Morphine injections into the periaqueductal-periventricular gray attenuate septal hyperreactivity

Animals with septal lesion-induced reactivity were injected with 2 dose levels of morphine in the periaqueductal-periventricular gray. Both doses of morphine transiently attenuated the reactivity. Naloxone injected IP significantly antagonized the morphine attenuation of the septal-lesion induced reactivity.