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The dark side of dopamine: the paradoxical influences of dopamine on striatal motor functions| title | The dark side of dopamine: the paradoxical influences of dopamine on striatal motor functions |
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| start_date | 2024/03/29 |
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| schedule | 11h30 |
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| online | no |
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| location_info | / |
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| summary | The initial description of dopamine’s actions in the brain highlighted its importance in promoting movement and mediating pleasure and reward, but its role is much more versatile, with unexpected effects that are sometimes even opposed to these original major functions. The heterogeneity of the mesencephalic dopaminergic system is now evident, mainly characterized by the existence of multiple sub-circuits involving sub-populations of dopamine neurons targeting distinct structures to explain such contradictory influences, such as aversion, or motor inhibition, which was the focus of my work. This multi-faceted influence of dopamine is not only exerted through these parallel circuits, but also varies according to the animal’s status and context, and through complex signaling on its targets. I will present some findings revealing an antagonistic mode of action of dopamine that can restore a motor brake, upon certain conditions, involving unconventional targets in the striatum necessary for the proper control of movement.
The action of dopamine in the striatum is often postulated to promote movement through a synergistic effect on activatory D1 and inhibitory D2 receptors, so far thought to be exclusively expressed in the two classical direct and indirect pathways, respectively. One of the main findings of our studies was the identification of a third pathway, originating from « hybrid » neurons, previously described by the co-expression of D1 and D2 receptors, playing a key role in balancing the motor functions of the two main striatal pathways, and in mediating paradoxical actions of dopamine in the basal ganglia system. |
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| responsibles | Perrais, Thoumine |
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Workflow history| from state (1) | to state | comment | date |
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| submitted | published | | 2024/03/20 14:36 UTC |
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