The long-term effects of physical exercise on recurrent neonatal seizure-induced cognitive deficit and ZnT3 expression in rat hippocampus / 中华物理医学与康复杂志

ABSTRACT

Institute of Pediatric,Suzhou University Affiliated Children's Hospital,Suzhou 215003,China Objective To explore the long-term effects of physical exercise on neonatal seizure-induced learning,memory deficit and the expression of zinc transporter-3(ZnT3)in rat hippocampus.Methods Sprague Dawlev rats aged 6 days were randomly divided into a recurrent-seizure group(RS)and a control group. At postnatal dav 6(P6),the recurrent seizures were induced by inhalation of the volatile agent flurothyl once a day for consecu tive 6 davs.The rats in the control group were placed in the container for an equal period of time as those in the RS group without exposure to flurothyl. Y-maze test was performed to evaluate learning and memory capacity at postnatal day 29 to 35 and 61 to 67,respectively.During the period of postnatal day 51 to 56,all the animals in the RS andcontrol groups were subject to a 30-minute daily aerobic exercise program for consecutive 6 days.All the animals weresacrificed at postnatal day 78,and the in situ hybridization method was used to detect the expression of ZnT3 mRNA in hippocampus. Results ①The number of trials needed for getting correct response to the electric stimulation in the first Y-maze test was(60±14.1)and(37.5±17.2)for the RS and control groups,respectively(P＜0.05),while that in the second Y-maze test carried out 24 hours later was(27.5±14.1)and(21±11.01)for the RS and the control groups,respectively(P＞0.05).②Memory test revealed no significant difference between the RS and thecontrol groups(P＞0.05).③In situ hybridization detection showed that the expression of ZnT3 mRNA in hippocam pus was not significantly different between the two groups.However,there showed a significant difference between the dentate gyrus and CA3 in the RS group with regard to the expression of ZnT3 mRNA(P＜0.05). Conclusions Physical exercise improves the learning capacity of neonatal seizure-induced cognitive deficit and might have effects on the regulation of zinc transporter gene expressions in hippocampus.