Figure 3.

Prevention of McN-A-343 (0.03 mg per mouse i.c.v.)-induced antinociception by pretreatment with an antisense ODN (aODN) to M₁ gene in the mouse hot-plate test. Mice were i.c.v. injected with vehicle, aODN or degenerated ODN (dODN) at the dose of 0.3 (A), 1.0 (B) and 2.0 nmol (C) per single i.c.v. injection on days 1, 4 and 7. The hot plate test was performed 24 h after the last i.c.v. injection. Vertical lines give s.e.mean. Each point represents the mean of 12–15 mice. ^*P<0.05; ^**P<0.01 in comparison with dODN+McN-A343-treated mice.