Figure 6. Inhibition and gene silencing of MAOB abolish tonic inhibition while glia-specific rescue of MAOB restores tonic inhibition in striatum.

A, effect of selegiline on MAOB activity in wild littermates and MAOB KO mice was measured from mitochondria-rich fraction which was prepared from mouse cerebral homogenate. B and C, enzyme activity assay results from cerebrum in wild littermates and MAOB KO mice. D and E, the tonic GABA_A receptor-mediated currents of medium spiny neuron (MSN) measured in control striatum slices and in slices from naïve mice treated for 1 h with selegiline (100 nm). BIC: 20 μm bicuculline. F, magnitude of bicuculline sensitive tonic current recorded MSN cells treated as indicated. G, sIPSC amplitude and frequency in MSN cells treated as indicated. H and I, the tonic GABA_A receptor-mediated currents of MSN cells measured in striatum slices from hGFAP-CreERT2 mice treated with tamoxifen and MAOB-shRNA virus injected (I) or control mice (treated with sunflower oil, H). J, magnitude of bicuculline sensitive tonic current recorded MSN cells treated as indicated. K, sIPSC amplitude and frequency in MSN cells as indicated. L and M, the tonic GABA_A receptor-mediated currents of MSN measured in striatum slices from wild littermates and MAOB KO mice. N, magnitude of bicuculline sensitive tonic current recorded MSN cells treated as indicated. O, sIPSC amplitude and frequency in MSN cells as indicated. P and Q, the tonic GABA_A receptor-mediated currents of MSN measured in striatum slices from wild littermates and MAOB KO mice at 33ºC. R, magnitude of bicuculline sensitive tonic current recorded in MSN cells treated as indicated. S, sIPSC amplitude and frequency in MSN cells as indicated. *P < 0.05; **P < 0.01.