Séminaire de Nicolas Mallet (27_03_23)

Vendredi 27 janvier à 14h30, salle Gastaut, INT

“Function and dysfunction of pallido-striatal projections: A feedback loop within the loop?”

Nicolas Mallet (Université de Bordeaux)

“Function and dysfunction of pallido-striatal projections: A feedback loop within the loop?”

Abstract:

Basal-ganglia (BG) circuits form complex loops interacting with cortex, thalamus, and brainstem centers to perform action selection and movement control. In the last two decades, the role played by the external globus pallidus (GPe) in these subcortical circuits has changed drastically. Conventional ideas have viewed the GPe as a simple relay nucleus composed of only one population of cells that always project downstream to the subthalamic nucleus as part of the traditional indirect pathway. However, this vision has been challenged by our past findings describing a novel population of GPe neurons, the so-called arkypallidal neurons, that only project back to the striatum. In this presentation, I will describe how arkypallidal neurons are embedded in basal ganglia circuits describing in particular their input connectivity toward striatal and subthalamic afferences. Finally, I will argue that the pallido-striatal projections of arkypallidal neurons form an important negative feedback loop for striatal activity with key role in both function and dysfunctions.