Arkypallidal neurons in basal ganglia circuits: Unveiling novel pallidostriatal loops?

Curr Opin Neurobiol. 2023 Nov 27;84:102814. doi: 10.1016/j.conb.2023.102814. Online ahead of print.ABSTRACTJust over a decade ago, a novel GABAergic input originating from a subpopulation of external globus pallidus neurons known as Arkypallidal and projecting exclusively to the striatum was unveiled. At the single-cell level, these pallidostriatal Arkypallidal projections represent one of the largest extrinsic sources of GABA known to innervate the dorsal striatum. This discovery has sparked new questions regarding their role in striatal information processing, the circuit that recruit these neurons, and their influence on behaviour, especially in the context of action selection vs. inhibition. In this review, we will present the different anatomo-functional organization of Arkypallidal neurons as compared to classic Prototypic neurons, including their unique molecular properties and what is known about their specific input/output synaptic organization. We will further describe recent findings that demonstrate one mode of action of Arkypallidal neurons, which is to convey feedback inhibition to the striatum, and how this mechanism is differentially modulated by both striatal projection pathways. Lastly, we will delve into speculations on their mechanistic contribution to striatal action execution or inhibition.PMID:38016260 | DOI:10.1016/j.conb.2023.102814

Source: Current Opinion in Neurobiology - November 28, 2023 Category: Neurology Authors: Lise Guilhemsang Nicolas P Mallet Source Type: research