Table 3.

Values and statistical analysis of differences in membrane excitability parameters and quasi-steady-state I–V curve parameters before (control) and after application of SB-202190 together with TNF-α

	Control	TNF-α + SB202190	P Value	n
Membrane excitability parameters (assessed by current clamp)
Threshold, mV	−37.6 ± 1.4	−34.74 ± 2.69	ns	8
Rheobase, pA	230.6 ± 49.6	238.8 ± 52.5	ns	8
FSL (depolarizing ramp), ms	508.1 ± 98.5	559.1 ± 108.53	ns	8
(dV/dt)max, mV/ms	76.52 ± 10.2	58.6 ± 9.64	<0.01	8
AP count (depolarizing ramp)	11.37 ± 1.89	6 ± 1.95	<0.01	8
Quasi-steady state I–V curve parameters (assessed by voltage clamp)
Onset early phase, mV	−62.6 ± 0.9	−63.4 ± 1.5	ns	6
Peak early phase, mV	−38.6 ± 0.9	−40.9 ± 1	<0.05	6
Charge density from −70 mV to −40 mV	625 ± 88	725 ± 116	<0.05	6

Values are means ± SE; n, no. of neurons. Data describing threshold and rate of change of membrane potential with respect to time [(dV/dt)_max] were obtained from phase plots of changes in membrane voltage following application of 10-ms rectangular current steps. Data describing FSL and AP count were obtained following 1,500-ms depolarizing ramps. Data describing the rheobase were obtained following 500-ms rectangular current steps. Data describing the parameters of quasi-steady-state current-voltage (I–V) curves were obtained in voltage clamp recording, following application of slow (0.036 mV/ms, 2.5 s, Fig. 3D) voltage ramps. Data were analyzed using two-tail paired t-tests. The parameters which changed significantly are bolded. Note that application of SB202190 together with TNF-α lead to a significant decrease in (dV/dt)_max and AP count. ns, P > 0.05.