Measurement and analysis of postsynaptic potentials using a novel voltage-deconvolution method.
Accurate measurement of postsynaptic potential amplitudes is a central requirement for the quantification of synaptic strength, dynamics of short-term and long-term plasticity, and vesicle-release statistics. However, the intracellular voltage is a filtered version of the underlying synaptic signal and so a method of accounting for the distortion caused by overlapping postsynaptic potentials must be used. Here a voltage-deconvolution technique is demonstrated that defilters the entire voltage trace to reveal an underlying signal of well-separated synaptic events. These isolated events can be cropped out and reconvolved to yield a set of isolated postsynaptic potentials from which voltage amplitudes may be measured directly-greatly simplifying this common task. The method also has the significant advantage of providing a higher temporal resolution of the dynamics of the underlying synaptic signal. The versatility of the method is demonstrated by a variety of experimental examples, including excitatory and inhibitory connections to neurons with passive membranes and those with activated voltage-gated currents. The deconvolved current-clamp voltage has many features in common with voltage-clamp current measurements. These similarities are analyzed using cable theory and a multicompartment cell reconstruction, as well as direct comparison to voltage-clamp experiments.
Warwick Systems Biology Centre, University of Warwick, Coventry CV4 7AL, United Kingdom. magnus.richardson@warwick.ac.uk
Magnus J E
MJ
Richardson
Gilad
G
Silberberg
D000818:Animals; D004558:Electric Stimulation / Q000379:methods*; D019706:Excitatory Postsynaptic Potentials / Q000502:physiology*; D066298:In Vitro Techniques; D008959:Models, Neurological; D009474:Neurons / Q000502:physiology / Q000528:radiation effects*; D018408:Patch-Clamp Techniques / Q000379:methods*; D051381:Rats; D013003:Somatosensory Cortex / Q000166:cytology; D013997:Time Factors