Striatal synapses, circuits, and Parkinson's disease

- Homeostatic plasticity plays an important role in mitigating striatal pathophysiology in the early stages of PD.
- Aberrant dopamine-dependent synaptic plasticity contributes to the striatal dysfunction in both PD and LID.
- Alterations in thalamostriatal circuits contribute to striatal pathophysiology and symptoms in PD.

The striatum is a hub in the basal ganglia circuitry controlling goal directed actions and habits. The loss of its dopaminergic (DAergic) innervation in Parkinson's disease (PD) disrupts the ability of the two principal striatal projection systems to respond appropriately to cortical and thalamic signals, resulting in the hypokinetic features of the disease. New tools to study brain circuitry have led to significant advances in our understanding of striatal circuits and how they adapt in PD models. This short review summarizes some of these recent studies and the gaps that remain to be filled.