Nicolas Mallet (CNRS UMR 5293, University of Bordeaux) | Dichotomous organization of the external globus pallidus: from molecules to function

Abstract

In the last two decades, conventional ideas about the role of the external globus pallidus (GPe) in the basal ganglia have changed drastically: from being a simple relay nucleus part of the indirect pathway to a central hub controlling the activity and synchrony level of basal ganglia circuits. Also, contrary to classical models that assume functional homogeneity in the GPe, recent studies have highlighted heterogeneity at the structural, neurochemical , and electrophysiological level. In the first part of the seminar, using newly developed optogenetic toolboxes in normal and parkinsonian rats, I will provide evidences, in support of a key role of GPe to regulate the firing rate and firing pattern of targets nucleus. In a second part of the seminar, I will aim to better characterize the GPe neuronal heterogeneity at different functional level from molecules to motor behavior. I will discuss GPe cell-type classification and will present data that support a dichotomous organization of GPe.