Background and Aims: It is well-recognized that endogenous opioidergic system plays an important role in pain sensitivity, pain perception, and response to some stressing situations. The present study examined the probable role of endogenous opioidergic system in effects of food deprivation on formalin-induced nociceptive behaviors in male and female rats. Methods: To make short-term food d...

Objective: In this study, it was aimed to investigate the antinociceptive activity potential of Tofisopam and elucidate possible involvement opioid system in effect.Material Method: The efficacy (25 50 mg/kg) evaluated by hot-plate acetic acid-induced writhing tests; while effects drug on motor coordination mice were with Rota-rod tests.Result Discussion: at a dose mg/kg significantly prolonged...

introduction: feverfew (tanacetum parthenium) (t.p.) is widely used in folk medicine to treat many diseases. we reported the analgesic effect of t.p. flower and leaf previously. present study is designed to find the mechanism underlying the anti-nociceptive effect of the aqueous extract of t.p. flower. method: based on our previous study, the dose 50 mg/kg i.p. of the t.p. aqueous extract had a...

BACKGROUND Several investigations have indicated that cholestasis decreases opioid receptor expression in the brain following increased opioidergic neurotransmission. The opioidergic system plays an important role in regulation of reward circuits that may be produced via dopamine-dependent mechanisms. It has been suggested that the dopaminergic system of the nucleus accumbens is necessary in co...

Placebo analgesia involves the endogenous opioid system, as administration of the opioid antagonist naloxone decreases placebo analgesia. To investigate the opioidergic mechanisms that underlie placebo analgesia, we combined naloxone administration with functional magnetic resonance imaging. Naloxone reduced both behavioral and neural placebo effects as well as placebo-induced responses in pain...

PURPOSE Obese individuals vary in their experience of food cravings and tendency to engage in reward-driven eating, both of which can be modulated by the neural reward system rather than physiological hunger. We examined two predictions in a sample of obese women: (1) whether opioidergic blockade reduced food-craving intensity, and (2) whether opioidergic blockade reduced an association between...

Ligand-PET studies are attracting increasing interest in experimental and clinical research. As the most elaborated of PET techniques, ligand-PET allows the demonstration of receptor distributions, and thus, the delineation of neurochemical pathologies in the disease state. Recent developments are promising that ligand-PET will even allow to characterize dynamic and short-term changes in neurot...

Opioids modulate the affective component of pain and in vivo data indicate that opioids induce activation changes in the rostral ACC, insula and other brain areas. Hence, opioidergic release is to be expected in these brain regions following experimental pain stimulation. We examined healthy volunteers during heat pain and control subjects during rest using [18F]fluorodiprenorphine-PET. Pain st...