Thalamo-cortical (TC) pathways drive information processing in the cerebral cortex. In the primary motor cortex (M1), TC inputs into layer 1 (L1) are thought to carry basal ganglia information. However, it remains unknown how the neuronal activity of L1 TC projections in M1 is related to the execution of a voluntary movement. To address this issue, using two-photon microscopy and an adeno-associated virus that encodes GCaMP6 we visualized the neuronal activity of GCaMP6-expressing TC axons in L1 of M1 while mice performed a self-initiated lever-pull task. The activity of L1 TC axons was higher during the lever-pull period than during other periods. Next, to test functional contribution of TC axonal inputs to M1, we perturbed the activity of Channelrhodopsin-2-expressing L1 TC axons during the lever-pull task by blue-light illumination on the cortical surface of M1. We found that the task performance of mice became worse during the photostimulation period. We also found that L1 TC axons innervated the apical dendritic tufts of L5 corticospinal neurons. These results suggest that L1 TC axons send a critical signal directly to L5 corticospinal neurons to execute lever pulling. We are currently examining the temporal correlation between L1 TC axonal activity and the dendritic activity of corticospinal neurons during the lever-pull task.