Prenatal inflammation induced alterations in spatial learning and memory abilities in adult offspring: Mitigated by physical exercise and environmental enrichment

Prenatal inflammation results in chronic cognitive deficits, including learning and memory impairments in offspring. This study investigated the effects of treadmill exercise followed by environmental enrichment in mitigating the learning and memory impairments in young adult rats that were prenatally exposed to lipopolysaccharide induced inflammation. Pregnant Wistar dams were injected intraperitoneally either saline (control group; 0.5ml; n=6) or LPS group (n=18) (0.5mg/Kg) on alternate days from embryonic day 14 till delivery. After delivery, pups were divided into following groups: (1) Control, (2) LPS, (3) LPS-exercise, (4) LPS-environmental enrichment and (5) LPS-exercise-environmental enrichment. Group 3, 4 and 5 were subjected either to the treadmill exercise or environmental enrichment or both respectively, on postnatal days 15 to 60 followed by an assessment of spatial abilities by Morris water maze test. The young adult rats exposed to prenatal inflammation and subjected to treadmill exercise followed by environmental enrichment displayed significant shorter latency to reach the target quadrant. Also, they spent longer duration in the target quadrant in probe trial compared to the age- matched groups subjected either to exercise or environmental enrichment and LPS group. The exercise and enriched environment during the adolescent period could be an alternative strategy to mitigate cognitive deficits in an individual who were exposed to prenatal inflammation.