Dopamine in the Nucleus Accumbens Signals Salience of Auditory Deviance

How the brain signals prediction errors for non-rewarding, yet significant, sensory events remains a central question. While the cortical Mismatch Negativity provides a well-known signature for deviance detection, the contribution of subcortical dopamine remains unclear. This study tested the hypothesis that phasic dopamine in the nucleus accumbens encodes the salience associated with the violation of an ongoing statistical regularity. Using fiber photometry in freely moving rats, we contrasted an auditory oddball paradigm with a many-standards control. Deviant stimuli elicited a significantly amplified dopamine response compared to standard stimuli. Crucially, this dopamine response enhancement was absent in the control condition, demonstrating that the nucleus accumbens dopamine responds specifically to rule violation rather than mere stimulus rarity. The long latency of this signal (~500 ms) relative to the cortical Mismatch Negativity argues against a direct role in the initial detection of deviance. Instead, our findings support a model in which subcortical dopamine acts as a distinct salience signal, operating in parallel to cortical deviance detection, to evaluate unexpected events and guide subsequent behavioral adjustments. Supplementary Material File (maintext2.docx) - Download - 1.38 MB Information & Authors Information Version history Peer review timeline Published European Journal of Neuroscience Version of Record2 Apr 2026Published Copyright This work is licensed under a Non Exclusive No Reuse License. Collection

Authors Metrics & Citations Metrics Article Usage 378views 165downloads Citations Download citation Riko Iizuka, Ryotaro Yamaki, Tomoyo Shiramatsu, et al. Dopamine in the Nucleus Accumbens Signals Salience of Auditory Deviance. Authorea. 07 October 2025. DOI: https://doi.org/10.22541/au.175981195.52564166/v1 DOI: https://doi.org/10.22541/au.175981195.52564166/v1 If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download. For more information or tips please see 'Downloading to a citation manager' in the Help menu.