RT Journal Article
SR Electronic
T1 Relationship between spiking activity and simultaneously recorded fluorescence signals in transgenic mice expressing GCaMP6
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 788802
DO 10.1101/788802
A1 Lawrence Huang
A1 Ulf Knoblich
A1 Peter Ledochowitsch
A1 Jérôme Lecoq
A1 R. Clay Reid
A1 Saskia E. J. de Vries
A1 Michael A. Buice
A1 Gabe J. Murphy
A1 Jack Waters
A1 Christof Koch
A1 Hongkui Zeng
A1 Lu Li
YR 2019
UL http://biorxiv.org/content/early/2019/10/01/788802.abstract
AB Two-photon calcium imaging is often used with genetically encoded calcium indicators (GECIs) to investigate neural dynamics, but the relationship between fluorescence and action potentials (spikes) remains unclear. Pioneering work linked electrophysiology and calcium imaging in vivo with viral GECI expression, albeit in a small number of cells. Here we characterized the spike-fluorescence transfer function in vivo of 91 layer 2/3 pyramidal neurons in primary visual cortex in four transgenic mouse lines expressing GCaMP6s or GCaMP6f. We found that GCaMP6s cells have spike-triggered fluorescence responses of larger amplitude, lower variability and greater single-spike detectability than GCaMP6f cells. Single spike detection rates differed substantially across neurons in each line. They declined from ∼40-90% at 5% false positive rate under high-resolution imaging to ∼10-15% when imaging hundreds of neurons across a larger field of view. Our dataset thus provides quantitative insights to support more refined inference of neuronal activity from calcium imaging data.