Differential effect of brain-derived neurotrophic factor on high-thresholdmechanosensitivity in a rat neuropathic pain model

We investigated the effect of the systemic infusion of brain derived neurot rophic factor (BDNF) on the behavioral response in a rat neuropathic pain m odel. One microgram per hour infusion of BDNF significantly attenuated mech anical hyperalgesia tested by the pin-prick test, however, 20 mu g/h-BDNF i nfusion, on the contrary, enhanced the response. Neither 0.5 nor 10 mu g/h- BDNF infusion influenced the mechanical hyperalgesia. Mechanical allodynia and thermal hyperalgesia, tested using a von Frey filament (23.0 mN) and th e plantar test, were not influenced by BDNF treatment. These data suggest t hat systemic BDNF treatment can specifically alter high-threshold mechanose nsitivity, (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.