Rhythmic auditory cortex activity at multiple timescales shapes stimulus-response gain and background firing

TY - JOUR

T1 - Rhythmic auditory cortex activity at multiple timescales shapes stimulus-response gain and background firing

AU - Kayser, Christoph

AU - Wilson, Caroline

AU - Safaai, Houman

AU - Sakata, Shuzo

AU - Panzeri, Stefano

N1 - Copyright © 2015 Kayser et al.

PY - 2015/5/20

Y1 - 2015/5/20

N2 - The phase of low-frequency network activity in the auditory cortex captures changes in neural excitability, entrains to the temporal structure of natural sounds, and correlates with the perceptual performance in acoustic tasks. Although these observations suggest a causal link between network rhythms and perception, it remains unknown how precisely they affect the processes by which neural populations encode sounds. We addressed this question by analyzing neural responses in the auditory cortex of anesthetized rats using stimulus-response models. These models included a parametric dependence on the phase of local field potential rhythms in both stimulus-unrelated background activity and the stimulus-response transfer function. We found that phase-dependent models better reproduced the observed responses than static models, during both stimulation with a series of natural sounds and epochs of silence. This was attributable to two factors: (1) phase-dependent variations in background firing (most prominent for delta; 1-4 Hz); and (2) modulations of response gain that rhythmically amplify and attenuate the responses at specific phases of the rhythm (prominent for frequencies between 2 and 12 Hz). These results provide a quantitative characterization of how slow auditory cortical rhythms shape sound encoding and suggest a differential contribution of network activity at different timescales. In addition, they highlight a putative mechanism that may implement the selective amplification of appropriately timed sound tokens relative to the phase of rhythmic auditory cortex activity.

AB - The phase of low-frequency network activity in the auditory cortex captures changes in neural excitability, entrains to the temporal structure of natural sounds, and correlates with the perceptual performance in acoustic tasks. Although these observations suggest a causal link between network rhythms and perception, it remains unknown how precisely they affect the processes by which neural populations encode sounds. We addressed this question by analyzing neural responses in the auditory cortex of anesthetized rats using stimulus-response models. These models included a parametric dependence on the phase of local field potential rhythms in both stimulus-unrelated background activity and the stimulus-response transfer function. We found that phase-dependent models better reproduced the observed responses than static models, during both stimulation with a series of natural sounds and epochs of silence. This was attributable to two factors: (1) phase-dependent variations in background firing (most prominent for delta; 1-4 Hz); and (2) modulations of response gain that rhythmically amplify and attenuate the responses at specific phases of the rhythm (prominent for frequencies between 2 and 12 Hz). These results provide a quantitative characterization of how slow auditory cortical rhythms shape sound encoding and suggest a differential contribution of network activity at different timescales. In addition, they highlight a putative mechanism that may implement the selective amplification of appropriately timed sound tokens relative to the phase of rhythmic auditory cortex activity.

KW - Animals

KW - Auditory Cortex/physiology

KW - Auditory Perception

KW - Delta Rhythm

KW - Male

KW - Models, Neurological

KW - Rats

KW - Rats, Sprague-Dawley

U2 - 10.1523/JNEUROSCI.0268-15.2015

DO - 10.1523/JNEUROSCI.0268-15.2015

M3 - SCORING: Journal article

C2 - 25995464

VL - 35

SP - 7750

EP - 7762

JO - J NEUROSCI

JF - J NEUROSCI

SN - 0270-6474

IS - 20

ER -