The Thalamostriatal Projections Contribute to the Initiation and Execution of a Sequence of Movements.

One of the main inputs driving striatal activity is the thalamostriatal projection. While the hypothesis postulating that the different thalamostriatal projections contribute differentially to shape the functions of the striatum is largely accepted, existing technical limitations have hampered efforts to prove it. Here, through the use of electrophysiological recordings of antidromically photo-identified thalamostriatal neurons and the optogenetic inhibition of thalamostriatal terminals, we identify that the thalamostriatal projections from the parafascicular and the ventroposterior regions of the thalamus contribute to the smooth initiation and the appropriate execution of a sequence of movements. Our results support a model in which both thalamostriatal projections have specific contributions to the initiation and execution of sequences, highlighting the specific contribution of the ventroposterior thalamostriatal connection for the repetition of actions.