title: [Effect of subanaesthetic dose of ketamine on mechanical stimulus on brain regions].
abstract: OBJECTIVE
  To investigate the effect of subanaesthetic dose of ketamine on mechanical stimulus on brain regions.
  
  
  METHODS
  Totally 13 healthy male volunteers were enrolled in this study, in whom 0 and 100 ng/ml ketamine were administrated by target controlled infusion system in pilot study. After von Frey filaments (vFFs) 300 g were used as mechanical stimuli, Visual Analogue Scale scores were evaluated. Functional magnetic resonance imaging (fMRI)was taken 1 week after pilot study at the following sequences: structure imaging + functional imaging (stimulus sequence with 300 g vFFs, ketamine sequence); stimulus sequence = 6×(20s on + 20s off), with target concentration of ketamine at 0,100 ng/ml.fMRI result was processed by SPM2 and Metlab 7.01 software package.
  
  
  RESULTS
  Posterior cerebellum lobe and corpus callosum were inhibited at 100 ng/ml under vFFs stimulus, whereas cingulate gyrus, middle frontal gyrus, inferior parietal lobule, occipital lobe, and posterior cerebellum lobe were activated at 100 ng/ml under vFFs stimulus.
  
  
  CONCLUSIONS
  Ketamine 100 ng/ml exerts its effect on pain related brain regions. It can both activate and inhibit these brain regions, with the activating effect being the primary effect.
authors.affiliation: Department of Anesthesiology, Cancer Hospital, Beijing, China.
authors.forename: Liang
authors.initials: L
authors.lastname: Zou
authors.forename: Hai-yan
authors.initials: HY
authors.lastname: Wang
authors.forename: Hao
authors.initials: H
authors.lastname: Yuan
authors.forename: Lei
authors.initials: L
authors.lastname: Xu
authors.forename: Li
authors.initials: L
authors.lastname: Sun
authors.forename: Tie-hu
authors.initials: TH
authors.lastname: Ye
mesh_terms: D000328:Adult; D000700:Analgesics / Q000008:administration & dosage* / Q000494:pharmacology; D001921:Brain / Q000187:drug effects* / Q000503:physiopathology*; D006801:Humans; D007649:Ketamine / Q000008:administration & dosage* / Q000494:pharmacology; D008279:Magnetic Resonance Imaging; D008297:Male; D010146:Pain / Q000503:physiopathology*; D010865:Pilot Projects
chemical_list: D000700:Analgesics; D007649:Ketamine