Continuous perfusion with morphine of the orbitofrontal cortex reduces allodynia and hyperalgesia in a rat model for mononeuropathy.
Recent imaging reports demonstrate the activation of the orbitofrontal cortical (OFC) area during acute and chronic pain. The aim of this study was to compare the effects of chronic perfusion of this area with morphine on nociception in control rats and in rats subjected to mononeuropathy. Chronic perfusion of morphine, using miniosmotic pumps, produced significant and naloxone-reversible depression of tactile and cold allodynias and thermal hyperalgesia, observed in neuropathic rats, while it produced significant elevation and naloxone insensitive increase of acute nociceptive thresholds in control rats. The observed results support the idea that this area is a component of a flexible cerebral network involved in pain processing and perception.
Al Amin
Hassen A
HA
Department of Psychiatry, Faculty of Medicine, American University of Beirut, Beirut, Lebanon.
Atweh
Samir F
SF
Baki
Samah Abdel
SA
Jabbur
Suhayl J
SJ
Saadé
Nayef E
NE
D000701:Analgesics, Opioid / Q000627:therapeutic use*; D000818:Animals; D001522:Behavior, Animal; D004195:Disease Models, Animal; D004333:Drug Administration Routes; D004334:Drug Administration Schedule; D005625:Frontal Lobe / Q000187:drug effects* / Q000503:physiopathology; D006930:Hyperalgesia / Q000209:etiology; D020422:Mononeuropathies / Q000150:complications / Q000188:drug therapy*; D009020:Morphine / Q000627:therapeutic use*; D009270:Naloxone / Q000494:pharmacology; D009292:Narcotic Antagonists / Q000494:pharmacology; D010146:Pain / Q000188:drug therapy* / Q000209:etiology; D010147:Pain Measurement / Q000187:drug effects; D017288:Pain Threshold / Q000187:drug effects; D051381:Rats; D017207:Rats, Sprague-Dawley; D011930:Reaction Time / Q000187:drug effects; D013997:Time Factors
D000701:Analgesics, Opioid; D009292:Narcotic Antagonists; D009270:Naloxone; D009020:Morphine