Maladaptive plasticity of serotonin axon terminals in levodopa‐induced dyskinesia

Abstract

This study provides the first evidence that L-dopa treatment induces sprouting of serotonin axon terminals, with an increased incidence of synaptic contacts, and a larger activity-dependent potentiation of dopamine release in the dopamine-denervated striatum. Treatment-induced plasticity of the serotonin innervation may therefore represent a previously unappreciated cause of altered dopamine dynamics. These results are important for understanding the mechanisms by which L-dopa pharmacotherapy predisposes to dyskinesia, and for defining biomarkers of motor complications in Parkinsons disease.