Measuring the impact of probabilistic transmission on neuronal output

Neuron. 1993 Jun;10(6):1101-11. doi: 10.1016/0896-6273(93)90058-y.


We have investigated the impact of stochastic transmission on the input-output relations of neurons in hippocampal slices. A synaptic input that fires a cell has a significant trial-to-trial variability in amplitude, reflecting the probabilistic release of transmitter. By measuring miniature excitatory postsynaptic currents, we estimate that synchronous release of a few vesicles can fire a CA1 cell. The firing threshold and variability can be physiologically modulated. Different cell types have distinct firing thresholds and variabilities. Long-term potentiation (LTP) decreases trial-to-trial variability. If after LTP, the stimulus is reduced to produce a threshold response, the variability returns to that observed before LTP. Thus, for a threshold input, the trial-to-trial variability is maintained with LTP. This may be important for the proper functioning of a plastic nervous system.

MeSH terms

  • Action Potentials
  • Animals
  • Evoked Potentials / drug effects
  • Hippocampus / physiology*
  • In Vitro Techniques
  • Mathematics
  • Models, Neurological*
  • Neurons / drug effects
  • Neurons / physiology*
  • Probability
  • Pyramidal Tracts / physiology*
  • Rats
  • Stochastic Processes
  • Synapses / physiology*
  • Tetrodotoxin / pharmacology


  • Tetrodotoxin