Attenuated effect of tungsten carbide nanoparticles on voltage-gated sodium current of hippocampal CA1 pyramidal neurons

Nanomaterials and relevant products are now being widely used in the world, and their safety becomes a great concern for the general public. Tungsten carbide nanoparticles (nano-WC) are widely used in metallurgy, aeronautics and astronautics, however our knowledge regarding the influence of nano-WC on neurons is still lacking. The aim of this study was to investigate the impact of nano-WC on tetrodotoxin (TTX)-sensitive voltage-activated sodium current (I_Na) of hippocampal CA1 pyramidal neurons. Results showed that acute exposure of nano-WC attenuated the peak amplitudes of I_Na in a concentration-dependent manner. The minimal effective concentration was 10^?5 g/ml. The exposure of nano-WC significantly decreased current amplitudes of the current–voltage curves of I_Na from ?50 to +50 mV, shifted the steady-state activation and inactivation curves of I_Na negatively and delayed the recovery of I_Na from inactivation state. After exposure to nano-WC, the peak amplitudes, overshoots and the V-thresholds of action potentials (APs) were markedly reduced. These results suggested that exposure of nano-WC could influence some characteristics of APs evoked from the hippocampal CA1 neurons by modifying the kinetics of voltage-gated sodium channels (VGSCs).