Auditory‐evoked potentials to changes in sound duration in urethane‐anaesthetized mice

• Published in: The European journal of neuroscience Vol. 50; no. 2; pp. 1911 - 1919
• Main Authors: Lipponen, Arto, Kurkela, Jari L. O., Kyläheiko, Iiris, Hölttä, Sonja, Ruusuvirta, Timo, Hämäläinen, Jarmo A., Astikainen, Piia
• Format: Journal Article
• Language: English
• Published: France Wiley Subscription Services, Inc 01.07.2019
• Subjects: Animal models; auditory evoked potentials; Cortex (auditory); Cortex (temporal); Ethyl carbamate; Evoked potentials; Mismatch negativity; mouse model; Sound; Speech; temporal feature; mismatch negativity; mouse model; auditory evoked potentials; temporal feature
• ISSN: 0953-816X; 1460-9568
• DOI: 10.1111/ejn.14359

Spectrotemporally complex sounds carry important information for acoustic communication. Among the important features of these sounds is the temporal duration. An event‐related potential called mismatch negativity indexes auditory change detection in humans. An analogous response (mismatch response) has been found to duration changes in speech sounds in rats but not yet in mice. We addressed whether mice show this response, and, if elicited, whether this response is functionally analogous to mismatch negativity or whether adaptation‐based models suffice to explain them. Auditory‐evoked potentials were epidurally recorded above the mice auditory cortex. The differential response to the changes in a repeated human speech sound /a/ was elicited 53–259 ms post‐change (oddball condition). The differential response was observable to the largest duration change (from 200 to 110 ms). Any smaller (from 200 to 120–180 ms at 10 ms steps) duration changes did elicit an observable response. The response to the largest duration change did not robustly differ in amplitude from the response to the change‐inducing sound presented without its repetitive background (equiprobable condition). The findings suggest that adaptation may suffice to explain responses to duration changes in spectrotemporally complex sounds in anaesthetized mice. The results pave way for development of a variety of murine models of acoustic communication. Electrophysiological responses recorded from the auditory cortex of mice indicated detection of rare sounds differing in duration from frequent sounds. The differential response was not specific to change but could be explained by the lower presentation rate of the rare than frequent sounds. Forty‐five percentage decrease in duration of spectrotemporal sounds was required for neural indication of change detection. The results can be utilized in the future mice models of statistical learning.