Effect of subanaesthetic dose of ketamine on mechanical stimulus on brain regions / 中国医学科学院学报

ABSTRACT

<p><b>OBJECTIVE</b>To investigate the effect of subanaesthetic dose of ketamine on mechanical stimulus on brain regions.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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.</p><p><b>CONCLUSIONS</b>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.</p>