Search bioRxiv⌕ Search
Home/Archive/bioRxiv

bioRxiv · 10.64898/2026.10.24.761584

Physiological Oscillations of Lateral Ventricular Volume Revealed by Fast fMRI: Effects of Aging and Vigilance

Wang, L.·Wright, A. M.·Zhao, Y.·Tong, Y.·Allen, J. W.·Wen, Q.
View original source ↗Export metadata ↓

Abstract

Abstract Background: Cyclic ventricular deformation may contribute to CSF displacement. However, the physiological mechanisms underlying ventricular motion remain poorly understood. This study characterized physiological oscillations of lateral ventricular volume (LVV) and examined their associations with aging and vigilance. Methods: We analyzed two fast resting-state fMRI scans from 99 adults aged 35-82 years. The first scan was acquired during eyes-open wakefulness, followed by 30 min of eyes-closed rest and a second scan during eyes-closed drowsiness. LVV was estimated for each image volume using automated ventricular segmentation, yielding time-resolved volume measurements. Temporal variability was quantified using the standard deviation and coefficient of variation, and spectral power was quantified for low-frequency, respiratory, and cardiac oscillations. Age-related associations were assessed using multiple linear regression adjusted for sex. Awake-drowsy differences were assessed using paired t-tests. False discovery rate correction was applied for multiple comparisons in all analyses. Results: After quality-control exclusions, 97 participants were analyzed. LVV exhibited distinct low-frequency, respiratory, and cardiac oscillatory components. Respiratory and cardiac oscillations accounted for 37.7% and 38.4% of total physiological spectral power, respectively, compared with 23.9% for low-frequency oscillations. Mean lateral ventricular volume increased with age (FDR-adjusted p = 0.010), while respiratory and cardiac power also showed positive associations with age, although neither survived FDR correction (both FDR-adjusted p = 0.067). The transition to eyes-closed drowsiness was associated with greater LVV fluctuation magnitude, reflected by increases in standard deviation (FDR-adjusted p < 0.001) and coefficient of variation (FDR-adjusted p = 0.028) and accompanied by increased low-frequency (FDR-adjusted p < 0.001) and respiratory power (FDR-adjusted p = 0.015). Mean LVV and cardiac power did not change significantly between conditions. Conclusions: LVV exhibits prominent respiratory and cardiac oscillations in addition to low-frequency fluctuations, suggesting that ventricular dynamics reflect multiple physiological influences rather than a single dominant physiological driver. Aging was primarily associated with ventricular enlargement, whereas reduced vigilance was accompanied by increased LVV fluctuation magnitude, primarily reflected in increased low-frequency and respiratory power, without a change in mean LVV. Time-resolved LVV provides a complementary approach for investigating the physiological regulation of ventricular dynamics in health and disease. Keywords: Cerebrospinal fluid; Lateral ventricular volume; Fast fMRI; Physiological oscillations; Cardiac pulsation; Respiration; Low-frequency oscillations; Aging; Vigilance

Explore related subjects

bioengineeringPreprint

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Wang, L., Wright, A. M., Zhao, Y., Tong, Y., Allen, J. W., Wen, Q.. 2026-10-27. Physiological Oscillations of Lateral Ventricular Volume Revealed by Fast fMRI: Effects of Aging and Vigilance. https://doi.org/10.64898/2026.10.24.761584

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

KEEP EXPLORING

Related preprints

bioRxiv2026

Mesoscale Soft Robotics for Mechanically Perturbing and Functionally Monitoring Responses in Human Organoids

Human organoids represent promising models for studies of significance to the biology and medical communities. Of the existing approaches for monitoring organoids, none offers the ability to apply programmable mechanical forces while simultaneously recording multi-modal physiological responses, of relevance to phenomena spanning from traumatic brain injuries to cardiac rhythm disorders. Here, we present a mesoscale soft robotic organoid interface that enables programmable delivery of forces to organoids of diverse shapes, and to map electrophysiological activity and mechanical responses. The platform combines actuation elements with integrated sensors for quantitative measurement and control. Studies using this technology reveal that spheroidal cortical organoids exhibit distinct responses to mechanical trauma, including silencing, recovery, and changes in neuronal firing patterns. Additional experiments on cardiac ring tissues demonstrate that sustained stretching induces beat-to-beat rhythm variability and altered conduction. The results establish a framework for investigating force-triggered transitions between physiological and disease-like states in human tissue models.

bioengineering↗
bioRxiv2026

Few-shot regulatory sequence design with a genomic language model

A central challenge in generative biology is translating knowledge learned from natural sequences and experiments into designs with desired functions. In-context learning (ICL) is an emergent capability of large language models that allows them to adapt to new tasks from a few examples without additional training, enabling these models to become general-purpose learners. Here, we show that the genome language model, Evo 2, exhibits generative ICL in biological sequence design. Prompting with just tens of examples conditions Evo 2 to generate novel and diverse regulatory DNA sequences without any additional training. Mechanistic analysis suggests that genomic ICL may originate from induction, similar to phenomena observed in natural language. Reinforcement learning leveraging sequence-to-function models as experiment-derived rewards further strengthens ICL. We first validate this approach by generating enhancers that drive cell-type-specific gene expression in three human cell lines. Extending this approach in vivo, enhancers designed using human regulatory element data selectively label layer 5 extratelencephalic neurons in the mouse cortex with high specificity and stronger activity than existing enhancers. Our study provides evidence of emergent properties in genomic sequence models and introduces a promising approach for improving functional conditioning in generative biology.

bioengineering↗
bioRxiv2026

IOP-independent treatment for neurodegeneration in glaucoma using optimized ROS-scavenging microparticles for sustained release of erythropoietin

Glaucoma is a slow-progressing neurodegenerative disease of the optic projection to the brain and a leading cause of blindness worldwide. Current treatments are targeted towards lowering intraocular pressure (IOP), the only known, modifiable risk factor; however, this strategy is ineffective in many patients. An early hallmark of glaucomatous neurodegeneration is increased reactive oxygen species (ROS), representing an alternative opportunity for intervention to halt or slow disease progression. In this work, we optimize a ROS-scavenging copolymer, poly(propylene sulfide-co-ethylene sulfide) (PPSES), for formulation of size-controlled, stabilized, antioxidant microparticles (MPs) for sustained release of the protein erythropoietin (EPO). EPO promotes biological antioxidant defense via activation of NRF2-mediated transcription of antioxidant genes. This MP system overcomes the short half-life of EPO and leverages the combined benefits of bioactive EPO with long-lasting, inherently antioxidant PPSES MPs. The lead EPO-MP formulation preserves neurons in both mouse and non-human primate models of glaucoma through suppression of oxidative stress and optic nerve degeneration. EPO-loaded PPSES MPs represent a translationally relevant therapy for long-term management of glaucoma independent of IOP.

bioengineering↗