Biology subjects

Meyer-Baese, L.

Publications and source records attributed to Meyer-Baese, L..

6 recordsLinked to original sources

bioRxiv2026

Behavior Differentially Shapes Spontaneous Cortical Network Dynamics Across Frequencies

The rapid and coordinated propagation of neural activity across a network of distributed brain regions underpins complex behavior and cognition. Yet how multiple distributed processes are facilitated in parallel across timescales and behavioral states remains unclear. Using simultaneous fast wide-field voltage and hemodynamic imaging in awake mice, we show that behavior differentially shapes cortical network dynamics across frequencies and signal types. Although static functional connectivity preserved canonical networks across frequencies, the underlying dynamics diverged. Low-frequency and hemodynamic activity were dominated by behavior-dependent persistence of network states, whereas higher-frequency activity exhibited stable network structure with modulation through changes in state expression. Despite these differences, shared network organization was preserved across timescales and signal types. This indicates that similar functional connectivity can arise from distinct temporal dynamics. These findings reveal that cortical networks are governed by frequency-dependent principles through which behavior shapes the persistence and expression of large-scale brain states.

neuroscience↗

bioRxiv2026

Connectomes across temporal scales with simultaneous wide-field optical imaging and resting-state functional MRI

Resting-state functional MRI (rs-fMRI) is a cornerstone of human brain research, yet its interpretation is complicated by its sensitivity to the slow hemodynamic response that obscures the organization of neural activity across faster time scales. Here we use simultaneous wide-field optical imaging (WOI) and rs-fMRI to directly examine the relationship between neural and hemodynamic functional connectomes across time scales. We show that much of the large-scale spatial structure is preserved across modalities, across time scales, and across frequencies. Although rs-fMRI robustly captures time-averaged neural activity, time-resolved rs-fMRI estimates of functional connectivity exhibit significantly greater variability, which partially reflects sensitivity limitations. Hemodynamic WOI signals maintain greater similarity to neural activity than rs-fMRI, although their fidelity is reduced at high frequencies. Together, our findings demonstrate that the time-averaged spatial structure of neural activity is faithfully represented in hemodynamics and rs-fMRI; provide insight into the reliability of time-resolved rs-fMRI across temporal scales; and establish a multimodal framework for validating features of dynamic brain activity. TeaserSpatial patterns of neural activity present across time scales are largely preserved in hemodynamics measured with optical imaging and rs-fMRI.

neuroscience↗

bioRxiv2026

An integrated platform for simultaneous wide-field voltage/calcium imaging and fMRI (EPI & ZTE) reveals neuronal infraslow dynamics underlying functional connectivity

Wide-field optical imaging acquired simultaneously with functional MRI (fMRI) has the ability to provide unprecedented insight into the neural origins of time-varying whole-brain activity. Simultaneously linking cellular-scale activity to whole-brain fMRI remains challenging due to optical access, RF coil placement, and transmission constraints in the MRI environment. We present an integrated platform that combines a long-distance tube-lens optical path (>98% transmission), a chronically stable optically-fused cranial window, and a subject-conformal RF surface coil compatible with both echo planar imaging (EPI) and zero-echo-time (ZTE) fMRI. The system supports concurrent wide-field imaging of genetically encoded voltage or calcium indicators concurrently with intrinsic hemoglobin signals. In individual mice, wide-field optical and fMRI measures yield concordant functional connectivity, and cross-modal timing analyses demonstrate that neuronal infraslow dynamics (<0.1 Hz) underlie the majority of fMRI connectivity, after removing hemodynamic crosstalk. The platform's sensitivity, chronic stability, and sequence flexibility broaden access to cellular-to-whole-brain investigations across basic and translational neuroimaging.

neuroscience↗

bioRxiv2024

Variation in the Distribution of Large-scale Spatiotemporal Patterns of Activity Across Brain States

A few large-scale spatiotemporal patterns of brain activity (quasiperiodic patterns or QPPs) account for most of the spatial structure observed in resting state functional magnetic resonance imaging (rs-fMRI). The QPPs capture well-known features such as the evolution of the global signal and the alternating dominance of the default mode and task positive networks. These widespread patterns of activity have plausible ties to neuromodulatory input that mediates changes in nonlocalized processes, including arousal and attention. To determine whether QPPs exhibit variations across brain conditions, the relative magnitude and distribution of the three strongest QPPs were examined in two scenarios. First, in data from the Human Connectome Project, the relative incidence and magnitude of the QPPs was examined over the course of the scan, under the hypothesis that increasing drowsiness would shift the expression of the QPPs over time. Second, using rs-fMRI in rats obtained with a novel approach that minimizes noise, the relative incidence and magnitude of the QPPs was examined under three different anesthetic conditions expected to create distinct types of brain activity. The results indicate that both the distribution of QPPs and their magnitude changes with brain state, evidence of the sensitivity of these large-scale patterns to widespread changes linked to alterations in brain conditions.

neuroscience↗

bioRxiv2022

Cortical networks relating to arousal are differentially coupled to neural activity and hemodynamics

Even in the absence of specific sensory input or a behavioral task, the brain produces structured patterns of activity. This organized activity is modulated by changes in arousal. Here, we use wide-field voltage imaging to establish how arousal relates to cortical network voltage and hemodynamic activity in spontaneously behaving head-fixed male and female mice expressing the voltage-sensitive fluorescent FRET sensor Butterfly 1.2. We find that global voltage and hemodynamic signals are both positively correlated with changes in arousal with a maximum correlation of 0.5 and 0.25 respectively at a time lag of 0 seconds. We next show that arousal influences distinct cortical regions for both voltage and hemodynamic signals. These include a broad positive correlation across most sensory-motor cortices extending posteriorly to the primary visual cortex observed in both signals. In contrast, activity in prefrontal cortex is positively correlated to changes in arousal for the voltage signal while it is a slight net negative correlation observed in the hemodynamic signal. Additionally, we show that coherence between voltage and hemodynamic signals relative to arousal is strongest for slow frequencies below 0.15 Hz and is near zero for frequencies greater than 1Hz. We finally show that coupling patterns are dependent on the behavioral state of the animal with correlations being driven by periods of increased orofacial movement. Our results indicate that while hemodynamic signals show strong relations to behavior and arousal, these relations are distinct from those observed by voltage activity. Significance StatementWe leverage wide-field voltage imaging to examine the relation between cortical changes in membrane potential dynamics and hemodynamics. These two signals are then examined with respect to changes in arousal, as measured by pupil diameter, in awake head fixed mice. Our results show similarities as well as important differences in the correlation of arousal with neuronal population activity dynamics and the hemodynamic signal. Further, the spatial activity correlation maps with arousal depended differentially on the behavioral state of the animal in a frequency dependent manner. Our results indicate that the modulation of brain networks by arousal is dynamically regulated, and only partly overlap between functional networks determined from hemodynamic or voltage activity.

neuroscience↗

bioRxiv2020

Spatial modulation of dark versus bright stimulus responses in mouse visual cortex

A fundamental task of the visual system is to respond to luminance increments and decrements. In primary visual cortex (V1) of cats and primates, luminance decrements elicit stronger, faster, and more salient neural activity (OFF responses) than luminance increments (ON responses). However, studies of V1 in ferrets and mice show that ON responses may be stronger. These discrepancies may arise from differences in species, experimental conditions, or from measuring responses in single neurons versus populations. Here, we examined OFF versus ON responses across different regions of visual space in both single neurons and populations of mouse V1. We used high-density silicon probes and whole-cell patch-clamp recordings to assess OFF versus ON dominance in local field potential (LFP), single neuron, and membrane potential responses. Across these levels, we found that OFF responses clearly dominated in the central visual field, whereas ON responses were more evident in the periphery. These observations were clearest in LFP and subthreshold membrane potential. Our findings consolidate and resolve prior conflicting results and reveal that retinotopy may provide a common organizing principle for spatially biasing OFF versus ON processing in mammalian visual systems.

neuroscience↗