title: Sparse pallidal connections shape synchrony in a network model of the basal ganglia.
abstract: Neural synchrony in the basal ganglia, especially in the beta frequency band (13-30 Hz), is a hallmark of Parkinson's disease and considered as antikinetic. In contrast, the healthy basal ganglia show low levels of synchrony. It is currently unknown where synchrony and oscillations arise in the parkinsonian brain and how they are transmitted through the basal ganglia, as well as what makes them dependent on dopamine. The external part of the globus pallidus has recently been identified as a hub nucleus in the basal ganglia, possessing intrinsic inhibitory connections and possibly also gap junctions. In this study, we show that in a conductance-based network model of the basal ganglia, the combination of sparse, high-conductance inhibitory synapses and sparse, low-conductance gap junctions in the external part of the globus pallidus could effectively desynchronize the whole network. However, when gap junction coupling became strong enough, the effect was impeded and activity synchronized. In particular, sustained periods of beta coherence occurred between some neuron pairs. As gap junctions can change their conductance with the dopamine level, we suggest pallidal gap junction coupling as a mechanism contributing to the development of beta synchrony in the parkinsonian basal ganglia.
authors.affiliation: Applied Analysis, MIRA Institute of Technical Medicine and Biomedical Technology, University of Twente, 7500 AE, Enschede, The Netherlands.|Biomedical Signals and and Systems, MIRA Institute of Technical Medicine and Biomedical Technology, University of Twente, Enschede, The Netherlands.
authors.forename: Bettina C
authors.initials: BC
authors.lastname: Schwab
authors.affiliation: Biomedical Signals and and Systems, MIRA Institute of Technical Medicine and Biomedical Technology, University of Twente, Enschede, The Netherlands.|Biophysics, Donders Institute for Brain, Cognition and Behavior, Radboud University, Nijmegen, The Netherlands.
authors.forename: Richard J A
authors.initials: RJA
authors.lastname: van Wezel
authors.affiliation: Applied Analysis, MIRA Institute of Technical Medicine and Biomedical Technology, University of Twente, 7500 AE, Enschede, The Netherlands.
authors.forename: Stephan A
authors.initials: SA
authors.lastname: van Gils
mesh_terms: D000465:Algorithms; D000818:Animals; D001479:Basal Ganglia / Q000502:physiology*; D001611:Beta Rhythm / Q000502:physiology; D003198:Computer Simulation; D003344:Cortical Synchronization / Q000502:physiology*; D004298:Dopamine / Q000378:metabolism; D017629:Gap Junctions / Q000378:metabolism; D006801:Humans; D008959:Models, Neurological; D009433:Neural Inhibition / Q000502:physiology; D009434:Neural Pathways / Q000502:physiology; D009474:Neurons / Q000502:physiology*; D051381:Rats; D012984:Software
chemical_list: D004298:Dopamine
keywords: beta oscillations; dopamine; gap junctions; globus pallidus; inhibition