Table 3.
Electrophysiological properties of newly generated and mature dentate granule cells
| Electrophysiological property | Newly generated granule cells | n | Mature granule cells | n | Statistical significance (P) |
|---|---|---|---|---|---|
| Resting potential (mV) | −69.7 (1.7) | 9 | −74.8 (1.1) | 27 | 0.06 |
| Input resistance (MΩ) | 350 (37) | 11 | 388 (37) | 25 | 0.62 |
| Time constant (ms) | 16.6 (4.0) | 11 | 33.7 (3.7) | 25 | 0.003 |
| Membrane capacitance* (pF) | 42.3 (10.2) | 11 | 99.2 (12.7) | 25 | 0.003 |
| Spiking threshold (mV) | −45.8 (2.9) | 13 | −39.6 (1.5) | 27 | 0.07 |
| Firing rate† (Hz) | 27.5 (2.6) | 10 | 29.9 (4.8) | 14 | 0.65 |
| Spontaneous activity‡ (Hz) | 1.6 (0.8) | 6 | 0.80 (0.19) | 9 | 0.33 |
Experiments on newly generated neurons (GFP+) were carried out 4–8 weeks after viral injection. Data are presented as means, with s.e.m. in parentheses. The column on the right shows the statistical significance, calculated using a t-test.
*
Calculated from the input resistance and the time constant, as Cm = τm/Rin.
†
Measured in response to a 100-pA depolarizing current step.
‡
Spontaneous postsynaptic responses measured in voltage or current clamp.