To measure possible influences of the mastication and sedentary lifestyle, we imposed masticatory patterns with three different experimental diet regimes starting at 21st postnatal day during 6 (6M) or 18 (18M) months: continuous pellet hard diet, equal periods of hard followed by soft diet or equal periods of hard followed by soft followed by hard diet. To mimic the sedentary and active lifestyles, the animals were raised, respectively in standard (AP) or enriched cages (AE). To measure the effects of diet, environment and age on the exploratory activity, we performed the open field test. Young mice (AP) with altered masticatory activity demonstrated more preference for peripheric zone, but in aging and AE animals these differences were minimized. In the aging specimens maintained in AE, these differences were reappeared. About influences on learning and spatial memory, we apply the Morris water maze and the reduced masticatory activity, regardless of the environment, decreased the average rate of spatial learning and rehabilitation recovered the losses associated in young animals and the association with AE improved the learning rate in old mice. No significant correlations were observed between swimming speed and learning rate. We conclude that the change in masticatory activity influences the pattern of exploration by zones in the open field and environmental stimulation enhances the effects of aging, emphasizing the preference for peripheric zone and reduced masticatory activity impairs spatial memory during the test of the Morris water maze and rehabilitation is able to recover spatial ability. Here, the combination with AE is required in aging.
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