Fig. 4. D₃R signaling does not affect Na⁺ or K⁺.

(A) AP train-evoked Na⁺ influx in the AIS, imaged with SBFI, before (black) and after 1 μM quinpirole (grey). Na⁺ transients were computed as the change in SBFI fluorescence over baseline.

(B) AP train-evoked Na⁺ influx in the AIS before (black) and after 1 nM TTX (grey).

(C) Summary of pharmacological effects on AIS Na⁺. Values normalized to baseline ΔF/F₀ amplitudes. Dots are single cells. Error bars are SEM. Asterisk: p < 0.01.

(D) Persistent Na⁺ currents before (black) and after quinpirole (grey).

(E) K⁺ currents before (black) and after quinpirole (grey).

(F) K⁺ current vs. step voltage. Black: baseline. Grey: quinpirole. Data from each condition superimpose. Bars are SEM.