ABSTRACT
BACKGROUND:Studies have shown that pulsed electromagnetism has a good effect in promoting peripheral nerve regeneration after cerebral infarction and spinal cord injury, and improving memory function in patients with neurological disorders. OBJECTIVE: To investigate the impact of pulsed magnetic field on brain function and endogenous neural stem cell factor in the brain tissue of rats with brain injury. METHODS: Totally 320 adult male Sprague-Dawley rats were randomly divided into model group, pulsed magnetic field 0.1 mT group, pulsed magnetic field 0.3 mT group and pulsed magnetic field 0.5 mT group (n=80 per group). After brain injury models were established using lateral hydraulic strike method, rats in the latter three groups were exposed to pulsed magnetic fields 0.1, 0.3, 0.5 mT, respectively. After electromagnetic radiation 1, 3, 7, 14 days, the motor function of rats was evaluated by beam-walking test and water maze test. Rats were intraperitoneally injected 5-deoxy-uridine (BrdU) at 1 day prior to different radiation time points, and BrdU and nestin expressions in the cerebral cortex were measured by immunohistochemical method. RESULTS AND CONCLUSION: (1) The time of water maze test and the beam-walking test at 1, 3 and 7 days after irradiation was ranked as follows: pulse magnetic field 0.5 mT < pulse magnetic field 0.3 mT < pulse magnetic field 0.1 mT < model group, and there were significant differences between groups (P < 0.05). (2) The expressions of BrdU and nestin at 1, 3 and 7 days after irradiation were highest in the pulse magnetic field 0.5 mT group, successively followed by pulse magnetic field 0.3 mT group, pulse magnetic field 0.1 mT group and model group (P < 0.05). In summary, the pulse magnetic field exhibits remarkable protective effects on the brain function of rats with craniocerebral injury in an intensity-dependent manner. The possible mechanism is related to the activation of neural stem cells and the proliferation of neural stem cells in the brain tissue of rats with craniocerebral injury.