Biology subjects

Zhang, T.

Publications and source records attributed to Zhang, T..

At least 577 records · Page 32Linked to original sources

bioRxiv2019

Longitudinal bioluminescent imaging of HIV-1 infection during antiretroviral therapy and treatment interruption in humanized mice

Non-invasive bioluminescent imaging (NIBLI) of HIV-1 infection dynamics allows for real-time monitoring of viral spread and the localization of infected cell populations in living animals. In this report, we describe full-length replication-competent GFP and Nanoluciferase (Nluc) expressing HIV-1 reporter viruses from two clinical transmitted / founder (T/F) stains: TRJO.c and Q23.BG505. By infecting humanized mice with these HIV-1 T/F reporter viruses, we were able to directly monitor longitudinal viral spread at whole-animal resolution via NIBLI at a sensitivity of as few as 30-50 infected cells. Bioluminescent signal strongly correlated with HIV-1 infection and responded proportionally to virus suppression in vivo in animals treated daily with a combination antiretroviral therapy (cART) regimen. Longitudinal NIBLI following cART withdrawal visualized tissue-sites that harbored virus during infection recrudescence. Notably, we observed rebounding infection in the same lymphoid tissues where infection was first observed prior to ART treatment. Our work demonstrates the utility of our system for studying in vivo viral infection dynamics and identifying infected tissue regions for subsequent analyses.\n\nAuthor SummaryNon-invasive bioluminescent imaging (NIBLI) in small animals allows for in vivo longitudinal imaging of infection spread and pathogenesis. We have taken advantage of the small luciferase reporter protein, Nanoluciferase (Nluc), to generate a replication-competent HIV-1 reporter virus to allow for NIBLI of viral infection in humanize mice. NIBLI via Nluc enabled us to directly visualize longitudinal spreading patterns before, during, and after interruption of daily doses of combined antiretroviral therapy (cART). We observed that rebounding infection often emerged in tissue regions originally associated with infected cells prior to cART treatment. Thus, Nluc-based NIBLI of HIV-1 infection can be used as an experimental tool to study early events involved in viral dissemination and spread from initial sites of infection to draining lymphoid tissues as well as locate infected tissues for subsequent cellular characterization of HIV-1 infected cells.

microbiology↗

bioRxiv2019

Deep Learning-Based Point-Scanning Super-Resolution Imaging

Point scanning imaging systems (e.g. scanning electron or laser scanning confocal microscopes) are perhaps the most widely used tools for high resolution cellular and tissue imaging. Like all other imaging modalities, the resolution, speed, sample preservation, and signal-to-noise ratio (SNR) of point scanning systems are difficult to optimize simultaneously. In particular, point scanning systems are uniquely constrained by an inverse relationship between imaging speed and pixel resolution. Here we show these limitations can be mitigated via the use of deep learning-based super-sampling of undersampled images acquired on a point-scanning system, which we termed point-scanning super-resolution (PSSR) imaging. Oversampled, high SNR ground truth images acquired on scanning electron or Airyscan laser scanning confocal microscopes were crappified to generate semi-synthetic training data for PSSR models that were then used to restore real-world undersampled images. Remarkably, our EM PSSR model could restore undersampled images acquired with different optics, detectors, samples, or sample preparation methods in other labs. PSSR enabled previously unattainable 2 nm resolution images with our serial block face scanning electron microscope system. For fluorescence, we show that undersampled confocal images combined with a multiframe PSSR model trained on Airyscan timelapses facilitates Airyscan-equivalent spatial resolution and SNR with [~]100x lower laser dose and 16x higher frame rates than corresponding high-resolution acquisitions. In conclusion, PSSR facilitates point-scanning image acquisition with otherwise unattainable resolution, speed, and sensitivity.\n\n\n\nO_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=116 SRC=\"FIGDIR/small/740548v8_ufig1.gif\" ALT=\"Figure 1\">\nView larger version (90K):\norg.highwire.dtl.DTLVardef@fbf19aorg.highwire.dtl.DTLVardef@b2cc88org.highwire.dtl.DTLVardef@921e1corg.highwire.dtl.DTLVardef@f6c5af_HPS_FORMAT_FIGEXP M_FIG C_FIG

bioinformatics↗

bioRxiv2019

Effects of Shift-Work on the Carotid Artery and Cerebral Blood Flow of SHR Rats and WKY Rats

ObjectiveThe objective was to investigate the effects of shift-work (SW) on the carotid arteries.\n\nMethodsThis study used two inverted photoperiods (inverted light:dark [ILD]16:8 and ILD12:12) to create the SW model. We recorded the rhythm and performed serological tests, carotid ultrasound, magnetic resonance imaging, and carotid biopsy.\n\nResultsSW induced elevated blood pressure and increased angiotensin-II, apolipoprotein E, blood glucose, and triglycerides. SW increased the carotid intima-media thickness. SW led to the development of carotid arterial thrombosis, reduced cerebral blood flow, and increased the number of collagen fibers, expression of angiotensin receptor and low-density lipoprotein receptor in the carotid arteries. SW decreased 3-hydroxy-3-methylglutaryl-CoA reductase and nitric oxide. SW induced the atherosclerotic plaque in the aorta. Multiple results of SHR were worse than WKY rats.\n\nConclusionSW can induce metabolic disorders and elevated blood pressure. SW can cause intima-media thickening of the carotid artery and aorta atherosclerosis. SW may result in carotid arterial thrombosis and affect cerebral blood flow. Hypertension can aggravate the adverse effects of SW.

pathology↗

bioRxiv2019

Structural complementarity facilitates E7820-mediated degradation of RBM39 by DCAF15

The investigational drugs E7820, indisulam and tasisulam (aryl-sulfonamides) promote the degradation of the splicing factor RBM39 in a proteasome-dependent mechanism. While the activity critically depends on the Cullin RING ligase substrate receptor DCAF15, the molecular details remain elusive. Here we present the cryo-EM structure of the DDB1-DCAF15-DDA1 core ligase complex bound to RBM39 and E7820 at 4.4 [A] resolution, together with crystal structures of engineered subcomplexes. We show that DCAF15 adopts a novel fold stabilized by DDA1, and that extensive protein-protein contacts between the ligase and substrate mitigate low affinity interactions between aryl-sulfonamides and DCAF15. Our data demonstrates how aryl-sulfonamides neo-functionalize a shallow, non-conserved pocket on DCAF15 to selectively bind and degrade RBM39 and the closely related splicing factor RBM23 without the requirement for a high affinity ligand, which has broad implications for the de novo discovery of molecular glue degraders.

biochemistry↗

bioRxiv2019

M-GWAS for the gut microbiome in Chinese adults illuminates on complex diseases

The gut microbiome has been established as a key environmental factor to health. Genetic influences on the gut microbiome have been reported, yet, doubts remain as to the significance of genetic associations. Here, we provide shotgun data for whole genome and whole metagenome from a Chinese cohort, identifying no less than 20% genetic contribution to the gut microbiota. Using common variants-, rare variants- and copy number variations (CNVs)-based association analyses, we identified abundant signals associated with the gut microbiome especially in metabolic, neurological and immunological functions. The controversial concept of enterotypes may have a genetic attribute, with the top 2 loci explaining 11% of the Prevotella-Bacteroides variances. Stratification according to gender led to the identification of differential associations in males and females. Genetically encoded responses to ectopic presence of oral bacteria in the gut appear to be a common theme in a number of diseases investigated by MWAS (Metagenome-wide association studies). Our two-stage M-GWAS (Microbiome genome-wide association studies) on a total of 1295 individuals unequivocally illustrates that neither microbiome nor GWAS studies could overlook one another in our quest for a better understanding of human health and diseases.\n\nHighlightsM-GWAS using high-depth whole genome identifies contributions from rare variants and CNVs.\n\nGut microbial modules such as butyrate, amino acids, mucin degradation show genetic associations.\n\nGender differential M-GWAS underscores differences in metabolic and psychological predispositions.\n\nSome of the MWAS markers for colorectal cancer and cardiometabolic diseases show genetic associations.

genetics↗

bioRxiv2019

Auxin-induced nanoclustering of membrane signaling complexes underlies cell polarity establishment in Arabidopsis

Cell polarity is fundamental to the development of both eukaryotic and prokaryotic organisms, yet the mechanism of its establishment remains poorly understood. Here we show that signal-activated nanoclustering of membrane proteins and a cytoskeleton-based feedback loop provide an important mechanism for the establishment of cell polarity. The phytohormone auxin promoted sterol-dependent nanoclustering of cell surface transmembrane receptor-like kinase 1 (TMK1) to initiate cell polarity during the morphogenesis of Arabidopsis puzzle piece-shaped leaf pavement cells (PC). Auxin-triggered nanoclustering of TMK1 stabilized flotillin-associated ordered nanodomains, which were essential for auxin-mediated formation of ROP6 GTPase nanoclusters that act downstream TMK1 to promote cortical microtubule ordering. Mathematical modeling further demonstrated the essential role of this auxin-mediated stabilization of TMK1 and ROP6 nanoclusters, and predicted the additional requirement of ROP6-dependent cortical microtubules for further stabilization of TMK1-sterol nanodomains and the polarization of PC. This prediction was experimentally validated by genetic and biochemical data. Our studies reveal a new paradigm for polarity establishment: A diffusive signal triggers cell polarization by activating cell surface receptor-mediated lateral segregation of signaling components and a cytoskeleton-mediated positive feedback loop of nanodomain stabilization.\n\nHighlightsO_LISterols are required for cell polarity in Arabidopsis leaf epidermal cells\nC_LIO_LIAuxin promotes lipid ordering and polar distribution of ordered lipid nanodomains at the plasma membrane (PM)\nC_LIO_LIAuxin stabilizes sterol-dependent nanoclustering of transmembrane kinase (TMK1), a PM auxin signal transducer\nC_LIO_LIAuxin-induced TMK1 nanoclustering is required but insufficient for cell polarization\nC_LIO_LIMicrotubule-based feedback stabilization of the auxin-induced TMK1 nanodomains can generate cell polarity\nC_LI

cell biology↗

bioRxiv2019

Megaloneurite, a giant neurite of vasoactive intestinal peptide and nitric oxide synthase in the aged dog and identification by human sacral spinal cord

Megaloneurite of NADPH diaphorase (NADPH-d) positivity is a new kind of aging-related neurodegeneration and also co-localized with vasoactive intestinal peptide (VIP) in the sacral spinal cord of aged dog and monkey. However, no immunocytochemistry of VIP was exclusively tested in the aged dog and no evidence has been reported in the aged human spinal cord. Aged dogs were used to examine the distribution of VIP immunopositivity in the sacral spinal cord. Immunocytochemistry of VIP and alpha-synuclein were also examined in the aged human spinal cord. The VIP immunopositivity in aged dog was reconfirmed our previous finding illustrated by immunofluorescent study. Megalogneurite was also identified by nitric oxide synthase (NOS) immunoreaction in aged dog. The VIP positive megaloneurites both in age dog and human were detected in dorsal root entry zoon, Lissauers tract, dorsal commissural nucleus and anterior commissural gray as well as in the lateral funiculus of the sacral spinal cord exclusive of other segments of spinal cord. Alpha-synuclein positivity was present mini-aggregation and Lewy body in the sacral spinal cord of aged human, that also occurred in the lumber, thoracic and cervical spinal cord. It was firstly tested that VIP megaloneurites occurred in the aged human sacral spinal cord, especially in the white matter. Megaloneurites identified by NADPH-d-VIP-NOS immunoreaction could implicate for the dysfunction of pelvic organs in the aged human being.

neuroscience↗

bioRxiv2019

REAVER: Improved Analysis of High-resolution Vascular Network Images Revealed Through Round-robin Rankings of Accuracy and Precision

Alterations in vascular networks, including angiogenesis and capillary regression, play key roles in disease, wound healing, and development. Imaging of microvascular networks can reveal their spatial structures, but effective study of network architecture requires methods to accurately quantify them using a variety of metrics. We present REAVER (Rapid Editable Analysis of Vessel Elements Routine), a freely available open source tool that researchers can use to analyze and quantify high resolution fluorescent images of blood vessel networks, and assess its performance compared to alternative state-of-the-art image analysis software programs. Top performing programs for each metric are identified by assigning a rank based on statistical multiple comparisons of accuracy and precision, modeled as matches in a round-robin style tournament. This comparison method yields a clearly defined and consistent standard for characterizing program performance, avoiding the use of non-standard ad hoc interpretations of multiple comparisons between programs. Using this comparison method and a dataset of manually analyzed images as a ground-truth, we show that REAVER was the top ranked program for both accuracy and precision for all metrics quantified, including vessel length density, vessel area fraction, mean vessel diameter, and branchpoint count. REAVER can be used to quantify differences in blood vessel architectures between study groups, which makes it particularly useful in experiments designed to evaluate the effects of different external perturbations (e.g. drugs or disease states).

bioinformatics↗

bioRxiv2019

The methodological quality of animal studies: A cross-sectional study based on the SYRCLEs risk of bias tool

ObjectiveTo assess the methodological quality of animal studies published in China and abroad using the SYRCLEs risk of bias tool, and to provide references to improve the methodological quality of animal studies to encourage high quality preclinical studies.\n\nMethodsAn electronic search was performed in the Chinese Scientific Citation Database (CSCD) and Web of Science from 2014 to October 2018. Document screening and data extraction were performed independently by four researchers. The methodological quality of the included studies was assessed using the SYRCLEs risk of bias tool. Statistical analysis was performed using SPSS23.\n\nResultsA total of 2764 animal studies were included. Of the studies, 984 were published in English and 1780 were in Chinese. The citation frequency of more than 90% of the included studies was less than 5. The results of methodological quality assessment showed that 36.36% (8/22) of the sub-items were rated as \"low risk\" in more than 50% of the included studies, of which 75% (6/8) were rated as \"low risk\" in more than 80% of the included studies. A total of 59.09% (13/22) of the sub-items were rated as \"low risk\" in less than 30% of the included studies, of which 92.31% (12/13) were rated as \"low risk\" in less than 10% of the included studies. The incidence of \"low risk\" Chinese studies regarding performance bias, detection bias and reporting bias were lower than English studies. For foreign studies, more attention should be paid to selection bias, attrition bias, and reporting bias.\n\nConclusionWe identified limitations in the methodological quality of animal experiment studies published in China and abroad. We therefore suggest that it is necessary to take targeted measures to popularize the SYRCLEs risk of bias tool to effectively improve the design and implementation of animal experiments, and guide study development.

scientific communication and education↗

bioRxiv2019

CELLULOSE SYNTHASE INTERACTIVE1- and Microtubule-Dependent Cell Wall Architecture Is Required for Acid Growth in Arabidopsis Hypocotyls

Auxin-induced cell elongation relies in part on the acidification of the cell wall, a process known as acid growth that presumably triggers expansin-mediated wall loosening via altered interactions between cellulose microfibrils. Cellulose microfibrils are a major determinant for anisotropic growth and they provide the scaffold for cell wall assembly. Little is known about how acid growth depends on cell wall architecture. To explore the relationship between acid growth-mediated cell elongation and plant cell wall architecture, two mutants (jia1-1 and csi1-3) that are defective in cellulose biosynthesis and cellulose microfibril organization were analyzed. The study revealed that cell elongation is dependent on CSI1-mediated cell wall architecture but not on the overall crystalline cellulose content. We observed a correlation between loss of crossed-polylamellate walls and loss of auxin- and fusicoccin-induced cell growth in csi1-3. Furthermore, induced loss of crossed-polylamellate walls via disruption of cortical microtubule mimics the effect of csi1 in acid growth. We hypothesize that CSI1- and microtubule-dependent crossed-polylamellate walls are required for acid growth in Arabidopsis hypocotyls.

plant biology↗

bioRxiv2019

Loci specific epigenetic drug sensitivity

Therapeutic targeting of epigenetic modulators offers a novel approach to the treatment of several diseases including cancer, heart diseases and AIDS. The cellular consequences of chemical compounds that target epigenetic regulators (epi-drugs) are complex. Epi-drugs affect global cellular phenotypes and cause local changes to gene expression due to alteration of a gene chromatin environment. Despite increasing use in the clinic, the mechanisms responsible for cellular changes are unclear. Specifically, to what degree the effects are a result of cell-wide changes or disease related locus specific effects is unknown. Here we developed a platform to systematically and simultaneously investigate the sensitivity of epi-drugs at hundreds of genomic locations by combining DNA barcoding, unique split-pool encoding and single cell expression measurements. Internal controls are used to isolate locus specific effects separately from any global consequences these drugs have. Using this platform we discovered wide-spread loci specific sensitivities to epi-drugs for three distinct epi-drugs that target histone deacetylase, DNA methylation and bromodomain proteins. By leveraging ENCODE data on chromatin modification, we identified features of chromatin environments that are most likely to be affected by epi-drugs. The measurements of loci specific epi-drugs sensitivities will pave the way to the development of targeted therapy for personalized medicine.

genomics↗

bioRxiv2019

Shotgun Metagenomics of 361 elderly women reveals gut microbiome change in bone mass loss

Bone mass loss contributes to the risk of bone fracture in the elderly. Many factors including age, obesity, estrogen and diet, are associated with bone mass loss. Mice studies suggest that the intestinal microbiome might influence the bone mass by regulating the immune system, however there has been little evidence from human studies. We have recruited 361 Chinese elderly women to collect data for a metagenomic-wide association study (MWAS) to investigate the influence of the gut microbiome on bone health. Gut microbiome data were produced using BGISEQ500 sequencing, BMD was calculated using Hologic dual energy X-ray machine, BMI (Body Mass Index) and age were also provided. This therefore data allows exploration of gut microbiome diversity and links to bone mass loss, as well as microbial species and modules as markers for bone mineral density. Making these data potentially useful in studying the role the gut microbiota might play in bone mass loss and offering exploration into the bone mass loss process.

microbiology↗

bioRxiv2019

Accurate inference of the full base-pairing structure of RNA by deep mutational scanning and covariation-induced deviation of activity

Despite the transcription of noncoding RNAs in 75% of the human genome and their roles in many diseases include cancer, we know very little about them due to lack of structural clues. The centerpiece of the structural clues is the full RNA base-pairing structure of secondary and tertiary contacts that can be precisely obtained only from costly and inefficient 3D structure determination. Here, we performed deep mutational scanning of self-cleaving CPEB3 ribozyme by error-prone PCR and showed that a library of <5x104 single-to-triple mutants is sufficient to infer all 26 including nonhelical and noncanonical base pairs at the precision of a single false positive. The accurate inference, further confirmed by a twister ribozyme, is resulted from covariation analysis by utilizing both functional and nonfunctional variants for unsupervised learning, followed by restrained optimization. The result highlights the usefulness of deep mutational scanning for high-accuracy structural inference.

molecular biology↗

bioRxiv2019

Assembly properties of FtsZ from cyanobacterium Synechocystis sp. PCC 6803

Tubulin homologue FtsZ is the major cytoskeletal protein in the bacterial cell division machinery. Here, we studied the biochemical and assembly properties of SyFtsZ, FtsZ from cyanobacterium Synechocystis sp. PCC 6803. SyFtsZ had a slow GTPase activity of around 0.4 GTP per FtsZ per minute and assembled into thick, straight protofilament bundles and curved bundles designated toroids. The assembly of SyFtsZ in the presence of GTP occurred in two stages. The first stage was assembled into single straight protofilaments and opened circles; the second stage was association of the protofilaments into straight protofilament bundles and toroids. In addition to these assemblies in GTP, highly curved oligomers and minirings could be observed after GTP hydrolysis or in the presence of GDP. Those three types of protofilaments of SyFtsZ provide support for the hypothesis for a constriction force based on curved protofilaments.

microbiology↗

bioRxiv2019

Highly Genotype- and Tissue-specific Single-Parent Expression Drives Dynamic Gene Expression Complementation in Maize Hybrids

Maize exhibits tremendous gene expression variation between different lines. Complementation of diverse gene expression patterns in hybrids could play an important role in the manifestation of heterosis. In this study, we used transcriptome data of five different tissues from 33 maize inbreds and 89 hybrids (430 samples in total) to survey the global gene expression landscape of F1-hybrids relative to their inbred parents. Analysis of this data set revealed that single parent expression (SPE), which is defined as gene expression in only one of the two parents, while commonly observed, is highly genotype- and tissue-specific. Genes that have SPE in at least one pair of inbreds also tend to be tissue-specific. Genes with SPE caused by genomic presence/absence variation (PAV SPE) are much more frequently expressed in hybrids than genes that are present in the genome of both inbreds, but expressed in only a single-parent (non-PAV SPE) (74.7% vs. 59.7%). For non-PAV SPE genes, allele specific expression was used to investigate whether parental alleles not expressed in the inbred line (\"silent allele\") can be actively transcribed in the hybrid. We found that expression of the silent allele in the hybrid is relatively rare ([~]6.3% of non-PAV SPE genes), but is observed in almost all hybrids and tissues. Non-PAV SPE genes with expression of the silent allele in the hybrid are more likely to exhibit above high-parent expression level in the hybrid than those that do not express the silent allele. Finally, both PAV SPE and non-PAV SPE genes are highly enriched for being classified as non-syntenic, but depleted for curated genes with experimentally determined functions. This study provides a more comprehensive understanding of the potential role of non-PAV SPE and PAV SPE genes in heterosis.

genomics↗

bioRxiv2019

Specialized NADPH diaphorase membrane-related localizations in the brainstem of the pigeons (Columba livia)

NADPH diaphorase (N-d) is used to a histochemical identification of subgroup of neuronal cells. Beside regular intracellular N-d positivity, membrane-related positivity revealed as a specialized staining pattern in the pigeon brain stem. In the investigation of the nervous system of homing pigeons (Columba livia) with N-d staining, we found a specialized structure, which temporally was termed as N-d tubular glomerular body/structure or as T-J body related to the last name of authors. This N-d positive specialization constituted by tubular components bilaterally located in the medial to the lemniscus spinalis in the medulla oblongata. The tubular components were moderate staining. T-J body was a longitudinal oriented structure of 2400 m with N-d staining. N-d positive tubular components were twisted and intermingled together. Beside the young adult pigeons, T-J body s were also consistently detected in the aged pigeons. Membrane-related staining were also detected in the other rostral nuclei in the brain stem. With discussion and review of related scientific literatures, T-J body was considered as a new anatomical structure or a new feature of the existent nucleus. In summary, beside N-d intracellular distribution, there were other three N-d membrane-related localizations: mini-aggregation, patch-aggregation, and arrangement along tubular unit.

neuroscience↗

bioRxiv2019

A novel role for Myosin-Va in mitochondrial fission

In cancer cells metabolic changes and mitochondrial morphology are coupled. It is known that the cytoskeleton and molecular motors are directly involved in regulating mitochondrial morphology. Here we show that myosin-Va, an actin-based molecular motor, is required for the malignant properties of melanoma cells and localizes to mitochondria in these cells. Knockdown of myosin-Va increases cellular respiration rates and ROS production and decreases glucose uptake and lactate secretion. In addition, knockdown of myosin-Va results in reduced mitochondrial fission and correspondingly elongated mitochondria. We show that myosin-Va interacts with the mitochondrial outer membrane protein Spire1C, an actin-regulatory protein implicated in mitochondrial fission, and that Spire1C recruits myosin-Va to mitochondria. Finally, we show that during mitochondrial fission myosin-Va localization to mitochondria increases, and that myosin-Va localizes to mitochondrial fission sites immediately adjacent to Drp1 punctae. We conclude that myosin-Va facilitates mitochondrial fission. These data implicate myosin-Va as a target for the Warburg effect in melanoma cells.\n\nO_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=81 SRC=\"FIGDIR/small/655803v1_ufig1.gif\" ALT=\"Figure 1\">\nView larger version (35K):\norg.highwire.dtl.DTLVardef@1130e72org.highwire.dtl.DTLVardef@196619org.highwire.dtl.DTLVardef@17e09edorg.highwire.dtl.DTLVardef@1bdc311_HPS_FORMAT_FIGEXP M_FIG C_FIG

cell biology↗

bioRxiv2019

A comparative assessment of aging-related NADPH diaphorase positivity in the spinal cord and medullary oblongata between pigeon and murine

NADPH diaphorase (N-d) positive neurons has been examined in many animals. N-d neurodegenerative neurites were detected in some animal models. However, detailed information of N-d positivity and aging related changes was still lack in the spinal cord and medulla oblongata of pigeons. In this study, we evaluated the N-d positivity and aging alterations in the spinal cord and medullary oblongata of the pigeon compared with rat and mouse. In pigeons, N-d neurons were more numerous in the dorsal horn, around the central canal and in the column of Terni in the thoracic and lumbar segments and scattered neurons occurred in the ventral horn of spinal segments. N-d neurons also occurred in the white matter of spinal cord. Morphometrical analysis demonstrated in the lumbosacral, cervical and thoracic regions. Compared with young pigeons, the size of N-d soma was significantly altered in aged pigeons. Meanwhile, the dramatic morphological changes occurred in the lumbar to sacral segments. The most important findings of this study were aging-related N-d positive bodies (ANB) in aged pigeons, mainly in the nucleus cuneatus externus (CuE), occasionally in the nuclei gracilis et cuneatus. ANBs were identified in the gracile nuclei in spinal cord in the aged rats and mice. ANBs were also detected in the CuE spinal nucleus in the aged rats. Immunohistochemistry also showed that the aging changes occurred in the cell types and neuropeptides in aged animals. The results suggested the weak inflammation and neuronal dysfunction in the spinal cord in aged pigeons. Our results suggested that the ANB could be considered as aging marker in the central nervous system.

neuroscience↗