Information transmission of the limbic system during positive emotional processing in patients with major depression disorder: a magnetic source imaging study

Abstract

Objective To investigate whether abnormal betweeness centrality of graph theory analysis during facial emotional processing exists in depression when they recognize happy face with the technology of magnetoencephalography (MEG), and discuss the possible aberrant mechanism of depression processing. Methods Thirty-four major depressive patients and 34 matched healthy volunteer controls participated in the experiment. The 0-600 ms period MEG signals of 90 brain areas from automated-anatomical labeling template were separated into sequential time intervals. Coherence method was used to identify the functional connectivity matrix. Then betweeness centrality of each node was calculated. The correlation analysis was conducted between the betweeness centrality and the severity of depressive symptoms according to HAMD17 scores. Results Compared with the controls, during 0-600 ms, depressive patients showed decreased betweeness centrality in right super frontal orbital gyrus (P=0.000 38), left middle orbital frontal gyrus (P=0.000 16), right middle orbital frontal gyrus(P=0.000 23), the right amygdala (P=0.000 43), which were corrected by false discovery rate. Among them, in the depression group, the right superior orbitofrontal cortex betweenness centrality and the total HAMD17 score (r=-0.481, P=0.004) and the anxiety/somatization factor score (r=-0.383, P=0.026) were negatively correlated, and the betweenness centrality of the right middle orbitofrontal gyrus was negatively correlated with the total HAMD17 score (r=-0.749, P<0.01) and anxiety/somatization factor score (r=-0.431, P=0.011). Conclusion The limbic system information transmission dysfunction may be the important pathological basis of depression patients with positive emotion processing abnormalities, especially in the orbital frontal gyrus and the amygdaloid nucleus. Key words: Depressive disorder; Magnetoencephalography; Amygdala; Emotional face; Betweenness centrality