Abnormal functional connectivity of the habenula in mild cognitive impairment patients with depression symptoms revealed by resting-state functional magnetic resonance imaging

Background: Recent research suggests that abnormalities in the habenula (HB), a core area of the brain that transmits reward information, may be a determinant of depression. However, it is not clear whether the functional connectivity (FC) pattern of the mild cognitive impairment (MCI) with and without depression symptoms is abnormal. Methods: In this study, we used resting-state functional magnetic resonance imaging (fMRI) to examine the FC pattern of the HB in MCI patients with depression symptoms (D-MCI). We acquired fMRI data from 54 subjects on a 3T MRI. Subjects collected included 16 patients with D-MCI, 18 patients with MCI with no depression, and 20 healthy controls. One way ANCOVA and post hoc t-test were used to compare the difference in FC strength between the three groups. Results: The D-MCI group had altered FC between the left HB and the right superior temporal gyrus, right inferior frontal gyrus/opercular part, and right middle frontal gyrus. The D-MCI group had increased FC between the right HB and precuneus. Conclusions: These results suggest that the dysfunction of the HB-Default model network might be involved in the neural mechanism underlying depression in MCI.