Non-myelinated Fibres Research Articles

Approach for Electrophysiological Studies of Spinal Lamina X Neurons.

Despite playing diverse physiological roles, the area surrounding the central canal, lamina X, remains one of the least studied spinal cord regions. Technical challenges and limitations of the commonly used experimental approaches are the main difficulties that hamper lamina X research. In the current protocol, we describe a reliable method for functional investigation of lamina X neurons that requires neither time-consuming slicing nor sophisticated in vivo experiments. Our approach relies on ex vivo hemisected spinal cord preparation that preserves the rostrocaudal and mediolateral spinal architecture as well as the dorsal roots, and infrared LED oblique illumination for visually guided patch clamp in thick blocks of tissue. When coupled with electric stimulation of the spared dorsal roots, electrophysiological recordings provide information on primary afferent inputs to lamina X neurons from myelinated and non-myelinated fibers and allow estimating primary afferent-driven presynaptic inhibition. Overall, we describe a simple, time-efficient, inexpensive, and versatile approach for lamina X research. Key features • Quick and easy preparation procedure that grants access to lamina X neurons without spinal cord slicing • Preserved rostrocaudal and mediolateral connectivity and preserved primary afferent supply • Ability to perform electrophysiological recordings in combination with dorsal root stimulations allowing to study afferent inputs and presynaptic inhibition of lamina X neurons.

The Duration and Intensity of High Frequency Alternating Current Influences the Degree and Recovery of Nerve Conduction Block.

The purpose of this paper is to investigate the persistence of nerve blockade beyond the duration of applying high frequency alternating current (HFAC) to thinly myelinated and non-myelinated fibers, also termed a "carry-over effect". In this study, we used electrically-evoked compound action potentials from isolated rat vagus nerves to assess the influence of 5 kHz HFAC amplitude and duration on the degree of the carry-over effect. Current amplitudes from 1-10 mA and 5 kHz durations from 10-120 seconds were tested. By testing 20 different combinations of 5 kHz amplitude and duration, we found a significant interaction between 5 kHz amplitude and duration on influencing the carry-over effect. The degree of carry-over effect was dependent on 5 kHz amplitude, as well as duration. Utilizing the carry-over effect may be useful in designing energy efficient nerve blocking algorithms for the treatment of diseases influenced by nerve activity.

Nerve Preparation and Recordings for Pharmacological Tests of Sensory and Nociceptive Fiber Conduction Ex Vivo.

Measuring signal propagation through nerves is a classical electrophysiological technique established decades ago to evaluate sensory and motor functions in the nervous system. The whole-nerve preparation provides a valuable model to investigate nerve function ex vivo; however, it requires specific knowledge to ensure successful and stable measurements. Although the methodology for sciatic nerve recordings has long existed, a method for reliable and long-lasting recordings from myelinated and non-myelinated (nociceptive) fibers still needs to be adapted for pharmacological testing. This protocol takes benefits from epineurium sheath removal for pharmacological tests and provides a detailed description of how to make accurate nerve preparations, from the dissection and handling of nerves to epineurium cleaning, fabrication of adaptable suction electrodes for appropriate fiber stimulation and recordings, setting of electrophysiological protocols for compound action potential (CAP) recordings to distinguish between myelinated and non-myelinated (nociceptive) fibers, and finally to the analysis of the datasets of CAP components. We also demonstrate the feasibility of CAP recordings from individual branches in epineurium-free nerve preparations and provide clues to help retain nerve viability and maintain stable recordings over time. Although a sciatic nerve preparation was used here, the methodology can be applied to other nerve-type preparations. Key features • Detailed and simplified protocol for peripheral nerve preparation for recording sensory inputs ex vivo. • Recordings from myelinated and non-myelinated (nociceptive) fibers can be performed hours after nerve preparation. • The protocol involves the epineurium removal to facilitate drug permeability into nerve tissue for pharmacological tests. • The protocol allows physiological and pathological studies (pain/chronic pain conditions).

Реактивные изменения соединительнотканных структур в периферических нервах овец при патологии печени

Experimental studies were carried out on sheep using a tetramethane model of hepatosis. Ultrastructural data made it possible to characterize morphofunctional changes in peripheral nerves in sheep, in particular, in myelinated and non-myelinated fibers, neurolemmocytes, and connective tissue structures. The pathological process in the peripheral nervous system initiates a combined pathology of the abdominal organs. This is due to the commonality of their innervation with the dorsal and ventral vagus, celiac, phrenic nerves, and branches of the solar plexus. A decrease in the trophic function of the nerves leads to morphological changes in the pancreas, adrenal glands, kidneys, stomach, and small intestine, which were recorded at the ultrastructural level. As a result, hypoxia, energy and plastic insecurity occur, which leads to destructive processes that involve neurolemmocytes, nerve fibers, neurocytes, connective tissue cells and collagen fibers. Structural and functional changes in sheep, with experimental hepatosis, contribute to quantitative and qualitative changes in the nucleoplasm, cytoplasm, swelling and detachment of the karyolemma. Destruction of organelles depends on the intimate processes of cytolysis. At the same time, the connective tissue in the peripheral nerves suffers significantly, and its functional state largely determines the reactivity of the body. It accumulates various substances. An ultrastructural study of clinically healthy animals shows that in the peripheral nerves, in addition to the nerve components, bundles of collagen fibers form a large volume, where they form a dense tie, passing in different directions. Each of them consists of thinner fibrils, which in turn are bundles of subfibrils. Among the fibers are fibroblasts, which have a different degree of differentiation. Thus, mature fibroblasts have a welldeveloped granular endoplasmic reticulum and numerous ribosomes, with an actively functioning Golgi apparatus, mitochondria, and few microfilaments. In pathology, the qualitative composition of fibroblasts changes, lysis of collagen fibers occurs, and communication with neurolemmocytes is lost. At the same time, fibroblasts strengthen contacts with each other. Such contacts between two, three or more fibroblasts are often seen. Others are located next to vascular endothelial cells and pericytes. Apparently, in pathology, fibroblasts require an informative field for the overall coordination of adaptive processes. On the other hand, it is known that fibroblasts begin to produce IL-1, which affects many processes in the body, in particular, it changes the synthetic functions. This is probably why the connective tissue framework in peripheral nerves changes, and their decay, in turn, stimulates the production of IL-1 by fibroblasts. The latter not only destroys connective tissue elements, but also activates the secretion of collagenase, the processes of proliferation and differentiation of fibroblasts. Fibroblasts activated by IL1 produce PGE2.

Гистоморфометрические характеристики передней большеберцовой мышцы и малоберцового нерва при экспериментальном замещении пострезекционного дефекта голени аппаратом Илизарова в комбинации с методом Masquelet

Objective Explore structural changes in the tibialis anterior muscle (TAM) and the peroneal nerve (PN) in repair of postresection tibial defect using the Ilizarov external fixation and a cement spacer. Material and methods A defect-nonunion was simulated in the proximal tibia of 10 mongrels using the Ilizarov external fixation followed by use of a cement spacer to fill the 2.5 cm defect-diastasis. The spacer was removed after 30 days and tibia distraction commenced with the rate of 1 mm performed 4 times/day following transverse osteotomy in the distal tibia to achieve docking of bone fragments. Animals were sacrificed after 60-day fixation (F60) and 30 days after frame removal (FR30). Histomorphometric parameters of the TAM and PN samples were examined. Results TAM appeared to be denervated with death or decreased size of myons and angular contours noted at F60 and FR30. Degenerated and intact muscle fibers (MF) were shown to increase by 32.5 % and by 1 %, respectively, at FR30. The peak of histogram distributing MF by diameters at F60 indicated to ischemic muscles, and a 2-fold decrease in muscle diameter and the histogram skewed to the left by 4 classes showed increase in muscle atrophy at FR30. Reactive destructive changes were noted in at least 5.4 % of myelinated nerve fibres of the PN at F60 and FR30. A 1.6-to-1.7 times decrease in larger and a 1.6-to-1.8 times increase in smaller fibers, the presence of regenerative clusters indicated to previous destruction of a large number of motor and sensory nerves. Changes in the population structure, destruction of myelinated fibers and loss of non-myelinated fibers were associated with obliteration of epineurial vessels and loss of endoneurial capillaries at F60. Conclusion Reactive destructive changes in the TAM and PN revealed in bone defects repaired with the Ilizarov external fixation and the Masquelet technique should be considered in planning of postoperative pharmacologic thearapy and rehabilitation.

Comparison of nerve fibers in the deciduous first and second molar teeth: an in vitro study.

Sensory nerves of the tooth pulp have been evolved in both deciduous and permanent teeth for conducting possible damages to the teeth. Although it has been reported that the deciduous tooth's pulp is histologically similar to permanent teeth, the difference in the density of nerves between the first and second deciduous molars has been reported in no studies. The aim of the study was to investigate the histological assay of pulpal nerves and assess the relationship between diameter and density of nerve fibres in the first and second deciduous molar teeth. In this in vitro study, 15 deciduous first and 16 deciduous second extracted from molar teeth belonging to children aged from 5 to 8years were studied. After fixation, the decalcified teeth were sectioned and then stained with silver solution and calcitonin gene-related peptide (CGRP) antibody. The mean diameter of myelinated fibres, un-myelinated fibres, and density of peripheral network fibres of dental pulp were examined. The results showed that the mean diameter of myelinated and non-myelinated fibres and density of nerve fibres were significantly more in the second molars (4.269, 2.328µm, 2.6 fibres per unit area) compared to the first molar teeth (3.793, 2.093µm, 1.8 fibres per unit area) (P < 0.032, 0.019, 0.003, respectively). An important finding in this study, which is reported for the first time, is the presence of fatty cells (adipocytes) in pulp tissue of some of the first deciduous molars as well as the second molars. Based on the results of the current study, differences between nerve fibres of first and second molar teeth are significant. It could be concluded that the less sensitivity to pain of the first deciduous molars compared with the second deciduous molars, is due to the lower nerve density of this tooth.

Determining Direction of Axonal Flow in the Equine Ramus Communicans by Ultrastructural Examination of the Plantar Nerves 2 Months after Transecting the Ramus.

The ramus communicans, neural connection between medial and lateral plantar nerves of the horse, was transected to determine the degree to which medial and lateral plantar nerves contribute to the plantar ramus. After 2 months, sections of plantar nerves immediately proximal and distal to the communicating branch were collected and processed for electron microscopy. All examined nerves had undergone Wallerian degeneration and contained regenerating and mature fibers. Layers of the myelin sheath were separated by spaces and vacuoles, indicating demyelination of medial and lateral plantar nerves. Shrunken axons varied in diameter and were surrounded by an irregular axolemma. Shrunken axoplasm of both myelinated and non-myelinated fibers contained ruptured mitochondria and cristae, disintegrating cytoskeleton, and vacuoles of various sizes. The cytoplasm of neurolemmocytes contained various-sized vesicles, ruptured mitochondria within a fragile basal lamina and myelin whorls of multilayered structures indicative of Wallerian degeneration. These ultrastructural changes, found proximal and distal to the ramus in medial and lateral plantar nerves, suggest that axonal flow is bi-directional through the ramus communicans of the pelvic limbs of horses, a previously unreported finding. As well, maturity of nerves proximal and distal to the ramus indicates that all nerve fibers do not pass through the ramus.

Sutureless nerve repair with ECM bioscaffolds and laser-activated chitosan adhesive.

The outcome of peripheral nerve repair following transection is influenced by a number of factors but almost all approaches require anastomosis of the nerve using technically demanding microsurgical procedures. However, the use of sutures presents a number of unavoidable challenges including additional nerve trauma, stimulation of an inflammatory response, and endoneural fibrosis. The objective of the present study was to determine the efficacy of a sutureless approach to nerve repair. A rat sciatic nerve transection model was used with a laser-activated, chitosan-based adhesive (SurgiLux), combined with different forms of extracellular matrix (ECM), known to promote Schwann cell proliferation and nerve growth both in peripheral nerve applications. Following a 5 mm transection of the sciatic nerve, nerve guide wraps were prepared using: (1) laser-activated adhesive (SurgiLux) alone, (2) SurgiLux incorporating ECM (SurgiLux ECM), (3) ECM secured using SurgiLux, and (4) ECM secured using 8-0 Prolene sutures. A no treatment groups was used as a negative control. Evaluation of tissue remodeling was conducted with histolomorphometric assessment of neuroma, integrity of repair, nerve immunolabeling, ratio of myelinated to non-myelinated fibers, and amount of connective tissue. Quantitative and semi-quantitative analysis of the repaired nerve transections at 6 and 12 weeks showed that that SurgiLux incorporating powdered ECM (SurgiLux ECM), SurgiLux alone and ECM alone all improved the healing response compared to no-treatment controls, with less fibrotic tissue and more nerve staining. Histologic scoring showed that the SurgiLux ECM group showed the greatest increase in histologic score between the two time points tested. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 1698-1711, 2018.

The Variant p.(Arg183Trp) in SPTLC2 Causes Late-Onset Hereditary Sensory Neuropathy

Hereditary sensory and autonomic neuropathy 1 (HSAN1) is an autosomal dominant disorder that can be caused by variants in SPTLC1 or SPTLC2, encoding subunits of serine palmitoyl-CoA transferase. Disease variants alter the enzyme's substrate specificity and lead to accumulation of neurotoxic 1-deoxysphingolipids. We describe two families with autosomal dominant HSAN1C caused by a new variant in SPTLC2, c.547C>T, p.(Arg183Trp). The variant changed a conserved amino acid and was not found in public variant databases. All patients had a relatively mild progressive distal sensory impairment, with onset after age 50. Small fibers were affected early, leading to abnormalities on quantitative sensory testing. Sural biopsy revealed a severe chronic axonal neuropathy with subtotal loss of myelinated axons, relatively preserved number of non-myelinated fibers and no signs for regeneration. Skin biopsy with PGP9.5 labeling showed lack of intraepidermal nerve endings early in the disease. Motor manifestations developed later in the disease course, but there was no evidence of autonomic involvement. Patients had elevated serum 1-deoxysphingolipids, and the variant protein produced elevated amounts of 1-deoxysphingolipids in vitro, which proved the pathogenicity of the variant. Our results expand the genetic spectrum of HSAN1C and provide further detail about the clinical characteristics. Sequencing of SPTLC2 should be considered in all patients presenting with mild late-onset sensory-predominant small or large fiber neuropathy.

Differential effects of Diabetes Mellitus on nerve fibers by type of Diabetes

Type 1 (T1D) and Type 2 diabetes mellitus (T2D) are often assumed to have similar effects on nerve fibers with a common etiology of hyperglycemia. Mounting evidence suggests that T2D preferentially affects non-myelinated C-fibers compared to myelinated fibers. To evaluate whether differential loss of myelinated and unmyelinated fibers occurs in T1D and T2D, we studied 9 patients with T1D, 11 patients with T2D and 10 age-matched control patients with nerve conduction studies, autonomic function tests, skin biopsy of distal and proximal leg (hairy skin) and glabrous skin biopsy of the index finger. T1D and T2D patients had similar HgA1c, neuropathy exam and symptom scores. T1D patients had longer length of diabetes and lower BMI compared to T2D patients. T1D patients had significant loss of myelinated and non-myelinated fibers with lower myelinated fiber densities, intra-epidermal nerve fiber density (IENFD) and composite autonomic system score (CASS). T2D patients had no significant loss of myelinated fibers (20.3 vs. 21.7 myelinated fibers /mm for healthy controls), but had significant decrease in non-myelinated fibers as evidenced by decreased IENFD and abnormal CASS. T1D and T2D patients had similar intraepidermal nerve fiber density at the distal leg, and similar sweat volumes using quantitative sudomotor axon reflex testing. T1D patients had a trend towards worse cardiac autonomic function with CASS score mean of 3 vs 2 for T2D patients. These results suggest that focus on distal, non-myelinated fiber function and pathology may be more sensitive for T2D patients than traditional myelinated fiber-based measures of diabetic neuropathy.

A model of injury potential for myelinated nerve fiber.

Excellent models have been described in literatures which related membrane potential to extracellular electric or magnetic stimulation and which described the formation and propagation of action potentials along the axon, for both myelinated and nonmyelinated fibers. There is not, however, an adequate model for nerve injury which allows to compute the distribution of injury potential, a direct current potential difference between intact and injured nerve, because its importance has been ignored in the shadow of the well-known action potential. This paper focus on the injury potential and presents a model of the electrical properties of myelinated nerve which describes the time course of events following injury. The time-varying current and potential at all nodes can be computed from the model, and the factors relate to the amplitude of injury potential can be determined. It is shown that the amplitude of injury potential decreased gradually with injury time, and the recession curve was exponential. Results also showed that the initial amplitude of injury potential is positively related to the grade of injury and fiber diameter. This model explained the mechanism of formation of injury potential and can provide instruction for applied electric field to prevent the formation injury potential.

An uncommon pattern of polyneuropathy induced by lifetime exposures to drift containing organophosphate pesticides

The natural history of chronic peripheral polyneuropathy following lifetime low-level organophosphate (OP) exposure was investigated. A pilot study (1984–1987) conducted in rural communities in Israel detected subtle reversible in-season changes in nerve conduction patterns of 17 field workers out of 214 residents exposed to seasonal drift containing OP's. We examined 60 individuals (males: 50/60; 83.3%) from the original cohort still residing (more than 40 years) in the same communities. Exposure assessment was based on reports by Israeli institutions and the Bureau of Statistics. Information on personal status, work experience, exposures and symptoms was collected by questionnaires. The nervous system was systematically studied, evaluating cortical upper motor neurons, corticospinal tracts, lower motor neurons and peripheral nerves. Electrophysiological studies included conduction velocities, amplitudes and distal latencies of sensory and motor median, ulnar, tibial and sural nerves; F-waves for proximal nerve functions; thermal and pain thresholds for small thinly-myelinated and non-myelinated fibers; transcranial magnetic stimulation for large fibers.Clinical and electrophysiological features of Carpal Tunnel Syndrome were found in 18% of the subjects, atypically in males only. Fingertips’ tingling correlated with both axonal and myelin-dependent parameters (lower wave amplitudes and prolonged latency periods, respectively) in the sensory median nerves bilaterally. OP exposure significantly correlated to prolonged distal latency in the right median sensory nerve (r=0.29; p=0.052; n=45) and lower wave amplitude in the right sural nerve (p=0.031). These findings attest to subtle, predominantly sensory peripheral polyneuropathy following lifetime low-level exposures to drifts containing OP.

Functional correlates of central white matter maturation in perinatal period in rabbits

Anisotropy indices derived from diffusion tensor imaging (DTI) are being increasingly used as biomarkers of central WM structural maturation, myelination and even functional development. Our hypothesis was that the rate of functional changes in central WM tracts directly reflects rate of changes in structural development as determined by DTI indices.We examined structural and functional development of four major central WM tracts with different maturational trajectories, including internal capsule (IC), corpus callosum (CC), fimbria hippocampi (FH) and anterior commissure (AC). Rabbits were chosen due to perinatal brain development being similar to humans, and four time points were studied: P1, P11, P18 and adults. Imaging parameters of structural maturation included fractional anisotropy (FA), mean and directional diffusivities derived from DTI, and T2 relaxation time. Axonal composition and degree of myelination were confirmed on electron microscopy. To assess functional maturation, conduction velocity was measured in myelinated and non-myelinated fibers by electrophysiological recordings of compound action potential in perfused brain slices.Diffusion indices and T2 relaxation time in rabbits followed a sigmoid curve during development similar to that for humans, with active changes even at premyelination stage. The shape of the developmental curve was different between the fiber tracts, with later onset but steeper rapid phase of development in IC and FH than in CC. The structural development was not directly related to myelination or to functional development. Functional properties in projection (IC) and limbic tracts (FH) matured earlier than in associative and commissural tracts (CC and AC).The rapid phase of changes in diffusion anisotropy and T2 relaxation time coincided with the development of functional responses and myelination in IC and FH between the second and third weeks of postnatal development in rabbits. In these two tracts, MRI indices could serve as surrogate markers of the early stage of myelination. However, the discordance between developmental change of diffusion indices, myelination and functional properties in CC and AC cautions against equating DTI index changes as biomarkers for myelination in all tracts.

Assessing white matter microstructure of the newborn with multi-shell diffusion MRI and biophysical compartment models

Brain white matter connections have become a focus of major interest with important maturational processes occurring in newborns. To study the complex microstructural developmental changes in-vivo, it is imperative that non-invasive neuroimaging approaches are developed for this age-group.Multi-b-value diffusion weighted imaging data were acquired in 13 newborns, and the biophysical compartment diffusion models CHARMED-light and NODDI, providing new microstructural parameters such as intra-neurite volume fraction (νin) and neurite orientation dispersion index (ODI), were developed for newborn data. Comparative analysis was performed and twenty ROIs in the white matter were investigated. Diffusion tensor imaging and both biophysical compartment models highlighted the compact and oriented structure of the corpus-callosum with the highest FA and νin values and the smallest ODI values. We could clearly differentiate, using the FA, νin and ODI, the posterior and anterior internal capsule representing similar cellular structure but with different maturation (i.e. partially myelinated and absence of myelin, respectively). Late maturing regions (external capsule and periventricular crossroads of pathways) had lower νin values, but displayed significant differences in ODI. The compartmented models CHARMED-light and NODDI bring new indices corroborating the cellular architectures, with the lowest νin, reflecting the late maturation of areas with thin non-myelinated fibers, and with highest ODI indicating the presence of fiber crossings and fanning.The application of biophysical compartment diffusion models adds new insights to the brain white matter development in vivo.

Retinal Nerve Fiber Layer Thickness, Brain Atrophy, and Disability in Multiple Sclerosis Patients

To study the relationship between retinal nerve fiber layer (RNFL) thickness and brain atrophy using magnetic resonance imaging (MRI) with bicaudate ratio (BCR) in patients with multiple sclerosis (MS) with different levels of disease severity. We also assessed whether RNFL thickness correlated with Expanded Disability Status Scale (EDSS) score. The participants consisted of 88 patients with MS and 59 age- and sex-matched healthy control subjects. Eleven patients had clinically isolated syndrome (CIS), 68 patients had relapsing-remitting MS (RR-MS), and 9 patients had secondary progressive MS. Patients and controls were evaluated using optical coherence tomography (OCT, Cirrus) and scanning laser polarimetry with variable corneal compensation (GDx VCC). Patients underwent the same brain MRI scanning protocol. Disability was evaluated according to the EDSS. The BCR was calculated by dividing the minimum intercaudate distance by brain width along the same level. The BCR was higher in patients with MS (0.12 ± 0.03) than in controls (0.08 ± 0.009) (P < 0.001). OCT average RNFL thickness in patients with MS was significantly lower (84.51 ± 14.27 μm) than in control subjects (98.44 ± 6.83 μm). BCR was correlated with OCT average RNFL thickness (r = -0.48, P = 0.002) in patients with MS without optic neuritis. Significant correlations were found between average RNFL thickness and EDSS (r = -0.43, P = 0.003). Additionally, there were correlations between BCR with GDx parameters in patients with MS without optic neuritis. This study shows that RNFL thickness correlates with BCR and with MS subtypes. Additionally, our study indicates that OCT is better suited for MS assessment than GDx. We conclude that the damage of retinal axons appears related to brain damage in patients with MS.

Cyclic Changes of Nerve Fibers in Human Endometrium

Objective: The presence of nerve fibers in human endometrium remains unsettled but recent immunocytochemical studies have shown that there was increased innervation in the endometrium from women with endometriosis and some nerve fibers in the normally cycling human endometrium. In the current study, we used uterine tissue cryosections from normal cycling women, which previously provided better immunocytochemical staining for lymphatic vessels than in paraffin sections. Materials and Methods: A total of 16 cases from normally cycling women were included representing menstrual, early proliferative, early to late secretary phase. Neurofilament and CD 56 were used as immunocytochemical markers for nerve fibers with cryosections. Results: There were consistent presence of nerve fibers in myometrium and basalis. Few small nerve fibers were identified in early proliferative endometrium and more nerve fibers were present in lower-half functionalis from mid-secretary phase. Late-secretary functionalis showed less nerve fibers in the upper-half than the lower-half functionalis, implying growing nerve fibers from lower functionalis to upper functionalis in late-secretary phase. Conclusion: Nerve fibers appeared to cyclically grow from basalis to lower functionalis and then from lower functionalis to upper functionalis concomitantly with blood vessels in normally cycling human endometrium. These cycling endometrial nerve fibers consisted mostly of nonmyelinated small nerve fibers, which may transmit pelvic pain in the normally cycling women.

Early-onset CMT1B due to the MPZ mutation c.320A&gt;T associated with collateral inclusion body myopathy and Deafness

Aims: To present the case of a patient with early-onset demyelinating neuropathy due to a MPZ-mutation, associated with deafness and inclusion-body-myopathy. Methods: Nerve conduction studies, electromyography, muscle biopsy, genetic testing. Results and Discussion: In a 46yo male with slowly progressive weakness and wasting since childhood initially of the lower and later also of the distal upper-limbs, ptosis, recurrent hyper-CK-emia, and progressive hearing impairment, nerve conduction studies revealed mixed demyelinating and axonal polyneuropathy and electromyography revealed neurogenic motor unit architecture. Nerve biopsy disclosed diffuse loss of myelinated fibers, reduced diameter of non-myelinated fibers, and fibers with hypomyelination and variable internodal myelination. Muscle biopsy revealed classical features of inclusion-body-myopathy. Upon genetic diagnostic work-up the MPZ-mutation c.320A>T, p.Glu107Val was detected. Since his son presented with a similar phenotype, inclusion-body-myopathy was interpreted as secondary to the neuropathy. Conclusions: CMT1B may show secondary axonal loss and mild clinical manifestations Research Article British Journal of Medicine & Medical Research, 3(4): 832-840, 2013 833 despite early onset. CMT1B may be associated with severe hearing impairment and collateral inclusion-body-myopathy.

Modelling of an inflammatory and destructive process in peripheral nerves

The article contains data of a morphological analysis by results of transplantation of an autologous vertebral pulp of white rats to the tibial branch of the sciatic nerve. It is shown that on the 15 th day after the reproduction of this model the nervous trunk and perineural tissues of animals developed signs of a chronic inflammatory-destructive process. Destruction, vacuolization and fragmentation of the myelin sheath, destruction foci in nonmyelinated nerve fibres, nuclear heterochromatization and a low density of membrane organoids in the cytoplasm of Schwann’s cells were revealed on the ultrastructural level.

Role of Cardiac Reflexes in the Control of Heart Rate

Role of Cardiac Reflexes in the Control of Heart Rate

Breath‐taking complexity of vagal C‐fibre nociceptors: implications for inflammatory pulmonary disease, dyspnoea and cough

Breath‐taking complexity of vagal C‐fibre nociceptors: implications for inflammatory pulmonary disease, dyspnoea and cough