Functional alteration of the cerebellum-cortical coupling in experimental Parkinson?s disease

MENARDY FABIEN; VARANI ANDRÉS P.; BOUSQUET ADELE; LENA CLÉMENT; POPA DANIELA

CEREBRAL CORTEX

OXFORD UNIV PRESS INC

Lugar: Oxford; Año: 2019

1047-3211

In Parkinson´s disease, the degeneration of the midbrain dopaminergic neurons isconsistently associated with modified metabolic activity in the cerebellum. Here we examined the functional reorganization taking place in the cerebello-cerebral circuit in an experimental model of Parkinson´s disease. Cerebellar optogenetic stimulations evoked normal movements, suggesting a normal coupling of cerebellum to the motor effectors. While firing rate in the primary motor cortex was decreased, cerebellar nuclei neurons showed increased firing rate. This increase may result from reduced inhibitory Purkinje cells inputs, since a population of slow and irregular Purkinje cells was observed in cerebellar hemispheres of lesioned animals. Moreover, cerebellar stimulations generated smaller electrocortical responses in the motor cortex suggesting a weaker cerebello cerebral coupling. Overall these results indicate the presence of functional changes in the cerebello-cerebral circuit, but their compensatory benefit is likely to be limited due to functional uncoupling between the cerebellum and cerebral cortex.