The Influence of Apolipoprotein E Epsilon4 Polymorphism on qEEG Profiles in Healthy Young Females: A Resting EEG Study

The epsilon4 allele of the Apolipoprotein E (ApoE) gene has been linked to various neurological conditions and the aging process in the elderly. However, evidence has suggested that the influence of ApoE epsilon4 may commence in early life. This study examined the modulatory effects of ApoE epsilon4 on regional neural activity as well as inter-regional neural interactions in a young population aged 19–21. Blood samples and resting state eyes-closed EEG signals were collected from 265 healthy females, and stratified into two groups: epsilon4 carriers and non-carriers. The values of the log-transformed mean power of 18 electrodes and the mutual information of 20 channel pairs across delta, theta, alpha and beta frequencies were analyzed. Our connectivity analysis was based on information theory, which combined Morlet wavelet transform and mutual information calculation. Between-group statistics were performed by independent t-test. We notice a consistent trend across the brain, in which ApoE epsilon4 carriers possess lower regional power at the alpha band. The epsilon4 allele is also associated with lower regional power at the theta frequency in the left frontal and posterior brain regions. Functional connectivity analyses reveal a right-lateralized network that differentiates epsilon4 carriers and non-carriers, with lower connectivity strengths for the former. Our tonic EEG analyses complement those of previous reports in that the ApoE epsilon4 allele has a negative impact on regional neural synchronization and inter-regional neural interaction.