scholarly journals COUNTEN – an AI-driven tool for rapid, and objective structural analyses of the Enteric Nervous System

2020 ◽  
Author(s):  
Yuta Kobayashi ◽  
Alicia Bukowski ◽  
Subhamoy Das ◽  
Cedric Espenel ◽  
Julieta Gomez-Frittelli ◽  
...  
Keyword(s):  
Nervous System ◽  
Enteric Nervous System ◽  
Normal Structure ◽  
Enteric Neurons ◽  
Comprehensive Understanding ◽  
Large Area ◽  
Myenteric Neurons ◽  
Tissue Region ◽  
Subjective Bias ◽  
Myenteric Ganglia

AbstractHealthy gastrointestinal functions require a healthy Enteric Nervous System (ENS). ENS health is often defined by the presence of normal ENS structure. However, we currently lack a comprehensive understanding of normal ENS structure as current methodologies of manual enumeration of neurons within tissue and ganglia can only parse limited tissue regions; and are prone to error, subjective bias, and peer-to-peer discordance. Thus, there is a need to craft objective methods and robust tools to capture and quantify enteric neurons over a large area of tissue and within multiple ganglia. Here, we report on the development of an AI-driven tool COUNTEN which parses HuC/D-immunolabeled adult murine myenteric ileal plexus tissues to enumerate and classify enteric neurons into ganglia in a rapid, robust, and objective manner. COUNTEN matches trained humans in identifying, enumerating and clustering myenteric neurons into ganglia but takes a fraction of the time, thus allowing for accurate and rapid analyses of a large tissue region. Using COUNTEN, we parsed thousands of myenteric neurons and clustered them in hundreds of myenteric ganglia to compute metrics that help define the normal structure of the adult murine ileal myenteric plexus. We have made COUNTEN freely and openly available to all researchers, to facilitate reproducible, robust, and objective measures of ENS structure across mouse models, experiments, and institutions.

scholarly journals Adult enteric nervous system in health is maintained by a dynamic balance between neuronal apoptosis and neurogenesis

2017 ◽  
Vol 114 (18) ◽  
pp. E3709-E3718 ◽  
Author(s):  
Subhash Kulkarni ◽  
Maria-Adelaide Micci ◽  
Jenna Leser ◽  
Changsik Shin ◽  
Shiue-Cheng Tang ◽  
...  
Keyword(s):  
Nervous System ◽  
Enteric Nervous System ◽  
Dynamic Balance ◽  
Neuronal Cell ◽  
Cell Loss ◽  
Enteric Neurons ◽  
Phosphatase And Tensin Homolog ◽  
Tensin Homolog ◽  
Myenteric Ganglia

According to current dogma, there is little or no ongoing neurogenesis in the fully developed adult enteric nervous system. This lack of neurogenesis leaves unanswered the question of how enteric neuronal populations are maintained in adult guts, given previous reports of ongoing neuronal death. Here, we confirm that despite ongoing neuronal cell loss because of apoptosis in the myenteric ganglia of the adult small intestine, total myenteric neuronal numbers remain constant. This observed neuronal homeostasis is maintained by new neurons formed in vivo from dividing precursor cells that are located within myenteric ganglia and express both Nestin and p75NTR, but not the pan-glial marker Sox10. Mutation of the phosphatase and tensin homolog gene in this pool of adult precursors leads to an increase in enteric neuronal number, resulting in ganglioneuromatosis, modeling the corresponding disorder in humans. Taken together, our results show significant turnover and neurogenesis of adult enteric neurons and provide a paradigm for understanding the enteric nervous system in health and disease.

Positive allosteric modulation of endogenous delta opioid receptor signaling in the enteric nervous system is a potential treatment for gut motility disorders

2021 ◽  
Author(s):  
Jesse J DiCello ◽  
Simona Elisa Carbone ◽  
Ayame Saito ◽  
Vi Pham ◽  
Agata Szymaszkiewicz ◽  
...  
Keyword(s):  
Nervous System ◽  
Enteric Nervous System ◽  
Opioid Receptor ◽  
Allosteric Modulation ◽  
Enteric Neurons ◽  
Delta Opioid Receptor ◽  
Motility Disorders ◽  
Myenteric Neurons ◽  
Mouse Colon ◽  
Promising Therapeutic Approach

Background and Purpose: Allosteric modulators (AMs) are molecules that can fine-tune signaling by G protein-coupled receptors (GPCRs). Although they are a promising therapeutic approach for treating a range of disorders, allosteric modulation of GPCRs in the context of the enteric nervous system (ENS) and digestive dysfunction remains largely unexplored. This study examined allosteric modulation of the delta opioid receptor (DOR) in the ENS and assessed the suitability of DOR AMs for the treatment of irritable bowel syndrome (IBS) symptoms using mouse models. Experimental Approach: The effects of the positive allosteric modulator (PAM) of DOR, BMS-986187, on neurogenic contractions of the mouse colon and on DOR internalization in enteric neurons were quantified. The ability of BMS-986187 to influence colonic motility was assessed both in vitro and in vivo. Key Results: BMS-986187 displayed DOR selective PAM-agonist activity and orthosteric agonist probe-dependence in the mouse colon. BMS-986187 augmented the inhibitory effects of DOR agonists on neurogenic contractions and enhanced reflex-evoked DOR internalization in myenteric neurons. BMS-986187 significantly increased DOR endocytosis in myenteric neurons in response to the weakly internalizing agonist ARM390. BMS-986187 reduced the generation of complex motor patterns in the isolated intact colon. BMS-986187 reduced fecal output and diarrhea onset in the novel environment stress and castor oil models of IBS symptoms, respectively. Conclusion and Implications: DOR PAMs enhance DOR-mediated signaling in the ENS and have potential benefit for the treatment of dysmotility. This study provides proof of concept to support the use of GPCR AMs for treatment of gastrointestinal motility disorders.

scholarly journals Computational simulations and Ca2+ imaging reveal that slow synaptic depolarizations (slow EPSPs) inhibit fast EPSP evoked action potentials for most of their time course in enteric neurons

2021 ◽  
Author(s):  
Parvin Zarei Eskikand ◽  
Katerina Koussoulas ◽  
Rachel M. Gwynne ◽  
Joel C. Bornstein
Keyword(s):  
Nervous System ◽  
Ion Channels ◽  
Enteric Nervous System ◽  
Action Potentials ◽  
Enteric Neurons ◽  
Autonomous Nervous System ◽  
Myenteric Neurons ◽  
Synaptic Potentials ◽  
Mouse Colon ◽  
Time Courses

AbstractTransmission between neurons in the extensive enteric neural networks of the gut involves synaptic potentials with vastly different time courses and underlying conductances. Most enteric neurons exhibit fast excitatory post-synaptic potentials (EPSPs) lasting 20-50 ms, but many also exhibit slow EPSPs that last up to 100 s. When large enough, slow EPSPs excite action potentials at the start of the slow depolarization, but how they affect action potentials evoked by fast EPSPs is unknown. Furthermore, two other sources of synaptic depolarization probably occur in enteric circuits, activated via GABAA or GABAC receptors; how these interact with other synaptic depolarizations is also unclear. We built a compartmental model of enteric neurons incorporating realistic voltage-dependent ion channels, then simulated fast EPSPs, slow EPSPs and GABAA or GABAC ligand-gated Cl- channels to explore these interactions. Model predictions were tested by imaging Ca2+ transients in myenteric neurons ex vivo as an indicator of their activity during synaptic interactions. The model could mimic firing of myenteric neurons in mouse colon evoked by depolarizing current during intracellular recording and the fast and slow EPSPs in these neurons. Subthreshold fast EPSPs evoked spikes during the rising phase of a slow EPSP, but suprathreshold fast EPSPs could not evoke spikes later in a slow EPSP. This predicted inhibition was confirmed by Ca2+ imaging in which stimuli that evoke slow EPSPs suppressed activity evoked by fast EPSPs in many myenteric neurons. The model also predicted that synchronous activation of GABAA receptors and fast EPSPs potentiated firing evoked by the latter, while synchronous activation of GABAC receptors with fast EPSPs, potentiated firing and then suppressed it. The results reveal that so-called slow EPSPs have a biphasic effect being likely to suppress fast EPSP evoked firing over very long periods, perhaps accounting for prolonged quiescent periods seen in enteric motor patterns.Author SummaryThe gastrointestinal tract is the only organ with an extensive semi-autonomous nervous system that generates complex contraction patterns independently. Communication between neurons in this “enteric” nervous system is via depolarizing synaptic events with dramatically different time courses including fast synaptic potentials lasting around 20-50 ms and slow depolarizing synaptic potentials lasting for 10 – 120 s. Most neurons have both. We explored how slow synaptic depolarizations affect generation of action potentials by fast synaptic potentials using computational simulation of small networks of neurons implemented as compartmental models with realistic membrane ion channels. We found that slow synaptic depolarizations have biphasic effects; they initially make fast synaptic potentials more likely to trigger action potentials, but then actually prevent action potential generation by fast synaptic potentials with the inhibition lasting several 10s of seconds. We confirmed the inhibitory effects of the slow synaptic depolarizations using live Ca imaging of enteric neurons from mouse colon in isolated tissue. Our results identify a novel form of synaptic inhibition in the enteric nervous system of the gut, which may account for the vastly differing time courses between signalling in individual gut neurons and rhythmic contractile patterns that often repeat at more than 60 s intervals.

In ovo transplantation of enteric nervous system precursors from vagal to sacral neural crest results in extensive hindgut colonisation

Development ◽  
2002 ◽  
Vol 129 (12) ◽  
pp. 2785-2796 ◽  
Author(s):  
Alan J. Burns ◽  
Jean-Marie M. Delalande ◽  
Nicole M. Le Douarin
Keyword(s):  
Nervous System ◽  
Neural Crest ◽  
Enteric Nervous System ◽  
Enteric Neurons ◽  
In Ovo ◽  
Neuronal Marker ◽  
Sacral Region ◽  
Enteric Ganglia ◽  
Migration Front ◽  
Sacral Neural Crest

The enteric nervous system (ENS) is derived from vagal and sacral neural crest cells (NCC). Within the embryonic avian gut, vagal NCC migrate in a rostrocaudal direction to form the majority of neurons and glia along the entire length of the gastrointestinal tract, whereas sacral NCC migrate in an opposing caudorostral direction, initially forming the nerve of Remak, and contribute a smaller number of ENS cells primarily to the distal hindgut. In this study, we have investigated the ability of vagal NCC, transplanted to the sacral region of the neuraxis, to colonise the chick hindgut and form the ENS in an experimentally generated hypoganglionic hindgut in ovo model. Results showed that when the vagal NC was transplanted into the sacral region of the neuraxis, vagal-derived ENS precursors immediately migrated away from the neural tube along characteristic pathways, with numerous cells colonising the gut mesenchyme by embryonic day (E) 4. By E7, the colorectum was extensively colonised by transplanted vagal NCC and the migration front had advanced caudorostrally to the level of the umbilicus. By E10, the stage at which sacral NCC begin to colonise the hindgut in large numbers, myenteric and submucosal plexuses in the hindgut almost entirely composed of transplanted vagal NCC, while the migration front had progressed into the pre-umbilical intestine, midway between the stomach and umbilicus. Immunohistochemical staining with the pan-neuronal marker, ANNA-1, revealed that the transplanted vagal NCC differentiated into enteric neurons, and whole-mount staining with NADPH-diaphorase showed that myenteric and submucosal ganglia formed interconnecting plexuses, similar to control animals. Furthermore, using an anti-RET antibody, widespread immunostaining was observed throughout the ENS, within a subpopulation of sacral NC-derived ENS precursors, and in the majority of transplanted vagal-to-sacral NCC. Our results demonstrate that: (1) a cell autonomous difference exists between the migration/signalling mechanisms used by sacral and vagal NCC, as transplanted vagal cells migrated along pathways normally followed by sacral cells, but did so in much larger numbers, earlier in development; (2) vagal NCC transplanted into the sacral neuraxis extensively colonised the hindgut, migrated in a caudorostral direction, differentiated into neuronal phenotypes, and formed enteric plexuses; (3) RET immunostaining occurred in vagal crest-derived ENS cells, the nerve of Remak and a subpopulation of sacral NCC within hindgut enteric ganglia.

scholarly journals Bisphenol A (BPA) Affects the Enteric Nervous System in the Porcine Stomach

Animals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2445
Author(s):  
Krystyna Makowska ◽  
Sławomir Gonkowski
Keyword(s):  
Nervous System ◽  
Bisphenol A ◽  
Enteric Nervous System ◽  
Gastric Wall ◽  
Cholinergic Neurons ◽  
Double Immunofluorescence ◽  
Adaptive Processes ◽  
Living Organisms ◽  
The Impact ◽  
Myenteric Ganglia

Bisphenol A (BPA) is widely utilized in plastic production process all over the world. Previous studies have shown that BPA, with its similarity to estrogen, may negatively affect living organisms. It is acknowledged that BPA distorts the activity of multiple internal systems, including the nervous, reproductive, urinary, and endocrine systems. BPA also affects the gastrointestinal tract and enteric nervous system (ENS), which is placed throughout the wall from the esophagus to the rectum. Contrary to the intestine, the influence of BPA on the ENS in the stomach is still little known. This study, performed using the double immunofluorescence method, has revealed that BPA affects the number of nervous structures in the porcine gastric wall immunoreactive to vesicular acetylcholine transporter (VAChT, a marker of cholinergic neurons), substance P (SP), vasoactive intestinal polypeptide (VIP), galanin (GAL) and cocaine- and amphetamine-regulated transcript peptide (CART). The character and severity of noted alterations depended on the part of the ENS, the BPA dose, and the type of neuronal substance. Administration of BPA resulted in an increase in the number of nervous structures containing SP, GAL, and/or CART, and a decrease in the number of cholinergic neurons in all parts of the gastric wall. The number of VIP-positive nervous structures increased in the enteric myenteric ganglia, along with the muscular and mucosal layers, whilst it decreased in the submucous ganglia. The exact mechanism of noted changes was not absolutely obvious, but they were probably related to the neuroprotective and adaptive processes constituting the response to the impact of BPA.

scholarly journals Abnormalities of the intestinal pacemaker cells, enteric neurons, and smooth muscle in intestinal atresia

2019 ◽  
Vol 11 (03) ◽  
pp. 180-185 ◽  
Author(s):  
Radhika krishna OH ◽  
Mohammed Abdul Aleem ◽  
Geetha Kayla
Keyword(s):  
Nervous System ◽  
Small Bowel ◽  
Enteric Nervous System ◽  
Gastrointestinal Motility ◽  
Interstitial Cells Of Cajal ◽  
Interstitial Cells ◽  
Enteric Neurons ◽  
Small Bowel Atresia ◽  
Bowel Atresia ◽  
Cells Of Cajal

Abstract BACKGROUND: Small bowel atresia is a congenital disorder that carves a substantial morbidity. Numerous postoperative gastrointestinal motility problems occur. The underlying cause of this motility disorder is still unclear. Interstitial cells of Cajal (ICC) play a major role in gastrointestinal motility. AIMS AND OBJECTIVES: To investigate the morphological changes of enteric nervous system and ICC in small bowel atresia. MATERIAL AND METHODS: Resected small bowel specimen from affected patients (n=15) were divided into three parts (proximal, distal, atretic). Standard histology and immunohistochemistry with anti C-KIT receptor antibody (CD117), calretinin and α-SMA was carried out. The density of myenteric ICCs in the proximal, atretic and distal parts was demonstrated by CD 117 while Calretinin was used for ganglion cells and nerve bundles, α-SMA highlighted muscle hypertrophy. RESULT AND CONCLUSION: The proximal and distal bowel revealed clear changes in the morphology and density of enteric nervous system and interstitial cells of Cajal..

scholarly journals G protein-coupled receptor trafficking and signaling: new insights into the enteric nervous system

2019 ◽  
Vol 316 (4) ◽  
pp. G446-G452 ◽  
Author(s):  
Simona E. Carbone ◽  
Nicholas A. Veldhuis ◽  
Arisbel B. Gondin ◽  
Daniel P. Poole
Keyword(s):  
Nervous System ◽  
Enteric Nervous System ◽  
G Protein ◽  
Molecular Mechanisms ◽  
Intestinal Inflammation ◽  
Receptor Expression ◽  
Enteric Neurons ◽  
Future Research ◽  
Detailed Knowledge ◽  
G Protein Coupled

G protein-coupled receptors (GPCRs) are essential for the neurogenic control of gastrointestinal (GI) function and are important and emerging therapeutic targets in the gut. Detailed knowledge of both the distribution and functional expression of GPCRs in the enteric nervous system (ENS) is critical toward advancing our understanding of how these receptors contribute to GI function during physiological and pathophysiological states. Equally important, but less well defined, is the complex relationship between receptor expression, ligand binding, signaling, and trafficking within enteric neurons. Neuronal GPCRs are internalized following exposure to agonists and under pathological conditions, such as intestinal inflammation. However, the relationship between the intracellular distribution of GPCRs and their signaling outputs in this setting remains a “black box”. This review will briefly summarize current knowledge of agonist-evoked GPCR trafficking and location-specific signaling in the ENS and identifies key areas where future research could be focused. Greater understanding of the cellular and molecular mechanisms involved in regulating GPCR signaling in the ENS will provide new insights into GI function and may open novel avenues for therapeutic targeting of GPCRs for the treatment of digestive disorders.

scholarly journals Emerging neuropeptide targets in inflammation: NPY and VIP

2013 ◽  
Vol 304 (11) ◽  
pp. G949-G957 ◽  
Author(s):  
Bindu Chandrasekharan ◽  
Behtash Ghazi Nezami ◽  
Shanthi Srinivasan
Keyword(s):  
Nervous System ◽  
Immune System ◽  
Enteric Nervous System ◽  
Intracellular Signaling ◽  
Enteric Neurons ◽  
Vast Number ◽  
Paracrine Effects ◽  
Intracellular Signaling Pathways ◽  
Inflammatory Processes ◽  
Epithelial Secretion

The enteric nervous system (ENS), referred to as the “second brain,” comprises a vast number of neurons that form an elegant network throughout the gastrointestinal tract. Neuropeptides produced by the ENS play a crucial role in the regulation of inflammatory processes via cross talk with the enteric immune system. In addition, neuropeptides have paracrine effects on epithelial secretion, thus regulating epithelial barrier functions and thereby susceptibility to inflammation. Ultimately the inflammatory response damages the enteric neurons themselves, resulting in deregulations in circuitry and gut motility. In this review, we have emphasized the concept of neurogenic inflammation and the interaction between the enteric immune system and enteric nervous system, focusing on neuropeptide Y (NPY) and vasoactive intestinal peptide (VIP). The alterations in the expression of NPY and VIP in inflammation and their significant roles in immunomodulation are discussed. We highlight the mechanism of action of these neuropeptides on immune cells, focusing on the key receptors as well as the intracellular signaling pathways that are activated to regulate the release of cytokines. In addition, we also examine the direct and indirect mechanisms of neuropeptide regulation of epithelial tight junctions and permeability, which are a crucial determinant of susceptibility to inflammation. Finally, we also discuss the potential of emerging neuropeptide-based therapies that utilize peptide agonists, antagonists, siRNA, oligonucleotides, and lentiviral vectors.

scholarly journals Targeting the Enteric Nervous System to Treat Metabolic Disorders? “Enterosynes” as Therapeutic Gut Factors

2019 ◽  
Vol 110 (1-2) ◽  
pp. 139-146 ◽  
Author(s):  
Claude Knauf ◽  
Anne Abot ◽  
Eve Wemelle ◽  
Patrice D. Cani
Keyword(s):  
Insulin Resistance ◽  
Nervous System ◽  
Enteric Nervous System ◽  
Proximal Part ◽  
Enteric Neurons ◽  
Diabetic Patients ◽  
Innovative Strategy ◽  
Treatment Of Diabetes

The gut-brain axis is of crucial importance for controlling glucose homeostasis. Alteration of this axis promotes the type 2 diabetes (T2D) phenotype (hyperglycaemia, insulin resistance). Recently, a new concept has emerged to demonstrate the crucial role of the enteric nervous system in the control of glycaemia via the hypothalamus. In diabetic patients and mice, modification of enteric neurons activity in the proximal part of the intestine generates a duodenal hyper-contractility that generates an aberrant message from the gut to the brain. In turn, the hypothalamus sends an aberrant efferent message that provokes a state of insulin resistance, which is characteristic of a T2D state. Targeting the enteric nervous system of the duodenum is now recognized as an innovative strategy for treatment of diabetes. By acting in the intestine, bioactive gut molecules that we called “enterosynes” can modulate the function of a specific type of neurons of the enteric nervous system to decrease the contraction of intestinal smooth muscle cells. Here, we focus on the origins of enterosynes (hormones, neurotransmitters, nutrients, microbiota, and immune factors), which could be considered therapeutic factors, and we describe their modes of action on enteric neurons. This unsuspected action of enterosynes is proposed for the treatment of T2D, but it could be applied for other therapeutic solutions that implicate communication between the gut and brain.

scholarly journals  Expression of corticotropin releasing factor (CRF) in the enteric nervous system of the jejunum of sheep

2011 ◽  
Vol 56 (No. 11) ◽  
pp. 551-560 ◽  
Author(s):  
A. Czujkowska ◽  
MB Arciszewski
Keyword(s):  
Nervous System ◽  
Smooth Muscle ◽  
Muscle Layer ◽  
Corticotropin Releasing Factor ◽  
Enteric Neurons ◽  
Nerve Fibres ◽  
Myenteric Neurons ◽  
Smooth Muscle Layer ◽  
Circular Smooth Muscle ◽  
A Minor

 Corticotropin releasing factor (CRF), a 41-amino acid neuropeptide widely distributed in the mammalian central nervous system, has been shown to influence several gastrointestinal functions. Recent studies show that CRF released locally from enteric nerves may also underlie alterations in gut function. In this study, immunohistochemisty was applied to demonstrate the presence of CRF in the jejunum of sheep. Using double immunohistochemical staining the co-localization of CRF with vasoactive intestinal peptide (VIP), galanin, tyrosine hydroxylase (TH), neuropeptide Y (NPY) and substance P (SP) was evaluated. The presence of CRF was detected in myenteric neurons (3.6 ± 0.9%) as well as in submucous neurons (10.5 ± 1.2%). In the ovine jejunum different numbers of CRF-expressing nerve fibres were detected in myenteric ganglia, submucous ganglia, circular smooth muscle layer, lamina muscularis mucosae and between mucosal glands. None of the CRF-positive enteric neurons and CRF-positive nerve fibres exhibited the presence of TH. CRF-immunoreactive (IR) myenteric neurons widely co-expressed VIP and/or NPY. A minor population of CRF-IR myenteric neurons additionally co-stored SP. Galanin was not present in CRF-IR myenteric neurons. The presence of VIP was observed in the vast majority of CRF-positive submucous neurons. Moderate numbers of CRF-IR sumbucous neurons co-expressing galanin or NPY were also found. The presence of SP in CRF-positive submucous neurons was noted only incidentally. In the circular smooth muscle layer CRF-IR/VIP-IR, CRF-IR/NPY-IR as well as CRF-IR/SP-IR nerve fibres were present. In the mucosal layer of the ovine jejunum CRF-IR nerve fibres co-stored additionally VIP, galanin, NPY or SP. This present study provides for the first time evidence that CRF present in different subclasses of enteric neurons may influence certain activities of the ovine jejunum. Co-localization studies indicate that VIP, galanin, SP and NPY functionally co-operate with CRF in the jejunum of the sheep.  

Sign in / Sign up

Export Citation Format

Share Document