Table 2.

Statistical analysis of electrophysiological parameters in wild-type and Kv4.3−/− SNc DA neurons

	WT			Kv4.3^–/–
Parameter	Mean/median	SD/IQR	n	Mean/median	SD/IQR	n	p value (t test) (Mann–Whitney)
Passive properties
Rm (MΩ)	386.00	202.00	97	422.00	147.00	72	0.2351
Pacemaking
ISI (ms)	669.50	334.50	84	304.00	118.00	73	2.2 × 10^–16***
CV_ISI (%)	5.76	4.45	84	3.84	3.31	73	4 × 10^–4***
Postinhibitory rebound
Voltage sag (mV)	31.70	4.29	101	32.50	3.95	77	0.2082
Rebound delay (ms)	256.00	199.00	97	29.00	18.00	77	2.2 × 10^–16***
Action potential
AP threshold (mV)	–42.90	5.80	101	–41.60	4.00	77	0.15
AP amplitude (mV)	65.29	7.84	101	66.01	6.27	77	0.5024
AP half-width (ms)	1.29	0.24	101	1.40	0.33	77	0.038*
AP rise slope (mV/ms)	86.47	24.95	101	87.89	24.61	77	0.7049
AP decay slope (mV/ms)	–47.71	8.73	101	–45.33	8.89	77	0.0756
AHP trough V_m (mV)	–73.84	4.58	101	–73.83	3.58	77	0.9892
AHP latency (ms)	55.56	38.28	101	53.76	28.68	77	0.84
Excitability
Start frequency 100 pA (Hz)	7.23	3.98	98	10.68	3.73	77	4 × 10^–8***
Gain start (Hz/100 pA)	8.75	4.18	97	10.27	4.11	77	1.7 × 10^–3**
Gain end (Hz/100 pA)	3.41	1.61	76	3.11	1.69	66	0.37
SFA index	2.73	1.94	76	3.24	1.54	66	0.012*
I_A
V₅₀ inactivation (mV)	–68.91	5.10	87	–73.31	3.84	39	4.3 × 10^–6***
Inactivation tau (ms)	30.90	27.15	83	12.90	6.72	42	7.1 × 10^–12***
Amplitude (nA)	2.14	2.79	87	0.93	0.64	39	1.8 × 10^–12***
Charge (pA.s)	152.80	177.80	83	19.40	22.40	37	6.4 × 10^–15***
Charge density (pA.s/pF)	1.17	1.00	82	0.18	0.20	36	6.4 × 10^–13***
I_H
V50 activation (mV)	–88.41	4.24	75	–88.42	3.81	55	0.9886
Amplitude (pA)	453.00	212.50	75	575.30	275.80	57	6 × 10^–4***
Amplitude density (pA/pF)	3.49	1.93	74	5.76	2.36	54	7.6 × 10^–11***

The values for 16 electrophysiological parameters measured under current-clamp (corresponding to passive properties, spontaneous activity, postinhibitory rebound, action potential, and excitability) and eight electrophysiological parameters measured under voltage-clamp (corresponding to I_A and I_H properties) are presented for WT and Kv4.3^−/− SNc DA neurons. Mean and SD (black text) are reported for normally-distributed data, while median and interquartile range (IQR) are reported otherwise (italic text). Accordingly, statistical differences between WT and Kv4.3^−/− neurons were tested using a t test or a Mann–Whitney test, depending on the normality of the data. Asterisks indicate statistically significant differences (*p < 0.05, **p < 0.01, ***p < 0.001).