ABSTRACT
Objective To investigate the effects of various concentrations of lidocaine on the N-methyl-D-aspartate ( NMDA)-mediated calcium currents in cultured rat hippocampal neurons. Methods Hippocampal neurons were obtained from newborn Wistar rats (0-24 h after birth) . The hippocampal neurons cultured for 12-14 days were divided into control group and 5 lidocaine groups in which lidocaine was added to the extracellular solution achieving the final concentrations of 10-3 , 10-4 , 10-3 , 10-2 and 10-1 . The neuronal cells were voltage clamped at - 80 mv. The currents evoked by NMDA 100 ?mol?L-1 were recorded. The NMDA-mediated Ca currents were isolated by blocking Na-currents with TTX, K-currents with CsCL and TEACL and non-NMDA receptor (to a large degree AMPA receptor) with CNQX. Current density was calculated (pA / pF) .Results Lidocaine significantly reduced the density of NMDA-mediated calcium currents at concentrations of 10-3- 10-1 ?mol?L-1 compared with that in the control group (P