Table 3.
Electrophysiological properties of sampled cortical pyramidal neurons
| Pyramidal neuron group |
||||||
|---|---|---|---|---|---|---|
| L2/3 (n = 5) | L4 (n = 5) | L5a (n = 3) | L5b (n = 5) | L6+ (n = 5) | L6− (n = 5) | |
| Resting membrane potential (mV) | −73.0 ± 2.6 | −68.0 ± 7.4 | −61.5 ± 7.6 | −64.8 ± 8.7 | −68.4 ± 3.7 | −66.2 ± 7.0 |
| Membrane time constant (ms) | 11.5 ± 2.6 | 7.5 ± 4.5 | 11.5 ± 4.6 | 11.7 ± 5.1 | 9.8 ± 3.0 | 7.9 ± 2.6 |
| Input resistance (MΩ) | 51.1 ± 27.5 | 68.3 ± 28.8 | 65.3 ± 34.4 | 48.7 ± 29.5 | 62.2 ± 18.1 | 48.1 ± 11.8 |
| Action potential (AP) threshold (mV) | −47.6 ± 7.9 | −41.3 ± 15.6 | −40.2 ± 7.2 | −50.6 ± 10.5 | −41.4 ± 5.1 | −43.1 ± 7.1 |
| AP height (mV)a | 96.2 ± 8.0 | 103.8 ± 10.2 | 85.9 ± 10.0 | 97.9 ± 5.7 | 89.4 ± 6.4 | 94.0 ± 16.8 |
| AP half width (ms) | 0.85 ± 0.24 | 0.86 ± 0.39 | 0.88 ± 0.18 | 0.72 ± 0.29 | 0.77 ± 0.16 | 0.71 ± 0.13 |
| Fast afterpotential (mV)b | 2.7 ± 2.8*,‡‡‡ | −1.5 ± 2.0††,‡ | −3.9 ± 3.0††† | 4.9 ± 2.6‡‡‡ | −6.1 ± 3.3††† | −1.1 ± 3.0†,‡ |
| Slow afterpotential (mV)b | −1.2 ± 1.3 | −1.6 ± 1.0 | −4.9 ± 0.7 | −2.5 ± 4.4 | −2.4 ± 3.3 | −3.3 ± 1.9 |
*,†,‡Significant differences (*,†,‡p < 0.05;††p < 0.01;†††,‡‡‡p < 0.001 by Peritz's F test) from the value of L5a, L5b, or L6+ neurons, respectively.
aAP height was measured from resting membrane potential.
bFast and slow afterpotential was measured from baseline prior to action potential evoked by a short (< 5 ms) depolarizing pulse, at 3.3 ms or 29 ms from action potential onset, respectively. Pulse response without action potential to the same depolarizing pulse was recorded in another trace and subtracted. Our previous study showed that one type of L6 pyramidal neurons has a peak of fast afterhyperpolarization (AHP) at 3.3 ms on average, and that another type of L6 pyramidal neurons lacks fast AHP and has a peak of medium-range AHP at 29 ms on average (Kaneko et al., 1995).