A comparison of neuronal population dynamics measured with calcium imaging and electrophysiology
Fig 7
Temporal dispersion of population dynamics differs between imaging and ephys.
A. Heatmap of normalized trial-averaged firing rates for right trials (left) and left trials (right) for ephys data. Firing rates were normalized to maximum of activity across both conditions. Neurons were first divided into two groups by their preferred trial type then sorted by latency of peak activity. B. Same plots as A but for 6s-AAV (left), 6s-TG (middle) and 6f-TG (right). Below the 6f-TG are neurons from ephys depth matched to 6f-TG. C. Fraction of neurons with a peak at given time point over time. Distribution in time plotted simultaneously for both trial types (red: right trials, blue: left trials, black horizontal line: uniform distribution). Datasets shown left to right (from left: ephys, 6s-AAV, 6s-TG, and 6f-TG respectively). D-E. The same plots as B-C for synthetic imaging (6s-AAV synthetic, left; 6s-TG synthetic, middle; 6f-TG synthetic, right). F. Example cells with peaks at a similar time in ephys (left; mean activity, thick black line; sem, shaded area; peak, magenta circle; baseline, orange thin line) along with the corresponding synthetic data (right). Neurons are sorted according to their peak times in synthetic imaging (early to late, from top to bottom). G. Sensitivity analysis of peakiness by synthetic, artificial data (Materials and Methods). Bars show normalized peakiness for the different model variants: (1) identical S2F parameters and identical spike times; (2) identical S2F parameters, jittered spike times (3) identical S2F parameters, variable firing rate (4) identical S2F parameters except for the decay time constant of the calcium indicator that was randomly sampled from its distribution; (5) identical S2F parameters, except for the nonlinearity of the calcium indicator that was randomly sampled from its distribution; (6) both decay time constant and nonlinearity of calcium indicator randomly sampled; (7) variable decay time constant, non-linearity and firing rates. H. Same plots as B-C for inferred firing rates from imaging, i.e., synthetic ephys.