Figure 1. Neurons in mouse primary visual cortex respond to UV drifting gratings.

(a) Two-photon fluorescence images were collected from GCaMP6-labeled neurons in primary visual cortex of mouse presented with drifting grating stimuli. (b) Normalized spectral sensitivity for S-opsin (purple), M-opsin (green), and rhodopsin (black). Shaded rectangles indicate the wavelength ranges of the UV and visible light sources. (c) Left, an example two-photon fluorescence image. Right, neuronal responses to UV drifting gratings over the same imaging field. Dots indicate neurons that exhibited significant responses but no orientation selectivity. Bars mark neurons that exhibited significant tuning for the oriented drifting gratings, with the bar orientation matching the orientation preference of each neuron. Scale bar: 20 μm. (d) Somatic calcium time courses for four example neurons labeled in (c). Light gray regions illustrate the 5-second duration of drifting grating stimulus. The average response across all 10 trials of a given stimulus condition is shown in purple trace, with the standard error across trials shaded in dark gray. Vertical scale bars: 40% ∆F/F. Horizontal scale bar: 5 s. (e) Orientation tuning curves for four neurons shown in c generated by averaging ∆F/F over the five-second window following the stimulus onset. Purple circles, mean; vertical purple line, error bar, SEM.; purple curve, fit to a double Gaussian function.