Extended Data Fig. 7: PV-ChR2 stimulation enhances inhibitory synaptic transmission in PCs from mPFC slices.
From: GABAergic signaling to astrocytes in the prefrontal cortex sustains goal-directed behaviors
(a) Confocal images showing PV cells expressing ChR2 after viral transfection with AAV2.5-Ef1a-DIO-hChR2(H134R)-mcherry: NeuN (blue), ChR2 (red) and astrocytic marker S100 (green). Scale bar, 10 μm. (b) Top, Scheme of experimental approach stimulating PV-expressing ChR2 interneurons with blue light while recording PCs from layer 2/3. Bottom, Representative IPSCs traces from PCs before and after PV-ChR2 stimulation (light stim 30 s) in control and in Ip3r2-/–PV-ChR2 mice (average traces from 20 consecutive responses). Note the absence of synaptic modulation in Ip3r2-/–PV-ChR2 mice. (c) Relative changes of IPSC amplitude over time after PV-ChR2 activation (blue arrow denotes light stimulation, 30 s) for control, PV-ChR2 mice, and in absence of Ca2+ signaling in astrocytes, Ip3r2-/–PV-ChR2 mice. Inset, Pie plot representing the percentage of PCs showing changes (73%, gray) vs no changes (27%, blue) in IPSCs amplitude after PV-ChR stimulation. Note the similar values found for IPSCs potentiation after single PV cell depolarization (Extended Data Fig. 6a), and after stimulation of the PV interneuron population with ChR2, confirming the consequences of selective PV activation and astrocytic recruitment for the inhibitory synaptic plasticity at mPFC. (d) BW plot showing changes in IPSC amplitude after 10 min PV-ChR2 stimulation for control (n =15; P < 0.001), Ip3r2-/–PV-ChR2 (n =10; P < 0.001), and control + CGP 55845 (n =11; P = 0.019) and LY367385 (n =7; P = 0.042; One-way ANOVA two-sided). (e) Time course of relative IPSC changes right after PV-single depolarization (n = 16), PV-ChR2 (n = 10) and melanopsin-astrocytes (n = 10). (f) BW plot showing changes in IPSC amplitude after 30 and 60 s post stimulation. Note the faster onset of IPSC potentiation for PV-single depolarization and PV-ChR2 compared with melanopsin-activated astrocytes. * P <0.05; *** P <0.001 One-way ANOVA two-sided (see Source Data file). Data shown are mean±SEM. Box plots indicate median and whiskers indicate the 25th and 75th percentiles, respectively.
