A comparison of neuronal population dynamics measured with calcium imaging and electrophysiology
Fig 4
Forward modeling of the spike-to-fluorescence transformation largely explains difference in selectivity patterns.
A. spike-to-fluorescence model. Top: schematic plot of the spike-to-fluorescence (S2F) forward model that generates a synthetic fluorescence trace (ΔF/FSynth) from an input spike train. Middle: example fit and data of two cells. Experimental, measured ΔF/F (blue) is overlaid with the simulated ΔF/FSynth (orange) from the S2F model. The input to the model, the simultaneously recorded spikes (black), is shown below the traces. B. Distributions of the inferred model parameters for different indicators (yellow: 6s-AAV; green: 6s-TG; Purple: 6f-TG; gray: 6f-AAV. C. An example ramp-up neuron (top, ephys; bottom, 6s-AAV synthetic of that neuron); selectivity remains detectable in synthetic imaging data. D. An example ramp-down neuron (top, ephys; bottom, 6s-AAV synthetic of that neuron); selectivity becomes undetectable in synthetic imaging. E. S2F model predicts that selectivity of ramp-down neurons but not ramp-up neurons, would be often obscured in imaging datasets. Bar plot shows fraction of cells that remain detectably selective in synthetic imaging (6s-AAV synthetic, left; 6s-TG synthetic, middle; 6f-TG synthetic, right) plotted separately for ramp-down and ramp-up cells.