Altered functional connectivity of the amygdala and its subregions in typhoon‐related post‐traumatic stress disorder

Abstract

Background New evidence suggests that the centromedial amygdala (CMA) and the basolateral amygdala (BLA) play different roles in threat processing. Our study aimed to investigate the effects of trauma and post‐traumatic stress disorder (PTSD) on the functional connectivity (FC) of the amygdala and its subregions. Methods Twenty‐seven patients with typhoon‐related PTSD, 33 trauma‐exposed controls (TEC), and 30 healthy controls (HC) were scanned with a 3‐Tesla magnetic resonance imaging scanner. The FCs of the BLA, the CMA, and the amygdala as a whole were examined using a seed‐based approach, and then, the analysis of variance was used to compare the groups. Results We demonstrated that the BLA had a stronger connectivity with the prefrontal cortices (PFCs) and angular gyrus in the PTSD group than in the TEC group. Additionally, compared with the PTSD and the HC groups, the TEC group exhibited decreased and increased BLA FC with the ventromedial PFC and postcentral gyrus (PoCG), respectively. Furthermore, the PTSD group showed abnormal FC between the salience network and default‐mode network, as well as the executive control network. Compared with the HC group, the TEC group and the PTSD group both showed decreased BLA FC with the superior temporal gyrus (STG). Finally, the FCs between the bilateral amygdala (as a whole) and the vmPFC, and between the BLA and the vmPFC have a negative correlation with the severity of PTSD. Conclusions Decreased BLA‐vmPFC FC and increased BLA‐PoCG FC may reflect PTSD resilience factors. Trauma leads to decreased connectivity between the BLA and the STG, which could be further aggravated by PTSD.

Functional connectivity of amygdala subregions predicts vulnerability to depression following the COVID-19 pandemic

“…Convergent studies have determined that stress exposure exerts a significant effect on amygdala function. A study about resting-state functional connectivity (rsFC) found that stress-exposed people exhibited decreased rsFC between the amygdala and the superior temporal gyrus (STG) relative to health controls (HCs) ( Liu et al., 2021 ). A research on Chinese earthquake survivors reported that the PTSD group presented increased positive rsFC between the amygdala and the medial prefrontal cortex relative to a trauma-exposed control group without PTSD ( Zhang et al., 2016 ).…”

“…The amygdala is a heterogeneous nucleus that is part of the limbic system. Previous neuroimaging studies have regarded the amygdala as a unitary structure; however, increasing evidence suggests that the subregions of the amygdala exhibit distinct structures and specialised functions ( Brown et al., 2014 ; Bzdok et al., 2013 ; Kerestes et al., 2017 ; Liu et al., 2021 ; Roy et al., 2009 ). The amygdala includes three major subregions, namely, the centromedial (CM), basolateral (BL) and superficial (SF) amygdala, which modulate different functions by extensively connecting with different cortical and subcortical regions ( Bzdok et al., 2013 ; LeDoux, 2007 ).…”

“…The SF amygdala, which is adjacent to the BL amygdala, is connected with the insula, striatum and olfactory cortical areas; it is associated with olfactory and emotional stimuli ( Bzdok et al., 2013 ; Price, 2003 ). The distinct connectivity patterns of amygdala subregions have been reported by using task-based or resting-state fMRI in patients with MDD or PTSD and healthy volunteers ( Bzdok et al., 2013 ; Liu et al., 2021 ; Roy et al., 2009 ; Tang et al., 2019 ).…”

“…RsFC is a fundamental method for aiding the understanding of brain network alterations, that is, exploring the correlations of activities amongst different brain regions in mental disorders ( Deco and Kringelbach, 2014 ). By using rsFC, a recent typhoon-related PTSD study found that the PTSD group exhibited increased rsFC between the BL amygdala and the prefrontal cortices compared with the trauma-exposed control group, and both of the groups presented reduced rsFC between the BL amygdala and the STG compared with the HC group ( Liu et al., 2021 ). However, similar to studies on vulnerability or resilience to stress ( Cisler et al., 2013 ; Kaiser et al., 2018 ; Thomason et al., 2015 ), all of these studies are cross-sectional research and failed to elucidate whether the abnormal rsFC of amygdala subregions is a risk or consequence of stress exposure due to the unpredictability of stress events.…”

Eplerian Philosophy for a New Way of Life

“…New brain science formed this philosophy by showing that major brain regions are independent and self-directed; and people can think from only one region at a time (Wang et al, 2018;Sabharwal et al, 2020;Bounoua et al, 2020;Liu et al, 2020;Zhang et al, 2018;Leech & Smallwood, 2019;Kral et al, 2019).…”