Objective: To establish a cell model predominantly expressing N-methyl-D-aspartate (NMDA) receptors comprising NR1a/NR2A
subunits and to study the biological and pharmacological characteristics of NMDA receptors. Methods: The cDNAs of NR1a and NR2A were co-
transfected into human embryonic kidney (HEK) 293 cells with liposome. The
electrophysiological experiment was performed on the transfected cells after 48-72 hour culture. L-Glutamate-evoked currents were recorded using whole cell recording technique. Results: L-Glutamate could evoke inward currents in 38 percent of cells. The currents were depressed completely by D-AP5(50 μmol/L), a selective blocker of NMDA receptors. L-Glutamate activated channels of NR1a/NR2A receptors with an EC 50 value of (8.5±0.5) μmol/L(n=5), and the currents desensitized quickly in the presence of L-glutamate with a decay time constant (τ) of (53±9) ms(n=20). The currents displayed a rectified property at the post membrane potential. Conclusion: The functional express of NMDA receptors comprising NR1a/NR2A subunits is confirmed by the electrophysiological experiment and the cell model should be valuable for further study on the biological and pharmacological properties of the expressed NMDA receptors.