Fig. 4From: Antinociceptive tolerance to NSAIDs in the anterior cingulate cortex is mediated via endogenous opioid mechanismPretreatment with naloxone before microinjections of NSAIDs into the ACC results in prevention of NSAID-induced antinociception in HP latency for diclofenac (b), ketorolac (c), and xefocam (d), respectively. Control experiments of pretreatment with naloxone before microinjection of saline into the ACC do not significantly change HP latency (a)Back to article page