Extended Data Figure 2: Motor cortex is required for the lever-press task.

a, Aspiration lesion of motor cortex impairs learning. Mice were allowed to recover for 14 days after lesion before training. Left: histological image showing lesion in the right motor cortex and quantification of lesion extents in four mice shown as a density map of the fraction of animals in which the area was lesioned. Anterior is to the top; lateral to the right. + denotes bregma. The white circle indicates the imaged area. Middle: average time from movement onset to reward throughout learning. This time is longer in mice with motor cortex lesion (P < 0.01, two-way ANOVA), indicating that the mice with a lesion are less efficient in their movements. Right: correlation of lever movements in all pairs of trials within each session throughout learning. This correlation is lower in the mice with a lesion (P < 0.001, two-way ANOVA), indicating that the mice with a lesion do not develop reproducible movements. b, Injections of muscimol, a GABA receptor agonist, into the imaged area acutely impairs performance (control versus muscimol in motor cortex, **P < 0.01, Wilcoxon rank sum test). Muscimol injections in the barrel cortex had no significant effect (control versus muscimol in barrel cortex, P = 0.35, Wilcoxon rank sum test). Control, n = 18 sessions in 6 mice; barrel cortex, n = 6 sessions in 6 mice; motor cortex, n = 6 sessions in 6 mice. c, The imaged cortical area was acutely inactivated by stimulation of ChR2 in parvalbumin-expressing inhibitory neurons by blue light in interleaved 20% of trials (n = 10 sessions in 2 animals). This optogenetic inactivation of the imaged area impaired performance on a trial-by-trial basis (***P < 0.001, Wilcoxon rank sum test). Blue light had no effect on behaviour when the window was covered with opaque silicone (n = 4 sessions in 2 animals). All error bars are s.e.m.