Cyprodime (Tocris Biosciences, Bristol, UK) was used as a selective general m-opioid receptor antagonist. 9 A 5 mM stock solution was prepared by dissolving Cyprodime in 30% hydroxypropyl-β-cyclodextrin (Kleptose, 300 mg/mL, Apoteket, Stockholm, Sweden).
Naloxonazine (Tocris Biosciences, Bristol, UK), a derivate of naloxone, is a selective antagonist to m 1 . 10 A 1 mM stock solution was prepared by dissolving Naloxonazine in phosphate-buffered saline (NaCl 137 mM, KCl 2.7 mM, Na 2 HPO 4 10 mM, KH 2 PO 4 1.8 mM).
Naloxonazine (Tocris Biosciences, Bristol, UK), a derivate of naloxone, is a selective antagonist to m 1 . 10 A 1 mM stock solution was prepared by dissolving Naloxonazine in phosphate-buffered saline (NaCl 137 mM, KCl 2.7 mM, Na 2 HPO 4 10 mM, KH 2 PO 4 1.8 mM).