behaviors have already been demonstrated. Systemic morphine inhibited both the early and late phases of the formalin-induced licking responses, and this action was naloxone-sensitive (Dubuisson & Dennis, 1977; Oluyomi, Hart, & Smith, 1992) as well. It has been shown that wide variety of brain regions including the frontal lobe, anterior cingulate cortex, insula, amygdala, hypothalamus, periaque...
