Project description:The vagus nerve is a key component of the parasympathetic nervous system, innervating multiple abdominal organs to monitor and regulate their function. It forms the main neural pathway between the gastrointestinal tract and the brain, playing a major role in the regulation of energy homeostasis. The cell bodies for vagal sensory neurons reside in the nodose ganglia, with the left and right ganglia reported to have distinct roles in food intake and reward. Here, we have integrated our own single nucleus RNA sequencing data with multiple publicly available datasets to create a database of 108,482 nuclei and cells, and combined this with spatial transcriptomics to present a spatio-cellular transcriptional map of the mouse nodose ganglia, the ‘NodoMap’. Nodose ganglia neuronal cells clustered into twenty-two different subtypes, all found in both left and right nodose ganglia, but with significant differences in gene expression between left and right ganglia across multiple neuronal subtypes. Overnight fasting modulated gene expression across specific neuronal subtypes, including nutrient responsive pathways. Spatial transcriptomics showed that while vagal neuronal types were highly interspersed, patterns of organisation into cellular ‘neighbourhoods’ could be observed, with neighbourhoods identified of predominantly non-neuronal cells and of different neuronal populations accompanied by glial-like cells. Thus, NodoMap provides a detailed atlas of the mouse nodose ganglia in a spatial context, providing a platform for vagovagal neurocircuit analysis, and serving as an important resource to identify targets for pharmacotherapies for metabolic disease.
Project description:Vagal afferent neurons are thought to convey primarily physiological information, whereas spinal afferents transmit noxious signals from the viscera to the central nervous system. In order to elucidate molecular identities for these different properties, we compared gene expression profiles of neurons located in nodose ganglia (NG) and dorsal root ganglia (DRG) in mice. Intraperitoneal administration of Alexa Fluor-488 conjugated Cholera toxin B allowed identification of neurons projecting to the viscera. Fluorescent neurons in DRG (from T10 to T13) and NG were isolated using laser capture microdissection. Gene expression profiles of visceral afferent neurons, obtained by microarray hybridization, were analysed using multivariate spectral map analysis, SAM algorithm (Significance Analysis of Microarray data) and fold-difference filtering. A total of 1996 genes were found to be differentially expressed in DRG versus NG, including 41 G-protein coupled receptors and 60 ion channels. Expression profiles obtained on laser-captured neurons were contrasted to those obtained on whole ganglia demonstrating striking differences and the need for microdissection when studying visceral sensory neurons because of dilution of the signal by somatic sensory neurons. Furthermore, a detailed catalogue of all adrenergic and cholinergic, GABA, glutamate, serotonin and dopamine receptors, voltage-gated potassium, sodium and calcium channels and transient receptor potential cation channels present in visceral afferents is provided. Our genome-wide expression profiling data provide novel insight into molecular signatures that underlie both functional differences and similarities between NG and DRG visceral sensory neurons. Moreover, these findings will offer novel insight into mode of action of pharmacologic agents modulating visceral sensation. Experiment Overall Design: Three separate experiments were performed. First, 5 whole dorsal root ganglia were compared to 7 whole nodose ganglia. Second, Laser captured visceral neurons derived from 5 dorsal root ganglia and 5 nodose ganglia were compared on MG-U74Av2. Third, Laser captured visceral neurons derived from 9 dorsal root ganglia and 11 nodose ganglia were compared on Mouse430_2.
Project description:The nodose ganglia contain sensory neurons that play key roles in homeostatic behaviors and are supported by nodose glial cells. We used single cell RNA sequencing (scRNA-seq) to interrogate the molecular diversity of nodose glial cells shortly after birth.
Project description:Guided by gut sensory cues, humans and animals prefer nutritive sugars over non-caloric sweeteners. But how the gut differentiates such stimuli to rapidly guide preferences remains unknown. In the intestine, innervated enteroendocrine cells synapse with the vagus nerve to convey luminal sugar stimuli to the brain within seconds. Here, we sequenced individual vagal nodose neuron cells from the left and right nodose to assess their relative contribution to sugar signaling from the gut. The neurons lack expression of sugar receptors and transporters, but do express receptors for neurotransmitters and neuropeptides secreted by intestinal sensory epithelial cells.
Project description:Capsaicin-sensitive (Trpv1-positive) sensory C-fibers derived from vagal ganglia innervate the visceral organs, and respond to inflammatory mediators and noxious stimuli. These neurons play an important role in maintenance of visceral homeostasis, and contribute to the symptoms of visceral inflammatory diseases. Vagal sensory neurons are located in two ganglia, the jugular ganglia (derived from the neural crest), and the nodose ganglia (from the epibranchial placodes). The functional difference, especially in response to immune mediators, between jugular and nodose neurons is not fully understood. In this study, we microscopically isolated murine nodose and jugular capsaicin-sensitive / Trpv1-expressing C-fiber neurons and performed transcriptome profiling using ultra-low input RNA sequencing.
Project description:Vagal afferent neurons are thought to convey primarily physiological information, whereas spinal afferents transmit noxious signals from the viscera to the central nervous system. In order to elucidate molecular identities for these different properties, we compared gene expression profiles of neurons located in nodose ganglia (NG) and dorsal root ganglia (DRG) in mice. Intraperitoneal administration of Alexa Fluor-488 conjugated Cholera toxin B allowed identification of neurons projecting to the viscera. Fluorescent neurons in DRG (from T10 to T13) and NG were isolated using laser capture microdissection. Gene expression profiles of visceral afferent neurons, obtained by microarray hybridization, were analysed using multivariate spectral map analysis, SAM algorithm (Significance Analysis of Microarray data) and fold-difference filtering. A total of 1996 genes were found to be differentially expressed in DRG versus NG, including 41 G-protein coupled receptors and 60 ion channels. Expression profiles obtained on laser-captured neurons were contrasted to those obtained on whole ganglia demonstrating striking differences and the need for microdissection when studying visceral sensory neurons because of dilution of the signal by somatic sensory neurons. Furthermore, a detailed catalogue of all adrenergic and cholinergic, GABA, glutamate, serotonin and dopamine receptors, voltage-gated potassium, sodium and calcium channels and transient receptor potential cation channels present in visceral afferents is provided. Our genome-wide expression profiling data provide novel insight into molecular signatures that underlie both functional differences and similarities between NG and DRG visceral sensory neurons. Moreover, these findings will offer novel insight into mode of action of pharmacologic agents modulating visceral sensation. Keywords: Cell type comparison
Project description:The goal of this study was to analyze global gene expression in specific populations of nociceptor sensory neurons, the neurons that detect damaging/noxious stimuli. The dorsal root ganglia (DRG), trigeminal ganglia, and nodose ganglia are anatomically distinct peripheral sensory ganglia that contain nociceptors which innervate skin, gut, lungs, and other distinct organ tissues. We used flow cytometry to purify nociceptors from these ganglia and profiled their global gene expression signatures to compare gene expression between these different anatomically distinct nociceptors. Nav1.8-Cre were bred with Rosa26-TdTomato to generate Nav1.8-Cre/R26-TdTomato reporter progeny, where all peripheral nociceptor neurons are genetically marked with red fluroescence due to specific expression of the TTX- resistant sodium channel Nav1.8. Lumbar region dorsal root ganglia (DRG), trigeminal ganglia, and nodose ganglia were dissected from mice (3 mice were pooled/sample). Highly red fluorescent neurons were Facs purified, RNA extracted, and processed for microarray analysis.
Project description:The vagus nerves are important carriers of sensory information from the viscera to the central nervous system. Emerging evidence suggests that sensory signaling through the right, but not the left, vagus nerve evokes striatal dopamine release and reinforces appetitive behaviors. However, the extent to which differential gene expression within vagal sensory neurons contributes to this asymmetric reward-related signaling remains unknown. Here, we use single-cell RNA sequencing to identify genes that are differentially expressed between the left and right nodose ganglia (NG) to identify candidate genes likely to contribute to vagus-mediated reward signaling. We find that a group of neurons expressing Chrna3 (nicotinic acetylcholine receptor subunit 3) and Cckar (cholecystokinin A receptor) is preferentially expressed in the right NG of both rats and mice. This result suggests that differential expression of gut-innervating nutrient sensors in NG neurons may contribute to asymmetric encoding of interoceptive rewards by the vagus nerves.