Intrathecal neutralization of BDNF attenuates behavioral responses to noxious stimulation in CP. A, Von Frey filament response from before and after intrathecal infusion of control IgG in TNBS-treated rats. Plot of mean number of responses (of 10 applications per filament). These data show increase in responses after control IgG treatment (P < 0.001) in animals with CP. B, Von Frey filament response from before and after intrathecal infusion of anti-BDNF in TNBS-treated rats. Intrathecal infusion of anti-BDNF significantly reduced the response activity of animals with CP during VFF testing (P < 0.001). C, Response to graded electrical stimulation before and after intrathecal infusion of control IgG in TNBS-treated rats. Number of nocifensive responses during 5 minutes of electrical stimulation of pancreas before and after infusion of control IgG. Although a robust response was seen in electrical stimulation in all animals, no significant differences in response numbers were observed after infusion compared with experiments before infusion. D, Response to graded electrical stimulation from before and after intrathecal infusion of anti-BDNF in TNBS-treated rats. Number of nocifensive responses during 5 minutes of electrical stimulation of pancreas before and after infusion of anti-BDNF. Animals had significantly fewer responses to electrical stimulation after intrathecal infusion of anti-BDNF (P < 0.01).