Fig. 8

Blockade of D2R did not affected the intrinsic firing behaviors in the AST-derive dopamine neurons, or mouse dopamine neuron overexpressing α-synuclein. a Left: interspike interval (ISI) distribution observed in AST-derived dopamine neurons. The 50% probability was below 0.25 s. Right: ISI distribution observed in AST-derived dopamine neurons after sulpiride applications (5 μM), the 50% probability was below 0.25 s. b Left: ISI distribution observed in mouse dopamine neurons overexpressing α-synuclein. Right: ISI distribution observed in mouse dopamine neurons overexpressing α-synuclein during sulpiride applications (5 μM). c Left: Instantaneous frequency distribution obtained from AST-derived dopamine neurons. Right: Instantaneous frequency distribution obtained from AST-derived dopamine neurons during sulpiride applications. d Left: Instantaneous frequency distribution obtained from mouse dopamine neurons overexpressing α-synuclein. Right: Instantaneous frequency distribution obtained from mouse dopamine neurons overexpressing α-synuclein during sulpiride applications. e Mean firing frequency is plotted against %SWB for the AST-derived dopamine neurons before (aqua blue) and during sulpiride applications (brown). Inset shows sulpiride did not affect %SWB in either AST-derived dopamine neurons or mouse dopamine neurons overexpressing α-synuclein. f Mean firing frequency plotted against %SWB for mouse dopamine neurons overexpressing α-synuclein before (navy-blue) and during sulpiride applications (wine). g Mean firing frequency is plotted against up-state for the AST-derived dopamine neurons before (aqua blue) and during sulpiride applications (brown). h Mean firing frequency is plotted against up-state for mouse dopamine neurons overexpressing α-synuclein before (navy-blue) and during sulpiride applications (wine). Inset shows sulpiride significantly increased up-state in both AST-derived dopamine neurons and mouse dopamine neurons overexpressing α-synuclein. i and j Sulpiride did not affect the spike half-width the spike half-amplitude in either experimental groups (AST-derived dopamine neurons or mouse dopamine neurons overexpressing α-synuclein). k, l, m, and n Sulpiride application did not produce additional change in: coefficient of variation of the interspike intervals (k, p > 0.05; one-way ANOVA followed by Tukey's test, n = 6 for AST, n = 8 for mouse), spontaneous firing rates (l, p > 0.05; one-way ANOVA followed by Tukey's test, n = 6 for AST, n = 8 for mouse), and %SWB (m, p > 0.05; one-way ANOVA followed by Tukey's test, n = 6 for AST, n = 8 for mouse), but increased up-state (n, p < 0.05; one-way ANOVA followed by Tukey's test, n = 6 for AST, n = 8 for mouse) in either experimental groups