2.5. Naloxone-Precipitated Withdrawal and Tissue Collection

On the final day of TBC, mice were removed from their home cages, injected with naloxone HCl (1 mg/kg i.p., in 0.9% saline), placed in a Plexiglass tube (16 in tall x 6 in diameter), and monitored for paw tremors, wet dog shakes, jumps, mastication, and diarrhea for 30 min. Global withdrawal scores were calculated using the following equation: 0.8x(# of jumps) + 1x(# of wet dog shakes) + 0.35x(# of paw tremors) + 1.5x(diarrhea present each 5 minute bin) + 1.5x(mastication present each 5 minute bin) (Raehal and Bohn, 2011).