Experimental design. Half of the animals were submitted to the maternal deprivation (MD) protocol from PND-1 to PND-10 (groups ii, iv, and vi). Animals from groups iii to vi were familiarized to the physical exercise apparatus from PND 100 to PND 107. All animals, except the naïve, were habituated to the object recognition (OR) memory task apparatus (PND 108-111) and trained in the OR task (PND112), when they were exposed to two different new (N) objects for free exploration. Animals of groups v and vi were submitted to an aerobic exercise shot immediately after OR training. After the aerobic exercise shot, 5 animals from each group, plus 4 naïve animals, were euthanized for biochemical analysis (HPLC). The other animals were submitted to OR tests 24 h and 7, 14, and 21 days after the OR training (PNDs 113, 120, 134, and 155), when the animals were exposed to a familiar (F) and to a new object (N) for free exploration. On each testing day, always after the OR test session, the Elevated Plus Maze (EPM) test was performed as a control behavioral test to verify anxiety.