Supplementary Figure 4: Simultaneous silencing and imaging activity.

a, Co-expression of ArchT (red fluorophore) and GCaMP6f (green fluorophore) in the somata and apical dendrites of L5 pyramidal neurons. Similar results were found in all mice tested (n=3). b, Intensity profile of dispersive light. Similar results were found in all mice tested (n=3). c, Tuft Ca²⁺ signal amplitudes from multiple branches of the same neuron. Classification of events as global Ca²⁺ spikes was based on the presence of a threshold crossing Ca²⁺ event (> 30%∆F/F, dotted line) in all the recorded branches. d, Global events showed higher cross-correlation values. e, Effect of light activated selective tuft silencing on the probability of Ca²⁺ events recorded in the output compartment of L5 neurons (n=200 cells; two-sided, paired Student’s t-test)(gray lines are individual cells, open circles are mean±sem). f, Relative probability of output Ca²⁺ signals as a function of Ca²⁺ event amplitude, control (black) and light manipulation (red) trials. g, Fractional reduction in Ca²⁺ event probability vs. amplitude of Ca²⁺ events (10% more reduction in event probability for every 200% increase in event amplitude). h, Whole-cell recordings from L5 neurons under anesthetized conditions. F-I curves from all neurons showing small rightward shift from light activation (symbols are mean±sem, n=6 cells). i, Summary data showing resulting change in input – output relationship from the effects of light induced shift in H (two-sided, paired Student’s t-test). j, Expected fractional change in event probability for a simulated subtractive light effect using control data in f