(A) The reduction of the outward current to 20 mM TEA was assayed with the protocol in figure 7. (B) Comparison of the differences in pharmacology for the total non-inactivating outward current, between early (P0) and late (P7–P15) SN DA neurons. Experimental protocol as explained in figure legends 5 & 6. Control conductance (Left white bar, G(Control, P0) nS, n = 10). At P0 the currents are insensitive to 20 mM TEA (Left Black bar, G(TEA, P0) nS, n = 4), 1 m CbTx (Left hatch bar, G(CbTx, P0) nS, n = 3) and 1 m IbTx (left criss-cross bar, G(IbTx, P0) nS, n = 2). Average control conductance pooled from P7 to P15 (Right white bar, G(Control, P7–P15) nS, n = 23). Effect of 20 mM TEA on the conductance from P7–P15 (Right black bar (G(TEA, P7–P15) nS, n = 10). Effects of 1 m CbTx (Right hatch bar G(CbTx, P7–P15) nS, n = 3) and 1 M IbTx (Right criss-cross bar, G(IbTx) nS, n = 2) on the conductance, data pooled from P7 to P15.