The Method Based on Functional Connectivity for the Analysis of Age Effects on Hippocampus

The study the age-related changes of hippocampus is an important issue in neuroscience. Here, we established the methodology of analyzing ¹⁸F-FDG brain PET images based on functional connectivity, and studied the age-related changes of functional networks in hippocampus detected by this method. 195 healthy volunteers were divided into 4 groups by age and were scanned in a resting state. The functional connectivity between hippocampus and other cortical and subcortical regions was estimated by the correlation analysis, and thresholded to construct functional connectivity network of hippocampus. The effect of age did interact with the connectivity pairs in functional networks of hippocampus. The connectivity rates of left hippocampus (CR_L) of 4 groups were 12%, 11%, 9% and 8%, respectively; the correlation coefficients between CRL and age was -0.9726; the connectivity rates of the whole hippocampus (CR_A) were 16%, 11%, 10% and 10%, respectively; the correlation coefficients between CRA and age was -0.8157. Analyzing PET images by functional connectivity is feasible. The functional connectivity ability of hippocampus decreased with the increase of the age, which was consistent with the physiological change of the hippocampus.