scholarly journals Converging preganglionic axons refine without synaptic transmission when targets downstream of sympathetic nerves are active

2020 ◽  
Author(s):  
Yumaine Chong ◽  
Ellis Cooper
Keyword(s):  
Synaptic Transmission ◽  
Single Cell ◽  
Sympathetic Neurons ◽  
Sympathetic Nerves ◽  
Sympathetic Ganglia ◽  
Synaptic Activity ◽  
Postsynaptic Activity ◽  
Single Cell Rna Sequencing ◽  
The Impact ◽  
Target Activity

AbstractIt is well accepted that refinement of converging presynaptic inputs depends on postsynaptic activity; however, it remains unclear how this developmental event is initiated. To address this, we developed a mosaic model where synaptically-active and synaptically-inactive sympathetic neurons develop side-by-side in the same ganglion. Surprisingly, we show that converging presynaptic inputs refine on neurons even without synaptic transmission as long as the synaptically-silent neurons share targets with synaptically-active neurons. In addition, our single-cell RNA sequencing experiments show that sympathetic ganglia contain at least 7 neuronal subtypes that decode the impact of synaptic activity differently, including their ability to maintain an adrenergic phenotype. Our results provide a new view on the roles that synaptic transmission and retrograde target activity have on developing circuits.

scholarly journals Quality assessment of single-cell RNA sequencing data by coverage skewness analysis

2019 ◽  
Author(s):  
Imad Abugessaisa ◽  
Shuhei Noguchi ◽  
Melissa Cardon ◽  
Akira Hasegawa ◽  
Kazuhide Watanabe ◽  
...  
Keyword(s):  
Quality Assessment ◽  
Single Cell ◽  
Rna Sequencing ◽  
Single Cells ◽  
Assessment Method ◽  
Poor Quality ◽  
Sequencing Data ◽  
Single Cell Rna Sequencing ◽  
Gene Coverage ◽  
The Impact

AbstractAnalysis and interpretation of single-cell RNA-sequencing (scRNA-seq) experiments are compromised by the presence of poor quality cells. For meaningful analyses, such poor quality cells should be excluded to avoid biases and large variation. However, no clear guidelines exist. We introduce SkewC, a novel quality-assessment method to identify poor quality single-cells in scRNA-seq experiments. The method is based on the assessment of gene coverage for each single cell and its skewness as a quality measure. To validate the method, we investigated the impact of poor quality cells on downstream analyses and compared biological differences between typical and poor quality cells. Moreover, we measured the ratio of intergenic expression, suggesting genomic contamination, and foreign organism contamination of single-cell samples. SkewC is tested in 37,993 single-cells generated by 15 scRNA-seq protocols. We envision SkewC as an indispensable QC method to be incorporated into scRNA-seq experiment to preclude the possibility of scRNA-seq data misinterpretation.

scholarly journals Excitatory Muscarinic Modulation Strengthens Virtual Nicotinic Synapses on Sympathetic Neurons and Thereby Enhances Synaptic Gain

2006 ◽  
Vol 96 (6) ◽  
pp. 3104-3113 ◽  
Author(s):  
Paul H. M. Kullmann ◽  
John P. Horn
Keyword(s):  
Sympathetic Neurons ◽  
Sympathetic Ganglia ◽  
Dynamic Clamp ◽  
Neuronal Types ◽  
Synaptic Gain ◽  
Nicotinic Synapses ◽  
M1 Muscarinic ◽  
The Impact ◽  
Muscarinic Modulation ◽  
M1 Muscarinic Receptors

Acetylcholine excites many neuronal types by binding to postsynaptic m1-muscarinic receptors that signal to ion channels through the Gq/11 protein. To investigate the functional significance of this metabotropic pathway in sympathetic ganglia, we studied how muscarinic excitation modulated the integration of virtual nicotinic excitatory postsynaptic potentials (EPSPs) created in dissociated bullfrog B-type sympathetic neurons with the dynamic-clamp technique. Muscarine (1 μM) strengthened the impact of virtual synapses by reducing the artificial nicotinic conductance required to reach the postsynaptic firing threshold from 20.9 ± 5.4 to 13.1 ± 3.1 nS. Consequently, postganglionic action potential output increased by 4–215% when driven by different patterns of virtual presynaptic activity that were chosen to reflect the range of physiological firing rates and convergence levels seen in amphibian and mammalian sympathetic ganglia. In addition to inhibiting the M-type K+ conductance, muscarine activated a leak conductance in three of 37 cells. When this leak conductance was reproduced with the dynamic clamp, it also acted to strengthen virtual nicotinic synapses and enhance postganglionic spike output. Combining pharmacological M-conductance suppression with virtual leak activation, at resting potentials between −50 and −55 mV, produced synergistic strengthening of nicotinic synapses and an increase in the integrated postganglionic spike output. Together, these results reveal how muscarinic activation of a branched metabotropic pathway can enhance integration of fast EPSPs by modulating their effective strength. The results also support the hypothesis that muscarinic synapses permit faster and more accurate feedback control of autonomic behaviors by generating gain through synaptic amplification in sympathetic ganglia.

Abstract A10: Using single-cell RNA sequencing to assess the impact of pancreatic oncogenic Kras on macrophage gene expression in vitro

2019 ◽  
Author(s):  
Katelyn Donahue ◽  
Yaqing Zhang ◽  
Veerin Sirihorachai ◽  
Stephanie The ◽  
Arvind Rao ◽  
...  
Keyword(s):  
Gene Expression ◽  
Single Cell ◽  
Rna Sequencing ◽  
Single Cell Rna Sequencing ◽  
The Impact

scholarly journals Novel target identification using single cell sequencing and electrophysiology of cardiac sympathetic neurons in disease

2019 ◽  
Author(s):  
Harvey Davis ◽  
Neil Herring ◽  
David J Paterson
Keyword(s):  
Single Cell ◽  
Target Identification ◽  
Sodium Current ◽  
Sympathetic Neurons ◽  
Sympathetic Nerves ◽  
Underlying Mechanism ◽  
Neuronal Firing ◽  
Surgical Removal ◽  
Spontaneously Hypertensive ◽  
Stellate Ganglia

AbstractThe activity of cardiac sympathetic nerves from the stellate ganglia is increased in many cardiovascular diseases contributing to the pathophysiology, however the mechanisms underlying this are unknown. Moreover, clinical studies show their surgical removal is an effective treatment, despite the biophysical properties of these neurons being largely unstudied. Here we demonstrate that stellate ganglia neurons from prehypertensive spontaneously hypertensive rats are hyperactive and describe in detail their electrophysiological phenotype guided by single cell RNA-sequencing, molecular biology and perforated patch-clamp to uncover the underlying mechanism. The expression of key transcripts was confirmed in human stellate ganglia. We further demonstrate the contribution of a plethora of ion channels to stellate ganglia neuronal firing, and show that hyperexcitability was curbed by M-current activators, non-selective sodium current blockers or inhibition of Nav1.1-1.3, Nav1.6 or INaP. These findings have implications for target discovery to reduce cardiac sympathetic activity without resorting to surgery.

scholarly journals Single-cell RNA sequencing of a European and an African lymphoblastoid cell line

2019 ◽  
Author(s):  
Daniel Osorio ◽  
Xue Yu ◽  
Peng Yu ◽  
Erchin Serpedin ◽  
James J. Cai
Keyword(s):  
Gene Expression ◽  
Single Cell ◽  
Rna Sequencing ◽  
African Ancestry ◽  
Peripheral Blood Lymphocytes ◽  
Barr Virus ◽  
Single Cell Rna Sequencing ◽  
Suitable Reference ◽  
The Impact

AbstractIn biomedical research, lymphoblastoid cell lines (LCLs), often established byin vitroinfection of resting B cells with Epstein Barr Virus, are commonly used as surrogates for peripheral blood lymphocytes. Genomic and transcriptomic information on LCLs has been used to study the impact of genetic variation on gene expression in humans. Here we present single-cell RNA sequencing (scRNA-seq) data on GM12878 and GM18502—two LCLs derived from the blood of female donors of European and African ancestry, respectively. Cells from three samples (the two LCLs and a 1:1 mixture of the two) were prepared separately using a 10X Genomics Chromium Controller and deeply sequenced. The final dataset contained 7,045 cells from GM12878, 5,189 from GM18502, and 5,820 from the mixture, offering valuable information on single-cell gene expression in highly homogenous cell populations. This dataset is a suitable reference of population differentiation in gene expression at the single-cell level. Data from the mixture provides additional valuable information facilitating the development of statistical methods for data normalization and batch effect correction.

scholarly journals Chronic opioid treatment arrests neurodevelopment and alters synaptic activity in human midbrain organoids

2021 ◽  
Author(s):  
Hye Sung Kim ◽  
Yang Xiao ◽  
Xuejing Chen ◽  
Siyu He ◽  
Jongwon Im ◽  
...  
Keyword(s):  
Single Cell ◽  
Single Cells ◽  
Cell Lineage ◽  
Induced Pluripotent Stem Cell ◽  
Synaptic Activity ◽  
Gene Expressions ◽  
Opioid Treatment ◽  
Cell Type Specific ◽  
Induced Pluripotent ◽  
The Impact

SummaryThe impact of long-term opioid exposure on the embryonic brain is crucial to healthcare due to the surging number of pregnant mothers with an opioid dependency. Current studies on the neuronal effects are limited due to human brain inaccessibility and cross-species differences among animal models. Here, we report a model to assess cell-type specific responses to acute and chronic fentanyl treatment, as well as fentanyl withdrawal, using human induced pluripotent stem cell (hiPSC)-derived midbrain organoids. Single cell mRNA sequencing (25,510 single cells in total) results suggest that chronic fentanyl treatment arrests neuronal subtype specification during early midbrain development and alters the pathways associated with synaptic activities and neuron projection. Acute fentanyl treatment, however, increases dopamine release but does not induce significant changes in gene expressions of cell lineage development. To date, our study is the first unbiased examination of midbrain transcriptomics with synthetic opioid treatment at the single cell level.

Single-cell RNA-sequencing reveals profound changes in circulating immune cells in patients with heart failure

2020 ◽  
Author(s):  
Wesley T Abplanalp ◽  
David John ◽  
Sebastian Cremer ◽  
Birgit Assmus ◽  
Lena Dorsheimer ◽  
...  
Keyword(s):  
Heart Failure ◽  
Flow Cytometry ◽  
Single Cell ◽  
Rna Sequencing ◽  
Immune Cells ◽  
Healthy Subjects ◽  
Patients With Heart Failure ◽  
Single Cell Rna Sequencing ◽  
The Impact ◽  
Classical Monocytes

Abstract Aims Identification of signatures of immune cells at single-cell level may provide novel insights into changes of immune-related disorders. Therefore, we used single-cell RNA-sequencing to determine the impact of heart failure on circulating immune cells. Methods and results We demonstrate a significant change in monocyte to T-cell ratio in patients with heart failure, compared to healthy subjects, which were validated by flow cytometry analysis. Subclustering of monocytes and stratification of the clusters according to relative CD14 and FCGR3A (CD16) expression allowed annotation of classical, intermediate, and non-classical monocytes. Heart failure had a specific impact on the gene expression patterns in these subpopulations. Metabolically active genes such as FABP5 were highly enriched in classical monocytes of heart failure patients, whereas β-catenin expression was significantly higher in intermediate monocytes. The selective regulation of signatures in the monocyte subpopulations was validated by classical and multifactor dimensionality reduction flow cytometry analyses. Conclusion Together this study shows that circulating cells derived from patients with heart failure have altered phenotypes. These data provide a rich source for identification of signatures of immune cells in heart failure compared to healthy subjects. The observed increase in FABP5 and signatures of Wnt signalling may contribute to enhanced monocyte activation.

scholarly journals Neuroligin3 splice isoforms shape inhibitory synaptic function in the mouse hippocampus

2020 ◽  
Vol 295 (25) ◽  
pp. 8589-8595 ◽  
Author(s):  
Motokazu Uchigashima ◽  
Ming Leung ◽  
Takuya Watanabe ◽  
Amy Cheung ◽  
Timmy Le ◽  
...  
Keyword(s):  
Synaptic Transmission ◽  
Single Cell ◽  
Pyramidal Neurons ◽  
Autism Spectrum ◽  
Synaptic Function ◽  
Synaptic Activity ◽  
Dependent Manner ◽  
Splice Isoforms ◽  
Inhibitory Synaptic Transmission ◽  
Ca1 Pyramidal Neurons

Synapse formation is a dynamic process essential for the development and maturation of the neuronal circuitry in the brain. At the synaptic cleft, trans-synaptic protein–protein interactions are major biological determinants of proper synapse efficacy. The balance of excitatory and inhibitory synaptic transmission (E-I balance) stabilizes synaptic activity, and dysregulation of the E-I balance has been implicated in neurodevelopmental disorders, including autism spectrum disorders. However, the molecular mechanisms underlying the E-I balance remain to be elucidated. Here, using single-cell transcriptomics, immunohistochemistry, and electrophysiology approaches to murine CA1 pyramidal neurons obtained from organotypic hippocampal slice cultures, we investigate neuroligin (Nlgn) genes that encode a family of postsynaptic adhesion molecules known to shape excitatory and inhibitory synaptic function. We demonstrate that the NLGN3 protein differentially regulates inhibitory synaptic transmission in a splice isoform–dependent manner at hippocampal CA1 synapses. We also found that distinct subcellular localizations of the NLGN3 isoforms contribute to the functional differences observed among these isoforms. Finally, results from single-cell RNA-Seq analyses revealed that Nlgn1 and Nlgn3 are the major murine Nlgn genes and that the expression levels of the Nlgn splice isoforms are highly diverse in CA1 pyramidal neurons. Our results delineate isoform-specific effects of Nlgn genes on the E-I balance in the murine hippocampus.

scholarly journals Single‐cell RNA Sequencing reveals molecular heterogeneity of glia within mouse sympathetic ganglia

2020 ◽  
Vol 34 (S1) ◽  
pp. 1-1
Author(s):  
Valerie Yeh-Shing Hsieh van Weperen ◽  
Jaime Contreras ◽  
Russell Littman ◽  
Olujimi A. Ajijola
Keyword(s):  
Single Cell ◽  
Rna Sequencing ◽  
Sympathetic Ganglia ◽  
Molecular Heterogeneity ◽  
Single Cell Rna Sequencing

scholarly journals Single-Cell RNA Sequencing and Assay for Transposase-Accessible Chromatin Using Sequencing Reveals Cellular and Molecular Dynamics of Aortic Aging in Mice

2021 ◽  
Author(s):  
Wenhui Xie ◽  
Yilang Ke ◽  
Qinyi You ◽  
Jing Li ◽  
Lu Chen ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Single Cell ◽  
Rna Sequencing ◽  
Chromatin Accessibility ◽  
Open Chromatin ◽  
Vascular Aging ◽  
Chromatin States ◽  
Single Cell Rna Sequencing ◽  
The Impact ◽  
Accessible Chromatin

Objective: The impact of vascular aging on cardiovascular diseases has been extensively studied; however, little is known regarding the cellular and molecular mechanisms underlying age-related vascular aging in aortic cellular subpopulations. Approach and Results: Transcriptomes and transposase-accessible chromatin profiles from the aortas of 4-, 26-, and 86-week-old C57/BL6J mice were analyzed using single-cell RNA sequencing and assay for transposase-accessible chromatin sequencing. By integrating the heterogeneous transcriptome and chromatin accessibility data, we identified cell-specific TF (transcription factor) regulatory networks and open chromatin states. We also determined that aortic aging affects cell interactions, inflammation, cell type composition, dysregulation of transcriptional control, and chromatin accessibility. Endothelial cells 1 have higher gene set activity related to cellular senescence and aging than do endothelial cells 2. Moreover, construction of senescence trajectories shows that endothelial cell 1 and fibroblast senescence is associated with distinct TF open chromatin states and an mRNA expression model. Conclusions: Our data provide a system-wide model for transcriptional and epigenetic regulation during aortic aging at single-cell resolution.

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