Fig. 6

Cone inputs to melanopsin-responsive cells provide information about gradual changes in illuminance or colour. a Example peristimulus firing rate histograms for three MR neurons tested with sinusoidal oscillations of their optimal cone stimulus type (L − S modulation for chromatic units and L + S stimulus for the non-opponent unit—right) at 75% contrast and varying temporal frequency. b Population data showing, for each responding MR cell and non-MR cell (as defined in Fig. 2), the range of frequencies that drove significant modulations in the firing rate and preferred temporal frequency for optimal cone stimuli (indicated by start and endpoints of each line and symbols respectively; assessed by χ²-periodogram, see ‘Methods’ for further details). n.r. indicates no significant response at any frequency. Inset pie charts show proportions with significant response and strongest responses at 0.025 Hz. Data analysed by Fisher’s exact test, * and ** = < 0.05 and 0.01 respectively. c Cumulative distribution for MR and non-MR (same populations as in b) responses to 75% contrast stimuli applied to dominant cone opsin (quantified as percentage variance in firing rate accounted for by the 0.025-Hz stimulus). Data analysed by Kolmogorov-Smirnov test, *** = P < 0.0001. d Quantification of responses for low-frequency L- and S-opsin-driven responses across each responding MR cell (quantified as in c). e Normalised responses to low-frequency L- and S-opsin-isolating stimuli for each class MR neuron; thin traces represent individual cells, thicker lines represent population average. f Data for achromatic MR units (bottom panels of d) sorted according to preferred and non-preferred opsin based on analysis in Fig. 2