(A) mPer2Luc retinal explants cultured from B6C3 mice exhibited sustained circadian rhythms in PER2::LUC expression.
(B) mPer2Luc retinal explants cultured from C57BL/6J mice also showed robust circadian oscillation of PER2::LUC expression.
(C–H) Circadian PER2::LUC expression rhythms persisted upon continuous application of: (C) melatonin (10 nM); (D) the melatonin MT1 receptor antagonist luzindole (5 μM); (E) l-glutamate (1 mM); (F) the broad-spectrum glutamate receptor antagonist kynurenic acid (0.5 mM); (G) the voltage-gated sodium channel blocker TTX (1 μM); and (H) the gap junction block carbenoxolone (100 μM).
(I and J) Retinal explants cultured from cx36−/− mice (I) and cx36+/− mice (J) did not show differences in the damping rate of PER2::LUC rhythms.
Bars indicate the duration of treatment.