title: Light-dependent alteration of serotonin-1A receptor binding in cortical and subcortical limbic regions in the human brain.
abstract: OBJECTIVE
  Climate, in particular sunshine, influences mood and energy levels, creating a positive upswing of mood on bright, sunny days and negative downswing in cold, dark winter seasons. Higher serotonin transporter availability in healthy human subjects in times of lesser light exposure and lower serotonin levels have been shown in winter.
  
  
  METHODS
  We examined the light-dependent variations in serotonin-1A receptor binding in limbic regions in 36 drug-naive healthy human subjects. Receptor binding was quantified using positron emission tomography and the radioligand [carbonyl-¹¹C]WAY-100635. Binding potential values were related to the amount of individual exposure to sunlight (daily duration of sunshine) and global radiation (total light intensity).
  
  
  RESULTS
  We found a 20-30% lower serotonin-1A receptor binding in the group exposed to a lower amount of global light radiation. Partial correlation analysis revealed significant positive correlations between the regional postsynaptic serotonin-1A receptor binding and global radiation accumulated over a period of 5 days.
  
  
  CONCLUSIONS
  Seasonal factors, such as daily amount of sunshine and global radiation, influence serotonin-1A receptor binding in limbic brain regions of healthy human subjects. Combined with recently demonstrated seasonal fluctuations in the serotonin transporter availability, our results underline the importance of seasonal factors in the regulation of the serotonergic transmission.
authors: Department of Psychiatry and Psychotherapy, Medical University of Vienna, Vienna, Austria.
authors: Christoph
authors: C
authors: Spindelegger
authors: Patrycja
authors: P
authors: Stein
authors: Wolfgang
authors: W
authors: Wadsak
authors: Martin
authors: M
authors: Fink
authors: Markus
authors: M
authors: Mitterhauser
authors: Ulrike
authors: U
authors: Moser
authors: Markus
authors: M
authors: Savli
authors: Leonhard-Key
authors: LK
authors: Mien
authors: Elena
authors: E
authors: Akimova
authors: Andreas
authors: A
authors: Hahn
authors: Matthaeus
authors: M
authors: Willeit
authors: Kurt
authors: K
authors: Kletter
authors: Siegfried
authors: S
authors: Kasper
authors: Rupert
authors: R
authors: Lanzenberger
mesh_terms: D000328:Adult; D000679:Amygdala / Q000000981:diagnostic imaging / Q000378:metabolism; D001921:Brain / Q000000981:diagnostic imaging / Q000378:metabolism*; D002250:Carbon Radioisotopes; D005260:Female; D005625:Frontal Lobe / Q000000981:diagnostic imaging / Q000378:metabolism; D006179:Gyrus Cinguli / Q000000981:diagnostic imaging / Q000378:metabolism; D006624:Hippocampus / Q000000981:diagnostic imaging / Q000378:metabolism; D006801:Humans; D008027:Light; D008032:Limbic System / Q000000981:diagnostic imaging / Q000378:metabolism*; D008297:Male; D020534:Parahippocampal Gyrus / Q000000981:diagnostic imaging / Q000378:metabolism; D017440:Photoperiod; D010879:Piperazines; D049268:Positron-Emission Tomography; D011725:Pyridines; D019275:Radiopharmaceuticals; D011903:Raphe Nuclei / Q000000981:diagnostic imaging / Q000378:metabolism; D044282:Receptor, Serotonin, 5-HT1A / Q000378:metabolism*; D012189:Retrospective Studies; D012621:Seasons; D012702:Serotonin Antagonists; D013472:Sunlight
chemical_list: D002250:Carbon Radioisotopes; D010879:Piperazines; D011725:Pyridines; D019275:Radiopharmaceuticals; D012702:Serotonin Antagonists; D044282:Receptor, Serotonin, 5-HT1A; C090413:N-(2-(4-(2-methoxyphenyl)-1-piperazinyl)ethyl)-N-(2-pyridinyl)cyclohexanecarboxamide