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FEBS Letters Mar 2022Exosomes, nano-sized extracellular vesicles, are produced via the endosomal pathway and released in the extracellular space upon fusion of multivesicular bodies with the... (Review)
Review
Exosomes, nano-sized extracellular vesicles, are produced via the endosomal pathway and released in the extracellular space upon fusion of multivesicular bodies with the plasma membrane. Recent evidence shows that these extracellular vesicles play a key role in cell-to-cell communication. Exosomes transport bioactive proteins, mRNAs, and microRNA (miRNAs) in an active form to adjacent cells or to distant organs. In this review, we focus on the role of exosomes in peripheral nerve maintenance and repair, as well as peripheral nerve/organ crosstalk, and discuss the potential benefits of exploiting exosomes for treating PNS injuries. In addition, we will highlight the emerging role of exosomes as new important vehicles for physiological systemic crosstalk failures, which could lead to organ dysfunction during neuroinflammation or aging.
Topics: Cell Communication; Exosomes; Extracellular Vesicles; MicroRNAs; Peripheral Nervous System
PubMed: 34990014
DOI: 10.1002/1873-3468.14274 -
NeuroImage Jan 2021The emergence of diffusion, structural, and functional neuroimaging methods has enabled major multi-site efforts to map the human connectome, which has heretofore been... (Review)
Review
The emergence of diffusion, structural, and functional neuroimaging methods has enabled major multi-site efforts to map the human connectome, which has heretofore been defined as containing all neural connections in the central nervous system (CNS). However, these efforts are not structured to examine the richness and complexity of the peripheral nervous system (PNS), which arguably forms the (neglected) rest of the connectome. Despite increasing interest in an atlas of the spinal cord (SC) and PNS which is simultaneously stereotactic, interactive, electronically dissectible, scalable, population-based and deformable, little attention has thus far been devoted to this task of critical importance. Nevertheless, the atlasing of these complete neural structures is essential for neurosurgical planning, neurological localization, and for mapping those components of the human connectome located outside of the CNS. Here we recommend a modification to the definition of the human connectome to include the SC and PNS, and argue for the creation of an inclusive atlas to complement current efforts to map the brain's human connectome, to enhance clinical education, and to assist progress in neuroscience research. In addition to providing a critical overview of existing neuroimaging techniques, image processing methodologies and algorithmic advances which can be combined for the creation of a full connectome atlas, we outline a blueprint for ultimately mapping the entire human nervous system and, thereby, for filling a critical gap in our scientific knowledge of neural connectivity.
Topics: Connectome; Diffusion Tensor Imaging; Image Processing, Computer-Assisted; Neural Pathways; Neuroimaging; Peripheral Nervous System; Spinal Cord
PubMed: 33160086
DOI: 10.1016/j.neuroimage.2020.117478 -
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 -
Preface: Cholinergic mechanisms: This is the Preface for the special issue "Cholinergic Mechanisms".Journal of Neurochemistry Sep 2021This special issue of the Journal of Neurochemistry, entitled "Cholinergic Mechanisms," presents 15 reviews and two original papers, which have been selected to cover...
This special issue of the Journal of Neurochemistry, entitled "Cholinergic Mechanisms," presents 15 reviews and two original papers, which have been selected to cover the broad spectrum of topics and disciplines presented at the XVIth International Symposium on Cholinergic Mechanisms (ISCM-XVI), ranging from the molecular and the cellular to the clinical and the cognitive mechanisms of cholinergic transmission. The authors discuss recent developments in the field, for instance, the association of cholinergic transmission with a number of important neurological and neuromuscular diseases in the central and peripheral nervous systems.
Topics: Acetylcholine; Animals; Brain; Cholinergic Agents; Cholinergic Neurons; Humans; Peripheral Nervous System; Synaptic Transmission
PubMed: 34458988
DOI: 10.1111/jnc.15480 -
Cold Spring Harbor Perspectives in... Dec 2019The peripheral nervous system (PNS) is highly complicated and heterogenous. Conventional neuromodulatory approaches have revealed numerous essential biological functions... (Review)
Review
The peripheral nervous system (PNS) is highly complicated and heterogenous. Conventional neuromodulatory approaches have revealed numerous essential biological functions of the PNS and provided excellent tools to treat a large variety of human diseases. Yet growing evidence indicated the importance of cell-type-specific neuromodulation in the PNS in not only biological research using animal models but also potential human therapies. Optogenetics is a recently developed neuromodulatory approach combining optics and genetics that can effectively stimulate or silence neuronal activity with high spatial and temporal precision. Here, I review research regarding optogenetic manipulations for cell-type-specific control of the PNS, highlighting the advantages and challenges of current optogenetic tools, and discuss their potential future applications.
Topics: Animals; Animals, Genetically Modified; Humans; Neurons; Optogenetics; Peripheral Nervous System
PubMed: 30745289
DOI: 10.1101/cshperspect.a034397 -
Experimental Neurology May 2010Regeneration in the peripheral nervous system offers unique opportunities and challenges to medicine. Compared to the central nervous system, peripheral axons can and do...
Regeneration in the peripheral nervous system offers unique opportunities and challenges to medicine. Compared to the central nervous system, peripheral axons can and do regenerate resulting in functional recovery, especially if the distance to target is short as in distal limb injuries. However, this regenerative capacity is often incomplete and functional recovery with proximal lesions is limited. Furthermore, regeneration of axons to the appropriate targets remains a challenge with inappropriate reinnervation being an impediment to full recovery. The reviews and selected original research papers in this Special Issue will address some of these challenges and highlight new opportunities for development of effective therapies for nerve regeneration.
Topics: Animals; Axons; Humans; Nerve Regeneration; Peripheral Nervous System; Recovery of Function
PubMed: 20004660
DOI: 10.1016/j.expneurol.2009.12.001 -
The Journal of Investigative... Aug 1997Major advances have been made in our understanding of autonomic and sensory transmission and function during the past two decades. These include (i) the establishment of... (Review)
Review
Major advances have been made in our understanding of autonomic and sensory transmission and function during the past two decades. These include (i) the establishment of the role of sympathetic and parasympathetic ganglia in relaying neuronal information from the central nervous system to effector organs, (ii) the recognition that enteric ganglia, the third component of the autonomic nervous system, contain independent integrative circuits that control complex local activities, (iii) the evidence for local effector functions of primary sensory nerves in addition to their role in sensory transmission, and (iv) the discovery of plasticity of both autonomic and sensory neurons during disease states and inflammation. A major contribution to these new concepts has been the recognition that in both autonomic and sensory ganglia a variety of transmitters coexist in single neurons. Co-transmission is a widespread phenomenon that enables autonomic and sensory neurons to exert fine and highly regulated control of various functions such as circulation, respiration, digestion, and immune response. This chapter will focus on the general principles and specific features of autonomic and sensory ganglia, with a particular emphasis on their general organization and neurochemical properties. Classical concepts and modern principles of classification of autonomic and sensory ganglia are discussed.
Topics: Animals; Autonomic Nervous System; Axons; Ganglia, Autonomic; Ganglia, Sensory; Humans; Neurons; Neurons, Afferent; Peripheral Nervous System
PubMed: 9487007
DOI: 10.1038/jidsymp.1997.2 -
Glia Oct 2020The presence of peripheral myelinating cells in the central nervous system (CNS) has gained the neurobiologist attention over the years. Despite the confirmed presence... (Review)
Review
The presence of peripheral myelinating cells in the central nervous system (CNS) has gained the neurobiologist attention over the years. Despite the confirmed presence of Schwann cells in the CNS in pathological conditions, and the long list of their beneficial effects on central remyelination, the cues that impede or allow Schwann cells to successfully conquer and remyelinate central axons remain partially undiscovered. A better knowledge of these factors stands out as crucial to foresee a rational therapeutic approach for the use of Schwann cells in CNS repair. Here, we review the diverse origins of Schwann cells into the CNS, both peripheral and central, as well as the CNS components that inhibit Schwann survival and migration into the central parenchyma. Namely, we analyze the astrocyte- and the myelin-derived components that restrict Schwann cells into the CNS. Finally, we highlight the unveiled mode of invasion of these peripheral cells through the central environment, using blood vessels as scaffolds to pave their ways toward demyelinated lesions. In short, this review presents the so far uncovered knowledge of this complex CNS-peripheral nervous system (PNS) relationship.
Topics: Animals; Cell Movement; Cell Survival; Central Nervous System; Demyelinating Diseases; Humans; Myelin Sheath; Peripheral Nervous System; Remyelination; Schwann Cells
PubMed: 32027054
DOI: 10.1002/glia.23788 -
ACS Chemical Neuroscience Mar 2021Cytokines and chemokines have diverse and pleiotropic functions in peripheral tissues and in the brain. Recent studies uncovered a novel family of neuron-derived... (Review)
Review
Cytokines and chemokines have diverse and pleiotropic functions in peripheral tissues and in the brain. Recent studies uncovered a novel family of neuron-derived secretory proteins, or neurokines, distantly related to chemokines. The FAM19A family comprises five ∼12-15 kDa secretory proteins (FAM19A1-5), also known as TAFA1-5, that are predominantly detected in the central and peripheral nervous system. expression in the central nervous system is dynamically regulated during development and in the postnatal brain. As secreted ligands, FAM19A proteins appear to bind to different classes of cell surface receptors (e.g., GPCRs and neurexins). Functional studies using gain- and loss-of-function mouse models established nonredundant roles for each FAM19A family member in regulating diverse physiological processes ranging from locomotor activity and food intake to learning and memory, anxiety- and depressive-like behaviors, social communication, repetitive behaviors, and somatosensory functions. This review summarizes major advances as well as the limitations and knowledge gaps in understanding the regulation and diverse biological functions of this conserved family of neurokines.
Topics: Animals; Brain; Central Nervous System; Chemokines; Mice; Neurons; Peripheral Nervous System
PubMed: 33621067
DOI: 10.1021/acschemneuro.0c00757 -
Pain Physician Mar 2008Opioids are broad-spectrum analgesics with potent pain-relieving qualities but also with potential adverse effects related to both short-term and long-term therapy.... (Review)
Review
Opioids are broad-spectrum analgesics with potent pain-relieving qualities but also with potential adverse effects related to both short-term and long-term therapy. Researchers have attempted to alter existing opioid analgesics, utilize different routes/formulations, or combine opioid analgesics with other compounds in efforts to improve analgesia while minimizing adverse effects. Exogenous opioids, administered in efforts to achieve analgesia, work by mimicking the actions of endogenous opioids. Endogenous opioids and their receptors are located in the brain (supraspinal areas), spinal cord, and periphery. Although opioids and opioid receptors in the brain and spinal cord have received much attention over many years, peripheral endogenous opioid analgesic systems have only been extensively studied during the past decade. It has been known since 1990 that following injection into the rodent hindpaw, D-Ala(2),N-Me-Phe(4), Gly(5)-ol-enkephalin (DAMGO) [a muopioid receptor agonist] probably exerts its antinociceptive effects locally, since the doses administered are too low to have an effect in the central nervous system (CNS). This notion has been supported by the observation that the quaternary compound morphine methyliodide, which does not as readily cross the bloodbrain barrier and enter the CNS, produced antinociception following intradermal administration into the hindpaw, but not when the same dose was administered systemically (subcutaneously at a distant site). With a growing appreciation of peripheral endogenous opioids, peripheral endogenous opioid receptors, and peripheral endogenous opioid analgesic systems, investigators began growing hopeful that it may be possible to achieve adequate analgesics while avoiding unwanted central untoward adverse effects (e.g. respiratory depression, somnolence, addiction). Peripherally-acting opioids, which capitalize on peripheral endogenous opioid analgesic systems, may be one potential future strategy which may be utilized in efforts to achieve potent analgesia with minimal side effects.
Topics: Analgesics, Opioid; Enkephalin, Ala(2)-MePhe(4)-Gly(5)-; Humans; Inflammation; Leukocytes; Pain; Peripheral Nervous System
PubMed: 18443636
DOI: No ID Found