Figure 7. BDNF enhances the TTX-R I_Na in capsaicin-sensitive small diameter sensory neurons.

A, left, a representative recording of TTX-R I_Na obtained for voltage steps between −60 and +35 mV (in 5 mV increments) under control conditions. Right, after a 6 min exposure to 50 ng ml⁻¹ BDNF the amplitude of TTX-R I_Na was increased. B, left, summary of the effects of focally applied BDNF (50 ng ml⁻¹) on the current–voltage relation obtained from eight sensory neurons. The average current values after 2 and 6 min exposure to BDNF were significantly different from the control values for the voltages between −35 and +60 mV (RM ANOVA). Right, summary of the I/I_max–voltage relation in which the values of the current after BDNF treatment were normalized to their respective peak amplitude values for the control condition. The values of I/I_max after 2 and 6 min of BDNF were significantly different from their control values for voltages between −35 and +60 mV. C, left, the G/G_max–voltage relation for the control condition and after 6 min exposure to BNDF. Right, expansion of this relation for voltages between −30 and 0 mV where the asterisks represent a significant difference between the control values and after the 6 min BDNF treatment (RM ANOVA). In addition, the values of G/G_max were significantly different between the control and after 2 min exposure to BDNF for the voltages between −30 and −15 mV (data not shown).