Abstract:
Objective To invesitgate the effect of 900 MHz radio frequency magnetic field emitted by mobile phone on sodium channels of mouse cortical neurons.
Methods Brain tissues of Kunming mice at age of 7-10 days were sliced, digested, and incubated for preparation of cortical neurons using combined enzymatic and mechanical separation. For each group, 10 cells were recorded. Three exposure groups were treated with 900 MHz and 398.1 mW radio frequency magnetic field for 5, 10, or 15 min, respectively. The characteristics of transient sodium current (INa) were recorded using whole-cell patch-clamp technique to explore the impacts on the action potentials of neurons.
Results The half-activation voltage of sodium channel was hyperpolarized and the current peak was increased under 900 MHz, and the magnetic field shifted the steady-state inactivation and the activation curve in a hyperpolarized direction. The half-activation voltage changed from (-34.983& #177;0.34)mV to (-43.137& #177;0.56)mV after the exposure (P<0.05), and the slope factor changed from (2.334& #177;0.15)mV to (2.339& #177;0.36)mV (P>0.05). The half-inactivation voltage changed from (-55.809& #177;0.189)mV to (-63.64& #177;0.627)mV (P<0.05), and the slope factor changed from (4.40& #177;0.147)mV to (5.737& #177;0.54)mV (P>0.05).
Conclusion Exposure to 900 MHz magnetic field may change the transmembrane ionic currentvoltage (I-V) characteristics and the activation & inactivation characteristics of mice cortical neurons' Na channel. It also antedates action potentials and accelerates rising phase, improving excitability of neuron cells and conduction of action potential, and finally affects the physiological functions of the neurons.
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