Salicylate enhances expression and function of NMDA receptors in cochlear spiral ganglion neurons

ObjectiveTo study the effect of salicylate on the expression and function of NMDA receptors in spiral ganglion neurons (SGNs).MethodsThe mRNA of NR1 subunit of NMDA receptor in modiolus tissues were detected by Real time fluorescence quantitative PCR (FQ–PCR). NMDA receptor whole–cell currents were recorded using patch clamp in acute isolated SGNs.ResultsCompared with the control group, salicylate significantly increased the mRNA level of NR1 subunit in SGNs. NMDA of concentrations ranging from 0.1 mM to 10 mM evoked no current in SGNs. NMDA (0.1mM and 0.5 mM) applied with salicylate (5 mM), however, induced inward currents (212.6±15.2pA, n=5; 607.9±44.3pA, n=5) in a dose–dependent manner, which could be inhibited by APV. Salicylate alone did not produce any current in SGNs.ConclusionSalicylate increases the expression of NMDA receptors and facilitates the currents mediated by NMDA receptors in SGNs.