Mean ± S.E.M. estimates for selected measures of the circadian rhythm of responding on the active and inactive lever in rats allowed 23-h access to the highest nicotine IVSA dose
Amplitude, MESOR, peak, and nadir are expressed as responses per 3 h. Acrophase is expressed as hours following the onset of the test session, which was initiated 7 h before the onset of the dark cycle.
0.06 Dose | Amplitude | MESOR | Acrophase | Peak | Nadir | Goodness of Fit (r2) |
|---|---|---|---|---|---|---|
| Active | ||||||
| Days 1 to 5 | 1.11 ± 0.14* | 0.76 ± 0.09 | 13.1 ± 0.3 | 1.87 ± 0.23 | -0.36 ± 0.06* | 0.72 ± 0.04 |
| Days 11 to 12 | 0.94 ± 0.10 | 0.81 ± 0.07 | 13.2 ± 0.4 | 1.75 ± 0.15 | -0.12 ± 0.09 | 0.62 ± 0.04 |
| Days 14 to 15 | 0.79 ± 0.09 | 0.74 ± 0.08 | 13.4 ± 0.7 | 1.53 ± 0.14 | -0.05 ± 0.09 | 0.70 ± 0.05 |
| Days 20 to 21 | 0.78 ± 0.10 | 0.67 ± 0.07 | 12.9 ± 0.3 | 1.45 ± 0.15 | -0.10 ± 0.07 | 0.63 ± 0.05 |
| Days 36 to 40 | 0.53 ± 0.06† | 0.60 ± 0.06 | 13.2 ± 0.4 | 1.13 ± 0.12 | 0.07 ± 0.06*† | 0.61 ± 0.05 |
| Inactive | ||||||
| Days 1 to 5 | 0.55 ± 0.11 | 0.40 ± 0.07 | 13.0 ± 0.4 | 0.95 ± 0.18 | -0.15 ± 0.05 | 0.59 ± 0.05 |
| Days 36 to 40 | 0.49 ± 0.12 | 0.30 ± 0.06 | 11.9 ± 1.1 | 0.80 ± 0.18 | -0.19 ± 0.06 | 0.59 ± 0.05 |
| Overall interaction | F1,30 = 6.8; p < 0.01 | F1,30 = 0.3; p = N.S. | F1,30 = 1.0; p = N.S. | F1,30 = 3.7; p = N.S. | F1,30 = 13.4; p < 0.001 | F1,30 = 1.1; p = N.S. |
| Main effect time | F1,30 = 10.1; p < 0.003 | F1,30 = 4.6; p < 0.04 | F1,30 = 0.7; p = N.S. | F1,30 = 8.6; p < 0.01 | F1,30 = 9.5; p < 0.004 | F1,30 = 1.2; p = N.S. |
| Main effect lever | F1,30 = 6.7; p < 0.01 | F1,30 = 14.6; p < 0.001 | F1,30 = 1.0; p = N.S. | F1,30 = 10.1; p < 0.003 | F1,30 = 0.3; p = N.S. | F1,30 = 1.1; p = N.S. |