Lieu : CGFB – Salle de conférence
Louise Parr-Brownlie
Départements d’anatomie, Centre de recherche sur la santé cérébrale,
Brain Research New Zealand, Université d’Otago, Dunedin
Invitée par Clémentine Bosch-Bouju – Nutrineuro
Abstract :
Parkinson’s disease is a movement disorder that affects 0.2% of people over 60 years of age. Drug treatments are effective initially but cause dyskinesias in 80% of patients. Deep brain stimulation is an adjunct treatment, but also causes side effects such as depression. Novel treatments are needed to improve the quality of life and independence for patients. To address this, we have been exploring structural and pathophysiological in the basal ganglia-thalamocortical pathway in the 6-hydroxydopamine (6-OHDA) hemi-parkinsonian lesioned model. We have found that boutons in ventroanterior (VA) motor thalamus that arose from neurons with somata in a basal ganglia output nucleus (substantia nigra pars reticulata, SNpr) were smaller and had fewer synapses in 6-OHDA lesioned compared to sham rats. Resting and movement-related activity of VA neurons were altered in parkinsonian rats. To test if VA activity controls movements, we optogenetically stimulated acute parkinsonian rats using the timing of typical VA spiking activity from sham rats and found that reaching was restored in parkinsonian rats. Our data show that motor thalamus activity controls movements. In addition, despite structural changes of basal ganglia input to motor thalamus in parkinsonian rats, stimulating VA neurons with complex patterns may treat movement deficits.