scholarly journals Glial ensheathment of the somatodendritic compartment regulates sensory neuron structure and activity

2019 ◽  
Vol 116 (11) ◽  
pp. 5126-5134 ◽  
Author(s):  
Smita Yadav ◽  
Susan H. Younger ◽  
Linghua Zhang ◽  
Katherine L. Thompson-Peer ◽  
Tun Li ◽  
...  
Keyword(s):  
Sensory Neuron ◽  
Sensory Neurons ◽  
Cell Types ◽  
Environmental Cues ◽  
Sensory Stimuli ◽  
Neuronal Soma ◽  
Selective Elimination ◽  
Light Stimuli ◽  
Peripheral Sensory ◽  
Structure And Activity

Sensory neurons perceive environmental cues and are important of organismal survival. Peripheral sensory neurons interact intimately with glial cells. While the function of axonal ensheathment by glia is well studied, less is known about the functional significance of glial interaction with the somatodendritic compartment of neurons. Herein, we show that three distinct glia cell types differentially wrap around the axonal and somatodendritic surface of the polymodal dendritic arborization (da) neuron of the Drosophila peripheral nervous system for detection of thermal, mechanical, and light stimuli. We find that glial cell-specific loss of the chromatin modifier gene dATRX in the subperineurial glial layer leads to selective elimination of somatodendritic glial ensheathment, thus allowing us to investigate the function of such ensheathment. We find that somatodendritic glial ensheathment regulates the morphology of the dendritic arbor, as well as the activity of the sensory neuron, in response to sensory stimuli. Additionally, glial ensheathment of the neuronal soma influences dendritic regeneration after injury.

scholarly journals Aversive Learning Increases Release Probability of Olfactory Sensory Neurons

2019 ◽  
Author(s):  
Janardhan P. Bhattarai ◽  
Mary Schreck ◽  
Andrew H. Moberly ◽  
Wenqin Luo ◽  
Minghong Ma
Keyword(s):  
Sensory Neurons ◽  
Receptor Expression ◽  
Olfactory Sensory Neurons ◽  
Aversive Learning ◽  
Sensory Stimuli ◽  
Release Probability ◽  
Synaptic Release ◽  
Underlying Mechanisms ◽  
Peripheral Sensory ◽  
Cortical Influence

AbstractPredicting danger from previously associated sensory stimuli is essential for survival. Contributions from altered peripheral sensory inputs are implicated in this process, but the underlying mechanisms remain elusive. Here we use the mammalian olfactory system to investigate such mechanisms. Primary olfactory sensory neurons (OSNs) project their axons directly to the olfactory bulb (OB) glomeruli where their synaptic release is subject to local and cortical influence and neuromodulation. Pairing optogenetic activation of a single glomerulus with foot shock in mice induces freezing to the light stimulation alone during fear retrieval. This is accompanied by an increase in OSN release probability and a reduction in GABAB receptor expression in the conditioned glomerulus. Furthermore, freezing time is positively correlated with the release probability of OSNs in fear conditioned mice. These results suggest that aversive learning increases peripheral olfactory inputs at the first synapse, which may contribute to the behavioral outcome.

CGRP-immunoreactive cells supplying laryngeal sensory nerve fibres in the cat's nodose ganglion

1993 ◽  
Vol 107 (10) ◽  
pp. 916-919 ◽  
Author(s):  
Yasumusa Tanaka ◽  
Yoshikazu Yoshida ◽  
Minoru Hirano
Keyword(s):  
Sensory Neuron ◽  
Sensory Neurons ◽  
Sensory Nerve ◽  
Middle Part ◽  
Nodose Ganglion ◽  
Sensory Innervation ◽  
Sensory Cells ◽  
Laryngeal Mucosa ◽  
Peripheral Sensory ◽  
Rostral Part

AbstractThrough a combination of retrograde staining by wheat germ agglutinin (WGA) and immunohistochemistry, calcitonin gene-related peptide (CGRP)-reactive sensory neurons projecting from the laryngeal mucosa were detected in the feline nodose ganglion. The size of the CGRP-immunoreactive cell which was regarded as a laryngeal sensory neuron, was about 60 ±m in diameter: the shape of the immunoreactive laryngeal sensory neuron was unipolar. CGRP-reacted laryngeal sensory cells were found in the rostral part of the nodose ganglion extending to the middle part. They aggregated in the most rostral part, were sparse in other parts and were approximately 50 per cent of WGA-reactive laryngeal sensory neurons in number. Our results suggest that this neurotransmitter might play an important role in laryngeal peripheral sensory innervation.

scholarly journals Single cell transcriptomics of primate sensory neurons identifies cell types associated with chronic pain

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jussi Kupari ◽  
Dmitry Usoskin ◽  
Marc Parisien ◽  
Daohua Lou ◽  
Yizhou Hu ◽  
...  
Keyword(s):  
Chronic Pain ◽  
Dorsal Root Ganglion ◽  
Sensory Neuron ◽  
Sensory Neurons ◽  
Dorsal Root ◽  
Species Conservation ◽  
Cell Types ◽  
Individual Gene ◽  
Cellular Origin ◽  
Neuronal Types

AbstractDistinct types of dorsal root ganglion sensory neurons may have unique contributions to chronic pain. Identification of primate sensory neuron types is critical for understanding the cellular origin and heritability of chronic pain. However, molecular insights into the primate sensory neurons are missing. Here we classify non-human primate dorsal root ganglion sensory neurons based on their transcriptome and map human pain heritability to neuronal types. First, we identified cell correlates between two major datasets for mouse sensory neuron types. Machine learning exposes an overall cross-species conservation of somatosensory neurons between primate and mouse, although with differences at individual gene level, highlighting the importance of primate data for clinical translation. We map genomic loci associated with chronic pain in human onto primate sensory neuron types to identify the cellular origin of chronic pain. Genome-wide associations for chronic pain converge on two different neuronal types distributed between pain disorders that display different genetic susceptibilities, suggesting both unique and shared mechanisms between different pain conditions.

scholarly journals The Role of Voltage-Gated Sodium Channels in Pain Signaling

2019 ◽  
Vol 99 (2) ◽  
pp. 1079-1151 ◽  
Author(s):  
David L. Bennett ◽  
Alex J. Clark ◽  
Jianying Huang ◽  
Stephen G. Waxman ◽  
Sulayman D. Dib-Hajj
Keyword(s):  
Chronic Pain ◽  
Sodium Channels ◽  
Sensory Neuron ◽  
Sensory Neurons ◽  
Expression Patterns ◽  
Sensory Transduction ◽  
Gene Variants ◽  
Sensory Stimuli ◽  
Voltage Gated ◽  
Voltage Gated Sodium Channels

Acute pain signaling has a key protective role and is highly evolutionarily conserved. Chronic pain, however, is maladaptive, occurring as a consequence of injury and disease, and is associated with sensitization of the somatosensory nervous system. Primary sensory neurons are involved in both of these processes, and the recent advances in understanding sensory transduction and human genetics are the focus of this review. Voltage-gated sodium channels (VGSCs) are important determinants of sensory neuron excitability: they are essential for the initial transduction of sensory stimuli, the electrogenesis of the action potential, and neurotransmitter release from sensory neuron terminals. Nav1.1, Nav1.6, Nav1.7, Nav1.8, and Nav1.9 are all expressed by adult sensory neurons. The biophysical characteristics of these channels, as well as their unique expression patterns within subtypes of sensory neurons, define their functional role in pain signaling. Changes in the expression of VGSCs, as well as posttranslational modifications, contribute to the sensitization of sensory neurons in chronic pain states. Furthermore, gene variants in Nav1.7, Nav1.8, and Nav1.9 have now been linked to human Mendelian pain disorders and more recently to common pain disorders such as small-fiber neuropathy. Chronic pain affects one in five of the general population. Given the poor efficacy of current analgesics, the selective expression of particular VGSCs in sensory neurons makes these attractive targets for drug discovery. The increasing availability of gene sequencing, combined with structural modeling and electrophysiological analysis of gene variants, also provides the opportunity to better target existing therapies in a personalized manner.

scholarly journals Hyperexcitability of Sensory Neurons in Fragile X Mouse Model

2021 ◽  
Vol 14 ◽  
Author(s):  
Pan-Yue Deng ◽  
Oshri Avraham ◽  
Valeria Cavalli ◽  
Vitaly A. Klyachko
Keyword(s):  
Mouse Model ◽  
Sensory Neuron ◽  
Sensory Neurons ◽  
Fragile X ◽  
Input Resistance ◽  
Resting Membrane Potential ◽  
Hcn Channels ◽  
Satellite Glial Cells ◽  
Peripheral Sensory Neurons ◽  
Peripheral Sensory

Sensory hypersensitivity and somatosensory deficits represent the core symptoms of Fragile X syndrome (FXS). These alterations are believed to arise from changes in cortical sensory processing, while potential deficits in the function of peripheral sensory neurons residing in dorsal root ganglia remain unexplored. We found that peripheral sensory neurons exhibit pronounced hyperexcitability in Fmr1 KO mice, manifested by markedly increased action potential (AP) firing rate and decreased threshold. Unlike excitability changes found in many central neurons, no significant changes were observed in AP rising and falling time, peak potential, amplitude, or duration. Sensory neuron hyperexcitability was caused primarily by increased input resistance, without changes in cell capacitance or resting membrane potential. Analyses of the underlying mechanisms revealed reduced activity of HCN channels and reduced expression of HCN1 and HCN4 in Fmr1 KO compared to WT. A selective HCN channel blocker abolished differences in all measures of sensory neuron excitability between WT and Fmr1 KO neurons. These results reveal a hyperexcitable state of peripheral sensory neurons in Fmr1 KO mice caused by dysfunction of HCN channels. In addition to the intrinsic neuronal dysfunction, the accompanying paper examines deficits in sensory neuron association/communication with their enveloping satellite glial cells, suggesting contributions from both neuronal intrinsic and extrinsic mechanisms to sensory dysfunction in the FXS mouse model.

scholarly journals Disrupted Association of Sensory Neurons With Enveloping Satellite Glial Cells in Fragile X Mouse Model

2022 ◽  
Vol 14 ◽  
Author(s):  
Oshri Avraham ◽  
Pan-Yue Deng ◽  
Dario Maschi ◽  
Vitaly A. Klyachko ◽  
Valeria Cavalli
Keyword(s):  
Sensory Neuron ◽  
Glial Cells ◽  
Fragile X ◽  
Sensory System ◽  
Structural Defects ◽  
Learning Networks ◽  
Sensory Stimuli ◽  
Satellite Glial Cells ◽  
Sensory Deficits ◽  
Peripheral Sensory

Among most prevalent deficits in individuals with Fragile X syndrome (FXS) is hypersensitivity to sensory stimuli and somatosensory alterations. Whether dysfunction in peripheral sensory system contributes to these deficits remains poorly understood. Satellite glial cells (SGCs), which envelop sensory neuron soma, play critical roles in regulating neuronal function and excitability. The potential contributions of SGCs to sensory deficits in FXS remain unexplored. Here we found major structural defects in sensory neuron-SGC association in the dorsal root ganglia (DRG), manifested by aberrant covering of the neuron and gaps between SGCs and the neuron along their contact surface. Single-cell RNAseq analyses demonstrated transcriptional changes in both neurons and SGCs, indicative of defects in neuronal maturation and altered SGC vesicular secretion. We validated these changes using fluorescence microscopy, qPCR, and high-resolution transmission electron microscopy (TEM) in combination with computational analyses using deep learning networks. These results revealed a disrupted neuron-glia association at the structural and functional levels. Given the well-established role for SGCs in regulating sensory neuron function, altered neuron-glia association may contribute to sensory deficits in FXS.

scholarly journals Single cell transcriptomics of primate sensory neurons identifies cell types associated with human chronic pain

2020 ◽  
Author(s):  
Jussi Kupari ◽  
Dmitry Usoskin ◽  
Daohua Lou ◽  
Marc Parisien ◽  
Yizhou Hu ◽  
...  
Keyword(s):  
Chronic Pain ◽  
Dorsal Root Ganglion ◽  
Sensory Neuron ◽  
Sensory Neurons ◽  
Dorsal Root ◽  
Species Conservation ◽  
Cell Types ◽  
Individual Gene ◽  
Cellular Origin ◽  
Neuronal Types

AbstractDistinct types of dorsal root ganglion sensory neurons may have unique contributions to chronic pain. Identification of primate sensory neuron types is critical for understanding the cellular origin and heritability of chronic pain. However, molecular insights into the primate sensory neurons are missing. Here we classify non-human primate dorsal root ganglion sensory neurons based on their transcriptome and map human pain heritability to neuronal types. First, we identified cell correlates between two major datasets for mouse sensory neuron types. Machine learning exposes an overall cross-species conservation of somatosensory neurons between primate and mouse, although with differences at individual gene level, highlighting the importance of primate data for clinical translation. We map genomic loci associated with chronic pain in human onto primate sensory neuron types to identify the cellular origin of human chronic pain. Genome-wide associations for chronic pain converge on two different neuronal types distributed between pain disorders that display different genetic susceptibilities, suggesting both unique and shared mechanisms between different pain conditions.

Correlative transmission and high-resolution scanning electron microscopic studies on pituitary cells

1990 ◽  
Vol 48 (3) ◽  
pp. 20-21
Author(s):  
S. Tai
Keyword(s):  
Cell Types ◽  
Depth Of Field ◽  
Secretory Cells ◽  
Specific Cell ◽  
Pituitary Cells ◽  
Electron Microscopic ◽  
3 Dimensional ◽  
Microscopic Studies ◽  
Structure And Activity ◽  
Intracellular Structure

Extensive cytological and histological research, correlated with physiological experimental analysis, have been done on the anterior pituitaries of many different vertebrates which have provided the knowledge to create the concept that specific cell types synthesize, store and release their specific hormones. These hormones are stored in or associated with granules. Nevertheless, there are still many doubts - that need further studies, specially on the ultrastructure and physiology of these endocrine cells during the process of synthesis, transport and secretion, whereas some new methods may provide the information about the intracellular structure and activity in detail.In the present work, ultrastructural study of the hormone-secretory cells of chicken pituitaries have been done by using TEM as well as HR-SEM, to correlate the informations obtained from 2-dimensional TEM micrography with the 3-dimensional SEM topographic images, which have a continous surface with larger depth of field that - offers the adventage to interpretate some intracellular structures which were not possible to see using TEM.

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