Articles: hyperalgesia.
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Age-related changes occur in both the peripheral and central nervous system, yet little is known about the influence of chronic pain on pain sensitivity in older persons. The aim of this study was to investigate pain sensitivity in elders with chronic neck pain compared to healthy elders. ⋯ The presence of pain hypersensitivity in elderly women with chronic neck pain appears to be dependent on types of painful stimuli. This may reflect changes in the peripheral and central nervous system with age.
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Most migraineurs develop cutaneous allodynia (CA) during migraine, and the underlying mechanism of CA in migraine is thought to be sensitization of the third-order trigeminovascular neurons in the posterior thalamic nuclei. This study aimed to investigate whether the ascending/descending pathway associated with the thalamus is disturbed in migraineurs with CA (MWCA) using effective connectivity analysis of resting-state functional magnetic resonance imaging. ⋯ MWCA demonstrated disrupted effective connection pathways between the PTH and other cortical or subcortical regions that participated in multi-dimentional pain processing. Our findings highlight the dysfunctional ascending and descending pain network at the thalamic-level and may help to illuminate the possible pathophysiologic mechanisms of CA.
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Neuroscience letters · Jan 2015
Antiallodynic effect through spinal endothelin-B receptor antagonism in rat models of complex regional pain syndrome.
Complex regional pain syndrome (CRPS) is a very complicated chronic pain disorder that has been classified into two types (I and II). Endothelin (ET) receptors are involved in pain conditions at the spinal level. We investigated the role of spinal ET receptors in CRPS. ⋯ Intrathecal BQ 788 decreased the spinal ET-1 level. These results suggest that ET-1 is involved in the development of mechanical allodynia in CRPS. Furthermore, the ET-B receptor appears to be involved in spinal cord-related CRPS.
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Neuroscience letters · Jan 2015
Rosuvastatin attenuated the existing morphine tolerance in rats with L5 spinal nerve transection through inhibiting activation of astrocytes and phosphorylation of ERK42/44.
Recent studies suggested that statins have anti-inflammatory effects beyond their lipid-lowering properties. In the present study, we sought to investigate whether rosuvastatin could alleviate morphine tolerance by attenuating the glia mediated neuroinflammation in the spinal cord. Using a rat model of L5 spinal nerve transection, on day 8 after surgery morphine (10 mg/kg) was injected subcutaneously twice daily for consecutive 10 days. ⋯ Rosuvastatin administration for 5 days could restore morphine antinociceptive effect significantly. Additionally, the activation of astrocytes, the phosphorylation of extracellular signal-regulated kinase 42/44 (ERK(42/44)) and the expressions of TNFα and IL-1β were inhibited significantly by rosuvastatin. Our data suggested that rosuvastatin was a promising choice to treat neuropathic pain in combination with morphine.
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Chronic pain is a major health issue and most patients suffer from spontaneous pain. Previous studies suggest that Huperzine A (Hup A), an alkaloid isolated from the Chinese herb Huperzia serrata, is a potent analgesic with few side effects. However, whether it alleviates spontaneous pain is unclear. ⋯ The same effects occurred when Hup A was infused into the anterior cingulate cortex. Furthermore, ambenonium chloride, a competitive inhibitor of acetylcholinesterase, also increased the paw-withdrawal threshold but failed to induce place preference in CPP. Therefore, our data suggest that acetylcholinesterase in both the peripheral and central nervous systems is involved in the regulation of mechanical allodynia but not the spontaneous pain.