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Purpose: Gamma-aminobutyric acid(GABA)is the primary inhibitory neurotransmitter in the brain,and is involved in modulating intrinsic neural activity.Previous one study has shown that GABA levels are positively correlated with resting-state amplitude of low frequency fluctuations(ALFF)in the occipital cortex in healthy volunteers [1].However,it is currently unclear if the correlations between GABA levels and ALFF can be generalized in other region,such as auditory cortex,in health volunteers.Moreover,to date there has been a paucity of studies exploring the relationship between GABA levels and topological properties of brain functional networks.In this study,therefore,we combined J-difference edited magnetic resonance spectroscopy(MRS)with resting-state functional magnetic resonance imaging(rs-fMRI)to investigate the relationship between GABA levels and intrinsic neural activity in the auditory cortex of healthy controls.Methods: Thirteen healthy controls(5 males/8 females,mean age 62.2 ± 1.9 years)were recruited in this study.All experiments were performed on a 3T scanner(Philips Achieva TX,Best,The Netherlands)equipped with a 8-channel head coil.The MEGAPRESS sequence was used to measure GABA levels in 4 x 3 x 3 cm3 volumes centered on the left and right Heschls gyri(HG).The MEGA-PRESS data were analyzed using Gannet(GABA-MRS Analysis Tool)in Matlab with Gaussian curve fitting to the GABA peaks [2].ALFF was analyzed within the MRS voxel and represented on the z-scale.The rs-fMRI data was analyzed with SPM and REST in Matlab.Anatomical Automatic Labeling(AAL)time courses were extracted from 90 regions and then the matrices of inter-parcel correlation coefficients(r)were calculated.Clustering coefficient,local efficiency and strength in the left and right HG were obtained from the “r” matrices.Results: Significant negative correlations were observed between GABA levels and clustering coefficient in the right HG(r =0.65,p =0.016); significant negative correlations were observed between GABA levels and local efficiency in the right HG(r =0.65,p =0.017); significant negative correlations were observed between GABA levels and strength in the right HG(r =0.68,p =0.010)(Fig.1); A trend toward a similar correlation was found between GABA levels and ALFF in the right MRS voxel(r =0.52,p = 0.07).Conclusion: In our study,no correlations between GABA levels and ALFF were found in the right MRS voxel in healthy controls.Therefore,the correlation between GABA levels and ALFF,as seen in the previous study,may be region-specific.This study revealed correlations between GABA levels and network parameters in the right HG in healthy volunteers.It is believed that our findings could be important for exploring associations of regional GABA with intrinsic neural activity.