Extended Data Figure 2. Microglia deficient mice show normal baseline behaviors but exaggerated responses to neurostimulants.

a, Dot plots show the average number of microglia per mm² in cortex, striatum, cerebellum and hippocampus in control and microglia deficient mice (n=3 and 4 mice, cortex: P<0.0001, striatum: P=0.0003, cerebellum: P=0.0001, DG: P<0.0001, CA3: P<0.0001, CA1: P<0.0001, unpaired two-tailed t-test). b-e, Behavioral characteristics of microglia deficient mice. b, Anxiety-like behavior was measured by the ratio of time spent in the open arms/closed arms in the elevated plus maze (n=10 mice, P=0.65, unpaired two-tailed t-test). c, Motor coordination was measured by latency to fall from the accelerating rotarod (n=8 and12 mice, interaction: P=0.89, time: P=0.13, treatment: P=0.36; subjects: P<0.0001, Two-way repeated measures ANOVA). d, Olfactory behavior was measured by the sniff test (n=21 and 13 mice, P=0.09, unpaired two-tailed t-test). e, Social behavior was measured by using the classic three-chamber sociability task (Social preference: mouse preference for sniffing another mouse over object, Control: n=7 mice; P=0.0002, microglia deficient: n=9 mice, P<0.0001; Social Memory: mouse preference for sniffing novel mouse over familiar mouse, Control n=7 mice, P=0.0023, microglia deficient: n=7 mice, P=0.0009; paired two-tailed t-test). f, Representative images show brain-wide gene expression patterns of receptors targeted by kainic acid (kainate and AMPA receptor), picrotoxin (GABA_A receptor), and SKF81297 (D1 receptor) (Allen Institute). g, Number of stage IV-V seizures (Racine scale⁹⁰) per mouse visually recorded within one hour in response to kainic acid (18mg/kg, i.p.) are shown as a dot plot (n=9 and 10 mice, P=0.0008, unpaired two-tailed t-test). h, Dot plot showing distance traveled in response to D1 agonist in one hour in the open field (SKF81297, 3mg/kg, i.p.)(n=14 and 8 mice, P=0.025, unpaired two-tailed t-test). i, Representative cortical EEG traces during a tonic-clonic seizure event in response to D1 agonist treatment (SKF81297, 5mg/kg i.p.) in control (top) and microglia deficient (bottom) mice showing high amplitude and rhythmic discharges followed by EEG depression. DG: dentate gyrus; Data shown as mean± s.e.m.