How do synapses measure milliseconds?

Thomas G Oertner

doi:10.3389/neuro.10.007.2009

Abstract

How do synapses measure milliseconds?

Highlights

Experimental validation of a theoretical prediction by measurements has often produced a critical step forward in our understanding of brain function
Due to the slow off-rate for glutamate, NMDAR currents decay with a time constant of ∼100 ms, too slow to explain the 10–20 ms window for induction of longterm potentiation by spike timing dependent plasticity (STDP) (Clements et al, 1992; Franks and Sejnowski, 2002; Sjostrom et al, 2008)
The half duration of NMDAR activation at physiological Mg2+ concentrations has been estimated to be 43 ms (Kampa et al, 2004), significantly shorter than previous estimates, but still too long to explain the size of the STDP window (Figure 1)

Summary

Introduction

Experimental validation of a theoretical prediction by measurements has often produced a critical step forward in our understanding of brain function. 27, 11940–11948 and Kinetics of Mg2+ unblock of NMDA receptors: implications for spike-timing dependent synaptic plasticity. The time course of NMDAR activity does not fit very well the length of the potentiation window.

Results

Conclusion