The present study explored the interaction between histaminergic and opioidergic systems at the level of the hippocampus in modulation of orofacial pain by intra-hippocampal microinjections of histamine, pyrilamine (an antagonist of histamine H(1) receptors), ranitidine (an antagonist of histamine H(2) receptors), morphine (an opioid receptor agonist) and naloxone (an opioid receptor antagonist...

introduction: tanacetum sonbolii (asteraceae) is an endemic species in iran. in the present study, we examined the effects of tanacetum sonbolii hydroalcoholic extract on the formalin test in mice. methods: 126 swiss albino mice weighing 230-280g were used as subjects. the formalin test was performed on two control groups (marked as intact and saline groups n = 6 in each group) and an experimen...

Food deprivation produces analgesia. This response is reversed i.e. pain sensitivity is lowered, when the food deprived rats are fed. In the present study the effect of chronic pain on the motivation to get food, in food deprived rats, was observed. In ten rats the effect of formalin and morphine plus formalin on the motivation to get food was studied. Injection of formalin significantly (P < 0...

In the present study, we examined the effects of dopamine (DA) receptor antagonists infused into the nucleus accumbens septi (NAS) on analgesia induced by intra-ventral tegmental area (VTA) infusions of the substance P (SP) analog, DiMe-C7 or morphine and intra-NAS infusions of amphetamine. Rats received intra-NAS infusions of either the mixed DA receptor antagonist flupenthixol (1.5 or 3.0 mic...

We report an anatomically defined opioid-responsive site in the rostral agranular insular cortex (RAIC) of the rat and characterize the antinociception produced by morphine acting within this region. Immunohistochemistry for the mu-opioid receptor identified a discretely localized cluster of densely labeled dendrite-like processes in the agranular insular cortex. The antinociceptive effect of m...

introduction: pain as a complex process in the cns has been extensively studied by many researchers. it has been found that pain is controlled by certain pathways in the cns, one of most important of which is the descending noradrenergic system. the pathway begins with locus coeruleus (lc) nucleus and ends in the spinal cord. in this study, formalin test was used as a chemical and tonic pain te...

the involvement of supraspinal alpha-adrenergic receptors in tonic pain was assessed in formalin-induced pain in rats. the alpha2 adrenoceptor agonist clonidine, along with yohimbine and prazosin, α2 and α1 receptor antagonists, were introduced intracerebroventrically (icv) and/or systemically in different doses. the data show that 1) clonidine exerts an alpha adrenergic analgesic effect, in ad...

In this study, the antinociceptive effects of the gap junction blocker carbenoxolone and morphine were examined using the formalin test as a model of pain. We found that carbenoxolone was dose-dependently antinociceptive in both the first and second phases of the formalin test. Pretreatment with carbenoxolone increased antinociceptive effect of morphine in the first phase of formalin test. Also...

Problem statement: This study was performed to evaluate the effect of W7 (specific calmodulin inhibitor) on morphine induced analgesia in Adrenalectomized (ADX) rats by tail-flick test. Approach: Tolerance to morphine was induced in male Wistar rats by daily injections of morphine (15 mg kg, i.p) for 8 days. Adrenalectomy was performed under general anesthesia with intraperitoneal (i.p) injecti...