Figure 2.

Differences in the membrane properties of D₁ and D₂ MSNs. a, b, Rheobase current is significantly higher in D₁ MSNs (D₁ MSNs: median, 270 pA, n = 35; D₂ MSNs: median, 130 pA, n = 31; p < 0.001). c, Resting membrane potential is significantly more depolarized in D₂ MSNs (D₁ MSNs: median, −87.2 mV, n = 35; D₂ MSNs: median, −85.4 mV, n = 31; p < 0.05). d, Spike threshold is not significantly different. e, Input resistance measured with a −150 pA hyperpolarizing step is significantly smaller in D₁ MSNs (D₁ MSNs: median, 53.1 MΩ, n = 35; D₂ MSNs: median, 93.1 MΩ, n = 31; p < 0.05). e, f, Membrane time constant and resistance measured with a 5 mV pulse in voltage clamp from −80 mV are significantly different (R_m: D₁ MSNs: median, 124.40 MΩ, n = 35; D₂ MSNs: median, 154.83 MΩ, n = 31; p < 0.05; τ: D₁ MSNs: median, 2.9 ms, n = 28; D₂ MSNs: median, 2.3 ms, n = 30; p < 0.05). h, i, Membrane responses to intrasomatic current injection reveal a subthreshold divergence. A linear fit across resting membrane potential reveals a difference in input resistance. j, Voltage responses of D₁ and D₂ MSNs to intrasomatic current steps demonstrate increased excitability in the D₂ MSN population, as displayed in an F–I plot. *Statistical significance.