Maturation of membrane, action potential, potassium current and sodium current properties.
E10–E12
E14–E16
E19–E21
ANOVA P
Membrane properties
RMP (mV)
-62.21 ± 10.31 (22)
-66.33 ± 6.87 (21)
-66.52 ± 8.49 (28)
P = 0.17 (Figure 1D)
Time constant tau (ms)
15.57 ± 6.23 (10)
5.90 ± 3.26 (13)
3.18 ± 1.33 (20)
P < 0.0001 (Figure 5B)
Input resistance (MΩ)
324.60 ± 120.30 (10)
211.40 ± 49.87 (13)
123.90 ± 49.90 (20)
P < 0.0001 (Figure 5C)
Cell capacitance (pF)
47.91 ± 4.61 (10)
26.78 ± 9.97 (13)
26.15 ± 4.60 (20)
P < 0.0001 (Figure 5D)
Action potential (AP) properties
Threshold current (pA)
121.30 ± 80.30 (22)
242.70 ± 68.58 (21)
321.70 ± 121.00 (28)
P < 0.0001 (Figure 1B)
Latency (ms)
19.49 ± 10.86 (22)
4.17 ± 1.15 (21)
3.00 ± 0.57 (28)
P < 0.0001 (Figure 2C)
Max rise rate (mV/ms)
38.59 ± 12.13 (22)
98.76 ± 40.98 (21)
155.60 ± 42.19 (28)
P < 0.0001 (Figure 2E)
Max fall rate (mV/ms)
-19.26 ± 5.78 (22)
-56.30 ± 25.85 (21)
-104.40 ± 29.79 (28)
P < 0.0001 (Figure 2F)
AP half width (ms)
4.57 ± 1.07 (21)
1.91 ± 0.93 (21)
0.97 ± 0.17 (28)
P < 0.0001 (Figure 2D)
AP reliability range (ms)
8.89 ± 8.98 (22)
0.44 ± 0.24 (21)
0.21 ± 0.14 (28)
P < 0.0001 (Figure 3C)
AP height (mV)§
69.09 ± 11.64 (22)
80.27 ± 8.83 (21)
82.94 ± 9.97 (28)
P < 0.0001
KV current (Ik)
Total Ik at +20 mV (pA)
3076 ± 1272 (35)
4386 ± 1105 (42)
6240 ± 1327 (39)
P < 0.0001 (Figure 6B)
Total Ik conductance (nS)
26.99 ± 11.16 (35)
38.47 ± 9.70 (42)
54.74 ± 11.64 (39)
P < 0.0001 (Figure 6C)
Total Ik density (pA/pF)
71.71 ± 26.75 (10)
172.00 ± 65.47 (13)
258.60 ± 65.62 (15)
P < 0.0001 (Figure 6D)
NaV current (INa)
V25% (mV)∧
-33.64 ± 4.99 (14)
-40.50 ± 5.57 (24)
-50.36 ± 6.02 (11)
P < 0.0001
INa (pA)*
-1728.00 ± 759.10 (14)
-2453.00 ± 654.00 (24)
-3386.00 ± 1089.00 (11)
P < 0.0001 (Figure 10B)
INa conductance (nS)*
24.15 ± 8.90 (14)
32.43 ± 7.51 (24)
44.97 ± 12.07 (11)
P < 0.0001 (Figure 11C)
INa density (pA/pF)*
-36.17 ± 13.99 (12)
-84.16 ± 48.52 (20)
-98.59 ± 53.48 (10)
P < 0.01 (Figure 11D)
Max rise rate (pA/ms)*
-4223.00 ± 2906.00 (14)
-7836.00 ± 3837.00 (24)
-10546.00 ± 5736.00 (11)
P < 0.01 (Figure 10C)
Max fall rate (pA/ms)*
1008.00 ± 735.00 (14)
1842.00 ± 776.80 (24)
2782.00 ± 1117.00 (11)
P < 0.0001 (Figure 10D)
Half width (ms)*
1.99 ± 1.03 (14)
1.29 ± 0.37 (24)
1.13 ± 0.14 (11)
P < 0.01 (Figure 10E)
Reliability range (ms)*
0.46 ± 0.42 (22)
0.39 ± 0.39 (23)
0.50 ± 0.42 (18)
P = 0.69 (Figure 10F)
V1/2 (mV)
-49.87 ± 3.20 (7)
-47.13 ± 5.27 (8)
-54.67 ± 3.77 (7)
P < 0.01 (Figure 11F)
RMP, Resting membrane potential. §Peak AP amplitude measured relative to the RMP. ∧Holding voltage 25% above activation voltage. *Measured at V25% for each developmental age.
