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1.
Epigenetics Chromatin ; 17(1): 14, 2024 May 07.
Article En | MEDLINE | ID: mdl-38715099

BACKGROUND: Prenatal nicotine exposure (PNE) has been documented to cause numerous deleterious effects on fetal development. However, the epigenetic changes promoted by nicotine exposure on germ cells are still not well understood. OBJECTIVES: In this study, we focused on elucidating the impact of prenatal nicotine exposure on regulatory epigenetic mechanisms important for germ cell development. METHODS: Sprague-Dawley rats were exposed to nicotine during pregnancy and male progeny was analyzed at 11 weeks of age. Testis morphology was analyzed using frozen testis sections and expression of germ cell markers was examined by RT-qPCR; histone modifications were assessed by Western Blot (WB). DNA methylation analysis was performed by methylation-specific PCR of bisulfite converted DNA. Genome-wide DNA methylation was analyzed using Methylated DNA immunoprecipitation (MeDIP)-seq. We also carried out transcriptomics analysis of pituitary glands by RNA-seq. RESULTS: We show that gestational exposure to nicotine reduces germ cell numbers, perturbs meiosis, affects the expression of germ line reprogramming responsive genes, and impacts the DNA methylation of nervous system genes in the testis. PNE also causes perturbation of gene expression in the pituitary gland of the brain. CONCLUSIONS: Our data demonstrate that PNE leads to perturbation of male spermatogenesis, and the observed effects are associated with changes of peripheral nervous system signaling pathways. Alterations in the expression of genes associated with diverse biological activities such as cell migration, cell adhesion and GABA signaling in the pituitary gland underscore the complexity of the effects of nicotine exposure during pregnancy.


DNA Methylation , Epigenesis, Genetic , Nicotine , Prenatal Exposure Delayed Effects , Rats, Sprague-Dawley , Testis , Animals , Male , Female , Pregnancy , Rats , Testis/drug effects , Testis/metabolism , Epigenesis, Genetic/drug effects , DNA Methylation/drug effects , Prenatal Exposure Delayed Effects/chemically induced , Prenatal Exposure Delayed Effects/metabolism , Signal Transduction/drug effects , Spermatogenesis/drug effects , Spermatogenesis/genetics , Peripheral Nervous System/drug effects , Peripheral Nervous System/metabolism
2.
Biomolecules ; 14(5)2024 Apr 30.
Article En | MEDLINE | ID: mdl-38785943

In the present study, we conducted a scoping review to provide an overview of the existing literature on the carbocyanine dye DiI, in human neuroanatomical tract tracing. The PubMed, Scopus, and Web of Science databases were systematically searched. We identified 61 studies published during the last three decades. While studies incorporated specimens across human life from the embryonic stage onwards, the majority of studies focused on adult human tissue. Studies that utilized peripheral nervous system (PNS) tissue were a minority, with the majority of studies focusing on the central nervous system (CNS). The most common topic of interest in previous tract tracing investigations was the connectivity of the visual pathway. DiI crystals were more commonly applied. Nevertheless, several studies utilized DiI in a paste or dissolved form. The maximum tracing distance and tracing speed achieved was, respectively, 70 mm and 1 mm/h. We identified studies that focused on optimizing tracing efficacy by varying parameters such as fixation, incubation temperature, dye re-application, or the application of electric fields. Additional studies aimed at broadening the scope of DiI use by assessing the utility of archival tissue and compatibility of tissue clearing in DiI applications. A combination of DiI tracing and immunohistochemistry in double-labeling studies have been shown to provide the means for assessing connectivity of phenotypically defined human CNS and PNS neuronal populations.


Neuroanatomical Tract-Tracing Techniques , Humans , Neuroanatomical Tract-Tracing Techniques/methods , Carbocyanines/chemistry , Central Nervous System , Peripheral Nervous System , Fluorescent Dyes/chemistry
3.
Curr Biol ; 34(10): 2175-2185.e4, 2024 05 20.
Article En | MEDLINE | ID: mdl-38718797

Relatively little is known about how peripheral nervous systems (PNSs) contribute to the patterning of behavior in which their role transcends the simple execution of central motor commands or mediation of reflexes. We sought to draw inferences to this end in the aeolid nudibranch Berghia stephanieae, which generates a rapid, dramatic defense behavior, "bristling." This behavior involves the coordinated movement of cerata, dozens of venomous appendages emerging from the animal's mantle. Our investigations revealed that bristling constitutes a stereotyped but non-reflexive two-stage behavior: an initial adduction of proximate cerata to sting the offending stimulus (stage 1) followed by a coordinated radial extension of remaining cerata to create a pincushion-like defensive screen around the animal (stage 2). In decerebrated specimens, stage 1 bristling was preserved, while stage 2 bristling was replaced by slower, uncoordinated ceratal movements. We conclude from these observations that, first, the animal's PNS and central nervous system (CNS) mediate stages 1 and 2 of bristling, respectively; second, the behavior propagates through the body utilizing both peripheral- and central-origin nerve networks that support different signaling kinetics; and third, the former network inhibits the latter in the body region being stimulated. These findings extend our understanding of the PNS' computational capacity and provide insight into a neuroethological scheme in which the CNS and PNS both independently and interactively pattern different aspects of non-reflexive behavior.


Central Nervous System , Peripheral Nervous System , Animals , Central Nervous System/physiology , Peripheral Nervous System/physiology , Behavior, Animal/physiology , Invertebrates/physiology
4.
Exp Dermatol ; 33(5): e15104, 2024 May.
Article En | MEDLINE | ID: mdl-38794817

Psoriasis is a chronic systemic inflammatory cutaneous disease. Where the immune system plays an important role in its pathogenesis, with key inflammatory intercellular signalling peptides and proteins including IL-17 and IL-23. The psychoneurological system also figures prominently in development of psoriasis. There is a high prevalence of comorbidity between psoriasis and mental health disorders such as depression, anxiety and mania. Patients with psoriasis often suffer from pathological pain in the lesions, and their neurological accidents could improve the lesions in innervated areas. The immune system and the psychoneurological system interact closely in the pathogenesis of psoriasis. Patients with psoriasis exhibit abnormal levels of neuropeptides both in circulating and localized lesion, acting as immunomodulators involved in the inflammatory response. Moreover, receptors for inflammatory factors are expressed in both peripheral and central nervous systems (CNSs), suggesting that nervous system can receive and be influenced by signals from immune system. Key inflammatory intercellular signalling peptides and proteins in psoriasis, such as IL-17 and IL-23, can be involved in sensory signalling and may affect synaptic plasticity and the blood-brain barrier of CNS through the circulation. This review provides an overview of the multiple effects on the peripheral and CNS under conditions of systemic inflammation in psoriasis, providing a framework and inspiration for in-depth studies of neuroimmunomodulation in psoriasis.


Central Nervous System , Interleukin-17 , Interleukin-23 , Psoriasis , Psoriasis/metabolism , Psoriasis/immunology , Humans , Central Nervous System/metabolism , Interleukin-23/metabolism , Interleukin-17/metabolism , Neuroimmunomodulation , Neuropeptides/metabolism , Inflammation/metabolism , Peripheral Nervous System/metabolism , Animals , Signal Transduction
5.
Orphanet J Rare Dis ; 19(1): 217, 2024 May 24.
Article En | MEDLINE | ID: mdl-38790028

BACKGROUND: To investigate the peripheral nervous system involvement in S sialidosis with typical features of myoclonus, seizure, and giant waves in somatosensory evoked potentials suggesting hyperexcitability in the central nervous system. METHODS: The clinical presentation of patients with genetically confirmed sialidosis was recorded. Neurophysiological studies, including nerve conduction studies (NCSs), F-wave studies, and needle electromyography (EMG), were performed on these patients. RESULTS: Six patients (M/F: 2:4) were recruited. In addition to the classical presentation, intermittent painful paresthesia was noted in four patients, and three of whom reported it as the earliest symptom. In the NCSs, one patient had reduced compound muscle action potential amplitudes in the right ulnar nerve, while another patient had prolonged distal motor latency in the bilateral tibial and peroneal nerves. Prolonged F-wave latency (83.3%), repeater F-waves (50%), and neurogenic polyphasic waves in EMG (in 2 out of 3 examined patients) were also noted. Interestingly, a very late response was noted in the F-wave study of all patients, probably indicating lesions involving the proximal peripheral nerve or spinal cord. CONCLUSION: In addition to the central nervous system, the peripheral nervous system is also involved in sialidosis, with corresponding clinical symptoms. Further study on these phenomena is indicated.


Electromyography , Mucolipidoses , Humans , Male , Female , Adult , Mucolipidoses/physiopathology , Neural Conduction/physiology , Young Adult , Peripheral Nerves/physiopathology , Peripheral Nerves/pathology , Adolescent , Peripheral Nervous System/physiopathology , Evoked Potentials, Somatosensory/physiology , Middle Aged , Child
7.
BMC Biol ; 22(1): 74, 2024 Apr 02.
Article En | MEDLINE | ID: mdl-38561802

BACKGROUND: The tunicates form a group of filter-feeding marine animals closely related to vertebrates. They share with them a number of features such as a notochord and a dorsal neural tube in the tadpole larvae of ascidians, one of the three groups that make tunicates. However, a number of typical chordate characters have been lost in different branches of tunicates, a diverse and fast-evolving phylum. Consequently, the tunic, a sort of exoskeleton made of extracellular material including cellulose secreted by the epidermis, is the unifying character defining the tunicate phylum. In the larva of ascidians, the tunic differentiates in the tail into a median fin (with dorsal and ventral extended blades) and a caudal fin. RESULTS: Here we have performed experiments in the ascidian Phallusia mammillata to address the molecular control of tunic 3D morphogenesis. We have demonstrated that the tail epidermis medio-lateral patterning essential for peripheral nervous system specification also controls tunic elongation into fins. More specifically, when tail epidermis midline identity was abolished by BMP signaling inhibition, or CRISPR/Cas9 inactivation of the transcription factor coding genes Msx or Klf1/2/4/17, median fin did not form. We postulated that this genetic program should regulate effectors of tunic secretion. We thus analyzed the expression and regulation in different ascidian species of two genes acquired by horizontal gene transfer (HGT) from bacteria, CesA coding for a cellulose synthase and Gh6 coding for a cellulase. We have uncovered an unexpected dynamic history of these genes in tunicates and high levels of variability in gene expression and regulation among ascidians. Although, in Phallusia, Gh6 has a regionalized expression in the epidermis compatible with an involvement in fin elongation, our functional studies indicate a minor function during caudal fin formation only. CONCLUSIONS: Our study constitutes an important step in the study of the integration of HGT-acquired genes into developmental networks and a cellulose-based morphogenesis of extracellular material in animals.


Urochordata , Animals , Urochordata/genetics , Morphogenesis/genetics , Epidermis , Peripheral Nervous System , Larva/genetics , Cellulose
8.
Exp Neurol ; 377: 114783, 2024 Jul.
Article En | MEDLINE | ID: mdl-38688418

The structural and functional features of lymphatic vessels in the peripheral nervous system (pLVs) is still unclear. Here, we clarify the existence of pLVs in rats, PROX1-EGFP transgenic mice and human, and exhibit a clear three-dimensional structure for helping understand its structural features. Moreover, two specific phenotypes of lymphatics endothelial cells (Rnd1Hi LECs and Ccl21Hi LECs) in peripheral nerves are well characterized by single-cell sequencing. Subsequently, the ability of trans-lymphatic delivery to peripheral nerves via pLVs has been dynamically demonstrated. After peripheral nerve injury (PNI), extensive lymphangiogenesis occurs in the lesion area and further enhances the efficiency of retrograde lymphatic-nerve transport. In PNI animal models, subcutaneously footpad-injected exosomes are efficiently delivered to sciatic nerve via pLVs which can promote nerve regeneration. The trans-lymphatic delivery to peripheral nerves via pLVs can subtly bypass BNB which provides an easy and alternative delivery route for PNI treatment.


Lymphatic Vessels , Mice, Transgenic , Nerve Regeneration , Peripheral Nerve Injuries , Animals , Nerve Regeneration/physiology , Lymphatic Vessels/physiology , Mice , Peripheral Nerve Injuries/pathology , Rats , Humans , Peripheral Nervous System , Rats, Sprague-Dawley , Male , Sciatic Nerve/physiology , Sciatic Nerve/injuries , Lymphangiogenesis/physiology , Endothelial Cells/physiology , Exosomes/metabolism
9.
Int J Mol Sci ; 25(7)2024 Mar 28.
Article En | MEDLINE | ID: mdl-38612597

Despite significant progress in modern medicine and pharmacology, damage to the nervous system with various etiologies still poses a challenge to doctors and scientists. Injuries lead to neuroimmunological changes in the central nervous system (CNS), which may result in both secondary damage and the development of tactile and thermal hypersensitivity. In our review, based on the analysis of many experimental and clinical studies, we indicate that the mechanisms occurring both at the level of the brain after direct damage and at the level of the spinal cord after peripheral nerve damage have a common immunological basis. This suggests that there are opportunities for similar pharmacological therapeutic interventions in the damage of various etiologies. Experimental data indicate that after CNS/PNS damage, the levels of 16 among the 28 CC-family chemokines, i.e., CCL1, CCL2, CCL3, CCL4, CCL5, CCL6, CCL7, CCL8, CCL9, CCL11, CCL12, CCL17, CCL19, CCL20, CCL21, and CCL22, increase in the brain and/or spinal cord and have strong proinflammatory and/or pronociceptive effects. According to the available literature data, further investigation is still needed for understanding the role of the remaining chemokines, especially six of them which were found in humans but not in mice/rats, i.e., CCL13, CCL14, CCL15, CCL16, CCL18, and CCL23. Over the past several years, the results of studies in which available pharmacological tools were used indicated that blocking individual receptors, e.g., CCR1 (J113863 and BX513), CCR2 (RS504393, CCX872, INCB3344, and AZ889), CCR3 (SB328437), CCR4 (C021 and AZD-2098), and CCR5 (maraviroc, AZD-5672, and TAK-220), has beneficial effects after damage to both the CNS and PNS. Recently, experimental data have proved that blockades exerted by double antagonists CCR1/3 (UCB 35625) and CCR2/5 (cenicriviroc) have very good anti-inflammatory and antinociceptive effects. In addition, both single (J113863, RS504393, SB328437, C021, and maraviroc) and dual (cenicriviroc) chemokine receptor antagonists enhanced the analgesic effect of opioid drugs. This review will display the evidence that a multidirectional strategy based on the modulation of neuronal-glial-immune interactions can significantly improve the health of patients after CNS and PNS damage by changing the activity of chemokines belonging to the CC family. Moreover, in the case of pain, the combined administration of such antagonists with opioid drugs could reduce therapeutic doses and minimize the risk of complications.


Analgesics, Opioid , Imidazoles , Naphthalenes , Nitro Compounds , Sulfoxides , Trauma, Nervous System , Humans , Animals , Mice , Rats , Maraviroc , Central Nervous System , Peripheral Nervous System
10.
Adv Drug Deliv Rev ; 208: 115275, 2024 May.
Article En | MEDLINE | ID: mdl-38442747

Ultrasound is a promising technology to address challenges in drug delivery, including limited drug penetration across physiological barriers and ineffective targeting. Here we provide an overview of the significant advances made in recent years in overcoming technical and pharmacological barriers using ultrasound-assisted drug delivery to the central and peripheral nervous system. We commence by exploring the fundamental principles of ultrasound physics and its interaction with tissue. The mechanisms of ultrasonic-enhanced drug delivery are examined, as well as the relevant tissue barriers. We highlight drug transport through such tissue barriers utilizing insonation alone, in combination with ultrasound contrast agents (e.g., microbubbles), and through innovative particulate drug delivery systems. Furthermore, we review advances in systems and devices for providing therapeutic ultrasound, as their practicality and accessibility are crucial for clinical application.


Drug Delivery Systems , Ultrasonic Therapy , Humans , Ultrasonography , Peripheral Nervous System , Microbubbles
12.
BMC Complement Med Ther ; 24(1): 117, 2024 Mar 07.
Article En | MEDLINE | ID: mdl-38454382

A meditative 'technique' is conceived as a continuum of different affective states involving mind and body jointly. Meditative practices can involve cognitive effort (e.g., focused attention and open-minded techniques), as well as automatic and implicit practices (e.g., transcendental techniques). The NGALSO tantric self-healing meditation technique is a brief, comprehensive meditation technique relying on mind and body connection. In this study, we aimed to investigate the state and the trait neurophysiological correlates of NGALSO meditation practice. First, 19 EEG channels and a 3-lead ECG signal were recorded from 10 expert meditators (more than 7 years of daily meditation) and 10 healthy inexpert participants (controls) who underwent the same meditative procedure. The neuropsychological profiles of experts and controls were compared. Results showed that expert meditators had significantly higher power spectra on alpha, theta and beta, and a higher sympathetic tone with lower parasympathetic tone after meditation. Conversely, the control group had significantly less power spectra on alpha, theta and beta, and a higher parasympathetic tone with lower sympathetic tone after meditation. A machine learning approach also allowed us to classify experts vs. controls correctly by using only EEG Theta bands before or after meditation. ECG results allowed us to show a significantly higher effort by expert meditators vs. controls, thus suggesting that a higher effort is required for this meditation, in line with the principle 'no pain, no gain' in body and mind.


Meditation , Humans , Peripheral Nervous System
13.
Clin Neurophysiol ; 160: 75-94, 2024 04.
Article En | MEDLINE | ID: mdl-38412746

The blink reflex (BR) is integrated at the brainstem; however, it is modulated by inputs from various structures such as the striatum, globus pallidus, substantia nigra, and nucleus raphe magnus but also from afferent input from the peripheral nervous system. Therefore, it provides information about the pathophysiology of numerous peripheral and central nervous system disorders. The BR is a valuable tool for studying the integrity of the trigemino-facial system, the relevant brainstem nuclei, and circuits. At the same time, some neurophysiological techniques applying the BR may indicate abnormalities involving structures rostral to the brainstem that modulate or control the BR circuits. This is a state-of-the-art review of the clinical application of BR modulation; physiology is reviewed in part 1. In this review, we aim to present the role of the BR and techniques related to its modulation in understanding pathophysiological mechanisms of motor control and pain disorders, in which these techniques are diagnostically helpful. Furthermore, some BR techniques may have a predictive value or serve as a basis for follow-up evaluation. BR testing may benefit in the diagnosis of hemifacial spasm, dystonia, functional movement disorders, migraine, orofacial pain, and psychiatric disorders. Although the abnormalities in the integrity of the BR pathway itself may provide information about trigeminal or facial nerve disorders, alterations in BR excitability are found in several disease conditions. BR excitability studies are suitable for understanding the common pathophysiological mechanisms behind various clinical entities, elucidating alterations in top-down inhibitory systems, and allowing for follow-up and quantitation of many neurological syndromes.


Dystonic Disorders , Hemifacial Spasm , Humans , Blinking , Peripheral Nervous System , Facial Pain , Reflex/physiology
14.
Am J Occup Ther ; 78(2)2024 Mar 01.
Article En | MEDLINE | ID: mdl-38305818

IMPORTANCE: Handedness and motor asymmetry are important features of occupational performance. With an increased understanding of the basic neural mechanisms surrounding handedness, clinicians will be better able to implement targeted, evidence-based neurorehabilitation interventions to promote functional independence. OBJECTIVE: To review the basic neural mechanisms behind handedness and their implications for central and peripheral nervous system injury. DATA SOURCES: Relevant published literature obtained via MEDLINE. FINDINGS: Handedness, along with performance asymmetries observed between the dominant and nondominant hands, may be due to hemispheric specializations for motor control. These specializations contribute to predictable motor control deficits that are dependent on which hemisphere or limb has been affected. Clinical practice recommendations for occupational therapists and other rehabilitation specialists are presented. CONCLUSIONS AND RELEVANCE: It is vital that occupational therapists and other rehabilitation specialists consider handedness and hemispheric lateralization during evaluation and treatment. With an increased understanding of the basic neural mechanisms surrounding handedness, clinicians will be better able to implement targeted, evidence-based neurorehabilitation interventions to promote functional independence. Plain-Language Summary: The goal of this narrative review is to increase clinicians' understanding of the basic neural mechanisms related to handedness (the tendency to select one hand over the other for specific tasks) and their implications for central and peripheral nervous system injury and rehabilitation. An enhanced understanding of these mechanisms may allow clinicians to better tailor neurorehabilitation interventions to address motor deficits and promote functional independence.


Functional Laterality , Hand , Humans , Functional Laterality/physiology , Hand/physiology , Peripheral Nervous System , Language
15.
Handb Clin Neurol ; 199: 179-200, 2024.
Article En | MEDLINE | ID: mdl-38307646

The International Neuromodulation Society defines therapeutic neuromodulation as the alteration of nerve activity through targeted delivery of a stimulus, such as electrical stimulation or chemical agents, to specific neurological sites in the body. Neuromodulation for the treatment of migraine is an evolving field offering further insight into the pathophysiology of migraine as well as advanced therapeutics. Central and peripheral neuronal targets have been explored in the efforts to reduce the frequency and severity of attacks. Invasive and noninvasive techniques have been developed, targeting either the central or peripheral nervous system. Noninvasive central neuromodulation techniques have the benefit of a low side effect profile in addition to higher level of evidence for use thanks to sham-controlled trials; however, these modalities are less clinically available for use. Noninvasive transcutaneous neuromodulation techniques that target the peripheral nervous system have provided devices that are available over the counter or by prescription. Several of these devices are effective for abortive and preventive treatment of migraine. Invasive techniques such as cranial nerve stimulation with implanted stimulator devices or spinal cord stimulation may be used for more aggressive management in patients refractory to other treatments. Overall, neuromodulation techniques can be particularly beneficial for medically complex or refractory patients, those that prefer nonmedication options, and those that have experienced adverse effects from medications.


Electric Stimulation Therapy , Migraine Disorders , Transcutaneous Electric Nerve Stimulation , Humans , Migraine Disorders/therapy , Transcutaneous Electric Nerve Stimulation/methods , Peripheral Nervous System , Transcranial Magnetic Stimulation/methods
16.
Mol Cells ; 47(2): 100030, 2024 Feb.
Article En | MEDLINE | ID: mdl-38364960

Both brown and white adipose tissues (BAT/WAT) are innervated by the peripheral nervous system, including efferent sympathetic nerves that communicate from the brain/central nervous system out to the tissue, and afferent sensory nerves that communicate from the tissue back to the brain and locally release neuropeptides to the tissue upon stimulation. This bidirectional neural communication is important for energy balance and metabolic control, as well as maintaining adipose tissue health through processes like browning (development of metabolically healthy brown adipocytes in WAT), thermogenesis, lipolysis, and adipogenesis. Decades of sensory nerve denervation studies have demonstrated the particular importance of adipose sensory nerves for brown adipose tissue and WAT functions, but far less is known about the tissue's sensory innervation compared to the better-studied sympathetic nerves and their neurotransmitter norepinephrine. In this review, we cover what is known and not yet known about sensory nerve activities in adipose, focusing on their effector neuropeptide actions in the tissue.


Adipose Tissue, Brown , Adipose Tissue, White , Humans , Adipose Tissue, White/innervation , Adipose Tissue, White/metabolism , Adipose Tissue, Brown/metabolism , Obesity/metabolism , Thermogenesis , Peripheral Nervous System/metabolism
17.
Acad Emerg Med ; 31(4): 386-397, 2024 04.
Article En | MEDLINE | ID: mdl-38419365

INTRODUCTION: Acute presentations and emergencies in neuromuscular disorders (NMDs) often challenge clinical acumen. The objective of this review is to refine the reader's approach to history taking, clinical localization and early diagnosis, as well as emergency management of neuromuscular emergencies. METHODS: An extensive literature search was performed to identify relevant studies. We prioritized meta-analysis, systematic reviews, and position statements where possible to inform any recommendations. SUMMARY: The spectrum of clinical presentations and etiologies ranges from neurotoxic envenomation or infection to autoimmune disease such as Guillain-Barré Syndrome (GBS) and myasthenia gravis (MG). Delayed diagnosis is not uncommon when presentations occur "de novo," respiratory failure is dominant or isolated, or in the case of atypical scenarios such as GBS variants, severe autonomic dysfunction, or rhabdomyolysis. Diseases of the central nervous system, systemic and musculoskeletal disorders can mimic presentations in neuromuscular disorders. CONCLUSIONS: Fortunately, early diagnosis and management can improve prognosis. This article provides a comprehensive review of acute presentations in neuromuscular disorders relevant for the emergency physician.


Guillain-Barre Syndrome , Myasthenia Gravis , Neuromuscular Diseases , Humans , Emergencies , Neuromuscular Diseases/diagnosis , Neuromuscular Diseases/therapy , Myasthenia Gravis/diagnosis , Myasthenia Gravis/therapy , Guillain-Barre Syndrome/diagnosis , Guillain-Barre Syndrome/therapy , Peripheral Nervous System , Emergency Service, Hospital
18.
PLoS One ; 19(2): e0296872, 2024.
Article En | MEDLINE | ID: mdl-38329975

Many soft-bodied animals have extensive peripheral nervous systems (PNS) with significant sensory roles. One such, the sea slug Pleurobranchaea californica, uses PNS computations in its chemotactile oral veil (OV) in prey tracking, averaging olfactory stimuli across the OV to target likely source direction, or "stimulus place". This suggests a peripheral subepithelial network (SeN) interconnecting sensory sites to compute the directional average. We pursued anatomy and connectivity of previously described ciliated putative sensory cells on OV papillae. Scanning electron microscopy (SEM) confirmed paddle-shaped cilia in clusters. Anti-tubulin and phalloidin staining showed connections to branching nervelets and muscle fibers for contraction and expansion of papillae. Ciliary cell processes could not be traced into nerves, consistent with sensory transmission to CNS via secondary afferents. Anti-tyrosine hydroxylase-stained ciliated cells in clusters and revealed an at least partially dopaminergic subepithelial network interconnecting clusters near and distant, connections consistent with PNS averaging of multiple stimulated loci. Other, unidentified, SeN neurotransmitters are likely. Confirming chemotactile functions, perfusible suction electrodes recorded ciliary spiking excited by both mechanical and appetitive chemical stimuli. Stimuli induced sensory nerve spiking like that encoding stimulus place. Sensory nerve spikes and cilia cluster spikes were not identifiable as generated by the same neurons. Ciliary clusters likely drive the sensory nerve spikes via SeN, mediating appetitive and stimulus place codes to CNS. These observations may facilitate future analyses of the PNS in odor discrimination and memory, and also suggest such SeNs as potential evolutionary precursors of CNS place-coding circuitry in the segmented, skeletonized protostomes and deuterostomes.


Pleurobranchaea , Animals , Peripheral Nervous System , Neurons , Aplysia , Predatory Behavior
19.
Acta Neuropathol Commun ; 12(1): 24, 2024 Feb 08.
Article En | MEDLINE | ID: mdl-38331815

Myelin sheath abnormality is the cause of various neurodegenerative diseases (NDDs). G-proteins and their coupled receptors (GPCRs) play the important roles in myelination. Gnao1, encoding the major Gα protein (Gαo) in mammalian nerve system, is required for normal motor function. Here, we show that Gnao1 restricted to Schwann cell (SCs) lineage, but not neurons, negatively regulate SC differentiation, myelination, as well as re-myelination in peripheral nervous system (PNS). Mice lacking Gnao1 expression in SCs exhibit faster re-myelination and motor function recovery after nerve injury. Conversely, mice with Gnao1 overexpression in SCs display the insufficient myelinating capacity and delayed re-myelination. In vitro, Gnao1 deletion in SCs promotes SC differentiation. We found that Gnao1 knockdown in SCs resulting in the elevation of cAMP content and the activation of PI3K/AKT pathway, both associated with SC differentiation. The analysis of RNA sequencing data further evidenced that Gnao1 deletion cause the increased expression of myelin-related molecules and activation of regulatory pathways. Taken together, our data indicate that Gnao1 negatively regulated SC differentiation by reducing cAMP level and inhibiting PI3K-AKT cascade activation, identifying a novel drug target for the treatment of demyelinating diseases.


Phosphatidylinositol 3-Kinases , Proto-Oncogene Proteins c-akt , Animals , Mice , GTP-Binding Proteins , Mammals/metabolism , Myelin Sheath/metabolism , Peripheral Nervous System/metabolism , Proto-Oncogene Proteins c-akt/metabolism , Schwann Cells
20.
Cell Res ; 34(2): 124-139, 2024 02.
Article En | MEDLINE | ID: mdl-38168640

Achieving uniform optical resolution for a large tissue sample is a major challenge for deep imaging. For conventional tissue clearing methods, loss of resolution and quality in deep regions is inevitable due to limited transparency. Here we describe the Transparent Embedding Solvent System (TESOS) method, which combines tissue clearing, transparent embedding, sectioning and block-face imaging. We used TESOS to acquire volumetric images of uniform resolution for an adult mouse whole-body sample. The TESOS method is highly versatile and can be combined with different microscopy systems to achieve uniformly high resolution. With a light sheet microscope, we imaged the whole body of an adult mouse, including skin, at a uniform 0.8 × 0.8 × 3.5 µm3 voxel resolution within 120 h. With a confocal microscope and a 40×/1.3 numerical aperture objective, we achieved a uniform sub-micron resolution in the whole sample to reveal a complete projection of individual nerve axons within the central or peripheral nervous system. Furthermore, TESOS allowed the first mesoscale connectome mapping of individual sensory neuron axons spanning 5 cm from adult mouse digits to the spinal cord at a uniform sub-micron resolution.


Axons , Imaging, Three-Dimensional , Mice , Animals , Solvents , Imaging, Three-Dimensional/methods , Spinal Cord , Peripheral Nervous System
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