The most optimal effective connections of prefrontal-amygdala during major depressive patients recognizing happy face / 中华行为医学与脑科学杂志

ABSTRACT

Objective To investigate whether there is exists optimal effective connections of prefrontal-amygdala in patients with major depressive disorder when they recognize dynamic positive face expressions with the technology of magnetoencephalograph (MEG),and discuss the possible aberrant mechanism of emotion processing.Methods Twenty major depressive patients and 20 well-matched healthy volunteer controls participated in the experiment.The regions of interested brain area included the primary visual cortex (V1),the precuneus (PQ),the dorsolateral prefrontal cortex (DLPFC),the anterior cingulate cortex (ACC),the amygdala (AMYG).After constructing three putative models,dynamic causal model was used to select an optimal model,then extracted all the effective connection parameters and conducted t-test under the overall optimal model between-group comparison.Results The bayesian model selection (BMS) indicated that model with top-down modulate connections between DLPFC-ACC,DLPFC-AMYG and ACC-AMYG was the most superior model,whose exceedance probability was 0.41.In the fight hemisphere of patient group,the endogenous connectivity from AMYG to ACC significantly decreased compared to healthy controls (t=-2.21,P=0.033),while the endogenous connectivity from ACC to DLPFC was enhanced significandy (t=2.50,P=0.017),which was the same with the endogenous connectivity from AMYG to DLPFC (t=2.10,P=0.040).Conclusion The effective connections of prefrontal-amygdala in major depressive disorder are exactly impaired,which may indicate that major depressive disorder have a bias toward negative.While depressed patients don' t show abnormality in the modulate connectivity under happy stimulus.