{"id":841,"date":"2025-05-22T11:53:03","date_gmt":"2025-05-22T09:53:03","guid":{"rendered":"https:\/\/imn-prod.onlinecreation.pro\/?post_type=buni_events&p=841"},"modified":"2025-05-22T11:53:04","modified_gmt":"2025-05-22T09:53:04","slug":"soutenance-dhdr-nicolas-mallet","status":"publish","type":"buni_events","link":"https:\/\/imn.u-bordeaux.fr\/fr\/events\/soutenance-dhdr-nicolas-mallet\/","title":{"rendered":"Soutenance d’HDR – Nicolas Mallet"},"content":{"rendered":"

\"\"Lieu : centre Broca<\/strong><\/p>\n

\n

Title<\/h3>\n

Network dynamics of Basal Ganglia circuits in function and dysfunction<\/p>\n

Abstract<\/h3>\n

This \u2018Habilitation \u00e0 Diriger des Recherches\u2019<\/em> (HDR) presents an overview of my contributions to advancing our understanding of the network dynamics in basal ganglia (BG) circuits and their essential role in both normal motor functions and pathological conditions, such as those observed in Parkinson’s disease (PD) or levodopa-induced dyskinesias (LIDs). Through an integrated approach combining in vivo<\/em> electrophysiology, cell-type specific optogenetic manipulations, and fine motor behavioral testing in rodent models, my research has elucidated key neuronal mechanisms that underlie both BG function and dysfunction. Specifically, my past work has revealed the key role of the external globus pallidus (GP) in orchestrating abnormal synchronized beta oscillations in PD, highlighted the critical influence of Arky-GP neurons in action inhibition, and identified novel principle of functional connectivity that govern BG network dynamics. Together, these findings support a refined view of BG circuit organization, where cellular diversity is intrinsically linked to behavioural specialization, whether in the execution or suppression of goal-directed actions.<\/p>\n

This HDR also details how my earlier research has progressed into two major ongoing projects: the MOTOR-Code project, which further investigates the cellular and network mechanisms driving beta oscillation generation and their impact on motor function; and the MOTOR-Gate project, which explores the causal involvement of Arky-GP neurons in both normal or abnormal (i.e. LIDs) movement generation. Together, these projects enhance our understanding of the anatomo-functional organization of basal ganglia circuits, particularly their role in motor control, with the potential to inform future therapeutic strategies for motor disorders like Parkinson\u2019s disease and LIDs.<\/p>\n

\u00a0Key words
\n<\/strong><\/h3>\n

Basal Ganglia, Motor control, Parkinson\u2019s disease, Levodopa-induced dyskinesias, Normal and Abnormal Network Dynamics<\/p>\n

Selected publications<\/h3>\n

Guilhemsang L, Mallet NP (2024) <\/em>Arky-GP neurons in basal ganglia circuits: Unveiling novel pallidostriatal loops. Current Opinion in Neurobiology <\/em>Nov 27:84:102814.<\/p>\n

Aristieta A, Barresi M, Lindi S, Barriere G, Courtand G, de la Crompe\u00a0B, Guilhemsang L, Gauthier L, Fioramonti S, Baufreton J, Mallet NP. (2021<\/em>) A disynaptic circuit in the globus pallidus controls locomotion inhibition.<\/a> Current Biology<\/em>, 22;31(4):707-721.e7.<\/p>\n

de la Crompe\u00a0B, Aristieta A, Leblois A, Elsherbiny S, Boraud T, Mallet NP. (2020<\/em>) The globus pallidus orchestrates abnormal network dynamics in a model of Parkinsonism.<\/a> Nature Communications<\/em> 26;11(1):1570.<\/p>\n

Mallet N, Schmidt R, Leventhal D, Chen F, Amer N, Boraud T, and Berke JD (2016<\/em>) Arky-GP cells send a stop signal to striatum. Neuron <\/em>(89:308-316).<\/p>\n

Mallet N, Micklem BR, Henny P, Brown MT, Williams C, Bolam JP, Nakamura KC, Magill PJ (2012<\/em>) Dichotomous organization of the external globus pallidus. Neuron 21:1075-86.<\/p>\n

Jury<\/h3>\n
Pr\u00e9sident: Dr. Fran\u00e7ois Georges<\/div>\n
Rapporteur: Dr. Pierre-Olivier Fernagut<\/div>\n
Rapporteur: Dr. St\u00e9phanie Caill\u00e9-Garnier<\/div>\n
Rapporteur: Dr. Lionel Dahan<\/div>\n
Examinateur: Dr. Marianne Amalric<\/div>\n","protected":false},"excerpt":{"rendered":"

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