An exploratory study of resting-state functional connectivity of amygdala subregions in posttraumatic stress disorder following trauma in adulthood

Abstract

We carried out an exploratory study aimed at identifying differences in resting-state functional connectivity for the amygdala and its subregions, right and left basolateral, centromedial and superficial nuclei, in patients with Posttraumatic Stress Disorder (PTSD), relative to controls. The study included 10 participants with PTSD following trauma in adulthood (9 females), and 10 controls (9 females). The results suggest PTSD was associated with a decreased (negative) functional connectivity between the superficial amygdala and posterior brain regions relative to controls. The differences were observed between right superficial amygdala and right fusiform gyrus, and between left superficial amygdala and left lingual and left middle occipital gyri. The results suggest that among PTSD patients, the worse the PTSD symptoms, the lower the connectivity. The results corroborate the fMRI literature that shows PTSD is associated with weaker amygdala functional connectivity with areas of the brain involved in sensory and perceptual processes. The results also suggest that though the patients traumatic experience occured in adulthood, the presence of early traumatic experiences were associated with negative connectivity between the centromedial amygdala and sensory and perceptual regions. We argue that the understanding of the mechanisms of PTSD symptoms, its behaviors and the effects on quality of life of patients may benefit from the investigation of brain function that underpins sensory and perceptual symptoms associated with the disorder.

Inhibition of Protein Synthesis Attenuates Formation of Traumatic Memory and Normalizes Fear-induced c-Fos Expression in a Mouse Model of Posttraumatic Stress Disorder

“…Lastly, our examination of c-Fos expression patterns revealed significant activation of specific brain regions during the development of PTSD-like behavior, including the prefrontal cortex (PrL, IL, Cg), amygdala (BLA) and PV. This activation pattern is consistent with data on the involvement of these regions in PTSD in humans and animals [42– 45]. The high BLA activity in PTSD aligns with extensive evidence linking amygdala functioning to PTSD symptoms in both humans [46–48] and animals [49,50].…”

Altered regional homogeneity and functional connectivity of brain activity in young HIV-infected patients with asymptomatic neurocognitive impairment

“…L. The lingual gyrus is a brain structure involved in visual processing, especially related to letters ( 35 ). It is also considered to play a role in the logical analysis and encoding of visual memory ( 36 ). Decreased ReHo in the right lingual gyrus indicates alterations in logical analysis and visual processes in young HIV-infected adults.…”

“…This result suggests that cooperation within the visual network in patients with ANI is undergoing profound changes. The visual network is mainly responsible for controlling vision and visual information processing ( 36 , 41 ). It comprises multiple adjacent functional areas that work synergistically to achieve complete visual processing ( 54 ).…”

Structural covariance, topological organization, and volumetric features of amygdala subnuclei in posttraumatic stress disorder

“…The superficial amygdala (SFA) is primarily composed of excitatory neurons, and related to affective, olfactory, and social processing ( Šimić et al, 2021 ). Despite these functional differences, studies investigating amygdala subnuclei functional connectivity in PTSD ( Brown et al, 2014 , Koch et al, 2016 , Leite et al, 2022 , Liu et al, 2021 , Neumeister et al, 2016 , Rabellino et al, 2016 , Zhu et al, 2017 , Zhu et al, 2018 , Nicholson et al, 2015 , Nicholson et al, 2017 , Nicholson et al, 2016 ) suffer from a number of limitations, including very small sample sizes (e.g., 10; 19), which might prevent detection of group differences in amygdala activity ( Faber and Fonseca, 2014 ); the use of low-resolution magnetic resonance imaging (MRI) scanners (e.g., 1.5 T scanner; 23, 24), which makes delineating subcortical structures difficult ( Sladky et al, 2013 ); and typical analysis steps, such as smoothing, that further compromise the spatial specificity of the image ( Sacchet and Knutson, 2013 ).…”