Numerous human and animal studies indirectly implicate neurons in the anterior cingulate cortex (ACC) in the encoding of the affective consequences of nociceptor stimulation. No causal evidence, however, has been put forth linking the ACC specifically to this function. Using a rodent pain assay that combines the hind-paw formalin model with the place-conditioning paradigm, we measured a learned...

Identification of the brain areas that contribute to pain is an essential undertaking towards understanding persistent pain. Areas of the basal ganglia have been proposed to play important roles in nociception as previous studies have determined the involvement of the substantia nigra pars compacta and the dorsolateral striatum in pain. The purpose of the present study was therefore to expand u...

D-amino acid oxidase (DAO) is an enzyme catalyzing oxidative deamination of neutral and polar d-amino acids and is expressed in the kidneys, liver, and central nervous system (CNS) including the spinal cord. We have previously demonstrated that DAO gene deletion/mutation by using mutant ddY/DAO(-/-) mice and systemic administration of the DAO inhibitor sodium benzoate blocked formalin-induced h...

In the present study, effects of intracerebroventricular (icv) administration of histamine, mepyramine (H1-receptor antagonist) and famotidine (H2-receptor antagonist) have been investigated on the formalin test in rats. Subcutaneous injection of formalin (50 microl, 1%) into the ventral surface of the left hind paw produced a marked biphasic pain response (first phase: 0-5 min and second phase...

  In the present study, the effect of contralateral and bilateral electrolytic lesions of the nucleus reticularis paragigantocellularis (PGi) on tonic pain was assessed in rats. Pain-related behavior was evaluated using the formalin test 7 days after the lesion was made. PGi lesions did not produce any marked changes in the early phase of the formalin test, but significantly increased pain sens...

Objective(s): Intracerebroventricular injection of orexin-A (hypocretin-1) antagonist has been shown to inhibit stress-induced analgesia. However the locations of central sites that may mediate these effects have not been totally demonstrated. This study was performed to investigate the role of rostral ventromedial medulla (RVM) orexin receptor 1 in stress-induced analgesia (SIA). Materials and...

objective: to investigate the effect of intracerebroventricular injection of histamine on pain induced by subcutaneous iniection of formalin in the left ear of rabbit and the effect of the amine on morphine analgesia and naloxone hyperalgesia. design: experimental study. animals: sixty - six male new zealand white rabbits weighing 2.640.16kg. procedure: intracerebroventricular injections of the...

Introduction: Uncoupling protein 2 (UCP2) in the inner mitochondrial membrane changes the activity of KATP channels and the cell excitability, probably by decreasing the ATP production. Given the expression of UCP2 in primary afferent neurons, and the importance of these channels in morphine-induced analgesia, genipin, an UCP2 inhibitor, may affect these processes, when administrated intrath...

post operative pain and its control remains one of the most important issues in the field of surgery and health care system. formalin test has been used as a method for assessing pain and analgesia in rats. systemic and spinally administered clonidine, an ?2-adrenergic agonist, is proved to enhance postoperative analgesia. it has also been shown that morphine-dependent rats experience more chro...

The formalin test is a model of injury-produced inflammatory pain. Anesthetics, in clinically relevant concentrations, affect neutrophils and immune suppression. This study was to determine whether halothane reliably inhibits inflammatory reaction and formalin induced pain behavior or does not. Rats were exposed to 100% oxygen (control) or halothane, respectively for 30 min and then 24 hr later...