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Dourson, A.

Publications and source records attributed to Dourson, A..

4 recordsLinked to original sources

Preferential innervation of endometriosis by hyperexcitable Ret/GFRα1+ nociceptors associates with target GDNF and clinical pain

Endometriosis is a prevalent condition characterized by chronic pelvic pain that is frequently refractory to treatment. While the mechanisms underlying this pain remain poorly defined, clinical evidence often indicates that lesion innervation, but not disease stage (e.g. number and depth of lesions), correlate with pelvic pain severity. However, characterization of lesion-innervating neurons is incomplete, revealing an opportunity to identify novel, disease-modifying therapeutics. Here, we coupled functional analyses of lesion-innervating neurons in a mouse model with concurrent identification and characterization of lesion-innervating neurons from pain-phenotyped endometriosis patients. Following the confirmation of abdominal-directed pain-like behaviors in the mouse model, electrophysiological analysis revealed that lesion-innervating dorsal root ganglion (DRG) neurons are hyperexcitable compared to matched controls. These neurons are predominantly small-diameter and bind Isolectin B4, an established marker of the GDNF Family Ligand receptor, Ret. GDNF is concentrated within the stromal layer of both mouse and human lesions, adjacent to axons expressing the GDNF co-receptor, GFR1. Critically, clinical pain correlates with lesion GDNF level, axonal density, and neuronal GFR1 levels. These data provide evidence that endometrial lesions may recruit the Ret-positive subpopulation of nociceptors where they become sensitized and increase patient pain.

neuroscience↗

The Critical Role of Pdyn-Lineage Enteric Neurons in Colonic Motility and Visceral Interoception

Summary/Abstract Sensory neurons play well defined roles in the regulation of intestinal motility, digestion, and interoception, but transcriptional dissection of intrinsic and extrinsic sensory neurons innervating the intestines has been challenging because these cells share many genetic markers. However, we cross-referenced transcriptional profiles of intrinsic and extrinsic intestinal neurons and the cells that surround them and identified Pdyn, the gene encoding Prodynorphin, as a marker of putative sensory enteric neurons of the mouse intestines. In a Pdyn lineage-reporter mouse, we identified labeled cells in the myenteric and submucosal plexuses of the large intestine, in contrast to their sparse presence in the dorsal root or nodose ganglia. In dissociated cell culture, these neurons mostly display a phasic firing pattern, discharging one or two action potentials at the onset of a depolarizing current pulse, followed by a prompt cessation of firing despite continued current injection, as assessed by whole-cell patch-clamp recordings. Optogenetic activation of Pdyn-lineage neurons propels stool in ex vivo colons, and in untethered and mobile mice, optogenetic stimulation of the proximal colon induces freezing behaviors and orbital tightening, suggesting interoceptive behaviors, without significant stool output differences. Together, these findings suggest that activation of Pdyn-lineage enteric neurons regulates motility and visceral interoception.

neuroscience↗

A Reference Atlas of the Human Dorsal Root Ganglion

Somatosensory perception largely emerges from diverse peripheral sensory neurons whose cell bodies reside in dorsal root ganglia (DRG). Damage or dysfunction of DRG neurons is a major cause of chronic pain and sensory loss. In mice, deep single-cell transcriptomic profiling and genetically defined models have offered important clues into DRG function, but in humans, the cellular and molecular landscape of DRG neurons remains less understood. Here, we constructed a reference cell atlas of the human DRG by profiling transcriptomes of cells and nuclei from 126 donors sampled across cervical, thoracic, and lumbar DRGs. This atlas resolves 22 neuronal subtypes, including known and previously unrecognized subtypes linked to nociception, mechanosensation, thermosensation, and proprioception, as well as 10 types of non-neuronal cells. Cross-species integration, spatial transcriptomics, and microneurography enabled cell-type-specific comparisons of soma size and conduction velocity between species. Human DRG somata are larger across all cell types than their mouse counterparts, and the conduction velocities of human hair follicle innervating A-fibers are faster than in mice, suggesting a functional shift in rapid mechanical detection in humans. This integrated human DRG reference cell atlas provides a resource for exploring new molecular and physiological features of human DRG, which could help identify new strategies for treating chronic pain and other diseases of the peripheral nervous system.

neuroscience↗

Single nucleus multiomic atlas of human dorsal root ganglia reveals the contribution of non-neuronal cell types to pain

Sensory neurons residing in dorsal root ganglia (DRG) transmit sensory information such as pain, itch, touch, pressure and bodily position to the central nervous system. The activity of sensory neurons is regulated by non-neuronal cell types in the DRG, including satellite glial cells (SGCs), immune cells and fibroblasts. Dysregulated gene expression in DRG cells contributes to sensory nervous system disorders such as chronic pain. Understanding the genetic underpinnings of these conditions requires dissecting transcriptional regulation in human tissue. In this study, we profiled transcriptomic and chromatin accessibility landscapes from postmortem human DRG (hDRG) samples at single-nucleus level. We demonstrate that sequencing depth significantly impacts downstream analysis, with deeper sequencing yielding more detected cells and features, improved data integration, refined clustering and annotation, and more accurate scientific interpretations. We identified nine major cell types, defined their molecular signatures, and mapped cis-regulatory landscapes. Integration of gene expression with chromatin accessibility enabled peak-gene association and transcriptional network analyses, revealing transcription factors, their target genes, regulatory elements and potential partners that cooperatively drive cell-type-specific gene expression programs. This integrative approach identified cell types, genes, and cis-regulatory regions potentially driving pain conditions. Our unbiased genome-wide analysis not only recovered known pain-related genes but also highlighted novel candidate genes and regulatory regions implicated in pain mechanisms. Importantly, our results demonstrate that non-neuronal cells, including endothelial cells, fibroblasts, macrophages, and SGCs, play critical roles in pain pathogenesis and should be investigated as therapeutic targets. One Sentence SummaryOur work provides a comprehensive single-nucleus multi-omic atlas of human dorsal root ganglia, uncovering novel cell-type-specific regulatory mechanisms and candidate therapeutic targets for pain, thereby directly advancing translational insights into human sensory disorders and chronic pain pathogenesis.

neuroscience↗