Figure 3

Electrophysiological light responses, normalized sensitivity, and recovery of the cone-mass receptor potential in forskolin-treated WT larvae at 5 dpf.A, Representative electroretinogram (ERG) traces of isolated cone-mass receptor potentials in larvae incubated in vehicle (DMSO, dimethyl sulfoxide) or forskolin for 25 min, followed by a 5-min coincubation with 2-amino-4-phosphonobutyric acid (APB). Reponses were recorded under dark-adapted conditions to 20-ms flashes of light of increasing intensities from 0.1 cd/m² to 5000 cd/m². The fast initial positive deflection is attributed to a photovoltaic effect with the recording microelectrode. Mean-normalized peak response amplitudes were fit using the Naka–Rushton function. B, Representative ERG waveforms of treated larvae subjected to successive stimuli using a dual flash paradigm of a 20-ms flash of saturating white light (1000 cd/m²) with an interstimulus interval (ISI) of 3 s. Vertical black dotted lines indicate time of stimulus. Cone-mass receptor potential recovery was plotted as the ratio of the maximum isolated cone mass receptor potential response of the second stimulus to that of the initial stimulus for ISIs ranging from 0.75 s to 5 s. A linear mixed model analysis of covariance found a significant effect of forskolin compared to vehicle [F_{(1, 350)} = 115.6; p < 0.0001]. Error bars represent SEM.