Analysis of mEPSP driven spontaneous spiking of neurons in culture

Dezhe Z. Jin and H. Sebastian Seung

Howard Hughes Medical Institute
Massachusetts Institute of Technology

Cultured neurons often spontaneously fire action potentials in absence of external stimuli. Recent experiments in cultured rat hippocampal neurons have shown that blocking synaptic transmission blocks the spontaneous firing of the neurons[1]. We propose that the neuron's spontaneous spiking is driven by miniature EPSPs (mEPSPs). Our analysis is constrained by known physiological properties of synaptic transmission in rat hippocampal neurons. It is shown that the rate of the spontaneous firing is very sensitive to the frequency and average peak amplitude of the mEPSPs. Moreover, the time interval between spontaneous activation of the neuron satisfies a Poisson distribution when the mEPSP rate is small. Experiments are proposed for quantitatively testing our theory.

[1] Bacci et. al. Eur J Neurosci, 11(2):389-97, Feb 1999.