Table 4.

A-type current as a function of age: isolation with TEA and recovery from inactivation at −100 mV

Age, days	Cm	Peak Amp	Density	TTP	Fit Peak	TTP Fit	τact	τinact	n
7.4 ± 1.3	13.0 ± 4.4	929 ± 452	55.9 ± 17.1	2.6 ± 0.3	649 ± 301	2.6 ± 0.4	0.68 ± 0.13	8.9 ± 1.3	8
29.5 ± 2.2	11.9 ± 5.7	1,662 ± 813	146.9 ± 77.0	2.3 ± 0.2	1,248 ± 504	2.5 ± 0.2	0.57 ± 0.08*	11.3 ± 0.4	7

Values are means ± SD for n cells. Week 1 = 7 ± 3 days; weeks 4–5 = 25–38 days combined. A-type current isolated by subtraction (recovery from inactivation). Recordings were made in the absence of extracellular Cd²⁺ and in the presence of 100 nM DTX, 30 nM MTX, and 30 mM TEA. Currents were elicited with a voltage step to +10 mV (recovery from inactivation protocol; see text). C_m, whole cell capacitance (pF); peak amp, peak amplitude of the A current (pA); density, peak amplitude of the A current/whole cell capacitance (pA/pF); TTP, time to peak (ms); fit peak, peak current determined by fit of Eq. 1 (pA) [this procedure removes residual DR current (after biophysical separation)]; TTP fit, TTP determined by fit of Eq. 1 (ms); τ_act, activation time constant (ms); τ_inact, inactivation time constant (ms)

^*Significant difference from week 1 (P < 0.05).