Motor skill acquisition is known to induce microstructural changes in the motor cortex grey matter, which yield the encoding of new motor memories. Whether such alterations can be measured with diffusion magnetic resonance imaging (dMRI) is still an open question. Here, diffusion kurtosis tensor imaging is used to detect specific layer changes ex-vivo in mice after learning a new lateralized motor prehension task. Mean Kurtosis (MK) was found to increase with learning in M1 layers 5b and 6. Such changes were not observed in non-task-related regions. Moreover, single subject MK distributions appear to correspond with behaviour performance.