Scientists discover that the emotions of painful memories … – Pulzo

This is suggested by a study of guinea pigs in Japan and the United States and published in the British scientific journal Nature.

Photo: Open Road Magazine.

“This property (investment) memory is used clinically to treat” mental illness, “however, the neural mechanisms and brain circuits authorizing these changes in emotional register remains completely unknown, “the researchers emphasize beforehand.

The purpose of the study is to decipher these underlying processes, opening the way to new clues to cure diseases such as depression or posttraumatic stress disorders. The same “also validates the success of current psychotherapy,” he told AFP research director Susumu Tonegawa.

This work, the result of close collaboration between the Japanese Riken Institute and the Massachusetts Institute of Technology (MIT) United States, are based on a new control technology brain through light, called “optogenetics” to better understand what happens when we remember good and bad times and if you can modify the (positive or negative) value associated a memory.

The results demonstrate that the interaction between the hippocampus part of the brain that plays a central role in memory, and the amygdala, a group of neurons that would be kind of storage chamber positive and negative reactions, it is more flexible than previously thought.

To reach these conclusions, the researchers injected a protein sensitive to light 2 groups of male mice alga. In this way they were able to follow the formation of an inscription in memory in real time, that reactivated at will through light pulses.

Some rodents were allowed to play with females in order to create a memory whose connotations were positive, while their comrades, however, they applied a nasty shock.

In a second step, the scientists made them relive these memories artificially subjecting them to simultaneously experience opposite: the pleasantly stimulated mice received an electric shock, while the others were surprised to find females

The new experience was overcome by the initial excitement.. “We did a test in the first cage and the original fear was gone,” describes Susumu Tonegawa, a Nobel Prize for medicine in 1987.

However, this phenomenon was observed only acting on the hippocampus, context sensitive surrounding, whereas it was not possible to influence the amygdala.

The researchers, who had already published work on inscriptions in memory of false memories in mice, hope their findings valence change positive to negative (Attraction to repulsion) and vice versa, will advance medical research on diseases of post-traumatic disorders or depressive type, which particularly affect the military.

In the future, Tonegawa aspires to “control neurons with a wireless technology without intrusive tools such as electrodes and potentially able to increase the number of positive memories about the negative. “

still remains to prove that this reversal of emotions associated with a memory works same way in humans as in mice, although we know that memory processes (associated with memory) are conserved throughout the evolution of species.

In a commentary published by Nature, researchers Tomonori Takeuchi and Richard Morris of the University of Edinburgh (Scotland) consider that this study throws new light on the mechanisms of memory, but indicate the limits of optogenetics in the field.