Figure 3: Optical stimulation of CaMKIIa-expressing neurons in the posterior thalamic nuclei induces light aversion in both dim and bright light.

(A) Posterior thalamic nuclei of C57BL/6J mice injected with AAV encoding either ChR2 or eYFP (at 55 lux: eYFP n = 8, ChR2 n = 11; at 27,000 lux: eYFP n = 12, ChR2 n = 18) were stimulated by blue laser (473 nm, 20 Hz, 5 ms pulse width, 10 mW/mm² ). Left panel shows the time mice spent in the light zone per 5 min interval over 30 min at 55 or 27,000 lux. Comparisons were made between eYFP and ChR2 groups at each time point. Right panel shows the average time per 5 min interval for individual mice. (B) The mice from panel A were also analyzed for resting behavior in the light (left panel) and dark (right panel) zones during the light/dark assay. (C) The mice from panel A were subsequently tested in the open field assay. Average percentage of the time spent in the center of the open field chamber per 5 min interval over 30 min (Laser: 473 nm, 20 Hz, 5 ms pulse width, 10 mW/mm²). (eYFP n = 8, ChR2 n = 9). For all panels, mean±SEM is shown, *p<0.05, **p<0.01, ***p<0.001, ****p<0.0001. This figure is modified from Sowers et al. 2020¹⁹.