(A) Diagram of GPe synapse analysis approach of IP-controls and IP-cKOs. The GPe is stained for VGAT and gephyrin. “Colocalization” of VGAT and gephyrin marks GABAergic inhibitory synapses. Miniature inhibitory postsynaptic currents (mIPSCs) were recorded from medial GPe neurons.
(B) Representative images of inhibitory synapses in the GPe of 2-month-old IP-controls and IP-cKOs stained for VGAT (green) and gephyrin (red).
(C) Inhibitory synapse numbers are reduced in the GPe of 2-month-old IP-cKO mice compared with controls (n = 3–4 replicates/animal, 3 animals/genotype, 110 total images analyzed, nested ANOVA by genotype, F = 44.26, df = 1, p < 0.0001; graph displays mean ± SEM).
(D) Sample mIPSC traces from 2-month-old IP-control and IP-cKO medial GPe neurons.
(E) Left: the mean frequency of GPe mIPSCs is reduced in 2-month-old IP-cKOs compared with IP-controls (n = 7–8 cells per genotype, unpaired two-way t test, p = 0.0056, t = 3.309, df = 13; graph displays mean ± SEM). Right: the distribution of GPe mIPSC inter-event interval cumulative probability differs between 2-month-old IP-cKOs and IP-controls (Kolmogorov-Smirnov test, p < 0.0001).
(F) Left: there is no difference in the mean amplitude of GPe mIPSCs of 2-month-old IP-cKOs compared with IP-controls (n = 7–8 cells per genotype, unpaired two-way t test, p = 0.8535, t = 0.1883, df= 13; graph displays mean ± SEM). Right: the distribution of GPe mIPSC amplitude cumulative probability does not differ between 2-month-old IP-cKOs and IP-controls (Kolmogorov-Smirnov test, p = 0.7725).
See Figure S4.