Article abstract

Nature Methods 7, 399 - 405 (2010)
Published online: 18 April 2010 | Corrected online: 6 May 2010 | doi:10.1038/nmeth.1453

There is an Erratum (June 2010) associated with this Article.

High-speed in vivo calcium imaging reveals neuronal network activity with near-millisecond precision

Benjamin F Grewe1, Dominik Langer1, Hansjörg Kasper1, Björn M Kampa1 & Fritjof Helmchen1

Two-photon calcium imaging of neuronal populations enables optical recording of spiking activity in living animals, but standard laser scanners are too slow to accurately determine spike times. Here we report in vivo imaging in mouse neocortex with greatly improved temporal resolution using random-access scanning with acousto-optic deflectors. We obtained fluorescence measurements from 34–91 layer 2/3 neurons at a 180–490 Hz sampling rate. We detected single action potential–evoked calcium transients with signal-to-noise ratios of 2–5 and determined spike times with near-millisecond precision and 5–15 ms confidence intervals. An automated 'peeling' algorithm enabled reconstruction of complex spike trains from fluorescence traces up to 20–30 Hz frequency, uncovering spatiotemporal trial-to-trial variability of sensory responses in barrel cortex and visual cortex. By revealing spike sequences in neuronal populations on a fast time scale, high-speed calcium imaging will facilitate optical studies of information processing in brain microcircuits.

  1. Department of Neurophysiology, Brain Research Institute, University of Zurich, Zurich, Switzerland.

Correspondence to: Fritjof Helmchen1 e-mail:

* In the version of this article initially published, equation 1 was incorrect. The error has been corrected in the HTML and PDF versions of the article.


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