Turning on and off recurrent balanced cortical activity

Nature. 2003 May 15;423(6937):288-93. doi: 10.1038/nature01616.


The vast majority of synaptic connections onto neurons in the cerebral cortex arise from other cortical neurons, both excitatory and inhibitory, forming local and distant 'recurrent' networks. Although this is a basic theme of cortical organization, its study has been limited largely to theoretical investigations, which predict that local recurrent networks show a proportionality or balance between recurrent excitation and inhibition, allowing the generation of stable periods of activity. This recurrent activity might underlie such diverse operations as short-term memory, the modulation of neuronal excitability with attention, and the generation of spontaneous activity during sleep. Here we show that local cortical circuits do indeed operate through a proportional balance of excitation and inhibition generated through local recurrent connections, and that the operation of such circuits can generate self-sustaining activity that can be turned on and off by synaptic inputs. These results confirm the long-hypothesized role of recurrent activity as a basic operation of the cerebral cortex.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Action Potentials
  • Animals
  • Cerebral Cortex / cytology
  • Cerebral Cortex / physiology*
  • Electric Stimulation
  • Excitatory Postsynaptic Potentials / physiology
  • Ferrets / physiology*
  • In Vitro Techniques
  • Interneurons / physiology
  • Nerve Net / cytology
  • Nerve Net / physiology
  • Neurons / physiology*
  • Pyramidal Cells / physiology
  • Synapses / physiology