Previous studies have established that spike activity in RGCs in the rd-1/rd-1 mutant (RD1) mouse, a well studied model of human RP, is driven by rhythmic synaptic input from presynaptic retinal neurons [5], [8], [10], [12] but the extent to which this activity is synchronized is not clear [10], [11], [13]. This evidence concerns the gene PDE6B and retinitis pigmentosa 1.