title: In-vivo Dynamics of the Human Hippocampus across the Menstrual Cycle.
abstract: Sex hormones fluctuate during the menstrual cycle. Evidence from animal studies suggests similar subtle fluctuations in hippocampal structure, predominantly linked to estrogen. Hippocampal abnormalities have been observed in several neuropsychiatric pathologies with prominent sexual dimorphism. Yet, the potential impact of subtle sex-hormonal fluctuations on human hippocampal structure in health is unclear. We tested the feasibility of longitudinal neuroimaging in conjunction with rigorous menstrual cycle monitoring to evaluate potential changes in hippocampal microstructure associated with physiological sex-hormonal changes. Thirty longitudinal diffusion weighted imaging scans of a single healthy female subject were acquired across two full menstrual cycles. We calculated hippocampal fractional anisotropy (FA), a measure sensitive to changes in microstructural integrity, and investigated potential correlations with estrogen. We observed a significant positive correlation between FA values and estrogen in the hippocampus bilaterally, revealing a peak in FA closely paralleling ovulation. This exploratory, single-subject study demonstrates the feasibility of a longitudinal DWI scanning protocol across the menstrual cycle and is the first to link subtle endogenous hormonal fluctuations to changes in FA in vivo. In light of recent attempts to neurally phenotype single humans, our findings highlight menstrual cycle monitoring in parallel with highly sampled individual neuroimaging data to address fundamental questions about the dynamics of plasticity in the adult brain.
authors.affiliation: Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany.
authors.forename: Claudia
authors.initials: C
authors.lastname: Barth
authors.affiliation: Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany.|Cerebral Imaging Centre, Douglas Mental Health Institute, Department of Psychiatry, McGill University, Montreal, Canada.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Steele
authors.affiliation: Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany.
authors.forename: Karsten
authors.initials: K
authors.lastname: Mueller
authors.affiliation: CAMH Research Imaging Centre and Campbell Family Mental Health Research Institute at the Centre for Addiction and Mental Health and the Department of Psychiatry, University of Toronto, Toronto, Canada.
authors.forename: Vivien P
authors.initials: VP
authors.lastname: Rekkas
authors.affiliation: Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany.|Clinic of Cognitive Neurology, University of Leipzig, Leipzig, Germany.|Leipzig Research Center for Civilization Diseases, University of Leipzig, Germany.
authors.forename: Katrin
authors.initials: K
authors.lastname: Arélin
authors.affiliation: Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany.
authors.forename: Andre
authors.initials: A
authors.lastname: Pampel
authors.affiliation: Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany.
authors.forename: Inga
authors.initials: I
authors.lastname: Burmann
authors.affiliation: Institute for Laboratory Medicine, Clinical Chemistry and Molecular Diagnostics, University Hospital Leipzig, Leipzig, Germany.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Kratzsch
authors.affiliation: Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany.|Clinic of Cognitive Neurology, University of Leipzig, Leipzig, Germany.|Leipzig Research Center for Civilization Diseases, University of Leipzig, Germany.|Integrated Research and Treatment Center Adiposity Diseases, University of Leipzig, Germany.|Berlin School of Mind and Brain, Mind and Brain Institute, Berlin, Germany.
authors.forename: Arno
authors.initials: A
authors.lastname: Villringer
authors.affiliation: Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany.|Clinic of Cognitive Neurology, University of Leipzig, Leipzig, Germany.
authors.forename: Julia
authors.initials: J
authors.lastname: Sacher
mesh_terms: D000328:Adult; D016880:Anisotropy; D001921:Brain / Q000502:physiology; D001931:Brain Mapping; D038524:Diffusion Magnetic Resonance Imaging; D056324:Diffusion Tensor Imaging; D004967:Estrogens / Q000502:physiology; D005260:Female; D012739:Gonadal Steroid Hormones / Q000502:physiology; D006624:Hippocampus / Q000502:physiology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging; D008597:Menstrual Cycle / Q000502:physiology*; D010060:Ovulation / Q000502:physiology; D010641:Phenotype; D012727:Sex Characteristics
chemical_list: D004967:Estrogens; D012739:Gonadal Steroid Hormones