Altered Functional Connectivity Density between Obesity and Type 2 Diabetes Mellitus in Rat brain.

Motivation: Obesity and hyperglycemia would both affect brain function, while the longitudinal evolution of brain connectivity from obesity to diabetes is unknow. Goal(s): Obesity and diabetes rat brain were evaluated to find the regions that were mostly affected by the diabetic incidence. Approach: Rats were scanned at baseline and 10 days after streptozotocin injection (for diabetes model). Functional connectivity density (FCD) was applied to detect affected brain regions. Results: Visual cortex’s FCD was increased in both obesity and diabetes. Diabetic rats show increased FCD in insular cortex and decreased FCD in ventral pallidum after streptozotocin injection, and these changes are correlated with fasting glycemia. Impact: Obesity and diabetes show a progressive effect on cortex including visual and insular region. Acute changes are found in diabetic brain after streptozotocin injection for ventral pallidum, which suggested an impaired reward system in the development of T2DM.