ABSTRACT
Objective To explore the effect and the mechanism of modulated magnetic pulse fields on memory retention and retrieval ability of rats. Methods The influence of different pulsed magnetic fields on memory performance of rats was evaluated by using cross maze test, the morphological changes of neurons and nerve synapses in the hippocampus of rats were observed by the electronic microscopy. Results The 20 Hz modulated-pulse magnetic field impaired the memory retrieval ability and the memory retention significantly after 1 hour of exposure of the rats to it ( P 0.05). These influences on nerve tissues were also observed in rats underwent the 10Hz modulated magnetic stimulation, manifested as an initial increase in ability of memory in the first 24 hours after the stimulation, but no significant difference from the control was found. The influence of magnetic fields on memory depended on what the rats remembered. Conclusion Changes in the nerve synapses may be a main factor of mechanisms of the influence of pulse magnetic fields on memory ability of rats.