Motor learning refines premotor cortical constraint during skilled forelimb behavior

Motor learning transforms variable actions into reliable skilled behavior, but how premotor cortex supports this transformation remains unclear. We longitudinally recorded bilateral local field potentials and single-unit activity from the rat rostral forelimb area while animals acquired a single-pellet retrieval task. Here, we show that improved skill was accompanied by reduced, rather than increased, task-related premotor recruitment. Despite this attenuation, firing remained dominated by suppression around pellet retrieval, and stronger pre-retrieval suppression was associated with greater odds of successful performance. Population neural state analysis further showed that successful actions were most strongly coupled to sustained pre-retrieval engagement early in learning, whereas later success occurred with less population-level engagement. These findings reveal premotor cortical constraint as a population-level process that is progressively refined as motor learning transforms variable actions into reliable skilled behavior.