BDNF and Parkinson disease: The dopaminergic dysregulation, the higher excitability of corticostriatal synapses that correlate with increased LTP and loss of LTD [206,220,223], and higher BDNF levels found in a mouse model of DYT-TOR1A dystonia [209], indicate alterations in the direct and indirect pathway SPNs, inducing an imbalance in the opposite direction as in PD.