title: Glutamate concentration in the medial prefrontal cortex predicts resting-state cortical-subcortical functional connectivity in humans.
abstract: Communication between cortical and subcortical regions is integral to a wide range of psychological processes and has been implicated in a number of psychiatric conditions. Studies in animals have provided insight into the biochemical and connectivity processes underlying such communication. However, to date no experiments that link these factors in humans in vivo have been carried out. To investigate the role of glutamate in individual differences in communication between the cortex--specifically the medial prefrontal cortex (mPFC)--and subcortical regions in humans, a combination of resting-state fMRI, DTI and MRS was performed. The subcortical target regions were the nucleus accumbens (NAc), dorsomedial thalamus (DMT), and periaqueductal grey (PAG). It was found that functional connectivity between the mPFC and each of the NAc and DMT was positively correlated with mPFC glutamate concentrations, whilst functional connectivity between the mPFC and PAG was negatively correlated with glutamate concentration. The correlations involving mPFC glutamate and FC between the mPFC and each of the DMT and PAG were mirrored by correlations with structural connectivity, providing evidence that the glutamatergic relationship may, in part, be due to direct connectivity. These results are in agreement with existing results from animal studies and may have relevance for MDD and schizophrenia.
authors.affiliation: Mind, Brain Imaging and Neuroethics Research Unit, University of Ottawa Institute of Mental Health Research, Ottawa, Canada. niall.w.duncan@gmail.com
authors.forename: Niall W
authors.initials: NW
authors.lastname: Duncan
authors.forename: Christine
authors.initials: C
authors.lastname: Wiebking
authors.forename: Brice
authors.initials: B
authors.lastname: Tiret
authors.forename: Malgorzata
authors.initials: M
authors.lastname: Marjańska
authors.forename: Malgoranza
authors.initials: M
authors.lastname: Marjańska
authors.forename: Dave J
authors.initials: DJ
authors.lastname: Hayes
authors.forename: Oliver
authors.initials: O
authors.lastname: Lyttleton
authors.forename: Julien
authors.initials: J
authors.lastname: Doyon
authors.forename: Georg
authors.initials: G
authors.lastname: Northoff
mesh_terms: D000293:Adolescent; D000328:Adult; D063132:Connectome; D005260:Female; D018698:Glutamic Acid / Q000378:metabolism*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D018377:Neurotransmitter Agents / Q000378:metabolism*; D009714:Nucleus Accumbens / Q000502:physiology; D010487:Periaqueductal Gray / Q000502:physiology; D017397:Prefrontal Cortex / Q000502:physiology*; D012146:Rest / Q000502:physiology; D055815:Young Adult
chemical_list: D018377:Neurotransmitter Agents; D018698:Glutamic Acid