Physical Activity, Exercise Physiology, Movement
Effects of a 12-week exercise intervention on Default Mode Network connectivity in MCI and healthy elders.
Theresa J. Smith (School of Public Health (UMD) KNES Doctoral Student)
Objective: It is important to identify effective treatments to improve brain function in Mild Cognitive Impairment (MCI), an early stage of Alzheimer’s Disease (AD). Cortical regions of the brain’s Default Mode Network (DMN) are preferentially vulnerable to amyloid plaque deposition in MCI, which may hasten AD pathogenesis and disrupt functional connectivity. We investigated the effects of a 12-week treadmill walking intervention on DMN functional connectivity in MCI and healthy elders. Participants and Methods: Sixteen MCI and 16 healthy controls, ages 60-88, engaged in a supervised 12-week treadmill walking exercise intervention. Functional MRI (fMRI) was acquired at rest; functional connectivity analysis used the left precuneus as a seed. Results: A 2(Group)x2(Time) analysis revealed significant interactions (p<0.01). The MCI group showed increased connectivity in right posterior cingulate and decreased connectivity in bilateral insula, and left frontal and middle gyri. Controls demonstrated decreased connectivity in right superior frontal and angular gyri, and right posterior cingulate. At baseline, the MCI group had greater connectivity in bilateral insula, right cingulate, and left inferior parietal lobule. The only group difference post-intervention was greater connectivity in the MCI group in the left cingulate. Conclusions: These findings suggest 12-weeks of exercise resulted in DMN functional connectivity pattern changes in both groups. The fact that the MCI group connectivity patterns were more similar to the healthy controls after the exercise intervention lends support to the use of exercise as a therapeutic intervention in MCI.
Importance to public health: