highly significantp<0.0001
The TUNEL counts for the Grk1 −/− ;B6J mice were also highly significant compared to the B6J and B6N mice in the 1-month-old superior retinas (****p<0.0001) but were less significant for the 1- and 3-month-old inferior retinas (***p<0.001) and the 3-month-old superior retinas (**p<0.01).