08/01/1981 - "Morphine, levonantradol, and N-methyllevonantradol also produced dose-related increases in response latency both in the presence and absence of shock; increases in response latency were greater in the absence of shock than in the presence of shock."
08/01/1981 - "Levonantradol (0.017-0.03 mg/kg) and N-methyllevonantradol (0.01-0.017 mg/kg) only decreased the percentage of correct responses at the lower shock intensity, Neither morphine, levonantradol, nor N-methyllevonantradol consistently decreased the percentage of correct responses in the absence of shock. "
08/01/1981 - "Effects of morphine, levonantradol, and N-methyllevonantradol on shock intensity discrimination."
08/01/1981 - "The effects of morphine, levonantradol, and N-methyllevonantradol administered to squirrel monkeys by intramuscular injection were examined on an electric shock discrimination test. "
|1.||Morphine (MS Contin)