Effects of Enriched Environment on Locomotion and Cognition in Neonatal Rats with Hypoxic-Ischemic Encephalopathy

ABSTRACT

OBJECTIVE: To investigate the effect of environmental enrichment on the cognitive and motor development in the experimental hypoxia-ischemic encephalopathy neonatal rat model. METHOD: Hypoxic-ischemic encephalopathy models were made in neonatal Sprague-Dawley rats at 3 days of age by ligating the unilateral carotid artery followed by inhalation of 8% oxygen and raised in the enriched environment (n=10), treadmill exercise (n=8) and non-stimulation (n=10) from the 3rd to 8th weeks of age. Neurobehavioral and histopathological changes were compared. RESULTS: The neurobehavioral tests of the rats with hypoxic-ischemic encephalopathy showed prolonged latencies of achievement for cliff avoidance and negative geotaxis (p<0.05). Persisting abnormality into adult life of limb placing improved in exercise and enriched environment groups and spatial learning and memory in a water maze recovered in the rats with enriched environment (p<0.05). The density of dendritic spine increased in the hippocampus with enriched environment (p<0.05). CONCLUSION: The present study supports the possibilities of the positive effects after the enriched environment in the developing brain with hypoxic injury.