Pia-FLOW: Deciphering hemodynamic maps of the pial vascular connectome and its response to arterial occlusion.

The pial vasculature is the sole source of blood supply to the neocortex. The brain is contained within the skull, a vascularized bone marrow with a unique anatomical connection to the brain meninges. Recent developments in tissue clearing have enabled detailed mapping of the entire pial and calvarial vasculature. However, what are the absolute flow rate values of those vascular networks? This information cannot accurately be retrieved with the commonly used bioimaging methods. Here, we introduce Pia-FLOW, a unique approach based on large-scale transcranial fluorescence localization microscopy, to attain hemodynamic imaging of the whole murine pial and calvarial vasculature at frame rates up to 1,000 Hz and spatial resolution reaching 5.4 µm. Using Pia-FLOW, we provide detailed maps of flow velocity, direction, and vascular diameters which can serve as ground-truth data for further studies, advancing our understanding of brain fluid dynamics. Furthermore, Pia-FLOW revealed that the pial vascular network functions as one unit for robust allocation of blood after stroke.

Multimodal optoacoustic imaging: methods and contrast materials.

Optoacoustic (OA) imaging offers powerful capabilities for interrogating biological tissues with rich optical absorption contrast while maintaining high spatial resolution for deep tissue observations. The spectrally distinct absorption of visible and near-infrared photons by endogenous tissue chromophores facilitates extraction of diverse anatomic, functional, molecular, and metabolic information from living tissues across various scales, from organelles and cells to whole organs and organisms. The primarily blood-related contrast and limited penetration depth of OA imaging have fostered the development of multimodal approaches to fully exploit the unique advantages and complementarity of the method. We review the recent hybridization efforts, including multimodal combinations of OA with ultrasound, fluorescence, optical coherence tomography, Raman scattering microscopy and magnetic resonance imaging as well as ionizing methods, such as X-ray computed tomography, single-photon-emission computed tomography and positron emission tomography. Considering that most molecules absorb light across a broad range of the electromagnetic spectrum, the OA interrogations can be extended to a large number of exogenously administered small molecules, particulate agents, and genetically encoded labels. This unique property further makes contrast moieties used in other imaging modalities amenable for OA sensing.

Photosynthetic characteristics and genetic mapping of a new yellow leaf mutant crm1 in Brassica napus.

Chlorophyll is one of the key factors for photosynthesis and plays an important role in plant growth and development. We previously isolated an EMS mutagenized rapeseed chlorophyll-reduced mutant (crm1), which had yellow leaf, reduced chlorophyll content and fewer thylakoid stacks. Here, we found that crm1 showed attenuated utilization efficiency of both light energy and CO2 but enhanced heat dissipation efficiency and greater tolerance to high-light intensity. BSA-Seq analysis identified a single nucleotide change (C to T) and (G to A) in the third exon of the BnaA01G0094500ZS and BnaC01G0116100ZS, respectively. These two genes encode the magnesium chelatase subunit I 1 (CHLI1) that catalyzes the insertion of magnesium into protoporphyrin IX, a pivotal step in chlorophyll synthesis. The mutation sites resulted in an amino acid substitution P144S and G128E within the AAA+ domain of the CHLI1 protein. Two KASP markers were developed and co-segregated with the yellow leaf phenotype in segregating F2 population. Loss of BnaA01.CHLI1 and BnaC01.CHLI1 by CRISPR/Cas9 gene editing recapitulated the mutant phenotype. BnaA01.CHLI1 and BnaC01.CHLI1 were located in chloroplast and highly expressed in the leaves. Furthermore, RNA-seq analyses revealed the expression of chlorophyll synthesis-related genes were upregulated in the crm1 mutant. These findings provide a new insight into the regulatory mechanism of chlorophyll synthesis in rapeseed and suggest a novel target for improving the photosynthetic efficiency and tolerance to high-light intensity in crops. Supplementary Information: The online version contains supplementary material available at 10.1007/s11032-023-01429-6.

The effects of Shikonin on the hypertrophic scar of rabbit ears via the TLR4/NF-κB signaling pathway.

As a traditional Chinese medicine, Zihuang Shengji Ointment has obvious effects on promoting postoperative wound healing and reducing scar formation in clinical application. Shikonin is the major phytochemical in Zihuang Shengji Ointment. As a kind of naphquinone compound with anti-tumor, anti-viral, anti-inflammatory, anti-bacterial and other biological activities extracted from Lithospermum erythrorhizon, shikonin exerts an important role in many diseases. Shikonin has impacts on the development of hypertrophic scars (HS), however, these effects are yet mostly unknown. As a result, we created the Newland white rabbit ear HS model, administered shikonin to it, and then assessed scar hypertrophy using HE and VG staining. The degree of scarring is assessed by HI, NA, as well as AA. The expression levels of collagen I, collagen III, as well as α-SMA as well as fibroblast proliferation, are also measured using real-time PCR, immunohistochemistry, and western blot. TUNEL tests are used to assess fibroblast apoptosis. In our work, HE staining and VG staining showed that the shikonin-treated group had normal bundles of collagen fibers and regular fibroblasts. Shikonin suppresses the production of HS, according to histopathological features, HI, NA, and AA measures. Shikonin also causes fibroblast apoptosis and lowers the production of α-SMA, collagen I, as well as collagen III in the HS rat. Notably, we discover that NF-κB activation and TLR4 activity are inhibited by shikonin. Overall, the results show that the signaling pathway of TLR4/NF-κB is modulated by shikonin's inhibitory effect on scar formation, which represses the levels of collagen I, collagen III, α-SMA, as well as fibroblasts.

Drainage volume on postoperative day one to predict clinically relevant postoperative pancreatic fistula following distal pancreatectomy.

BACKGROUND: The purpose of this study was to determine how the drain fluid volume on the first day after surgery (DFV 1) can be used to predict clinically relevant post-operative pancreatic fistula following distal pancreatectomy (DP). METHOD: A retrospective analysis of 175 patients who underwent distal pancreatectomy in hepatobiliary surgery at Chengdu 363 Hospital (China) from January 2015 to January 2021 has been performed. Depending on the presence of pancreatic fistula, all patients were divided into two groups: POPF and non-POPF. The clinical factors were analyzed using SPSS 17.0 and Medcalc software. In order to assess the effectiveness of DFV 1 in predicting POPF after surgery, ROC curves were used to calculate its cut-off point,, which yielded sensitivity and negative predictive value of 100% for excluding POPF. RESULT: Of the 175 patients who underwent distal pancreatectomy, the incidence of overall pancreatic fistula was 36%, but the rate of clinically significant (grade B and C) fistula, as defined by the International Study Group on Pancreatic Fistula, 30 was only 17.1% (28 grade B and 2 grade C fistula). The results from univariate and multivariate logistic regression analysis showed that drain fluid volume on the first postoperative day (OR = 0.95, P = 0.03), drainage fluid amylase level on POD1 (OR = 0.99, P = 0.01) and the preoperative ALT level (OR = 0.73, P = 0.02) were independent risk factors associated with CR-POPF. Receiver operating characteristic (ROC) curve analysis revealed that a drainage volume of 156 mL within 24 h and an amylase greater than 3219.2 U/L on the first postoperative day were the optimal thresholds associated with complications. CONCLUSION: After distal pancreatectomy, the drainage volume on the first postoperative day can predict the presence of a clinically relevant pancreatic fistula.

Impact of COVID-19 Outbreak on the Long-Range Transport of Common Air Pollutants in KUWAMS.

As a background sampling site in western Japan, the Kanazawa University Wajima Air Monitoring Station (KUWAMS) continuously observes the air pollutants, including PM1, PM2.5, organic carbon (OC) and element carbon (EC). Data for September 2019 to April 2020 were compared with data for September 2018 to April 2019. The mean concentrations of both PM1 and PM2.5 were 4.10 µg/m3 (47%) and 5.82 µg/m3 (33%) lower, respectively in the Coronavirus Disease 2019 (COVID-19) period (January to April) than in the same period in 2019. Notably, the average concentrations of both classes of particulate matter (PM) in the COVID-19 period were the lowest for that period in all years since 2016. OC and EC also considerably lower (by 69 and 63%, respectively) during the COVID-19 period than during the same period in 2019. All pollutants were then started to increase after the resumption of the work in 2020. The pollutant variations correspond to the measure implemented during the COVID-19 period, including the nationwide lockdown and work resumption. Furthermore, the reductions in the ratios PM1/PM2.5 and OC/EC during COVID-19 period indicate lighter pollution and fewer emission sources. This analysis of the changes in the pollutant concentrations during the epidemic and non-epidemic periods illustrates the significance of the dominant pollution emissions at KUWAMS and the impact of pollution from China that undergoes long-range transport to KUWAMS.

Yearly variation in characteristics and health risk of polycyclic aromatic hydrocarbons and nitro-PAHs in urban shanghai from 2010-2018.

This study encompassed the regular observation of nine polycyclic aromatic hydrocarbons (PAHs) and three nitro-PAHs (NPAHs) in particulate matter (PM) in Shanghai in summer and winter from 2010 to 2018. The results showed that the mean concentrations of Æ©PAHs in summer decreased by 24.7% in 2013 and 18.1% in 2017 but increased by 10.2% in 2015 compared to the data in 2010. However, the mean concentrations of Æ©PAHs in winter decreased by 39.7% from 2010 (12.8 ± 4.55 ng/m3) to 2018 (7.72 ± 3.33 ng/m3), and the mean concentrations of 1-nitropyrene in winter decreased by 79.0% from 2010 (42.3 ± 16.1 pg/m3) to 2018 (8.90 ± 2.09 pg/m3). Correlation analysis with meteorological conditions revealed that the PAH and NPAH concentrations were both influenced by ambient temperature. The diagnostic ratios of PAHs and factor analysis showed that they were mainly affected by traffic emissions with some coal and/or biomass combustion. The ratio of 2-nitrofluoranthene to 2-nitropyrene was near 10, which indicated that the OH radical-initiated reaction was the main pathway leading to their secondary formation. Moreover, backward trajectories revealed different air mass routes in each sampling period, indicating a high possibility of source effects from the northern area in winter in addition to local and surrounding influences. Meanwhile, the mean total benzo[a]pyrene-equivalent concentrations in Shanghai in winter decreased by 50.8% from 2010 (1860 ± 645 pg/m3) to 2018 (916 ± 363 pg/m3). These results indicated the positive effects of the various policies and regulations issued by Chinese authorities.

Widefield fluorescence localization microscopy for transcranial imaging of cortical perfusion with capillary resolution.

Imaging of cerebral vasculature is impeded with the existing fluorescence microscopy methods due to intense light scattering in living tissues and the need for highly invasive craniotomy procedures to resolve structures on a capillary scale. We propose a widefield fluorescence localization microscopy technique for high-resolution transcranial imaging and quantitative assessment of cortical perfusion in mice. The method is based on tracking single fluorescent microparticles sparsely distributed in the blood stream using a simple CMOS camera and a continuous-wave laser source. We demonstrate quantitative transcranial in vivo mapping of the blood flow velocity and direction at capillary level resolution (5 µm) across the entire cortex. The new technique opens a new high-resolution transcranial window into the brain function in health and disease.

The predictive value of procalcitonin for postoperative early pancreatic fistula.

BACKGROUND: To investigate the early prediction value of procalcitonin (PCT) in pancreatic fistula (POPF) after pancreatoduodenectomy (PD). METHOD: Retrospective analysis of clinical data of 67 patients undergoing pancreaticoduodenectomy (PD) and 19 patients undergoing distalpancreatectomy (DP) were performed in the Department of Hepatobiliary Surgery, Leshan People's Hospital from January 2017 to December 2018. All patients were divided into POPF group and non-POPF group depending on the presence of pancreatic fistula. And fistulas were classified according to the ISGPF classification scheme. Plasma PCT levels, serum CRP concentration, and WBC counts were assessed preoperatively and on postoperative days (PODs) 1, 3, and 5. Statistical analyses were performed with statistical software. The ROC curve was used to analyze the efficacy of PCT and CRP in POPF prediction after surgery and determine their Cut-off value. RESULT: There were no statistically significant differences identified in age, gender, BMI, diabetes, abdominal surgery history, preoperative laboratory data, operation time, intraoperative bleeding volume, tumor nature and medical expenses of PD patients between the two groups (P > 0.05). While the incidence of postoperative hyperglycemia, postoperative ICU rate and postoperative hospital stay were statistically significant (P < 0.05). The AUC for PCT diagnosis of pancreatic fistula 1 day after surgery was 0.77 (95% CI: 0.675 ~ 0.860). Compared with CRP [0.53 (95% CI: 0.420 ~ 0.639)] and WBC [0.60 (95% CI: 0.490 ~ 0.705)], the optimal cut-off value (cut-off) was 0.67 µg/L. At this time, the sensitivity and specificity of detecting pancreatic fistula were 73.68 and 76.12%, respectively. The results at 3 days after surgery were similar to those at 5 days after surgery. And DP patients had similar results as PD patients. CONCLUSION: The PCT is valuable for early prediction of pancreatic fistula after Pancreaticoduodenectomy.

Size distribution of particulate polycyclic aromatic hydrocarbons in fresh combustion smoke and ambient air: A review.

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous in the atmosphere and they mostly stem from the imperfect combustion of fossil fuels and biofuels. PAHs are inherently associated with homogenous fine particles or distributed to different-sized particles during the aging of air masses. PAHs carried by fine particles undergo a long-range transport to remote areas while those adsorbed on coarse particles have a shorter lifetime in ambient air. More importantly, PAHs with higher molecular weights tend to be bound with finer particles and can deeply enter the lungs, posing severe health risks to humans. Thus, the environmental fate and health effects of particulate PAHs are strongly size-dependent. This review summarizes the size distributions of particulate PAHs freshly emitted from combustion sources as well as the distribution patterns of PAHs in ambient particles. It was found that PAHs from stationary sources are primarily bound to fine particles, which are slightly larger than particles to which PAHs from mobile sources are bound. In ambient air, particulate PAHs are distributed in larger size modes than those in the combustion fume, and the particle size decreases with PAH molecular weight increasing. The relevant mechanisms and influencing factors of particle size distribution changes are illustrated in this article, which are essentially attributed to combustion and ambient temperature as well as the physical and chemical properties of PAHs. Overall, the study on the particle size distribution of PAHs will contribute for a full understanding of the origin, atmospheric behaviors and health effects of particulate PAHs.

Monitoring circulating tumor cells in vivo by a confocal microscopy system.

Circulating tumor cells (CTCs) play a key role in cancer metastasis but are very difficult to detect. in vivo monitoring CTCs has been recognized as an important technique for cancer research and clinical diagnosis. Recently, a noninvasive method, in vivo flow cytometry (IVFC) has been developed to enable continuous, real-time, and long-duration detection of CTCs in animal models by detecting CTC fluorescence in blood vessels excited by lasers. In this study, we present a simple optical scheme for direct noninvasive CTC detection using confocal microscopes. We demonstrate that line scanning of confocal microscopy can provide effective and quantitative CTC detection in live mice during cancer development. Rare CTC signals can be acquired at the early stage of the tumor development after implantation of subcutaneous tumor and monitored continuously to the end. Signals from CTC clusters can also be acquired and distinguished from single CTCs. Our results suggest confocal microscopy is a simple and reliable method for biologists and doctors to use for cancer research. © 2018 International Society for Advancement of Cytometry.

Assessement of postoperative long-term survival quality and complications associated with radical antegrade modular pancreatosplenectomy and distal pancreatectomy: a meta-analysis and systematic review.

BACKGROUND: This study evaluated the perioperative complications and the long-term pancreatic survival outcomes in patients treated with radical antegrade modular pancreatosplenectomy (RAMPS) and distal pancreatectomy (DP). METHOD: We performed a computer search on the PubMed, Embase and Cochrane Library databases to retrieve the RCT or clinical trials comparing RAMPS and DP published before July of 2018. The quality of the included trials was assessed according to the inclusion and exclusion criteria by two researchers independently. The RevMan 5.3 software was used to extract and analyze the data. RESULT: A total of 5 retroprospective clinical trial articles comprising 285 patients were included in the study. The number of patients who underwent RAMPS were 135 and 150 for DP. There were significant differences (P < 0.05) in the operation time [WMD = - 63.93, 95% CI (- 68.86 ~ - 58.99), P<0.00001], and bleeding volume [WMD = - 184.62, 95% CI (- 211.88 ~ - 157.37), P<0.00001] between the two groups. However, no significant differences were observed between RAMPS and DP in terms of pancreatic fistula, postoperative complications, postoperative hospital stay, and mortality (P>0. 05). As for pathological examination, there were statistically significant differences between RAMPS and DP in the R0 resection rate [RR = 2.37, 95% CI (1.19 ~ 4.72), P = 0.01] and the number of lymph node excision [WMD = 7.08, 95% CI (4.59 ~ 9.58), P<0.000013]. The one-year overall survival rate was higher in RAMPS patients compared to DP patients [RR = 1.20, 95% CI (1.02 ~ 1.41), P = 0.02]. But there were no significant difference in postoperative recurrence [RR = 0.85, 95% CI (0.70 ~ 1.04), P = 0.13] between the two groups. CONCLUSION: RAMPS is an effective procedure for clinical application. Nevertheless, large, multicenter prospective randomized controlled trias are required to validate these findings. CONCLUSION: The RAMPS procedure was associated with good postoperative outcomes and overall survival, indicating that it is an effective procedure for clinical application. Large, multicenter prospective randomized controlled trials are needed to validate these findings.

Cortex-wide transcranial localization microscopy with fluorescently labeled red blood cells.

Large-scale imaging of brain activity with high spatio-temporal resolution is crucial for advancing our understanding of brain function. The existing neuroimaging techniques are largely limited by restricted field of view, slow imaging speed, or otherwise do not have the adequate spatial resolution to capture brain activities on a capillary and cellular level. To address these limitations, we introduce fluorescence localization microscopy aided with sparsely-labeled red blood cells for cortex-wide morphological and functional cerebral angiography with 4.9 µm spatial resolution and 1 s temporal resolution. When combined with fluorescence calcium imaging, the proposed method enables extended recordings of stimulus-evoked neuro-vascular changes in the murine brain while providing simultaneous multiparametric readings of intracellular neuronal activity, blood flow velocity/direction/volume, and vessel diameter. Owing to its simplicity and versatility, the proposed approach will become an invaluable tool for deciphering the regulation of cortical microcirculation and neurovascular coupling in health and disease.

The PHYB-FOF2-VOZ2 module functions to fine-tune flowering in response to changes in light quality by modulating FLC expression in Arabidopsis.

Proper timing of flowering under different environmental conditions is critical for plant propagation. Light quality is a pivotal environmental cue that plays a critical role in flowering regulation. Plants tend to flower late under light with a high red (R)/far-red (FR) light ratio but early under light with a low R/FR light ratio. However, how plants fine-tune flowering in response to changes in light quality is not well understood. Here, we demonstrate that F-box of Flowering 2 (FOF2), an autonomous pathway-related regulator, physically interacts with VASCULAR PLANT ONE-ZINC FINGER 1 and 2 (VOZ1 and VOZ2), which are direct downstream factors of the R/FR light receptor phytochrome B (PHYB). We show that PHYB physically interacts with FOF2, mediates stabilization of the FOF2 protein under FR light and end-of-day FR light, and enhances FOF2 binding to VOZ2, which leads to degradation of VOZ2 by SCFFOF2 E3 ligase. By contrast, PHYB mediates degradation of FOF2 protein under R light and end-of-day R light. Genetic interaction studies demonstrated that FOF2 functions downstream of PHYB to promote FLC expression and inhibit flowering under both high R/FR light and simulated shade conditions, processes that are partially dependent on VOZ proteins. Taken together, our findings suggest a novel mechanism whereby plants fine-tune flowering time through a PHYB-FOF2-VOZ2 module that modulates FLC expression in response to changes in light quality.

Deep optoacoustic localization microangiography of ischemic stroke in mice.

Super-resolution optoacoustic imaging of microvascular structures deep in mammalian tissues has so far been impeded by strong absorption from densely-packed red blood cells. Here we devised 5 µm biocompatible dichloromethane-based microdroplets exhibiting several orders of magnitude higher optical absorption than red blood cells at near-infrared wavelengths, thus enabling single-particle detection in vivo. We demonstrate non-invasive three-dimensional microangiography of the mouse brain beyond the acoustic diffraction limit (<20 µm resolution). Blood flow velocity quantification in microvascular networks and light fluence mapping was also accomplished. In mice affected by acute ischemic stroke, the multi-parametric multi-scale observations enabled by super-resolution and spectroscopic optoacoustic imaging revealed significant differences in microvascular density, flow and oxygen saturation in ipsi- and contra-lateral brain hemispheres. Given the sensitivity of optoacoustics to functional, metabolic and molecular events in living tissues, the new approach paves the way for non-invasive microscopic observations with unrivaled resolution, contrast and speed.

Advanced flow cytometry for biomedical applications.

Flow cytometry (FC) is a versatile tool with excellent capabilities to detect and measure multiple characteristics of a population of cells or particles. Notable advancements in in vivo photoacoustic FC, coherent Raman FC, microfluidic FC, and so on, have been achieved in the last two decades, which endows FC with new functions and expands its applications in basic research and clinical practice. Advanced FC broadens the tools available to researchers to conduct research involving cancer detection, microbiology (COVID-19, HIV, bacteria, etc.), and nucleic acid analysis. This review presents an overall picture of advanced flow cytometers and provides not only a clear understanding of their mechanisms but also new insights into their practical applications. We identify the latest trends in this area and aim to raise awareness of advanced techniques of FC. We hope this review expands the applications of FC and accelerates its clinical translation.

Three-dimensional wide-field fluorescence microscopy for transcranial mapping of cortical microcirculation.

Wide-field fluorescence imaging is an indispensable tool for studying large-scale biodynamics. Limited space-bandwidth product and strong light diffusion make conventional implementations incapable of high-resolution mapping of fluorescence biodistribution in three dimensions. We introduce a volumetric wide-field fluorescence microscopy based on optical astigmatism combined with fluorescence source localization, covering 5.6×5.6×0.6 mm3 imaging volume. Two alternative configurations are proposed exploiting multifocal illumination or sparse localization of point emitters, which are herein seamlessly integrated in one system. We demonstrate real-time volumetric mapping of the murine cortical microcirculation at capillary resolution without employing cranial windows, thus simultaneously delivering quantitative perfusion information across both brain hemispheres. Morphological and functional changes of cerebral vascular networks are further investigated after an acute ischemic stroke, enabling cortex-wide observation of concurrent collateral recruitment events occurring on a sub-second scale. The reported technique thus offers a wealth of unmatched possibilities for non- or minimally invasive imaging of biodynamics across scales.

Depth-Resolved Localization Microangiography in the NIR-II Window.

Detailed characterization of microvascular alterations requires high-resolution 3D imaging methods capable of providing both morphological and functional information. Existing optical microscopy tools are routinely used for microangiography, yet offer suboptimal trade-offs between the achievable field of view and spatial resolution with the intense light scattering in biological tissues further limiting the achievable penetration depth. Herein, a new approach for volumetric deep-tissue microangiography based on stereovision combined with super-resolution localization imaging is introduced that overcomes the spatial resolution limits imposed by light diffusion and optical diffraction in wide-field imaging configurations. The method capitalizes on localization and tracking of flowing fluorescent particles in the second near-infrared window (NIR-II, ≈1000-1700 nm), with the third (depth) dimension added by triangulation and stereo-matching of images acquired with two short-wave infrared cameras operating in a dual-view mode. The 3D imaging capability enabled with the proposed method facilitates a detailed visualization of microvascular networks and an accurate blood flow quantification. Experiments performed in tissue-mimicking phantoms demonstrate that high resolution is preserved up to a depth of 4 mm in a turbid medium. Transcranial microangiography of the entire murine cortex and penetrating vessels is further demonstrated at capillary level resolution.

Multimodal Noninvasive Functional Neurophotonic Imaging of Murine Brain-Wide Sensory Responses.

Modern optical neuroimaging approaches are expanding the ability to elucidate complex brain function. Diverse imaging contrasts enable direct observation of neural activity with functional sensors along with the induced hemodynamic responses. To date, decoupling the complex interplay of neurovascular coupling and dynamical physiological states has remained challenging when employing single-modality functional neuroimaging readings. A hybrid fluorescence optoacoustic tomography platform combined with a custom data processing pipeline based on statistical parametric mapping is devised, attaining the first noninvasive observation of simultaneous calcium and hemodynamic activation patterns using optical contrasts. Correlated changes in the oxy- and deoxygenated hemoglobin, total hemoglobin, oxygen saturation, and rapid GCaMP6f fluorescence signals are observed in response to peripheral sensory stimulation. While the concurrent epifluorescence serves to corroborate and complement the functional optoacoustic observations, the latter further aids in decoupling the rapid calcium responses from the slowly varying background in the fluorescence recordings mediated by hemodynamic changes. The hybrid imaging platform expands the capabilities of conventional neuroimaging methods to provide more comprehensive functional readings for studying neurovascular and neurometabolic coupling mechanisms and related diseases.

Multiscale optical and optoacoustic imaging of amyloid-ß deposits in mice.

Deposits of amyloid-ß (Aß) in the brains of rodents can be analysed by invasive intravital microscopy on a submillimetre scale, or via whole-brain images from modalities lacking the resolution or molecular specificity to accurately characterize Aß pathologies. Here we show that large-field multifocal illumination fluorescence microscopy and panoramic volumetric multispectral optoacoustic tomography can be combined to longitudinally assess Aß deposits in transgenic mouse models of Alzheimer's disease. We used fluorescent Aß-targeted probes (the luminescent conjugated oligothiophene HS-169 and the oxazine-derivative AOI987) to transcranially detect Aß deposits in the cortex of APP/PS1 and arcAß mice with single-plaque resolution (8 µm) and across the whole brain (including the hippocampus and the thalamus, which are inaccessible by conventional intravital microscopy) at sub-150 µm resolutions. Two-photon microscopy, light-sheet microscopy and immunohistochemistry of brain-tissue sections confirmed the specificity and regional distributions of the deposits. High-resolution multiscale optical and optoacoustic imaging of Aß deposits across the entire brain in rodents thus facilitates the in vivo study of Aß accumulation by brain region and by animal age and strain.