L-DOPA–induced dyskinesia in Parkinson’s
Might be caused by a loss in normal synaptic plasticity
The team leaded by Paolo Calabresi at University of Rome Tor Vergata has studied alterations of corticostriatal responses in L-DOPA treated rats (B. Picconi et al. Loss of bi-directional striatal synaptic plasticity in L-DOPA-induced dyskinesia. Nature Neuroscience, published online, doi: 10.1038/nn1040, 2003) concluding that development of dyskinesia was related to alterations in synaptic functioning of the system. In particular they noted a compromission of depotentiation depending on low-frequency stimulation which needs protein phosphatase activity: the striata of dyskinetic rats contained abnormally high levels of phospho[Thr34]-DARPP-32, an inhibitor of protein phosphatase1.
BML- April 2003