A simple model of cortical dynamics explains variability and state dependence of sensory responses in urethane-anesthetized auditory cortex

J Neurosci. 2009 Aug 26;29(34):10600-12. doi: 10.1523/JNEUROSCI.2053-09.2009.


The responses of neocortical cells to sensory stimuli are variable and state dependent. It has been hypothesized that intrinsic cortical dynamics play an important role in trial-to-trial variability; the precise nature of this dependence, however, is poorly understood. We show here that in auditory cortex of urethane-anesthetized rats, population responses to click stimuli can be quantitatively predicted on a trial-by-trial basis by a simple dynamical system model estimated from spontaneous activity immediately preceding stimulus presentation. Changes in cortical state correspond consistently to changes in model dynamics, reflecting a nonlinear, self-exciting system in synchronized states and an approximately linear system in desynchronized states. We propose that the complex and state-dependent pattern of trial-to-trial variability can be explained by a simple principle: sensory responses are shaped by the same intrinsic dynamics that govern ongoing spontaneous activity.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acoustic Stimulation / methods
  • Anesthetics, Intravenous / pharmacology*
  • Animals
  • Auditory Cortex* / cytology
  • Auditory Cortex* / drug effects
  • Auditory Cortex* / physiology
  • Electric Stimulation / methods
  • Evoked Potentials, Auditory / physiology*
  • Models, Neurological*
  • Neural Pathways / physiology
  • Neurons / drug effects
  • Neurons / physiology
  • Nonlinear Dynamics*
  • Pedunculopontine Tegmental Nucleus / physiology
  • Rats
  • Rats, Sprague-Dawley
  • Urethane / pharmacology*


  • Anesthetics, Intravenous
  • Urethane