UC San Diego

Motor learning is an essential aspect of an animal’s everyday behaviors. As the environment around us evolves, animals constantly learn and adapt to new motor skills in order to survive. The primary motor cortex (M1) is required for motor learning. To learn and generate voluntary movements, M1 receives long-range inputs that carry movement-related information; this information is then processed by local M1 neural network and output to downstream circuits. However, the functional roles of these long-range inputs to M1 remain unclear. Here, we investigate motor learning as mice learn a sound-cued forelimb lever-press task for two weeks. Upon inactivation of the motor thalamus with chemogenetic tools, mice’s ability to execute the learned lever-press movement become significantly impaired. Our results suggest the thalamocortical inputs as the main driver underlying movement execution at the expert stage of motor learning.