Objective    To investigate the modulatory effect of orexin A on glutamate receptor-mediated current in the freshly isolated pyramidal neurons from the rat prefrontal cortex (PFC).     Methods    Deep layer (Ⅴ-Ⅵ) prefrontal cortical pyramidal neurons from postnatal 10 to 14 day-old Wistar rats were acutely dissociated by a combination of mechanical and enzymatic method. Subsequently

the effect of orexin A on the current induced by glutamate was studied by the technique of whole cell patch clamp.      Results    Both orexin A and glutamate dose-dependently evoked the inward transmembrane current. The current was evoked by 1 mmol/L glutamate as a control group(100%). After treatment with 1 mmol/L orexin A for 4-10 s

1 mmol/L glutamate induced-current was increased by (46.59±15.19)% (n=8

P0.01).     Conclusion    Glutamate receptor-mediated current is markedly potentiated by orexin A in the freshly isolated pyramidal neurons

which suggests that a synergistic action between orexin and glutamate systems exists in PFC.