Biology subjects

Pei, M.

Publications and source records attributed to Pei, M..

11 recordsLinked to original sources

bioRxiv2026

Functional ultrasound imaging in free-moving marmosets reveals that intra-call prosodic features modulate large-scale cortical dynamics

Vocal turn-taking relies on sequential structure and rhythmic timing, yet how primate brains integrate these features across timescales in naturalistic, free-moving contexts is unclear. We developed functional ultrasound imaging for free-moving marmosets, combining an exogenous marker-based workflow for robust registration from non-standard imaging planes with preprocessing pipeline optimized to reduce locomotion artifacts. We systematically perturbed sequential and rhythmic features of interactive phee calls across hierarchical timescales. Cortical networks showed selective sensitivity to intra-call structure: disrupting phrase sequences increased activity in auditory and para-insular cortices and strengthened inter-subject functional connectivity within this network. Rhythmic manipulations primarily affected core auditory cortex: shortening inter-phrase intervals enhanced responses, whereas lengthening intervals suppressed them. These findings establish a practical framework for free-moving primate neuroimaging and identify intra-call prosodic features as promising targets for mechanistic investigation.

neuroscience↗

bioRxiv2026

CynoBrain: A unified high-resolution framework for cross-modal data integration for macaque brain mapping

The cynomolgus macaque is a widely used primate model in neuroscience, yet existing brain atlas resources remain limited in resolution and lack a standardized framework for integrating structural, molecular, and connectivity data within a common reference space. Here we present CynoBrain, a high-resolution multi-modal brain atlas constructed from population-averaged MRI data at 9.4 Tesla, yielding a 75 micron isotropic template with significant improvement in resolution. A co-registered whole-brain autofluorescence template resolves cytoarchitectural boundaries not visible in MRI template. Three major parcellation schemes, D99 143-area, M132 105-area, and SARM are incorporated in CynoBrain space. Spatial transcriptomic based laminar definition, reconstructed from 2D sections into volumetric common space, provides a six-layer cortical segmentation spanning the whole cortex. As a demonstration of the integrative capability of this framework, 2D retrograde tracing data is reconstructed and mapped to the Cynobrain space, enabling volumetric compilation of 2D macaque brain mapping data across subjects. An online interactive platform was constructed to allow full access to Cynobrain, establishing it as a scalable, open platform for cross-modal data integration for primate neuroscience. Overall, CynoBrain is a unified framework for cross-modal data integration for macaque brain mapping with high-resolution, multiple atlases and transcriptomic based laminar definition.

neuroscience↗

bioRxiv2025

Macroscopic cerebral energy efficiency corresponds to neuron reorganization in awake and anesthetized mice

Non-invasive imaging of brain function and energy supply is crucial for diagnosing and treating brain disorders. Conventional imaging struggles to capture altered relationships between energy supply and utilization caused by brain diseases. A novel method, which can be translated to human patients, is to calculate relative power (rPWR) and relative cost (rCST) to assess cerebral energy efficiency. However, whether rPWR/rCST can track individual changes and neural activity remains unproven. Our study compared these non-invasive measures with invasive two-photon microscopy in awake and anesthetized mice. We found that rPWR/rCST distributions were similar between awake mice and humans, but changed in anesthetized mice, indicating a shift in the brains economic balance. Furthermore, changes in rPWR/rCST were linked to the reorganization of microscopic neural networks, observed with two-photon microscopy. Our work highlights the potential of rPWR/rCST for medical applications, and that neural network reorganization is linked to the brains economic balance.

neuroscience↗

bioRxiv2024

Cerebral Blood Volume Modulates Glymphatic Influx Through Extra-ventricular Cerebrospinal Fluid Volume

The glymphatic system facilitates waste removal via cerebrospinal fluid (CSF) influx alongside perivascular spaces throughout the brain. Vasomotion, the slow motion of blood vessel (0.1-0.3 Hz), has been found to be one of the driving forces for perivascular clearance, but it is not clear whether more chronical change of vessel diameter, as reflected by macroscopic cerebral blood volume (CBV), has any impact on glymphatic function. Combining multimodal mouse MRI techniques, we investigated the relationship among glymphatic influx, CBV, CSF volume and EEG power under six different conditions (awake, dexmedetomidine, isoflurane, isoflurane/dexmedetomidine, ketamine/xylazine and awake with caffeine). We found dexmedetomidine and caffeine enhanced glymphatic influx, while isoflurane reduced it compared with awake condition. Quantitative CBV imaging revealed that glymphatic influx was negatively correlated to CBV across the above conditions. Furthermore, such negative correlation was found to be mediated in part by changes of extra-ventricular CSF volume, which was quantified using T1 MRI. Taken together, our results suggest that CBV is a consciousness independent modulator of glymphatic function and modulates glymphatic influx through extra-ventricular CSF volume. This new finding opens potential avenues to enhance brain waste clearance by regulating CBV, which could be beneficial for protein deposition related neurological diseases. TeaserCBV is a consciousness independent modulator of glymphatic function and modulates glymphatic influx through extra-ventricular CSF volume.

neuroscience↗

bioRxiv2023

Cell-type specific optogenetic fMRI on basal forebrain reveals functional network basis of behavioral preference

The basal forebrain (BF) is a complex structure that plays key roles in regulating various brain functions. However, it remains unclear how cholinergic and non-cholinergic BF neurons modulate large-scale functional networks and their relevance in intrinsic and extrinsic behaviors. With optimized awake mouse optogenetic fMRI approach, we revealed optogenetic stimulations of four BF neuron types evoked distinct cell-type specific whole-brain BOLD activations, which could attribute to BF-originated low dimensional structural networks. Additionally, optogenetic activation of VGLUT2, ChAT and PV neurons in BF modulated the preference of locomotion, exploration and grooming, respectively. Furthermore, we uncovered the functional network basis of the above BF-modulated behavioral preference, through a decoding model linking the BF-modulated BOLD activations, low dimensional structural networks, and behavioral preference. To summarize, we decoded functional network basis of differential behavioral preference with cell-type specific optogenetic fMRI on BF, and provided an avenue for investigating mouse behaviors from a whole-brain view.

neuroscience↗

bioRxiv2022

A systematically optimized awake mouse fMRI paradigm

Functional magnetic resonance imaging (fMRI) has been increasingly utilized in mice. Due to the non-negligible effects of anesthetics on mouse fMRI, it is becoming more common to perform fMRI in the awake mice. However, high stress level and head motion in awake mouse fMRI remain to be fully addressed, which limits its practical applications. Therefore, here we presented a systematically optimized awake mouse fMRI paradigm as a practical and open-source solution. First, we designed a soundproof habituation chamber in which multiple mice can be habituated simultaneously and independently. Then, combining corticosterone, body weight and behavioral measurements, we systematically evaluated the potential factors that may contribute to animals stress level for awake imaging. Among many factors, we found that the restraining setup allowing forelimbs freely moving and head tilted at 30-degree was optimal for minimizing stress level. Importantly, we implemented multiband simultaneous multi-slice imaging to enable ultrafast fMRI acquisition in awake mice. Compared to conventional single-band EPI, faster acquisition enabled by multiband imaging were more robust to head motion and yielded higher statistical power. Thus, more robust resting-state functional connectivity was detected using multiband acquisition in awake mouse fMRI, compared to conventional single-band acquisition. In conclusion, we presented an awake mouse fMRI paradigm that is highly optimized in both awake mice habituation and fMRI acquisition, and such paradigm minimized animals stress level and provided more resistance to head motion and higher statistical power.

neuroscience↗

bioRxiv2022

The wheat head blight pathogen Fusarium graminearum recruits facultative endohyphal bacteria from the soil, making the fungal-bacterial holobiont nitrogen-fixing and increasing the fungal pathogenicity

In nature, fungal endophytes often have facultative endohyphal bacteria. Can a fungal pathogen such as Fusarium graminearum, pathogenic on wheat, get facultative endohyphal bacteria from soil (FEB) and how does the FEB affect the fungal phenotype? We constructed a growth system/microcosm that allowed a molecularly well-studied F. graminearum isolate, PH-1, to grow through natural soil and then be re-isolated on a gentamicin-containing medium, allowing endohyphal growth of the bacteria while killing eventual bacteria growing on the agar medium. We had labelled the F. graminearum PH-1 with a His1mCherry gene staining the fungal nuclei fluorescent red to confirm re-isolation of the same isolate we sent through the soil. Through qPCR of the 16SrRNA gene in the bacteria using universal primers combined with qPCR of the mCherry gene of DNA from the re-isolated cultures of the Fg-FEB holobionts growing on gentamicin-containing media, it was found that most of the holobiont isolates contained about 10 16SrRNA genes per fungal mCherry gene. The Fg-FEB holobiont isolates were sub-cultured several times, and the FEB content on lab media was stable. Sequencing the 16SrRNA gene from several Fg-FEB holobiont isolates revealed known endophytic bacteria capable of nitrogen fixation. We compared the pathogenicity of one of the Fg-FEB holobionts Fg-S.maltophilia, with the background without FEB and found that it was more pathogenic than without FEB. We could also show that the bacterial 16SrRNA load per fungal His1mCherry gene inside the wheat stayed the same as in culture. Finally, we tested if the Fg-S.maltophilia was capable of nitrogen fixation and could show that it, on a nitrogen-free medium, formed a dense mycelium containing proteins at similar levels as on regular nitrogen-containing media. Our results could indicate that naturally occurring fungal pathogens outside lab conditions might contain facultative endohyphal bacteria, positively affecting their pathogenicity and ecological fitness.

ecology↗

bioRxiv2022

The regulatory landscapes of human ovarian ageing

Summary paragraphThe ovary is the first organ to age in the human body, affecting both fertility and overall health in women1-8. However, the biological mechanisms underlying human ovarian ageing remain poorly understood. Here we performed single-nuclei multi-omics analysis of young and reproductively aged human ovaries to understand the molecular and cellular basis of ovarian ageing in humans. Our analysis reveals coordinated changes in transcriptomic output and chromatin accessibility across cell types during ageing, including elevated mTOR and MAPK signaling, decreased activity of the oxidative phosphorylation and DNA damage repair pathways, and an increased signature of cellular senescence. By constructing cell type-specific regulatory networks, we uncover enhanced activity of the transcription factor CEBPD across cell types in the aged ovary, with a corresponding significant loss of activity of most cell identity-associated transcription factors. Moreover, by performing integrative analyses of our single-nuclei multi-omics data with common genetic variants associated with age at natural menopause (ANM) from genome-wide association studies, we demonstrate a global impact of functional variants on changes in gene regulatory networks across ovarian cell types. Finally, we nominate about a dozen of functional non-coding variants, their target genes and cell types and regulatory mechanisms that underlie genetic association with ANM. This work provides a comprehensive multimodal landscape of human ovarian ageing and mechanistic insights into inherited variation of ANM.

genomics↗

bioRxiv2021

Identification and characterization of 19 predicted Myb-family DNA binding proteins in Magnaporthe oryzae concerning growth, conidiation, and pathogenicity

Proteins with DNA binding Myb domains have been suggested in regulating development and stress responses. Magnaporthe oryzae is considered the most destructive pathogen of rice. We screened the genome for genes with Myb domains encoding since these can be needed for pathogenesis. We found Myb1-19. Only MoMyb1 was previously shown to be involved in pathogenesis. We succeeded in deleting 12 of the other 18 genes. MoMyb2 deletion affected mainly growth, while MoMyb13 or MoMyb15 deletions gave additional defects in conidiation and plant infection. However, RT-qPCR showed that none of the 19 Myb genes are negligibly expressed. Instead, they have different expression profiles hours post-infection when infecting rice plants. Considering this, the unchanged infection phenotype for 9 gene deletions surprised us, and we extended the analysis to expression co-regulation of all 19 Myb proteins and found 5 co-regulated groups of predicted Myb-domain proteins. MoMyb13 or MoMyb15 are discussed and motivated as candidates for further, more detailed studies with aims also outside of plant pathology. Referring to what is found in other eukaryotes, we finally discuss possible redundancy or compensatory regulations for many of the other Myb genes hiding or compensating for the effect of many complete deletions. IMPORTANCEMagnaporthe oryzae is considered the most important rice pathogen limiting rice production. Our study attempts to find all genes encoding a DNA-binding gene family called Myb, and we found 19, many of which have not been studied before. The Myb gene family is suspected to regulate stress responses the pathogen needs to overcome plant defenses. Inhibiting or disturbing these genes, if they are indeed regulatory, can open new ways of controlling the pathogen and learning more about its physiology and ecology.

microbiology↗

bioRxiv2021

Global Mapping of Mouse CSF Flow via HEAP-METRIC Phase-contrast MRI

Roles of Cerebrospinal fluid (CSF) in brain waste clearance and homeostasis has been increasingly recognized, thus measuring its flow dynamics could provide important information about its function and perturbance. While phase-contrast MRI can be used for non-invasive flow mapping, so far its mapping of low velocity flow (such as mouse brain CSF) is not possible. Here we developed a novel generalized Hadamard encoding based multi-band acceleration scheme dubbed HEAP-METRIC (Hadamard Encoding APproach of Multi-band Excitation for short TR Imaging aCcelerating), and with significantly increased SNR per time, HEAP-METRIC phase-contrast MRI achieved fast and accurate mapping of slow (~102 micron/s) flow. Utilizing this novel method, we revealed a heterogeneous global pattern of CSF flow in the awake mouse brain with a averaged flow of ~200 micron/s, and further found isoflurane anesthesia reduced CSF flow that was accompanied by reduction of glymphatic function. Therefore, we developed the novel HEAP-METRIC phase-contrast MRI for mapping low velocity flow, and demonstrated its capability for global mapping of mouse CSF flow and its potential alterations related to various physiological or pathological conditions.

neuroscience↗

bioRxiv2020

C1q/CTRP1 exerts neuroprotective effects in TBI rats by regulating inflammation and autophagy

ObjectiveC1q/CTRP1 is a newly discovered adiponectin protein, which is highly expressed in adipose and heart tissues. Recent studies have revealed that C1q/CTRP1 can regulate metabolism and inhibit inflammation. CTRP1 is also expressed in brain tissues and vascular cells of human and rat, and research on cerebral hemorrhage and cerebral ischemia-reperfusion injury demonstrates that the CTRP family can attenuate secondary brain injury and exert neuroprotective effects. Thus, this study was designed to explore the role of CTRP1 in traumatic brain injury (TBI) and the underlying mechanism. Main methodsRats were assigned into rCTRP1 group, vehicle group, and sham group. Modified Feeneys method was used to establish a closed traumatic brain injury model. Morris water maze was used for directional navigation, reverse searching and space exploration tests in rats. In addition, Golgi-Cox staining was utilized to visualize neurons, dendrites and dendritic spines. ELISA was conducted to detect the levels of inflammatory factors (IL-6 and TNF-). Finally, Western blot was adopted to detect the relative expression of p-mTOR and autophagy-related proteins (Beclin-1 and LC3-II). ResultsCTRP1 improved the behavioral and histopathological outcomes, inhibited the inflammatory response, activated mTOR and decreased autophagy-associated protein synthesis in TBI rats. ConclusionCTRP1 exerts neuroprotective effects in TBI rats by regulating inflammation and autophagy and has potential therapeutic properties after TBI.

pathology↗