Years of research on mice proves that scientists can weaken or strengthen particular memories from the brain or outright delete inherited memories, the Guardian reported.
Scientists hope that the new discovery could potentially be used to help those with cognitive decline or post-traumatic stress disorder by removing fearful memories.
“We can use the same approach to selectively manipulate only the pathological fear memory while preserving all other adaptive fear memories which are necessary for our daily lives,” Jun-Hyeong Cho, co-author of the research from the University of California said.
The researchers used those mice to examine the pathways between the amygdala area of the brain responsible for emotional memories and the area that produces particular sounds. They played a series of low- and high-pitched tones that shocked the mice’s feet with electrodes on the high-pitched sounds.
“These mice are special in that we can label or tag specific pathways that convey certain signals to the amygdala, so that we can identify which pathways are really modified as the mice learn to fear a particular sound,” Cho said. “It is like a bundle of phone lines,” he added. “Each phone line conveys certain auditory information to the amygdala.”
The team then discovered it was possible to completely erase fearful or unwanted memories using a technique called optogenetics, while medication has been used for this purpose to remove the negative associations of some memories.
This technique involves using a virus to introduce genes into particular neurons in the brains of the mice that were involved in the “high-pitch” pathways.
Once the virus was inside the cells, the genes resulted in the production of proteins which responded to light, allowing researchers to control the activity of the neurons.
Taking mice with the fearful memories, the team exposed the neurons involved in the “high-pitch” pathway to low-frequency light – an approach which weakens the connections between the brain’s neuron transmitters.
“It permanently erases the fear memory,” Cho said. “We no longer see the relapse of fear.”
‘The fact that you can parcel out these memories and manipulate them in a predictable fashion is remarkable,’ Sumantra Chattarji, an expert on memory at the National Centre for Biological Sciences in Bangalore, India told New Scientist.
No comments:
Post a Comment