Sex differences in interhemispheric correlation and spectral power of EEG activity.

EEG activity was recorded from left and right parietal cortex in adult male and female rats on a daily basis during 3 days. Absolute and relative power and interhemispheric correlation of the EEG activity were calculated and compared between males and females. Interhemispheric correlation of the theta rhythm was higher in males than in females. Interhemispheric asymmetry in absolute power was larger in males, who showed higher power in the right than in the left parietal for all bands except for delta. Beta2 relative power was significantly higher in females. These results indicate greater functional asymmetry and higher interhemispheric coupling of the parietal cortex in male than in female rats as assessed by cortical EEG activity.