Fig. 1

a-b Radial-arm maze choice accuracy, entries to repeat (mean ± sem). The Genotype x Session Block (p < 0.05) prompted simple main effects tests which showed that the MTKO mice had significantly (p < 0.0005) worse performance during sessions 1–6. The Genotype x Cu interaction (p < 0.08). prompted simple main effects tests which showed that Cu50 significantly (p < 0.05) impaired choice accuracy during sessions 13–18 in WT but not MTKO mice. During sessions 1–6 the MTKO mice in the Cu0 and Cu50 treatment groups were significantly worse than the wildtype mice in the same treatment groups. Tobacco extract and nicotine effects on response latencRadial-arm maze response latency Number of rats/condition: Wildtype Cu0 males = 16, Wildtype Cu0 females = 13; Wildtype Cu10 males = 23; Wildtype Cu10 females = 13; MTKO Cu0 males = 11; MTKO Cu0 females = 19; MTKO Cu10 males = 10; MTKO Cu10 females = 15