Changing Structure (IMAGE) University at Buffalo Caption A synapse formed by the auditory nerve in a normal mouse (blue, left), and in a mouse exposed to noise for a week (blue, right). Researchers say it's likely that synapses become enlarged in noise-exposed mice to create space for more vesicles -- small round structures that store chemicals used to deliver messages to the brain. Credit Amanda M. Lauer, Johns Hopkins University School of Medicine Usage Restrictions This image may only be used in conjunction with news reports covering the research in the associated press release. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.