Disruption within brain default mode network in postpartum women without depression

Abstract

Previous studies have demonstrated that cognitive dysfunction is associated with neurophysiological changes in postpartum period. This study aimed to investigate the intrinsic functional connectivity (FC) pattern within the default mode network (DMN) and its associations with cognitive dysfunction in postpartum women without depression revealed by resting-state functional magnetic resonance imaging (fMRI). Resting-state fMRI scans were acquired from 21 postpartum women and 21 age- and education-matched nulliparous women. The posterior cingulate cortex (PCC) was selected as the seed region to detect the FC patterns and then determine whether these changes were related to specific cognitive performance. Compared with the nulliparous women, postpartum women had a significantly decreased FC between the PCC and the left medial prefrontal cortex (mPFC). After correcting for age and education, the reduced FC between the PCC and the left mPFC was positively correlated with the poorer Clock-Drawing Test (CDT) scores in postpartum women ( r = 0.742, P < .001). The present study mainly demonstrated decreased resting-state FC pattern within the DMN regions that was linked with impaired cognitive function in postpartum women. These findings illustrated the potential role of the DMN in postpartum women that will provide novel insight into the underlying neuropathological mechanisms in postpartum period.

Decreased brain functional connectivity associated with cognitive dysfunction in women with second pregnancy

“…Alterations in endogenous sex steroid hormone levels during the postpartum period may result in widespread neural changes, including in the PCC ( Fisher et al, 2016 ). Furthermore, our previous study had mainly demonstrated decreased resting-state FC patterns within the DMN regions, especially the PCC, which were associated with impaired cognitive function in primiparous women without depression ( Zheng et al, 2020 ). Therefore, our findings indicate that reduced PCC connectivity pattern within the DMN may be responsible for the impaired short-term memory in parous women, which is different from that in primiparous women.…”

“…Our combined ALFF and ReHo analyses revealed reduced neuronal activity, mainly in the PCC and prefrontal cortex, which was associated with executive dysfunction in primiparous women ( Zheng et al, 2018 ). Furthermore, compared with the nulliparous women, postpartum women had a significantly decreased FC between the PCC and the left mPFC ( Zheng et al, 2020 ). The current study extends the work that aberrant brain connectivity in the prefrontal cortex may play a pivotal role in postpartum cognitive impairment, especially the executive dysfunction.…”

“…Multimodal neuroimaging techniques have been used to investigate the brain structural and functional alterations in primiparous women, which are linked with cognitive dysfunction ( Kim et al, 2010 ; Postma et al, 2014 ; Hoekzema et al, 2017 ; Zheng et al, 2018 , 2020 ). Hoekzema et al (2017) confirmed that primiparous women exhibited a symmetrical pattern of extensive gray matter (GM) reductions throughout pregnancy, mainly affecting the bilateral lateral prefrontal and temporal cortex.…”

“…During cognitive processing, the PCC is functionally linked to the DMN regions, such as the mPFC ( Fransson and Marrelec, 2008 ; Li et al, 2020 ). Several studies have reported reduced resting-state functional connectivity (FC) in DMN regions involved in social cognition in postpartum women ( Xiao-Juan et al, 2011 ; Chase et al, 2013 ; Zheng et al, 2020 ). Moreover, aberrant brain activity of the PCC in postpartum women has also been detected in prior studies ( Zheng et al, 2018 ; Bak and Nah, 2021 ).…”

The maternal brain is more flexible and responsive at rest: effective connectivity of the parental caregiving network in postpartum mothers

“…Changes in resting-state brain function associated with motherhood may uncover global, generalised changes in brain function, with broader impacts for maternal behaviour, beyond responses to infant stimuli. A small number of seed-based resting-state connectivity studies have measured connectivity in a priori defined networks, and these studies have shown differences between mothers and non-mothers in six key regions of the putative parental caregiving network: the dorsomedial prefrontal cortex, ventromedial prefrontal cortex, parahippocampal gyrus, posterior cingulate cortex, amygdala, and nucleus accumbens 3,18,22,24,[28][29][30] (Figure 1a). Resting-state functional connectivity between the amygdala, nucleus accumbens, and dorsomedial prefrontal cortex are related to positive maternal care.…”