Haifa U. mice memory manipulation could work on humans
"We were able, for the first time, to cause mice to assign a negative value to an event that never took place."
By MAAYAN JAFFE-HOFFMANMice [Illustrative](photo credit: INGIMAGE)
University of Haifa researchers manipulate memories in mice, say could apply to humans, tooA team of University of Haifa researchers have succeeded in implanting emotions in mice that were never experienced.“We were able, for the first time, to cause mice to assign a negative value to an event that never took place, and accordingly, to remember a feeling that was not experienced in reality,” said PhD student Haneed Kayyal, who led the study with postdoctoral fellow Adonis Yiannaks.In a three-part study, the scientists identified a neural pathway in the brain that determines whether a particular taste will have a positive or negative emotional value (impacting future consumption), and to use these neurons to erase or transplant memories that were never experienced in reality.Since these neural pathways are highly similar across mammals, including mice and humans, the researchers believe the study will be applicable in people, too.“The findings will allow us to explore in the future how a variety of psychiatric illnesses can be treated, ranging from eating disorders that have too-powerful or too-weak ‘emotional engravings’ in response to eating experiences and to dealing with emotional traumas such as PTSD, which do not allow the emotional value of an experience to be eradicated,” Prof. Kobi Rosenblum from the Sagol Department of Neurobiology at the University of Haifa, who oversees the PhD students, explained.Rosenblum has long been studying how the brain labels sensory memories as positive or negative, based on the understanding that although people are naturally born with a preference for certain flavors, for example, these innate preferences can be changed by a learning process.In the first part of this experiment, the researchers gave the mice something sweet to taste and associated it with a general feeling of discomfort, in this case abdominal pain. After repeating this several times, the mice avoided eating the sweet taste.The team concurrently investigated the brain activity of mice during the association of a sweet taste with abdominal pain and found “neuronal activation in the insular cortex in the brain, an area involved in complex brain functions, which projects to the basolateral amygdala, which is located in the medial prefrontal cortex and is involved in the formation of emotional memories,” a release explained.The basolateral amygdala is activated during anxious states.
Second, the team examined the necessity of this neural pathway to generate negative values by preventing the transmission of neural information between the two brain regions during learning. When the pathway was silenced, the mice did not remember the negative experience, and continued eating the sweet taste, despite it causing them discomfort.“The findings showed the importance and necessity of the neural pathway that we found, whose silencing prevented the mice from creating a memory for the experience they had been through,” the researchers said in a release.Finally, the team exposed a third group of mice to the same sweet taste and immediately activated the same specific nerve cell population that was activated following the consumption of this taste, when they experienced malaise, but without any sensory experience of discomfort. Two days later, these mice also avoided consuming the sweet taste, as if they knew it would cause them abdominal pain, although they did not experience any unpleasant sensations.The study was published in the Journal of Neuroscience.