Basic membrane properties of orexin neurons in the orexin/EGFP, OE-OX1R−/−, and OE-OX2R−/− mice
| Orexin/EGFP (n = 10–20) | OE-OX1R−/− (n = 10–24) | OE-OX2R−/− (n = 13–35) | |
|---|---|---|---|
| Number of orexin-ir neurons | 620 ± 148 (n = 4) | 682 ± 88 (n = 4) | 583 ± 78 (n = 4) |
| Capacitance (pF) | 24.0 ± 2.5 | 27.6 ± 2.1 | 24.0 ± 1.0 |
| Resting membrane potential (mV) | −60.1 ± 1.0 | −59.8 ± 1.1 | −59.2 ± 2.2 |
| Membrane resistance (MΩ) | 579.3 ± 28.0 | 592.5 ± 34.8 | 546.0 ± 27.8 |
| Spontaneous firing frequency (Hz) | 2.3 ± 0.3 | 2.3 ± 0.3 | 2.6 ± 0.2 |
| Action potential peak | 29.0 ± 2.4 | 28.6 ± 3.2 | 29.3 ± 2.2 |
| Action potential amplitude | 61.2 ± 3.2 | 61.8 ± 3.5 | 62.8 ± 2.9 |
| Half-width (ms) | 4.0 ± 0.4 | 3.5 ± 0.4 | 3.3 ± 0.3 |
| sEPSC frequency (Hz) | 4.5 ± 0.8 | 4.1 ± 0.8 | 3.5 ± 0.5 |
| sEPSC amplitude (pA) | 28.9 ± 1.4 | 27.1 ± 1.2 | 32.5 ± 3.1 |
| sIPSC frequency (Hz) | 1.7 ± 0.3 | 1.1 ± 0.3 | 1.1 ± 0.2 |
| sIPSC amplitude (pA) | 17.3 ± 0.9 | 21.5 ± 1.5 | 18.5 ± 1.6 |
All parameters were determined by whole-cell slice patch-clamp recordings from orexin neurons with the exception of the number of orexin-ir neurons and spontaneous firing frequency. The number of orexin-ir neurons was counted in every fourth coronal brain section (40 μm) throughout the entire brain. The spontaneous firing frequency was determined by loose cell-attached recordings.