title: Sleep spindles are related to schizotypal personality traits and thalamic glutamine/glutamate in healthy subjects.
abstract: BACKGROUND
  Schizophrenia is a severe mental disorder affecting approximately 1% of the worldwide population. Yet, schizophrenia-like experiences (schizotypy) are very common in the healthy population, indicating a continuum between normal mental functioning and the psychosis found in schizophrenic patients. A continuum between schizotypy and schizophrenia would be supported if they share the same neurobiological origin. Two such neurobiological markers of schizophrenia are: (1) a reduction of sleep spindles (12-15 Hz oscillations during nonrapid eye movement sleep), likely reflecting deficits in thalamo-cortical circuits and (2) increased glutamine and glutamate (Glx) levels in the thalamus. Thus, this study aimed to investigate whether sleep spindles and Glx levels are related to schizotypal personality traits in healthy subjects.
  
  
  METHODS
  Twenty young male subjects underwent 2 all-night sleep electroencephalography recordings (128 electrodes). Sleep spindles were detected automatically. After those 2 nights, thalamic Glx levels were measured by magnetic resonance spectroscopy. Subjects completed a magical ideation scale to assess schizotypy.
  
  
  RESULTS
  Sleep spindle density was negatively correlated with magical ideation (r = -.64, P < .01) and thalamic Glx levels (r = -.70, P < .005). No correlation was found between Glx levels in the thalamus and magical ideation (r = .12, P > .1).
  
  
  CONCLUSIONS
  The common relationship of sleep spindle density with schizotypy and thalamic Glx levels indicates a neurobiological overlap between nonclinical schizotypy and schizophrenia. Thus, sleep spindle density and magical ideation may reflect the anatomy and efficiency of the thalamo-cortical system that shows pronounced impairment in patients with schizophrenia.
authors: Child Development Center, University Children's Hospital Zurich, Zurich, Switzerland; Neuroscience Center Zurich, University and ETH Zurich, Zurich, Switzerland;
authors: Caroline
authors: C
authors: Lustenberger
authors: Children Research Center, University Children's Hospital Zurich, Zurich, Switzerland; MR Center, University Children's Hospital Zurich, Zurich, Switzerland; Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland;
authors: Ruth L
authors: RL
authors: O'Gorman
authors: Child Development Center, University Children's Hospital Zurich, Zurich, Switzerland; Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland;
authors: Fiona
authors: F
authors: Pugin
authors: Neuroscience Center Zurich, University and ETH Zurich, Zurich, Switzerland; Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland;
authors: Laura
authors: L
authors: Tüshaus
authors: Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland; Division of Neonatology, University Hospital Zurich, Zurich, Switzerland;
authors: Flavia
authors: F
authors: Wehrle
authors: Neuroscience Center Zurich, University and ETH Zurich, Zurich, Switzerland; Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland; Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland;
authors: Peter
authors: P
authors: Achermann
authors: Child Development Center, University Children's Hospital Zurich, Zurich, Switzerland; Neuroscience Center Zurich, University and ETH Zurich, Zurich, Switzerland; Children Research Center, University Children's Hospital Zurich, Zurich, Switzerland; Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland; University Clinics for Child and Adolescent Psychiatry, Zurich, Switzerland reto.huber@kispi.uzh.ch.
authors: Reto
authors: R
authors: Huber
mesh_terms: D000328:Adult; D058256:Brain Waves / Q000502:physiology*; D018698:Glutamic Acid / Q000378:metabolism*; D005973:Glutamine / Q000378:metabolism*; D006801:Humans; D008297:Male; D012569:Schizotypal Personality Disorder / Q000503:physiopathology*; D012890:Sleep / Q000502:physiology*; D013788:Thalamus / Q000378:metabolism*; D055815:Young Adult
chemical_list: D005973:Glutamine; D018698:Glutamic Acid
keywords: continuum model; magical ideation; magnetic resonance spectroscopy; schizophrenia; sleep EEG; thalamo-cortical connections