UP-DOWN cortical dynamics reflect state transitions in a bistable network

Elife. 2017 Aug 4;6:e22425. doi: 10.7554/eLife.22425.

Abstract

In the idling brain, neuronal circuits transition between periods of sustained firing (UP state) and quiescence (DOWN state), a pattern the mechanisms of which remain unclear. Here we analyzed spontaneous cortical population activity from anesthetized rats and found that UP and DOWN durations were highly variable and that population rates showed no significant decay during UP periods. We built a network rate model with excitatory (E) and inhibitory (I) populations exhibiting a novel bistable regime between a quiescent and an inhibition-stabilized state of arbitrarily low rate. Fluctuations triggered state transitions, while adaptation in E cells paradoxically caused a marginal decay of E-rate but a marked decay of I-rate in UP periods, a prediction that we validated experimentally. A spiking network implementation further predicted that DOWN-to-UP transitions must be caused by synchronous high-amplitude events. Our findings provide evidence of bistable cortical networks that exhibit non-rhythmic state transitions when the brain rests.

Keywords: bistability; computational network model; cortical circuit; neuroscience; rat; up down states.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Action Potentials / physiology*
  • Adaptation, Physiological
  • Anesthesia
  • Animals
  • Brain Mapping
  • Male
  • Models, Neurological*
  • Neurons / physiology
  • Rats, Sprague-Dawley
  • Somatosensory Cortex / physiology*
  • Urethane

Substances

  • Urethane

Grant support

The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.