Intrinsic properties of cells by age and learning categories
| n (cells) | Rinput (MΩ) | Vrest (mV) | Vthresh (mV) | AP (mV) | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Y | A | Y | A | Y | A | Y | A | Y | A | |
| Learner | 12 | 15 | 71.6 ± 6.9 | 89.9 ± 6.0 | −65.3 ± 1.2 | −65.1 ± 1.4 | −46.3 ± 0.8 | −41.0 ± 1.4 | 108.2 ± 1.5 | 104.9 ± 2.1 |
| Nonlearner | 17 | 19 | 78.6 ± 5.9 | 86.0 ± 3.8 | −66.3 ± 0.8 | −66.1 ± 1.2 | −46.7 ± 1.0 | −42.8 ± 1.2 | 106.5 ± 1.4 | 106.3 ± 1.7 |
| Pseudoconditioned | 15 | 14 | 83.4 ± 4.8 | 97.7 ± 12.0 | −66.3 ± 1.2 | −64.6 ± 1.8 | −42.1 ± 1.9 | −38.9 ± 2.2 | 102.8 ± 1.6 | 105.4 ± 2.4 |
| Naive | 12 | 11 | 87.7 ± 6.5 | 102.5 ± 6.9 | −65.0 ± 1.2 | −64.8 ± 1.1 | −44.0 ± 2.2 | −44.2 ± 3.9 | 102.5 ± 2.8 | 105.6 ± 3.1 |
Input resistance was calculated from the steady-state membrane voltage during a brief −50 pA step. Resting membrane potential was defined as the membrane potential with no current injection. Action potential threshold was defined as the point at which the first derivative of the membrane potential equaled 20 mV/ms. Action potential height was measured as peak distance from the holding potential. There were significant differences in the threshold between young and aged cells in the learner and nonlearner groups (bold: learner, F (1,30) = 8.378, p < 0.01; nonlearner, F (1,33) = 6.133, p < 0.05). There was a trend toward increased input resistance between young and aged cells in the learner group (learner, F (1,30) = 3.343, p = 0.08).