Silent synapses during development of thalamocortical inputs

Neuron. 1997 Feb;18(2):269-80. doi: 10.1016/s0896-6273(00)80267-6.


During development, activity-dependent mechanisms are thought to contribute to the refinement of topographical projections from the thalamus to the cortex. Because activity-dependent increases in synaptic strength may contribute to the stabilization of synaptic connections, we have explored the mechanisms of long-term potentiation (LTP) at thalamocortical synapses in rat somatosensory (barrel) cortex. During early postnatal development (postnatal days 2-5), we find that a significant proportion of thalamocortical synapses are functionally silent and that these are converted to functional synapses during LTP. Silent synapses disappear by postnatal day 8-9, the exact time at which the susceptibility of these synapses to LTP is lost. These findings suggest that the activity-dependent conversion of silent to functional synapses due to correlated pre- and postsynaptic activity may contribute to the early development and refinement of thalamocortical inputs to cortex.

Publication types

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

MeSH terms

  • Action Potentials
  • Age Factors
  • Animals
  • Animals, Newborn
  • Long-Term Potentiation*
  • Membrane Potentials
  • Patch-Clamp Techniques
  • Rats
  • Somatosensory Cortex / physiology*
  • Synapses / physiology*
  • Synaptic Transmission
  • Thalamus / physiology*