Neuroreport
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CEP-1347 inhibits the signalling pathway of c-jun-N-terminal kinase, and is neuroprotective in vivo and in vitro. Embryonic chick dorsal root ganglion neurones are dependent on NGF for survival and neurite outgrowth; NGF withdrawal results in apoptotic cell death. ⋯ When NGF was subsequently added to CEP-1347 treated explants, the outgrowth increased to a similar level to explants which had received NGF throughout. CEP-1347 may be a useful tool to maintain viable DRG explants to allow evaluation of neurite outgrowth promoting compounds and dissection of survival and neurite outgrowth signalling pathways.
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The cortical processing of allodynia (touch-evoked pain) resulting from neuralgia of the lateral cutaneous femoral nerve was investigated with a newly designed pneumatically driven brush by means of magnetoencephalography. Brushing the unaffected thigh produced subsequent activation of the contralateral primary somatosensory cortex (S1) with peak latencies of 37 and 56 ms. Brushing the affected side led to comparable activation of the contralateral S1 cortex. ⋯ Allodynia was also accompanied by an activation of the cingulate cortex, occurring only 92 ms. after stimulus onset, an observation suggesting an Abeta-fiber-mediated neuronal pathway involved in dynamic mechanical allodynia. This study corroborates the concept of cortical reorganisation underlying chronic pain. Furthermore, it demonstrates that a remarkable early activation of the cingulate cortex may be involved in the cortical processing of allodynia.
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Previous reports have shown that systemic administration of morphine can prevent the thermal hyperalgesia induced by the development of an osteosarcoma in C3H/HeJ mice after the implantation of NCTC 2472 cells. We show here that this type of hyperalgesia is also abolished by the local administration of morphine given at low doses (10 nmol), or the peripheral acting opioid receptor agonist loperamide (146 nmol). The analgesic effect of loperamide is prevented by the administration of the opioid receptor antagonist naloxone methiodide (10 mg/kg, i.p.), which is unable to cross the blood-brain barrier. These results provide evidence which supports the fact that peripheral opioids could be useful tools in the management of some types of cancer pain.