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Romanian Journal of Morphology and... 2022In this paper, we developed the hypothesis concerning the reasons to assimilate endoneurial fibroblast-like dendritic phenotype [shortly termed endoneurial dendritic... (Review)
Review
In this paper, we developed the hypothesis concerning the reasons to assimilate endoneurial fibroblast-like dendritic phenotype [shortly termed endoneurial dendritic cells (EDCs)] to the endoneurial telocytes (TCs). We reviewed the literature concerning EDCs status and report our observations on ultrastructure and some immune electron microscopic aspects of the cutaneous peripheral nerves. Our data demonstrate that EDCs long time considered as fibroblasts or fibroblast-like, with an ovoidal nucleus and one or more moniliform cell extensions [telopodes (Tps)], which perform homocellular junctions, also able to shed extracellular microvesicles can be assimilated to TC phenotype. Sometimes, small profiles of basement membrane accompany to some extent Tps. Altogether data resulted from scientific literature and our results strength the conclusion EDCs are really TCs inside of the peripheral nervous system. The inner three-dimensional (3D) network of endoneurial TCs by their homo- and heterocellular communications appears as a genuine cell-to-cell communication system inside of each peripheral nerve.
Topics: Telocytes; Cell Communication; Fibroblasts; Peripheral Nervous System; Peripheral Nerves
PubMed: 36374139
DOI: 10.47162/RJME.63.2.05 -
Toxicologic Pathology Jan 2020Qualitative histopathology has been the gold standard for evaluation of morphological tissue changes in all organ systems, including the peripheral nervous system....
Qualitative histopathology has been the gold standard for evaluation of morphological tissue changes in all organ systems, including the peripheral nervous system. However, the human eye is not sensitive enough to detect small changes in quantity or size. Peripheral nervous system toxicity can manifest as subtle changes in neuron size, neuron number, axon size, number of myelinated or unmyelinated axons, or number of nerve fibers. Detection of these changes may be beyond the sensitivity of the human eye alone, necessitating quantitative approaches in some cases. Although 2-dimensional (2D) histomorphometry can provide additional information and is more sensitive than qualitative evaluation alone, the results are not always representative of the entire tissue and assumptions about the tissue can lead to bias, or inaccuracies, in the data. Design-based stereology provides 3D estimates of number, volume, surface area, or length, and stereological principles can be applied to peripheral nervous system tissues to obtain accurate and precise estimates, such as neuron number and size, axon number, and total intraepidermal nerve fiber length. This review describes practical stereological approaches to 3 compartments of the peripheral nervous system: ganglia, peripheral nerves, and intraepidermal nerve fibers.
Topics: Animals; Axons; Humans; Myelin Sheath; Nerve Fibers; Peripheral Nervous System; Toxicology
PubMed: 31221020
DOI: 10.1177/0192623319854746 -
Frontiers in Immunology 2021The peripheral nervous system consists of sensory circuits that respond to external and internal stimuli and effector circuits that adapt physiologic functions to... (Review)
Review
The peripheral nervous system consists of sensory circuits that respond to external and internal stimuli and effector circuits that adapt physiologic functions to environmental challenges. Identifying neurotransmitters and neuropeptides and the corresponding receptors on immune cells implies an essential role for the nervous system in regulating immune reactions. Vice versa, neurons express functional cytokine receptors to respond to inflammatory signals directly. Recent advances in single-cell and single-nuclei sequencing have provided an unprecedented depth in neuronal analysis and allowed to refine the classification of distinct neuronal subsets of the peripheral nervous system. Delineating the sensory and immunoregulatory capacity of different neuronal subsets could inform a better understanding of the response happening in tissues that coordinate physiologic functions, tissue homeostasis and immunity. Here, we summarize current subsets of peripheral neurons and discuss neuronal regulation of immune responses, focusing on neuro-immune interactions in the gastrointestinal tract. The nervous system as a central coordinator of immune reactions and tissue homeostasis may predispose for novel promising therapeutic approaches for a large variety of diseases including but not limited to chronic inflammation.
Topics: Animals; Biomarkers; Disease Susceptibility; Gene Expression Regulation; Humans; Immunomodulation; Neuroimmunomodulation; Neurons; Peripheral Nervous System; Signal Transduction
PubMed: 34322118
DOI: 10.3389/fimmu.2021.679055 -
Journal of Neural Engineering Jul 2022The nervous system, through a combination of conscious and automatic processes, enables the regulation of the body and its interactions with the environment. The... (Review)
Review
The nervous system, through a combination of conscious and automatic processes, enables the regulation of the body and its interactions with the environment. The peripheral nervous system is an excellent target for technologies that seek to modulate, restore or enhance these abilities as it carries sensory and motor information that most directly relates to a target organ or function. However, many applications require a combination of both an effective peripheral nerve interface (PNI) and effective signal processing techniques to provide selective and stable recordings. While there are many reviews on the design of PNIs, reviews of data analysis techniques and translational considerations are limited. Thus, this tutorial aims to support new and existing researchers in the understanding of the general guiding principles, and introduces a taxonomy for electrode configurations, techniques and translational models to consider.
Topics: Electrodes, Implanted; Peripheral Nerves; Peripheral Nervous System; Signal Processing, Computer-Assisted
PubMed: 35772397
DOI: 10.1088/1741-2552/ac7d74 -
Trends in Immunology Dec 2018Relentless, repetitive itching and scratching is a debilitating feature of many chronic inflammatory skin disorders such as atopic dermatitis. While well known... (Review)
Review
Relentless, repetitive itching and scratching is a debilitating feature of many chronic inflammatory skin disorders such as atopic dermatitis. While well known clinically, this itch-scratch cycle has historically lacked in-depth mechanistic understanding. However, recent advances at the interface of itch neurobiology and skin immunology have shed new light on this phenomenon. In this review, we highlight recent advances in our understanding of the neuroimmunology of chronic itch centered around three key points of entry into the itch-scratch cycle: the epithelial barrier, the immune system, and the peripheral nervous system. Furthermore, we explore novel neuro-epithelial-immune interactions that may represent promising therapeutic paradigms.
Topics: Animals; Humans; Peripheral Nervous System; Pruritus
PubMed: 30471983
DOI: 10.1016/j.it.2018.10.001 -
Current Opinion in Neurology Oct 2006The aim of this review is to describe the local immune circuitry in the peripheral nervous system and its dialogue with systemic immunity under pathological conditions.... (Review)
Review
PURPOSE OF REVIEW
The aim of this review is to describe the local immune circuitry in the peripheral nervous system and its dialogue with systemic immunity under pathological conditions. Specifically, interactions of the immune system with cellular and extracellular components within peripheral nerve and immune functions of tissue-resident endoneurial macrophages and Schwann cells will be discussed.
RECENT FINDINGS
New insights into the elements involved in the pathogenesis of immune-mediated disorders of the peripheral nervous system provide a better understanding of the complex interplay of these cellular and molecular components in the immunology of the peripheral nervous system.
SUMMARY
The application of innovative and cutting-edge technologies to the study of immunoinflammatory disorders of the peripheral nervous system provides a better understanding of underlying principles of the organization of the immune network present in the peripheral nerve and its dialogue with the systemic immune system. This may foster the development of specific and highly effective therapies for immune-mediated disorders of the peripheral nerve.
Topics: Animals; Antibody Formation; B-Lymphocytes; Humans; Immune System; Immune System Diseases; Models, Immunological; Peripheral Nervous System; Peripheral Nervous System Diseases; Schwann Cells; T-Lymphocytes
PubMed: 16969152
DOI: 10.1097/01.wco.0000245365.51823.72 -
Physical Medicine and Rehabilitation... May 2001This article is an overview of the structure and components of the peripheral nervous system. The fine structure and gross anatomy of peripheral nerves and ganglia are... (Review)
Review
This article is an overview of the structure and components of the peripheral nervous system. The fine structure and gross anatomy of peripheral nerves and ganglia are described. A functional and regional approach is used to highlight principles on which the peripheral nervous system is designed. Finally, the somatic and autonomic nervous systems are contrasted to underscore similarities between the two systems.
Topics: Autonomic Nervous System; Humans; Parasympathetic Nervous System; Peripheral Nervous System; Sympathetic Nervous System
PubMed: 11345004
DOI: No ID Found -
Annual Review of Physiology 2010Most physiology and behavior of mammalian organisms follow daily oscillations. These rhythmic processes are governed by environmental cues (e.g., fluctuations in light... (Review)
Review
Most physiology and behavior of mammalian organisms follow daily oscillations. These rhythmic processes are governed by environmental cues (e.g., fluctuations in light intensity and temperature), an internal circadian timing system, and the interaction between this timekeeping system and environmental signals. In mammals, the circadian timekeeping system has a complex architecture, composed of a central pacemaker in the brain's suprachiasmatic nuclei (SCN) and subsidiary clocks in nearly every body cell. The central clock is synchronized to geophysical time mainly via photic cues perceived by the retina and transmitted by electrical signals to SCN neurons. In turn, the SCN influences circadian physiology and behavior via neuronal and humoral cues and via the synchronization of local oscillators that are operative in the cells of most organs and tissues. Thus, some of the SCN output pathways serve as input pathways for peripheral tissues. Here we discuss knowledge acquired during the past few years on the complex structure and function of the mammalian circadian timing system.
Topics: Animals; Biological Clocks; Brain; Central Nervous System; Circadian Rhythm; Food; Humans; Peripheral Nervous System; Reinforcement, Psychology; Reward; Suprachiasmatic Nucleus
PubMed: 20148687
DOI: 10.1146/annurev-physiol-021909-135821 -
Toxicologic Pathology Jan 2011This article is from a presentation at the 2010 STP/IFSTP Symposium on Neuropathology. The organization and basic structure of the peripheral nervous system is reviewed.... (Review)
Review
This article is from a presentation at the 2010 STP/IFSTP Symposium on Neuropathology. The organization and basic structure of the peripheral nervous system is reviewed. Examples of toxicant-induced peripheral nerve injury such as neuronopathy, axonopathy, and myelinapathy are discussed, as are contemporary methods for examination of these tissues.
Topics: Animals; Axons; Humans; Nerve Degeneration; Nervous System Diseases; Neurotoxicity Syndromes; Peripheral Nervous System; Peripheral Nervous System Diseases; Specimen Handling; Staining and Labeling; Trauma, Nervous System
PubMed: 21078921
DOI: 10.1177/0192623310387618 -
Current Topics in Developmental Biology 2020Sensory placodes and neural crest cells are among the key cell populations that facilitated the emergence and diversification of vertebrates throughout evolution.... (Review)
Review
Sensory placodes and neural crest cells are among the key cell populations that facilitated the emergence and diversification of vertebrates throughout evolution. Together, they generate the sensory nervous system in the head: both form the cranial sensory ganglia, while placodal cells make major contributions to the sense organs-the eye, ear and olfactory epithelium. Both are instrumental for integrating craniofacial organs and have been key to drive the concentration of sensory structures in the vertebrate head allowing the emergence of active and predatory life forms. Whereas the gene regulatory networks that control neural crest cell development have been studied extensively, the signals and downstream transcriptional events that regulate placode formation and diversity are only beginning to be uncovered. Both cell populations are derived from the embryonic ectoderm, which also generates the central nervous system and the epidermis, and recent evidence suggests that their initial specification involves a common molecular mechanism before definitive neural, neural crest and placodal lineages are established. In this review, we will first discuss the transcriptional networks that pattern the embryonic ectoderm and establish these three cell fates with emphasis on sensory placodes. Second, we will focus on how sensory placode precursors diversify using the specification of otic-epibranchial progenitors and their segregation as an example.
Topics: Animals; Cell Differentiation; Ectoderm; Gene Expression Regulation, Developmental; Gene Regulatory Networks; Head; Humans; Neural Crest; Peripheral Nervous System; Vertebrates
PubMed: 32450959
DOI: 10.1016/bs.ctdb.2020.04.002