Figure 6.

Immunolabeling for CB₂ receptors (CB₂r) and neuronal nuclei (NeuN) in the ventral tegmental area (VTA) and the nucleus accumbens (NAcc) and for CB₂r and glial fibrillary acidic protein (GFAP) in the VTA of wild-type (WT) and CB₂r overexpressing (CB₂xP) mice. Confocal photomicrographs showing immunolabeling for CB₂r (red cells in (a) and (d)) and NeuN (green cells in (b) and (e)) in the VTA of WT and the NAcc of CB₂xP mice. Double labeling (yellow cells in (c) and (f)) both in the VTA and the NAcc indicates that most of the CB₂r immunoreactive (i.r.) cells are neurons. A CB₂r cell not labeled for NeuN is shown in (c) (arrow). (g–l) Immunolabeling for CB₂r (red cells in (g) and (j)) and GFAP (green cells in (h) and (k)) in the VTA of WT and CB₂xP mice. Double labeling (yellow cells in (i) and (l)) shows that most of the GFAP i.r. astrocytes are also immunolabeled for CB₂r (arrows in (i) and (l)). GFAP i.r. astrocytes not CB₂r i.r. can be rarely seen (arrow head). CB₂r immunolabeled cells, most probably neurons, are showed in (i) and (l) (double arrow). Same scale for (b–l).