Fig. 1

VMAT2 is enriched in astrocytes located in the frontal cortex. a Representative image of the RT-PCR analysis and quantification of the relative expression of OCT3, VMAT2, MAOB and TH mRNA in FACS-sorted astrocytes in comparison with β-actin. The error bars indicate the SEM. b Representative confocal images show VMAT2 immunolabelling (red) in mouse prefrontal cortex (PFC). Astrocytes are stained with glutamine synthase (GS, green). The VMAT2 signal is highlighted by white arrows in astrocytes and grey arrows in neuronal fibres. Scale bars: 30 μm. High magnifications represent confocal images showing VMAT2 immunolabelling (red) in the PFC of mouse and rat (P30-40). Scale bars: 5 μm. c Confocal sections showing VMAT2 (red) in the ST and VTA of rats; the astrocytes are stained with GS (green). Note the absence of VMAT2 immunolabeling in the GS-positive astrocytes of the VTA . In the ST, the VMAT2 signal in astrocytes is highlighted by white arrows. Scale bars: 20 μm. d Electron microscopy sections show the immunogold labelling of VMAT2 in L5 of a P30 rat. On the left: immunogold particles for VMAT2 in a dopaminergic axonal bouton making synapse with an asymmetric synapse (synaptic triad). VMAT2, 10 nm gold particles . On the right: immunogold particles for VMAT2 located in a peri-synaptic astrocytic process. VMAT2, 10 nm gold particles . Scale bars: 250 nm. Histograms show the average density of VMAT2 immunogold particles in astrocytic processes and axonal boutons in L5 of rat PFC. Note that, although lower than that of dopaminergic boutons (−73%, n = 3), the density of the VMAT2 immunogold particles is significantly higher (+82%, n = 3) than the background calculated on mitochondria. The error bars indicate the SEM