Recent animal studies on the mechanism of migraine show that intracranial pain is accompanied by increased periorbital skin sensitivity. These findings suggest that the pathophysiology of migraine involves not only irritation of meningeal perivascular pain fibers but also a transient increase in the responsiveness (ie, sensitization) of central pain neurons that process information arising from...

The present experiments examined the role of spinal proinflammatory cytokines [interleukin-1beta (IL-1)] and chemokines (fractalkine) in acute analgesia and in the development of analgesic tolerance, thermal hyperalgesia, and tactile allodynia in response to chronic intrathecal morphine. Chronic (5 d), but not acute (1 d), intrathecal morphine was associated with a rapid increase in proinflamma...

introduction: neuropathic pain can be very difficult to treat and it is one of the important medical challenging about pain treatments. muscimol as a new agonist of gamma-aminobutyric acid receptor type a (gaba a ) have been introduced for pain management. thus, the present study was performed to evaluate the pain alleviating effect of intrathecal injection of different doses of muscimol as gab...

Hypersensitivity resulting from nerve injury or morphine tolerance/hyperalgesia is predicted to involve similar cellular and molecular mechanisms. One expected but incompletely explored mechanism is the activation of central neuroimmune responses associated with these conditions. To begin to address this, we undertook three separate studies: First, we determined the acute antinociceptive action...

background: p2x4 receptor (p2x4r), a purinoceptor expressed in activated spinal microglia, plays a key role in the pathogenesis of neuropathic pain. spinal nerve injury induces up-regulation of p2x4r on activated microglia in the spinal cord, and blockade of this receptor can reduce neuropathic pain. the present study was undertaken to determine whether paroxetine, an inhibitor of p2x4r, could ...

Dynamic mechanical allodynia is a widespread and intractable symptom of neuropathic pain for which there is a lack of effective therapy. During tactile allodynia, activation of the sensory fibers which normally detect touch elicits pain. Here we provide a new behavioral investigation into the dynamic component of tactile allodynia that developed in rats after segmental removal of glycine inhibi...

BACKGROUND Nerve ligation injury in rats produces a pain syndrome that includes mechanical allodynia. Intrathecal administration of cholinesterase inhibitors or adenosine receptor agonists have anti-allodynic effects in this model. Therefore, we tested the interaction between intrathecal neostigmine and N(6)-cyclohexyladenosine (CHA) in a rat behavioral model of neuropathic pain. METHODS Male...

To test the possibility of a peroxisome proliferator activated receptor (PPAR) γ agonist to treat neuropathic pain, we examined the effects of pioglitazone, a PPARγ agonist, on tactile allodynia and expression of activated microglia in the dorsal horn of spinal cord using neuropathic pain model. The unilateral sciatic nerve was partially ligated (PSL) in male ICR mice. Pioglitazone (1-25 mg/kg ...

BACKGROUND Exogenous erythropoietin inhibits development of allodynia in experimental painful neuropathy because of its antiinflammatory and neuroprotective properties at spinal, supraspinal, and possibly peripheral sites. The authors assess the effect of a nonhematopoietic erythropoietin analog, ARA290, on tactile and cold allodynia in a model of neuropathic pain (spared nerve injury) in rats ...