effects of insulin (1, 2 and 3 iu/kg, i.p.), morphine (5mg/kg, i.p.), naloxone (5mg/kg, s.c.), insulin before morphine and after naloxone were studied in the formalin test of mice. formalin test was induced by intraplantar injection of formalin (20m, 5%). morphine alone and insulin with morphine decreased the first phase (0-5 min) of pain. naloxone increased the interphase (6-20 min) of nicicep...

BACKGROUND The roles of descending facilitatory pathway from the rostral medial medulla (RMM) in development of persistent spontaneous nociception and hyperalgesia were evaluated in the bee venom (BV) test and the formalin test. METHODS Bilateral lesions of the RMM with ibotenic acid, a soma-selective neurotoxin, were performed to study their effects on the spontaneous pain-related behaviors ...

Calcium, through its various channels involves in local, spinal and supra-spinal transmission of pain. In the present study, we investigated the separate and combined treatment effects of verapamil (a calcium channel blocker), morphine (an opioid agonist) and naloxone (an opioid antagonist) on pain in the orofacial region of rats. Orofacial pain was induced by subcutaneous (SC) injection of for...

To investigate the effect of N-methyl-D-aspartate (NMDA) receptor antagonist MK-801 on the formalin-induced cyclooxygenase-2 (COX-2) expression in the dorsal horn of the rat spinal cord. Forty-eight male Sprague-Dawley rats were divided into 4 groups: control, formalin, formalin+normal saline (NS) and formalin+MK-801 groups. Rats in formalin, formalin+NS and formalin+MK-801 groups were subcutan...

introduction: although formalin-induced activity in primary afferent fibers and spinal dorsal ‎horn is well described, the midbrain neural basis underlying each phase of behavior in ‎formalin test has not been clarified. the present study was designed to investigate the nucleus ‎cuneiformis (cnf)‎‏ ‏neuronal responses during two phases after subcutaneous injection of ‎formalin into the hind paw...

The present study investigated the effects of intra-dentate gyrus microinjection of naloxone (an opioid antagonist) and thioperamide (an antagonist of histamine H3 receptors) in the formalin test in rats. Subcutaneous injection of formalin (50 μl, 2.5 %) in the ventral surface of right hind paw produced a biphasic pattern (first phase: 0-5 min and second phase: 15 60 min) of licking/biting and ...