Cell type | ||||
---|---|---|---|---|
Normally adapting | Nonadapting | Strongly adapting | Granule cells | |
Threshold, mV | −40.2 ± 1.7 | −40.5 ± 2.5 | −36.2 ± 3.4 | −48.1 ± 1.42 |
Amplitude, mV | 57.9 ± 2.9 | 59.0 ± 6.5 | 69.0 ± 4.9 | 109.7 ± 4.33 |
Duration, msec | 2.4 ± 0.2 | 1.6 ± 0.11 | 2.1 ± 0.3 | 2.1 ± 0.1 |
Duration at 0.5 amp, msec | 1.13 ± 0.07 | 0.86 ± 0.11 | 1.10 ± 0.11 | 1.07 ± 0.06 |
Rise, dV/dt | 743.7 ± 63.8 | 887.3 ± 198.0 | 751.0 ± 146.8 | 1876.3 ± 168.64 |
Decay, dV/dt | 397.2 ± 42.8 | 510.7 ± 133.2 | 452.0 ± 103.8 | 784.0 ± 59.84 |
dV/dt ratio | 2.04 ± 0.14 | 1.84 ± 0.15 | 1.81 ± 0.34 | 2.50 ± 0.23 |
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This table compares action potential properties of the three classes of interneurons based on spike frequency adaptation. Shown are spike threshold, spike amplitude measured from resting membrane potential, spike duration measured from the onset of rise to the point where the membrane potential returned to the level seen at the onset of the spike (duration), spike duration measured at a point halfway between the potential at which the spike began to rise and its peak (duration at 0.5 amp), the maximum rate of rise of the spike potential (rise, dV/dt), the maximum rate of decay or repolarization of the spike (decay, dV/dt), and the ratio of the maximum rate of rise to the maximum rate of decay (dV/dt ratio). 1The spike duration was significantly shorter in nonadapting interneurons than in normally adapting interneurons and granule cells (p < 0.05), but no other differences were seen among the three different adaptation groups. 2Regarding differences of interneurons and granule cells, the threshold of granule cells was significantly more hyperpolarized than normally adapting, strongly adapting (p < 0.01), and nonadapting (p < 0.05) interneurons. 3The amplitude of granule cell spikes was significantly greater than all interneurons (p < 0.001) and 4the rise and decay of granule spikes were significantly faster than all interneurons (p < 0.01).