title: Increase in glutamate/glutamine concentration in the medial prefrontal cortex during mental imagery: A combined functional mrs and fMRI study.
abstract: Recent functional magnetic resonance spectroscopy (fMRS) studies have shown changes in glutamate/glutamine (Glx) concentrations between resting-state and active-task conditions. However, the types of task used have been limited to sensory paradigms, and the regions from which Glx concentrations have been measured limited to sensory ones. This leaves open the question as to whether the same effect can be seen in higher-order brain regions during cognitive tasks. Cortical midline structures, especially the medial prefrontal cortex (MPFC), have been suggested to be involved in various such cognitive tasks. We, therefore set out to use fMRS to investigate the dynamics of Glx concentrations in the MPFC between resting-state and mental imagery task conditions. The auditory cortex was used as a control region. In addition, functional magnetic resonance imaging was used to explore task-related neural activity changes. The mental imagery task consisted of imagining swimming and was applied to a large sample of healthy participants (n = 46). The participants were all competitive swimmers, ensuring proficiency in mental-swimming. Glx concentrations in the MPFC increased during the imagery task, as compared to resting-state periods preceding and following the task. These increases mirror BOLD activity changes in the same region during the task. No changes in either Glx concentrations or BOLD activity were seen in the auditory cortex. These findings contribute to our understanding of the biochemical basis of generating or manipulating mental representations and the MPFC's role in this.
authors.affiliation: Mind, Brain Imaging and Neuroethics, Institute of Mental Health Research, University of Ottawa, Ottawa, Ontario, K1Z 7K4, Canada.
authors.forename: Zirui
authors.initials: Z
authors.lastname: Huang
authors.affiliation: Swimming Canada, Calgary, Alberta, T2P 3C5, Canada.
authors.forename: Henry Hap
authors.initials: HH
authors.lastname: Davis
authors.affiliation: Department of Radiology, West China Hospital of Sichuan University, Chengdu, 610041, People's Republic of China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Yue
authors.affiliation: Cluster of Excellence in Cognitive Sciences, Department of Sociology of Physical Activity and Health, University of Potsdam, Potsdam, 14469, Germany.
authors.forename: Christine
authors.initials: C
authors.lastname: Wiebking
authors.affiliation: Mind, Brain Imaging and Neuroethics, Institute of Mental Health Research, University of Ottawa, Ottawa, Ontario, K1Z 7K4, Canada.|Center for Cognition and Brain Disorders (CCBD), Hangzhou Normal University, Hangzhou, 310003, People's Republic of China.|Graduate Institute of Humanities in Medicine, Taipei Medical University, Taipei, 10001, Taiwan.|Brain and Consciousness Research Center, Taipei Medical University - Shuang Ho Hospital, New Taipei City, 23561, Taiwan.
authors.forename: Niall W
authors.initials: NW
authors.lastname: Duncan
authors.affiliation: Center for Cognition and Brain Disorders (CCBD), Hangzhou Normal University, Hangzhou, 310003, People's Republic of China.|Zhejiang Key Laboratory for Research in Assessment of Cognitive Impairments, Hangzhou Normal University, Hangzhou, 310015, People's Republic of China.
authors.forename: Jianfeng
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Mind, Brain Imaging and Neuroethics, Institute of Mental Health Research, University of Ottawa, Ottawa, Ontario, K1Z 7K4, Canada.
authors.forename: Nils-Frederic
authors.initials: NF
authors.lastname: Wagner
authors.affiliation: Mind, Brain Imaging and Neuroethics, Institute of Mental Health Research, University of Ottawa, Ottawa, Ontario, K1Z 7K4, Canada.
authors.forename: Annemarie
authors.initials: A
authors.lastname: Wolff
authors.affiliation: Mind, Brain Imaging and Neuroethics, Institute of Mental Health Research, University of Ottawa, Ottawa, Ontario, K1Z 7K4, Canada.|Center for Cognition and Brain Disorders (CCBD), Hangzhou Normal University, Hangzhou, 310003, People's Republic of China.|Graduate Institute of Humanities in Medicine, Taipei Medical University, Taipei, 10001, Taiwan.|Brain and Consciousness Research Center, Taipei Medical University - Shuang Ho Hospital, New Taipei City, 23561, Taiwan.|Zhejiang Key Laboratory for Research in Assessment of Cognitive Impairments, Hangzhou Normal University, Hangzhou, 310015, People's Republic of China.|Research Center for Mind, Brain and Learning, National Chengchi University, Taipei, 10001, Taiwan.|Department of Psychology, National Chengchi University, Taipei, 10001, Taiwan.
authors.forename: Georg
authors.initials: G
authors.lastname: Northoff
mesh_terms: D000293:Adolescent; D000328:Adult; D056352:Athletes; D001931:Brain Mapping; D002560:Cerebrovascular Circulation / Q000502:physiology; D005260:Female; D018698:Glutamic Acid / Q000378:metabolism*; D005973:Glutamine / Q000378:metabolism*; D006801:Humans; D007092:Imagination / Q000502:physiology*; D008279:Magnetic Resonance Imaging; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D009483:Neuropsychological Tests; D010100:Oxygen / Q000097:blood; D017397:Prefrontal Cortex / Q000502:physiology*; D013550:Swimming / Q000502:physiology*; D055815:Young Adult
chemical_list: D005973:Glutamine; D018698:Glutamic Acid; D010100:Oxygen
keywords: functional magnetic resonance imaging; glutamate; glutamine; magnetic resonance spectroscopy; medial prefrontal cortex; mental imagery