Search bioRxiv⌕ Search

bioRxiv · 10.64898/2026.05.02.722426

Ultrafast venous and sagittal sinus constrictions in the brain driven by abdominal pressure

Abstract

Nearly all the blood supplying the cortex exits via the bridging veins (BVs) that drain into the superior sagittal sinus (SSS), making these vessels key chokepoints for cerebral blood flow. Using optical imaging in head-fixed mice, we found that the SSS and BVs exhibit ultrafast contractions (<0.1 s) at the onset of locomotion, following whisker stimulation, and upon awakening from sleep. Contractions of the BV and SSS were strongly correlated with abdominal muscle EMG activity and were tightly correlated with respiration at rest. The rapid decrease in blood volume caused by venous constrictions resulted in spurious increases in fluorescence in mice expressing fluorescent reporter proteins, creating artifacts that mimic functional signals. Venous contractions with the same amplitude and dynamics could be generated in anesthetized mice by abdominal pressure application, showing that these contractions were generated by mechanical coupling with the abdomen. Externally imposed abdominal pressures also drove a rapid but transient increase in blood flow. Unlike the pial and parenchymal microvasculature whose diameters are controlled by local signals, the diameters of SSS/BV are dynamically controlled during behavior by abdominal muscle regulation of intracranial pressure, establishing a pathway for regulation of cerebral hemodynamics via mechanical coupling between the central nervous system and the viscera.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Zhang, Q., Garborg, C. S., Frank, N., Salehi Shahrbarbaki, F., Turner, K., Drew, P. J.. 2026-05-06. Ultrafast venous and sagittal sinus constrictions in the brain driven by abdominal pressure. https://doi.org/10.64898/2026.05.02.722426

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

Attention Across Scales: From Individual Variation to Social Hierarchies and Brain Networks in Semi-Free-Ranging Macaques

Attention is a fundamental brain function supporting perception, decision-making, and social behavior, and its dysfunction profoundly impairs daily life. It is both dynamic and stable, varying across observations and individuals, changing across the lifespan, and being shaped by social and environmental experience. Yet capturing this complexity remains a central challenge in neuroscience. Here, we integrated longitudinal behavioral assessments of semi-free-ranging macaques living in naturalistic social groups with resting-state fMRI. We quantified performance across days, ages, and social hierarchies and related it to intrinsic brain organization. Distinct attentional phenotypes emerged, including individuals with reduced attentional control. Performance followed an inverted-U lifespan trajectory, improving from childhood to adulthood before declining. Social status modulated attentional performance. Critically, nonlinear lifespan trajectories and associations with individual attentional differences were most clearly expressed in frontoparietal connectivity. Together, these findings reveal how sustained attention is organized across scales, providing a biological framework for its individual diversity, social modulation, and neural basis.

neuroscience↗

Decoding natural scenes from patterned optogenetic responses in mouse visual cortex

A central challenge in developing visual cortical prostheses is to determine how visual stimuli should be transformed into effective patterns of cortical stimulation. Although advances in stimulation technologies, including optogenetics, provide increasingly precise control over cortical activity, it remains unclear whether artificially evoked activity can reproduce the information content of naturally evoked visual representations. Here we establish a quantitative framework for evaluating visual encoding strategies by decoding cortical responses evoked by natural vision and patterned optogenetic stimulation. We developed a novel dual-modal paradigm in awake mice to bridge the gap between endogenous photostimulation and artificial network driving. By co-expressing the high-performance calcium indicator GCaMP6s and the red-shifted, ultra-sensitive opsin rsChRmine-oScarlet in the primary visual cortex (V1), we successfully translated dynamic natural movie frames into patterned, spatiotemporal optogenetic stimulation. Quantitative comparisons of macro-scale dynamics demonstrated that this patterned optogenetic injection evokes cortical states highly comparable and representationally aligned with those driven by actual visual photostimulation. To systematically evaluate the fidelity of these responses, we developed STAR, a deep learning model featuring spatial and temporal attention mechanisms, and successfully reconstructed the frames of natural movies from V1 signals under both experimental modalities. Collectively, our results demonstrate that complex sensory information can be both naturally encoded and synthetically injected into V1 circuits with high decoding fidelity. This work provides an empirical and computational proof-of-concept for intelligent, closed-loop biomimetic encoders, establishing a robust framework for next-generation cortical visual neuroprostheses and bidirectional brain-machine interfaces.

neuroscience↗

Why Is Spontaneous Blink Timing Informative? An Adaptive Scheduling Perspective

Spontaneous eye blinks have long been linked to cognitive processing, yet how task demands shape blink timing and its relationship to behavioral performance remains unclear. We examined spontaneous blink behavior in 576 adults performing two variants of the Continuous Performance Task (CPT). Blink occurrence and timing were most strongly modulated by the experimental condition in the more demanding CPT-AX task, whereas their association with response time was stronger in the CPT-X task, where more consistent blink timing predicted faster responses. This dissociation suggests that task structure changes not only blink behavior but also the behavioral relevance of blink timing. These findings are consistent with an adaptive scheduling account of spontaneous blinking and provide a conceptual framework for understanding when and why blink timing contains chronometric information about ongoing cognition.

neuroscience↗