Cortex-wide laminar dynamics diverge during learning

Learning to link sensory information to motor actions requires coordinated activity across the cerebral cortex, but how different cortical layers contribute to learning remains unclear. Here we show that learning engages distinct, layer-specific activity patterns across the cortex of male mice during acquisition of a whisker-based go/no-go task. Using wide-field calcium imaging of either layer 2/3 or layer 5 neurons across 25 cortical areas, we found that learning produced markedly different, and sometimes opposing, changes in activity between layers. Layer 5 exhibited widespread suppression before sensory input and enhanced activity in frontal cortex during sensorimotor transformation, whereas layer 2/3 showed learning-related enhancements in higher-order sensory areas during sensation. In contrast, both layers displayed similar learning-related enhancement in barrel cortex during whisker touch. These findings reveal complementary roles of superficial and deep cortical layers during learning and demonstrate that layer-specific cortical dynamics are a fundamental feature of sensorimotor learning.