Table 2.
Outline of experimental groups and procedures for the effect of varenicline on the expression and acquisition of ethanol-induced locomotor sensitization studies
| Experimental Groups | All mice received two injections spaced 15 min apart on all days | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Day 1–2 | Day 3 | Day 4–5 | Day 6 | Day 7–8 | Day 9 | Day 10–11 | Day 12 | Day 13 | Day 14 | |
| Effect of Varenicline on the Expression of Sensitization | ||||||||||
| SAL → VAR (4 groups: 0, 0.5, 1, and 2 mg/kg) + E2 | SAL, SAL | SAL, SAL | SAL, SAL | SAL, SAL | SAL, SAL | SAL, SAL | SAL, SAL | SAL, SAL | VAR, E2 | SAL, SAL |
| E2 → VAR (4 groups: 0, 0.5, 1, and 2 mg/kg) + E2 | SAL, SAL | SAL, E2 | SAL, E2 | SAL, E2 | SAL, E2 | SAL, E2 | SAL, E2 | SAL, E2 | VAR, E2 | SAL, SAL |
| SAL → VAR (4 groups: 0, 0.5, 1, and 2 mg/kg) + SAL | SAL, SAL | SAL, SAL | SAL, SAL | SAL, SAL | SAL, SAL | SAL, SAL | SAL, SAL | SAL, SAL | VAR, SAL | SAL, SAL |
| Effect of Varenicline on the Acquisition of Sensitization | ||||||||||
| VAR (4 groups: 0, 0.5, 1, and 2 mg/kg) + SAL → E2 | SAL, SAL | VAR, SAL | VAR, SAL | VAR, SAL | VAR, SAL | VAR, SAL | VAR, SAL | VAR, SAL | SAL, E2 | SAL, SAL |
| VAR (4 groups: 0, 0.5, 1, and 2 mg/kg) + E2 → E2 | SAL, SAL | VAR, E2 | VAR, E2 | VAR, E2 | VAR, E2 | VAR, E2 | VAR, E2 | VAR, E2 | SAL, E2 | SAL, SAL |
| Activity test | Yes | Yes | No | Yes | No | Yes | No | Yes | Yes & Blood | Yes |
Under Experimental Groups, the entry prior to the arrow indicates the repeated treatment during the acquisition phase (Day 3 – Day 12) and the entry after the arrow indicates the treatment on the ethanol challenge day (Day 13). Entries under Day 1 – Day 14 indicate the two injections received. For the expression study, the effect of varenicline was assessed on day 13 by pretreating mice with varenicline (0, 0.5, 1 or 2 mg/kg) prior to ethanol challenge or saline treatment. For the acquisition study, the effect of varenicline (0, 0.5, 1 or 2 mg/kg) was assessed by administering it before ethanol or saline during the sensitization acquisition period (Day 3 – Day 12), and then assessing the response to ethanol challenge on Day 13. In both studies, mice were tested after saline treatment on Day 14 to assess whether prior treatments affected baseline activity levels that had been assessed on Day 1 (novel apparatus) and Day 2 (familiar environment). Information given in the Activity Test row of the table applies to both studies. E2 = 2 g/kg ethanol; SAL = 0.9% saline; VAR = varenicline; Yes = activity test was performed; No = no activity test was performed; Blood = a blood sample for blood ethanol concentration determination was obtained after activity testing on this day.