Protocol of morphine administration

Acutely treated mice (= 9) were injected with a single dose of morphine (20 mg/kg, subcutaneously). Chronically treated animals (= 9) were injected with increasing doses of morphine for 5 days (10, 20, and 40 mg/kg, subcutaneously; see Materials and methods). Control (= 9) and acute morphine groups received injections of saline in the same time schedule as the chronic group received morphine. Animals were killed by decapitation 4 hours after the last injection. The time point used for tissue collection and gene expression analysis is indicated by the red arrow.<b>Copyright information:</b>Taken from "Morphine effects on striatal transcriptome in mice"http://genomebiology.com/2007/8/6/R128Genome Biology 2007;8(6):R128-R128.Published online 28 Jun 2007PMCID:PMC2394777.