The inhibitory effects of nano‐Ag on voltage‐gated potassium currents of hippocampal CA1 neurons

Abstract

The application of the nano‐sized materials continues to grow at a rapid rate in the fields of medicine, biotechnology, and environmental technology. Voltage‐gated potassium currents play a key role in excitable cellular viability and function, especially in the central nervous system. The aim of this study was to investigate the actions of silver nano‐particles (nano‐Ag) on voltage‐activated potassium currents in hippocampal CA1 neurons using whole cell patch‐clamp technique. The hydrodynamic mean diameter of nano‐Ag (10⁻⁵g mL⁻¹) was 223.9 nm in artificial cerebrospinal fluid (ACSF). Both types, transient potassium (I_A) and delayed rectifier potassium (I_K) current amplitudes were inhibited by the nano‐Ag (10⁻⁵g mL⁻¹). The nano‐Ag particles produced a hyperpolarizing shift in the activation‐voltage curve of I_K and inactivation‐voltage curve of I_A and also delayed the recovery of I_A from inactivation. The results suggest that nano‐Ag may have potential to alter the excitability of neurons by depressing the potassium channels. © 2010 Wiley Periodicals, Inc. Environ Toxicol, 2010.