Background and Objective: Food deprivation increases the expression of orexin-1 receptor gene in the hypothalamus. On the other hand, food deprivation induces analgesia and orexin has a fundamental and well known role in pain modulation. This study aimed to determine the role of orexin receptor 1 antagonist in analgesic effect of acute food deprivation (12 h) by hot plate test in male rats. ...