Biology subjects

Pauls, A.

Publications and source records attributed to Pauls, A..

3 recordsLinked to original sources

bioRxiv2025

Time- and frequency-resolved decomposition of beta brain activity reveals two functionally distinct beta bands

Oscillatory brain activity in the beta (13-30 Hz) range plays a central role in sensorimotor and other healthy brain processes and is a potential disease biomarker. However, even in the well-studied sensorimotor system, inconsistencies remain concerning betas differential role in maintaining and terminating movement. Emerging evidence suggests that beta comprises two frequency ranges, a lower (<20 Hz) and a higher (>20 Hz) subrange. Moreover, beta occurs in transient events which correlate with perception and action. We here use human whole-brain magnetoencephalography (MEG) recordings and a Hidden Markov Model based analysis approach to discover whole-brain beta-band activity during rest and a naturalistic motor task in a data-driven manner. We successfully delineate two anatomically and functionally distinct beta band components which coexist throughout the neocortex. Low-beta (<20 Hz) events are very rare, high amplitude events, whereas high-beta (>20 Hz) is common but lower in amplitude. Both bands show state-specific anatomical distribution and modulation during a motor task: Low-beta is entirely absent during movement, whereas high-beta is only partially suppressed and reoccurs during postural maintenance. During post-movement beta rebound, low-beta event probability increases threefold, accompanied by strong low-beta event synchronization. A third state, probably corresponding to gamma activity, is active during task execution. Beta rebound occurs via a directed, sequential shift from gamma/active state via high-beta state to low-beta state. Our results provide strong experimental evidence for the coexistence of two functionally and anatomically distinct beta bands, and provide insights into their role in movement initiation, maintenance, and termination. Short abstractThe brains beta band activity is modulated by sensorimotor processing, but inconsistencies remain concerning betas role in maintaining and terminating movement. Mounting evidence points towards two beta bands with distinct functional roles. We use human whole-brain magnetoencephalography and a data-driven Hidden Markov Model based analysis approach to detect whole-brain beta-band activity. We delineate two anatomically and functionally distinct beta band states: a rarely occurring low-beta (<20 Hz) and a common high-beta (>20 Hz) state. During movement, low-beta is completely absent, whereas high-beta is only partially suppressed. During post-movement beta rebound, only low-beta increases significantly, accompanied by pronounced low-beta synchronization. Activity in gamma state increases during movement. Beta rebound occurs via a sequential shift from gamma via high-beta to low-beta state. Our results provide strong experimental evidence for the coexistence of two functionally and anatomically distinct beta bands and provide insights into their role in movement initiation, maintenance and termination.

neuroscience↗

bioRxiv2025

The Lettuce Expression Browser: from lab to LEB

Lettuce (Lactuca sativa L.) is an economically important leafy vegetable within the Asteraceae family, cultivated worldwide across diverse agricultural systems. Recent advances in genomic and transcriptomic resources have positioned lettuce as a promising model system for functional genomics in the Asteraceae. However, currently available gene expression datasets lack comprehensive tissue-specific resolution, primarily focus on a single cultivar and are not visualised in an interpretable manner, limiting their utility for broader genetic and physiological studies. To bridge this gap, we developed the Lettuce Expression Browser (LEB), a publicly available platform providing high-resolution gene expression maps across various organs, tissues and developmental stages in both cultivated and wild lettuce species. The LEB integrates transcriptomic data from finely dissected seedlings, shoot tissues at various developmental stages and seedlings subjected to abiotic stresses (salt and far-red), visualised using the ggPlantmap R package. This platform offers an intuitive interface for exploring gene expression patterns and serves as a valuable resource for those studying lettuce development, stress responses, and evolutionary genomics. The LEB is hosted on the LettuceKnow Web Portal (https://lettuce.bioinformatics.nl) and can be expanded to include additional datasets, enhancing its role as a key tool for lettuce research and crop improvement. Significance statementThe Lettuce Expression Browser (LEB) provides the first high-resolution gene expression atlas for both cultivated and wild lettuce species. This open-access resource enables detailed exploration of gene activity across development stages and stress conditions, advancing functional genomics in the Asteraceae family.

plant biology↗

bioRxiv2023

Human sensorimotor resting state beta events and 1/f response show good test-retest reliability

Neurological conditions affecting the sensorimotor system have a profound impact on individuals physical independence and are associated with a considerable socioeconomic burden. Reliable functional biomarkers allowing early diagnosis of these conditions or targeting treatment and rehabilitation can reduce this burden. Magnetoencephalography (MEG) can non-invasively measure the brains salient rhythmic patterns such as the somatomotor ( rolandic) rhythm. This rhythm shows intermittent high amplitude events in the beta (14-30 Hz) frequency range which predict behavior across tasks and species and are altered by neurological diseases affecting the sensorimotor system. Thus, the sensorimotor resting beta phenotype is a promising candidate biomarker of sensorimotor function. A prerequisite for use as a biomarker is that it can be quantified reliably across different measurement sessions. Here, using MEG, we assessed the test-retest stability of spontaneously occurring sensorimotor power spectral characteristics, including both aperiodic (1/f) as well as beta band fluctuations ( beta events) in a cohort of 50 healthy human controls. Test-retest reliability across two separate measurement sessions was assessed using the intraclass correlation coefficient (ICC). Beta events were determined using a thresholding-based approach on a narrow-band filtered amplitude envelope obtained using Morlet wavelet decomposition across a range of parameters (recording length, amplitude threshold and filtering bandwidth). We find that both aperiodic power spectral features as well as several beta event characteristics show good to excellent testretest stability. Especially aperiodic component power spectral features (ICC 0.77-0.88), but also measures of beta event amplitude (ICC 0.74-0.82) were found to be very stable, while measures of individual beta event duration were less reliable, especially for the left hemisphere (ICC right [~]0.7, left [~]0.55). Recordings of 2-3 minutes were sufficient to obtain stable results for most parameters. Important for potential clinical applications, automatization of beta event extraction was successful in 86 % of cases. Beta event rate and duration measures were more sensitive to analysis parameters than the measures of event amplitude. The results suggest the sensorimotor beta phenotype is a stable feature of an individuals resting brain activity even for short, 2-3 minute recordings which can be easily measured in patient populations, facilitating its use as a potential clinical biomarker.

neuroscience↗