Thesis Defense by Maya Williams 16/12/2024

Monday 16 December 2024 at 1 PM, Salle de thèse n°1(bâtiment de médecine)

Maya Williams (CoPhyBaG team)

Study of the network involving the subthalamic nucleus in different measures of motivation in rats

Jury:
Asa MACKENZIE Rapporteuse : Lund University, Lund, SUÈDE
Véronique COIZET Rapporteuse : INSERM, Université Grenoble Alpes, La Tronche, FRANCE
Florence VORSPAN Examinatrice : Assistance Publique-Hôpitaux de Paris , PARIS
Stéphanie DAUMAS Présidente du jury : CNRS, Sorbonne Université, PARIS
Christelle BAUNEZ Co-Directrice de thèse : CNRS, Aix-Marseille Université
Mickaël DEGOULET Co-Directeur de thèse : CNRS, Aix Marseille Université

Abstract: The subthalamic nucleus (STN) has long been considered a motor brain structure and is the target for Deep Brain Stimulation (DBS) treatment of Parkinson’s Disease. However, work in rats has identified the STN as a target for reducing motivation for cocaine while increasing it for sucrose. STN DBS also curbs behaviors mimicking addiction, like compulsive drug seeking and loss of control over consumption. The contribution of STN and its network in reward processes remains to be elucidated. In this thesis, we showed that high-frequency DBS and STN inhibition can induce self-stimulation in rats, highlighting the role of STN in reward processing. Using calcium imaging and optogenetic inhibition of the various hyperdirect pathways linking the prefrontal cortex to the STN, we showed their involvement in reward-seeking behavior.