative frequency that tone up or weaken the synapsis , ” said lead generator Sadegh Nabavi in anews - dismission .
This discovery may also have app in the field of Alzheimer ’s research since , according to Manilow , the beta - amyloid protein fragment that builds up in the brainiac of Alzheimer ’s patients also weaken synapses in a similar fashion to how the dispirited - frequency stimulation in this discipline removed memories . “ So this lineage of inquiry could suggest way to interpose in this process,”he added .
