title: Parcellation of the human substantia nigra based on anatomical connectivity to the striatum.
abstract: Substantia nigra/ventral tegmental area (SN/VTA) subregions, defined by dopaminergic projections to the striatum, are differentially affected by health (e.g. normal aging) and disease (e.g. Parkinson's disease). This may have an impact on reward processing which relies on dopaminergic regions and circuits. We acquired diffusion tensor imaging (DTI) with probabilistic tractography in 30 healthy older adults to determine whether subregions of the SN/VTA could be delineated based on anatomical connectivity to the striatum. We found that a dorsomedial region of the SN/VTA preferentially connected to the ventral striatum whereas a more ventrolateral region connected to the dorsal striatum. These SN/VTA subregions could be characterised by differences in quantitative structural imaging parameters, suggesting different underlying tissue properties. We also observed that these connectivity patterns differentially mapped onto reward dependence personality trait. We show that tractography can be used to parcellate the SN/VTA into anatomically plausible and behaviourally meaningful compartments, an approach that may help future studies to provide a more fine-grained synopsis of pathological changes in the dopaminergic midbrain and their functional impact.
authors.affiliation: Institute of Cognitive Neuroscience, University College London, London WC1N 3AR, UK; Wellcome Trust Centre for Neuroimaging, University College London, London WC1N 3BG, UK. Electronic address: rumana.neuro@gmail.com.
authors.forename: Rumana
authors.initials: R
authors.lastname: Chowdhury
authors.affiliation: Wellcome Trust Centre for Neuroimaging, University College London, London WC1N 3BG, UK; Stroke and Dementia Research Centre, St. George's University of London, Cranmer Terrace, London SW17 0RE, UK.
authors.forename: Christian
authors.initials: C
authors.lastname: Lambert
authors.affiliation: Wellcome Trust Centre for Neuroimaging, University College London, London WC1N 3BG, UK.
authors.forename: Raymond J
authors.initials: RJ
authors.lastname: Dolan
authors.affiliation: Institute of Cognitive Neuroscience, University College London, London WC1N 3AR, UK; Otto-von-Guericke-University Magdeburg, Institute of Cognitive Neurology and Dementia Research, Leipziger Str. 44, 39120 Magdeburg, Germany; German Center for Neurodegenerative Diseases (DZNE), Leipziger Str. 44, 39120 Magdeburg, Germany.
authors.forename: Emrah
authors.initials: E
authors.lastname: Düzel
mesh_terms: D000368:Aged; D001931:Brain Mapping / Q000379:methods*; D003342:Corpus Striatum / Q000166:cytology* / Q000502:physiology; D056324:Diffusion Tensor Imaging; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D009434:Neural Pathways / Q000166:cytology* / Q000502:physiology; D010551:Personality / Q000502:physiology; D012201:Reward; D013378:Substantia Nigra / Q000166:cytology* / Q000502:physiology
keywords: Connectivity; Diffusion-weighted imaging; Reward; Segmentation; Substantia nigra