Effects of Enriched Environment on Apoptosis and Brain-derived Neurotrophic Factor /Tyrosine Kinase Receptor B Signaling Pathway in Hippocampal Neurons of Neonatal Rats with Hypoxic-ischemic Brain Damage / 中国康复理论与实践

ABSTRACT

Objective:To investigate the effects of enriched environment on hippocampal neuronal apoptosis and brain-derived neurotrophic factor (BDNF)/tyrosine kinase receptor B (TrkB) signaling pathway in neonatal rats with hypoxic-ischemic brain damage. Methods:Forty-eight newborn Wistar rats aged seven days were randomly divided into sham operation group, model group and enriched environment group, each group was divided in to 14 days group and 28 days group, with eight in each subgroup. The model was established with the Rice method. The sham operation group and the model group did not receive any intervention, and the enriched environment group received enriched environment stimulation 24 hours after modeling. Fourteen days and 28 days after modeling, the levels of neuronal apoptosis in hippocampus were detected by TUNEL and double immunofluorescence staining; BDNF and TrkB proteins in hippocampus were detected by immunohistochemical staining. Results:Fourteen days and 28 days after modeling, the numbers of TUNEL positive cells, double immunofluorescence positive cells, BDNF and TrkB positive cells were significantly more in the model group than in the sham operation group (t > 27.214, P < 0.001), while the numbers of TUNEL positive cells, double immunofluorescence positive cells were significantly less in the enriched environment group than in the model group (t > 12.687, P < 0.001); and the number of BDNF and TrkB positive cells were significantly more in the enriched environment group than in the model group 28 days after modeling (t > 137.998, P < 0.001). Conclusion:Enriched environmental stimulation could reduce the apoptosis of hippocampal neurons, and up-regulate the expression of BDNF and TrkB proteins in the neonatal rats with hypoxic-ischemic brain damage.