ABSTRACT
Parkinson’s disease (PD) is a neurodegenerative disorder affecting motor control. Dysfunction of motor cortices has been suggested to contribute to the motor symptoms of PD. However, little is known on the link between cortical dopaminergic loss, abnormalities in neural activity and motor deficits. We address this issue by focusing on the anterior lateral motor cortex (ALM) of mice performing a cued-licking task. We first demonstrate licking deficits and concurrent alterations of spiking activity in ALM of hemi-parkinsonian mice. Hemi-parkinsonian mice displayed delayed licking initiation, shorter duration of licking bouts, and lateral deviation of tongue protrusions. In addition, we observed a reduction in cue responsive neurons and altered preparatory activity. Acute and local blockade of D1 receptors in ALM recapitulated some of the behavioral and neural deficits observed in hemi-parkinsonian mice. Our data show a direct relationship between cortical D1 receptor modulation, cue-evoked and preparatory activity in ALM, and licking initiation.