Gradual Hearing Loss “Reorganises” Brain’s Sensory Areas And Impairs Memory (In Mice)

By Emma Young In 2011, a US-based study published in the Journal of the American Medical Association found that people with hearing loss were more likely to develop dementia. This alarming result prompted a number of follow-up studies, which have substantiated the link and further explored the risk. But the mechanism of how hearing loss raises this risk has not been clear. Now a new study, by a team at Ruhr University Bochum in Germany, offers an explanation. The researchers found that gradual hearing loss (the sort commonly experienced into older age) “profoundly” alters normal processes in the brain’s cortex and hippocampus, and that this impairs memory. This work was conducted on mice, not humans. But it provides useful new insights into what might happen in people. Sudden sensory loss is known to trigger widespread reorganisation of key brain areas. This “cortical plasticity” is an adaptive way of dealing with a challenge. If someone suddenly loses their vision, for example, areas of the cortex that were dedicated to vision can switch to processing touch and hearing data, enhancing these senses. Information from our senses plays a big part in the formation of our memories, so we have strong links between the sensory cortices and the hippocampus, our most important memory structure. The sudden loss of a sense can therefore also produce disruptive changes in the hippocampus — and memory impairments. Eventually, though, this settles, limiting the disruption to m...
Source: BPS RESEARCH DIGEST - Category: Psychiatry & Psychology Authors: Tags: Brain Perception Source Type: blogs