Contrast enhanced magnetic resonance imaging highlights neurovasculature changes following experimental traumatic brain injury in the rat

Abstract

Neurovascular injury has been proposed as a universal pathological hallmark of traumatic brain injury (TBI) with molecular markers of angiogenesis and endothelial function associated with injury severity and morbidity. Sex differences in the neurovasculature response post-TBI may contribute to the differences seen in how males and females respond to injury. Steady-state contrast enhanced magnetic resonance imaging (SSCE-MRI) can be used to non-invasively assess the neurovasculature and may be a useful tool in understanding and predicting outcomes post-TBI. Here we used SSCE-MRI to investigate the neurovasculature of male and female rats at 48 h after an experimental TBI, and how these changes related to neuromotor function at 1-week post-TBI. In addition to TBI induced changes, we found that female rats had greater vessel density, greater cerebral blood volumes and performed better on a neuromotor task than their male counterparts. These results suggest that acute post-TBI cerebrovascular function is worse in males, and that this may contribute to the greater functional deficits observed post-injury. Furthermore, these results highlight the potential of SSCE-MRI to provide insights into the cerebral microvasculature post-TBI. Future studies, incorporating both males and females, are warranted to investigate the evolution of these changes and the underlying mechanisms.

Demographic reporting across a decade of neuroimaging: a systematic review

“…2 , Supplementary Table 2 ). In addition to inclusion of both biological sexes, the NIH implemented a related policy in 2016 requiring the use of sex as a biological variable given documented differences in anatomy, physiology, disease presentation, and patient outcomes (Bonkhoff et al 2021 ; Liu et al 2020 ; Wright et al 2020 ). Utilizing 488 subjects in the HCP database, Liu et al observed significant differences in brain structure.…”

White and gray matter integrity evaluated by MRI-DTI can serve as noninvasive and reliable indicators of structural and functional alterations in chronic neurotrauma

“…In contrast, only the male rats exhibited worse white matter integrity in the corpus callosum following rmTBI, not in female rats 68 . Furthermore, compared to male rats, female rats had superior vessel density and better neuromotor function following rmTBI 69 . These sexual dimorphisms in TBI responses may be in part due to endocrine-related differences, such as sex hormones 70 .…”

Spatial amine metabolomics and histopathology reveal localized brain alterations in subacute traumatic brain injury and the underlying mechanism of herbal treatment

“… 61 In addition, it cooperates with neurogenesis to promote brain recovery. 62 , 63 Previous studies demonstrated that microvascular density is compromised acutely after TBI. 63 Then, the cerebral capillaries slowly reestablished to baseline levels within 2 weeks.…”