Effect of deletion of Aldh1a1 and Gpx1 on performance in three-arm Y-maze test. 4A, the absolute number of novel arm entry; 4B, the absolute number of alteration; 4C, the absolute number of total arm entry; 4D, the relative number of novel arm entry expressed as the ratio of the absolute number of novel arm entry to the absolute number of total arm entry; 4E, the relative number of alteration expressed as the ratio of the absolute number of alteration to the absolute number of total arm entry.