TABLE 5.
Electrophysiological properties of four clusters.
| Mean ± SEM | Cluster 1 (n = 10) | Cluster 2 (n = 22) | Cluster 3 (n = 8) | Cluster 4 (n = 10) | p-value (Kruskal-Wallis) |
| Resting membrane potential (mV) | −62.6 ± 1.4 | −65.8 ± 0.7 | −60.9 ± 3.0 | −68.7 ± 1.2 | χ2 = 10.36; p = 0.0157 *1–4 |
| Membrane resistance (MΩ) | 488 ± 86 | 224 ± 27 | 467 ± 100 | 125 ± 14 | χ2 = 22.9; p < 0.0001 ***1–4; **3–4; *1–2 |
| Membrane time constant (ms) | 39 ± 7 | 24 ± 3 | 28 ± 4 | 26 ± 2 | χ2 = 3.4; p = 0.34 |
| Rheobase (pA) | 10 ± 4 | 42 ± 9 | 14 ± 5 | 89 ± 19 | χ2 = 18.1; p = 0.0004 ***1–4; **3–4 |
| Sag Index (%) | 16 ± 4 | 21 ± 2 | 22 ± 4 | 25 ± 3 | χ2 = 4.7; p = 0.20 |
| Rebound Index (%) | −0.9 ± 8 | 34 ± 13 | 9 ± 9 | 88 ± 20 | χ2 = 18.5; p = 0.0003 ***1–4; **3–4 |
| AP threshold (mV) | −40.6 ± 1.2 | −46.6 ± 1.1 | −38.2 ± 1.4 | −43.9 ± 1.0 | χ2 = 19.5; p = 0.0002 ***2–3; *1–2; 3–4 |
| AP amplitude (mV) | 61.5 ± 4.0 | 83.7 ± 1.6 | 66.6 ± 3.2 | 80.0 ± 1.5 | χ2 = 29.5 p < 0.0001 ***1–2; 2–3; *1–4; 3–4 |
| AP duration at half-width (ms) | 1.17 ± 0.09 | 1.02 ± 0.04 | 0.82 ± 0.06 | 1.08 ± 0.08 | χ2 = 9.3; p = 0.0253 *1–3 |
| AP rise slope (mV.ms–1) | 71.7 ± 4.7 | 106.0 ± 2.3 | 86.7 ± 3.9 | 101.7 ± 4.6 | χ2 = 29.3; p < 0.0001 ***1–2; **1–4; 2–3 |
| AP decay slope (mV.ms–1) | 37.2 ± 3.3 | 60.5 ± 3.2 | 81.1 ± 8.5 | 57.4 ± 6.3 | χ2 = 19.4; p = 0.0002 ***1–3; **1–2 |
| AHP amplitude (mV) | 10.7 ± 1.3 | 13.6 ± 0.7 | 17.4 ± 1.4 | 13.2 ± 1.3 | χ2 = 11.5; p = 0.0094 **1–3 |
| fAHP amplitude (mV) | 7.5 ± 1.0 | 9.0 ± 0.9 | 16.8 ± 1.2 | 7.0 ± 1.3 | χ2 = 17.8; p = 0.0005 **1–3; 2–3;3–4 |
| ADP amplitude (mV) | 0.05 ± 0.05 | 0.52 ± 0.1 | 2.2 ± 0.5 | 1.7 ± 0.6 | χ2 = 14.7; p = 0.0021 **1–3; *1–4 |
| mAHP amplitude (mV) | 3.3 ± 0.7 | 5.1 ± 0.8 | 2.2 ± 0.6 | 7.9 ± 1.1 | χ2 = 12.4; p = 0.006 **3–4; *1–4 |
| AHP duration (ms) | 25.2 ± 4.1 | 35.4 ± 4.9 | 21.9 ± 4.2 | 148 ± 35 | χ2 = 11.3; p = 0.0104 *1–4; 3–4 |
| Firing rate at + 40 pA from rheobase (Hz) | 24 ± 2 | 15 ± 1 | 27 ± 3.4 | 8 ± 1 | χ2 = 24.8; p < 0.0001 ***1–4; 3–4; *1–2; 2–3 |
| Early spike frequency adaptation | 1.6 ± 0.1 | 1.5 ± 0.1 | 1.2 ± 0.1 | 3.3 ± 0.4 | χ2 = 26.3; p < 0.0001 ***2–4; 3–4; *1–4 |
| Late spike frequency adaptation | 2.6 ± 0.4 | 2.1 ± 0.2 | 1.5 ± 0.1 | 6.4 ± 1 | χ2 = 27.6; p < 0.0001 ***2–4; 3–4; *1–3 |
| I/O gain (Hz.pA–1) | 0.41 ± 0.04 | 0.27 ± 0.03 | 0.48 ± 0.07 | 0.15 ± 0.03 | χ2 = 21.4; p < 0.0001 ***3–4; **1–4; *2–3 |
| Spontaneous frequency (Hz) | 6.8 ± 3.0 | 1.7 ± 1.0 | 5.8 ± 3.7 | 0 | χ2 = 7.3; p = 0.062 |
All data: mean ± SEM. *p < 0.05; **p < 0.01; ***p < 0.001.