Fig. 1.

Light-induced currents from photoreceptors expressing GCaMP6f.

(A) Whole-cell recordings of light-induced current responses to brief (1 ms) flashes (arrow), containing ∼100 effectively absorbed photons in a wild-type photoreceptor and a photoreceptor from ninaE-GCamP6f fly (each an average of 3 responses, voltage-clamped at −70 mV). (B) Averaged quantum bumps (after aligning rising phases) from wild-type (n = 10 cells, ∼40-60 bumps per cell) and GCaMP6f expressing photoreceptors (n = 6 cells). (C) Peak amplitudes to test flashes in wild-type (n = 16) and GCaMP6f expressing photoreceptors (n = 9) were indistinguishable (P = 0.846, 2-tailed t-test). (D & E) bump amplitudes and half-widths in wild-type (n = 10) and GCaMP6f expressing photoreceptors (n = 6) also showed no significant differences (P = 0.78 and 0.32 respectively).