Satinder K P
Psychopharmacology (Berl). 1976 Jul 28;48(2):235-7. doi: 10.1007/BF00423267.
Effects of morphine administration were investigated on avoidance behavior in five rat strains. Strain-dependent facilitation or suppression of avoidance acquisition was found in animals tested 1 h after the last administration of morphine. Significant strain differences were found in the incidences of sexual stimulation, diarrhea and wetness, reactivity, and death due to toxicity.