Figure 5.

Antinociceptive effect of nicotine in the hot plate test. Latencies to show the first nocifensive sign (A and D), hindpaw licking or flinching (B and E), and jumping (C and F) were measured in male (A, B, and C) and female (D, E, and F) β4^+/+ (black bars) and β4^−/− (white bars) mice 5 min after s.c. injection of nicotine. The numbers of mice used in each group are indicated in the bars in (A) and (D). Data were subjected to repeated-measures ANOVA, followed by post-hoc comparisons (**p < .01, wild-type vs. knockout; #p < .05, ##p < .01, nicotine vs. saline, Newman–Keuls test).