Cerebral Gender Differences Of Fractional Amplitude Of Low-frequency Fluctuation In Adult Healthy Volunteers:A Resting-state FMRI Study

Objective We sought to use the fractional amplitude of low-frequency fluctuation(fALFF)approach as an index in the resting-state functional MRI to investigate the gender differences of spontaneous brain activity within cerebral cortex in young adult healthy volunteers,in order to explain the gender differences in the field of behavioral and cognitive domain.Methods One hundred and eight healthy volunteers(54 males,54 females),right-handed,18-36 years old,normal vision and hearing,participated in the resting-state fMRI scan.Both age and education were matched in the male and female groups.The functional data were acquired by a EPI sequence(TR 3000ms,TE 30ms,Flip Angle 90°,SL 3.0mm,spacing 0.75mm,FOV 192mm×192mm,resolution 64×64).Data were processed using the AFNI software program and its preprocessing procedure was generally divided into five steps,i.e.data format conversion,slice timing,head motion correction,normalization and smoothing.Then the fALFF in the cerebral cortex of the male and female groups were compared,with AlphaSim correction,the level of significance was thresholded at P<0.005,a minimum cluster size of 14 voxels(378mm~3)and produced a false positive discovery rate,α,of less than 5%.Results There was no statistically significant difference between the male and the female groups in age,education,vision and hearing.The male group showed higher fALFF in the left precuneus,cuneus,precentral gyrus,superior frontal gyrus,parahippocampal gyrus,and the right superior temporal gyrus,while the female group showed higher fALFF in the left middle frontal gyrus and the right inferior temporal gyrus.Conclusion Our results suggested that males and females had different spontaneous brain activity within cerebral cortex during the resting state.The findings may partly explain the gender differences in behavior and cognition domains from the view of resting state brain function.