Fig. 1.
DA-promoted bursting in layer V PCs. (A) Bursting responses promoted by DA (25 μM) with bath application of AP-5 (50 μM) and bicuculline (5 μM) to block NMDA and GABAA receptors, respectively. (Top) Before applying DA, 12 superimposed single non-NMDA EPSPs (0.1 Hz) simultaneously recorded from two layer V PCs. (Middle) Burst firing in all sweeps after applying DA for 3 min. (Bottom) Bursting disappeared after washout of DA for 15 min. (B) Bursting threshold reduced by DA. In control (Left), bursting was elicited at a stimulation strength of 3.6 μA. After applying DA (Right), bursting responses were triggered by stimulation at 2.5 μA. Additionally, the amplitudes of EPSPs evoked at a stimulating strength of 2.4 μA is higher than those evoked at a stimulating strength of 3.5 μA in control. Scale bars refer to EPSPs (small vertical calibrations) and APs (large vertical calibrations).