| Autor: |
Ryczko D; Groupe de Recherche sur le Système Nerveux Central, Département de Neurosciences, Université de Montréal, Montreal, QC, Canada H3C 3J7;, Cone JJ; Department of Psychology, University of Illinois, Chicago, IL 60607;, Alpert MH; Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL 60607;, Goetz L; Department of Psychiatry and Neuroscience, Faculty of Medicine, Centre de Recherche de l'Institut Universitaire en Santé Mentale de Québec, Université Laval, Quebec, QC, Canada G1J 2G3;, Auclair F; Groupe de Recherche sur le Système Nerveux Central, Département de Neurosciences, Université de Montréal, Montreal, QC, Canada H3C 3J7;, Dubé C; Groupe de Recherche sur le Système Nerveux Central, Département de Neurosciences, Université de Montréal, Montreal, QC, Canada H3C 3J7;, Parent M; Department of Psychiatry and Neuroscience, Faculty of Medicine, Centre de Recherche de l'Institut Universitaire en Santé Mentale de Québec, Université Laval, Quebec, QC, Canada G1J 2G3;, Roitman MF; Department of Psychology, University of Illinois, Chicago, IL 60607;, Alford S; Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL 60607;, Dubuc R; Groupe de Recherche sur le Système Nerveux Central, Département de Neurosciences, Université de Montréal, Montreal, QC, Canada H3C 3J7; Département des Sciences de l'Activité Physique, Université du Québec à Montréal, Montreal, QC, Canada H3C 3P8 rejean.dubuc@gmail.com. |
| Abstrakt: |
Dopamine neurons are classically known to modulate locomotion indirectly through ascending projections to the basal ganglia that project down to brainstem locomotor networks. Their loss in Parkinson's disease is devastating. In lampreys, we recently showed that brainstem networks also receive direct descending dopaminergic inputs that potentiate locomotor output. Here, we provide evidence that this descending dopaminergic pathway is conserved to higher vertebrates, including mammals. In salamanders, dopamine neurons projecting to the striatum or brainstem locomotor networks were partly intermingled. Stimulation of the dopaminergic region evoked dopamine release in brainstem locomotor networks and concurrent reticulospinal activity. In rats, some dopamine neurons projecting to the striatum also innervated the pedunculopontine nucleus, a known locomotor center, and stimulation of the dopaminergic region evoked pedunculopontine dopamine release in vivo. Finally, we found dopaminergic fibers in the human pedunculopontine nucleus. The conservation of a descending dopaminergic pathway across vertebrates warrants re-evaluating dopamine's role in locomotion. |
