Neuroscience letters
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Neuroscience letters · Oct 1998
Nerve growth factor evokes hyperalgesia in mice lacking the low-affinity neurotrophin receptor p75.
Endogenous nerve growth factor (NGF) has been shown to be an important mediator of inflammatory pain and exogenous application of recombinant human NGF (rhNGF) produces pain and hyperalgesia in animals and humans. Since NGF can act through two receptors types, the high affinity tyrosine kinase A (trkA) receptor and the low affinity p75 receptor, we used transgenic mice lacking p75 to analyse the relative importance of these receptors. ⋯ Although animals lacking p75 have increased mechanical and thermal withdrawal thresholds they developed both heat and mechanical hyperalgesia after systemic injection of rhNGF whose magnitude did not differ significantly from wildtype animals. This means that NGF-induced hyperalgesia can occur in the absence of the p75 receptor and suggests that the trkA receptor is sufficient to mediate the acute noxious action of NGF.
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Neuroscience letters · Oct 1998
Increased ciliary neurotrophic factor expression in reactive astrocytes following spinal cord injury in the rat.
Expression of ciliary neurotrophic factor (CNTF) was observed in reactive astrocytes in injured spinal cord of the adult rat. After unilateral incision of the dorsal funiculus at a midthoracic level, the rats were sacrificed on the day of postoperation (DPO) 3, 7, 14 or 28. ⋯ Double immunofluorescence histochemistry revealed that all CNTF-like immunoreactive cells showed GFAP-like immunoreactivity. The CNTF upregulation in the reactive astrocytes may play important roles in repair process after spinal cord injury.