Up-regulation of P2X4 receptors in spinal cord microglia is crucial for tactile allodynia, an untreatable pathological pain reaction occurring after peripheral nerve injury. How nerve injury in the periphery leads to this microglia reaction in the dorsal horn of the spinal cord is not yet understood. It is shown here that CCL21 was rapidly expressed in injured small-sized primary sensory neuron...

BACKGROUND AND PURPOSE This study was designed to clarify mechanisms responsible for the anti-allodynic effects of duloxetine in diabetes. EXPERIMENTAL APPROACH The streptozotocin-induced diabetic rat model was used to compare the efficacy of duloxetine, 5-HT, the 5-HT(2A) receptor agonist [1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane hydrochloride (DOI)] and two antagonists (ketanserin and ...

Cold allodynia is a complaint in patients with lumbar disc herniation (LDH), and significantly impairs their quality of life. We treated cold allodynia with continuous lumbar sympathetic nerve block (CLSNB) with patientcontrolled analgesia (PCA) and determined the therapeutic outcome in long-term follow-up. Eight patients with a median age of 52.0 years were enrolled between September 2013 and ...

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...