Antidepressant Effects of Electroconvulsive Therapy Correlate With Subgenual Anterior Cingulate Activity and Connectivity in Depression

Abstract

The mechanisms underlying the effects of electroconvulsive therapy (ECT) in major depressive disorder (MDD) are not fully understood. Resting-state functional magnetic resonance imaging (rs-fMRI) is a new tool to study the effects of brain stimulation interventions, particularly ECT. The authors aim to investigate the mechanisms of ECT in MDD by rs-fMRI.They used rs-fMRI to measure functional changes in the brain of first-episode, treatment-naive MDD patients (n = 23) immediately before and then following 8 ECT sessions (brief-pulse square-wave apparatus, bitemporal). They also computed voxel-wise amplitude of low-frequency fluctuation (ALFF) as a measure of regional brain activity and selected the left subgenual anterior cingulate cortex (sgACC) to evaluate functional connectivity between the sgACC and other brain regions.Increased regional brain activity measured by ALFF mainly in the left sgACC following ECT. Functional connectivity of the left sgACC increased in the ipsilateral parahippocampal gyrus, pregenual ACC, contralateral middle temporal pole, and orbitofrontal cortex. Importantly, reduction in depressive symptoms were negatively correlated with increased ALFF in the left sgACC and left hippocampus, and with distant functional connectivity between the left sgACC and contralateral middle temporal pole. That is, across subjects, as depression improved, regional brain activity in sgACC and its functional connectivity increased in the brain.Eight ECT sessions in MDD patients modulated activity in the sgACC and its networks. The antidepressant effects of ECT were negatively correlated with sgACC brain activity and connectivity. These findings suggest that sgACC-associated prefrontal-limbic structures are associated with the therapeutic effects of ECT in MDD.

Depressive symptom in the first-episode schizophrenic patients is related to the reduction of grey matter volume in the subgenual anterior cingulate cortex - a pilot study

“…Simultaneously, according to some previous studies, structural and functional alterations in the temporal lobe and sgACC overlap in patients with major depression and schizophrenia [8,9,10,37]. Our findings converged with the previous findings to support the hypothesis that the sgACC is a pathological centre in patients with MDD and the hypothesis that the sgACC is a common pathological feature in patients with schizophrenia and depression [32][33][34][35][36][37]. To some extent, our findings provide indirect evidence for the postulation that the sgACC may be one of the specific pathological features of depressive symptoms in patients with schizophrenia, although conclusive evidence supporting this postulate is lacking and requires further study for confirmation.…”

“…Many previous studies have focused on investigating the pathological features of depression and confirmed that structural and functional alterations in the sgACC are pathological features of patients with depression. Moreover, these alterations are also related to the treatment response, particularly in patients with treatment-refractory depression [32][33][34][35][36]. Simultaneously, according to some previous studies, structural and functional alterations in the temporal lobe and sgACC overlap in patients with major depression and schizophrenia [8,9,10,37].…”

Kinetic study on free lipase NS81006-catalyzed biodiesel production from soybean oil

“…In our previous study, it was found that a biodiesel yield of over 90% could be obtained with free lipase NS81006-mediated biodiesel production [10][11][12][13]. However the related mechanism still needs further investigation.…”

“…Among the various lipases, free lipase has become a promising biocatalyst for biodiesel production due to the following merits: the cost of free lipase is tens of times lower compared to immobilized lipase based on the same enzymatic activity; and the risk of using free lipase is greatly reduced; free lipase can catalyze biodiesel production in water-containing system, this is very important for non-edible oils feedstock's conversion and the reuse of free lipase can be achieved through membrane recovery [7][8][9][10][11][12]. In our previous study, it was found that a biodiesel yield of over 90% could be obtained with free lipase NS81006-mediated biodiesel production [10][11][12][13].…”

Repetitive transcranial magnetic stimulation (rTMS) of the dorsolateral prefrontal cortex reduces resting-state insula activity and modulates functional connectivity of the orbitofrontal cortex in cigarette smokers

“…The local spontaneous low frequency oscillations (LFO) are associated with local neuronal activation in brain disorders (Scholvinck et al, 2010) (Jiang et al, 2011; Liu et al, 2006; Zang et al, 2007). Recently, clinical treatment studies demonstrated that the accurate localization of abnormal spontaneous brain activity was crucial for the therapeutic effects of drugs in specific diseases, e.g., depression and schizophrenia (Fryer et al, 2015; Liu et al, 2015). As an advance ALFF method, fractional ALFF (fALFF) has also been utilized in resting-state fMRI research (Zou et al, 2008).…”