title: Cortico-subthalamic inputs from the motor, limbic, and associative areas in normal and dopamine-depleted rats are not fully segregated.
abstract: The subthalamic nucleus (STN) receives monosynaptic glutamatergic afferents from different areas of the cortex, known as the "hyperdirect" pathway. The STN has been divided into three distinct subdivisions, motor, limbic, and associative parts in line with the concept of parallel information processing. The extent to which the parallel information processing coming from distinct cortical areas overlaps in the different territories of the STN is still a matter of debate and the proposed role of dopaminergic neurons in maintaining the coherence of responses to cortical inputs in each territory is not documented. Using extracellular electrophysiological approaches, we investigated to what degree the motor and non-motor regions in the STN are segregated in control and dopamine (DA) depleted rats. We performed electrical stimulation of different cortical areas and recorded STN neuronal responses. We showed that motor and non-motor cortico-subthalamic pathways are not fully segregated, but partially integrated in the rat. This integration was mostly present through the indirect pathway. The spatial distribution and response latencies were the same in sham and 6-hydroxydopamine lesioned animals. The inhibitory phase was, however, less apparent in the lesioned animals. In conclusion, this study provides the first evidence that motor and non-motor cortico-subthalamic pathways in the rat are not fully segregated, but partially integrated. This integration was mostly present through the indirect pathway. We also show that the inhibitory phase induced by GABAergic inputs from the external segment of the globus pallidus is reduced in the DA-depleted animals.
authors.affiliation: Univ. de Bordeaux, Institut des Maladies Neurodégénératives, UMR 5293, 146, Rue Léo-Saignat, 33000, Bordeaux Cedex, France.|CNRS, Institut des Maladies Neurodégénératives, UMR 5293, 33000, Bordeaux, France.|School for Mental Health and Neuroscience, Maastricht University, Maastricht, The Netherlands.|Department of Neurology, Maastricht University Medical Center, 6202 AZ, Maastricht, The Netherlands.
authors.forename: Marcus L F
authors.initials: MLF
authors.lastname: Janssen
authors.affiliation: School for Mental Health and Neuroscience, Maastricht University, Maastricht, The Netherlands.|Department of Neurosurgery, Maastricht University Medical Center, 6202 AZ, Maastricht, The Netherlands.
authors.forename: Yasin
authors.initials: Y
authors.lastname: Temel
authors.affiliation: Univ. de Bordeaux, Institut des Maladies Neurodégénératives, UMR 5293, 146, Rue Léo-Saignat, 33000, Bordeaux Cedex, France.|CNRS, Institut des Maladies Neurodégénératives, UMR 5293, 33000, Bordeaux, France.
authors.forename: Claire
authors.initials: C
authors.lastname: Delaville
authors.affiliation: MIRA Institute for Biomedical Technology and Technical Medicine, Department of Electrical Engineering, Mathematics and Computer Science, Biomedical Signals and Systems group, Twente University, 7500 AE, Enschede, The Netherlands.
authors.forename: Daphne G M
authors.initials: DGM
authors.lastname: Zwartjes
authors.affiliation: MIRA Institute for Biomedical Technology and Technical Medicine, Department of Electrical Engineering, Mathematics and Computer Science, Biomedical Signals and Systems group, Twente University, 7500 AE, Enschede, The Netherlands.
authors.forename: Tjitske
authors.initials: T
authors.lastname: Heida
authors.affiliation: Univ. de Bordeaux, Institut des Maladies Neurodégénératives, UMR 5293, 146, Rue Léo-Saignat, 33000, Bordeaux Cedex, France.|CNRS, Institut des Maladies Neurodégénératives, UMR 5293, 33000, Bordeaux, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: De Deurwaerdère
authors.affiliation: Department of Stereotactic and Functional Neurosurgery, University of Cologne, Cologne, Germany.
authors.forename: Veerle
authors.initials: V
authors.lastname: Visser-Vandewalle
authors.affiliation: Univ. de Bordeaux, Institut des Maladies Neurodégénératives, UMR 5293, 146, Rue Léo-Saignat, 33000, Bordeaux Cedex, France. abdelhamid.benazzouz@u-bordeaux.fr.|CNRS, Institut des Maladies Neurodégénératives, UMR 5293, 33000, Bordeaux, France. abdelhamid.benazzouz@u-bordeaux.fr.
authors.forename: Abdelhamid
authors.initials: A
authors.lastname: Benazzouz
mesh_terms: D000818:Animals; D004298:Dopamine / Q000172:deficiency*; D059290:Dopaminergic Neurons / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D004558:Electric Stimulation; D019054:Evoked Potentials, Motor; D059330:GABAergic Neurons / Q000378:metabolism; D005917:Globus Pallidus / Q000378:metabolism; D008032:Limbic System / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D008297:Male; D009044:Motor Cortex / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D009433:Neural Inhibition; D009434:Neural Pathways / Q000378:metabolism; D016627:Oxidopamine / Q000494:pharmacology; D017207:Rats, Sprague-Dawley; D011930:Reaction Time; D020531:Subthalamic Nucleus / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D013997:Time Factors; D005680:gamma-Aminobutyric Acid / Q000378:metabolism
chemical_list: D005680:gamma-Aminobutyric Acid; D016627:Oxidopamine; D004298:Dopamine
keywords: Associative and limbic cortices; Cortico-subthalamic hyperdirect pathway; Motor cortex; Parkinson’s disease; Subthalamic nucleus