Deviance sensitivity in the auditory cortex of freely moving rats

PLoS One. 2018 Jun 6;13(6):e0197678. doi: 10.1371/journal.pone.0197678. eCollection 2018.

Abstract

Deviance sensitivity is the specific response to a surprising stimulus, one that violates expectations set by the past stimulation stream. In audition, deviance sensitivity is often conflated with stimulus-specific adaptation (SSA), the decrease in responses to a common stimulus that only partially generalizes to other, rare stimuli. SSA is usually measured using oddball sequences, where a common (standard) tone and a rare (deviant) tone are randomly intermixed. However, the larger responses to a tone when deviant does not necessarily represent deviance sensitivity. Deviance sensitivity is commonly tested using a control sequence in which many different tones serve as the standard, eliminating the expectations set by the standard ('deviant among many standards'). When the response to a tone when deviant (against a single standard) is larger than the responses to the same tone in the control sequence, it is concluded that true deviance sensitivity occurs. In primary auditory cortex of anesthetized rats, responses to deviants and to the same tones in the control condition are comparable in size. We recorded local field potentials and multiunit activity from the auditory cortex of awake, freely moving rats, implanted with 32-channel drivable microelectrode arrays and using telemetry. We observed highly significant SSA in the awake state. Moreover, the responses to a tone when deviant were significantly larger than the responses to the same tone in the control condition. These results establish the presence of true deviance sensitivity in primary auditory cortex in awake rats.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acoustic Stimulation
  • Adaptation, Physiological*
  • Animals
  • Auditory Cortex / physiopathology*
  • Auditory Perception / physiology
  • Evoked Potentials, Auditory
  • Rats
  • Wakefulness / physiology*

Grants and funding

This work was supported by a European Research Council (ERC) advanced grant GA-340063 (project RATLAND) to IN, by F.I.R.S.T. grant no. 1075/2013 from the Israel Science Foundation to IN, and by a grant from the Gatsby Charitable Foundation. MMJ and AP were partially supported by the Edmond and Lily Safra Center for Brain Sciences (ELSC) at the Hebrew University. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.