Fig. 3.

KOR-P co-localizes to GAD67⁺ cells while Pdyn^–/– mice do not exhibit KOR-P immunoreactivity unless injected with U50,488. a KOR-P immunoreactivity in the nucleus accumbens. b GAD67 immunoreactivity in the same region, c KOR-P co-localization with GAD67+ cells. Pdyn^–/– mice exhibited no KOR-P immunoreactivity above the background (d) while those injected with U50,488 showed KOR-P immunoreactivity (e), suggesting that kappa opioid receptors remain functional in Pdyn^–/– animals. f GFAP immunoreactivity for the Pdyn^–/– animal injected with U50,488. g Merged image of GFAP and KOR-P co-localization.