Figure 5. Effects of 5–6 days of IL-1β exposure on I_Ba in medium-diameter DRG neurons.

A, I–V plot shows that IL-1β exposure results in a slight increase in average I_Ba density in neurons studied from V_h = −100 mV. B, by contrast, when V_h = −60 mV I–V plots reveal a significant reduction in averaged I_Ba peak density (V_cmd = −10 mV) in neurons exposed to IL-1β (from −58 ± 6 pA pF⁻¹, n = 10 to −38 ± 4 pA pF⁻¹, n = 11; P < 0.01). C, representative traces illustrating currents and voltage protocols used to determine voltage dependence of inactivation. D, single Boltzmann function fitting of curves for the voltage dependence of inactivation reveal that IL-1β exposure led to a significant leftward shift (hyperpolarizing shift in I_Ba inactivation) in the values for V_1/2 (illustrated by dotted line with arrowhead), whereas slope factor was unaffected. Error bars indicate means ± SEM. Significant difference versus control *P < 0.05, ^†P < 0.01 and ^§P < 0.001 with unpaired t test.