Circuit reactivation dynamically regulates synaptic plasticity in neocortex

Nat Commun. 2013;4:2574. doi: 10.1038/ncomms3574.

Abstract

Circuit reactivations involve a stereotyped sequence of neuronal firing and have been behaviourally linked to memory consolidation. Here we use multiphoton imaging and patch-clamp recording, and observe sparse and stereotyped circuit reactivations that correspond to UP states within active neurons. To evaluate the effect of the circuit on synaptic plasticity, we trigger a single spike-timing-dependent plasticity (STDP) pairing once per circuit reactivation. The pairings reliably fall within a particular epoch of the circuit sequence and result in long-term potentiation. During reactivation, the amplitude of plasticity significantly correlates with the preceding 20-25 ms of membrane depolarization rather than the depolarization at the time of pairing. This circuit-dependent plasticity provides a natural constraint on synaptic potentiation, regulating the inherent instability of STDP in an assembly phase-sequence model. Subthreshold voltage during endogenous circuit reactivations provides a critical informative context for plasticity and facilitates the stable consolidation of a spatiotemporal sequence.

Publication types

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

MeSH terms

  • Action Potentials / physiology
  • Animals
  • Female
  • Long-Term Potentiation / physiology*
  • Male
  • Memory / physiology
  • Mice, Inbred C57BL
  • Neocortex / cytology
  • Neocortex / physiology*
  • Neurons / cytology
  • Neurons / physiology*
  • Patch-Clamp Techniques
  • Synapses / physiology*
  • Thalamus / cytology
  • Thalamus / physiology*
  • Tissue Culture Techniques