Exposure to high-intensity noises, even if they are not enough to cause damage to the ear, affect memory and learning processes, according to a study published in the journalBrain Research.
The researchers, from the Center for Pharmacological and Botanical Studies (Buenos Aires, Argentina), worked with rats between 15 and 30 days of age, which is equivalent to ages understoodbetween 6 years and adolescence of a human being. “We were able to determine that a single exposure to noise for two hours is enough to generate cellular damage and an alteration in behavior,” Laura Guelman, one of the authors, explained to DiCYT. The scientists observed a series of morphological changes in the nucleus of cells in the hippocampus, an area of the brain related to memory and learning processes.
Fifteen days after exposure to noise, between 95 and 97 decibels in intensity, the animals showed memory failures and adecrease in anxiety levels, something that according to Guelman is not positive: “Animals have a lower level of alert to danger, which would prevent them from escaping from a possible predator.”
Contrary to expectations, the damage was more evident in the rats that suffered a single exposure lasting two hours, than in those that were subjected to noise for two weeks, to two hours of noise per day. This could be because animals at this age are still developing their nervous system, and it has the ability to adapt and respond to injuries.
This work would be a first step in finding a drug that helps prevent these lesions in the hippocampus. “Unraveling the mechanisms that mediate between noise and cell damage could help find an agent that interferes with them,” explained the researcher.
