Slow firing | Burst firing | Fast firing | ||||
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Number of neurons | 18 | (4) | 15 | (5) | 61 | (9) |
Resting membrane potential (mV) | −56.3 ± 6.3† | (−51.9 ± 1.9) | −53.9 ± 6.5 | (−56.8 ± 3.8) | −51.7 ± 5.5 | (−53.8 ± 3.8) |
Input resistance (MΩ) | 370 ± 210 | (241 ± 221) | 273 ± 210 | (253 ± 191) | 320 ± 230 | (265 ± 131) |
Time constant (ms) | 17.5 ± 7.5 | (14.7 ± 11.6) | 12.2 ± 5.6 | (11.5 ± 4.5) | 14.4 ± 7.2 | (14.4 ± 8.3) |
Instantaneous firing frequency (Hz) | 19.4 ± 15.4* | (23.8 ± 11.4) | 123.9 ± 54‡ | (124.4 ± 5.4) | 45.1 ± 29.9 | (56.1 ± 29.9) |
Steady firing frequency (Hz) | 9.4 ± 3.1* | (12.5 ± 4.2) | 18.2 ± 7.7 | (16.0 ± 4.2) | 20.5 ± 9.8 | (23.0 ± 10.9) |
Action potential amplitude (mV) | 72.3 ± 12.1* | (67.2 ± 9.8) | 85.8 ± 15.8 | (97.5 ± 7.3) | 88.7 ± 16.3 | (84.6 ± 16.9) |
Action potential half-width (ms) | 1.5 ± 0.5* | (1.5 ± 0.1) | 0.9 ± 0.2 | (0.7 ± 0.1) | 0.8 ± 0.3 | (1.0 ± 0.4) |
Fast AHP amplitude (mV) | – | – | 20.3 ± 10.9 | (21.2 ± 10.4) | 20.3 ± 9.4 | (19.9 ± 8.8) |
Fast AHP duration (ms) | – | – | 2.5 ± 1.7 | (3.5 ± 2.6) | 2.4 ± 2.1 | (4.6 ± 4.0) |
Slow AHP amplitude (mV) | 17.4 ± 7.7* | (13.0 ± 6.8) | 10.9 ± 5.5 | (10.4 ± 1.5) | 12.2 ± 6.3 | (10.4 ± 4.5) |
Slow AHP duration (ms) | 267.1 ± 94.5† | (187 ± 61.4) | 275.4 ± 89.2 | (287 ± 89.1) | 218.6 ± 65.8 | (196.7 ± 49.4) |
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Input resistances and time constants were calculated from small hyperpolarizing current pulses (−20 pA). Instantaneous and steady firing frequencies were determined using a depolarizing current pulse from −60 mV. The size of the current pulse was that required to bring the membrane to threshold from −75 mV. Action potential measurements were taken using a long duration (700 ms) depolarization that brought the membrane to threshold from −60 mV. Statistical tests were performed on all cells. Significant differences (P < 0.05) are indicated:
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↵* slow firing versus burst firing and fast firing neurons.
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↵† slow firing versus fast firing neurons
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↵‡ burst firing versus slow firing and fast firing neurons. The numbers in parentheses represent values from antidromic cells.