Figure 2. Activation of PSAM⁴-GlyR in D1-MSNs produces an inward current.

(A) Representative traces of whole-cell voltage-clamp recordings (V_hold −88 mV) demonstrate no effect of uPSEM⁷⁹² (10 or 50 nM) in control neurons. In PSAM⁴-GlyR⁺ neurons, 10 or 50 nM uPSEM⁷⁹² produced an inward current. Dashed line is baseline whole-cell current for ease of visualization. (B) Plot of the magnitude of the inward current produced by 10, 50, or 100 nM uPSEM⁷⁹² in PSAM⁴-GlyR⁺ neurons. Line and error bars represent means ± SEM. (C) To measure membrane resistance (R_m), a 10 mV voltage step (−88 to −78 mV) was made in aCSF and during the uPSEM⁷⁹²-induced inward current, and the instantaneous change in current following the capacitive transient was measured (ΔI). Representative traces are shown below the voltage step command. Dashed line is 0 pA. (D) In PSAM⁴-GlyR⁺ neurons, 50 nM uPSEM⁷⁹² significantly decreased R_m (paired t-test, p<0.0001) while 10 nM showed a trend toward lower R_m (paired t-test, p=0.08). * indicates statistical significance, ns denotes not significant.