A team of researchers has managed to partially manipulate the memories of several laboratory mice, according to the journal Science . This work, in addition to helping neuroscientists better understand memory formation processes, could be useful in treating schizophrenia or post-traumatic stress symptoms.
“The question that interests us is: how does our brain visualize the world?” Explains Mark Mayford, one of the authors of the study. “If we can understand this, we can also find out what goes wrong in situations where we have inappropriate perceptions.”
The researchers, from the Scripps Research Institute (California), genetically modified the mice so that they could activate the neurons involved in the formation of specific memories when they were given clozapine, a drug that treats schizophrenia and that recreates past experiences.
The scientists wanted to see if reactivating memory with the drug interfered with the ability to generate new memories. For this they put the animals in a box with white and opaque walls. A day later, the same mice were injected with clozapine and placed in a strong-smelling box with checkered walls in which the animals received small electric shocks. When they were put back in the same box the next day, the mice did not show fear or anxiety, something that generally occurs when an environment reminds them of a traumatic experience. That is, the clozapine supplied before entering made them relive the experience of the white box, in which they did not suffer pain, and prevented them from generating the new memory.
In the second experiment, the mice received the drug during the stay in the second box, and not before. As a result, the animals were suddenly paralyzed, and behaved anxiously, effectively indicating that they were reliving the experience.
“When you’re learning something, you integrate the new knowledge with the old information, and this often makes it difficult to separate the memories,” Mayford explains. The brains of people with post-traumatic stress disorder or schizophrenia produce false perceptions or fears out of context. This work may guide future research for the development of drugs that can combat these conditions.
