What this means
The brainstem is vulnerable to aging and prodromal synucleinopathy, yet whether these processes disrupt shared or distinct functional pathways linking the brainstem to the cortex remains unknown. Using high-resolution 7-Tesla fMRI, we mapped connectivity between 58 brainstem nuclei and cortical regions in young adults, older adults and individuals with isolated REM sleep behavior disorder (iRBD), a prodromal synucleinopathy.
A plain-English summary is on its way. Until then, this is the start of the authors' own summary.
- Who it was tested in
- Not stated
- Kind of research
- Early results, not yet checked by other scientists
The science
- Original title
- Charting vulnerability of brainstem functional pathways in aging and prodromal synucleinopathy
- Authors
- Hua, L., Singh, K., Garcia-Gomar, M. G. et al.
- Journal
- bioRxiv (preprint, not yet peer reviewed)
- Published
- Oct 28, 2026
- Study type
- Preprint
Abstract
The brainstem is vulnerable to aging and prodromal synucleinopathy, yet whether these processes disrupt shared or distinct functional pathways linking the brainstem to the cortex remains unknown. Using high-resolution 7-Tesla fMRI, we mapped connectivity between 58 brainstem nuclei and cortical regions in young adults, older adults and individuals with isolated REM sleep behavior disorder (iRBD), a prodromal synucleinopathy. Long-range brainstem-cortical connectivity weakened with aging and further in iRBD. However, the two conditions affected distinct systems: aging involved arousal- and cognition-related nuclei and association cortex, whereas iRBD involved sleep- and autonomic-related nuclei and extended to sensory-motor cortex. These alterations were associated with distinct neurophysiological, metabolic and neurotransmitter architectures and spatial transcriptomic signatures. Brainstem-cortical connectivity also followed the cortical unimodal-transmodal hierarchy, with reduced differentiation in aging. Independent 3-Tesla data reproduced the broader connectivity patterns. Together, our findings reveal shared and distinct multiscale patterns of brainstem pathway vulnerability in aging and prodromal synucleinopathy.
Hua, L., Singh, K., Garcia-Gomar, M. G. et al. Charting vulnerability of brainstem functional pathways in aging and prodromal synucleinopathy. bioRxiv. 2026. doi:10.64898/2026.10.27.760186. https://doi.org/10.64898/2026.10.27.760186