ABSTRACT
Objective To explore the impact and protective mechanisms of head cooling on neural activity during passive hyperthermia.Methods Sixteen subjects were randomly exposed for 1 h to three different conditions: normal (25℃), hot (50℃) and head cooling (chamber:50℃,cold packs:5℃),after environment exposure, rs-fMRI were performed.Regional homogeneity(ReHo) datum at three different conditions were analyzed by REST2.0 to obtain brain areas with statistical difference.Brain voxel with statistical difference were selected as ROIs to ReHo values and were analyzed by One-Way ANOVA with SPSS18.0.Neural activity of brain areas with statistical difference were compared in any two groups by Post hoc.Results The brain regions showing differences among three groups included right orbital frontal cortex,left middle frontal gyrus,bilateral amygdala,left middle temporal gyrus,left hippocampus,bilateral parietal inferior, left precentral gyrus.Compared with normal group, ReHo increased in right orbital frontal cortex, and decreased in left precentral gyrus,left middle frontal gyrus,left parietal inferior,but no changed in bilateral amygdala,left middle temporal gyrus,left hippocampus,right parietal inferior in head cooling group.Compared with hot group,head cooling group showed increased ReHo in left middle temporal gyrus,left hippocampus,right parietal inferior,and decreased ReHo in bilateral amygdala,left parietal inferior,unchanged ReHo in right orbital frontal cortex, left precentral gyrus, left middle frontal gyrus.Conclusion The specified alterations of ReHo may reflect that the head cooling could partially eliminate the impact of passive hyperthermia, and is closely linked with emotional function.