Hearing Loss Impairs Synaptic Plasticity and Memory Function in Mice

The brain makes use of sensory information in order to form memories. Loss of hearing has an impact on the aging brain, as suggested by the correlation between onset of age-related deafness and onset of dementia. While it is possible that this reflects common processes of neurodegeneration, as age-related deafness appears to result from loss of neural connections between sensory hair cells and the brain, studies such as this one provide evidence for deafness to cause greater loss of function in areas of the brain associated with memory formation. Brain structures that are essential for the acquisition and encoding of complex associative memories, such as the hippocampus, use spatial sensory information both to generate metric representation of navigable space and to create robust and long-lasting records of spatial experience. The latter is enabled by hippocampal synaptic plasticity, and it has been shown that visuospatial, olfactospatial, and audiospatial experience can be used by the hippocampus to create spatial memories. Studies of the consequences of loss of visual input and blindness have shown that adaptation occurs as a consequence of extensive reorganization of the cortex that reflects both changes in the affected primary sensory cortex and in other primary and associative sensory areas. One aspect of this that has received little attention is how the cortex and hippocampus functionally adjust to initial loss of input from a specific sensory modality....
Source: Fight Aging! - Category: Research Authors: Tags: Daily News Source Type: blogs