Redistribution of synaptic efficacy between neocortical pyramidal neurons

Nature. 1996 Aug 29;382(6594):807-10. doi: 10.1038/382807a0.


Experience-dependent potentiation and depression of synaptic strength has been proposed to subserve learning and memory by changing the gain of signals conveyed between neurons. Here we examine synaptic plasticity between individual neocortical layer-5 pyramidal neurons. We show that an increase in the synaptic response, induced by pairing action-potential activity in pre- and postsynaptic neurons, was only observed when synaptic input occurred at low frequencies. This frequency-dependent increase in synaptic responses arises because of a redistribution of the available synaptic efficacy and not because of an increase in the efficacy. Redistribution of synaptic efficacy could represent a mechanism to change the content, rather than the gain, of signals conveyed between neurons.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Action Potentials
  • Animals
  • Cerebral Cortex / cytology
  • Cerebral Cortex / physiology*
  • Evoked Potentials
  • In Vitro Techniques
  • Neuronal Plasticity / physiology*
  • Patch-Clamp Techniques
  • Pyramidal Cells / physiology*
  • Rats
  • Rats, Wistar
  • Synapses / physiology*