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Sample records for sensory nerve desensitization

  1. Sensory Desensitization Training for Successful Net Application and EEG/ERP Acquisition in Difficult to Test Children

    ERIC Educational Resources Information Center

    Roesler, Cynthia P.; Flax, Judy; MacRoy-Higgins, Michelle; Fermano, Zena; Morgan-Byrne, Julie; Benasich, April A.

    2013-01-01

    This study examined the effectiveness of sensory desensitization training for 12 nonverbal children with autism to facilitate participation in an electrophysiological study assessing linguistic processing. Sensory desensitization was achieved for 10 of the 12 children and thus allowed collection of usable data in a passive linguistic paradigm.…

  2. Paclitaxel alters sensory nerve biomechanical properties.

    PubMed

    Bober, Brian G; Shah, Sameer B

    2015-10-15

    Paclitaxel is an effective chemotherapeutic that, despite its common use, frequently causes debilitating peripheral sensory neuropathy. Paclitaxel binds to and stabilizes microtubules, and through unknown mechanisms, causes abnormal microtubule aggregation. Given that microtubules contribute to the mechanical properties of cells, we tested the hypothesis that paclitaxel treatment would alter the stiffness of sensory nerves. Rat sural nerves were excised and soaked in Ringer's solution with or without paclitaxel. Nerves were secured between a force transducer and actuator, and linearly strained. Stress-strain curves were generated, from which elastic moduli were calculated. Paclitaxel treated nerves exhibited significantly higher moduli in both linear and transition regions of the curve. A composite-tissue model was then generated to estimate the stiffness increase in the cellular fraction of the nerve following paclitaxel treatment. This model was supported experimentally by data on mechanical properties of sural nerves stripped of their epineurium, and area fractions of the cellular and connective tissue components of the rat sural nerve, calculated from immunohistochemical images. Model results revealed that the cellular components of the nerve must stiffen 12x to 115x, depending on the initial axonal modulus assumed, in order to achieve the observed tissue level mechanical changes. Consistent with such an increase, electron microscopy showed increased microtubule aggregation and cytoskeletal packing, suggestive of a more cross-linked cytoskeleton. Overall, our data suggests that paclitaxel treatment induces increased microtubule bundling in axons, which leads to alterations in tissue-level mechanical properties. PMID:26321364

  3. Contribution of the distal nerve sheath to nerve and muscle preservation following denervation and sensory protection.

    PubMed

    Veltri, Karen; Kwiecien, Jacek M; Minet, Wyatt; Fahnestock, Margaret; Bain, James R

    2005-01-01

    The goal of this study was to determine the contribution of the distal nerve sheath to sensory protection. Following tibial nerve transection, rats were assigned to one of the following groups: (1) saphenous-to-tibial nerve neurorrhaphy; (2) saphenous-to-gastrocnemius neurotization; (3) unprotected controls (tibial nerve transection); or (4) immediate common peroneal-to-tibial nerve neurorrhaphy. After a 6-month denervation period and motor reinnervation, ultrastructural, histologic, and morphometric analyses were performed on the distal tibial nerve and gastrocnemius muscle cross-sections. Sensory axons neurotized to muscle maintain existing muscle integrity, as demonstrated by less fibrosis, collagenization, and fat deposition, more than unprotected muscle, and preserve the distribution pattern of fast twitch fibers. However, neurorrhaphy of the sensory nerve to the distal tibial nerve (involving the distal nerve sheath) improves existing endoneurial sheath structure, demonstrated by reduced collagen, and enhances regeneration, shown by improved axon-to-Schwann cell coupling and increased axon area. The authors conclude that sensory protection of muscle does not require the distal nerve sheath, but that preservation of the distal sheath may contribute to enhanced nerve regeneration. PMID:15672322

  4. Neonatal sensory nerve injury-induced synaptic plasticity in the trigeminal principal sensory nucleus.

    PubMed

    Lo, Fu-Sun; Erzurumlu, Reha S

    2016-01-01

    Sensory deprivation studies in neonatal mammals, such as monocular eye closure, whisker trimming, and chemical blockade of the olfactory epithelium have revealed the importance of sensory inputs in brain wiring during distinct critical periods. But very few studies have paid attention to the effects of neonatal peripheral sensory nerve damage on synaptic wiring of the central nervous system (CNS) circuits. Peripheral somatosensory nerves differ from other special sensory afferents in that they are more prone to crush or severance because of their locations in the body. Unlike the visual and auditory afferents, these nerves show regenerative capabilities after damage. Uniquely, damage to a somatosensory peripheral nerve does not only block activity incoming from the sensory receptors but also mediates injury-induced neuro- and glial chemical signals to the brain through the uninjured central axons of the primary sensory neurons. These chemical signals can have both far more and longer lasting effects than sensory blockade alone. Here we review studies which focus on the consequences of neonatal peripheral sensory nerve damage in the principal sensory nucleus of the brainstem trigeminal complex. PMID:25956829

  5. Natural history of sensory nerve recovery after cutaneous nerve injury following foot and ankle surgery.

    PubMed

    Bai, Lu; Han, Yan-Ni; Zhang, Wen-Tao; Huang, Wei; Zhang, Hong-Lei

    2015-01-01

    Cutaneous nerve injury is the most common complication following foot and ankle surgery. However, clinical studies including long-term follow-up data after cutaneous nerve injury of the foot and ankle are lacking. In the current retrospective study, we analyzed the clinical data of 279 patients who underwent foot and ankle surgery. Subjects who suffered from apparent paresthesia in the cutaneous sensory nerve area after surgery were included in the study. Patients received oral vitamin B12 and methylcobalamin. We examined final follow-up data of 17 patients, including seven with sural nerve injury, five with superficial peroneal nerve injury, and five with plantar medial cutaneous nerve injury. We assessed nerve sensory function using the Medical Research Council Scale. Follow-up immediately, at 6 weeks, 3, 6 and 9 months, and 1 year after surgery demonstrated that sensory function was gradually restored in most patients within 6 months. However, recovery was slow at 9 months. There was no significant difference in sensory function between 9 months and 1 year after surgery. Painful neuromas occurred in four patients at 9 months to 1 year. The results demonstrated that the recovery of sensory function in patients with various cutaneous nerve injuries after foot and ankle surgery required at least 6 months. PMID:25788928

  6. Leptin-sensitive sensory nerves innervate white fat.

    PubMed

    Murphy, Keegan T; Schwartz, Gary J; Nguyen, Ngoc Ly T; Mendez, Jennifer M; Ryu, Vitaly; Bartness, Timothy J

    2013-06-15

    Leptin, the primary white adipose tissue (WAT) adipokine, is thought to convey lipid reserve information to the brain via the circulation. Because WAT responds to environmental/internal signals in a fat pad-specific (FPS) manner, systemic signals such as leptin would fail to communicate such distinctive information. Saturation of brain leptin transport systems also would fail to convey increased lipid levels beyond that point. WAT possesses sensory innervation exemplified by proven sensory-associated peptides in nerves within the tissue and by viral sensory nerve-specific transneuronal tract tracer, H129 strain of herpes simplex virus 1 labeling of dorsal root ganglia (DRG) pseudounipolar neurons, spinal cord and central sensory circuits. Leptin as a paracrine factor activating WAT sensory innervation could supply the brain with FPS information. Therefore, we tested for and found the presence of the long form of the leptin receptor (Ob-Rb) on DRG pseudounipolar neurons immunohistochemically labeled after injections of Fluorogold, a retrograde tract tracer, into inguinal WAT (IWAT). Intra-IWAT leptin injections (300 ng) significantly elevated IWAT nerve spike rate within 5 min and persisted for at least 30 min. Intra-IWAT leptin injections also induced significant c-Fos immunoreactivity (ir), indicating neural activation across DRG pseudounipolar sensory neurons labeled with Fluorogold IWAT injections. Intraperitoneal leptin injection did not increase c-Fos-ir in DRG or the arcuate nucleus, nor did it increase arcuate signal transducer and activator of transcription 3 phosphorylation-ir. Collectively, these results strongly suggest that endogenous leptin secreted from white adipocytes functions as a paracrine factor to activate spinal sensory nerves innervating the tissue. PMID:23612999

  7. Sensory Nerve Induced Inflammation Contributes to Heterotopic Ossification

    PubMed Central

    Salisbury, Elizabeth; Rodenberg, Eric; Sonnet, Corinne; Hipp, John; Gannon, Francis H.; Vadakkan, Tegy J.; Dickinson, Mary E.; Olmsted-Davis, Elizabeth A.; Davis, Alan R.

    2012-01-01

    Heterotopic ossification (HO), or bone formation in soft tissues, is often the result of traumatic injury. Much evidence has linked the release of BMPs (bone morphogenetic proteins) upon injury to this process. HO was once thought to be a rare occurrence, but recent statistics from the military suggest that as many as 60% of traumatic injuries, resulting from bomb blasts, have associated HO. In this study, we attempt to define the role of peripheral nerves in this process. Since BMP2 has been shown previously to induce release of the neuroinflammatory molecules, substance P (SP) and calcitonin gene related peptide (CGRP), from peripheral, sensory neurons, we examined this process in vivo. SP and CGRP are rapidly expressed upon delivery of BMP2 and remain elevated throughout bone formation. In animals lacking functional sensory neurons (TRPV1?/?), BMP2-mediated increases in SP and CGRP were suppressed as compared to the normal animals, and HO was dramatically inhibited in these deficient mice, suggesting that neuroinflammation plays a functional role. Mast cells, known to be recruited by SP and CGRP, were elevated after BMP2 induction. These mast cells were localized to the nerve structures and underwent degranulation. When degranulation was inhibited using cromolyn, HO was again reduced significantly. Immunohistochemical analysis revealed nerves expressing the stem cell markers nanog and Klf4, as well as the osteoblast marker osterix, after BMP2 induction, in mice treated with cromolyn. The data collectively suggest that BMP2 can act directly on sensory neurons to induce neurogenic inflammation, resulting in nerve remodeling and the migration/release of osteogenic and other stem cells from the nerve. Further, blocking this process significantly reduces HO, suggesting that the stem cell population contributes to bone formation. PMID:21678472

  8. The importance of sensory nerve endings as sites of drug action.

    PubMed

    Ginzel, K H

    1975-01-01

    The role that sensory nerve endings can play in drug action and the strategy used for its experimental analysis and proof is first exemplified by three effects of nicotine which are seen when the lowest effective doses of the drug are given intravenously in the cat: (1) a vasopressor effect due to arterial chemoreceptor stimulation; (2) a triad of bradycardia, hypotension and apnea, and (3) a depressant effect upon somatic motor activity, both of which are traced to vagal afferent endings in the pulmonary circulation. While receptors in the lung are responsible at least for the initial phase of the reflex responses listed in (2) and (3), sensory endings in heart, aorta, and carotid sinus region may be recruited into action as the drug reaches them. Several of these reflex effects can also be elicited by other sensory stimulant agents such as phenyldiguanide, 5-hydroxytryptamine, and veratrum alkaloids. In the second part, a general outline is given of what may be classified as 'Afferent Pharmacology', dealing with drug action upon sensory receptors and with the resulting remote drug effects. The action upon sensory receptors can either be a direct one ('primary' drug effect) consisting of stimulation, sensitization, desensitization, depression or combinations thereof, or an indirect ('secondary') effect brought about by a variety of drug-induced changes in the tissues surrounding the receptors. Depending on the nature of the primary or secondary action, the remote drug effect can be either an initiation, modification or impairment of those reflexes which have their origin in the sensory endings acted upon. Indeed, the grossly observable pharmacological actions of 'afferent drugs' are generally those relating to the reflex response. To avoid blurring of the boundaries of afferent pharmacology, drugs acting on central synapses of reflex pathways, or on the elaborate efferent control system of afferent input, are not included. A discussion follows of the topics of investigation, the influence of experimental conditions and anesthesia, various approaches and methods, the physiological and pharmacological importance of inquiry in this area, and some of the therapeutic aspects. Finally, brief mention is made of certain features and problems which appear to be characteristic of afferent pharmacology. PMID:1099463

  9. Uses of skin biopsy for sensory and autonomic nerve assessment.

    PubMed

    Myers, M Iliza; Peltier, Amanda C

    2013-01-01

    Skin biopsy is a valuable diagnostic tool for small-fiber-predominant neuropathy by the quantification of intraepidermal nerve fiber density (IENFD). It has the unique advantage of being a minimally invasive procedure with the potential for longitudinal evaluation of both sensory and autonomic fibers. Unmyelinated small fibers are not otherwise quantified objectively with such a level of sensitivity as has been reported with IENFD. Recent advances include an expansion of the skin punch biopsy technique to evaluate larger myelinated fibers and mechanoreceptors, and recent work has also focused on additional methods of quantifying dermal fibers and densely innervated autonomic structures. This review discusses current work using skin biopsy for the pathologic analysis of peripheral nerve fibers in neuropathy of various causes as well as its use in clinical trials. PMID:23250768

  10. Functional Recovery of Denervated Skeletal Muscle with Sensory or Mixed Nerve Protection: A Pilot Study

    PubMed Central

    Li, Qing Tian; Zhang, Pei Xun; Yin, Xiao Feng; Han, Na; Kou, Yu Hui; Deng, Jiu Xu; Jiang, Bao Guo

    2013-01-01

    Functional recovery is usually poor following peripheral nerve injury when reinnervation is delayed. Early innervation by sensory nerve has been indicated to prevent atrophy of the denervated muscle. It is hypothesized that early protection with sensory axons is adequate to improve functional recovery of skeletal muscle following prolonged denervation of mixed nerve injury. In this study, four groups of rats received surgical denervation of the tibial nerve. The proximal and distal stumps of the tibial nerve were ligated in all animals except for those in the immediate repair group. The experimental groups underwent denervation with nerve protection of peroneal nerve (mixed protection) or sural nerve (sensory protection). The experimental and unprotected groups had a stage II surgery in which the trimmed proximal and distal tibial nerve stumps were sutured together. After 3 months of recovery, electrophysiological, histological and morphometric parameters were assessed. It was detected that the significant muscle atrophy and a good preserved structure of the muscle were observed in the unprotected and protective experimental groups, respectively. Significantly fewer numbers of regenerated myelinated axons were observed in the sensory-protected group. Enhanced recovery in the mixed protection group was indicated by the results of the muscle contraction force tests, regenerated myelinated fiber, and the results of the histological analysis. Our results suggest that early axons protection by mixed nerve may complement sensory axons which are required for promoting functional recovery of the denervated muscle natively innervated by mixed nerve. PMID:24244555

  11. Photostimulation of sensory neurons of the rat vagus nerve

    NASA Astrophysics Data System (ADS)

    Rhee, Albert Y.; Li, Gong; Wells, Jonathon; Kao, Joseph P. Y.

    2008-02-01

    We studied the effect of infrared (IR) stimulation on rat sensory neurons. Primary sensory neurons were prepared by enzymatic dissociation of the inferior (or "nodose") ganglia from the vagus nerves of rats. The 1.85-?m output of a diode laser, delivered through a 200-?m silica fiber, was used for photostimulation. Nodose neurons express the vanilloid receptor, TRPV1, which is a non-selective cation channel that opens in response to significant temperature jumps above 37 C. Opening TRPV1 channels allows entry of cations, including calcium (Ca 2+), into the cell to cause membrane depolarization. Therefore, to monitor TRPV1 activation consequent to photostimulation, we used fura-2, a fluorescent Ca 2+ indicator, to monitor the rise in intracellular Ca 2+ concentration ([Ca 2+]i). Brief trains of 2-msec IR pulses activated TRPV1 rapidly and reversibly, as evidenced by transient rises in [Ca 2+]i (referred to as Ca 2+ transients). Consistent with the Ca 2+ transients arising from influx of Ca 2+, identical photostimulation failed to evoke Ca 2+ responses in the absence of extracellular Ca 2+. Furthermore, the photo-induced Ca 2+ signals were abolished by capsazepine, a specific blocker of TRPV1, indicating that the responses were indeed mediated by TRPV1. We discuss the feasibility of using focal IR stimulation to probe neuronal circuit properties in intact neural tissue, and compare IR stimulation with another photostimulation technique-focal photolytic release of "caged" molecules.

  12. Improved functional recovery of denervated skeletal muscle after temporary sensory nerve innervation.

    PubMed

    Bain, J R; Veltri, K L; Chamberlain, D; Fahnestock, M

    2001-01-01

    Prolonged muscle denervation results in poor functional recovery after nerve repair. The possible protective effect of temporary sensory innervation of denervated muscle, prior to motor nerve repair, has been examined in the rat. Soleus and gastrocnemius muscles were denervated by cutting the tibial nerve, and the peroneal nerve was then sutured to the transected distal tibial nerve stump either immediately or after two, four or six months. In half of the animals with delayed repair, the saphenous (sensory) nerve was temporarily attached to the distal nerve stump. Muscles were evaluated three months after the peroneal-to-tibial union, and were compared with each other, with unoperated control muscles and with untreated denervated muscles. After four to six months of sensory "protection", gastrocnemius muscles weighed significantly more than unprotected muscles, and both gastrocnemius and soleus muscles exhibited better preservation of their structure, with less fiber atrophy and connective tissue hyperplasia. The maximum compound action potentials were significantly larger in gastrocnemius and soleus muscles following sensory protection, irrespective of the delay in motor nerve union. Isometric force, although less than in control animals and in those with immediate nerve repair, remained reasonably constant after sensory protection, while in unprotected muscles there was a progressive and significant decline as the period of denervation lengthened. We interpret these results as showing that, although incapable of forming excitable neuromuscular junctions, sensory nerves can nevertheless exert powerful trophic effects on denervated muscle fibers. We propose that these findings indicate a useful strategy for improving the outcome of peripheral nerve surgery. PMID:11246164

  13. Sensory Protection of Rat Muscle Spindles following Peripheral Nerve Injury and Reinnervation

    PubMed Central

    Elsohemy, Amal; Butler, Richard; Bain, James R.; Fahnestock, Margaret

    2012-01-01

    Background Skeletal muscle structure and function are dependent on intact Richard Butler, Ph.D. innervation. Prolonged muscle denervation results in irreversible muscle fiber James R. Bain, M.D. atrophy, connective tissue hyperplasia, and deterioration of muscle spindles, Margaret Fahnestock, Ph.D. specialized sensory receptors necessary for proper skeletal muscle function. The protective effect of temporary sensory innervation on denervated muscle, before motor nerve repair, has been shown in the rat. Sensory-protected muscles exhibit less fiber atrophy and connective tissue hyperplasia and maintain greater functional capacity than denervated muscles. The purpose of this study was to determine whether temporary sensory innervation also protects muscle spindles from degeneration. Methods Rat tibial nerve was transected and repaired with either the saphenous or the original transected nerve. Negative controls remained denervated. After 3 to 6 months, the electrophysiologic response of the nerve to stretch in the rat gastrocnemius muscle was measured (n = 3 per group). After the animals were euthanized, the gastrocnemius muscle was removed, sectioned, stained, and examined for spindle number (n = 3 per group) and morphology (one rat per group). Immunohistochemical assessment of muscle spindle innervation was examined in four additional animals. Results Significant deterioration of muscle spindles was seen in denervated muscle, whereas in muscle reinnervated with the tibial or the saphenous nerve, spindle number and morphology were improved. Histologic and functional evidence of spindle reinnervation by the sensory nerve was obtained. Conclusion These findings add to the known means by which motor or sensory nerves exert protective effects on denervated muscle, and further promote the use of sensory protection for improving the outcome after peripheral nerve injury. PMID:19952642

  14. Effect of long-term implanted nerve cuff electrodes on the electrophysiological properties of human sensory nerves.

    PubMed

    Slot, P J; Selmar, P; Rasmussen, A; Sinkjaer, T

    1997-03-01

    During a long-term implantation (307 days) of a tripolar split cuff electrode around the palmar digital nerve to the radial side of the left index finger, branching off the median nerve in a medullary lesioned C6 patient, the physiological state of the nerve was intensively monitored. The resulting sensory nerve action potential (SNAP) amplitude was recorded, using both near-nerve electrodes and the implanted cuff electrode. The SNAP amplitude declined within 10 days to approximately 50% of the first SNAP cuff amplitude measured on Day 2 after implantation and recovered to the initial amplitude within 3 months. The SNAP amplitude measurements made with near-nerve electrodes were consistent with the cuff results; the SNAP conduction velocity (CV) recorded by the near-nerve electrodes and the cuff electrode was constant during the whole implantation period. This is in agreement with the results from two other patients: one with a cuff implanted around the sural nerve, and the other with a cuff implanted around a branch of the tibial nerve. These results and animals studies show that the cuff electrode is an electrically stable neural-electrical transducer. PMID:9148706

  15. Neurilemmoma of Deep Peroneal Nerve Sensory Branch : Thermographic Findings with Compression Test

    PubMed Central

    Ryu, Seung Jun

    2015-01-01

    We report a case of neurilemmoma of deep peroneal nerve sensory branch that triggered sensory change with compression test on lower extremity. After resection of tumor, there are evoked thermal changes on pre- and post-operative infrared (IR) thermographic images. A 52-year-old female presented with low back pain, sciatica, and sensory change on the dorsal side of the right foot and big toe that has lasted for 9 months. She also presented with right tibial mass sized 1.2 cm by 1.4 cm. Ultrasonographic imaging revealed a peripheral nerve sheath tumor arising from the peroneal nerve. IR thermographic image showed hyperthermia when the neurilemoma induced sensory change with compression test on the fibular area, dorsum of foot, and big toe. After surgery, the symptoms and thermographic changes were relieved and disappeared. The clinical, surgical, radiographic, and thermographic perspectives regarding this case are discussed. PMID:26539275

  16. Neurilemmoma of Deep Peroneal Nerve Sensory Branch : Thermographic Findings with Compression Test.

    PubMed

    Ryu, Seung Jun; Zhang, Ho Yeol

    2015-09-01

    We report a case of neurilemmoma of deep peroneal nerve sensory branch that triggered sensory change with compression test on lower extremity. After resection of tumor, there are evoked thermal changes on pre- and post-operative infrared (IR) thermographic images. A 52-year-old female presented with low back pain, sciatica, and sensory change on the dorsal side of the right foot and big toe that has lasted for 9 months. She also presented with right tibial mass sized 1.2 cm by 1.4 cm. Ultrasonographic imaging revealed a peripheral nerve sheath tumor arising from the peroneal nerve. IR thermographic image showed hyperthermia when the neurilemoma induced sensory change with compression test on the fibular area, dorsum of foot, and big toe. After surgery, the symptoms and thermographic changes were relieved and disappeared. The clinical, surgical, radiographic, and thermographic perspectives regarding this case are discussed. PMID:26539275

  17. Myelinated sensory and alpha motor axon regeneration in peripheral nerve neuromas

    NASA Technical Reports Server (NTRS)

    Macias, M. Y.; Lehman, C. T.; Sanger, J. R.; Riley, D. A.

    1998-01-01

    Histochemical staining for carbonic anhydrase and cholinesterase (CE) activities was used to analyze sensory and motor axon regeneration, respectively, during neuroma formation in transected and tube-encapsulated peripheral nerves. Median-ulnar and sciatic nerves in the rodent model permitted testing whether a 4 cm greater distance of the motor neuron soma from axotomy site or intrinsic differences between motor and sensory neurons influenced regeneration and neuroma formation 10, 30, and 90 days later. Ventral root radiculotomy confirmed that CE-stained axons were 97% alpha motor axons. Distance significantly delayed axon regeneration. When distance was negligible, sensory axons grew out sooner than motor axons, but motor axons regenerated to a greater quantity. These results indicate regeneration differences between axon subtypes and suggest more extensive branching of motor axons within the neuroma. Thus, both distance from injury site to soma and inherent motor and sensory differences should be considered in peripheral nerve repair strategies.

  18. Degeneration of proprioceptive sensory nerve endings in mice harboring amyotrophic lateral sclerosis-causing mutations.

    PubMed

    Vaughan, Sydney K; Kemp, Zachary; Hatzipetros, Theo; Vieira, Fernando; Valdez, Gregorio

    2015-12-01

    Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease that primarily targets the motor system. Although much is known about the effects of ALS on motor neurons and glial cells, little is known about its effect on proprioceptive sensory neurons. This study examines proprioceptive sensory neurons in mice harboring mutations associated with ALS, in SOD1(G93A) and TDP43(A315T) transgenic mice. In both transgenic lines, we found fewer proprioceptive sensory neurons containing fluorescently tagged cholera toxin in their soma five days after injecting this retrograde tracer into the tibialis anterior muscle. We asked whether this is due to neuronal loss or selective degeneration of peripheral nerve endings. We found no difference in the total number and size of proprioceptive sensory neuron soma between symptomatic SOD1(G93A) and control mice. However, analysis of proprioceptive nerve endings in muscles revealed early and significant alterations at Ia/II proprioceptive nerve endings in muscle spindles before the symptomatic phase of the disease. Although these changes occur alongside those at ?-motor axons in SOD1(G93A) mice, Ia/II sensory nerve endings degenerate in the absence of obvious alterations in ?-motor axons in TDP43(A315T) transgenic mice. We next asked whether proprioceptive nerve endings are similarly affected in the spinal cord and found that nerve endings terminating on ?-motor neurons are affected during the symptomatic phase and after peripheral nerve endings begin to degenerate. Overall, we show that Ia/II proprioceptive sensory neurons are affected by ALS-causing mutations, with pathological changes starting at their peripheral nerve endings. J. Comp. Neurol. 523:2477-2494, 2015. © 2015 Wiley Periodicals, Inc. PMID:26424446

  19. Degeneration of proprioceptive sensory nerve endings in mice harboring amyotrophic lateral sclerosis-causing mutations.

    PubMed

    Vaughan, Sydney K; Kemp, Zachary; Hatzipetros, Theo; Vieira, Fernando; Valdez, Gregorio

    2015-12-01

    Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease that primarily targets the motor system. Although much is known about the effects of ALS on motor neurons and glial cells, little is known about its effect on proprioceptive sensory neurons. This study examines proprioceptive sensory neurons in mice harboring mutations associated with ALS, in SOD1(G93A) and TDP43(A315T) transgenic mice. In both transgenic lines, we found fewer proprioceptive sensory neurons containing fluorescently tagged cholera toxin in their soma five days after injecting this retrograde tracer into the tibialis anterior muscle. We asked whether this is due to neuronal loss or selective degeneration of peripheral nerve endings. We found no difference in the total number and size of proprioceptive sensory neuron soma between symptomatic SOD1(G93A) and control mice. However, analysis of proprioceptive nerve endings in muscles revealed early and significant alterations at Ia/II proprioceptive nerve endings in muscle spindles before the symptomatic phase of the disease. Although these changes occur alongside those at ?-motor axons in SOD1(G93A) mice, Ia/II sensory nerve endings degenerate in the absence of obvious alterations in ?-motor axons in TDP43(A315T) transgenic mice. We next asked whether proprioceptive nerve endings are similarly affected in the spinal cord and found that nerve endings terminating on ?-motor neurons are affected during the symptomatic phase and after peripheral nerve endings begin to degenerate. Overall, we show that Ia/II proprioceptive sensory neurons are affected by ALS-causing mutations, with pathological changes starting at their peripheral nerve endings. PMID:26136049

  20. Sensory cutaneous nerve fine-needle aspiration in Hansen's disease: A retrospective analysis of our experience

    PubMed Central

    Prasoon, Dev; Mandal, Swapan Kumar; Agrawal, Parimal

    2015-01-01

    Background: Leprosy affects peripheral nerves. As Mycobacterium leprae has unique tropism for Schwann cells, thickened sensory cutaneous nerves provide an easy target for the detection of lepra bacilli and other changes associated with the disease. Materials and Methods: The data of patients with sensory cutaneous nerve involvement were retrieved from our record for the period January 2006 to December 2014. The hematoxylin and eosin (H and E)- and May-Grünwald-Giemsa (MGG)-stained slides were screened for Schwann cells, granuloma, and necrosis. Modified Ziehl-Neelsen (ZN)-stained smears were searched for lepra bacilli and globi. Morphological index was calculated in multibacillary lesions. Result: Twenty-nine sensory cutaneous nerves were aspirated in 23 patients. While 15 cases showed skin and nerve involvement, 8 cases showed only nerve involvement. Terminal cutaneous branch of the radial nerve was most often aspirated. No motor loss was observed after aspiration. Five cytologic pictures were seen — Epithelioid cell granuloma only in 6 cases, epithelioid cell granuloma with necrosis in 1 case, epithelioid cell granuloma with lepra bacilli in 3 cases, necrosis with lepra bacilli in 1 case, and only lepra bacilli in 12 cases. Morphological index ranged from 20% to 80%. Conclusion: Sensory cutaneous nerve fine-needle aspiration (FNA) is a feasible, viable, effective, and safe procedure. It adds to diagnostic FNA yield in patients with concomitant skin involvement and offers a way to evaluate patients with only nerve involvement. Calculation of morphological index allows prognostication and may have a role in assessing response to therapy and/or relapse. PMID:26729977

  1. Effect of pulsed infrared lasers on neural conduction and axoplasmic transport in sensory nerves

    NASA Astrophysics Data System (ADS)

    Wesselmann, Ursula; Rymer, William Z.; Lin, Shien-Fong

    1990-06-01

    Over the past ten years there has been an increasing interest in the use of lasers for neurosurgical and neurological procedures. Novel recent applications range from neurosurgical procedures such as dorsal root entry zone lesions made with argon and carbon dioxide microsurgical lasers to pain relief by low power laser irradiation of the appropriate painful nerve or affected region1 '2 However, despite the widespread clinical applications of laser light, very little is known about the photobiological interactions between laser light and nervous tissue. The present studies were designed to evaluate the effects of pulsed Nd:YAG laser light on neural impulse conduction and axoplasmic transport in sensory nerves in rats and cats. Our data indicate that Q-switched Nd:YAG laser irradiation can induce a preferential impairment of (1) the synaptic effects of small afferent fibers on dorsal horn cells in the spinal cord and of (2) small slow conducting sensory nerve fibers in dorsal roots and peripheral nerves. These results imply that laser light might have selective effects on impulse conduction in slow conducting sensory nerve fibers. In agreement with our elecirophysiological observations recent histological data from our laboratory show, that axonal transport of the enzyme horseradish peroxidase is selectively impaired in small sensory nerve fibers. In summary these data indicate, that Q-switched Nd:YAG laser irradiation can selectively impair neural conduction and axoplasmic transport in small sensory nerve fibers as compared to fast conducting fibers. A selective influence of laser irradiation on slow conducting fibers could have important clinical applications, especially for the treatment of chronic pain.

  2. Long-term changes in neurotrophic factor expression in distal nerve stump following denervation and reinnervation with motor or sensory nerve

    PubMed Central

    Michalski, B.; Bain, J. R.; Fahnestock, M.

    2012-01-01

    Several factors have been proposed to account for poor motor recovery after prolonged denervation, including motor neuron cell death and incomplete or poor regeneration of motor fibers into the muscle. Both may result from failure of the muscle and the distal motor nerve stump to continue expression of neurotrophic factors following delayed muscle reinnervation. This study investigated whether regenerating motor or sensory axons modulate distal nerve neurotrophic factor expression. We found that transected distal tibial nerve up-regulated brain-derived neurotrophic factor (BDNF) and glial cell line-derived neurotrophic factor (GDNF) mRNA, down-regulated neuro-trophin-3 and ciliary neurotrophic factor mRNA, and that although these levels returned to normal with regeneration, the chronically denervated distal nerve stump continued to express these neurotrophic factors for at least 6 months following injury. A sensory nerve (the cutaneous saphenous nerve) sutured to distal tibial nerve lowered injury-induced BDNF and GDNF mRNA levels in distal stump, but repair with a mixed nerve (peroneal, containing muscle and cutaneous axons) was more effective. Repair with sensory or mixed nerves did not affect nerve growth factor or neurotrophin-3 expression. Thus, distal nerve contributed to a neurotrophic environment for nerve regeneration for at least 6 months, and sensory nerve repair helped normalize distal nerve neurotrophic factor mRNA expression following denervation. Furthermore, as BDNF and GDNF levels in distal stump increased following denervation and returned to control levels following reinnervation, their levels serve as markers for the status of regeneration by either motor or sensory nerve. PMID:18194437

  3. Long-term changes in neurotrophic factor expression in distal nerve stump following denervation and reinnervation with motor or sensory nerve.

    PubMed

    Michalski, B; Bain, J R; Fahnestock, M

    2008-05-01

    Several factors have been proposed to account for poor motor recovery after prolonged denervation, including motor neuron cell death and incomplete or poor regeneration of motor fibers into the muscle. Both may result from failure of the muscle and the distal motor nerve stump to continue expression of neurotrophic factors following delayed muscle reinnervation. This study investigated whether regenerating motor or sensory axons modulate distal nerve neurotrophic factor expression. We found that transected distal tibial nerve up-regulated brain-derived neurotrophic factor (BDNF) and glial cell line-derived neurotrophic factor (GDNF) mRNA, down-regulated neurotrophin-3 and ciliary neurotrophic factor mRNA, and that although these levels returned to normal with regeneration, the chronically denervated distal nerve stump continued to express these neurotrophic factors for at least 6 months following injury. A sensory nerve (the cutaneous saphenous nerve) sutured to distal tibial nerve lowered injury-induced BDNF and GDNF mRNA levels in distal stump, but repair with a mixed nerve (peroneal, containing muscle and cutaneous axons) was more effective. Repair with sensory or mixed nerves did not affect nerve growth factor or neurotrophin-3 expression. Thus, distal nerve contributed to a neurotrophic environment for nerve regeneration for at least 6 months, and sensory nerve repair helped normalize distal nerve neurotrophic factor mRNA expression following denervation. Furthermore, as BDNF and GDNF levels in distal stump increased following denervation and returned to control levels following reinnervation, their levels serve as markers for the status of regeneration by either motor or sensory nerve. PMID:18194437

  4. Neuromas and gaps of sensory nerves of the hand: management using vein conduits.

    PubMed

    Malizos, K N; Dailiana, Z H; Anastasiou, E A; Sarmas, I; Soucacos, P N

    1997-07-01

    This study analyzed the efficacy of an interposed vein conduit graft in eliminating symptoms of painful neuroma of sensory nerves of the hand and preventing recurrence after excising the pathologic tissue and bridging the concomitant gap with the distal nerve segment. Twenty-three patients underwent reconstruction of 25 palmar sensory nerve gaps ranging from 12 mm to 28 mm, as well as 2 dorsal gaps of 32 mm and 35 mm, respectively. Eighteen patients had symptomatic painful neuromas. Subjective and objective evaluation criteria were employed for assessment and were compared with data obtained from primary direct suturing in 25 digital nerves of 21 patients. Electrophysiologic measurements, including sensory nerve action potential and conduction velocity, were similar, with both groups having values significantly lower than normal control values. Two-point discrimination measurements were slightly inferior for the vein conduit-reconstructed nerves compared with results attained after direct suturing. However, neuroma symptoms were eliminated, and in combination with the return of adequate sensibility, all but 1 patient resumed full hand function. PMID:9247655

  5. White adipose tissue sensory nerve denervation mimics lipectomy-induced compensatory increases in adiposity.

    PubMed

    Shi, Haifei; Bartness, Timothy J

    2005-08-01

    The sensory innervation of white adipose tissue (WAT) is indicated by the labeling of sensory bipolar neurons in the dorsal root ganglion after retrograde dye placement into WAT. In addition, immunoreactivity (ir) for sensory-associated neuropeptides such as calcitonin gene-related peptide (CGRP) and substance P in WAT pads also supports the notion of WAT sensory innervation. The function of this sensory innervation is unknown but could involve conveying the degree of adiposity to the brain. In tests of total body fat regulation, partial surgical lipectomy triggers compensatory increases in the mass of nonexcised WAT, ultimately resulting in restoration of total body fat levels in Siberian hamsters and other animals. The signal that triggers this compensation is unknown but could involve disruption of WAT sensory innervation that accompanies lipectomy. Therefore, a local and selective sensory denervation was accomplished by microinjecting the sensory nerve neurotoxin capsaicin bilaterally into epididymal WAT (EWAT) of Siberian hamsters, whereas controls received vehicle injections. Additional hamsters had bilateral EWAT lipectomy (EWATx) or sham lipectomy. As seen previously, EWATx resulted in significantly increased retroperitoneal WAT (RWAT) and inguinal WAT (IWAT) masses. Capsaicin treatment significantly decreased CGRP- but not tyrosine hydroxylase-ir, attesting to the diminished and selective sensory innervation. Capsaicin-treated hamsters also had increased RWAT and, to a lesser degree, IWAT mass largely mimicking the WAT mass increases seen after lipectomy. Collectively, these data suggest the possibility that information related to peripheral lipid stores may be conveyed to the brain via the sensory innervation of WAT. PMID:15860651

  6. Photodamage to the cutaneous sensory nerves: role in photoaging and carcinogenesis of the skin?

    PubMed

    Legat, Franz J; Wolf, Peter

    2006-02-01

    Chronic exposure to ultraviolet radiation (UVR) plays a significant role in aging and carcinogenesis of the skin. Sensory nerve fibers densely innervate all layers of the skin and get in close anatomical as well as functional contact with cellular components of the epidermis and dermis. In this review, we address the impact of acute and chronic UVR exposure on the cutaneous sensory nervous system and its mediators. We suggest that skin cell-derived nerve growth factor (NGF) and skin nerve-derived neuropeptides such as substance P (SP) and calcitonin gene-related peptide (CGRP) may play a central role in intrinsic aging as well as extrinsic (photo-) aging of the skin. In addition, we discuss the possible role of these mediators in photocarcinogenesis. PMID:16465302

  7. Modulation of sympathetic nerve activity by perivascular sensory nerves in the arterioles of the guinea-pig small intestine.

    PubMed

    Coffa; Kotecha

    1999-09-24

    OBJECTIVE: The aim of this study was to assess the role of perivascular sensory nerves in modulating constrictions of intestinal submucosal arterioles. METHODS: Arteriole constrictions were induced either by nerve released adenosine 5'-triphosphate (ATP) or exogenous ATP or phenylephrine (PE). Individual nerve shocks were used to elicit excitatory junction potentials (EJPs) in the arteriole smooth muscle whereas trains of stimuli were used to evoke transient constrictions of the arteriole. Effects of the sensory neurotoxin, capsaicin, were examined on constrictions and EJPs. RESULTS: Pre-treatment of the arteriole preparation with capsaicin did not cause any significant change in the amplitude of arteriole constrictions to exogenously applied ATP or PE. However, there was a significant increase in the amplitude of neurally evoked arteriole constrictions and EJPs, without a significant change in the decay time constant (tau(decay)) of the EJPs. Exogenous application of calcitonin gene related peptide (CGRP) significantly decreased tau(decay) of the EJPs without affecting their amplitude, whereas substance P (SP) significantly decreased the amplitude of EJPs without affecting tau(decay). Both, CGRP and SP, decreased the amplitude of neurally evoked and ATP induced constrictions. Whilst the inhibitory effects of CGRP on evoked and ATP induced constrictions were not significantly different, the reduction in evoked constrictions obtained with SP was significantly greater than the reduction in ATP induced constrictions. SP antagonist significantly increased the amplitude of neurally evoked constrictions. CONCLUSIONS: It is concluded that capsaicin-sensitive afferents inhibit the release of transmitter from perivascular sympathetic nerves via the prejunctional modulatory action of SP. The other putative sensory neurotransmitter, CGRP, appears to act postjunctionally on the arteriole smooth muscle. PMID:11130956

  8. Sensory neural conduction of median nerve from digits and palm stimulation in carpal tunnel syndrome.

    PubMed

    Rossi, S; Giannini, F; Passero, S; Paradiso, C; Battistini, N; Cioni, R

    1994-10-01

    The median sensory nerve conduction between ring finger and wrist is a suitable parameter for early detection of carpal tunnel syndrome (CTS), although shorter segments of median nerve have also been proposed for the same goal. In order to assess the relative diagnostic value of the sensory nerve conduction velocity (SNCV) of the third palmar branch versus the SNCV of the second palmar branch, generally performed until now, we studied 62 patients with typical signs and symptoms of CTS. The following parameters were evaluated by surface recording: orthodromic SNCVs in digit-wrist segments for median (index = M2, third = M3 and ring = M4 fingers), ulnar (fourth = U4 finger) and radial (thumb = R1) nerves; SNCVs in palm-wrist segments by surface bipolar stimulation at each metacarpo-phalangeal interspace (second = P2 and third = P3 for the median nerve and fourth = P4 for the ulnar nerve); and distal motor latencies of the median and ulnar nerves. No responses at the wrist were recorded in 22.6% of patients after digital stimulation of M4, whereas the SNCV of P3, the palmar nerve branch arising from digital nerves of the medial side of M3 and the lateral side of M4, was measurable in 93.5% of patients. As significantly expressed (P < 0.001) by the increased ratio of the mean values of P2 and P3 in CTS patients, the SNCV of P3 decreased more frequently and to a greater extent than the SNCV of P2. PMID:7525240

  9. Menthol Enhances the Desensitization of Human ?3?4 Nicotinic Acetylcholine Receptors.

    PubMed

    Ton, Hoai T; Smart, Amanda E; Aguilar, Brittany L; Olson, Thao T; Kellar, Kenneth J; Ahern, Gerard P

    2015-08-01

    The ?3?4 nicotinic acetylcholine receptor (nAChR) subtype is widely expressed in the peripheral and central nervous systems, including in airway sensory nerves. The nAChR subtype transduces the irritant effects of nicotine in tobacco smoke and, in certain brain areas, may be involved in nicotine addiction and/or withdrawal. Menthol, a widely used additive in cigarettes, is a potential analgesic and/or counterirritant at sensory nerves and may also influence nicotine's actions in the brain. We examined menthol's effects on recombinant human ?3?4 nAChRs and native nAChRs in mouse sensory neurons. Menthol markedly decreased nAChR activity as assessed by Ca(2+) imaging, (86)Rb(+) efflux, and voltage-clamp measurements. Coapplication of menthol with acetylcholine or nicotine increased desensitization, demonstrated by an increase in the rate and magnitude of the current decay and a reduction of the current integral. These effects increased with agonist concentration. Pretreatment with menthol followed by its washout did not affect agonist-induced desensitization, suggesting that menthol must be present during the application of agonist to augment desensitization. Notably, menthol acted in a voltage-independent manner and reduced the mean open time of single channels without affecting their conductance, arguing against a simple channel-blocking effect. Further, menthol slowed or prevented the recovery of nAChRs from desensitization, indicating that it probably stabilizes a desensitized state. Moreover, menthol at concentrations up to 1 mM did not compete for the orthosteric nAChR binding site labeled by [(3)H]epibatidine. Taken together, these data indicate that menthol promotes desensitization of ?3?4 nAChRs by an allosteric action. PMID:25964258

  10. The relationship of nerve fibre pathology to sensory function in entrapment neuropathy.

    PubMed

    Schmid, Annina B; Bland, Jeremy D P; Bhat, Manzoor A; Bennett, David L H

    2014-12-01

    Surprisingly little is known about the impact of entrapment neuropathy on target innervation and the relationship of nerve fibre pathology to sensory symptoms and signs. Carpal tunnel syndrome is the most common entrapment neuropathy; the aim of this study was to investigate its effect on the morphology of small unmyelinated as well as myelinated sensory axons and relate such changes to somatosensory function and clinical symptoms. Thirty patients with a clinical and electrophysiological diagnosis of carpal tunnel syndrome [17 females, mean age (standard deviation) 56.4 (15.3)] and 26 age and gender matched healthy volunteers [18 females, mean age (standard deviation) 51.0 (17.3)] participated in the study. Small and large fibre function was examined with quantitative sensory testing in the median nerve territory of the hand. Vibration and mechanical detection thresholds were significantly elevated in patients with carpal tunnel syndrome (P<0.007) confirming large fibre dysfunction and patients also presented with increased thermal detection thresholds (P<0.0001) indicative of C and A?-fibre dysfunction. Mechanical and thermal pain thresholds were comparable between groups (P>0.13). A skin biopsy was taken from a median nerve innervated area of the proximal phalanx of the index finger. Immunohistochemical staining for protein gene product 9.5 and myelin basic protein was used to evaluate morphological features of unmyelinated and myelinated axons. Evaluation of intraepidermal nerve fibre density showed a striking loss in patients (P<0.0001) confirming a significant compromise of small fibres. The extent of Meissner corpuscles and dermal nerve bundles were comparable between groups (P>0.07). However, patients displayed a significant increase in the percentage of elongated nodes (P<0.0001), with altered architecture of voltage-gated sodium channel distribution. Whereas neither neurophysiology nor quantitative sensory testing correlated with patients' symptoms or function deficits, the presence of elongated nodes was inversely correlated with a number of functional and symptom related scores (P<0.023). Our findings suggest that carpal tunnel syndrome does not exclusively affect large fibres but is associated with loss of function in modalities mediated by both unmyelinated and myelinated sensory axons. We also document for the first time that entrapment neuropathies lead to a clear reduction in intraepidermal nerve fibre density, which was independent of electrodiagnostic test severity. The presence of elongated nodes in the target tissue further suggests that entrapment neuropathies affect nodal structure/myelin well beyond the focal compression site. Interestingly, nodal lengthening may be an adaptive phenomenon as it inversely correlates with symptom severity. PMID:25348629

  11. The relationship of nerve fibre pathology to sensory function in entrapment neuropathy

    PubMed Central

    Schmid, Annina B.; Bland, Jeremy D. P.; Bhat, Manzoor A.

    2014-01-01

    Surprisingly little is known about the impact of entrapment neuropathy on target innervation and the relationship of nerve fibre pathology to sensory symptoms and signs. Carpal tunnel syndrome is the most common entrapment neuropathy; the aim of this study was to investigate its effect on the morphology of small unmyelinated as well as myelinated sensory axons and relate such changes to somatosensory function and clinical symptoms. Thirty patients with a clinical and electrophysiological diagnosis of carpal tunnel syndrome [17 females, mean age (standard deviation) 56.4 (15.3)] and 26 age and gender matched healthy volunteers [18 females, mean age (standard deviation) 51.0 (17.3)] participated in the study. Small and large fibre function was examined with quantitative sensory testing in the median nerve territory of the hand. Vibration and mechanical detection thresholds were significantly elevated in patients with carpal tunnel syndrome (P < 0.007) confirming large fibre dysfunction and patients also presented with increased thermal detection thresholds (P < 0.0001) indicative of C and A?-fibre dysfunction. Mechanical and thermal pain thresholds were comparable between groups (P > 0.13). A skin biopsy was taken from a median nerve innervated area of the proximal phalanx of the index finger. Immunohistochemical staining for protein gene product 9.5 and myelin basic protein was used to evaluate morphological features of unmyelinated and myelinated axons. Evaluation of intraepidermal nerve fibre density showed a striking loss in patients (P < 0.0001) confirming a significant compromise of small fibres. The extent of Meissner corpuscles and dermal nerve bundles were comparable between groups (P > 0.07). However, patients displayed a significant increase in the percentage of elongated nodes (P < 0.0001), with altered architecture of voltage-gated sodium channel distribution. Whereas neither neurophysiology nor quantitative sensory testing correlated with patients’ symptoms or function deficits, the presence of elongated nodes was inversely correlated with a number of functional and symptom related scores (P < 0.023). Our findings suggest that carpal tunnel syndrome does not exclusively affect large fibres but is associated with loss of function in modalities mediated by both unmyelinated and myelinated sensory axons. We also document for the first time that entrapment neuropathies lead to a clear reduction in intraepidermal nerve fibre density, which was independent of electrodiagnostic test severity. The presence of elongated nodes in the target tissue further suggests that entrapment neuropathies affect nodal structure/myelin well beyond the focal compression site. Interestingly, nodal lengthening may be an adaptive phenomenon as it inversely correlates with symptom severity. PMID:25348629

  12. Functional coupling between motor and sensory nerves through contraction of sphincters in the pudendal area of the female cat.

    PubMed

    Lagunes-Córdoba, Roberto; Hernández, Pablo Rogelio; Raya, José Guadalupe; Muńoz-Martínez, E J

    2010-01-01

    The question of whether skin receptors might help in the perception of muscle contraction and body movement has not been settled. The present study gives direct evidence of skin receptor firing in close coincidence with the contraction of the vaginal and anal sphincters. The distal stump of the sectioned motor pudendal nerve was stimulated. Single shocks induced a wavelike increase in the lumen pressure of the distal vagina and the anal canal, as well as constriction of the vaginal introitus and the anus. The constriction pulls on and moves the surrounding skin, which was initially detected visually. In the present experiments, a thin strain gauge that pressed on the skin surface detected its displacement. Single shocks to the motor nerve induced a wave of skin movement with maximal amplitude at 5 mm from the anus and propagated with decrement beyond 35 mm. The peripheral terminals of the sensory pudendal nerve and the posterior femoral nerve supply the skin that moves. Sensory axons from both nerves fired in response to both tactile stimulation and the skin movement produced by the constriction of the orifices (motor-sensory coupling). In cats with all nerves intact, a single shock to the sensory nerves induced reflex waves of skin movement and lumen pressure (sensory-motor coupling). Both couplings provide evidence for a feedforward action that might help to maintain the female posture during mating and to the perception of muscle contraction. PMID:19846621

  13. Peripheral injury of pelvic visceral sensory nerves alters GFR? (GDNF family receptor alpha) localization in sensory and autonomic pathways of the sacral spinal cord

    PubMed Central

    Forrest, Shelley L.; Payne, Sophie C.; Keast, Janet R.; Osborne, Peregrine B.

    2015-01-01

    GDNF (glial cell line-derived neurotrophic factor), neurturin and artemin use their co-receptors (GFR?1, GFR?2 and GFR?3, respectively) and the tyrosine kinase Ret for downstream signaling. In rodent dorsal root ganglia (DRG) most of the unmyelinated and some myelinated sensory afferents express at least one GFR?. The adult function of these receptors is not completely elucidated but their activity after peripheral nerve injury can facilitate peripheral and central axonal regeneration, recovery of sensation, and sensory hypersensitivity that contributes to pain. Our previous immunohistochemical studies of spinal cord and sciatic nerve injuries in adult rodents have identified characteristic changes in GFR?1, GFR?2 or GFR?3 in central spinal cord axons of sensory neurons located in DRG. Here we extend and contrast this analysis by studying injuries of the pelvic and hypogastric nerves that contain the majority of sensory axons projecting to the pelvic viscera (e.g., bladder and lower bowel). At 7 d, we detected some effects of pelvic but not hypogastric nerve transection on the ipsilateral spinal cord. In sacral (L6-S1) cord ipsilateral to nerve injury, GFR?1-immunoreactivity (IR) was increased in medial dorsal horn and CGRP-IR was decreased in lateral dorsal horn. Pelvic nerve injury also upregulated GFR?1- and GFR?3-IR terminals and GFR?1-IR neuronal cell bodies in the sacral parasympathetic nucleus that provides the spinal parasympathetic preganglionic output to the pelvic nerve. This evidence suggests peripheral axotomy has different effects on somatic and visceral sensory input to the spinal cord, and identifies sensory-autonomic interactions as a possible site of post-injury regulation. PMID:25914629

  14. Intervertebral disc, sensory nerves and neurotrophins: who is who in discogenic pain?

    PubMed Central

    García-Cosamalón, José; del Valle, Miguel E; Calavia, Marta G; García-Suárez, Olivia; López-Muńiz, Alfonso; Otero, Jesús; Vega, José A

    2010-01-01

    The normal intervertebral disc (IVD) is a poorly innervated organ supplied only by sensory (mainly nociceptive) and postganglionic sympathetic (vasomotor efferents) nerve fibers. Interestingly, upon degeneration, the IVD becomes densely innervated even in regions that in normal conditions lack innervation. This increased innervation has been associated with pain of IVD origin. The mechanisms responsible for nerve growth and hyperinnervation of pathological IVDs have not been fully elucidated. Among the molecules that are presumably involved in this process are some members of the family of neurotrophins (NTs), which are known to have both neurotrophic and neurotropic properties and regulate the density and distribution of nerve fibers in peripheral tissues. NTs and their receptors are expressed in healthy IVDs but much higher levels have been observed in pathological IVDs, thus suggesting a correlation between levels of expression of NTs and density of innervation in IVDs. In addition, NTs also play a role in inflammatory responses and pain transmission by increasing the expression of pain-related peptides and modulating synapses of nociceptive neurons at the spinal cord. This article reviews current knowledge about the innervation of IVDs, NTs and NT receptors, expression of NTs and their receptors in IVDs as well as in the sensory neurons innervating the IVDs, the proinflammatory role of NTs, NTs as nociception regulators, and the potential network of discogenic pain involving NTs. PMID:20456524

  15. Secretion of Growth Hormone in Response to Muscle Sensory Nerve Stimulation

    NASA Technical Reports Server (NTRS)

    Grindeland, Richard E.; Roy, R. R.; Edgerton, V. R.; Gosselink, K. L.; Grossman, E. J.; Sawchenko, P. E.; Wade, Charles E. (Technical Monitor)

    1994-01-01

    Growth hormone (GH) secretion is stimulated by aerobic and resistive exercise and inhibited by exposure to actual or simulated (bedrest, hindlimb suspension) microgravity. Moreover, hypothalamic growth hormone-releasing factor (GRF) and preproGRF mRNA are markedly decreased in spaceflight rats. These observations suggest that reduced sensory input from inactive muscles may contribute to the reduced secretion of GH seen in "0 G". Thus, the aim of this study was to determine the effect of muscle sensory nerve stimulation on secretion of GH. Fed male Wistar rats (304 +/- 23 g) were anesthetized (pentobarbital) and the right peroneal (Pe), tibial (T), and sural (S) nerves were cut. Electrical stimulation of the distal (D) or proximal (P) ends of the nerves was implemented for 15 min. to mimic the EMG activity patterns of ankle extensor muscles of a rat walking 1.5 mph. The rats were bled by cardiac puncture and their anterior pituitaries collected. Pituitary and plasma bioactive (BGH) and immunoactive (IGH) GH were measured by bioassay and RIA.

  16. Cutaneous sensory nerve as a substitute for auditory nerve in solving deaf-mutes' hearing problem: an innovation in multi-channel-array skin-hearing technology.

    PubMed

    Li, Jianwen; Li, Yan; Zhang, Ming; Ma, Weifang; Ma, Xuezong

    2014-08-15

    The current use of hearing aids and artificial cochleas for deaf-mute individuals depends on their auditory nerve. Skin-hearing technology, a patented system developed by our group, uses a cutaneous sensory nerve to substitute for the auditory nerve to help deaf-mutes to hear sound. This paper introduces a new solution, multi-channel-array skin-hearing technology, to solve the problem of speech discrimination. Based on the filtering principle of hair cells, external voice signals at different frequencies are converted to current signals at corresponding frequencies using electronic multi-channel bandpass filtering technology. Different positions on the skin can be stimulated by the electrode array, allowing the perception and discrimination of external speech signals to be determined by the skin response to the current signals. Through voice frequency analysis, the frequency range of the band-pass filter can also be determined. These findings demonstrate that the sensory nerves in the skin can help to transfer the voice signal and to distinguish the speech signal, suggesting that the skin sensory nerves are good candidates for the replacement of the auditory nerve in addressing deaf-mutes' hearing problems. Scientific hearing experiments can be more safely performed on the skin. Compared with the artificial cochlea, multi-channel-array skin-hearing aids have lower operation risk in use, are cheaper and are more easily popularized. PMID:25317171

  17. Cutaneous sensory nerve as a substitute for auditory nerve in solving deaf-mutes’ hearing problem: an innovation in multi-channel-array skin-hearing technology

    PubMed Central

    Li, Jianwen; Li, Yan; Zhang, Ming; Ma, Weifang; Ma, Xuezong

    2014-01-01

    The current use of hearing aids and artificial cochleas for deaf-mute individuals depends on their auditory nerve. Skin-hearing technology, a patented system developed by our group, uses a cutaneous sensory nerve to substitute for the auditory nerve to help deaf-mutes to hear sound. This paper introduces a new solution, multi-channel-array skin-hearing technology, to solve the problem of speech discrimination. Based on the filtering principle of hair cells, external voice signals at different frequencies are converted to current signals at corresponding frequencies using electronic multi-channel bandpass filtering technology. Different positions on the skin can be stimulated by the electrode array, allowing the perception and discrimination of external speech signals to be determined by the skin response to the current signals. Through voice frequency analysis, the frequency range of the band-pass filter can also be determined. These findings demonstrate that the sensory nerves in the skin can help to transfer the voice signal and to distinguish the speech signal, suggesting that the skin sensory nerves are good candidates for the replacement of the auditory nerve in addressing deaf-mutes’ hearing problems. Scientific hearing experiments can be more safely performed on the skin. Compared with the artificial cochlea, multi-channel-array skin-hearing aids have lower operation risk in use, are cheaper and are more easily popularized. PMID:25317171

  18. Interaction between TRPA1 and TRPV1: Synergy on pulmonary sensory nerves.

    PubMed

    Lee, Lu-Yuan; Hsu, Chun-Chun; Lin, Yu-Jung; Lin, Ruei-Lung; Khosravi, Mehdi

    2015-12-01

    Transient receptor potential ankyrin type 1 (TRPA1) and vanilloid type 1 (TRPV1) receptors are co-expressed in vagal pulmonary C-fiber sensory nerves. Because both these ligand-gated non-selective cation channels are sensitive to a number of endogenous inflammatory mediators, it is highly probable that they can be activated simultaneously during airway inflammation. Studies were carried out to investigate whether there is an interaction between these two polymodal transducers upon simultaneous activation, and how it modulates the activity of vagal pulmonary C-fiber sensory nerves. Our studies showed a distinct potentiating effect induced abruptly by simultaneous activations of TRPA1 and TRPV1 by their respective selective agonists, allyl isothiocyanate (AITC) and capsaicin (Cap), at near-threshold concentrations. This synergistic effect was demonstrated in the studies of single-unit recording of vagal bronchopulmonary C-fiber afferents and the reflex responses elicited by activation of these afferents in intact animals, as well as in the isolated nodose and jugular bronchopulmonary sensory neurons. This potentiating effect was absent when either AITC or Cap was replaced by non-TRPA1 and non-TRPV1 chemical activators of these neurons, demonstrating the selectivity of the interaction between these two TRP channels. Furthermore, the synergism was dependent upon the extracellular Ca(2+), and the rapid onset of the action further suggests that the interaction probably occurred locally at the sites of these channels. These findings suggest that the TRPA1-TRPV1 interaction may play an important role in regulating the function and excitability of pulmonary sensory neurons during airway inflammation, but the mechanism underlying this positive interaction is not yet fully understood. PMID:26283426

  19. Sensory Recovery Outcome after Digital Nerve Repair in Relation to Different Reconstructive Techniques: Meta-Analysis and Systematic Review

    PubMed Central

    Wolf, Petra; Harder, Yves; Kern, Yasmin; Paprottka, Philipp M.; Machens, Hans-Günther; Lohmeyer, Jörn A.

    2013-01-01

    Good clinical outcome after digital nerve repair is highly relevant for proper hand function and has a significant socioeconomic impact. However, level of evidence for competing surgical techniques is low. The aim is to summarize and compare the outcomes of digital nerve repair with different methods (end-to-end and end-to-side coaptations, nerve grafts, artificial conduit-, vein-, muscle, and muscle-in-vein reconstructions, and replantations) to provide an aid for choosing an individual technique of nerve reconstruction and to create reference values of standard repair for nonrandomized clinical studies. 87 publications including 2,997 nerve repairs were suitable for a precise evaluation. For digital nerve repairs there was practically no particular technique superior to another. Only end-to-side coaptation had an inferior two-point discrimination in comparison to end-to-end coaptation or nerve grafting. Furthermore, this meta-analysis showed that youth was associated with an improved sensory recovery outcome in patients who underwent digital replantation. For end-to-end coaptations, recent publications had significantly better sensory recovery outcomes than older ones. Given minor differences in outcome, the main criteria in choosing an adequate surgical technique should be gap length and donor site morbidity caused by graft material harvesting. Our clinical experience was used to provide a decision tree for digital nerve repair. PMID:23984064

  20. Sensory fibres modulate histamine-induced catecholamine secretion from the rat adrenal medulla and sympathetic nerves.

    PubMed Central

    Khalil, Z; Livett, B G; Marley, P D

    1987-01-01

    1. We have studied the mechanism of catecholamine secretion induced by histamine from the adrenal medulla and sympathetic noradrenergic neurones in the rat, and the role of capsaicin-sensitive sensory nerves in this secretion. 2. Histamine at a dose of 1 mg/kg induced adrenaline and noradrenaline secretion by a non-neurogenic mechanism. In contrast, at a dose of 3 mg/kg it induced adrenaline and noradrenaline secretion by both non-neurogenic and neurogenic mechanisms. 3. The adrenaline released in response to histamine at 3 mg/kg was exclusively of adrenal origin whereas the noradrenaline released was of non-adrenal origin (most probably noradrenergic sympathetic nerves). As with its action on the adrenal, histamine induced noradrenaline secretion from these extra-adrenal tissues by both neurogenic and non-neurogenic mechanisms. 4. When adrenaline secretion from the adrenal gland was impaired by adrenal denervation and/or adrenalectomy, the plasma noradrenaline secretion was increased. This is most probably due to compensation from the rest of the sympathetic nervous system. This compensatory increase in noradrenaline was abolished by hexamethonium, which indicates that it was mediated by a cholinergic mechanism. 5. Pre-treatment of rats as neonates subcutaneously with capsaicin (a selective neurotoxin for certain sensory nerves) at a dose of 50 mg/kg, had no effect on the non-neurogenic secretion of catecholamine induced by histamine. In contrast, capsaicin pre-treatment abolished the neurogenic catecholamine secretion in response to histamine as well as the neurogenic compensatory increase in plasma noradrenaline levels that occurred when adrenaline secretion by the adrenal gland was impaired. 6. In the present study, by using histamine as a form of stress, we have been able to provide evidence not only (a) to confirm a role for capsaicin-sensitive sensory fibres in modulating neurogenic adrenaline secretion from the adrenal gland, but also (b) to suggest a similar role for these fibres in modulating neurogenic noradrenaline release from sympathetic noradrenergic nerves in response to histamine and in response to impairment of adrenaline secretion by the adrenal gland. PMID:3443956

  1. Sensory capacity of reinnervated skin after redirection of amputated upper limb nerves to the chest

    PubMed Central

    Schultz, Aimee E.; Kuiken, Todd A.

    2009-01-01

    Targeted reinnervation is a new neural-machine interface that has been developed to help improve the function of new-generation prosthetic limbs. Targeted reinnervation is a surgical procedure that takes the nerves that once innervated a severed limb and redirects them to proximal muscle and skin sites. The sensory afferents of the redirected nerves reinnervate the skin overlying the transfer site. This creates a sensory expression of the missing limb in the amputee's reinnervated skin. When these individuals are touched on this reinnervated skin they feel as though they are being touched on their missing limb. Targeted reinnervation takes nerves that once served the hand, a skin region of high functional importance, and redirects them to less functionally relevant skin areas adjacent to the amputation site. In an effort to better understand the sensory capacity of the reinnervated target skin following this procedure, we examined grating orientation thresholds and point localization thresholds on two amputees who had undergone the targeted reinnervation surgery. Grating orientation thresholds and point localization thresholds were also measured on the contralateral normal skin of the targeted reinnervation amputees and on analogous sites in able-bodied controls. Grating orientation thresholds for the reinnervated skin of the targeted reinnervation amputees were found to be similar to normal ranges for both the amputees’ contralateral skin and also for the control population. Point localization thresholds for these amputees were found to be lower for their reinnervated skin than for their contralateral skin. Reinnervated point localization thresholds values were also lower in comparison to homologous chest sites on the control population. Mechanisms appear to be in place to maximize re-established touch input in targeted reinnervation amputees. It seems that sound sensory function is provided to the denervated skin of the residual limb when connected to afferent pathways once serving highly functionally relevant regions of the brain. This suggests that tactile interface devices could be used to give a physiologically appropriate sense of touch to a prosthetic limb, which would likely help with better functional utilization of the prosthetic device and possibly help to more effectively integrate the device with the user's self-image. PMID:19369486

  2. Self-powered sensory nerve system for civil structures using hybrid forisome actuators

    NASA Astrophysics Data System (ADS)

    Shoureshi, Rahmat A.; Shen, Amy

    2006-03-01

    In order to provide a true distributed sensor and control system for civil structures, we have developed a Structural Nervous System that mimics key attributes of a human nervous system. This nervous system is made up of building blocks that are designed based on mechanoreceptors as a fundamentally new approach for the development of a structural health monitoring and diagnostic system that utilizes the recently discovered plant-protein forisomes, a novel non-living biological material capable of sensing and actuation. In particular, our research has been focused on producing a sensory nervous system for civil structures by using forisomes as the mechanoreceptors, nerve fibers, neuronal pools, and spinocervical tract to the nodal and central processing units. This paper will present up to date results of our research, including the design and analysis of the structural nervous system.

  3. THE MAJORITY OF MYELINATED AND UNMYELINATED SENSORY NERVE FIBERS THAT INNERVATE BONE EXPRESS THE TROPOMYOSIN RECEPTOR KINASE A

    PubMed Central

    Castańeda-Corral, Gabriela; Jimenez-Andrade, Juan M.; Bloom, Aaron P.; Taylor, Reid N.; Mantyh, William G.; Kaczmarska, Magdalena J.; Ghilardi, Joseph R.; Mantyh, Patrick W.

    2011-01-01

    Although skeletal pain is a leading cause of chronic pain and disability, relatively little is known about the specific populations of nerve fibers that innervate the skeleton. Recent studies have reported that therapies blocking nerve growth factor (NGF) or its cognate receptor, tropomyosin receptor kinase A (TrkA) are efficacious in attenuating skeletal pain. A potential factor to consider when assessing the analgesic efficacy of targeting NGF-TrkA signaling in a pain state is the fraction of NGF-responsive TrkA+ nociceptors that innervate the tissue from which the pain is arising, as this innervation and the analgesic efficacy of targeting NGF-TrkA signaling may vary considerably from tissue to tissue. To explore this in the skeleton, tissue slices and whole mount preparations of the normal, adult mouse femur were analyzed using immunohistochemistry and confocal microscopy. Analysis of these preparations revealed that 80% of the unmyelinated/thinly myelinated sensory nerve fibers that express calcitonin gene-related peptide (CGRP) and innervate the periosteum, mineralized bone and bone marrow also express TrkA. Similarly, the majority of myelinated sensory nerve fibers that express neurofilament 200 kDa (NF200) which innervate the periosteum, mineralized bone and bone marrow also co-express TrkA. In the normal femur, the relative density of CGRP+, NF200+ and TrkA+ sensory nerve fibers per unit volume is: periosteum > bone marrow > mineralized bone > cartilage with the respective relative densities being 100: 2: 0.1: 0. The observation that the majority of sensory nerve fibers innervating the skeleton express TrkA+, may in part explain why therapies that block NGF/TrkA pathway are highly efficacious in attenuating skeletal pain. PMID:21277945

  4. Implementation of linear sensory signaling via multiple coordinated mechanisms at central vestibular nerve synapses.

    PubMed

    McElvain, Lauren E; Faulstich, Michael; Jeanne, James M; Moore, Jeffrey D; du Lac, Sascha

    2015-03-01

    Signal transfer in neural circuits is dynamically modified by the recent history of neuronal activity. Short-term plasticity endows synapses with nonlinear transmission properties, yet synapses in sensory and motor circuits are capable of signaling linearly over a wide range of presynaptic firing rates. How do such synapses achieve rate-invariant transmission despite history-dependent nonlinearities? Here, ultrastructural, biophysical, and computational analyses demonstrate that concerted molecular, anatomical, and physiological refinements are required for central vestibular nerve synapses to linearly transmit rate-coded sensory signals. Vestibular synapses operate in a physiological regime of steady-state depression imposed by tonic firing. Rate-invariant transmission relies on brief presynaptic action potentials that delimit calcium influx, large pools of rapidly mobilized vesicles, multiple low-probability release sites, robust postsynaptic receptor sensitivity, and efficient transmitter clearance. Broadband linear synaptic filtering of head motion signals is thus achieved by coordinately tuned synaptic machinery that maintains physiological operation within inherent cell biological limitations. PMID:25704949

  5. Structural preservation of deafferented cortex induced by electrical stimulation of a sensory peripheral nerve.

    PubMed

    Herrera-Rincon, Celia; Torets, Carlos; Sanchez-Jimenez, Abel; Avendańo, Carlos; Guillen, Pedro; Panetsos, Fivos

    2010-01-01

    Any manipulation to natural sensory input has direct effects on the morphology and physiology of the Central Nervous System. In the particular case of amputations, sensory areas of the brain undergo degenerative processes with a marked reduction in neuronal activity and global disinhibition. This is probably due to a deregulation of the circuits devoted to the control of the cortical activity. These changes are detected in the organization of the representational maps, the metabolic labeling by 2-deoxyglucose or cytochrome oxidase, the density of afferent and efferent axonal connections and the reduced expression of inhibitory neurotransmitters. In the present study, performed in animals, we have evaluated the therapeutic potential of Brain Machine Interfaces in reversing or limiting the degenerative/deregulation processes of amputations. Applying electrical stimulation on amputated peripheral nerves, we have achieved to maintain in approximately normal values 1) the cortical activity and 2) the expression of GABA-associated molecules of the inhibitory interneurons of the primary somatosensory cortex. PMID:21096028

  6. Roles of Sensory Nerves in the Regulation of Radiation-Induced Structural and Functional Changes in the Heart

    SciTech Connect

    Sridharan, Vijayalakshmi; Tripathi, Preeti; Sharma, Sunil; Moros, Eduardo G.; Zheng, Junying; Hauer-Jensen, Martin; Boerma, Marjan

    2014-01-01

    Purpose: Radiation-induced heart disease (RIHD) is a chronic severe side effect of radiation therapy of intrathoracic and chest wall tumors. The heart contains a dense network of sensory neurons that not only are involved in monitoring of cardiac events such as ischemia and reperfusion but also play a role in cardiac tissue homeostasis, preconditioning, and repair. The purpose of this study was to examine the role of sensory nerves in RIHD. Methods and Materials: Male Sprague-Dawley rats were administered capsaicin to permanently ablate sensory nerves, 2 weeks before local image-guided heart x-ray irradiation with a single dose of 21 Gy. During the 6 months of follow-up, heart function was assessed with high-resolution echocardiography. At 6 months after irradiation, cardiac structural and molecular changes were examined with histology, immunohistochemistry, and Western blot analysis. Results: Capsaicin pretreatment blunted the effects of radiation on myocardial fibrosis and mast cell infiltration and activity. By contrast, capsaicin pretreatment caused a small but significant reduction in cardiac output 6 months after irradiation. Capsaicin did not alter the effects of radiation on cardiac macrophage number or indicators of autophagy and apoptosis. Conclusions: These results suggest that sensory nerves, although they play a predominantly protective role in radiation-induced cardiac function changes, may eventually enhance radiation-induced myocardial fibrosis and mast cell activity.

  7. The Trichoplax PaxB Gene: A Putative Proto-PaxA/B/C Gene Predating the Origin of Nerve and Sensory Cells

    E-print Network

    DeSalle, Rob

    , beside Porifera the only meta- zoan phylum that completely lacks nerve and sensory cells or organs genes from Cnidaria and Porifera belong to four classes, PaxA­D (Balczarek, Lai, and Kumar 1997; Sun et

  8. Alpha-Synuclein Pathology in Sensory Nerve Terminals of the Upper Aerodigestive Tract of Parkinson’s Disease Patients

    PubMed Central

    Mu, Liancai; Chen, Jingming; Sobotka, Stanislaw; Nyirenda, Themba; Benson, Brian; Gupta, Fiona; Sanders, Ira; Adler, Charles H.; Caviness, John N.; Shill, Holly A.; Sabbagh, Marwan; Samanta, Johan E.; Sue, Lucia I.; Beach, Thomas G.

    2015-01-01

    Dysphagia is common in Parkinson’s disease (PD) and causes significant morbidity and mortality. PD dysphagia has usually been explained as dysfunction of central motor control, much like other motor symptoms that are characteristic of the disease. However, PD dysphagia does not correlate with severity of motor symptoms nor does it respond to motor therapies. It is known that PD patients have sensory deficits in the pharynx, and that impaired sensation may contribute to dysphagia. However, the underlying cause of the pharyngeal sensory deficits in PD is not known. We hypothesized that PD dysphagia with sensory deficits may be due to degeneration of the sensory nerve terminals in the upper aerodigestive tract (UAT). We have previously shown that Lewy-type synucleinopathy (LTS) is present in the main pharyngeal sensory nerves of PD patients, but not in controls. In this study, the sensory terminals in UAT mucosa were studied to discern the presence and distribution of LTS. Whole-mount specimens (tongue-pharynx-larynx-upper esophagus) were obtained from 10 deceased human subjects with clinically diagnosed and neuropathologically confirmed PD (five with dysphagia and five without) and four age-matched healthy controls. Samples were taken from six sites and immunostained for phosphorylated ?-synuclein (PAS). The results showed the presence of PAS-immunoreactive (PAS-ir) axons in all the PD subjects and in none of the controls. Notably, PD patients with dysphagia had more PAS-ir axons in the regions that are critical for initiating the swallowing reflex. These findings suggest that Lewy pathology affects mucosal sensory axons in specific regions of the UAT and may be related to PD dysphagia. PMID:26041249

  9. Sensory recovery after primary repair of palmar digital nerves using a Revolnerv(®) collagen conduit: a prospective series of 27 cases.

    PubMed

    Arnaout, A; Fontaine, C; Chantelot, C

    2014-09-01

    Despite advances in microsurgery, digital nerve repair remains a challenge due to the lack of reproducible procedures with satisfactory functional results. The aim of this study was to compare the sensory and functional results of direct microsurgical sutures protected by a Revolnerv(®) nerve regeneration conduit, with results of a series of direct sutures without a protective conduit in the literature. From November 2009 to April 2010, 35 patients were treated by direct epiperineural suture for digital nerve injury, protected by a Revolnerv(®) nerve regeneration conduit at the FESUM centre "SOS-mains Lesquin/CHRU de Lille". Sensory recovery was assessed by the static two-point discrimination Weber test (WS) and the Semmes-Weinstein (SW) test at postoperative months 1, 3, and 6. The final evaluation was performed after a minimum follow-up of 6 months. Statistical analysis of sensory results (WS and SW) was mainly performed with non-parametric tests (Wilcoxon, Mann and Whitney). P<0.05 was considered to be statistically significant. One patient was excluded, six were lost to follow-up, and four could not be seen at the 6-month follow-up visit. Finally, 24 patients and 27 nerve sutures were included. Mean age was 38 years old and the ratio of women/men was 1/5. Eighty-five percent of the patients had useful (S3+) or normal (S4) discrimination at 6 months, and the average WS was 10.3 (±3.76). There was a tendency to better WS results in sharp transections compared to jagged lacerations (9.19 vs 11.82). The SW test was satisfactory in 15% of patients and acceptable in 30%. There were no complications from the Revolnerv(®) collagen tube. After 6 months follow-up this study shows that results with the Revolnerv(®) nerve regeneration conduit on direct palmar digital nerve sutures were comparable to but not better than those of uncoated direct sutures. A study including a larger population with longer follow-up is necessary to determine the value of this technique and its recommendation for general use in all digital nerve injuries. PMID:25169199

  10. The effect of treatment with BRX-220, a co-inducer of heat shock proteins, on sensory fibers of the rat following peripheral nerve injury

    E-print Network

    Burnstock, Geoffrey

    The effect of treatment with BRX-220, a co-inducer of heat shock proteins, on sensory fibers the effect BRX-220, a co-inducer of heat shock proteins, in injury-induced peripheral neuropathy. Following sciatic nerve injury in adult rats and treatment with BRX-220, the following features of the sensory

  11. Differential myelinated and unmyelinated sensory and autonomic skin nerve fiber involvement in patients with ophthalmic postherpetic neuralgia

    PubMed Central

    Truini, Andrea; Haanpaa, Maija; Provitera, Vincenzo; Biasiotta, Antonella; Stancanelli, Annamaria; Caporaso, Giuseppe; Santoro, Lucio; Cruccu, Giorgio; Nolano, Maria

    2015-01-01

    Postherpetic neuralgia (PHN) is a common and exceptionally drug-resistant neuropathic pain condition. In this cross-sectional skin biopsy study, seeking information on the responsible pathophysiological mechanisms we assessed how ophthalmic PHN affects sensory and autonomic skin innervation. We took 2-mm supraorbital punch skin biopsies from the affected and unaffected sides in 10 patients with ophthalmic PHN. Using indirect immunofluorescence and a large panel of antibodies including protein gene product (PGP) 9.5 we quantified epidermal unmyelinated, dermal myelinated and autonomic nerve fibers. Although skin biopsy showed reduced epidermal and dermal myelinated fiber density in specimens from the affected side, the epidermal/dermal myelinated nerve fiber ratio was lower in the affected than in the unaffected side (p < 0.001), thus suggesting a predominant epidermal unmyelinated nerve fiber loss. Conversely, autonomic skin innervation was spared. Our study showing that ophthalmic PHN predominantly affects unmyelinated nerve fiber and spares autonomic nerve fiber might help to understand the pathophysiological mechanisms underlying this difficult-to-treat condition. PMID:26300742

  12. N-glycosylation determines ionic permeability and desensitization of the TRPV1 capsaicin receptor.

    PubMed

    Veldhuis, Nicholas A; Lew, Michael J; Abogadie, Fe C; Poole, Daniel P; Jennings, Ernest A; Ivanusic, Jason J; Eilers, Helge; Bunnett, Nigel W; McIntyre, Peter

    2012-06-22

    The balance of glycosylation and deglycosylation of ion channels can markedly influence their function and regulation. However, the functional importance of glycosylation of the TRPV1 receptor, a key sensor of pain-sensing nerves, is not well understood, and whether TRPV1 is glycosylated in neurons is unclear. We report that TRPV1 is N-glycosylated and that N-glycosylation is a major determinant of capsaicin-evoked desensitization and ionic permeability. Both N-glycosylated and unglycosylated TRPV1 was detected in extracts of peripheral sensory nerves by Western blotting. TRPV1 expressed in HEK-293 cells exhibited various degrees of glycosylation. A mutant of asparagine 604 (N604T) was not glycosylated but did not alter plasma membrane expression of TRPV1. Capsaicin-evoked increases in intracellular calcium ([Ca(2+)](i)) were sustained in wild-type TRPV1 HEK-293 cells but were rapidly desensitized in N604T TRPV1 cells. There was marked cell-to-cell variability in capsaicin responses and desensitization between individual cells expressing wild-type TRPV1 but highly uniform responses in cells expressing N604T TRPV1, consistent with variable levels of glycosylation of the wild-type channel. These differences were also apparent when wild-type or N604T TRPV1-GFP fusion proteins were expressed in neurons from trpv1(-/-) mice. Capsaicin evoked a marked, concentration-dependent increase in uptake of the large cationic dye YO-PRO-1 in cells expressing wild-type TRPV1, indicative of loss of ion selectivity, that was completely absent in cells expressing N604T TRPV1. Thus, TRPV1 is variably N-glycosylated and glycosylation is a key determinant of capsaicin regulation of TRPV1 desensitization and permeability. Our findings suggest that physiological or pathological alterations in TRPV1 glycosylation would affect TRPV1 function and pain transmission. PMID:22570472

  13. Sensory nerves contribute to cutaneous vasodilator response to cathodal stimulation in healthy rats.

    PubMed

    Gohin, Stéphanie; Decorps, Johanna; Sigaudo-Roussel, Dominique; Fromy, Bérengčre

    2015-09-01

    Cutaneous current-induced vasodilation (CIV) in response to galvanic current application is an integrative model of neurovascular interaction that relies on capsaicin-sensitive fiber activation. The upstream and downstream mechanisms related to the activation of the capsaicin-sensitive fibers involved in CIV are not elucidated. In particular, the activation of cutaneous transient receptor potential vanilloid type-1 (TRPV1) channels and/or acid-sensing ion channels (ASIC) (activators mechanisms) and the release of calcitonin gene-related peptide (CGRP) and substance P (SP) (effector mechanisms) have been tested. To assess cathodal CIV, we measured cutaneous blood flow using laser Doppler flowmetry for 20min following cathodal current application (240s, 100?A) on the skin of the thigh in anesthetized healthy rats for 20min. CIV was studied in rats treated with capsazepine and amiloride to inhibit TRPV1 and ASIC channels, respectively; CGRP8-37 and SR140333 to antagonize CGRP and neurokinin-1 (NK1) receptors, respectively; compared to their respective controls. Cathodal CIV was attenuated by capsazepine (12±2% vs 54±6%, P<0.001), amiloride (19±8% vs 61±6%, P<0.01), CGRP8-37 (15±6% vs 61±6%, P<0.001) and SR140333 (9±5% vs 54±6%, P<0.001) without changing local acidification. This is the first integrative study performed in healthy rats showing that cutaneous vasodilation in response to cathodal stimulation is initiated by activation of cutaneous TRPV1 and ASIC channels likely through local acidification. The involvement of CGRP and NK1 receptors suggests that cathodal CIV is the result of CGRP and SP released through activated capsaicin-sensitive fibers. Therefore cathodal CIV could be a valuable method to assess sensory neurovascular function in the skin, which would be particularly relevant to evaluate the presence of small nerve fiber disorders and the effectiveness of treatments. PMID:26205659

  14. Capsaicin-sensitive sensory nerves exert complex regulatory functions in the serum-transfer mouse model of autoimmune arthritis

    PubMed Central

    Borbély, Éva; Botz, Bálint; Bölcskei, Kata; Kenyér, Tibor; Kereskai, László; Kiss, Tamás; Szolcsányi, János; Pintér, Erika; Csepregi, Janka Zsófia; Mócsai, Attila; Helyes, Zsuzsanna

    2015-01-01

    Objective The K/BxN serum-transfer arthritis is a widely-used translational mouse model of rheumatoid arthritis, in which the immunological components have thoroughly been investigated. In contrast, little is known about the role of sensory neural factors and the complexity of neuro–immune interactions. Therefore, we analyzed the involvement of capsaicin-sensitive peptidergic sensory nerves in autoantibody-induced arthritis with integrative methodology. Methods Arthritogenic K/BxN or control serum was injected to non-pretreated mice or resiniferatoxin (RTX)-pretreated animals where capsaicin-sensitive nerves were inactivated. Edema, touch sensitivity, noxious heat threshold, joint function, body weight and clinical arthritis severity scores were determined repeatedly throughout two weeks. Micro-CT and in vivo optical imaging to determine matrix-metalloproteinase (MMP) and neutrophil-derived myeloperoxidase (MPO) activities, semiquantitative histopathological scoring and radioimmunoassay to measure somatostatin in the joint homogenates were also performed. Results In RTX-pretreated mice, the autoantibody-induced joint swelling, arthritis severity score, MMP and MPO activities, as well as histopathological alterations were significantly greater compared to non-pretreated animals. Self-control quantification of the bone mass revealed decreased values in intact female mice, but significantly greater arthritis-induced pathological bone formation after RTX-pretreatment. In contrast, mechanical hyperalgesia from day 10 was smaller after inactivating capsaicin-sensitive afferents. Although thermal hyperalgesia did not develop, noxious heat threshold was significantly higher following RTX pretreatment. Somatostatin-like immunoreactivity elevated in the tibiotarsal joints in non-pretreated, which was significantly less in RTX-pretreated mice. Conclusions Although capsaicin-sensitive sensory nerves mediate mechanical hyperalgesia in the later phase of autoantibody-induced chronic arthritis, they play important anti-inflammatory roles at least partially through somatostatin release. PMID:25524130

  15. End-to-side neurorrhaphy for defects of palmar sensory digital nerves.

    PubMed

    Voche, P; Ouattara, D

    2005-03-01

    Ten traumatic nerve defects at the palm or digit level were treated by end-to-side (ETS) neurorrhaphy. The technique included removal of an epineurial window on the donor nerve and coaptation of the sharply cut distal end of the injured nerve by epineurial stitches under microscopic magnification. At final follow-up, the static two-point discrimination test (2 pd) scored at an average of 9.1 mm (range, 6-12 mm) on the repaired nerve, compared to an average of 4.6 mm (range, 4-6 mm) on the contralateral uninjured control side. Moving 2 pd scored at an average of 7 mm (range, 4-9 mm) on the repaired nerve compared to an average of 2.6 mm (range, 2-4 mm) on the control side. This short series showed that ETS neurorrhaphies are effective and give comparable results with those of nerve grafts or vein conduits. PMID:15710121

  16. Quantitative assessment of the ability of collateral sprouting of the motor and primary sensory neurons after the end-to-side neurorrhaphy of the rat musculocutaneous nerve with the ulnar nerve.

    PubMed

    Sámal, Filip; Haninec, Pavel; Raska, Otakar; Dubov?, Petr

    2006-07-01

    In view of the Lack of theoretical information, end-to-side neurorrhaphy is a frequent object of experimental interest. End-to-side neurorrhaphy is based on collateral sprouting of an intact axon. The quantitative assessment of collateral sprouts sent by an intact motor and sensory axon was the goal of the present study. End-to-side neurorrhaphy of the distal stump of transected musculocutaneous nerve (MCN) with intact ulnar nerve (UN) was performed in a rat model. Collateral sprouts were quantitatively evaluated by counting of motoneurons and DRG neurons following their retrograde labeling by Fluoro-Ruby and Fluoro-Emerald applied to the UN and MCN, respectively. The results suggest a comparable capacity of both intact sensory and motor axons to send collateral sprouts into a denervated nerve stump. The ratio of sensory/motor neurons, the axons of which reinnervated distal MCN stumps, was very similar to that of intact UN (6.500 and 6.747, respectively), but different from intact MCN (5.029). This suggests that the pruning process occurred to balance the collateral sprouts at a ratio of sensory/motor neurons for the donor UN, but not according to the number of sensory and motor bands of Bungner available in the distal stump of the MCN. The present experimental study confirms end-to-side neurorrhaphy as a suitable method of nerve reconstruction. PMID:16856598

  17. Early nerve repair after injury to the postganglionic plexus: an experimental study of sensory and motor neuronal survival in adult rats.

    PubMed

    Ma, Jianjun; Novikov, Lev N; Kellerth, Jan-Olof; Wiberg, Mikael

    2003-01-01

    The optimal time for brachial plexus nerve repair is debatable. In this study we examined whether early re-establishment of neurotrophic support from the periphery might reduce neuronal loss. In 14 adult rats, the C7 spinal nerve was transsected. All sensory cells of the dorsal root ganglion and spinal motor neurons projecting into the C7 nerve were labelled retrogradely. The proximal and distal portions of the C7 nerve were then reanastomosed by either primary repair or by a vascularised or conventional ulnar nerve graft. At 16 weeks postoperatively, the nerve repair had significantly reduced the loss of both sensory and motor C7 neurons. Most striking was that a 30% motor neuronal loss in the control was almost eliminated by early nerve repair. In the grafted animals, half of the surviving neurons had regenerated through the graft, with no difference between vascularised and conventional nerve grafts. These results suggest that early surgical intervention may promote neuronal survival and regeneration after injuries to the brachial plexus. PMID:12625387

  18. Different Effects of Implanting Sensory Nerve or Blood Vessel on the Vascularization, Neurotization, and Osteogenesis of Tissue-Engineered Bone In Vivo

    PubMed Central

    Fan, Jun-jun; Mu, Tian-wang; Qin, Jun-jun; Bi, Long; Pei, Guo-xian

    2014-01-01

    To compare the different effects of implanting sensory nerve tracts or blood vessel on the osteogenesis, vascularization, and neurotization of the tissue-engineered bone in vivo, we constructed the tissue engineered bone and implanted the sensory nerve tracts (group SN), blood vessel (group VB), or nothing (group Blank) to the side channel of the bone graft to repair the femur defect in the rabbit. Better osteogenesis was observed in groups SN and VB than in group Blank, and no significant difference was found between groups SN and VB at 4, 8, and 12 weeks postoperatively. The neuropeptides expression and the number of new blood vessels in the bone tissues were increased at 8 weeks and then decreased at 12 weeks in all groups and were highest in group VB and lowest in group Blank at all three time points. We conclude that implanting either blood vessel or sensory nerve tract into the tissue-engineered bone can significantly enhance both the vascularization and neurotization simultaneously to get a better osteogenesis effect than TEB alone, and the method of implanting blood vessel has a little better effect of vascularization and neurotization but almost the same osteogenesis effect as implanting sensory nerve. PMID:25101279

  19. Lactic acid-induced plasma protein extravasation in rat airways by stimulation of sensory nerves and NK1 receptor activation.

    PubMed

    Auberson, S; Lundberg, J M

    1993-12-01

    Locally applied lactic acid and capsaicin caused extravasation of Evans blue dye in trachea, main bronchi and nasal mucosa of anaesthetized rats. In animals pretreated with capsaicin to deplete sensory neuropeptides, the lactic acid response was abolished in main bronchi and highly reduced in trachea. Pretreatment with the NK1 receptor antagonist, RP 67580 (3 mg x kg-1 intravenously), markedly inhibited the lactic acid-induced extravasation at all levels; similar pretreatment with NK2 receptor antagonist, SR 48968 (0.5 mg x kg-1 intravenously), was ineffective. Locally applied ruthenium red (a transmembrane Ca2+ fluxes inhibitor), capsazepine (a capsacin receptor antagonist) and diclofenac intraperitoneally (a cyclooxygenase blocker) did not change the lactic acid effect, while the capsaicin response was only diminished in bronchi by local pretreatment with ruthenium red. In conclusion locally applied lactic acid in rat trachea and nasal cavity activated capsaicin sensitive sensory nerve endings producing plasma protein extravasation. This reaction was shown to be mediated by tachykinins acting on the NK1 receptor through a mechanism which appeared to be resistant to capsazepine and ruthenium red and independent of cyclooxygenase products. In comparison the effect of capsacin was partially ruthenium red-sensitive but not influenced by capsazepine. PMID:8153052

  20. Peripheral nerve regeneration and NGF-dependent neurite outgrowth of adult sensory neurons converge on STAT3 phosphorylation downstream of neuropoietic cytokine receptor gp130.

    PubMed

    Quarta, Serena; Baeumer, Bastian E; Scherbakov, Nadja; Andratsch, Manfred; Rose-John, Stefan; Dechant, Georg; Bandtlow, Christine E; Kress, Michaela

    2014-09-24

    After nerve injury, adult sensory neurons can regenerate peripheral axons and reconnect with their target tissue. Initiation of outgrowth, as well as elongation of neurites over long distances, depends on the signaling of receptors for neurotrophic growth factors. Here, we investigated the importance of gp130, the signaling subunit of neuropoietic cytokine receptors in peripheral nerve regeneration. After sciatic nerve crush, functional recovery in vivo was retarded in SNS-gp130(-/-) mice, which specifically lack gp130 in sensory neurons. Correspondingly, a significantly reduced number of free nerve endings was detected in glabrous skin from SNS-gp130(-/-) compared with control mice after nerve crush. Neurite outgrowth and STAT3 activation in vitro were severely reduced in cultures in gp130-deficient cultured neurons. Surprisingly, in neurons obtained from SNS-gp130(-/-) mice the increase in neurite length was reduced not only in response to neuropoietic cytokine ligands of gp130 but also to nerve growth factor (NGF), which does not bind to gp130-containing receptors. Neurite outgrowth in the absence of neurotrophic factors was partially rescued in gp130-deficient neurons by leptin, which activates STAT3 downstream of leptic receptor and independent of gp130. The neurite outgrowth response of gp130-deficient neurons to NGF was fully restored in the presence of leptin. Based on these findings, gp130 signaling via STAT3 activation is suggested not only to be an important regulator of peripheral nerve regeneration in vitro and in vivo, but as determining factor for the growth promoting action of NGF in adult sensory neurons. PMID:25253866

  1. Characterization of Thoracic Motor and Sensory Neurons and Spinal Nerve Roots in Canine Degenerative Myelopathy, a Potential Disease Model of Amyotrophic Lateral Sclerosis

    PubMed Central

    Morgan, Brandie R.; Coates, Joan R.; Johnson, Gayle C.; Shelton, G. Diane; Katz, Martin L.

    2014-01-01

    Canine Degenerative Myelopathy (DM) is a progressive adult-onset multisystem degenerative disease with many features in common with amyotrophic lateral sclerosis (ALS). As with some forms of ALS, DM is associated with mutations in superoxide dismutase 1 (SOD1). Clinical signs include general proprioceptive ataxia and spastic upper motor neuron paresis in pelvic limbs, which progress to flaccid tetraplegia and dysphagia. The purpose of this study was to characterize DM as a potential disease model for ALS. We previously reported that intercostal muscle atrophy develops in dogs with advanced stage DM. To determine if other components of the thoracic motor unit (MU) also demonstrated morphological changes consistent with dysfunction, histopathologic and morphometric analyses were conducted on thoracic spinal motor neurons (MN) and dorsal root ganglia (DRG), and in motor and sensory nerve root axons from DM-affected Boxers and Pembroke Welsh Corgis (PWCs). No alterations in MNs, or motor root axons were observed in either breed. However, advanced stage PWCs exhibited significant losses of sensory root axons, and numerous DRG sensory neurons displayed evidence of degeneration. These results indicate that intercostal muscle atrophy in DM is not preceded by physical loss of the motor neurons innervating these muscles, or of their axons. Axonal loss in thoracic sensory roots and sensory nerve death suggest sensory involvement may play an important role in DM disease progression. Further analysis of the mechanisms responsible for these morphological findings would aid in the development of therapeutic intervention for DM and some forms of ALS. PMID:24375814

  2. The impact and specificity of nerve perturbation on novel vibrotactile sensory letter learning.

    PubMed

    Passmore, Steven R; Bosse, Jessica; Murphy, Bernadette; Lee, Timothy D

    2014-12-01

    The purposes of this study were to determine if induced radiating paresthesia interferes with (a) acquisition and/or (b) utilization of complex tactile information, and (c) identify whether interference reflects tactile masking or response competition. Radiating ulnar (experiment 1) and median (experiment 2) nerve paresthesia was quantified on ulnar innervated vibrotactile Morse code letter acquisition and recollection tasks. Induced paresthesia differentially impacted letter acquisition and recollection, but only when presented to the same anatomical spatial location. PMID:24844345

  3. Regulating cough through modulation of sensory nerve function in the airways.

    PubMed

    Spina, D; Page, C P

    2013-10-01

    Whilst local anaesthetics when applied directly to laryngeal nerves or topically to the lung can suppress cough, their chronic use is constrained because of dose limiting side effects. However, the effectiveness of local anaesthetics suggests that selectivity targeting nerves in the airway may provide novel approaches for the treatment of cough in the future. There is a considerable wealth of evidence showing that there are different afferent nerve subtypes in the airways. Traditionally C-fibres have been the focus of much research in the cough field since the stimulation of these afferents by capsaicin is able to elicit cough in guinea-pigs and in man, and drugs targeting various proteins expressed in these nerves (e.g. mu-opioid, NOP1, TRPV1, sodium channels) have been shown to be anti-tussive in preclinical models of cough. However, interest in A? fibres has increased recently in light of the discovery of a specific cough receptor in the guinea-pig that is provoked by citric acid and punctate stimulation, but not capsaicin and which has been anatomically linked to A? fibres. There is also some evidence that as a result of inflammation in the airways, A? fibres can begin to express neuropeptides and TRPV1 receptors so that they can become responsive to endogenous activators of this ion channel and to irritants like capsaicin. Consequently, there is considerable interest in targeting either one or both afferent nerve types for the treatment of chronic cough. However, to date the translation of preclinical studies into man has largely been disappointing and certainly there is a need for better preclinical models in this field. There also remain many challenges to overcome at a clinical level, such as what patient group(s) should be used to assess anti-tussive drugs and whether the use of irritants that induce cough in healthy volunteers (such as citric acid or capsaicin) is of any value in the assessment of novel anti-tussive drugs. The development of several continuous monitoring methodologies for measuring cough will hopefully allow better evaluation of treatments in patients with chronic cough. Nonetheless, cough remains a major unmet clinical need in respiratory medicine where new drugs are urgently required. PMID:23524012

  4. Substitution of natural sensory input by artificial neurostimulation of an amputated trigeminal nerve does not prevent the degeneration of basal forebrain cholinergic circuits projecting to the somatosensory cortex

    PubMed Central

    Herrera-Rincon, Celia; Panetsos, Fivos

    2014-01-01

    Peripheral deafferentation downregulates acetylcholine (ACh) synthesis in sensory cortices. However, the responsible neural circuits and processes are not known. We irreversibly transected the rat infraorbital nerve and implanted neuroprosthetic microdevices for proximal stump stimulation, and assessed cytochrome-oxidase and choline- acetyl-transferase (ChAT) in somatosensory, auditory and visual cortices; estimated the number and density of ACh-neurons in the magnocellular basal nucleus (MBN); and localized down-regulated ACh-neurons in basal forebrain using retrograde labeling from deafferented cortices. Here we show that nerve transection, causes down regulation of MBN cholinergic neurons. Stimulation of the cut nerve reverses the metabolic decline but does not affect the decrease in cholinergic fibers in cortex or cholinergic neurons in basal forebrain. Artifical stimulation of the nerve also has no affect of ACh-innervation of other cortices. Cortical ChAT depletion is due to loss of corticopetal MBN ChAT-expressing neurons. MBN ChAT downregulation is not due to a decrease of afferent activity or to a failure of trophic support. Basalocortical ACh circuits are sensory specific, ACh is provided to each sensory cortex “on demand” by dedicated circuits. Our data support the existence of a modality-specific cortex-MBN-cortex circuit for cognitive information processing. PMID:25452715

  5. Substitution of natural sensory input by artificial neurostimulation of an amputated trigeminal nerve does not prevent the degeneration of basal forebrain cholinergic circuits projecting to the somatosensory cortex.

    PubMed

    Herrera-Rincon, Celia; Panetsos, Fivos

    2014-01-01

    Peripheral deafferentation downregulates acetylcholine (ACh) synthesis in sensory cortices. However, the responsible neural circuits and processes are not known. We irreversibly transected the rat infraorbital nerve and implanted neuroprosthetic microdevices for proximal stump stimulation, and assessed cytochrome-oxidase and choline- acetyl-transferase (ChAT) in somatosensory, auditory and visual cortices; estimated the number and density of ACh-neurons in the magnocellular basal nucleus (MBN); and localized down-regulated ACh-neurons in basal forebrain using retrograde labeling from deafferented cortices. Here we show that nerve transection, causes down regulation of MBN cholinergic neurons. Stimulation of the cut nerve reverses the metabolic decline but does not affect the decrease in cholinergic fibers in cortex or cholinergic neurons in basal forebrain. Artifical stimulation of the nerve also has no affect of ACh-innervation of other cortices. Cortical ChAT depletion is due to loss of corticopetal MBN ChAT-expressing neurons. MBN ChAT downregulation is not due to a decrease of afferent activity or to a failure of trophic support. Basalocortical ACh circuits are sensory specific, ACh is provided to each sensory cortex "on demand" by dedicated circuits. Our data support the existence of a modality-specific cortex-MBN-cortex circuit for cognitive information processing. PMID:25452715

  6. Co-localization of the vanilloid capsaicin receptor and substance P in sensory nerve fibers innervating cochlear and vertebro-basilar arteries.

    PubMed

    Vass, Z; Dai, C F; Steyger, P S; Jancsó, G; Trune, D R; Nuttall, A L

    2004-01-01

    Evidence suggests that capsaicin-sensitive substance P (SP)-containing trigeminal ganglion neurons innervate the spiral modiolar artery (SMA), radiating arterioles, and the stria vascularis of the cochlea. Antidromic electrical or chemical stimulation of trigeminal sensory nerves results in neurogenic plasma extravasation in inner ear tissues. The primary aim of this study was to reveal the possible morphological basis of cochlear vascular changes mediated by capsaicin-sensitive sensory nerves. Therefore, the distribution of SP and capsaicin receptor (transient receptor potential vanilloid type 1-TRPV1) was investigated by double immunolabeling to demonstrate the anatomical relationships between the cochlear and vertebro-basilar blood vessels and the trigeminal sensory fiber system. Extensive TRPV1 and SP expression and co-localization were observed in axons within the adventitial layer of the basilar artery, the anterior inferior cerebellar artery, the SMA, and the radiating arterioles of the cochlea. There appears to be a functional relationship between the trigeminal ganglion and the cochlear blood vessels since electrical stimulation of the trigeminal ganglion induced significant plasma extravasation from the SMA and the radiating arterioles. The findings suggest that stimulation of paravascular afferent nerves may result in permeability changes in the basilar and cochlear vascular bed and may contribute to the mechanisms of vertebro-basilar type of headache through the release of SP and stimulation of TPVR1, respectively. We propose that vertigo, tinnitus, and hearing deficits associated with migraine may arise from perturbations of capsaicin-sensitive trigeminal sensory ganglion neurons projecting to the cochlea. PMID:15026132

  7. CO-LOCALIZATION OF THE VANILLOID CAPSAICIN RECEPTOR AND SUBSTANCE P IN SENSORY NERVE FIBERS INNERVATING COCHLEAR AND VERTEBRO-BASILAR ARTERIES

    PubMed Central

    VASS, Z.; DAI, C. F.; STEYGER, P. S.; JANCSÓ, G.; TRUNE, D. R.; NUTTALL, A. L.

    2014-01-01

    Evidence suggests that capsaicin-sensitive substance P (SP)-containing trigeminal ganglion neurons innervate the spiral modiolar artery (SMA), radiating arterioles, and the stria vascularis of the cochlea. Antidromic electrical or chemical stimulation of trigeminal sensory nerves results in neurogenic plasma extravasation in inner ear tissues. The primary aim of this study was to reveal the possible morphological basis of cochlear vascular changes mediated by capsaicin-sensitive sensory nerves. Therefore, the distribution of SP and capsaicin receptor (transient receptor potential vanilloid type 1—TRPV1) was investigated by double immunolabeling to demonstrate the anatomical relationships between the cochlear and vertebro-basilar blood vessels and the trigeminal sensory fiber system. Extensive TRPV1 and SP expression and co-localization were observed in axons within the adventitial layer of the basilar artery, the anterior inferior cerebellar artery, the SMA, and the radiating arterioles of the cochlea. There appears to be a functional relationship between the trigeminal ganglion and the cochlear blood vessels since electrical stimulation of the trigeminal ganglion induced significant plasma extravasation from the SMA and the radiating arterioles. The findings suggest that stimulation of paravascular afferent nerves may result in permeability changes in the basilar and cochlear vascular bed and may contribute to the mechanisms of vertebro-basilar type of headache through the release of SP and stimulation of TPVR1, respectively. We propose that vertigo, tinnitus, and hearing deficits associated with migraine may arise from perturbations of capsaicin-sensitive trigeminal sensory ganglion neurons projecting to the cochlea. PMID:15026132

  8. Endogenous Prostaglandins and Afferent Sensory Nerves in Gastroprotective Effect of Hydrogen Sulfide against Stress-Induced Gastric Lesions

    PubMed Central

    Magierowski, Marcin; Jasnos, Katarzyna; Kwiecien, Slawomir; Drozdowicz, Danuta; Surmiak, Marcin; Strzalka, Malgorzata; Ptak-Belowska, Agata; Wallace, John L.; Brzozowski, Tomasz

    2015-01-01

    Hydrogen sulfide (H2S) plays an important role in human physiology, exerting vasodilatory, neuromodulatory and anti-inflammatory effects. H2S has been implicated in the mechanism of gastrointestinal integrity but whether this gaseous mediator can affect hemorrhagic lesions induced by stress has been little elucidated. We studied the effect of the H2S precursor L-cysteine, H2S-donor NaHS, the H2S synthesizing enzyme (CSE) activity inhibitor- D,L-propargylglycine (PAG) and the gastric H2S production by CSE/CBS/3-MST activity in water immersion and restraint stress (WRS) ulcerogenesis and the accompanying changes in gastric blood flow (GBF). The role of endogenous prostaglandins (PGs) and sensory afferent nerves releasing calcitonin gene-related peptide (CGRP) in the mechanism of gastroprotection induced by H2S was examined in capsaicin-denervated rats and those pretreated with capsazepine to inhibit activity of vanilloid receptors (VR-1). Rats were pretreated with vehicle, NaHS, the donor of H2S and or L-cysteine, the H2S precursor, with or without the concurrent treatment with 1) nonselective (indomethacin) and selective cyclooxygenase (COX)-1 (SC-560) or COX-2 (rofecoxib) inhibitors. The expression of mRNA and protein for COX-1 and COX-2 were analyzed in gastric mucosa pretreated with NaHS with or without PAG. Both NaHS and L-cysteine dose-dependently attenuated severity of WRS-induced gastric lesions and significantly increased GBF. These effects were significantly reduced by pretreatment with PAG and capsaicin denervation. NaHS increased gastric H2S production via CSE/CBS but not 3-MST activity. Inhibition of COX-1 and COX-2 activity significantly diminished NaHS- and L-cysteine-induced protection and hyperemia. NaHS increased expression of COX-1, COX-2 mRNAs and proteins and raised CGRP mRNA expression. These effects of NaHS on COX-1 and COX-2 protein contents were reversed by PAG and capsaicin denervation. We conclude that H2S exerts gastroprotection against WRS-induced gastric lesions by the mechanism involving enhancement in gastric microcirculation mediated by endogenous PGs, sensory afferent nerves releasing CGRP and the activation of VR-1 receptors. PMID:25774496

  9. Endogenous prostaglandins and afferent sensory nerves in gastroprotective effect of hydrogen sulfide against stress-induced gastric lesions.

    PubMed

    Magierowski, Marcin; Jasnos, Katarzyna; Kwiecien, Slawomir; Drozdowicz, Danuta; Surmiak, Marcin; Strzalka, Malgorzata; Ptak-Belowska, Agata; Wallace, John L; Brzozowski, Tomasz

    2015-01-01

    Hydrogen sulfide (H2S) plays an important role in human physiology, exerting vasodilatory, neuromodulatory and anti-inflammatory effects. H2S has been implicated in the mechanism of gastrointestinal integrity but whether this gaseous mediator can affect hemorrhagic lesions induced by stress has been little elucidated. We studied the effect of the H2S precursor L-cysteine, H2S-donor NaHS, the H2S synthesizing enzyme (CSE) activity inhibitor- D,L-propargylglycine (PAG) and the gastric H2S production by CSE/CBS/3-MST activity in water immersion and restraint stress (WRS) ulcerogenesis and the accompanying changes in gastric blood flow (GBF). The role of endogenous prostaglandins (PGs) and sensory afferent nerves releasing calcitonin gene-related peptide (CGRP) in the mechanism of gastroprotection induced by H2S was examined in capsaicin-denervated rats and those pretreated with capsazepine to inhibit activity of vanilloid receptors (VR-1). Rats were pretreated with vehicle, NaHS, the donor of H2S and or L-cysteine, the H2S precursor, with or without the concurrent treatment with 1) nonselective (indomethacin) and selective cyclooxygenase (COX)-1 (SC-560) or COX-2 (rofecoxib) inhibitors. The expression of mRNA and protein for COX-1 and COX-2 were analyzed in gastric mucosa pretreated with NaHS with or without PAG. Both NaHS and L-cysteine dose-dependently attenuated severity of WRS-induced gastric lesions and significantly increased GBF. These effects were significantly reduced by pretreatment with PAG and capsaicin denervation. NaHS increased gastric H2S production via CSE/CBS but not 3-MST activity. Inhibition of COX-1 and COX-2 activity significantly diminished NaHS- and L-cysteine-induced protection and hyperemia. NaHS increased expression of COX-1, COX-2 mRNAs and proteins and raised CGRP mRNA expression. These effects of NaHS on COX-1 and COX-2 protein contents were reversed by PAG and capsaicin denervation. We conclude that H2S exerts gastroprotection against WRS-induced gastric lesions by the mechanism involving enhancement in gastric microcirculation mediated by endogenous PGs, sensory afferent nerves releasing CGRP and the activation of VR-1 receptors. PMID:25774496

  10. Use of nerve conduction studies and the pressure-specified sensory device in the diagnosis of carpal tunnel syndrome.

    PubMed

    Slutsky, D J

    2009-02-01

    Sixty-nine patients with signs of carpal tunnel syndrome (CTS) underwent nerve conduction studies (NCS) and testing with the Pressure-Specified Sensory Device (PSSD). A total of 102 tests were performed (28 bilateral). Twenty patients underwent a carpal tunnel release and were retested after 4 to 6 months. The Symptom Severity Score (SSS) was calculated before and after surgery. A control group of 20 hands in 10 asymptomatic volunteers underwent identical testing. The NCS sensitivity was 87% with a specificity of 90% whereas the PSSD sensitivity was 81% with a specificity of 65%. The combined sensitivity of the two tests was 93%. In the operative group the SSS improved from a mean of 3.34 pre-operatively to 1.95 postoperatively. The NCS improved in 19/21 hands whereas the PSSD improved in 16/19 hands. The non-invasive SSS and PSSD can increase the diagnostic yield in CTS, especially when the NCS are normal. PMID:19129354

  11. Overexpression of nerve growth factor by murine smooth muscle cells: role of the p75 neurotrophin receptor on sympathetic and sensory sprouting.

    PubMed

    Petrie, Casey N; Smithson, Laura J; Crotty, Anne-Marie; Michalski, Bernadeta; Fahnestock, Margaret; Kawaja, Michael D

    2013-08-01

    Elevating levels of nerve growth factor (NGF) can have pronounced effects on the survival and maintenance of distinct populations of neurons. We have generated a line of transgenic mice in which NGF is expressed under the control of the smooth muscle ?-actin promoter. These transgenic mice have augmented levels of NGF protein in the descending colon and urinary bladder, so these tissues display increased densities of NGF-sensitive sympathetic efferents and sensory afferents. Here we provide a thorough examination of sympathetic and sensory axonal densities in the descending colon and urinary bladder of NGF transgenic mice with and without the expression of the p75 neurotrophin receptor (p75NTR). In response to elevated NGF levels, sympathetic axons (immunostained for tyrosine hydroxylase) undergo robust collateral sprouting in the descending colon and urinary bladder of adult transgenic mice (i.e., those tissues having smooth muscle cells); this sprouting is not augmented in the absence of p75NTR expression. As for sensory axons (immunostained for calcitonin gene-related peptide) in the urinary bladders of transgenic mice, fibers undergo sprouting that is further increased in the absence of p75NTR expression. Sympathetic axons are also seen invading the sensory ganglia of transgenic mice; these fibers form perineuronal plexi around a subpopulation of sensory somata. Our results reveal that elevated levels of NGF in target tissues stimulate sympathetic and sensory axonal sprouting and that an absence of p75NTR by sensory afferents (but not by sympathetic efferents) leads to a further increase of terminal arborization in certain NGF-rich peripheral tissues. PMID:23322532

  12. An ultrastructural study of the relationship between sensory trigeminal nerves and odontoblasts in rat dentin/pulp as demonstrated by the anterograde transport of wheat germ agglutinin-horseradish peroxidase (WGA-HRP).

    PubMed

    Ibuki, T; Kido, M A; Kiyoshima, T; Terada, Y; Tanaka, T

    1996-12-01

    Because the ultrastructure of the trigeminal sensory nerves in dentin, especially in relation to odontoblasts, remains to be clarified, we investigated the relationship between the trigeminal sensory nerves and the odontoblast processes using the anterograde axonal transport technique by injecting wheat germ agglutinin-horseradish peroxidase (WGA-HRP) into the rat trigeminal ganglion. Light microscopically, the nerves labeled with WGA-HRP were mainly concentrated at the pulpal horn, forming a nerve plexus at the subodontoblastic region and penetrating the predentin/dentin about 50 to 70 microns. Ultrastructurally, HRP reaction products were observed intra-axonally in the myelinated (A delta) and unmyelinated (C) axons in the subodontoblastic region. Most nerves lost the Schwann sheath and were naked in the predentin/dentin. The labeled varicosities were close to the odontoblast processes in the dentinal tubules. No synaptic structures could be detected between the varicosities and the odontoblasts, but a gap about 20 nm wide was found between them. One type of varicosity was a rich mitochondria-containing varicosity, while the other was a rich vesicle-containing (large dense core vesicles and small clear vesicles) one. The reaction products were also found in the extracellular spaces surrounding the axons. Sometimes the reaction products were seen in the coated pits or the endocytotic vesicles of the odontoblast processes. The present study demonstrated that nerve endings (varicosities) derived from the trigeminal ganglion were present in the dentinal tubules, and that WGA-HRP extracellularly extruded from the sensory nerves in the odontoblastic layer or predentin/dentin. These findings thus suggest that sensory nerves may have some (e.g., trophic) effect on either odontoblasts or the environment around the sensory nerves in the dentin/pulp. PMID:9033451

  13. Stimuli of Sensory-Motor Nerves Terminate Arterial Contractile Effects of Endothelin-1 by CGRP and Dissociation of ET-1/ETA-Receptor Complexes

    PubMed Central

    Meens, Merlijn J. P. M. T.; Compeer, Matthijs G.; Hackeng, Tilman M.; van Zandvoort, Marc A.; Janssen, Ben J. A.; De Mey, Jo G. R.

    2010-01-01

    Background Endothelin-1 (ET-1), a long-acting paracrine mediator, is implicated in cardiovascular diseases but clinical trials with ET-receptor antagonists were not successful in some areas. We tested whether the quasi-irreversible receptor-binding of ET-1 (i) limits reversing effects of the antagonists and (ii) can be selectively dissociated by an endogenous counterbalancing mechanism. Methodology/Principal findings In isolated rat mesenteric resistance arteries, ETA-antagonists, endothelium-derived relaxing factors and synthetic vasodilators transiently reduced contractile effects of ET-1 but did not prevent persistent effects of the peptide. Stimuli of peri-vascular vasodilator sensory-motor nerves such as capsaicin not only reduced but also terminated long-lasting effects of ET-1. This was prevented by CGRP-receptor antagonists and was mimicked by exogenous calcitonin gene-related peptide (CGRP). Using 2-photon laser scanning microscopy in vital intact arteries, capsaicin and CGRP, but not ETA-antagonism, were observed to promote dissociation of pre-existing ET-1/ETA-receptor complexes. Conclusions Irreversible binding and activation of ETA-receptors by ET-1 (i) occur at an antagonist-insensitive site of the receptor and (ii) are selectively terminated by endogenously released CGRP. Hence, natural stimuli of sensory-motor nerves that stimulate release of endogenous CGRP can be considered for therapy of diseases involving ET-1. PMID:20532232

  14. Nerve growth factor mediates a switch in intracellular signaling for PGE2-induced sensitization of sensory neurons from protein kinase A to Epac.

    PubMed

    Vasko, Michael R; Habashy Malty, Ramy; Guo, Chunlu; Duarte, Djane B; Zhang, Yihong; Nicol, Grant D

    2014-01-01

    We examined whether nerve growth factor (NGF), an inflammatory mediator that contributes to chronic hypersensitivity, alters the intracellular signaling that mediates the sensitizing actions of PGE2 from activation of protein kinase A (PKA) to exchange proteins directly activated by cAMP (Epacs). When isolated sensory neurons are grown in the absence of added NGF, but not in cultures grown with 30 ng/ml NGF, inhibiting protein kinase A (PKA) activity blocks the ability of PGE2 to augment capsaicin-evoked release of the neuropeptide CGRP and to increase the number of action potentials (APs) evoked by a ramp of current. Growing sensory neurons in culture in the presence of increasing concentrations of NGF increases the expression of Epac2, but not Epac1. An intradermal injection of complete Freund's adjuvant into the rat hindpaw also increases the expression of Epac2, but not Epac1 in the dorsal root ganglia and spinal cord: an effect blocked by intraplantar administration of NGF antibodies. Treating cultures grown in the presence of 30 ng/ml NGF with Epac1siRNA significantly reduced the expression of Epac1, but not Epac2, and did not block the ability of PGE2 to augment capsaicin-evoked release of CGRP from sensory neurons. Exposing neuronal cultures grown in NGF to Epac2siRNAreduced the expression of Epac2, but not Epac1 and prevented the PGE2-induced augmentation of capsaicin and potassium-evoked CGRP release in sensory neurons and the PGE2-induced increase in the number of APs generated by a ramp of current. In neurons grown with no added NGF, Epac siRNAs did not attenuate PGE2-induced sensitization. These results demonstrate that NGF, through increasing Epac2 expression, alters the signaling cascade that mediates PGE2-induced sensitization of sensory neurons, thus providing a novel mechanism for maintaining PGE2-induced hypersensitivity during inflammation. PMID:25126967

  15. Different effects of blocked potassium channels on action potentials, accommodation, adaptation and anode break excitation in human motor and sensory myelinated nerve fibres: computer simulations.

    PubMed

    Stephanova, D I; Mileva, K

    2000-08-01

    Action potentials and electrotonic responses to 300-ms depolarizing and hyperpolarizing currents for human motor and sensory myelinated nerve fibres have been simulated on the basis of double cable models. The effects of blocked nodal or internodal potassium (fast or slow) channels on the fibre action potentials, early and late adaptations to 30-ms suprathreshold slowly increasing depolarizing stimuli have been examined. The effects of the same channels on accommodation after the termination of a prolonged (100 ms) hyperpolarizing current pulse have also been investigated. By removing the nodal fast potassium conductance the action potentials of the sensory fibres are considerably broader than those of the motor neurons. For both types of fibres, the blocked nodal slow potassium channels have a substantially smaller effect on the action potential repolarization. When the suprathreshold depolarizing current intensity is increased, the onset of the spike burst occurs sooner, which is common in the behaviour of the fibres. The most striking differences in the burst activity during early adaptation have been found between the fibres when the nodal fist potassium channels are blocked. The results obtained confirm the fact that the motor fibres adapt more quickly to sustained depolarizing current pulses than the sensory ones. The results also show that normal human motor and sensory fibres cannot be excited by a 100-ms hyperpolarizing current pulse, even at the threshold level. When removing the potassium channels in the nodal or internodal axolemma, the posthyperpolarization increase in excitability is small, which is common in the behaviour of the fibres. However, anode break excitation can be simulated in the fibres with simultaneous removal of the potassium channels under the myelin sheath, and this is more pronounced in the human sensory fibres than in motor fibres. This phenomenon can also be found when the internodal and some of the nodal (fast or slow) potassium channels are simultaneously blocked. PMID:10966055

  16. Evidence for the role of lipid rafts and sphingomyelin in Ca(2+)-gating of Transient Receptor Potential channels in trigeminal sensory neurons and peripheral nerve terminals.

    PubMed

    Sághy, Éva; Sz?ke, Éva; Payrits, Maja; Helyes, Zsuzsanna; Börzsei, Rita; Erostyák, János; Jánosi, Tibor Zoltán; Sétáló, György; Szolcsányi, János

    2015-10-01

    Transient Receptor Potential (TRP) cation channels, such as TRP Vanilloid 1 and TRP Ankyrin repeat domain 1 (TRPV1 and TRPA1) are nocisensors playing important role to signal pain. Two "melastatin" TRP receptors, like TRPM8 and TRPM3 are also expressed in a subgroup of primary sensory neurons. These channels serve as thermosensors with unique thermal sensitivity ranges and are activated also by several exogenous and endogenous chemical ligands inducing conformational changes from various allosteric ("multisteric") sites. We analysed the role of plasma membrane microdomains of lipid rafts on isolated trigeminal (TRG) neurons and TRPV1-expressing CHO cell line by measuring agonist-induced Ca(2+) transients with ratiometric technique. Stimulation-evoked calcitonin gene related peptide (CGRP) release from sensory nerve endings of the isolated rat trachea by radioimmunoassay was also measured. Lipid rafts were disrupted by cleaving sphingomyelin (SM) with sphingomyelinase (SMase), cholesterol depletion with methyl ?-cyclodextrin (MCD) and ganglioside breakdown with myriocin. It has been revealed that intracellular Ca(2+) increase responses evoked by the TRPV1 agonist capsaicin, the TRPA1 agonsits allyl isothiocyanate (AITC) and formaldehyde as well as the TRPM8 activator icilin were inhibited after SMase, MCD and myriocin incubation but the response to the TRPM3 agonist pregnenolon sulphate was not altered. Extracellular SMase treatment did not influence the thapsigargin-evoked Ca(2+)-release from intracellular stores. Besides the cell bodies, SMase also inhibited capsaicin- or AITC-evoked CGRP release from peripheral sensory nerve terminals, this provides the first evidence for the importance of lipid raft integrity in TRPV1 and TRPA1 gating on capsaicin-sensitive nerve terminals. SM metabolites, ceramide and sphingosine, did not influence TRPA1 and TRPV1 activation on TRG neurons, TRPV1-expressing CHO cell line, and nerve terminals. We suggest, that the hydrophobic interactions between TRP receptors and membrane lipid raft interfaces modulate the opening properties of these channels and therefore, targeting this interaction might be a promising tool for drug developmental purposes. PMID:26238178

  17. Effect of surgical and chemical sensory denervation on non-neural expression of the transient receptor potential vanilloid 1 (TRPV1) receptors in the rat.

    PubMed

    Kun, József; Helyes, Zsuzsanna; Perkecz, Anikó; Bán, Ágnes; Polgár, Beáta; Szolcsányi, János; Pintér, Erika

    2012-11-01

    Pretreatment with the ultrapotent capsaicin analog resiniferatoxin (RTX) has been applied as a selective pharmacological tool in inflammation and pain studies to desensitize transient receptor potential vanilloid 1 (TRPV1) receptor-expressing sensory nerve endings. The discovery of TRPV1 receptor on non-neural cells challenges systemic RTX desensitization as a method acting exclusively on a population of sensory neurons, but not on non-neural cells. Systemic RTX desensitization was used for chemical denervation and transection of the sciatic and saphenous nerves for surgical denervation in rats. Quantitative real-time PCR and immunohistochemistry were applied to investigate the presence and alterations of the TRPV1 receptor mRNA and protein following chemical and surgical denervation. We provided the first evidence for non-neural TRPV1 immunopositivity and mRNA expression in the rat dorsal paw and plantar skin as well as the oral mucosa. Neither chemical nor surgical denervation influenced the level of TRPV1 receptor mRNA and protein expression in non-neural cells of either skin regions or mucosa. Therefore, RTX and consequently capsaicin remain to be considered as selective neurotoxins for a population of primary afferent neurons. PMID:22528458

  18. Valproic acid hypersensitivity and desensitization.

    PubMed

    Toker, Ori; Tal, Yuval; Horev, Liran; Shmoeli, Dorit; Gilboa, Tal

    2015-11-01

    Rash, a hypersensitivity reaction, is a common cause of withdrawal from an effective antiepileptic drug (AED) in patients with epilepsy. We present a case of successful desensitization to valproic acid in a 12-year-old male with childhood absence epilepsy and a hypersensitivity reaction, whose epilepsy did not respond to other AEDs. Desensitization is a practical therapeutic solution for patients who develop a non-life-threatening hypersensitivity reaction to an AED for which there may be no substitute. PMID:26096509

  19. Dysregulation of the Descending Pain System in Temporomandibular Disorders Revealed by Low-Frequency Sensory Transcutaneous Electrical Nerve Stimulation: A Pupillometric Study

    PubMed Central

    Monaco, Annalisa; Cattaneo, Ruggero; Mesin, Luca; Ortu, Eleonora; Giannoni, Mario; Pietropaoli, Davide

    2015-01-01

    Using computerized pupillometry, our previous research established that the autonomic nervous system (ANS) is dysregulated in patients suffering from temporomandibular disorders (TMDs), suggesting a potential role for ANS dysfunction in pain modulation and the etiology of TMD. However, pain modulation hypotheses for TMD are still lacking. The periaqueductal gray (PAG) is involved in the descending modulation of defensive behavior and pain through ?, ?, and ? opioid receptors. Transcutaneous electrical nerve stimulation (TENS) has been extensively used for pain relief, as low-frequency stimulation can activate µ receptors. Our aim was to use pupillometry to evaluate the effect of low-frequency TENS stimulation of ? receptors on opioid descending pathways in TMD patients. In accordance with the Research Diagnostic Criteria for TMD, 18 females with myogenous TMD and 18 matched-controls were enrolled. All subjects underwent subsequent pupillometric evaluations under dark and light conditions before, soon after (end of stimulation) and long after (recovery period) sensorial TENS. The overall statistics derived from the darkness condition revealed no significant differences in pupil size between cases and controls; indeed, TENS stimulation significantly reduced pupil size in both groups. Controls, but not TMD patients, displayed significant differences in pupil size before compared with after TENS. Under light conditions, TMD patients presented a smaller pupil size compared with controls; the pupil size was reduced only in the controls. Pupil size differences were found before and during TENS and before and after TENS in the controls only. Pupillometry revealed that stimulating the descending opioid pathway with low-frequency sensory TENS of the fifth and seventh pairs of cranial nerves affects the peripheral target. The TMD patients exhibited a different pattern of response to TENS stimulation compared with the controls, suggesting that impaired modulation of the descending pain system may be involved in TMD. PMID:25905862

  20. Anatomical relations of the superficial sensory branches of the radial nerve: a cadaveric study with clinical implications

    PubMed Central

    2011-01-01

    Background Anatomically, it is difficult to give a systematic description of the superficial branch of the radial nerve (SBRN). Our aim was to describe the exact relationship of the SBRN to fixed bony points of radial styloid and Lister's tubercle, and to the cephalic vein. We also compared our data with other international studies. Methods The study was a descriptive anatomical study. Twenty-five forearms were dissected. Measurements were made from predefined fixed reference points. Results The mean distance to the point of emergence of the nerve from the radial styloid was 8.54 cm (SD = 1.32). The nerve branched at a mean distance of 5.57 cm (SD = 1.43) from the radial styloid. The mean distance to the point where the most medial and most lateral branches of the nerve crossing the wrist joint, measured from the Lister's tubercle were 2.51 cm (SD = 0.53) and 3.90 cm (SD = 0.64). In 17 specimens(68%) cephalic vein crossed the SBRN superficially once. Mean distance from the radial styloid to the most distal point where the vein crossed the nerve was 5.10 cm. Diffefrence between mean distance to the point of emergence and branching point, when compared with other international studies were not statistically significant. (P value > 0.05) Conclusions We recommend avoiding transverse incisions in the snuffbox region between 2.51 cm and 3.90 cm from the Listers tubercle. We also recommend avoiding cannulation of the cephalic vein in the distal forearm. PMID:22054296

  1. Changes of cutaneous sensory thresholds induced by non-painful transcutaneous electrical nerve stimulation in normal subjects and in subjects with chronic pain.

    PubMed Central

    Zoppi, M; Francini, F; Maresca, M; Procacci, P

    1981-01-01

    Transcutaneous electrical nerve stimulation (TENS) of the nervi cutaneus surae medialis was applied to 59 healthy subjects and 30 patients suffering from chronic myofascial pain in one lower limb, with an intensity of current that induced a well tolerated tingling sensation. Each period of stimulation lasted 24 minutes. The thresholds of the tactile, tingling and painful sensations were tested at fixed intervals before, during and after stimulation. Trains of constant current square waves in the distribution area of the stimulated nerve (local thresholds) and in other areas (general thresholds) were used. In all subjects repeated changes of the current were necessary in order to maintain constant tingling during the first period of TENS (changing phase); after that few if any changes of the current were necessary (steady phase). There were changes in thresholds within the territory of the electrically stimulated nerve, and marked changes elsewhere and generally in the body. In healthy subjects local thresholds increased during both phases of TENS; general thresholds decreased during the changing phase and increased during the steady phase. After TENS, thresholds showed the same trend as during the steady phase. Trends of the sensory thresholds during and after TENS differed in different subjects according to their thresholds before TENS. Thresholds did not return to normal for more than 20 minutes after TENS. In the group of 30 patients there was a significant difference between thresholds on the two sides of the body. The difference between the two sides was reduced by TENS. Pain relief induced by TENS may be related to this fact. PMID:6975355

  2. Nerve growth factor-induced synapse-like structures in contralateral sensory ganglia contribute to chronic mirror-image pain.

    PubMed

    Cheng, Chau-Fu; Cheng, Jen-Kun; Chen, Chih-Yang; Rau, Ruey-Horng; Chang, Yu-Cheng; Tsaur, Meei-Ling

    2015-11-01

    Elevated nerve growth factor (NGF) in the contralateral dorsal root ganglion (DRG) mediates mirror-image pain after peripheral nerve injury, but the underlying mechanism remains unclear. Using intrathecal injection of NGF antibodies, we found that NGF is required for the development of intra-DRG synapse-like structures made by neurite sprouts of calcitonin gene-related peptide (CGRP) nociceptors and sympathetic axons onto neurite sprouts of Kv4.3 nociceptors. These synapse-like structures are formed near NGF-releasing satellite glia surrounding large DRG neurons. Downregulation of the postsynaptic protein PSD95 with a specific shRNA largely eliminates these synapse-like structures, suppresses activities of Kv4.3 but not CGRP nociceptors, and attenuates mirror-image pain. Furthermore, neutralizing the neurotransmitter norepinephrine or CGRP in the synapse-like structures by antibodies has similar analgesic effect. Thus, elevated NGF after peripheral nerve injury induces neurite sprouting and the formation of synapse-like structures within the contralateral DRG, leading to the development of chronic mirror-image pain. PMID:26121254

  3. Desensitization of metastable intermolecular composites

    DOEpatents

    Busse, James R. (South Fork, CO); Dye, Robert C. (Los Alamos, NM); Foley, Timothy J. (Los Alamos, NM); Higa, Kelvin T. (Ridgecrest, CA); Jorgensen, Betty S. (Jemez Springs, NM); Sanders, Victor E. (White Rock, NM); Son, Steven F. (Los Alamos, NM)

    2011-04-26

    A method to substantially desensitize a metastable intermolecular composite material to electrostatic discharge and friction comprising mixing the composite material with an organic diluent and removing enough organic diluent from the mixture to form a mixture with a substantially putty-like consistency, as well as a concomitant method of recovering the metastable intermolecular composite material.

  4. Distal leg epidermal nerve fiber density as a surrogate marker of HIV-associated sensory neuropathy risk: risk factors and change following initial antiretroviral therapy.

    PubMed

    Shikuma, Cecilia M; Bennett, Kara; Ananworanich, Jintanat; Gerschenson, Mariana; Teeratakulpisarn, Nipat; Jadwattanakul, Tanate; DeGruttola, Victor; McArthur, Justin C; Ebenezer, Gigi; Chomchey, Nitiya; Praihirunkit, Pairoa; Hongchookiat, Piranun; Mathajittiphun, Pornpen; Nakamoto, Beau; Hauer, Peter; Phanuphak, Praphan; Phanuphak, Nittaya

    2015-10-01

    Distal leg epidermal nerve fiber density (ENFD) is a validated predictor of HIV sensory neuropathy (SN) risk. We assessed how ENFD is impacted by initiation of first-time antiretroviral therapy (ART) in subjects free of neuropathy and how it is altered when mitochondrial toxic nucleoside medications are used as part of ART. Serial changes in proximal thigh and distal leg ENFD were examined over 72 weeks in 150 Thai subjects randomized to a regimen of stavudine (d4T) switching to zidovudine (ZDV) at 24 weeks vs ZDV vs tenofovir (TDF) for the entire duration of study, all given in combination with nevirapine. We found individual variations in ENFD change, with almost equal number of subjects who decreased or increased their distal leg ENFD over 72 weeks and no relationship to nucleoside backbone or to development of neuropathic signs or symptoms. Lower baseline distal leg ENFD and greater increases in mitochondrial oxidative phosphorylation complex I (CI) activity were associated with larger increases in distal leg ENFD over 72 weeks. Distal leg ENFD correlated with body composition parameters (body surface area, body mass index, height) as well as with blood pressure measurements. Assessed together with a companion cross-sectional study, we found that mean distal leg ENFD in all HIV+ subjects was lower than in HIV- subjects but similar among HIV+ groups whether ART-naďve or on d4T with/without neuropathy/neuropathic symptoms. The utility of ENFD as a useful predictor of small unmyelinated nerve fiber damage and neuropathy risk in HIV may be limited in certain populations. PMID:26002840

  5. New satiety hormone nesfatin-1 protects gastric mucosa against stress-induced injury: mechanistic roles of prostaglandins, nitric oxide, sensory nerves and vanilloid receptors.

    PubMed

    Szlachcic, Alexandra; Sliwowski, Zbigniew; Krzysiek-Maczka, Gracjana; Majka, Jolanta; Surmiak, Marcin; Pajdo, Robert; Drozdowicz, Danuta; Konturek, Stanislaw J; Brzozowski, Tomasz

    2013-11-01

    Nesfatin-1 belongs to a family of anorexigenic peptides, which are responsible for satiety and are identified in the neurons and endocrine cells within the gut. These peptides have been implicated in the control of food intake; however, very little is known concerning its contribution to gastric secretion and gastric mucosal integrity. In this study the effects of nesfatin-1 on gastric secretion and gastric lesions induced in rats by 3.5h of water immersion and restraint stress (WRS) were determined. Exogenous nesfatin-1 (5-40?g/kg i.p.) significantly decreased gastric acid secretion and attenuated gastric lesions induced by WRS, and this was accompanied by a significant rise in plasma NUCB2/nefatin-1 levels, the gastric mucosal blood flow (GBF), luminal NO concentration, generation of PGE2 in the gastric mucosa, an overexpression of mRNA for NUBC2 and cNOS, as well as a suppression of iNOS and proinflammatory cytokine IL-1? and TNF-? mRNAs. Nesfatin-1-induced protection was attenuated by suppression of COX-1 and COX-2 activity, the inhibition of NOS with L-NNA, the deactivation of afferent nerves with neurotoxic doses of capsaicin, and the pretreatment with capsazepine to inhibit vanilloid VR1 receptors. This study shows for the first time that nesfatin-1 exerts a potent protective action in the stomach of rats exposed to WRS and these effects depend upon decrease in gastric secretion, hyperemia mediated by COX-PG and NOS-NO systems, the activation of vagal and sensory nerves and vanilloid receptors. PMID:23978788

  6. Nerve growth factor-evoked nociceptor sensitization in pig skin in vivo.

    PubMed

    Rukwied, Roman; Schley, Marcus; Forsch, Elmar; Obreja, Otilia; Dusch, Martin; Schmelz, Martin

    2010-07-01

    Peripheral sensitization of skin nociceptors by nerve growth factor (NGF) was explored in pig skin in vivo. As an objective output measure, the area of axon-reflex-mediated erythema was assessed upon mechanical, thermal, chemical, and electrical stimuli delivered at 1, 3, and 7 days after i.d. injection of 1 microg NGF into the pig's back skin (n = 8). Pretreatment with NGF provoked a sensitization to mechanical (600 mN), thermal (10 sec 49 degrees C) and chemical (15 microl, pH 3) stimuli that lasted for 7 days. No sensitization, however, was found in response to weak mechanical (100 mN), weak thermal (10 sec 45 degrees C), or electrical stimuli. Irrespective of the skin pretreatment (NGF or PBS vehicle control), the area of electrically induced erythema decreased upon repetition (days 1-7) by 70% (P < 0.05). Sensitization of sensory endings by NGF upon mechanical, heat, and chemical stimuli suggests recruitment of sensory transducer molecules [e.g., TRPV1, acid-sensing ion channels (ASICs)]. In contrast, the gradual decrease in electrically induced erythema over 7 days might be attributable to axonal desensitization and possibly activity-dependent down-regulation of sodium channels. Thus, long-lasting sensitization processes of nociceptor endings or axonal sodium channel desensitization mechanisms can be explored in the pig as a translational experimental animal model. PMID:20143422

  7. Investigations on neurotoxicity of chemical substances at the workplace. V. Determination of the motor and sensory nerve conduction velocity in persons occupationally exposed to lead.

    PubMed

    Triebig, G; Weltle, D; Valentin, H

    1984-01-01

    A cross-sectional study was performed in order to investigate the influence of chronic lead-exposure on the peripheral nervous system. We examined 148 male workers of a storage battery manufacturing plant, who had been exposed to lead metal and inorganic lead compounds for 1 to 28 years (mean 11 years). Fifteen workers with non-occupational risks of peripheral neuropathy (former diseases, alcohol abuse, medication) were excluded from the study. The investigation program comprised: case history, physical examination, analyses of blood- and urine-samples and determination of maximal motor, mixed and sensory conduction velocity (NCV) of the ulnar and median nerve of the right forearm. Objectively no worker showed any signs of health effects related to lead exposure. The "Biological Monitoring" included the determination of (1) Blood-lead level (Pb-B), (2) Free erythrocyte porphyrins (FEP), (3) delta-Aminolevulinic acid dehydratase (ALA-D) and (4) delta-Aminolevulinic acid in urine (ALA-U). Further "time-weighted-average (TWA)"-values of Pb-B were calculated on the basis of several determinations over the period 1975-1981. The following "actual" ("TWA") median values resulted: Pb-B 53 micrograms/dl (54 micrograms/dl), ALA-U 5.6 mg/l (8.4 mg/l), FEP 2.0 mg/l (2.0 mg/l). The "Biologischer Arbeitsstoff Toleranz Wert (BAT)" of 70 micrograms/dl for Pb-B was exceeded in 15 workers (11%), and of 15 mg/l for ALA-U in 30 cases (23%). In comparison with age-matched controls, the lead workers showed a mild slowing of NCV with mean values between 0.8 and 2.0 m/s. Multiple stepwise regression analyses revealed statistically significant correlations between the four NCV and age as well as Pb-B. There were better correlations by using "TWA" than "actual" data of Pb-B. Consideration of the results of the regression analyses, together with an evaluation of the individual neurophysiological status as a function of internal lead exposure, a "dose-effect-relationship" was found only in the case of Pb-B exceeding 70 micrograms/dl. From our study it is concluded that chronic lead exposure resulting in blood-lead levels of below 70 micrograms/dl is no occupational risk causing a functionally significant slowing of nerve conduction velocities. PMID:6323322

  8. End-to-side neurorrhaphies of the ulnar and median nerves at the wrist: report of two cases without sensory or motor improvement.

    PubMed

    Kayikçio?lu, A; Karamürsel, S; A?ao?lu, G; Keçik, A; Celiker, R; Cetin, A

    2000-12-01

    The authors present two unsuccessful clinical cases of end-to-side neurorrhaphy. In the first patient the distal median nerve was coapted in an end-to-side manner to the intact ulnar nerve. In the other patient four cables of sural nerve graft were used to bridge the ulnar nerve and the intact median nerve by two end-to-side coaptations. Neurorrhaphies were performed via epineural sutures through epineural windows. Both of the cases failed to demonstrate any signs of regeneration either clinically or as evidenced by electromyography, Semmes-Weinstein monofilament test, or 256-Hz vibration tests at 18 and 21 months' follow-up respectively. PMID:11128764

  9. Endogenous Opiate System and Systematic Desensitization.

    ERIC Educational Resources Information Center

    Egan, Kelly J.; And Others

    1988-01-01

    Administered intravenous infusions to phobic patients prior to systematic desensitization. Saline-infused subjects significantly demonstrated the predicted symptom decrease in response to systematic desensitization, whereas naloxone-infused subjects showed no change. Subject reports and psychophysiological measures of arousal indicated no…

  10. Shock desensitizing of solid explosives

    SciTech Connect

    Davis, William C

    2010-01-01

    Solid explosive can be desensitized by a shockwave too weak to initiate it promptly, and desensitized explosive does not react although its chemical composition is almost unchanged. A strong second shock does not cause reaction until it overtakes the first shock. The first shock, if it is strong enough, accelerates very slowly at first, and then more rapidly as detonation approaches. These facts suggest that there are two competing reactions. One is the usual explosive goes to products with the release of energy, and the other is explosive goes to dead explosive with no chemical change and no energy release. The first reaction rate is very sensitive to the local state, and the second is only weakly so. At low pressure very little energy is released and the change to dead explosive dominates. At high pressure, quite the other way, most of the explosive goes to products. Numerous experiments in both the initiation and the full detonation regimes are discussed and compared in support of these ideas.

  11. Shock desensitizing of solid explosive

    SciTech Connect

    Davis, William C

    2010-01-01

    Solid explosive can be desensitized by a shock wave too weak to initiate it promptly, and desensitized explosive does not react although its chemical composition is almost unchanged. A strong second shock does not cause reaction until it overtakes the first shock. The first shock, if it is strong enough, accelerates very slowly at first, and then more rapidly as detonation approaches. These facts suggest that there are two competing reactions. One is the usual explosive goes to products with the release of energy, and the other is explosive goes to dead explosive with no chemical change and no energy release. The first reaction rate is very sensitive to the local state, and the second is only weakly so. At low pressure very little energy is released and the change to dead explosive dominates. At high pressure, quite the other way, most of the explosive goes to products. Numerous experiments in both the initiation and the full detonation regimes are discussed and compared in testing these ideas.

  12. Induction of a reactive state in perineuronal satellite glial cells akin to that produced by nerve injury is linked to the level of p75NTR expression in adult sensory neurons.

    PubMed

    Nadeau, Joelle R; Wilson-Gerwing, Tracy D; Verge, Valerie M K

    2014-05-01

    Satellite glial cells (SGCs) surrounding primary sensory neurons are similar to astrocytes of the central nervous system in that they buffer the extracellular environment via potassium and calcium channels and express the intermediate filament glial fibrillary acidic protein (GFAP). Peripheral nerve injury induces a reactive state in SGCs that includes SGC proliferation, increased SGC/SGC coupling via gap junctions, decreased inward rectifying potassium channel 4.1 (Kir 4.1) expression and increased expression of GFAP and the common neurotrophin receptor, p75NTR. In contrast, neuronal p75NTR expression, normally detected in ?80% of adult rat sensory neurons, decreases in response to peripheral axotomy. Given the differential regulation of p75NTR expression in neurons versus SGCs with injury, we hypothesized that reduced signaling via neuronal p75NTR contributes to the induction of a reactive state in SGCs. We found that reducing neuronal p75NTR protein expression in uninjured sensory neurons by intrathecal subarachnoid infusion of p75NTR-selective anti-sense oligodeoxynucleotides for one week was sufficient to induce a "reactive-like" state in the perineuronal SGCs akin to that normally observed following peripheral nerve injury. This reactive state included significantly increased SGC p75NTR, GFAP and gap junction protein connexin-43 protein expression, increased numbers of SGCs surrounding individual sensory neurons and decreased SGC Kir 4.1 channel expression. Collectively, this supports the tenet that reductions in target-derived trophic support leading to, or as a consequence of, reduced neuronal p75NTR expression plays a critical role in switching the SGC to a reactive state. PMID:24616056

  13. Evaluation of the nerve-injured patient.

    PubMed

    Novak, Christine B

    2003-04-01

    The evaluation of patients with nerve injury or nerve compression requires an accurate history and subjective report to determine the tests that are the most useful in providing the essential information. Motor and sensory evaluation is necessary inglobal mixed-nerve injuries, but in cases of nerve compression, tests of provocation give more accurate information for detecting the site of nerve compression. There is no gold standard test in the evaluation of patients with nerve injury or compression; therefore, a battery of valid and reliable sensory and motor tests provides the most complete information to formulate a treatment plan. PMID:12737348

  14. [Etoposide desensitization. A case report].

    PubMed

    Alvarez Cardona, Aristóteles; Hernández Nieto, Leticia; Pérez Gómez, Martín; Pedroza Meléndez, Alvaro; Huerta López, José G

    2010-01-01

    All chemotherapeutic agents have the potential to induce hypersensitivity reactions and the repeated administration of such drugs during a cancer treatment enhances specific sensitization. Epipodophyllotoxins (etoposide and teniposide) are commonly used to treat lung, testicular, central nervous system and hematologic cancers. Hypersensitivity reactions to epipodophyllotoxins are not the most common but they have been reported. We present a case of an eight-year-old male patient, diagnosed with high risk acute lymphoblastic leukemia who received treatment with etoposide among other drugs (St. Jude XIIIB). During the first course of treatment he needed premedication to etoposide administration because of mild hypersensitivity reactions. At the beginning of a second treatment the patient presented two severe hypersensitivity reactions (acute urticaria, angioedema and hypotension) despite the use of premedication and slow infusion. We initiated a twelve steps desensitization protocol for etoposide with success in the second round allowing the administration of further doses in an ambulatory unit without hypersensitivity reactions. PMID:20857627

  15. Morphological studies of the vestibular nerve

    NASA Technical Reports Server (NTRS)

    Bergstroem, B.

    1973-01-01

    The anatomy of the intratemporal part of the vestibular nerve in man, and the possible age related degenerative changes in the nerve were studied. The form and structure of the vestibular ganglion was studied with the light microscope. A numerical analysis of the vestibular nerve, and caliber spectra of the myelinated fibers in the vestibular nerve branches were studied in individuals of varying ages. It was found that the peripheral endings of the vestibular nerve form a complicated pattern inside the vestibular sensory epithelia. A detailed description of the sensory cells and their surface organelles is included.

  16. Systematic Desensitization as Training in Self-Control

    ERIC Educational Resources Information Center

    Goldfried, Marvin R.

    1971-01-01

    A description of a mediational model to explain the effectiveness of desensitization and a discussion of the available corroborative research findings for this alternative explanation are given. Also, specific procedural modifications for systematic desensitization are suggested. (Author)

  17. Desensitized nicotinic receptors in brain Hai Wanga,*, Xiulan Sunb

    E-print Network

    Cooper, Robin L.

    following prolonged or repetitive stimulation. Nicotinic acetylcholine receptors (nAChRs), as a member: Acetylcholine receptors: nicotinic Keywords: Nicotinic receptors; Desensitize; Nicotine Contents 1. Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 424 5.3. Ligand contribute to nicotinic receptors desensitization

  18. Playing violent video games and desensitization to violence.

    PubMed

    Brockmyer, Jeanne Funk

    2015-01-01

    This article examines current research linking exposure to violent video games and desensitization to violence. Data from questionnaire, behavioral, and psychophysiologic research are reviewed to determine if exposure to violent video games is a risk factor for desensitization to violence. Real-world implications of desensitization are discussed. PMID:25455576

  19. Modeling Shock Desensitization of Composition B Explosive

    NASA Astrophysics Data System (ADS)

    Mader, Charles

    2014-03-01

    The NOBEL multimaterial adaptive grid Eulerian hydrodynamic code was used to model a shaped charge jet formation, its interaction with a steel plate, and shock formation of a bow shock in front of the jet that shocks and desensitizes a cylinder of Composition B (60/40 RDX/TNT at 1.715 g/cc) explosive so that when the jet arrives it fails to initiate detonation in the desensitized explosive. The jet passes through the Composition B explosive cylinder, an air gap, and then initiates propagating detonation in a second Composition B explosive cylinder that has not been desensitized by a preshock. The experimental arrangement was studied using X-ray radiography at the Material Research Laboratory in Melbourne, Australia.

  20. Nerve injury induces a new profile of tactile and mechanical nociceptor input from undamaged peripheral afferents.

    PubMed

    Boada, M Danilo; Gutierrez, Silvia; Aschenbrenner, Carol A; Houle, Timothy T; Hayashida, Ken-Ichiro; Ririe, Douglas G; Eisenach, James C

    2015-01-01

    Chronic pain after nerve injury is often accompanied by hypersensitivity to mechanical stimuli, yet whether this reflects altered input, altered processing, or both remains unclear. Spinal nerve ligation or transection results in hypersensitivity to mechanical stimuli in skin innervated by adjacent dorsal root ganglia, but no previous study has quantified the changes in receptive field properties of these neurons in vivo. To address this, we recorded intracellularly from L4 dorsal root ganglion neurons of anesthetized young adult rats, 1 wk after L5 partial spinal nerve ligation (pSNL) or sham surgery. One week after pSNL, hindpaw mechanical withdrawal threshold in awake, freely behaving animals was decreased in the L4 distribution on the nerve-injured side compared with sham controls. Electrophysiology revealed that high-threshold mechanoreceptive cells of A-fiber conduction velocity in L4 were sensitized, with a seven-fold reduction in mechanical threshold, a seven-fold increase in receptive field area, and doubling of maximum instantaneous frequency in response to peripheral stimuli, accompanied by reductions in after-hyperpolarization amplitude and duration. Only a reduction in mechanical threshold (minimum von Frey hair producing neuronal activity) was observed in C-fiber conduction velocity high-threshold mechanoreceptive cells. In contrast, low-threshold mechanoreceptive cells were desensitized, with a 13-fold increase in mechanical threshold, a 60% reduction in receptive field area, and a 40% reduction in instantaneous frequency to stimulation. No spontaneous activity was observed in L4 ganglia, and the likelihood of recording from neurons without a mechanical receptive field was increased after pSNL. These data suggest massively altered input from undamaged sensory afferents innervating areas of hypersensitivity after nerve injury, with reduced tactile and increased nociceptive afferent response. These findings differ importantly from previous preclinical studies, but are consistent with clinical findings in most patients with chronic neuropathic pain. PMID:25274350

  1. Desensitizing nano powders to electrostatic discharge ignition

    SciTech Connect

    Steelman, Ryan; Clark, Billy; Pantoya, Michelle L.; Heaps, Ronald J.; Daniels, Michael A.

    2015-08-01

    Electrostatic discharge (ESD) is a main cause for ignition in powder media ranging from grain silos to fireworks. Nanoscale particles are orders of magnitude more ESD ignition sensitive than their micron scale counterparts. This study shows that at least 13 vol. % carbon nanotubes (CNT) added to nano-aluminum and nano-copper oxide particles (nAl + CuO) eliminates ESD ignition sensitivity. The CNT act as a conduit for electric energy and directs electric charge through the powder to desensitize the reactive mixture to ignition. For nanoparticles, the required CNT concentration for desensitizing ESD ignition acts as a diluent to quench energy propagation.

  2. Clinical application of sensory protection of denervated muscle.

    PubMed

    Bain, James R; Hason, Yaniv; Veltri, Karen; Fahnestock, Margaret; Quartly, Caroline

    2008-11-01

    Following proximal peripheral nerve injury, motor recovery is often poor due to prolonged muscle denervation and loss of regenerative potential. The transfer of a sensory nerve to denervated muscle results in improved functional recovery in experimental models. The authors here report the first clinical case of sensory protection. Following a total hip arthroplasty, this patient experienced a complete sciatic nerve palsy with no recovery at 3 months postsurgery and profound denervation confirmed electrodiagnostically. He underwent simultaneous neurolysis of the sciatic nerve and saphenous nerve transfers to the tibialis anterior branch of the peroneal nerve and gastrocnemius branch from the tibial nerve. He noted an early proprioceptive response. Electromyography demonstrated initially selective amelioration of denervation potentials followed by improved motor recovery in sensory protected muscles only. The patient reported clinically significant functional improvements in activities of daily living. The authors hypothesize that the presence of a sensory nerve during muscle denervation can improve functional motor recovery. PMID:18976091

  3. Clinical application of sensory protection of denervated muscle

    PubMed Central

    Bain, James R.; Hason, Yaniv; Veltri, Karen; Fahnestock, Margaret; Quartly, Caroline

    2012-01-01

    Following proximal peripheral nerve injury, motor recovery is often poor due to prolonged muscle denervation and loss of regenerative potential. The transfer of a sensory nerve to denervated muscle results in improved functional recovery in experimental models. The authors here report the first clinical case of sensory protection. Following a total hip arthroplasty, this patient experienced a complete sciatic nerve palsy with no recovery at 3 months postsurgery and profound denervation confirmed electrodiagnostically. He underwent simultaneous neurolysis of the sciatic nerve and saphenous nerve transfers to the tibialis anterior branch of the peroneal nerve and gastrocnemius branch from the tibial nerve. He noted an early proprioceptive response. Electromyography demonstrated initially selective amelioration of denervation potentials followed by improved motor recovery in sensory protected muscles only. The patient reported clinically significant functional improvements in activities of daily living. The authors hypothesize that the presence of a sensory nerve during muscle denervation can improve functional motor recovery. PMID:18976091

  4. Electrophysiological evaluation of nerve function in inferior alveolar nerve injury: relationship between nerve action potentials and histomorphometric observations.

    PubMed

    Murayama, M; Sasaki, K; Shibahara, T

    2015-12-01

    The objective of this study was to improve the accuracy of diagnosis of inferior alveolar nerve (IAN) injury by determining degrees of nerve disturbance using the sensory nerve action potential (SNAP) and sensory nerve conduction velocity (SCV). Crush and partial and complete nerve amputation injuries were applied to the IAN of rabbits, then SNAPs and histomorphometric observations were recorded at 1, 5, and 10 weeks. For crush injury, most nerves were smaller in diameter at 5 weeks than at 1 week, however after 10 weeks, extensive nerve regeneration was observed. The SNAP showed a decrease in SCV at weeks 1 and 5, followed by an increase at week 10. For partial nerve amputation, small to medium-sized nerve fibres were observed at weeks 1 and 5, then larger nerves were seen at week 10. Minimal changes in SCV were observed at weeks 1 and 5, however SCV increased at week 10. For complete nerve amputation, nerve fibres were sparse at week 1, but gradual nerve regeneration was observed at weeks 5 and 10. SNAPs were detectable from week 10, however the SCV was extremely low. This study showed SCV to be an effective factor in the evaluation of nerve injury and regeneration. PMID:26433750

  5. Desensitization and recovery of metastable intermolecular composites

    DOEpatents

    Busse, James R. (South Fork, CO); Dye, Robert C. (Los Alamos, NM); Foley, Timothy J. (Los Alamos, NM); Higa, Kelvin T. (Ridgecrest, CA); Jorgensen, Betty S. (Jemez Springs, NM); Sanders, Victor E. (White Rock, NM); Son, Steven F. (Los Alamos, NM)

    2010-09-07

    A method to substantially desensitize a metastable intermolecular composite material to electrostatic discharge and friction comprising mixing the composite material with an organic diluent and removing enough organic diluent from the mixture to form a mixture with a substantially putty-like consistency, as well as a concomitant method of recovering the metastable intermolecular composite material.

  6. Neonatal desensitization allows long-term

    E-print Network

    Cai, Long

    for long-term immune protection of human fetal and stem cell­derived neural cells transplanted embryonic stem cell­derived neural precursor (hES-N) cells. Human fetal tissues were collected by donation to achieve long-term survival of human neural grafts in the adult mammalian brain, based on desensitizing

  7. Rehabilitation of the trigeminal nerve

    PubMed Central

    Iro, Heinrich; Bumm, Klaus; Waldfahrer, Frank

    2005-01-01

    When it comes to restoring impaired neural function by means of surgical reconstruction, sensory nerves have always been in the role of the neglected child when compared with motor nerves. Especially in the head and neck area, with its either sensory, motor or mixed cranial nerves, an impaired sensory function can cause severe medical conditions. When performing surgery in the head and neck area, sustaining neural function must not only be highest priority for motor but also for sensory nerves. In cases with obvious neural damage to sensory nerves, an immediate neural repair, if necessary with neural interposition grafts, is desirable. Also in cases with traumatic trigeminal damage, an immediate neural repair ought to be considered, especially since reconstructive measures at a later time mostly require for interposition grafts. In terms of the trigeminal neuralgia, commonly thought to arise from neurovascular brainstem compression, a pharmaceutical treatment is considered as the state of the art in terms of conservative therapy. A neurovascular decompression of the trigeminal root can be an alternative in some cases when surgical treatment is sought after. Besides the above mentioned therapeutic options, alternative treatments are available. PMID:22073060

  8. ?-Synuclein in cutaneous autonomic nerves

    PubMed Central

    Wang, Ningshan; Gibbons, Christopher H.; Lafo, Jacob

    2013-01-01

    Objective: To develop a cutaneous biomarker for Parkinson disease (PD). Methods: Twenty patients with PD and 14 age- and sex-matched control subjects underwent examinations, autonomic testing, and skin biopsies at the distal leg, distal thigh, and proximal thigh. ?-Synuclein deposition and the density of intraepidermal, sudomotor, and pilomotor nerve fibers were measured. ?-Synuclein deposition was normalized to nerve fiber density (the ?-synuclein ratio). Results were compared with examination scores and autonomic function testing. Results: Patients with PD had a distal sensory and autonomic neuropathy characterized by loss of intraepidermal and pilomotor fibers (p < 0.05 vs controls, all sites) and morphologic changes to sudomotor nerve fibers. Patients with PD had greater ?-synuclein deposition and higher ?-synuclein ratios compared with controls within pilomotor nerves and sudomotor nerves (p < 0.01, all sites) but not sensory nerves. Higher ?-synuclein ratios correlated with Hoehn and Yahr scores (r = 0.58–0.71, p < 0.01), with sympathetic adrenergic function (r = ?0.40 to ?0.66, p < 0.01), and with parasympathetic function (r = ?0.66 to ?0.77, p > 0.01). Conclusions: We conclude that ?-synuclein deposition is increased in cutaneous sympathetic adrenergic and sympathetic cholinergic fibers but not sensory fibers of patients with PD. Higher ?-synuclein deposition is associated with greater autonomic dysfunction and more advanced PD. These data suggest that measures of ?-synuclein deposition in cutaneous autonomic nerves may be a useful biomarker in patients with PD. PMID:24089386

  9. Sensory pathophysiology in chronic acquired demyelinating neuropathy.

    PubMed

    Krarup, C; Trojaborg, W

    1996-02-01

    Pathophysiological changes in sensory fibres in chronic acquired demyelinating neuropathy (CADP) are poorly understood, and it is not known to what extent sensory loss may be due to axonal loss or to conduction block. Motor and sensory nerve condition were studied in 18 patients with CADP to delineate abnormalities in the compound sensory action potential (CSAP) recorded proximally along the limb. To distinguish small CSAPs from noise, near-nerve needle electrodes and electronic averaging were used. In all, 58 motor and 78 sensory nerves in the upper and lower limbs were studied, and in 29 nerves, motor and sensory conduction was compared over the same proximal and distal segments of the upper limbs. The proximal/distal amplitude ratio (P/D ratio) of the compound muscle action potential (CMAP) was reduced in 76% of the nerves compared with only 21% of the CSAPs. The amplitudes of CMAPs evoked and of CSAPs recorded distally were reduced to the same extent. The prolongation of the distal motor latency (DML) was linearly related to the reduction in amplitude of the CMAP whereas reduction of the distal sensory conduction velocity (SCVd) mainly occurred if the amplitude of the CSAP was reduced more than 70%. The proximal motor nerve conduction velocity (MCVp) was reduced by 40-50%, twice as much as the reduction in distal MCV (MCVd) (calculated from the reciprocal DML), and related to the reduction in the P/D ratio of the CMAP. The proximal SCV (SCVp) decreased approximately 20%, similar to the reduction in SCVd and out of proportion to the marked reduction of the MCVp. The results suggest different pathophysiological changes in sensory and motor fibres in CADP. Thus, nerve fibre loss could account for most of the abnormal parameters in sensory conduction, whereas demyelination was the dominating cause of motor nerve dysfunction. PMID:8624687

  10. Anatomic variations in sensory innervation of the hand and digits.

    PubMed

    Bas, H; Kleinert, J M

    1999-11-01

    Anatomic dissections under microscopic magnification were performed on 30 fresh cadaveric hands to depict the course and interconnections of the sensory nerves to the digits. The dissections included the median nerve, the ulnar nerve, the superficial branch of the radial nerve, the dorsal branch of the ulnar nerve, and the dorsal branch of the proper digital nerve. The communicating branches between the median and ulnar nerves in the palm were found in 20 of the 30 (67%) specimens. The dorsal branch of the proper digital nerve was found to arise at or proximal to the A1 pulley zone in 62% of the long digits, more proximally than previously reported. The dorsal sensory nerves (the terminal branch of radial or ulnar sensory nerves) extending to the nail bed area were found in 46% of the digits, thus confirming that sensory supply to the dorsum of the distal phalanx and nail bed also arises from the dorsal sensory nerves. Four types of palmar-dorsal interconnections, located in the middle of the proximal phalanx, were found in the digits but not in the thumb. The presence of these branches indicates dual innervation of the dorsal and palmar side of the distal areas of the digits. These anatomic findings may help hand surgeons interpret discrepancies in sensory loss after either dorsal or palmar injuries. PMID:10584938

  11. Desensitization and recovery of phototropic responsiveness in Arabidopsis thaliana

    NASA Technical Reports Server (NTRS)

    Janoudi, A. K.; Poff, K. L.

    1993-01-01

    Phototropism is induced by blue light, which also induces desensitization, a partial or total loss of phototropic responsiveness. The fluence and fluence-rate dependence of desensitization and recovery from desensitization have been measured for etiolated and red light (669-nm) preirradiated Arabidopsis thaliana seedlings. The extent of desensitization increased as the fluence of the desensitizing 450-nm light was increased from 0.3 to 60 micromoles m-2 s-1. At equal fluences, blue light caused more desensitization when given at a fluence rate of 1.0 micromole m-2 s-1 than at 0.3 micromole m-2 s-1. In addition, seedlings irradiated with blue light at the higher fluence rate required a longer recovery time than seedlings irradiated at the lower fluence rate. A red light preirradiation, probably mediated via phytochrome, decreased the time required for recovery from desensitization. The minimum time for detectable recovery was about 65 s, and the maximum time observed was about 10 min. It is proposed that the descending arm of the fluence-response relationship for first positive phototropism is a consequence of desensitization, and that the time threshold for second positive phototropism establishes a period during which recovery from desensitization occurs.

  12. [Sensory sensitization, part II: Pathophysiology in dysfunctional disorders. Understanding the inner life of the nerve pathways may explain hitherto unexplainable symptoms].

    PubMed

    Levander, Hans

    2003-04-30

    This article is based on a vast clinical experience from patients presenting with widespread pain syndromes as well as dysfunctional symptoms from inner organs. A literature survey has been performed. Allodynia and hyperalgesia that partly explain the fibromyalgia and local myalgia syndromes seem to arise from a pathophysiological process of nociceptive sensitisation. It is proposed that the concept of "sensory sensitisation dysfunctional disorders" be applied to conditions like bronchial hyperreactivity, Da Costas syndrome, Dercum's disease (Adipositas dolorosa), dry eyes and mouth syndrome, fibromyalgia, gastralgia, globus hystericus, interstitial cystitis, chronic prostatitis, irritable bowel syndrome, photo- and phonosensitivity, rhinitis, tension headache, tinnitus, vestibulitis syndrome. These dysfunctional disorders cannot be satisfactorily explained by presently known pathophysiological models like ongoing inflammatory process, tissue degeneration, fibrosis, blood vessel diseases, tumours, immune reactions, toxic or deficiency conditions, metabolic disturbances. Neurogenic mechanisms also seem to play an important role in the pathophysiology of arthritic conditions, and might be worthwhile to include in forthcoming discussions concerning the aetiology of chronic inflammatory disease. PMID:12789809

  13. Peripheral nerve conduits: technology update

    PubMed Central

    Arslantunali, D; Dursun, T; Yucel, D; Hasirci, N; Hasirci, V

    2014-01-01

    Peripheral nerve injury is a worldwide clinical problem which could lead to loss of neuronal communication along sensory and motor nerves between the central nervous system (CNS) and the peripheral organs and impairs the quality of life of a patient. The primary requirement for the treatment of complete lesions is a tension-free, end-to-end repair. When end-to-end repair is not possible, peripheral nerve grafts or nerve conduits are used. The limited availability of autografts, and drawbacks of the allografts and xenografts like immunological reactions, forced the researchers to investigate and develop alternative approaches, mainly nerve conduits. In this review, recent information on the various types of conduit materials (made of biological and synthetic polymers) and designs (tubular, fibrous, and matrix type) are being presented. PMID:25489251

  14. Galvanic Skin Response and Reported Anxiety During Systematic Desensitization

    ERIC Educational Resources Information Center

    Hyman, Edward T.; Gale, Elliot N.

    1973-01-01

    The purpose of the present study was to investigate the GSR during systematic desensitization. Three groups of females each were preselected for high snake fear. Outcome measures indicated that the desensitization group reduced phobic behavior most, followed by the relaxation group, and then the exposure groups. (Author)

  15. How do tonic glutamatergic synapses evade receptor desensitization?

    PubMed Central

    Pang, Ji-Jie; Gao, Fan; Barrow, Andrew; Jacoby, Roy A; Wu, Samuel M

    2008-01-01

    Photoreceptor output synapses are the best known tonic chemical synapses in the nervous system, in which glutamate is continuously released in darkness, activating AMPA/kainate receptors in postsynaptic neurons. It has been shown that glutamate receptors in certain types of second-order retinal cells are largely desensitized in darkness, leading to small postsynaptic currents and reduced response dynamic ranges. Here we show that the tonic glutamatergic synapses between photoreceptors and rod-dominated hyperpolarizing bipolar cells (HBCRs) in the salamander retina evade postsynaptic receptor desensitization by using (1) multiple invaginating ribbon junctions as releasing sites for low-frequency, synchronized multiquantal release at each site; and (2) the GluR4 AMPA receptors as the postsynaptic receptors. The multiquantal events exhibit faster decay time than the GluR4 receptor desensitization time constant and therefore self-desensitization is minimized, and the average inter-event duration in darkness is much longer than the GluR4 desensitization recovery time and thus mutual desensitization is avoided. Consequently, the HBCRs are not desensitized in darkness, allowing light signals to be encoded by the full operating range of the glutamate-gated postsynaptic currents. Our study illustrates for the first time how a tonic glutamatergic synapse avoids postsynaptic receptor desensitization, a strategy that may be shared by many other synapses in the nervous system that need extended operation capacity. PMID:18420706

  16. EMG Biofeedback Training Versus Systematic Desensitization for Test Anxiety Reduction

    ERIC Educational Resources Information Center

    Romano, John L.; Cabianca, William A.

    1978-01-01

    Biofeedback training to reduce test anxiety among university students was investigated. Biofeedback training with systematic desensitization was compared to an automated systematic desensitization program not using EMG feedback. Biofeedback training is a useful technique for reducing test anxiety, but not necessarily more effective than systematic…

  17. Nerve Cross-Bridging to Enhance Nerve Regeneration in a Rat Model of Delayed Nerve Repair

    PubMed Central

    2015-01-01

    There are currently no available options to promote nerve regeneration through chronically denervated distal nerve stumps. Here we used a rat model of delayed nerve repair asking of prior insertion of side-to-side cross-bridges between a donor tibial (TIB) nerve and a recipient denervated common peroneal (CP) nerve stump ameliorates poor nerve regeneration. First, numbers of retrogradely-labelled TIB neurons that grew axons into the nerve stump within three months, increased with the size of the perineurial windows opened in the TIB and CP nerves. Equal numbers of donor TIB axons regenerated into CP stumps either side of the cross-bridges, not being affected by target neurotrophic effects, or by removing the perineurium to insert 5-9 cross-bridges. Second, CP nerve stumps were coapted three months after inserting 0-9 cross-bridges and the number of 1) CP neurons that regenerated their axons within three months or 2) CP motor nerves that reinnervated the extensor digitorum longus (EDL) muscle within five months was determined by counting and motor unit number estimation (MUNE), respectively. We found that three but not more cross-bridges promoted the regeneration of axons and reinnervation of EDL muscle by all the CP motoneurons as compared to only 33% regenerating their axons when no cross-bridges were inserted. The same 3-fold increase in sensory nerve regeneration was found. In conclusion, side-to-side cross-bridges ameliorate poor regeneration after delayed nerve repair possibly by sustaining the growth-permissive state of denervated nerve stumps. Such autografts may be used in human repair surgery to improve outcomes after unavoidable delays. PMID:26016986

  18. The desensitization gate of inhibitory Cys-loop receptors

    NASA Astrophysics Data System (ADS)

    Gielen, Marc; Thomas, Philip; Smart, Trevor G.

    2015-04-01

    Cys-loop neurotransmitter-gated ion channels are vital for communication throughout the nervous system. Following activation, these receptors enter into a desensitized state in which the ion channel shuts even though the neurotransmitter molecules remain bound. To date, the molecular determinants underlying this most fundamental property of Cys-loop receptors have remained elusive. Here we present a generic mechanism for the desensitization of Cys-loop GABAA (GABAARs) and glycine receptors (GlyRs), which both mediate fast inhibitory synaptic transmission. Desensitization is regulated by interactions between the second and third transmembrane segments, which affect the ion channel lumen near its intracellular end. The GABAAR and GlyR pore blocker picrotoxin prevented desensitization, consistent with its deep channel-binding site overlapping a physical desensitization gate.

  19. Esophagoprotective activity of angiotensin-(1-7) in experimental model of acute reflux esophagitis. Evidence for the role of nitric oxide, sensory nerves, hypoxia-inducible factor-1alpha and proinflammatory cytokines.

    PubMed

    Pawlik, M W; Kwiecien, S; Pajdo, R; Ptak-Belowska, A; Brzozowski, B; Krzysiek-Maczka, G; Strzalka, M; Konturek, S J; Brzozowski, T

    2014-12-01

    Gastroesophageal reflux disease (GERD) is a global disease rapidly increasing among world population. The pathogenesis of reflux esophagitis which is considered as the early stage of GERD is complex, resulting from an imbalance between aggressive factors damaging the esophagus and a number of the natural defense mechanisms. The esophageal mucosa is in a state of continuous exposure to potentially damaging endogenous and exogenous factors. Important aggressive components of gastric refluxate include acid and pepsin and also pancreatic enzymes and bile. Among aggressive factors of exogenous origin, cigarette smoking, non-steroidal anti-inflammatory drugs (NSAID), and steroids are of the utmost importance. The basic level of esophageal defense against acid-pepsin damage consists of the anti-reflux mechanisms such as the luminal acid clearance and removal of the esophageal contents and neutralization of luminal acidity. In addition the esophageal mucosal protection includes the presence of pre-epithelial, epithelial and post-epithelial cellular and functional components. Recently, the progress have been made in the understanding of role of the heptapeptide member of the renin-angiotensin system (RAS), angiotensin-(1-7) (Ang-(1-7)) in the control of gastrointestinal functions. It has been shown that all components of local RAS including Ang-(1-7) are detectable in the gastrointestinal wall including not only the stomach but also the esophagus. Previous studies revealed that Ang-(1-7), which is an important component of the RAS, exerts vasodilatory, anti-inflammatory and antioxidant activities in the stomach. Ang-(1-7) was recently implicated in gastroprotection, but its effects on esophageal mucosa in a rodent model of reflux esophagitis and in human subjects presenting GERD symptoms have not been explored. The present study was aimed to evaluate the possible protective effects of Ang-(1-7) and Mas-receptors upon esophageal mucosal damage in acute reflux esophagitis (RE) induced in anesthetized rats by ligating the pylorus and the limiting ridge (a transitional region between the forestomach and the corpus of stomach). Consequently, the total gastric reservoir to store gastric juice was greatly diminished, resulting in the reflux of this juice into the esophagus. Because Mas receptors are functionally linked to nitric oxide (NO) formation, we also studied involvement of endogenous NO in the mediation of protective and circulatory effects of exogenous Ang-(1-7). Moreover, an attempt was made to assess the possible role of sensory neurons in the modulation of the protective effects exerted by Ang-(1-7)/Mas receptor system. Six series of rats were pretreated 30 min before induction of RE with 1) vehicle (saline), 2) Ang-(1-7) (5-50 ?g/kg i.p.), 3) A779 (50 ?g/kg i.p.), the selective Mas receptor antagonist applied alone, 4) Ang-(1-7) (50 ?g/kg i.p.) combined with A779, 5) L-NNA (20 mg/kg i.p.) administered alone, and 6) Ang-(1-7) (50 ?g/kg i.p.) combined with L-NNA. In separate group of rats, capsaicin (total dosage of 125 mg/kg within three days) was administered s.c. 2 weeks before the induction of RE to induce functional ablation of sensory nerves. Rats with intact sensory nerves and those with capsaicin-induced sensory denervation received vehicle (saline) or Ang-(1-7) (50 ?g/kg i.p.) to determine whether this vasoactive metabolite of angiotensin I could be also effective in rats with capsaicin-induced impairment of the synthesis and release of sensory neuropeptides such as CGRP. Four hours after induction of RE, the mucosal damage was graded with mucosal lesion index (LI) from 0 to 6, the esophageal microcirculatory blood flow (EBF) was determined by H2-gas clearance technique and plasma level of pro-inflammatory cytokines interleukin-1b (IL-1?), and tumor necrosis factor-? (TNF-?) was determined by ELISA. The expression of proinflammatory factors including COX-2, cytokine IL-1? and hypoxia inducible factor 1alpha (Hif1?) was analyzed in the esophageal mucosal biopsies. In rats with RE, the esophageal LI was signi

  20. The Role of Cutaneous Innervation in the Sensory Abnormalities Associated with Diabetic Neuropathy

    E-print Network

    Johnson, Megan Sarah

    2008-05-05

    Diabetes-induced nerve damage results in cutaneous denervation, nerve conduction slowing, suppressed regenerative responses, and debilitating painful or insensate sensory symptoms. The increasing prevalence of diabetic neuropathy and its persistent...

  1. Nerve coaptation studies with and without a gap in rabbits.

    PubMed

    Hasegawa, J; Shibata, M; Takahashi, H

    1996-03-01

    Appropriate matching of proximal and distal fibers is a major objective when suturing a lacerated nerve. Recent studies suggest that neurotropic factors may influence motor/sensory specificity and affect the functional outcome. This was studied in animal models by direct coaptation of cut nerve ends inside a 5-mm collagen tube with and without appropriate sensory/motor alignment, as well as in models where the cut nerve ends were placed in a 10-mm collagen tube with a 5-mm gap, with and without appropriate sensory/motor alignment. The radial nerve of 49 New Zealand white rabbits was chosen because it has distinct motor and sensory divisions. The animals were killed at 24 weeks and electrophysiologic, histologic, and muscle contraction studies were performed. Axon counts and diameters were measured from the distal motor and sensory stumps. Nerve conduction velocity, dry muscle weight, and motor axon counts were not statistically different between the groups. The malaligned group without a gap had better regeneration in sensory nerves than other groups. The muscle contraction force of the malaligned group without a gap was significantly less than the other groups. The malaligned group with a 5-mm gap had the same muscle contraction force as the aligned group without a gap. In this study, a short nerve gap lessened the misdirection of motor fibers after nerve-end coaptation. PMID:8683059

  2. The Sensory Neurons of Touch Victoria E. Abraira1 and David D. Ginty1,*

    E-print Network

    Alford, Simon

    of sensory modalities (Mu¨ ller, 1842), prompting us to ask whether nerves that convey different qualities dorsal root ganglia (DRG) and cranial sensory ganglia. DRG neurons are pseudouni- polar, with one axonal

  3. Desensitization for solid organ and hematopoietic stem cell transplantation

    PubMed Central

    Zachary, Andrea A; Leffell, Mary S

    2014-01-01

    Desensitization protocols are being used worldwide to enable kidney transplantation across immunologic barriers, i.e. antibody to donor HLA or ABO antigens, which were once thought to be absolute contraindications to transplantation. Desensitization protocols are also being applied to permit transplantation of HLA mismatched hematopoietic stem cells to patients with antibody to donor HLA, to enhance the opportunity for transplantation of non-renal organs, and to treat antibody-mediated rejection. Although desensitization for organ transplantation carries an increased risk of antibody-mediated rejection, ultimately these transplants extend and enhance the quality of life for solid organ recipients, and desensitization that permits transplantation of hematopoietic stem cells is life saving for patients with limited donor options. Complex patient factors and variability in treatment protocols have made it difficult to identify, precisely, the mechanisms underlying the downregulation of donor-specific antibodies. The mechanisms underlying desensitization may differ among the various protocols in use, although there are likely to be some common features. However, it is likely that desensitization achieves a sort of immune detente by first reducing the immunologic barrier and then by creating an environment in which an autoregulatory process restricts the immune response to the allograft. PMID:24517434

  4. Sensory development.

    PubMed

    Clark-Gambelunghe, Melinda B; Clark, David A

    2015-04-01

    Sensory development is complex, with both morphologic and neural components. Development of the senses begins in early fetal life, initially with structures and then in-utero stimulation initiates perception. After birth, environmental stimulants accelerate each sensory organ to nearly complete maturity several months after birth. Vision and hearing are the best studied senses and the most crucial for learning. This article focuses on the cranial senses of vision, hearing, smell, and taste. Sensory function, embryogenesis, external and genetic effects, and common malformations that may affect development are discussed, and the corresponding sensory organs are examined and evaluated. PMID:25836703

  5. Three-dimensional Reconstruction of Peripheral Nerve Internal Fascicular Groups.

    PubMed

    Zhong, Yingchun; Wang, Liping; Dong, Jianghui; Zhang, Yi; Luo, Peng; Qi, Jian; Liu, Xiaolin; Xian, Cory J

    2015-01-01

    Peripheral nerves are important pathways for receiving afferent sensory impulses and sending out efferent motor instructions, as carried out by sensory nerve fibers and motor nerve fibers. It has remained a great challenge to functionally reconnect nerve internal fiber bundles (or fascicles) in nerve repair. One possible solution may be to establish a 3D nerve fascicle visualization system. This study described the key technology of 3D peripheral nerve fascicle reconstruction. Firstly, fixed nerve segments were embedded with position lines, cryostat-sectioned continuously, stained and imaged histologically. Position line cross-sections were identified using a trained support vector machine method, and the coordinates of their central pixels were obtained. Then, nerve section images were registered using the bilinear method, and edges of fascicles were extracted using an improved gradient vector flow snake method. Subsequently, fascicle types were identified automatically using the multi-directional gradient and second-order gradient method. Finally, a 3D virtual model of internal fascicles was obtained after section images were processed. This technique was successfully applied for 3D reconstruction for the median nerve of the hand-wrist and cubital fossa regions and the gastrocnemius nerve. This nerve internal fascicle 3D reconstruction technology would be helpful for aiding peripheral nerve repair and virtual surgery. PMID:26596642

  6. Three-dimensional Reconstruction of Peripheral Nerve Internal Fascicular Groups

    PubMed Central

    Zhong, Yingchun; Wang, Liping; Dong, Jianghui; Zhang, Yi; Luo, Peng; Qi, Jian; Liu, Xiaolin; Xian, Cory J.

    2015-01-01

    Peripheral nerves are important pathways for receiving afferent sensory impulses and sending out efferent motor instructions, as carried out by sensory nerve fibers and motor nerve fibers. It has remained a great challenge to functionally reconnect nerve internal fiber bundles (or fascicles) in nerve repair. One possible solution may be to establish a 3D nerve fascicle visualization system. This study described the key technology of 3D peripheral nerve fascicle reconstruction. Firstly, fixed nerve segments were embedded with position lines, cryostat-sectioned continuously, stained and imaged histologically. Position line cross-sections were identified using a trained support vector machine method, and the coordinates of their central pixels were obtained. Then, nerve section images were registered using the bilinear method, and edges of fascicles were extracted using an improved gradient vector flow snake method. Subsequently, fascicle types were identified automatically using the multi-directional gradient and second-order gradient method. Finally, a 3D virtual model of internal fascicles was obtained after section images were processed. This technique was successfully applied for 3D reconstruction for the median nerve of the hand-wrist and cubital fossa regions and the gastrocnemius nerve. This nerve internal fascicle 3D reconstruction technology would be helpful for aiding peripheral nerve repair and virtual surgery. PMID:26596642

  7. Stem cell salvage of injured peripheral nerve.

    PubMed

    Grimoldi, Nadia; Colleoni, Federica; Tiberio, Francesca; Vetrano, Ignazio G; Cappellari, Alberto; Costa, Antonella; Belicchi, Marzia; Razini, Paola; Giordano, Rosaria; Spagnoli, Diego; Pluderi, Mauro; Gatti, Stefano; Morbin, Michela; Gaini, Sergio M; Rebulla, Paolo; Bresolin, Nereo; Torrente, Yvan

    2015-01-01

    We previously developed a collagen tube filled with autologous skin-derived stem cells (SDSCs) for bridging long rat sciatic nerve gaps. Here we present a case report describing a compassionate use of this graft for repairing the polyinjured motor and sensory nerves of the upper arms of a patient. Preclinical assessment was performed with collagen/SDSC implantation in rats after sectioning the sciatic nerve. For the patient, during the 3-year follow-up period, functional recovery of injured median and ulnar nerves was assessed by pinch gauge test and static two-point discrimination and touch test with monofilaments, along with electrophysiological and MRI examinations. Preclinical experiments in rats revealed rescue of sciatic nerve and no side effects of patient-derived SDSC transplantation (30 and 180 days of treatment). In the patient treatment, motor and sensory functions of the median nerve demonstrated ongoing recovery postimplantation during the follow-up period. The results indicate that the collagen/SDSC artificial nerve graft could be used for surgical repair of larger defects in major lesions of peripheral nerves, increasing patient quality of life by saving the upper arms from amputation. PMID:24268028

  8. Mechanism of action of a desensitizing fluoride toothpaste delivering calcium and phosphate ingredients in the treatment of dental hypersensitivity. Part III: Prevention of dye penetration through dentin vs a calcium- and phosphate-free control.

    PubMed

    Winston, Anthony E; Charig, Andrew J; Thong, Stephen

    2010-01-01

    It is generally accepted that the pain of dental hypersensitivity resulting from gum recession is from the movement of fluid within the exposed tubules of dentin, causing changes in pressure on the nerve within the pulpal cavity. One method of treating hypersensitivity is to occlude the tubules, preventing fluid movement. This article discusses the use of a dye penetration technique, which establishes this mechanism of action for a desensitizing fluoride toothpaste containing calcium and phosphate. Two groups of intact teeth were perfectly sealed with enamel paint. Windows 100-micro to 200-micro deep were opened on opposite sides of each tooth at the dentin-enamel junction and briefly etched using 20% polyacrylic acid. One batch of teeth was treated eight times for 30 mins each with a 1:3 slurry of the desensitizing toothpaste and another set with a similar slurry prepared from a calcium- and phosphate-free control. A 0.85% aqueous solution of acid red fuchsin dye was applied to each window and allowed to dry. After a brief rinse, the teeth were sectioned across the windows. Almost no dye penetration was seen in teeth treated with the desensitizing toothpaste; however, extensive penetration through the dentin was visible in the control-treated teeth. The differences in dye penetration for the two sets of teeth were significant by both subjective (P < .001) and objective (P < .01) measures. Tubule occlusion because of calcium and phosphate ions from the desensitizing toothpaste accounts for its tooth desensitizing efficacy. PMID:20158016

  9. THE ROLE OF GLYOXALASE I IN HYPERGLYCEMIA-INDUCED SENSORY NEURON DAMAGE AND DEVELOPMENT OF DIABETIC SENSORY NEUROPATHY SYMPTOMS

    E-print Network

    Jack, Megan Marie

    2011-08-31

    Diabetic neuropathy is the most common and debilitating complication of diabetes mellitus with over half of all patients developing altered sensation as a result of damage to peripheral sensory neurons. Hyperglycemia results in altered nerve...

  10. Peripheral nerve hyperexcitability syndromes.

    PubMed

    Küçükali, Cem Ismail; Kürtüncü, Murat; Akçay, Halil ?brahim; Tüzün, Erdem; Öge, Ali Emre

    2015-01-01

    Peripheral nerve hyperexcitability (PNH) syndromes can be subclassified as primary and secondary. The main primary PNH syndromes are neuromyotonia, cramp-fasciculation syndrome (CFS), and Morvan's syndrome, which cause widespread symptoms and signs without the association of an evident peripheral nerve disease. Their major symptoms are muscle twitching and stiffness, which differ only in severity between neuromyotonia and CFS. Cramps, pseudomyotonia, hyperhidrosis, and some other autonomic abnormalities, as well as mild positive sensory phenomena, can be seen in several patients. Symptoms reflecting the involvement of the central nervous system occur in Morvan's syndrome. Secondary PNH syndromes are generally seen in patients with focal or diffuse diseases affecting the peripheral nervous system. The PNH-related symptoms and signs are generally found incidentally during clinical or electrodiagnostic examinations. The electrophysiological findings that are very useful in the diagnosis of PNH are myokymic and neuromyotonic discharges in needle electromyography along with some additional indicators of increased nerve fiber excitability. Based on clinicopathological and etiological associations, PNH syndromes can also be classified as immune mediated, genetic, and those caused by other miscellaneous factors. There has been an increasing awareness on the role of voltage-gated potassium channel complex autoimmunity in primary PNH pathogenesis. Then again, a long list of toxic compounds and genetic factors has also been implicated in development of PNH. The management of primary PNH syndromes comprises symptomatic treatment with anticonvulsant drugs, immune modulation if necessary, and treatment of possible associated dysimmune and/or malignant conditions. PMID:25719304

  11. Vitamin D deficiency leads to sensory and sympathetic denervation of the rat synovium

    PubMed Central

    Tague, Sarah E.; Smith, Peter G.

    2014-01-01

    Vitamin D deficiency is associated with increased susceptibility to inflammatory arthritis. Sensory and sympathetic synovial nerves are critical to the development of inflammatory arthritis and spontaneously degenerate in the early phases of disease. These nerves contain vitamin D receptors and vitamin D influences nerve growth and neurotrophin expression. We therefore examined the density of synovial nerves and neurotrophin-containing cells in vitamin D deficient rats. Seven week old Sprague Dawley rats were fed either control or vitamin D deficient diets for four weeks. Knee synovium sections extending from patella to meniscus were immunostained for total nerves, myelinated and unmyelinated nerves, sympathetic nerves, peptidergic and non-peptidergic sensory nerves, and neurotrophins and immune cell markers. In control rats, intimal innervation by unmyelinated sensory fibers was denser than subintimal innervation. In contrast, sympathetic innervation was confined to the subintima. Many sensory axons contained markers for both peptidergic and non-peptidergic nerves. NGF was primarily expressed by intimal CD163-negative type B synoviocytes, while neurturin, a ligand selective for non-peptidergic sensory neurons, was expressed by synovial mast cells. In vitamin D deficient rats, there were significant reductions in sensory nerves in the intima and sympathetic nerves in the subintima. While there was no significant change in NGF-immunoreactivity, the number of neurturin-expressing mast cells was significantly reduced in the intima, suggesting that intimal reductions in sensory nerves may be related to reductions in neurturin. Vitamin D deficiency therefore may increase susceptibility to inflammatory arthritis by depleting sensory and sympathetic synovial nerves as a result of reduced synovial neurotrophin content. PMID:25193239

  12. Nanofibrous nerve conduit-enhanced peripheral nerve regeneration.

    PubMed

    Jiang, Xu; Mi, Ruifa; Hoke, Ahmet; Chew, Sing Yian

    2014-05-01

    Fibre structures represent a potential class of materials for the formation of synthetic nerve conduits due to their biomimicking architecture. Although the advantages of fibres in enhancing nerve regeneration have been demonstrated, in vivo evaluation of fibre size effect on nerve regeneration remains limited. In this study, we analyzed the effects of fibre diameter of electrospun conduits on peripheral nerve regeneration across a 15-mm critical defect gap in a rat sciatic nerve injury model. By using an electrospinning technique, fibrous conduits comprised of aligned electrospun poly (?-caprolactone) (PCL) microfibers (981?±?83 nm, Microfiber) or nanofibers (251?±?32 nm, Nanofiber) were obtained. At three months post implantation, axons regenerated across the defect gap in all animals that received fibrous conduits. In contrast, complete nerve regeneration was not observed in the control group that received empty, non-porous PCL film conduits (Film). Nanofiber conduits resulted in significantly higher total number of myelinated axons and thicker myelin sheaths compared to Microfiber and Film conduits. Retrograde labeling revealed a significant increase in number of regenerated dorsal root ganglion sensory neurons in the presence of Nanofiber conduits (1.93 ± 0.71 × 10(3) vs. 0.98 ± 0.30 × 10(3) in Microfiber, p?nerve regeneration. These results could provide useful insights for future nerve guide designs. PMID:22700359

  13. Children's exposure to violent video games and desensitization to violence.

    PubMed

    Funk, Jeanne B

    2005-07-01

    Desensitization to violence is cited frequently as being an outcome of exposure to media violence and a condition that contributes to increased aggression. This article initiates the development of a conceptual model for describing possible relationships among violent video games, brain function, and desensitization by using empathy and attitudes toward violence as proxy measures of desensitization. More work is needed to understand how specific game content may affect brain activity, how brain development may be affected by heavy play at young ages, and how personality and lifestyle variables may moderate game influence. Given the current state of knowledge, recommendations are made for clinicians to help parents monitor and limit exposure to violent video games and encourage critical thinking about media violence. PMID:15936665

  14. Optic Nerve Drusen

    MedlinePLUS

    ... Conditions Frequently Asked Questions Espańol Condiciones Chinese Conditions Optic Nerve Drusen En Espańol Read in Chinese What are optic nerve drusen? Optic nerve drusen are abnormal globular ...

  15. Communications Between the Trigeminal Nerve and the Facial Nerve in the Face: A Systematic Review.

    PubMed

    Hwang, Kun; Yang, Su Cheol; Song, Ju Sung

    2015-07-01

    The aim of the article is to elucidate the communications between the trigeminal nerve and facial nerve in the face. In a PubMed search, 328 studies were found using the terms 'trigeminal nerve, facial nerve, and communication.' The abstracts were read and 39 full-text articles were reviewed. Among them, 11 articles were analyzed. In the studies using dissection, the maxillary branch (V2) had the highest frequency (95.0%?±?8.0%) of communication with the facial nerve, followed by the mandibular branch (V3) (76.7%?±?38.5%). The ophthalmic branch (V1) had the lowest frequency of communication (33.8%?±?19.5%). In a Sihler stain, all of the maxillary branches and mandibular branches had communications with the facial nerve and 85.7% (12/14 hemifaces) of the ophthalmic branches had communications. The frequency of communications between the trigeminal nerve and facial nerve were significantly higher (P?=?0.00, t-test) in the studies using a Sihler stain (94.7%?±?1.1%) than the studies using dissection (76.9?±?35.8). The reason for the significantly higher frequency of trigeminal-facial communication in the studies using a Sihler stain is because of the limitation of the Sihler stain itself. This technique cannot differentiate the motor nerves from sensory nerves at the periphery, and a crossover can be misinterpreted as communication near to nerve terminal. PMID:26114519

  16. Damage to sensory fibers in a martin-gruber anomaly after biceps tendon repair.

    PubMed

    Riechers, Ronald G; Landau, Mark E; Farber, Gerald; Campbell, William W

    2005-06-01

    A patient with a distal biceps tendon rupture developed ulnar distribution sensory loss after surgical repair using the modified two-incision Boyd and Anderson technique. Electrodiagnosis demonstrated an absent ulnar sensory response but no clinical or electrodiagnostic evidence of ulnar neuropathy at the elbow. Nerve conduction studies demonstrated an anastomosis between the median and ulnar nerves (Martin-Gruber anomaly). Ulnar sensory fibers were probably damaged as they coursed with the median nerve at the elbow as a component of the innervation anomaly. This case documents the presence of ulnar sensory fibers as part of a Martin-Gruber anomaly. PMID:19078769

  17. Inhibitory action of endomorphin-1 on sensory neuropeptide release and neurogenic inflammation in rats and mice.

    PubMed

    Börzsei, R; Pozsgai, G; Bagoly, T; Elekes, K; Pintér, E; Szolcsányi, J; Helyes, Z

    2008-03-01

    Substance P (SP) and calcitonin gene-related peptide (CGRP) released from capsaicin-sensitive sensory nerves induce local neurogenic inflammation in the innervated area. The aim of the present study was to investigate the effects of an endogenous opioid peptide, endomorphin-1, on sensory neuropeptide release in vitro and acute neurogenic and non-neurogenic inflammatory reactions in vivo. Electrical field stimulation (EFS; 40 V, 0.1 ms, 10 Hz, 120 s; 1200 impulses) was performed to evoke SP and CGRP release from peptidergic afferents of the isolated rat tracheae which was determined from the incubation medium with radioimmunoassay. Neurogenic inflammation in the skin of the acutely denervated rat hind paw was induced by topical application of 1% mustard oil and detected by Evans Blue leakage. Mustard oil-induced ear swelling of the mouse was determined with a micrometer during 3 h and myeloperoxidase activity as an indicator of granulocyte accumulation was measured with spectrophotometry at 6 h. EFS evoked about a twofold elevation in the release of both pro-inflammatory sensory neuropeptides. Endomorphin-1 (5 nM-2 microM) diminished the release of SP and CGRP in a concentration-dependent manner, the EC50 values were 39.45 nM and 10.84 nM, respectively. The maximal inhibitory action was about 80% in both cases. Administration of endomorphin-1 (1-100 microg/kg i.p.) dose-dependently inhibited mustard oil-evoked neurogenic plasma protein extravasation in the rat skin as determined by microg Evans Blue per g wet tissue. Repeated i.p. injections of the 10 microg/kg dose three times per day for 10 days did not induce desensitization in this model. Neurogenic swelling of the mouse ear was also dose-dependently diminished by 1-100 microg/kg i.p. endomorphin-1, but non-neurogenic neutrophil accumulation was not influenced. These results suggest that endomorphin-1 is able to inhibit the outflow of pro-inflammatory sensory neuropeptides. Based on this mechanism of action it is also able to effectively diminish neurogenic inflammatory responses in vivo. PMID:18248905

  18. Opioid receptor desensitization: mechanisms and its link to tolerance

    PubMed Central

    Allouche, Stéphane; Noble, Florence; Marie, Nicolas

    2014-01-01

    Opioid receptors (OR) are part of the class A of G-protein coupled receptors and the target of the opiates, the most powerful analgesic molecules used in clinic. During a protracted use, a tolerance to analgesic effect develops resulting in a reduction of the effectiveness. So understanding mechanisms of tolerance is a great challenge and may help to find new strategies to tackle this side effect. This review will summarize receptor-related mechanisms that could underlie tolerance especially receptor desensitization. We will focus on the latest data obtained on molecular mechanisms involved in opioid receptor desensitization: phosphorylation, receptor uncoupling, internalization, and post-endocytic fate of the receptor. PMID:25566076

  19. Ulnar nerve sonography in leprosy neuropathy.

    PubMed

    Wang, Zhu; Liu, Da-Yue; Lei, Yang-Yang; Yang, Zheng; Wang, Wei

    2016-01-01

    A 23-year-old woman presented with a half-year history of right forearm sensory and motor dysfunction. Ultrasound imaging revealed definite thickening of the right ulnar nerve trunk and inner epineurium, along with heterogeneous hypoechogenicity and unclear nerve fiber bundle. Color Doppler exhibited a rich blood supply, which was clearly different from the normal ulnar nerve presentation with a scarce blood supply. The patient subsequently underwent needle aspiration of the right ulnar nerve, and histopathological examination confirmed that granulomatous nodules had formed with a large number of infiltrating lymphocytes and a plurality of epithelioid cells in the fibrous connective tissues, with visible atypical foam cells and proliferous vascularization, consistent with leprosy. Our report will familiarize readers with the characteristic sonographic features of the ulnar nerve in leprosy, particularly because of the decreasing incidence of leprosy in recent years. PMID:26703181

  20. A bioengineered peripheral nerve construct using aligned peptide amphiphile nanofibers

    PubMed Central

    Yalom, Anisa; Berns, Eric J.; Stephanopoulos, Nicholas; McClendon, Mark T.; Segovia, Luis A.; Spigelman, Igor; Stupp, Samuel I.; Jarrahy, Reza

    2014-01-01

    Peripheral nerve injuries can result in lifelong disability. Primary coaptation is the treatment of choice when the gap between transected nerve ends is short. Long nerve gaps seen in more complex injuries often require autologous nerve grafts or nerve conduits implemented into the repair. Nerve grafts, however, cause morbidity and functional loss at donor sites, which are limited in number. Nerve conduits, in turn, lack an internal scaffold to support and guide axonal regeneration, resulting in decreased efficacy over longer nerve gap lengths. By comparison, peptide amphiphiles (PAs) are molecules that can self-assemble into nanofibers, which can be aligned to mimic the native architecture of peripheral nerve. As such, they represent a potential substrate for use in a bioengineered nerve graft substitute. To examine this, we cultured Schwann cells with bioactive PAs (RGDS-PA, IKVAV-PA) to determine their ability to attach to and proliferate within the biomaterial. Next, we devised a PA construct for use in a peripheral nerve critical sized defect model. Rat sciatic nerve defects were created and reconstructed with autologous nerve, PLGA conduits filled with various forms of aligned PAs, or left unrepaired. Motor and sensory recovery were determined and compared among groups. Our results demonstrate that Schwann cells are able to adhere to and proliferate in aligned PA gels, with greater efficacy in bioactive PAs compared to the backbone-PA alone. In vivo testing revealed recovery of motor and sensory function in animals treated with conduit/PA constructs comparable to animals treated with autologous nerve grafts. Functional recovery in conduit/PA and autologous graft groups was significantly faster than in animals treated with empty PLGA conduits. Histological examinations also demonstrated increased axonal and Schwann cell regeneration within the reconstructed nerve gap in animals treated with conduit/PA constructs. These results indicate that PA nanofibers may represent a promising biomaterial for use in bioengineered peripheral nerve repair. PMID:25064803

  1. The re-formation of connections in the nervous sytem of Lymnaea stagnalis after nerve injury.

    PubMed

    Janse, C; Kits, K S; Lever, A J

    1979-01-01

    Changes in the tentacle reflex pathway of the pond snail Lymnaea stagnalis induced by peripheral nerve injury were studied with behavioural and electrophysiological techniques. After nerve injury regeneration of sensory axons is obtained in 6-12 days, suggesting an axonal outgrowth at a rate of 1 mm per day. Recovery of the tentacle reflex takes much more time indicating that synaptic efficacy is affected considerably by the period of sensory deprivation following nerve injury. PMID:226810

  2. Raman microspectroscopy for visualization of peripheral nerves

    NASA Astrophysics Data System (ADS)

    Minamikawa, Takeo; Harada, Yoshinori; Koizumi, Noriaki; Takamatsu, Tetsuro

    2013-02-01

    The peripheral nervous system plays an important role in motility, sensory, and autonomic functions of the human body. Preservation of peripheral nerves in surgery is essential for improving quality of life of patients. To preserve peripheral nerves, detection of ne peripheral nerves that cannot be identi ed by human eye or under white light imaging is necessary. In this study, we sought to provide a proof-of-principle demonstration of a label-free detection technique of peripheral nerve tissues against adjacent tissues that employs spontaneous Raman microspectroscopy. A line-illumination confocal Raman microscope was used for the experiment. A laser operating at the wavelength of 532 nm was used as an excitation laser light. We obtained Raman spectra of peripheral nerve, brous connective tissue, skeletal muscle, blood vessel, and adipose tissue of Wistar rats, and extracted speci c spectral features of peripheral nerves and adjacent tissues. By applying multivariate image analysis, peripheral nerves were clearly detected against adjacent tissues without any preprocessing neither xation nor staining. These results suggest the potential of the Raman spectroscopic observation for noninvasive and label-free nerve detection, and we expect this method could be a key technique for nerve-sparing surgery.

  3. Peripheral Nerve Disorders

    MedlinePLUS

    ... spinal cord. Like static on a telephone line, peripheral nerve disorders distort or interrupt the messages between the brain ... body. There are more than 100 kinds of peripheral nerve disorders. They can affect one nerve or many nerves. ...

  4. Nerve conduction velocity

    MedlinePLUS

    ... damage to the long portion of the nerve cell) Conduction block (the impulse is blocked somewhere along the nerve pathway) Demyelination (damage and loss of the fatty insulation surrounding the nerve cell) The nerve damage or destruction may be due ...

  5. Medial Plantar Nerve Entrapment

    MedlinePLUS

    ... Fibromatosis Medial and lateral plantar nerve entrapment is compression of nerve branches at the inner heel (the ... nerve or surgery to free the nerve from compression may help relieve pain. Foot Problems Overview of ...

  6. Eye Movement Desensitization and Reprocessing: A Critical Analysis.

    ERIC Educational Resources Information Center

    Erwin, Terry McVannel

    Since Shapiro's introduction of Eye Movement Desensitization and Reprocessing (EMDR) in 1989, it has been a highly controversial therapeutic technique. Critical reviews of Shapiro's initial study have highlighted many methodological shortcomings in her work. And early empirical research that followed Shapiro's original study has been criticized…

  7. Effects of Systematic Desensitization in the Alleviation of Communication Apprehension.

    ERIC Educational Resources Information Center

    Watson, Arden K.

    A study examined stages and objectives of a systematic desensitization (SD) program and its effects on subject reported apprehension levels and perceived benefits and behavior changes toward public speaking. Subjects, 19 freshmen and sophomore university students, were administered the Personal Report of Communication Apprehension-24 (PRCA-24).…

  8. Novel Roles for Osteopontin and Clusterin in Peripheral Motor and Sensory Axon Regeneration

    PubMed Central

    Mi, Ruifa; Connor, Emmalynn; Reed, Nicole; Vyas, Alka; Alspalter, Manula; Coppola, Giovanni; Geschwind, Daniel H.; Brushart, Thomas M.

    2014-01-01

    Previous studies demonstrated that Schwann cells (SCs) express distinct motor and sensory phenotypes, which impact the ability of these pathways to selectively support regenerating neurons. In the present study, unbiased microarray analysis was used to examine differential gene expression in denervated motor and sensory pathways in rats. Several genes that were significantly upregulated in either denervated sensory or motor pathways were identified and two secreted factors were selected for further analysis: osteopontin (OPN) and clusterin (CLU) which were upregulated in denervated motor and sensory pathways, respectively. Sciatic nerve transection induced upregulation of OPN and CLU and expression of both returned to baseline levels with ensuing regeneration. In vitro analysis using exogenously applied OPN induced outgrowth of motor but not sensory neurons. CLU, however, induced outgrowth of sensory neurons, but not motor neurons. To assess the functional importance of OPN and CLU, peripheral nerve regeneration was examined in OPN and CLU?/? mice. When compared with OPN+/+ mice, motor neuron regeneration was reduced in OPN?/? mice. Impaired regeneration through OPN?/? peripheral nerves grafted into OPN+/+ mice indicated that loss of OPN in SCs was responsible for reduced motor regeneration. Sensory neuron regeneration was impaired in CLU?/? mice following sciatic nerve crush and impaired regeneration nerve fibers through CLU?/? nerve grafts transplanted into CLU+/+ mice indicated that reduced sensory regeneration is likely due to SC-derived CLU. Together, these studies suggest unique roles for SC-derived OPN and CLU in regeneration of peripheral motor and sensory axons. PMID:24478351

  9. Sensory Dysfunction

    MedlinePLUS

    ... to Web version Sensory Dysfunction Overview Why are smell and taste important? Your senses of smell and taste let you fully enjoy the scents ... bitter and sour. Flavor involves both taste and smell. For example, because a person is able to ...

  10. A reversible functional sensory neuropathy model.

    PubMed

    Danigo, Aurore; Magy, Laurent; Richard, Laurence; Sturtz, Franck; Funalot, Benoît; Demiot, Claire

    2014-06-13

    Small-fiber neuropathy was induced in young adult mice by intraperitoneal injection of resiniferatoxin (RTX), a TRPV1 agonist. At day 7, RTX induced significant thermal and mechanical hypoalgesia. At day 28, mechanical and thermal nociception were restored. No nerve degeneration in skin was observed and unmyelinated nerve fiber morphology and density in sciatic nerve were unchanged. At day 7, substance P (SP) was largely depleted in dorsal root ganglia (DRG) neurons, although calcitonin gene-related peptide (CGRP) was only moderately depleted. Three weeks after, SP and CGRP expression was restored in DRG neurons. At the same time, CGRP expression remained low in intraepidermal nerve fibers (IENFs) whereas SP expression had improved. In summary, RTX induced in our model a transient neuropeptide depletion in sensory neurons without nerve degeneration. We think this model is valuable as it brings the opportunity to study functional nerve changes in the very early phase of small fiber neuropathy. Moreover, it may represent a useful tool to study the mechanisms of action of therapeutic strategies to prevent sensory neuropathy of various origins. PMID:24792390

  11. Inferior alveolar nerve injury following orthognathic surgery: a review of assessment issues

    PubMed Central

    PHILLIPS, C.; ESSICK, G.

    2011-01-01

    SUMMARY The sensory branches of the trigeminal nerve encode information about facial expressions, speaking and chewing movements, and stimuli that come into contact with the orofacial tissues. Whatever the cause, damage to the inferior alveolar nerve negatively affects the quality of facial sensibility as well as the patient's ability to translate patterns of altered nerve activity into functionally meaningful motor behaviours. There is no generally accepted, standard method of estimating sensory disturbances in the distribution of the inferior alveolar nerve following injury. Assessment of sensory alterations can be conducted using three types of measures: (i) objective electrophysiological measures of nerve conduction, (ii) sensory testing (stimulus) measures and (iii) patient report. Each type of measure with advantages and disadvantages for use are reviewed. PMID:21058973

  12. Role of domain calcium in purinergic P2X2 receptor channel desensitization.

    PubMed

    Coddou, Claudio; Yan, Zonghe; Stojilkovic, Stanko S

    2015-05-01

    Activation of P2X2 receptor channels (P2X2Rs) is characterized by a rapid current growth accompanied by a decay of current during sustained ATP application, a phenomenon known as receptor desensitization. Using rat, mouse, and human receptors, we show here that two processes contribute to receptor desensitization: bath calcium-independent desensitization and calcium-dependent desensitization. Calcium-independent desensitization is minor and comparable during repetitive agonist application in cells expressing the full size of the receptor but is pronounced in cells expressing shorter versions of receptors, indicating a role of the COOH terminus in control of receptor desensitization. Calcium-dependent desensitization is substantial during initial agonist application and progressively increases during repetitive agonist application in bath ATP and calcium concentration-dependent manners. Experiments with substitution of bath Na(+) with N-methyl-d-glucamine (NMDG(+)), a large organic cation, indicate that receptor pore dilation is a calcium-independent process in contrast to receptor desensitization. A decrease in the driving force for calcium by changing the holding potential from -60 to +120 mV further indicates that calcium influx through the channel pores at least partially accounts for receptor desensitization. Experiments with various receptor chimeras also indicate that the transmembrane and/or intracellular domains of P2X2R are required for development of calcium-dependent desensitization and that a decrease in the amplitude of current slows receptor desensitization. Simultaneous calcium and current recording shows development of calcium-dependent desensitization without an increase in global intracellular calcium concentrations. Combined with experiments with clamping intrapipette concentrations of calcium at various levels, these experiments indicate that domain calcium is sufficient to establish calcium-dependent receptor desensitization in experiments with whole-cell recordings. PMID:25673774

  13. Adult Peripheral Nerve Disorders—Nerve Entrapment, Repair, Transfer and Brachial Plexus Disorders

    PubMed Central

    Fox, Ida K.; Mackinnon, Susan E.

    2011-01-01

    Learning Objectives After reviewing this article the reader should be able to: 1. Describe the pathophysiologic bases for nerve injury and how it applies to patient evaluation and management. 2. Realize the wide variety of injury patterns and associated patient complaint and physical findings associated with peripheral nerve pathology. 3. Evaluate and recommend further tests to aid in defining the diagnosis. 4. Specify treatment options and potential risks and benefits. Summary Peripheral nerve disorders comprise a gamut of problems ranging from entrapment neuropathy, to direct open traumatic injury and closed brachial plexus injury. The pathophysiology of injury defines the patient symptoms, exam findings and treatment options and is critical to accurate diagnosis and treatment. Goals of treatment include management of often associated pain and improvement of sensory and motor function. Understanding peripheral nerve anatomy is critical to adopting novel nerve transfer procedures, which may provide superior options for a variety of injury patterns. PMID:21532404

  14. A novel internal fixator device for peripheral nerve regeneration.

    PubMed

    Chuang, Ting-Hsien; Wilson, Robin E; Love, James M; Fisher, John P; Shah, Sameer B

    2013-06-01

    Recovery from peripheral nerve damage, especially for a transected nerve, is rarely complete, resulting in impaired motor function, sensory loss, and chronic pain with inappropriate autonomic responses that seriously impair quality of life. In consequence, strategies for enhancing peripheral nerve repair are of high clinical importance. Tension is a key determinant of neuronal growth and function. In vitro and in vivo experiments have shown that moderate levels of imposed tension (strain) can encourage axonal outgrowth; however, few strategies of peripheral nerve repair emphasize the mechanical environment of the injured nerve. Toward the development of more effective nerve regeneration strategies, we demonstrate the design, fabrication, and implementation of a novel, modular nerve-lengthening device, which allows the imposition of moderate tensile loads in parallel with existing scaffold-based tissue engineering strategies for nerve repair. This concept would enable nerve regeneration in two superposed regimes of nerve extension--traditional extension through axonal outgrowth into a scaffold and extension in intact regions of the proximal nerve, such as that occurring during growth or limb-lengthening. Self-sizing silicone nerve cuffs were fabricated to grip nerve stumps without slippage, and nerves were deformed by actuating a telescoping internal fixator. Poly(lactic co-glycolic) acid (PLGA) constructs mounted on the telescoping rods were apposed to the nerve stumps to guide axonal outgrowth. Neuronal cells were exposed to PLGA using direct contact and extract methods, and they exhibited no signs of cytotoxic effects in terms of cell morphology and viability. We confirmed the feasibility of implanting and actuating our device within a sciatic nerve gap and observed axonal outgrowth following device implantation. The successful fabrication and implementation of our device provides a novel method for examining mechanical influences on nerve regeneration. PMID:23102114

  15. Rare communication between the musculocutaneous and median nerves in the forearm: its clinical significance.

    PubMed

    Liu, Hong-Fu; Won, Hyung-Sun; Chung, In-Hyuk; Kim, Seung-Min; Kim, In-Beom

    2014-10-01

    Morphologic classifications of communication between musculocutaneous and median nerves are not based on the distribution and the function of the communicating branch. The authors report a rare case of such a communication with passage of the median nerve through the pronator teres muscle and discuss its clinical significance. The musculocutaneous nerve was divided into a lateral branch that continued to the lateral antebrachial cutaneous nerve and a medial branch that joined the median nerve in the forearm. The authors separated the nerve bundles and noted that the communicating branch derived from the sixth to seventh cervical nerves and supplied nerve fibers to the pronator teres muscle and the proper palmar digital nerve of the thumb. In addition, the median nerve penetrated the humeral head of the pronator teres muscle. Isolated musculocutaneous neuropathy with such a communication may cause unexpected symptoms such as sensory deficit in the palm and muscular weakness of the forearm and the thumb. PMID:25122101

  16. Expression of leukemia inhibitory factor in human nerve following injury.

    PubMed

    Dowsing, B J; Romeo, R; Morrison, W A

    2001-11-01

    In animal models of peripheral nerve injury, leukemia inhibitory factor (LIF) is normally expressed at very low levels. Following nerve injury, its expression is rapidly increased in the nerve at the injury site and promotes both sensory and motor neuron survival. Once normal nerve function is restored, LIF expression returns to negligible levels. For this reason, LIF is considered to be a peripheral nerve trauma factor. We wished to determine whether LIF is also upregulated in human nerves following trauma and whether it is expressed in neuromas of varying age. Immunohistochemical staining for the presence of LIF was performed on injured and control human nerves from a number of subjects. Results demonstrate that LIF expression is increased in nerves within hours of injury and, in the case of neuroma formation, can persist for several years. LIF immunoreactivity was consistently found in Schwann cells, in peripheral nerve axons, and, at stages when an inflammatory response was present, also in neutrophils, mast cells, macrophages, and blood vessel walls. The level of staining within the connective tissue of injured nerves was elevated compared to control nerves, which may be due to the presence of LIF bound to the soluble secreted form of the LIF receptor. Whether the continued expression of LIF is unhealed injured nerves promotes the development of neuromas remains to be resolved. PMID:11721746

  17. The Proximal Medial Sural Nerve Biopsy Model: A Standardised and Reproducible Baseline Clinical Model for the Translational Evaluation of Bioengineered Nerve Guides

    PubMed Central

    van Neerven, Sabien G. A.; Claeys, Kristl G.; O'Dey, Dan mon; Brook, Gary A.; Sellhaus, Bernd; Schulz, Jörg B.; Weis, Joachim; Pallua, Norbert

    2014-01-01

    Autologous nerve transplantation (ANT) is the clinical gold standard for the reconstruction of peripheral nerve defects. A large number of bioengineered nerve guides have been tested under laboratory conditions as an alternative to the ANT. The step from experimental studies to the implementation of the device in the clinical setting is often substantial and the outcome is unpredictable. This is mainly linked to the heterogeneity of clinical peripheral nerve injuries, which is very different from standardized animal studies. In search of a reproducible human model for the implantation of bioengineered nerve guides, we propose the reconstruction of sural nerve defects after routine nerve biopsy as a first or baseline study. Our concept uses the medial sural nerve of patients undergoing diagnostic nerve biopsy (?2?cm). The biopsy-induced nerve gap was immediately reconstructed by implantation of the novel microstructured nerve guide, Neuromaix, as part of an ongoing first-in-human study. Here we present (i) a detailed list of inclusion and exclusion criteria, (ii) a detailed description of the surgical procedure, and (iii) a follow-up concept with multimodal sensory evaluation techniques. The proximal medial sural nerve biopsy model can serve as a preliminarynature of the injuries or baseline nerve lesion model. In a subsequent step, newly developed nerve guides could be tested in more unpredictable and challenging clinical peripheral nerve lesions (e.g., following trauma) which have reduced comparability due to the different nature of the injuries (e.g., site of injury and length of nerve gap). PMID:25006574

  18. Correlation of measurements of pressure perception using the pressure-specified sensory device with electrodiagnostic testing.

    PubMed

    Tassler, P L; Dellon, A L

    1995-07-01

    Quantitative sensory testing of pressure threshold has been recommended for diagnosis and monitoring of peripheral nerve problems, yet there has been no validation of the results of such testing with electrodiagnostic testing (EDT), the "gold standard." The Pressure-Specified Sensory Device (PSSD) was used to measure the pressure threshold in 72 clinical nerve entrapment syndromes (23 carpal, 23 cubital, and 16 tarsal tunnel syndromes, and 10 common peroneal nerve entrapment at the fibular head), each of which also had EDT. There was diagnostic agreement between both EDT and PSSD in 54 of the 72 nerve entrapments (75%). The sensitivity of the PSSD was 100% for each of the four nerve entrapments. In those patients in whom there was a disagreement, the PSSD was abnormal when the EDT was normal. In conclusion, quantitative sensory testing with the PSSD has a high sensitivity, but a low specificity, when compared with EDT for diagnosis of peripheral nerve entrapment. PMID:7552472

  19. Neuromodulation of the suprascapular nerve.

    PubMed

    Elahi, Foad; Reddy, Chandan G

    2014-01-01

    The shoulder joint is an enarthrodial or ball-and-socket joint. A complex network of anatomic structures endows the human shoulder with tremendous mobility, greater than any other joint in the body. Many pathologies can been found in those patients with chronic shoulder pain. The painful limitation of shoulder motion affects hand and arm motion as well; therefore, it significantly influences work performance and everyday activities as well as the quality of life. Therefore, the treatment of patients with chronic shoulder pain has major social and health economic implications. In this article we present a patient with a complex history of shoulder pathology including 7 surgeries that left the patient with chronic debilitating shoulder pain. She was suffering from chronic pain and limited mobility of the shoulder joint due to adhesive shoulder capsulitis. She was treated with a multimodality approach with the goals of increasing shoulder range of motion and decreasing her pain. This did not provide significant improvement. The suprascapular nerve supplies motor and sensory innervation to the shoulder, and can be easily accessible in the supraspinatus fossa. A suprascapular nerve block dramatically decreased her pain. This clinical observation along with confirmatory nerve block play an important role during the decision-making process for a trial period of electrical neuromodulation. She was followed for 3 months after the permanent implantation of a suprascapular nerve stimulator. Her pain and shoulder range of motion in all planes improved dramatically. Peripheral nerve stimulation (PNS) of the suprascapular nerve, in addition to multimodality pain management, is one approach to the difficult task of treating adhesive capsulitis with accompanying pain and the inability to move the shoulder. We conducted a literature review on PubMed and found no case describing a similar patient to our knowledge. PMID:25415792

  20. Brentuximab vedotin desensitization in a patient with refractory Hodgkin's lymphoma.

    PubMed

    Arora, Anubha; Bhatt, Vijaya Raj; Liewer, Susanne; Armitage, James O; Bociek, R Gregory

    2015-10-01

    Brentuximab vedotin has emerged as a useful treatment option for relapsed or refractory Hodgkin's lymphoma; however, uncommon cases of anaphylactic reactions may require its permanent discontinuation. We report a 29-yr-old woman with refractory Hodgkin's lymphoma, who developed an anaphylactic reaction during the second dose of brentuximab vedotin. A 12-step desensitization protocol was followed; after premedicating with antihistaminic agents, methylprednisolone and montelukast, a total dose of 156 mg of brentuximab vedotin (1.8 mg/kg) was given as three infusions with increasing rate and concentration. Such desensitization protocol can allow safe administration of brentuximab vedotin and may have a broader applicability in managing hypersensitivity reactions with other monoclonal antibodies. PMID:25892213

  1. Sensory PhenotypesSensory Phenotypes 1st ISBS Summer School1st ISBS Summer School

    E-print Network

    Kalueff, Allan V.

    ­ creates appearance of low anxiety · alternatively, use hole-poke or 2 lever test Learning and memory · Triggers nerves that send messages to the brain · Used for sensory inputs Ratbehavior.org #12 conditioning. Measures learning and memory of a specific auditory stimulus -Can use contextual test instead

  2. Ultrasound imaging accurately identifies the intercostobrachial nerve

    PubMed Central

    Thallaj, Ahmed K.; Harbi, Mohammad K. Al; Alzahrani, Tariq A.; El-Tallawy, Salah N.; Alsaif, Abdulaziz A.; Alnajjar, Mohannad

    2015-01-01

    Objectives: To test the hypothesis that identification and blockade of the intercostobrachial nerve (ICBN) can be achieved under ultrasound (US) guidance using a small volume of local anesthetic. Methods: Twenty-eight adult male volunteers were examined at King Khalid University Hospital, Riyadh, Kingdom of Saudi Arabia from November 2012 to September 2013. Intercostobrachial nerve blockade was performed using one ml of 2% lidocaine under US guidance. A sensory map of the blocked area was developed relative to the medial aspect of the humeral head. Results: The ICBN appears as a hyper-echoic structure. The nerve diameter was 2.3±0.28 mm, and the depth was 9±0.28 mm. The measurements of the sensory-blocked area relative to the medial aspect of the humeral head were as follows: 6.3±1.6 cm anteriorly; 6.2±2.9 cm posteriorly; 9.4±2.9 cm proximally; and 9.2±4.4 cm distally. Intercostobrachial nerve blockade using one ml of local anesthetic was successful in all cases. Conclusion: The present study described the sonographic anatomical details of the ICBN and its sensory distribution to successfully perform selective US-guided ICBN blockade. PMID:26446339

  3. Micromorphological Evaluation of Dentin Treated with Different Desensitizing Agents

    PubMed Central

    Osmari, Deise; de Oliveira Ferreira, Ana Carolina; de Carlo Bello, Mariana; Henrique Susin, Alexandre; Cecília Correa Aranha, Ana; Marquezan, Marcela; Lopes da Silveira, Bruno

    2013-01-01

    Introduction: The purpose of a desensitizing agent is a permanent coating or filling of dentin surface. Morphological analysis in vitro of this treated surface is essential to understand the interaction between desensitizing agent and hypersensitive dentin. The aim was to evaluate the morphology of four dentin surface treated with desensitizing agents. Methods: This was an in vitro laboratory study, where fifteen specimens from extracted human premolars were obtained. The enamel was removed to expose the dentin surface, polished with silicon carbide abrasive papers and etched with 6% citric acid for 2 min.The specimens were randomly divided into 5 groups: G1 - without treatment (control) (C), G2 - fluoride varnish (FV), G3 - potassium oxalate (PO), G4 - 2-step self-etching adhesive system (AS), G5 - diode laser (DL). The specimens were cleaved in the lingual buccaldirection, prepared for analysis by Scanning Electron Microscope and the surface and interior of the dentinal tubules were observed at 1500× magnification. Results: In the control group, the dentin etching promoted smear layer removal and exposure of dentinal tubules. In the group of fluoride varnish, a film was observed on the surface, with plugs of varnish into tubules. In the group of oxalate, partial obliteration of the tubular entrances was observed. In the group of the adhesive system, the tubules were obstructed through the formation of hybrid layer and a physical barrier on the surface. In the group of the diode laser, dentin melting and solidification with partial occlusion of dentinal tubules were observed. Conclusions: All desensitizing agents evaluated demonstrated ability to modify the surface of dentin, with partial or total occlusion of dentinal tubules. Thus, it is suggested to do more clinical studies to verify the effectiveness of the findings. PMID:25606322

  4. Explosives malfunction from sympathetic detonation to shock desensitization

    SciTech Connect

    Katsabanis, P.D.; Yeung, C.; Fitz, G.; Heater, R.

    1994-12-31

    Explosives malfunction due to shock waves is a serious concern for successful blasting results. Malfunction can range from sympathetic detonation to desensitization and modification of firing times of conventional pyrotechnic detonators. Decked charges consisting of commercial emulsion explosives having a detonator and a primer were placed in 10cm diameter blastholes and their performance was recorded. Due to the limited length of the holes the events were mainly sympathetic detonations although desensitization was also recorded. Pressure measurements along the stemming column showed that shock waves produced by an explosive have a significant amplitude even at relatively large distances away from the detonating explosive. It was found that 2m away from a detonating charge the pressures in the stemming material were above 0.1 GPa indicating that there is potential for primers and detonators to malfunction. Parallel charges consisting of a commercial emulsion explosive with a diameter of 32mm were confined in 2mm thick steel tubes and initiation was attempted using detonators having a delay interval of 25ms. The charges were placed in sand and the velocity of detonation of the acceptor charge was recorded using a continuous resistance probe system. Carbon resistors were also placed in the same position as the acceptor charge to examine the dynamic pressures that were applied to the charge. Sympathetic detonation, complete desensitization, partial desensitization and properly sequenced detonations were observed as the distance between charges was increased from 76 mm to 305 mm. Delay detonators were also tested in a similar to the last configuration. Modification of firing times was observed at distances between 150 and 360 mm.

  5. Median and ulnar nerve injuries; what causes different repair outcomes?

    PubMed Central

    Nouraei, Mohammad Hadi; Hosseini, Alireza; Salek, Shadi; Nouraei, Farhad; Bina, Roya

    2015-01-01

    Background: Peripheral nerve injuries have significant effects on patients’ life quality. To make patients’ therapeutic expectations more realistic, prediction of repair outcome has significant importance. Materials and Methods: Totally, 74 patients with 94 nerve injuries (44 median and 50 ulnar nerves) were evaluated and followed up for 5 years between 2008 and 2013 in two main university hospitals of Isfahan. Patients’ age was 6–64 years. 24 nerves were excluded from the study and among the remaining; 53 nerves were repaired primarily and 17 nerves secondarily. 42 nerves were injured at a low-level, 17 nerves at intermediate and 11 at a high one. Medical Research Council Scale used for sensory and motor assessment. S3+ and S4 scores for sensory recovery and M4 and M5 scores for motor recovery were considered as favorable results. The follow-up time was between 8 and 24 months. Results: There was no significant difference between favorable sensory outcomes of median and ulnar nerves. The difference between favorable motor outcomes of the median nerve was higher than ulnar nerve (P = 0.03, odds ratio = 2.9). More favorable results were seen in high-level injuries repair than low ones (P = 0.035), and also cases followed more than 18 months compared to less than 12 months (P = 0.041), respectively. The favorable outcomes for patients younger than 16 were more than 40 and older, however, their difference was not significant (P = 0.059). The difference between primary and secondary repair favorable outcomes was not significant (P = 0.37). Conclusion: In patients older than 40 or injured at a high-level, there is a high possibility of repetitive operations and reconstructive measures. The necessity for long-term follow-up and careful attentions during a postoperative period should be pointed to all patients. PMID:26605244

  6. [Acetylsalicylic acid desensitization in the new era of percutaneous coronary intervention].

    PubMed

    Fuertes Ferre, Georgina; Ferrer Gracia, Maria Cruz; Calvo Cebollero, Isabel

    2015-09-21

    Dual antiplatelet therapy is essential in patients undergoing percutaneous coronary intervention with stent implantation. Hypersensitivity to acetylsalicylic acid (ASA) limits treatment options. Desensitization to ASA has classically been studied in patients with respiratory tract disease. Over the last years, many protocols have been described about ASA desensitization in patients with ischemic heart disease, including acute coronary syndrome and the need for coronary stent implantation. It is important to know the efficacy and safety of ASA desensitization in these patients. PMID:25577589

  7. Surgical outcomes following nerve transfers in upper brachial plexus injuries

    PubMed Central

    Bhandari, P. S.; Sadhotra, L. P.; Bhargava, P.; Bath, A. S.; Mukherjee, M. K.; Bhatti, Tejinder; Maurya, Sanjay

    2009-01-01

    Background: Brachial plexus injuries represent devastating injuries with a poor prognosis. Neurolysis, nerve repair, nerve grafts, nerve transfer, functioning free-muscle transfer and pedicle muscle transfer are the main surgical procedures for treating these injuries. Among these, nerve transfer or neurotization is mainly indicated in root avulsion injury. Materials and Methods: We analysed the results of various neurotization techniques in 20 patients (age group 20-41 years, mean 25.7 years) in terms of denervation time, recovery time and functional results. The inclusion criteria for the study included irreparable injuries to the upper roots of brachial plexus (C5, C6 and C7 roots in various combinations), surgery within 10 months of injury and a minimum follow-up period of 18 months. The average denervation period was 4.2 months. Shoulder functions were restored by transfer of spinal accessory nerve to suprascapular nerve (19 patients), and phrenic nerve to suprascapular nerve (1 patient). In 11 patients, axillary nerve was also neurotized using different donors - radial nerve branch to the long head triceps (7 patients), intercostal nerves (2 patients), and phrenic nerve with nerve graft (2 patients). Elbow flexion was restored by transfer of ulnar nerve motor fascicle to the motor branch of biceps (4 patients), both ulnar and median nerve motor fascicles to the biceps and brachialis motor nerves (10 patients), spinal accessory nerve to musculocutaneous nerve with an intervening sural nerve graft (1 patient), intercostal nerves (3rd, 4th and 5th) to musculocutaneous nerve (4 patients) and phrenic nerve to musculocutaneous nerve with an intervening graft (1 patient). Results: Motor and sensory recovery was assessed according to Medical Research Council (MRC) Scoring system. In shoulder abduction, five patients scored M4 and three patients M3+. Fair results were obtained in remaining 12 patients. The achieved abduction averaged 95 degrees (range, 50 - 170 degrees). Eight patients scored M4 power in elbow flexion and assessed as excellent results. Good results (M3+) were obtained in seven patients. Five patients had fair results (M2+ to M3). PMID:20368849

  8. Comparison of measures of large-fiber nerve function in patients with chronic nerve compression and neuropathy.

    PubMed

    Radoiu, Horatio; Rosson, Gedge D; Andonian, Eugenia; Senatore, John; Dellon, A Lee

    2005-01-01

    Measurement of large-fiber peripheral nerve function is critical to the assessment of patients with nerve injury, chronic nerve compression, and neuropathy. We evaluated the Semmes-Weinstein nylon monofilament (SWM), vibrometry, and the Pressure-Specified Sensory Device (PSSD) (Sensory Management Services LLC, Baltimore, Maryland) prospectively on the plantar surface of the hallux, bilaterally, in 35 patients with peripheral nerve problems related to nerve compression and neuropathy. Five patients had carpal tunnel syndrome and, therefore, had normal hallux measurements. Normative data for the SWM were obtained for 59 age-stratified people. A moderately strong Pearson product moment correlation was found for large-fiber nerve function between the PSSD and the SWM and between the PSSD and vibrometry. However, when these functions were compared with normative values for each neurosensory testing technique, sensitivity for detecting the presence of a peripheral nerve problem was 100% for the PSSD, 63% for the SWM, and 30% for vibrometry. False-positive test results were obtained for the hallux in 0% of normal feet when the PSSD was used, in 20% when vibrometry was used, and in 30% when the SWM was used as the test instrument. The PSSD was the most sensitive in identifying the presence of a large-fiber peripheral nerve problem in patients with pain or paresthesia in the foot related to the posterior tibial nerve. PMID:16166460

  9. Positive allosteric modulators of AMPA receptors reduce proton-induced receptor desensitization in rat hippocampal neurons.

    PubMed

    Lei, S; Orser, B A; Thatcher, G R; Reynolds, J N; MacDonald, J F

    2001-05-01

    Whole-cell or outside-out patch recordings were used to investigate the effects of protons and positive modulators of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors on the desensitization of glutamate-evoked AMPA receptor currents in isolated hippocampal CA1 neurons. Protons inhibited glutamate-evoked currents (IC(50) of 6.2 pH units) but also enhanced the apparent rate and extent of AMPA receptor desensitization. The proton-induced enhancement of desensitization could not be attributed to a reduction in the rate of recovery from desensitization or to a change in the kinetics of deactivation. Non-stationary variance analysis indicated that protons reduced maximum open probability without changing the conductance of AMPA channels. The positive modulators of AMPA receptor desensitization, cyclothiazide and GT-21-005 (an organic nitrate), reduced the proton sensitivity of AMPA receptor desensitization, which suggests that they interact with protons to diminish desensitization. In contrast, the effects of wheat germ agglutinin and aniracetam on AMPA receptor desensitization were independent of pH. These results demonstrate that a reduction in the proton sensitivity of receptor desensitization contributes to the mechanism of action of some positive modulators of AMPA receptors. PMID:11353019

  10. Optic Nerve Pit

    MedlinePLUS

    ... Conditions Frequently Asked Questions Espańol Condiciones Chinese Conditions Optic Nerve Pit What is optic nerve pit? An optic nerve pit is a ... may be seen in both eyes. How is optic pit diagnosed? If the pit is not affecting ...

  11. Mechanisms of alpha 1-adrenergic vascular desensitization in conscious dogs

    NASA Technical Reports Server (NTRS)

    Kiuchi, K.; Vatner, D. E.; Uemura, N.; Bigaud, M.; Hasebe, N.; Hempel, D. M.; Graham, R. M.; Vatner, S. F.

    1992-01-01

    To investigate the mechanisms of alpha 1-adrenergic vascular desensitization, osmotic minipumps containing either saline (n = 9) or amidephrine mesylate (AMD) (n = 9), a selective alpha 1-adrenergic receptor agonist, were implanted subcutaneously in dogs with chronically implanted arterial and right atrial pressure catheters and aortic flow probes. After chronic alpha 1-adrenergic receptor stimulation, significant physiological desensitization to acute AMD challenges was observed, i.e., pressor and vasoconstrictor responses to the alpha 1-adrenergic agonist were significantly depressed (p < 0.01) compared with responses in the same dogs studied in the conscious state before pump implantation. However, physiological desensitization to acute challenges of the neurotransmitter norepinephrine (NE) (0.1 micrograms/kg per minute) in the presence of beta-adrenergic receptor blockade was not observed for either mean arterial pressure (MAP) (30 +/- 7 versus 28 +/- 5 mm Hg) or total peripheral resistance (TPR) (29.8 +/- 4.9 versus 28.9 +/- 7.3 mm Hg/l per minute). In the presence of beta-adrenergic receptor plus ganglionic blockade after AMD pump implantation, physiological desensitization to NE was unmasked since the control responses to NE (0.1 micrograms/kg per minute) before the AMD pumps were now greater (p < 0.01) than after chronic AMD administration for both MAP (66 +/- 5 versus 32 +/- 2 mm Hg) and TPR (42.6 +/- 10.3 versus 23.9 +/- 4.4 mm Hg/l per minute). In the presence of beta-adrenergic receptor, ganglionic, plus NE-uptake blockade after AMD pump implantation, desensitization was even more apparent, since NE (0.1 micrograms/kg per minute) induced even greater differences in MAP (33 +/- 5 versus 109 +/- 6 mm Hg) and TPR (28.1 +/- 1.8 versus 111.8 +/- 14.7 mm Hg/l per minute). The maximal force of contraction induced by NE in the presence or absence of endothelium was significantly decreased (p < 0.05) in vitro in mesenteric artery rings from AMD pump dogs compared with saline control dogs. Furthermore, alpha 1-adrenergic receptor density, as determined by [3H]prazosin binding in membrane preparations from vessels in the mesentery, was decreased (8.2 +/- 1.0 versus 18.4 +/- 1.4 fmol/mg protein, p < 0.001) without any change in Kd in the AMD pump dogs compared with the saline pump dogs.(ABSTRACT TRUNCATED AT 400 WORDS).

  12. Peripheral Nerve Reconstruction after Injury: A Review of Clinical and Experimental Therapies

    PubMed Central

    Grinsell, D.; Keating, C. P.

    2014-01-01

    Unlike other tissues in the body, peripheral nerve regeneration is slow and usually incomplete. Less than half of patients who undergo nerve repair after injury regain good to excellent motor or sensory function and current surgical techniques are similar to those described by Sunderland more than 60 years ago. Our increasing knowledge about nerve physiology and regeneration far outweighs our surgical abilities to reconstruct damaged nerves and successfully regenerate motor and sensory function. It is technically possible to reconstruct nerves at the fascicular level but not at the level of individual axons. Recent surgical options including nerve transfers demonstrate promise in improving outcomes for proximal nerve injuries and experimental molecular and bioengineering strategies are being developed to overcome biological roadblocks limiting patient recovery. PMID:25276813

  13. Nerve Impulses in Plants

    ERIC Educational Resources Information Center

    Blatt, F. J.

    1974-01-01

    Summarizes research done on the resting and action potential of nerve impulses, electrical excitation of nerve cells, electrical properties of Nitella, and temperature effects on action potential. (GS)

  14. Femoral nerve dysfunction

    MedlinePLUS

    Neuropathy - femoral nerve; Femoral neuropathy ... Felice, KJ. Focal neuropathies of the femoral, obturator, lateral femoral cutaneous and other nerves of the thigh and pelvis. In: Bromberg MB, Smith ...

  15. Sensoric Protection after Median Nerve Injury: Babysitter-Procedure Prevents Muscular Atrophy and Improves Neuronal Recovery

    PubMed Central

    Beck-Broichsitter, Benedicta E.; Becker, Stephan T.; Lamia, Androniki; Fregnan, Federica; Sinis, Nektarios

    2014-01-01

    The babysitter-procedure might offer an alternative when nerve reconstruction is delayed in order to overcome muscular atrophy due to denervation. In this study we aimed to show that a sensomotoric babysitter-procedure after median nerve injury is capable of preserving irreversible muscular atrophy. The median nerve of 20 female Wistar rats was denervated. 10 animals received a sensory protection with the N. cutaneous brachii. After six weeks the median nerve was reconstructed by autologous nerve grafting from the contralateral median nerve in the babysitter and the control groups. Grasping tests measured functional recovery over 15 weeks. At the end of the observation period the weight of the flexor digitorum sublimis muscle was determined. The median nerve was excised for histological examinations. Muscle weight (P < 0.0001) was significantly superior in the babysitter group compared to the control group at the end of the study. The histological evaluation revealed a significantly higher diameter of axons (P = 0.0194), nerve fiber (P = 0.0409), and nerve surface (P = 0.0184) in the babysitter group. We conclude that sensory protection of a motor nerve is capable of preserving muscule weight and we may presume that metabolism of the sensory nerve was sufficient to keep the target muscle's weight and vitality. PMID:25133176

  16. Use of Vein Conduit and Isolated Nerve Graft in Peripheral Nerve Repair: A Comparative Study

    PubMed Central

    Ahmad, Imran; Akhtar, Md. Sohaib

    2014-01-01

    Aims and Objectives. The aim of this study was to evaluate the effectiveness of vein conduit in nerve repair compared with isolated nerve graft. Materials and Methods. This retrospective study was conducted at author's centre and included a total of 40 patients. All the patients had nerve defect of more than 3?cm and underwent nerve repair using nerve graft from sural nerve. In 20 cases, vein conduit (study group) was used whereas no conduit was used in other 20 cases. Patients were followed up for 2 years at the intervals of 3 months. Results. Patients had varying degree of recovery. Sensations reached to all the digits at 1 year in study groups compared to 18 months in control group. At the end of second year, 84% patients of the study group achieved 2-point discrimination of <10?mm compared to 60% only in control group. In terms of motor recovery, 82% patients achieved satisfactory hand function in study group compared to 56% in control group (P < .05). Conclusions. It was concluded that the use of vein conduit in peripheral nerve repair is more effective method than isolated nerve graft providing good sensory and motor recovery. PMID:25405029

  17. Histochemical discrimination of fibers in regenerating rat infraorbital nerve

    NASA Technical Reports Server (NTRS)

    Wilke, R. A.; Riley, D. A.; Sanger, J. R.

    1992-01-01

    In rat dorsal root ganglia, histochemical staining of carbonic anhydrase (CA) and cholinesterase (CE) yields a reciprocal pattern of activity: Sensory processes are CA positive and CE negative, whereas motor processes are CA negative and CE positive. In rat infraorbital nerve (a sensory peripheral nerve), we saw extensive CA staining of nearly 100% of the myelinated axons. Although CE reactivity in myelinated axons was extremely rare, we did observe CE staining of unmyelinated autonomic fibers. Four weeks after transection of infraorbital nerves, CA-stained longitudinal sections of the proximal stump demonstrated 3 distinct morphological zones. A fraction of the viable axons retained CA activity to within 2 mm of the distal extent of the stump, and the stain is capable of resolving growth sprouts being regenerated from these fibers. Staining of unmyelinated autonomic fibers in serial sections shows that CE activity was not retained as far distally as is the CA sensory staining.

  18. Uncoupling of the beta-adrenergic receptor as a mechanism of in vitro neutrophil desensitization

    SciTech Connect

    Galant, S.P.; Britt, S.

    1984-02-01

    Human leukocytes have been useful in studying desensitization phenomena to beta-adrenergic agonists in a number of clinical conditions. In the present in vitro study the authors have explored the mechanism for beta-adrenergic desensitization and have compared conditions for homologous and heterologous desensitization, using the intact PMN model. PMN preincubated with isoproterenol (10/sup -4/M), washed thoroughly, then restimulated, desensitized rapidly so that within 10 min 80% of control isoproterenol-induced cyclic AMP stimulation is lost. Cells washed free of isoproterenol recover full responsiveness in 1 to 2 hr. The estimated isoproterenol desensitization EC/sub 50/ in cells washed and then restimulated is 1 x 10/sup -5/M, and EC/sub 50/ in unwashed cells that are restimulated is 9 x 10/sup -8/M. Rank-order potency studies of catecholamine desensitization show isoproterenol > epinephrine > norepinephrine, a beta-2 pattern. Isoproterenol-induced desensitization results in a small reduction in (/sup 3/H)DHA binding sites, which becomes statistically significant (p < 0.05) from control values at 1 hr (67% of control) and 3 hr (64%). In the absence of GTP, isoproterenol binding is characterized by an EC/sub 50/ of 6.6 +/- 2.6 x 10/sup -/(M, which is significantly different (p < 0.05) from the EC/sub 50/ of 38.1 +/- 9.1 x 10/sup -1/M found when cells are previously desensitized with isoproterenol for 10 min. GTP does not affect the EC/sub 50/ of desensitized cells. Finally, prolonged (3 hr) isoproterenol preincubation results in a small but significant (p < 0.05) loss of cyclic AMP responsiveness to histamine (67.7% +/- 11.7 of control) and PGE/sub 1/ (59.3% +/- 7.4), suggesting heterologous desensitization. These studies suggest that the human PMN is a suitable model to study both homologous and heterologous desensitization in vitro. 22 references. 6 figures. 3 tables.

  19. Nerve conduction studies in adrenomyeloneuropathy.

    PubMed Central

    Chaudhry, V; Moser, H W; Cornblath, D R

    1996-01-01

    OBJECTIVE--Adrenomyeloneuropathy (AMN) is an X linked metabolic disorder presenting with progressive spastic paraparesis in the third to fifth decade of life. Although peripheral neuropathy is also present in most patients, prominent pyramidal signs may make its clinical recognition difficult. The objective was to characterise the peripheral neuropathy in patients with AMN by nerve conduction studies. METHODS--Nerve conduction studies were performed in 99 men known to have AMN and in 38 heterozygous women, all of whom had neurological disabilities. RESULTS--Of the 13 variables obtained, at least one was abnormal in 82% of patients. The abnormalities were more common in men than in women (87% v 67%); in legs than in arms (77% v 38%); in motor than in sensory conduction (80% v 39%); and in latency (distal and F wave) and velocity compared with amplitude (80% v 29%). Twenty six patients had at least one nerve variable value in the demyelinating range. Four variables (sural velocity, peroneal amplitude, peroneal velocity, and peroneal F wave) were correlated with the expanded disability status scale; five variables (peroneal velocity, tibial H reflex, median distal latency, median conduction velocity, and median F wave latency) were correlated with serum very long chain fatty acids (VLCFAs); and two variables (sural amplitude and peroneal distal latency) were more likely to be abnormal in patients with normal adrenal function than in patients with Addison's disease. CONCLUSIONS--Nerve conduction studies in patients with AMN are often abnormal and suggest a mixture of axonal loss and multifocal demyelination. Their correlation with disability status and serum VLCFAs suggests that measures from nerve conduction studies may be useful in evaluating future treatments. Images PMID:8708687

  20. Internal tobacco industry research on olfactory and trigeminal nerve response to nicotine and other smoke components.

    PubMed

    Megerdichian, Christine L; Rees, Vaughan W; Wayne, Geoffrey Ferris; Connolly, Gregory N

    2007-11-01

    Evidence has shown that factors other than the central pharmacological effects of nicotine are important in promoting smoking behavior. One such non-nicotine effect includes sensory stimulation, which may promote smoking by developing learned associations with nicotine's rewarding effects, or by constituting a rewarding experience independent of nicotine. The present study used internal tobacco industry documents to examine industry efforts to understand and manipulate stimulation of the sensory nerves by tobacco smoke, and the influence of sensory stimulation on smoker behavior. Research focused on sensory nerves of the head and neck, including the olfactory nerve, which carries flavor and odor, and the trigeminal nerve, which carries irritant information. The tobacco industry maintained a systematic research program designed to elucidate an understanding of responses of sensory nerves to nicotine and other components of tobacco smoke, and attempted to develop nicotine-like compounds that would enhance sensory responses in smokers. Industry research appeared intended to aid in the development of new products with greater consumer appeal. The potential influence of sensory response in enhancing nicotine dependence through an associative mechanism was acknowledged by the tobacco industry, but evidence for research in this area was limited. These findings add to evidence of industry manipulation of sensory factors to enhance smoking behavior and may have implications for development of more effective treatment strategies, including more "acceptable" nicotine replacement therapies. PMID:17978985

  1. Peripheral nerve regeneration through collagen devices with different in vivo degradation characteristics

    E-print Network

    Harley, Brendan A. (Brendan Andrew), 1978-

    2002-01-01

    In the United States more than 200,000 people are treated each year for peripheral nerve injuries that require surgery. Functional recovery of motor and sensory capability is limited following autograft, the most common ...

  2. CHARACTERIZATION & TREATMENT OF LARGE SENSORY FIBER PERIPHERAL NEUROPATHY IN DIABETIC MICE

    E-print Network

    Muller, Karra

    2008-11-17

    Patients with large-fiber diabetic sensorimotor polyneuropathy (DPN) can develop altered sensorimotor function. Gait and balance control are regulated, in part, through large sensory nerves innervating muscle spindles. The overall goal...

  3. Violence Exposure in Real-Life, Video Games, Television, Movies, and the Internet: Is There Desensitization?

    ERIC Educational Resources Information Center

    Funk, Jeanne B.; Baldacci, Heidi Bechtoldt; Pasold; Tracie; Baumgardner, Jennifer

    2004-01-01

    It is believed that repeated exposure to real-life and to entertainment violence may alter cognitive, affective, and behavioral processes, possibly leading to desensitization. The goal of the present study was to determine if there are relationships between real-life and media violence exposure and desensitization as reflected in related…

  4. Flooding and Systematic Desensitization: Efficacy in Subclinical Phobics as a Function of Arousal

    ERIC Educational Resources Information Center

    Suarez, Yolanda; And Others

    1976-01-01

    Flooding and systematic desensitization procedures were investigated for possible interactions with subject arousal level on reduction in phobic reactions. No such interaction was found. Behaviorally and on GSR response, both flooding and systematic desensitization were effective, but only the latter was effective on subjective reports. (NG)

  5. Systematic Desensitization as a Method of Teaching a General Anxiety-Reducing Skill

    ERIC Educational Resources Information Center

    Zemore, Robert

    1975-01-01

    College students were treated with either a standard or modified version of systematic desensitization. Relative to a no-treatment control group, both treatment methods produced significant reductions in both the treated and untreated fears. The implications these findings have for two alternative conceptions of systematic desensitization are…

  6. Comparison of Anxiety Management Training and Desensitization in Reducing Test and Other Anxieties.

    ERIC Educational Resources Information Center

    Deffenbacher, Jerry L.; Shelton, John L.

    1978-01-01

    Effects of systematic desensitization and anxiety management training in reducing test anxiety and generalizing to other anxieties were compared. Both desensitization and anxiety management training produced significant reduction of text anxiety, but by follow-up, anxiety management training produced significantly more test-anxiety reduction on…

  7. Posterior interosseous nerve palsy in a machine gunner.

    PubMed

    Sonna, L A; Scott, B R

    1995-07-01

    We report the case of a 19-year-old Infantryman who developed posterior interosseous nerve palsy and a transient sensory deficit in a radial distribution after prolonged carrying of an M60 machine gun. Posterior interosseous nerve palsy has been reported in association with a variety of activities involving forceful, repetitive pronation and supination; however, to our knowledge, no previous cases of this palsy have been reported in association with use of a military weapon. PMID:7659246

  8. Short-term cholinergic desensitization of rat pancreatic secretory response

    SciTech Connect

    Asselin, J.; Larose, L.; Morisset, J.

    1987-03-01

    Dispersed pancreatic acini were first exposed to carbamylcholine (10/sup -7/-10/sup -4/ M) for 60 min, washed, and reexposed to this same agonist (10/sup -8/-10/sup -3/ M) for 15 min. During this second incubation, the functional secretory capacity of these acini was evaluated by measuring amylase release. Acini preexposed to concentrations of carbamylcholine of 10/sup -6/ M or greater showed shifts to the right in the subsequent carbamylcholine dose-response curves of amylase release. A 3-h recovery period (without carbamylcholine) did not restore the altered carbamylcholine dose-response curve. Ca/sup 2 +/ concentrations of 10/sup -7/ M or 2.5 x 10/sup -3/ M instead of 0.5 x 10/sup -3/ M during the 60-min preincubation did not affect the desensitization process. With use of N-(/sup 3/H)methylscopolamine to evaluate muscarinic receptors, the only changes observed after desensitization were a significant decrease in the high-affinity and an equivalent increase in that of the low-affinity receptors. After cholinergic exposure amylase release stimulated by caerulein was only slightly modified, whereas amylase release in response to a phorbol ester 12-O-tetradecanoylphorbol-13-acetate and to the ionophore A23187 was not altered. These data indicate that short-term desensitization with a cholinergic agent is relatively specific to muscarinic agonists, causes changes in the muscarinic receptor high-and low-affinity concentration but does not alter intracellular steps after calcium mobilization or protein kinase C activation known to be involved in the secretion process.

  9. Sensory receptors in monotremes.

    PubMed

    Proske, U; Gregory, J E; Iggo, A

    1998-07-29

    This is a summary of the current knowledge of sensory receptors in skin of the bill of the platypus, Ornithorhynchus anatinus, and the snout of the echidna, Tachyglossus aculeatus. Brief mention is also made of the third living member of the monotremes, the long-nosed echidna, Zaglossus bruijnii. The monotremes are the only group of mammals known to have evolved electroreception. The structures in the skin responsible for the electric sense have been identified as sensory mucous glands with an expanded epidermal portion that is innervated by large-diameter nerve fibres. Afferent recordings have shown that in both platypuses and echidnas the receptors excited by cathodal (negative) pulses and inhibited by anodal (positive) pulses. Estimates give a total of 40,000 mucous sensory glands in the upper and lower bill of the platypus, whereas there are only about 100 in the tip of the echidna snout. Recording of electroreceptor-evoked activity from the brain of the platypus have shown that the largest area dedicated to somatosensory input from the bill, S1, shows alternating rows of mechanosensory and bimodal neurons. The bimodal neurons respond to both electrosensory and mechanical inputs. In skin of the platypus bill and echidna snout, apart from the electroreceptors, there are structures called push rods, which consist of a column of compacted cells that is able to move relatively independently of adjacent regions of skin. At the base of the column are Merkel cell complexes, known to be type I slowly adapting mechanoreceptors, and lamellated corpuscles, probably vibration receptors. It has been speculated that the platypus uses its electric sense to detect the electromyographic activity from moving prey in the water and for obstacle avoidance. Mechanoreceptors signal contact with the prey. For the echidna, a role for the electrosensory system has not yet been established during normal foraging behaviour, although it has been shown that it is able to detect the presence of weak electric fields in water. Perhaps the electric sense is used to detect moving prey in moist soil. PMID:9720114

  10. Surgical anatomy of the retroperitoneal spaces, Part IV: retroperitoneal nerves.

    PubMed

    Mirilas, Petros; Skandalakis, John E

    2010-03-01

    We present surgicoanatomical topographic relations of nerves and plexuses in the retroperitoneal space: 1) six named parietal nerves, branches of the lumbar plexus: iliohypogastric, ilioinguinal, genitofemoral, lateral femoral cutaneous, obturator, femoral. 2) The sacral plexus is formed by the lumbosacral trunk, ventral rami of S1-S3, and part of S4; the remainder of S4 joining the coccygeal plexus. From this plexus originate the superior gluteal nerve, which passes backward through the greater sciatic foramen above the piriformis muscle; the inferior gluteal nerve also courses through the greater sciatic foramen, but below the piriformis; 3) sympathetic trunks: right and left lumbar sympathetic trunks, which comprise four interconnected ganglia, and the pelvic chains; 4) greater, lesser, and least thoracic splanchnic nerves (sympathetic), which pass the diaphragm and join celiac ganglia; 5) four lumbar splanchnic nerves (sympathetic), which arise from lumbar sympathetic ganglia; 6) pelvic splanchnic nerves (nervi erigentes), providing parasympathetic innervation to the descending colon and pelvic splanchna; and 7) autonomic (prevertebral) plexuses, formed by the vagus nerves, splanchnic nerves, and ganglia (celiac, superior mesenteric, aorticorenal). They include sympathetic, parasympathetic, and sensory (mainly pain) fibers. The autonomic plexuses comprise named parts: aortic, superior mesenteric, inferior mesenteric, superior hypogastric, and inferior hypogastric (hypogastric nerves). PMID:20349652

  11. Peripheral Nerve Ultrasound in Small Fiber Polyneuropathy.

    PubMed

    Ebadi, Hamid; Siddiqui, Hafsah; Ebadi, Sepehr; Ngo, MyLan; Breiner, Ari; Bril, Vera

    2015-11-01

    Routine nerve conduction studies are normal in patients with small fiber neuropathy (SFN), and a definitive diagnosis is based on skin biopsy revealing reduced intra-epidermal nerve fiber density (IENFD). In large fiber polyneuropathy, ultrasound (US) parameters indicate enlargement in cross-sectional area (CSA). This study was aimed at determining if similar changes in large fibers on US are apparent in patients with SFN. Twenty-five patients with SFN diagnosed by reduced IENFD and 25 age- and body mass index (BMI)-matched healthy controls underwent US studies of sural and superficial peroneal sensory nerves. The mean CSA of the sural nerve in SFN patients was 3.2 ± 0.8 mm(2), and in controls, 2.7 ± 0.6 mm(2) (p < 0.0070), and this was independent of sex. There was no difference in the thickness-to-width ratio or echogenicity of the nerves. US of the sural nerve in patients diagnosed with small fiber neuropathy reveals an enlarged cross-sectional area similar to that in large fiber polyneuropathy. PMID:26318562

  12. Clinical applications of drug desensitization in the Asia-Pacific region

    PubMed Central

    2011-01-01

    Drug desensitization is the induction, within hours to days, of a temporary state of tolerance to a drug which the patient has developed a hypersensitivity reaction to. It may be used for IgE and non-IgE mediated allergic reactions, and certain non-allergic reactions. The indication for desensitization is where no alternative medications are available for the treatment of that condition, and where the benefits of desensitization outweigh the risks. Desensitization is a therapeutic modality for drug allergy (similar to allergen specific immunotherapy for allergic rhinitis and insect venom anaphylaxis). In contrast, the drug provocation test is a diagnostic modality used to confirm or refute the diagnosis of drug allergy. This review discusses the clinical applications of desensitization for the treatment of common infectious, metabolic and cardiovascular diseases, and oncological conditions in the Asia-Pacific region. PMID:22053290

  13. NGF, BDNF, NT-3, and GDNF mRNA expression in rat skeletal muscle following denervation and sensory protection.

    PubMed

    Zhao, Chunnian; Veltri, Karen; Li, Songlin; Bain, James R; Fahnestock, Margaret

    2004-10-01

    Poor muscle and nerve functional recovery after nerve damage is a serious clinical problem, particularly if there is prolonged delay before nerve-muscle contact is reestablished. Our previous studies showed that sensory nerve cross-anastomosis (sensory protection) provides support to the denervated muscle. In the present study, we analyzed neurotrophic factor mRNA expression by RT-PCR in denervated rat gastrocnemius muscle receiving sensory protection with the saphenous nerve, compared to normal innervated muscle, to denervated muscle, and to denervated muscle repaired immediately with the peroneal (motor) nerve, after periods of 3 days to 3 months. No significant differences in mRNA levels of beta-actin, nerve growth factor, brain-derived neurotrophic factor or neurotrophin-3 were found between the sensory protection treatment and the denervated or the motor repair groups. However, sensory protection resulted in levels of muscle glial cell line-derived neurotrophic factor mRNA expression that were lower than in denervated muscle and higher than in muscle given immediate motor repair. These results demonstrate that glial cell line-derived neurotrophic factor mRNA is elevated following denervation but is partially down-regulated by sensory protection. Our study suggests that sensory protection provides a modified trophic environment by modulating neurotrophic factor synthesis in muscle. PMID:15672636

  14. Sensory testing of the human gastrointestinal tract

    PubMed Central

    Brock, Christina; Arendt-Nielsen, Lars; Wilder-Smith, Oliver; Drewes, Asbjřrn Mohr

    2009-01-01

    The objective of this appraisal is to shed light on the various approaches to screen sensory information in the human gut. Understanding and characterization of sensory symptoms in gastrointestinal disorders is poor. Experimental methods allowing the investigator to control stimulus intensity and modality, as well as using validated methods for assessing sensory response have contributed to the understanding of pain mechanisms. Mechanical stimulation based on impedance planimetry allows direct recordings of luminal cross-sectional areas, and combined with ultrasound and magnetic resonance imaging, the contribution of different gut layers can be estimated. Electrical stimulation depolarizes free nerve endings non-selectively. Consequently, the stimulation paradigm (single, train, tetanic) influences the involved sensory nerves. Visual controlled electrical stimulation combines the probes with an endoscopic approach, which allows the investigator to inspect and obtain small biopsies from the stimulation site. Thermal stimulation (cold or warm) activates selectively mucosal receptors, and chemical substances such as acid and capsaicin (either alone or in combination) are used to evoke pain and sensitization. The possibility of multimodal (e.g. mechanical, electrical, thermal and chemical) stimulation in different gut segments has developed visceral pain research. The major advantage is involvement of distinctive receptors, various sensory nerves and different pain pathways mimicking clinical pain that favors investigation of central pain mechanisms involved in allodynia, hyperalgesia and referred pain. As impairment of descending control mechanisms partly underlies the pathogenesis in chronic pain, a cold pressor test that indirectly stimulates such control mechanisms can be added. Hence, the methods undoubtedly represent a major step forward in the future characterization and treatment of patients with various diseases of the gut, which provides knowledge to clinicians about the underlying symptoms and treatment of these patients. PMID:19132764

  15. Acute median nerve palsy due to hemorrhaged schwannoma: case report

    PubMed Central

    2007-01-01

    Schwannomas are common, benign nerve tumors originating from the sheath of peripheral nerves. In this article, a 54 year old woman suffered from sudden onset motor and sensory deficit at her first radial three fingers on her right hand. Radiological investigations were normal. Electromyography diagnosed a median nerve entrapment neuropathy and urgent surgery was performed. Interestingly, a hemorrhaged mass was detected in the median nevre at the proximal end of the carpal ligament and was resected totally. Histopathological diagnosis was Schwannoma. The patient maintained a healthy status for five years. PMID:17892547

  16. IL-17 and VEGF are necessary for efficient corneal nerve regeneration

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The contribution of acute inflammation to sensory nerve regeneration was investigated in the murine cornea using a model of corneal abrasion that removes the stratified epithelium and subbasal nerve plexus. Abrasion induced accumulation of IL-17(+) CCR6(+) yo T cells, neutrophils, and platelets in t...

  17. Blockade by the local anaesthetic, tetracaine, of desensitization of Ca-induced Ca release after muscarinic stimulation in smooth muscle.

    PubMed Central

    Hishinuma, S.; Uchida, M. K.

    1991-01-01

    1. Desensitization of contractile responses dependent on release of intracellularly stored Ca elicited by carbachol, histamine or caffeine was measured after desensitizing treatment with carbachol or histamine in the presence or absence of local anaesthetics in Ca-free solution containing 2 mM EGTA in the smooth muscle of guinea-pig taenia caecum. 2. Histamine-induced homologous desensitization was inhibited by tetracaine and procainamide. Dibucaine did not exert an inhibitory effect on the desensitization. This is consistent with our previous findings concerning the effects of local anaesthetics on the desensitization of histamine H1-receptors measured under normal physiological conditions. 3. Carbachol induced a functional change of intracellular Ca stores which resulted in heterologous desensitization. Tetracaine completely blocked carbachol-induced desensitization of the caffeine-elicited contraction, but in the case of carbachol-induced desensitization of carbachol- and histamine-elicited contractions, this blocking effect of tetracaine was very weak and absent, respectively. The other local anaesthetics used did not affect the desensitization. These results suggest that the Ca-induced and inositol trisphosphate-induced Ca release mechanisms were both desensitized by carbachol and that the desensitization of the Ca-induced Ca release mechanism was selectively blocked by tetracaine. PMID:1884098

  18. End-to-side nerve suture in clinical practice.

    PubMed

    Mennen, Ulrich

    2003-07-01

    The phenomenon of lateral sprouting of axons into an end-to-side sutured recipient nerve is well documented. The exact nature, however, still needs further investigation. Since 1996, we have been continuously involved in primate research as well as using this end-to-side nerve suture (ETSNS) method in clinical practice. Fifty-six patients with a variety of conditions, ranging from brachial plexus avulsion to digital nerve lesions, have been operated. From our experience, it seems that the best results achieved are proximal motor re-innervation (e.g. biceps) and distal sensory re-innervation (e.g. volar skin of the hand). The discussion will cover various aspects for ETSNS in the human patient, such as indications, parameters, technique, and the importance of rehabilitation. ETSNS restores function in conditions previously difficult to operate, and may replace nerve grafting in many instances. It provides an additional method in our armamentarium in peripheral nerve surgery. PMID:12923932

  19. Clinical observations on sensory effects of trigeminal dorsal root section1

    PubMed Central

    Ley, Adolfo; Guitart, José Ma.

    1971-01-01

    Further clinical and operative support is presented for Dandy's discovery in 1929 of the presence of accessory sensory fibres of the fifth cranial nerve, running a separate course from the main sensory root at its exit from the pons. The advantages are stressed of Dandy's subcerebellar approach in selected cases for sparing those fibres as well as the motor root. Images PMID:5571312

  20. In vivo desensitization of glycogenolysis to Ca2+-mobilizing hormones in rat liver cells.

    PubMed Central

    Tsujimoto, G; Tsujimoto, A; Kato, K; Hashimoto, K

    1988-01-01

    Rat hepatocytes contain several types of Ca2+-linked receptors, all of which stimulate glycogen breakdown by increasing cytosolic free Ca2+ concentration [( Ca2+]c). In vivo desensitization of this Ca2+ messenger system was studied in hepatocytes isolated from either pheochromocytoma (PHEO)-harboring and chronically norepinephrine (NE)-infused rats. Homologous desensitization for alpha 1-adrenergic receptor-mediated phosphorylase activation developed in the early stage of PHEO rats (3-4 wk after implantation), whereas, in the later stage of tumor development or in the NE-infused rats, phosphorylase responses to all Ca2+-mobilizing stimulations were subsensitive (heterologous desensitization). In the homologous desensitization, the [Ca2+]c response to alpha 1-adrenergic stimulation was selectively reduced. We found, using the phenoxybenzamine inactivation method, that there was a linear relationship between alpha 1 receptor density and the [Ca2+]c response; consequently, the blunted [Ca2+]c response to alpha 1-adrenergic stimulation could not be explained by the 34% downregulation of alpha 1 receptors seen in these rats. These results indicated that uncoupling at a step proximal to alpha 1 receptor-stimulated [Ca2+]c increase is also of primary importance in homologous desensitization of phosphorylase activation. On the other hand, heterologous desensitization also involved alteration(s) at steps distal to the rise in [Ca2+]c. Our data demonstrate that prolonged exposure to catecholamines results in desensitization of the [Ca2+]c mobilization pathway and may involve multiple mechanisms. PMID:2848864

  1. Study of Sural Nerve Complex in Human Cadavers

    PubMed Central

    Seema, S. R.

    2013-01-01

    Aim. The sural nerve complex (SNC) consists of four named components: medial sural cutaneous nerve (MSCN), lateral sural cutaneous nerve (LSCN), peroneal communicating nerve (PCN), and sural nerve (SN). The formation and distribution of the sural nerve vary in different individuals. SN is universally recognized by surgeons as a site for harvesting an autologous nerve graft. The nerve is widely used for electrophysiological studies. Hence the study of sural nerve complex was taken up. Method. SNC was observed by dissecting 100 lower limbs in the department of anatomy at three different medical colleges, over a period of 10 years. Result. Typical SN was observed in 60% of the cases. MSCN was present in all the cases; in 15% of the cases the MSCN followed an intramural course. LSCN was present in 80% of the cases. PCN was present in 70% of the cases and in most of the cases calibre was larger than that of MSCN. Conclusion. The knowledge about the variation in the origin and course of the SN is important in evaluating sensory axonal loss in distal axonal neuropathies and should be borne in mind by clinicians and surgeons. PMID:25938105

  2. Overview of the Cranial Nerves

    MedlinePLUS

    ... Gaze Palsies Palsies of Cranial Nerves That Control Eye Movement Third Cranial Nerve (Oculomotor Nerve) Palsy Fourth Cranial ... You Know... Some cranial nerve disorders interfere with eye movement, causing double vision. Symptoms Symptoms depend on which ...

  3. Optic Nerve Imaging

    MedlinePLUS

    ... About Us Donate In This Section Optic Nerve Imaging email Send this article to a friend by ... may use one of these optic nerve computer imaging techniques as part of your glaucoma examination. By ...

  4. Electromechanical Nerve Stimulator

    NASA Technical Reports Server (NTRS)

    Tcheng, Ping; Supplee, Frank H., Jr.; Prass, Richard L.

    1993-01-01

    Nerve stimulator applies and/or measures precisely controlled force and/or displacement to nerve so response of nerve measured. Consists of three major components connected in tandem: miniature probe with spherical tip; transducer; and actuator. Probe applies force to nerve, transducer measures force and sends feedback signal to control circuitry, and actuator positions force transducer and probe. Separate box houses control circuits and panel. Operator uses panel to select operating mode and parameters. Stimulator used in research to characterize behavior of nerve under various conditions of temperature, anesthesia, ventilation, and prior damage to nerve. Also used clinically to assess damage to nerve from disease or accident and to monitor response of nerve during surgery.

  5. Ulnar nerve dysfunction

    MedlinePLUS

    ... the hand muscles (in severe cases) Weakness of hand flexing Tests may be needed, depending on your history, symptoms, ... MRI of the neck Nerve ultrasound Nerve conduction tests Recording of the electrical activity in muscles ( EMG ) X-rays

  6. Peripheral nerve regeneration and neurotrophic factors

    PubMed Central

    TERENGHI, GIORGIO

    1999-01-01

    The role of neurotrophic factors in the maintenance and survival of peripheral neuronal cells has been the subject of numerous studies. Administration of exogenous neurotrophic factors after nerve injury has been shown to mimic the effect of target organ-derived trophic factors on neuronal cells. After axotomy and during peripheral nerve regeneration, the neurotrophins NGF, NT-3 and BDNF show a well defined and selective beneficial effect on the survival and phenotypic expression of primary sensory neurons in dorsal root ganglia and of motoneurons in spinal cord. Other neurotrophic factors such as CNTF, GDNF and LIF also exert a variety of actions on neuronal cells, which appear to overlap and complement those of the neurotrophins. In addition, there is an indirect contribution of GGF to nerve regeneration. GGF is produced by neurons and stimulates proliferation of Schwann cells, underlining the close interaction between neuronal and glial cells during peripheral nerve regeneration. Different possibilities have been investigated for the delivery of growth factors to the injured neurons, in search of a suitable system for clinical applications. The studies reviewed in this article show the therapeutic potential of neurotrophic factors for the treatment of peripheral nerve injury and for neuropathies. PMID:10227662

  7. Engineering a multimodal nerve conduit for repair of injured peripheral nerve

    NASA Astrophysics Data System (ADS)

    Quigley, A. F.; Bulluss, K. J.; Kyratzis, I. L. B.; Gilmore, K.; Mysore, T.; Schirmer, K. S. U.; Kennedy, E. L.; O'Shea, M.; Truong, Y. B.; Edwards, S. L.; Peeters, G.; Herwig, P.; Razal, J. M.; Campbell, T. E.; Lowes, K. N.; Higgins, M. J.; Moulton, S. E.; Murphy, M. A.; Cook, M. J.; Clark, G. M.; Wallace, G. G.; Kapsa, R. M. I.

    2013-02-01

    Injury to nerve tissue in the peripheral nervous system (PNS) results in long-term impairment of limb function, dysaesthesia and pain, often with associated psychological effects. Whilst minor injuries can be left to regenerate without intervention and short gaps up to 2 cm can be sutured, larger or more severe injuries commonly require autogenous nerve grafts harvested from elsewhere in the body (usually sensory nerves). Functional recovery is often suboptimal and associated with loss of sensation from the tissue innervated by the harvested nerve. The challenges that persist with nerve repair have resulted in development of nerve guides or conduits from non-neural biological tissues and various polymers to improve the prognosis for the repair of damaged nerves in the PNS. This study describes the design and fabrication of a multimodal controlled pore size nerve regeneration conduit using polylactic acid (PLA) and (PLA):poly(lactic-co-glycolic) acid (PLGA) fibers within a neurotrophin-enriched alginate hydrogel. The nerve repair conduit design consists of two types of PLGA fibers selected specifically for promotion of axonal outgrowth and Schwann cell growth (75:25 for axons; 85:15 for Schwann cells). These aligned fibers are contained within the lumen of a knitted PLA sheath coated with electrospun PLA nanofibers to control pore size. The PLGA guidance fibers within the nerve repair conduit lumen are supported within an alginate hydrogel impregnated with neurotrophic factors (NT-3 or BDNF with LIF, SMDF and MGF-1) to provide neuroprotection, stimulation of axonal growth and Schwann cell migration. The conduit was used to promote repair of transected sciatic nerve in rats over a period of 4 weeks. Over this period, it was observed that over-grooming and self-mutilation (autotomy) of the limb implanted with the conduit was significantly reduced in rats implanted with the full-configuration conduit compared to rats implanted with conduits containing only an alginate hydrogel. This indicates return of some feeling to the limb via the fully-configured conduit. Immunohistochemical analysis of the implanted conduits removed from the rats after the four-week implantation period confirmed the presence of myelinated axons within the conduit and distal to the site of implantation, further supporting that the conduit promoted nerve repair over this period of time. This study describes the design considerations and fabrication of a novel multicomponent, multimodal bio-engineered synthetic conduit for peripheral nerve repair.

  8. Engineering a multimodal nerve conduit for repair of injured peripheral nerve.

    PubMed

    Quigley, A F; Bulluss, K J; Kyratzis, I L B; Gilmore, K; Mysore, T; Schirmer, K S U; Kennedy, E L; O'Shea, M; Truong, Y B; Edwards, S L; Peeters, G; Herwig, P; Razal, J M; Campbell, T E; Lowes, K N; Higgins, M J; Moulton, S E; Murphy, M A; Cook, M J; Clark, G M; Wallace, G G; Kapsa, R M I

    2013-02-01

    Injury to nerve tissue in the peripheral nervous system (PNS) results in long-term impairment of limb function, dysaesthesia and pain, often with associated psychological effects. Whilst minor injuries can be left to regenerate without intervention and short gaps up to 2 cm can be sutured, larger or more severe injuries commonly require autogenous nerve grafts harvested from elsewhere in the body (usually sensory nerves). Functional recovery is often suboptimal and associated with loss of sensation from the tissue innervated by the harvested nerve. The challenges that persist with nerve repair have resulted in development of nerve guides or conduits from non-neural biological tissues and various polymers to improve the prognosis for the repair of damaged nerves in the PNS. This study describes the design and fabrication of a multimodal controlled pore size nerve regeneration conduit using polylactic acid (PLA) and (PLA):poly(lactic-co-glycolic) acid (PLGA) fibers within a neurotrophin-enriched alginate hydrogel. The nerve repair conduit design consists of two types of PLGA fibers selected specifically for promotion of axonal outgrowth and Schwann cell growth (75:25 for axons; 85:15 for Schwann cells). These aligned fibers are contained within the lumen of a knitted PLA sheath coated with electrospun PLA nanofibers to control pore size. The PLGA guidance fibers within the nerve repair conduit lumen are supported within an alginate hydrogel impregnated with neurotrophic factors (NT-3 or BDNF with LIF, SMDF and MGF-1) to provide neuroprotection, stimulation of axonal growth and Schwann cell migration. The conduit was used to promote repair of transected sciatic nerve in rats over a period of 4 weeks. Over this period, it was observed that over-grooming and self-mutilation (autotomy) of the limb implanted with the conduit was significantly reduced in rats implanted with the full-configuration conduit compared to rats implanted with conduits containing only an alginate hydrogel. This indicates return of some feeling to the limb via the fully-configured conduit. Immunohistochemical analysis of the implanted conduits removed from the rats after the four-week implantation period confirmed the presence of myelinated axons within the conduit and distal to the site of implantation, further supporting that the conduit promoted nerve repair over this period of time. This study describes the design considerations and fabrication of a novel multicomponent, multimodal bio-engineered synthetic conduit for peripheral nerve repair. PMID:23283383

  9. Human periodontal ligament stem cells repair mental nerve injury

    PubMed Central

    Li, Bohan; Jung, Hun-Jong; Kim, Soung-Min; Kim, Myung-Jin; Jahng, Jeong Won; Lee, Jong-Ho

    2013-01-01

    Human periodontal ligament stem cells are easily accessible and can differentiate into Schwann cells. We hypothesized that human periodontal ligament stem cells can be used as an alternative source for the autologous Schwann cells in promoting the regeneration of injured peripheral nerve. To validate this hypothesis, human periodontal ligament stem cells (1 × 106) were injected into the crush-injured left mental nerve in rats. Simultaneously, autologous Schwann cells (1 × 106) and PBS were also injected as controls. Real-time reverse transcriptase polymerase chain reaction showed that at 5 days after injection, mRNA expression of low affinity nerve growth factor receptor was significantaly increased in the left trigeminal ganglion of rats with mental nerve injury. Sensory tests, histomorphometric evaluation and retrograde labeling demonstrated that at 2 and 4 weeks after injection, sensory function was significantly improved, the numbers of retrograde labeled sensory neurons and myelinated axons were significantly increased, and human periodontal ligament stem cells and autologous Schwann cells exhibited similar therapeutic effects. These findings suggest that transplantation of human periodontal ligament stem cells show a potential value in repair of mental nerve injury. PMID:25206604

  10. The Physics of Nerves

    E-print Network

    Heimburg, Thomas

    2010-01-01

    The accepted model for nerve pulse propagation in biological membranes seems insufficient. It is restricted to dissipative electrical phenomena and considers nerve pulses exclusively as a microscopic phenomenon. A simple thermodynamic model that is based on the macroscopic properties of membranes allows explaining more features of nerve pulse propagation including the phenomenon of anesthesia that has so far remained unexplained.

  11. Electrophysiological study of forearm sensory fiber crossover in Martin-Gruber anastomosis.

    PubMed

    Simonetti, S

    2001-03-01

    Although anatomical studies have shown that a crossover of sensory fibers is not rare in forearm Martin-Gruber median-ulnar anastomosis (MGA), it has been electrophysiologically described only in rare subjects. Using a near-nerve needle technique, the possibility of electrophysiologically detecting a forearm median-ulnar crossover of sensory fibers was investigated in 24 arms of 21 subjects with unilateral or bilateral MGA, by stimulating the fifth digit of the hand and recording along the median nerve. Small-amplitude elbow responses were found in the median nerve in 10 of the 24 arms but, in 9, the responses disappeared after lidocaine block of the ulnar nerve distal to the elbow sulcus, indicating their volume-conducted origin. In one subject with carpal tunnel syndrome and a subclinical ulnar neuropathy at the elbow, the elbow response was not affected by the ulnar block, thus confirming the presence of a sensory anastomosis in the forearm. In another subject with MGA, a clear-cut sensory response was recorded in the median nerve at the elbow by stimulating the fifth digit of the right hand but no anesthetic block was performed, because ulnar responses were absent above the elbow sulcus due to a severe lesion at the elbow. Thus, use of a near-nerve recording technique facilitates recognition of median-ulnar crossover of sensory fibers to the fifth digit, which is, however, uncommon. PMID:11353423

  12. Chronic electrical stimulation of transected peripheral nerves preserves anatomy and function in the primary somatosensory cortex.

    PubMed

    Herrera-Rincon, Celia; Torets, Carlos; Sanchez-Jimenez, Abel; Avendańo, Carlos; Panetsos, Fivos

    2012-12-01

    The structure and function of the central nervous system strongly depend on the organization and efficacy of the incoming sensory input. A disruption of somesthetic input severely alters the metabolic activity, electrophysiological properties and even gross anatomical features of the primary somatosensory cortex. Here we examined, in the rat somatosensory cortex, the neuroprotective and therapeutic effects of artificial sensory stimulation after irreversible unilateral transection of a peripheral sensory nerve (the infraorbital branch of the trigeminal nerve). The proximal stump of the nerve was inserted into a silicon tube with stimulating electrodes, through which continuous electrical stimulation was applied for 12 h/day (square pulses of 100 ?s, 3.0 V, at 20 Hz) for 4 weeks. Deafferented animals showed significant decreases in cortical evoked potentials, cytochrome oxidase staining intensity (layers II-IV), cortical volume (layer IV) and number of parvalbumin-expressing (layers II-IV) and calbindin-D28k-expressing (layers II/III) interneurons. These deafferentation-dependent effects were largely absent in the nerve-stimulated animals. Together, these results provide evidence that chronic electrical stimulation has a neuroprotective and preservative effect on the sensory cortex, and raise the possibility that, by controlling the physical parameters of an artificial sensory input to a sectioned peripheral nerve, chronically deafferented brain regions could be maintained at near-'normal' conditions. Our findings could be important for the design of sensory neuroprostheses and for therapeutic purposes in brain lesions or neural degenerative processes. PMID:23006217

  13. Evaluation of Nerve Conduction Studies in Obese Children With Insulin Resistance or Impaired Glucose Tolerance.

    PubMed

    Ince, Hülya; Ta?demir, Haydar Ali; Aydin, Murat; Ozyürek, Hamit; Tilki, Hacer Erdem

    2015-07-01

    The aim of the study was to investigate nerve conduction studies in terms of neuropathic characteristics in obese patients who were in prediabetes stage and also to determine the abnormal findings. The study included 69 obese adolescent patients between April 2009 and December 2010. All patients and control group underwent motor (median, ulnar, tibial, and peroneal) and sensory (median, ulnar, sural, and medial plantar) nerve conduction studies and sympathetic skin response test. Sensory response amplitude of the medial plantar nerve was significantly lower in the patients with impaired glucose tolerance and insulin resistance. To our knowledge, the present study is the first study demonstrating the development of sensory and autonomic neuropathy due to metabolic complications of obesity in adolescent children even in the period without development of diabetes mellitus. We recommend that routine electrophysiological examinations be performed, using medial plantar nerve conduction studies and sympathetic skin response test. PMID:25342307

  14. Sensory Guillain-Barré syndrome: A case report

    PubMed Central

    ZHANG, JING; LIU, NA; ZHANG, ZHE-CHENG; ZHENG, RUI-ZHI; LI, QIAN

    2014-01-01

    A 58-year-old female exhibited the onset of symmetrical sensory abnormalities of the face and extremities. The neurological examination revealed normal muscle strength with abated or absent tendon reflexes. The patient experienced symmetrical glove- and stocking-type pinprick sensations in the distal extremities and a loss of temperature sensation, but had normal proprioception and vibration senses and joint topesthesia. The lumbar puncture showed protein cell separation at the fifth week after the onset of symptoms. At the same time-point, the electrophysiological examination showed demyelination changes involving the trigeminal nerve and the somatic motor nerve. Needle electromyography revealed normal results. The clinical symptoms ceased progression at the fourth week after symptom onset, and began to improve from the sixth. This case was considered to be sensory Guillain-Barré syndrome, which was characterized by its cranial nerve involvement. PMID:25371720

  15. Lentiviral-mediated transfer of CDNF promotes nerve regeneration and functional recovery after sciatic nerve injury in adult rats

    SciTech Connect

    Cheng, Lei; Liu, Yi; Zhao, Hua; Zhang, Wen; Guo, Ying-Jun; Nie, Lin

    2013-10-18

    Highlights: •CDNF was successfully transfected by a lentiviral vector into the distal sciatic nerve. •CDNF improved S-100, NF200 expression and nerve regeneration after sciatic injury. •CDNF improved the remyelination and thickness of the regenerated sciatic nerve. •CDNF improved gastrocnemius muscle weight and sciatic functional recovery. -- Abstract: Peripheral nerve injury is often followed by incomplete and unsatisfactory functional recovery and may be associated with sensory and motor impairment of the affected limb. Therefore, a novel method is needed to improve the speed of recovery and the final functional outcome after peripheral nerve injuries. This report investigates the effect of lentiviral-mediated transfer of conserved dopamine neurotrophic factor (CDNF) on regeneration of the rat peripheral nerve in a transection model in vivo. We observed notable overexpression of CDNF protein in the distal sciatic nerve after recombinant CDNF lentiviral vector application. We evaluated sciatic nerve regeneration after surgery using light and electron microscopy and the functional recovery using the sciatic functional index and target muscle weight. HE staining revealed better ordered structured in the CDNF-treated group at 8 weeks post-surgery. Quantitative analysis of immunohistochemistry of NF200 and S-100 in the CDNF group revealed significant improvement of axonal and Schwann cell regeneration compared with the control groups at 4 weeks and 8 weeks after injury. The thickness of the myelination around the axons in the CDNF group was significantly higher than in the control groups at 8 weeks post-surgery. The CDNF group displayed higher muscle weights and significantly increased sciatic nerve index values. Our findings suggest that CDNF gene therapy could provide durable and stable CDNF protein concentration and has the potential to enhance peripheral nerve regeneration, morphological and functional recovery following nerve injury, which suggests a promising strategy for peripheral nerve repair.

  16. Quantifying Hierarchy Stimuli in Systematic Desensitization Via GSR: A Preliminary Investigation

    ERIC Educational Resources Information Center

    Barabasz, Arreed F.

    1974-01-01

    The aim of the method for quantifying hierarchy stimuli by Galvanic Skin Resistance recordings is to improve the results of systematic desensitization by attenuating the subjective influences in hierarchy construction which are common in traditional procedures. (Author/CS)

  17. SPINAL CORD Nerves Dermatomes

    E-print Network

    Oliver, Douglas L.

    Columns #12;Where are the sensory and motor nuclei?nuclei? Alar plate ­ sensory ·Basal plate ­ motor #12 Reflex PAIN RECEPTORS EXTENSOR EXTENSOR FLEXOR FLEXOR #12;Renshaw Cell Ia from spindlep Renshaw Cell

  18. Pitocin and autism: An analysis of oxytocin receptor desensitization in the fetus.

    PubMed

    Gottlieb, Mark M

    2016-02-01

    The risk of Pitocin as a cause of autism attributable to oxytocin receptor desensitization in the brain of the fetus is evaluated in terms of a mathematical model. A composite unit, D, for oxytocin receptor desensitization levels is established with the form ((IU-h)/ml)E-3, where IU is the international unit for oxytocin. The desensitization values for oxytocin receptor desensitization at a concentration of 10nmol of oxytocin per liter for 3, 4.2 and 6h corresponding to 0%, 50% and 100% desensitization are calculated to be 15 D, 21 D, and 30 D, respectively. The permeability of the blood-brain barrier in the fetus to oxytocin is discussed, and the upper limit of the concentration of Pitocin in the placenta, and its possible diffusion into the blood and brain of the fetus, is calculated for a routine dose of 6milliU per minute of Pitocin over a 12h labor. This dose of Pitocin is shown to result in a desensitization value in units of D that is more than a factor of 10 below the 0% desensitization value of 15 D. This indicates that routine doses of Pitocin are not a significant cause of autism attributable to oxytocin receptor desensitization. This is consistent with the findings of a major epidemiological study of the association of Pitocin with autism in Denmark entitled, "Oxytocin-augmented labor and risk for males", Behavioral Brain Research, May 1, 2015; 284:207-212, which found no association between the use of Pitocin during labor and the incidence of autism for females, and a modest association for males. PMID:26545832

  19. Endogenous arginine-phenylalanine-amide-related peptides alter steady-state desensitization of ASIC1a.

    PubMed

    Sherwood, Thomas W; Askwith, Candice C

    2008-01-25

    The acid-sensing ion channels (ASICs) are proton-gated, voltage-insensitive cation channels expressed throughout the nervous system. ASIC1a plays a role in learning, pain, and fear-related behaviors. In addition, activation of ASIC1a during prolonged acidosis following cerebral ischemia induces neuronal death. ASICs undergo steady-state desensitization, a characteristic that limits ASIC1a activity and may play a prominent role in the prevention of ASIC1a-evoked neuronal death. In this study, we found exogenous and endogenous arginine-phenylalanine-amide (RF-amide)-related peptides decreased the pH sensitivity of ASIC1a steady-state desensitization. During conditions that normally induced steady-state desensitization, these peptides profoundly enhanced ASIC1a activity. We also determined that human ASIC1a required more acidic pH to undergo steady-state desensitization compared with mouse ASIC1a. Surprisingly, steady-state desensitization of human ASIC1a was also affected by a greater number of peptides compared with mouse ASIC1a. Mutation of five amino acids in a region of the extracellular domain changed the characteristics of human ASIC1a to those of mouse ASIC1a, suggesting that this region plays a pivotal role in neuropeptide and pH sensitivity of steady-state desensitization. Overall, these experiments lend vital insight into steady-state desensitization of ASIC1a and expand our understanding of the structural determinants of RF-amide-related peptide modulation. Furthermore, our finding that endogenous peptides shift steady-state desensitization suggests that RF-amides could impact the role of ASIC1a in both pain and neuronal damage following stroke and ischemia. PMID:17984098

  20. Corneal confocal microscopy reveals trigeminal small sensory fiber neuropathy in amyotrophic lateral sclerosis

    PubMed Central

    Ferrari, Giulio; Grisan, Enrico; Scarpa, Fabio; Fazio, Raffaella; Comola, Mauro; Quattrini, Angelo; Comi, Giancarlo; Rama, Paolo; Riva, Nilo

    2014-01-01

    Although subclinical involvement of sensory neurons in amyotrophic lateral sclerosis (ALS) has been previously demonstrated, corneal small fiber sensory neuropathy has not been reported to-date. We examined a group of sporadic ALS patients with corneal confocal microscopy, a recently developed imaging technique allowing in vivo observation of corneal small sensory fibers. Corneal confocal microscopy (CCM) examination revealed a reduction of corneal small fiber sensory nerve number and branching in ALS patients. Quantitative analysis demonstrated an increase in tortuosity and reduction in length and fractal dimension of ALS patients’ corneal nerve fibers compared to age-matched controls. Moreover, bulbar function disability scores were significantly related to measures of corneal nerve fibers anatomical damage. Our study demonstrates for the first time a corneal small fiber sensory neuropathy in ALS patients. This finding further suggests a link between sporadic ALS and facial-onset sensory and motor neuronopathy (FOSMN) syndrome, a rare condition characterized by early sensory symptoms (with trigeminal nerve distribution), followed by wasting and weakness of bulbar and upper limb muscles. In addition, the finding supports a model of neurodegeneration in ALS as a focally advancing process. PMID:25360111

  1. Effects of lead acetate on guinea pig - cochear microphonics, action potential, and motor nerve conduction velocity

    SciTech Connect

    Yamamura, K.; Maehara, N.; Terayama, K.; Ueno, N.; Kohyama, A.; Sawada, Y.; Kishi, R.

    1987-04-01

    Segmental demyelination and axonal degeneration of motor nerves induced by lead exposure is well known in man, and animals. The effect of lead acetate exposure to man may involve the cranial nerves, since vertigo and sensory neuronal deafness have been reported among lead workers. However, there are few reports concerning the dose-effects of lead acetate both to the peripheral nerve and the cranial VII nerve with measurement of blood lead concentration. The authors investigated the effects of lead acetate to the cochlea and the VIII nerve using CM (cochlear microphonics) and AP (action potential) of the guinea pigs. The effects of lead acetate to the sciatic nerve were measured by MCV of the sciatic nerve with measurement of blood lead concentration.

  2. Neural stem/progenitor cell properties of glial cells in the adult mouse auditory nerve

    PubMed Central

    Lang, Hainan; Xing, Yazhi; Brown, LaShardai N.; Samuvel, Devadoss J.; Panganiban, Clarisse H.; Havens, Luke T.; Balasubramanian, Sundaravadivel; Wegner, Michael; Krug, Edward L.; Barth, Jeremy L.

    2015-01-01

    The auditory nerve is the primary conveyor of hearing information from sensory hair cells to the brain. It has been believed that loss of the auditory nerve is irreversible in the adult mammalian ear, resulting in sensorineural hearing loss. We examined the regenerative potential of the auditory nerve in a mouse model of auditory neuropathy. Following neuronal degeneration, quiescent glial cells converted to an activated state showing a decrease in nuclear chromatin condensation, altered histone deacetylase expression and up-regulation of numerous genes associated with neurogenesis or development. Neurosphere formation assays showed that adult auditory nerves contain neural stem/progenitor cells (NSPs) that were within a Sox2-positive glial population. Production of neurospheres from auditory nerve cells was stimulated by acute neuronal injury and hypoxic conditioning. These results demonstrate that a subset of glial cells in the adult auditory nerve exhibit several characteristics of NSPs and are therefore potential targets for promoting auditory nerve regeneration. PMID:26307538

  3. Temporal mismatch between pain behaviour, skin Nerve Growth Factor and intra-epidermal nerve fibre density in trigeminal neuropathic pain

    PubMed Central

    2014-01-01

    Background The neurotrophin Nerve Growth factor (NGF) is known to influence the phenotype of mature nociceptors, for example by altering synthesis of neuropeptides, and changes in NGF levels have been implicated in the pathophysiology of chronic pain conditions such as neuropathic pain. We have tested the hypothesis that after partial nerve injury, NGF accumulates within the skin and causes ‘pro-nociceptive’ phenotypic changes in the remaining population of sensory nerve fibres, which could underpin the development of neuropathic pain. Results Eleven days after chronic constriction injury of the rat mental nerve the intra-epidermal nerve fibre density of the chin skin from had reduced from 11.6?±?4.9 fibres/mm to 1.0?±?0.4 fibres/mm; this slowly recovered to 2.4?±?2.0 fibres/mm on day 14 and 4.0?±?0.8 fibres/mm on day 21. Cold hyperalgesia in the ipsilateral lower lip was detectable 11 days after chronic constriction injury, although at this time skin [NGF] did not differ between sides. At 14 days post-injury, there was a significantly greater [NGF] ipsilaterally compared to contralaterally (ipsilateral?=?111?±?23 pg/mg, contralateral?=?69?±?13 pg/mg), but there was no behavioural evidence of neuropathic pain at this time-point. By 21 days post-injury, skin [NGF] was elevated bilaterally and there was a significant increase in the proportion of TrkA-positive (the high-affinity NGF receptor) intra-epidermal nerve fibres that were immunolabelled for the neuropeptide Calcitonin Gene-related peptide. Conclusions The temporal mismatch in behaviour, skin [NGF] and phenotypic changes in sensory nerve fibres indicate that increased [NGF] does not cause hyperalgesia after partial mental nerve injury, although it may contribute to the altered neurochemistry of cutaneous nerve fibres. PMID:24380503

  4. Effect of combined nicotine and shrapnel exposure on pain measures and gait after nerve injury.

    PubMed

    Rittenhouse, Bradley; Hill-Pryor, Crystal D; McConathy, Adam; Parker, Peter; Franco, Nelson; Toussaint, Esra; Barker, Darrell; Prasad, Balakrishna; Pizarro, Jose M

    2011-11-01

    A significant fraction of military soldiers sustain nerve injury and use tobacco or nicotine containing products. Healing of nerve injuries is influenced by many factors, such as degree of original injury, healing potential of the nerve, and general health of patient. However, recently, it has been demonstrated that the presence of retained insoluble metal fragments decreases healing. The effects of systemic nicotine administration, with or without metal fragments at the site of nerve injury, were evaluated. Both the nicotine-administered groups (nicotine, nicotine + shrapnel) showed significant increase in the peroneal function compared with untreated controls, as assessed by paw area (p < 0.05). Furthermore, to test possible role of altered sensory function, we used the hot plate assay. Latency to withdraw paw from a hot plate was significantly shorter in nicotine groups (p < 0.05). These data indicate that nicotine improves sensory and motor aspects of nerve function, in the presence or absence of shrapnel. PMID:22165666

  5. Effects of polysialic acid on sensory innervation of the cornea.

    PubMed

    Mao, Xiuli; Zhang, Yuntao; Schwend, Tyler; Conrad, Gary W

    2015-02-15

    Sensory trigeminal growth cones innervate the cornea in a coordinated fashion during embryonic development. Polysialic acid (polySia) is known for its important roles during nerve development and regeneration. The purpose of this work is to determine whether polySia, present in developing eyefronts and on the surface of sensory nerves, may provide guidance cues to nerves during corneal innervation. Expression and localization of polySia in embryonic day (E)5-14 chick eyefronts and E9 trigeminal ganglia were identified using Western blotting and immunostaining. Effects of polySia removal on trigeminal nerve growth behavior were determined in vivo, using exogenous endoneuraminidase (endoN) treatments to remove polySia substrates during chick cornea development, and in vitro, using neuronal explant cultures. PolySia substrates, made by the physical adsorption of colominic acid to a surface coated with poly-d-lysine (PDL), were used as a model to investigate functions of the polySia expressed in axonal environments. PolySia was localized within developing eyefronts and on trigeminal sensory nerves. Distributions of PolySia in corneas and pericorneal regions are developmentally regulated. PolySia removal caused defasciculation of the limbal nerve trunk in vivo from E7 to E10. Removal of polySia on trigeminal neurites inhibited neurite outgrowth and caused axon defasciculation, but did not affect Neural Cell Adhesion Molecule (NCAM) expression or Schwann cell migration in vitro. PolySia substrates in vitro inhibited outgrowth of trigeminal neurites and promoted their fasciculation. In conclusion, polySia is localized on corneal nerves and in their targeting environment during early developing stages of chick embryos. PolySias promote fasciculation of trigeminal axons in vivo and in vitro, whereas, in contrast, their removal promotes defasciculation. PMID:25478909

  6. End-to-side nerve repair in the upper extremity of rat.

    PubMed

    Bontioti, Eleana; Kanje, Martin; Lundborg, Göran; Dahlin, Lars B

    2005-03-01

    The end-to-side nerve-repair technique, i.e., when the distal end of an injured nerve is attached end-to-side to an intact nerve trunk in an attempt to attract nerve fibers by collateral sprouting, has been used clinically. The technique has, however, been questioned. The aim of the present study was to investigate end-to-side repair in the upper extremity of rats with emphasis on functional recovery, source, type, and extent of regenerating fibers. End-to-side repair was used in the upper limb, and the radial or both median/ulnar nerves were attached end-to-side to the musculocutaneous nerve. Pawprints and tetanic muscle force were used to evaluate functional recovery during a 6-month recovery period, and double retrograde labeling was used to detect the source of the regenerated nerve fibers. The pawprints showed that, in end-to-side repair of either one or two recipient nerves, there was a recovery of toe spreading to 60-72% of the preoperative value (lowest value around 47%). Electrical stimulation of the end-to-side attached radial or median/ulnar nerves 6 months after repair resulted in contraction of muscles in the forearm innervated by these nerves (median tetanic muscle force up to 70% of the contralateral side). Retrograde labeling showed that both myelinated (morphometry) sensory and motor axons were recruited to the end-to-side attached nerve and that these axons emerged from the motor and sensory neuronal pool of the brachial plexus. Double retrograde labeling indicated that collateral sprouting was one mechanism by which regeneration occurred. We also found that two recipient nerves could be supported from a single donor nerve. Our results suggest that end-to-side repair may be one alternative to reconstruct a brachial plexus injury when no proximal nerve end is available. PMID:15703019

  7. Biological and Electrophysiologic Effects of Poly(3,4-ethylenedioxythiophene) on Regenerating Peripheral Nerve Fibers

    PubMed Central

    Baghmanli, Ziya; Sugg, Kristoffer B.; Wei, Benjamin; Shim, Bong S.; Martin, David C.; Cederna, Paul S.; Urbanchek, Melanie G.

    2014-01-01

    Background Uninjured peripheral nerves in upper-limb amputees represent attractive sites for connectivity with neuroprostheses because their predictable internal topography allows for precise sorting of motor and sensory signals. The inclusion of poly(3,4-ethylenedioxythiophene) reduces impedance and improves charge transfer at the biotic-abiotic interface. This study evaluates the in vivo performance of poly(3,4-ethylenedioxythiophene)–coated interpositional decellularized nerve grafts across a critical nerve conduction gap, and examines the long-term effects of two different poly(3,4-ethylenedioxythiophene) formulations on regenerating peripheral nerve fibers. Methods In 48 rats, a 15-mm gap in the common peroneal nerve was repaired using a nerve graft of equivalent length, including (1) decellularized nerve chemically polymerized with poly(3,4-ethylenedioxythiophene) (dry); (2) decellularized nerve electrochemically polymerized with poly(3,4-ethylenedioxythiophene) (wet); (3) intact nerve; (4) autogenous nerve graft; (5) decellularized nerve alone; and (6) unrepaired nerve gap controls. All groups underwent electrophysiologic characterization at 3 months, and nerves were harvested for histomorphometric analysis. Results Conduction velocity was significantly faster in the dry poly(3,4-ethylenedioxythiophene) group compared with the sham, decellularized nerve, and wet poly(3,4-ethylenedioxythiophene) groups. Maximum specific force for the dry poly(3,4-ethylenedioxythiophene) group was more similar to sham than were decellularized nerve controls. Evident neural regeneration was demonstrated in both dry and wet poly(3,4-ethylenedioxythiophene) groups by the presence of normal regenerating axons on histologic cross-section. Conclusions Both poly(3,4-ethylenedioxythiophene) formulations were compatible with peripheral nerve regeneration at 3 months. This study supports poly(3,4-ethylenedioxythiophene) as a promising adjunct for peripheral nerve interfaces for prosthetic control and other biomedical applications because of its recognized ionic-to-electronic coupling potential. PMID:23897336

  8. Chinese Medicine in Diabetic Peripheral Neuropathy: Experimental Research on Nerve Repair and Regeneration

    PubMed Central

    Piao, Yuanlin; Liang, Xiaochun

    2012-01-01

    Diabetic peripheral neuropathy (DPN) is one of the most common complications of chronic diabetes mellitus. Pathological characteristics of DPN include axonal atrophy, nerve demyelination, and delayed regeneration of peripheral sensory nerve fibers. The goal of treatment in DPN is not only to ameliorate neurological symptoms but also to slow or reverse the underlying neurodegenerative process. Schwann cells and neurotrophic factors play important roles in the repair and regeneration of peripheral nerves. The present paper reviews current studies and evidence regarding the neurological effects of traditional Chinese medicine, with an emphasis on recent developments in the area of nerve repair and regeneration in DPN. PMID:22927874

  9. Unusually large quiescent ancient schwannoma of hypoglossal nerve.

    PubMed

    Wanjari, Sangeeta P; Wanjari, Panjab V; Parwani, Rajkumar N; Tekade, Satyajitraje A

    2013-01-01

    Ancient schwannoma is considered as a variant of schwannoma, comprising about 10% of all schwanommas. Schwannoma is a benign neoplasm derived from the nerve sheath of peripheral motor, sensory and sympathetic nerves and from the cranial nerve pairs. It usually presents as a solitary soft-tissue lesion which is slow growing, encapsulated and is often associated with nerve attached peripherally. Diagnosis is often confirmed with the microscopic examination. The long standing schwannoma attributes to degenerative changes and is termed "ancient" schwannoma. Present case is of a 68-year-old female patient who reported with an asymptomatic large swelling below mandible on the left side since last 23 years. The lesion was surgically excised under general anesthesia. PMID:24552945

  10. Neurotoxicity of perineural vs intraneural-extrafascicular injection of liposomal bupivacaine in the porcine model of sciatic nerve block.

    PubMed

    Damjanovska, M; Cvetko, E; Hadzic, A; Seliskar, A; Plavec, T; Mis, K; Vuckovic Hasanbegovic, I; Stopar Pintaric, T

    2015-12-01

    Liposomal bupivacaine is a prolonged-release local anaesthetic, the neurotoxicity of which has not yet been determined. We used quantitative histomorphometric and immunohistochemical analyses to evaluate the neurotoxic effect of liposomal bupivacaine after perineural and intraneural (extrafascicular) injection of the sciatic nerve in pigs. In this double-blind prospective randomised trial, 4 ml liposomal bupivacaine 1.3% was injected either perineurally (n = 5) or intraneurally extrafascicularly (n = 5). Intraneural-extrafascicular injection of saline (n = 5) was used as a control. After emergence from anaesthesia, neurological examinations were conducted over two weeks. After harvesting the sciatic nerves, no changes in nerve fibre density or myelin width indicative of nerve injury were observed in any of the groups. Intraneural injections resulted in longer sensory blockade than perineural (p < 0.003) without persistent motor or sensory deficit. Sciatic nerve block with liposomal bupivacaine in pigs did not result in histological evidence of nerve injury. PMID:26338496

  11. Evodiamine suppresses capsaicin-induced thermal hyperalgesia through activation and subsequent desensitization of the transient receptor potential V1 channels.

    PubMed

    Iwaoka, Emiko; Wang, Shenglan; Matsuyoshi, Nobuyuki; Kogure, Yoko; Aoki, Shunji; Yamamoto, Satoshi; Noguchi, Koichi; Dai, Yi

    2016-01-01

    Evodiae fructus (EF), a fruit of Evodia rutaecarpa Bentham, has long been used as an analgesic drug in traditional Chinese and Japanese medicine. However, the underlying molecular mechanism of its pharmacological action is unclear. Here, using calcium imaging, whole-cell patch-clamp recording, and behavioral analysis, we investigated the pharmacological action of EF and its principal compound, evodiamine, on the transient receptor potential (TRP) V1 channels. Dorsal root ganglion (DRG) neurons and TRPV1- or TRPA1-transfected human embryonic kidney-derived (HEK) 293 cells were used for calcium imaging or whole-cell patch-clamp recording. Twenty male adult Sprague-Dawley rats were used for the capsaicin-induced thermal hyperalgesia behavioral analyses. We found that evodiamine induced significant increases in intracellular calcium and robust inward currents in a subpopulation of isolated rat DRG neurons, most of which were also sensitive to capsaicin. The effect of evodiamine was completely blocked by capsazepine, a competitive antagonist of TRPV1. Evodiamine induced significant inward currents in TRPV1-, but not TRPA1-transfected HEK293 cells. Pretreatment with evodiamine reduced capsaicin-induced currents significantly. Furthermore, the in vivo pre-treatment of evodiamine suppressed thermal hyperalgesia induced by intraplantar injection of capsaicin in rats. These results identify that the analgesic effect of EF and evodiamine may be due to the activation and subsequent desensitization of TRPV1 in sensory neurons. PMID:26188960

  12. Activin is a nerve cell survival molecule.

    PubMed

    Schubert, D; Kimura, H; LaCorbiere, M; Vaughan, J; Karr, D; Fischer, W H

    1990-04-26

    The structures of five neurotrophic molecules have so far been published. Nerve growth factor, fibroblast growth factor and purpurin, have been identified as nerve-cell survival molecules. More recently, brain-derived neurotrophic factor (BDNF) and ciliary neurotrophic factor have been cloned and sequenced. As all these proteins stimulate the survival of ciliary or sensory neurons, a new cell survival assay is required if novel neurotrophic molecules are to be discovered. P19 teratoma cells differentiate to nerve-like cells in the presence of 5 x 10(-7) M retinoic acid (RA). But when P19 cells are plated in N2 synthetic medium without being exposed to RA, they die within 48 h. In an attempt to identify a molecule(s) that can substitute for RA in promoting P19 survival, we assayed serum-free growth-conditioned media for their ability to promote P19 survival. One cell line from the rat eye secreted a molecule that promoted the survival of P19 cells and some types of nerve cell. We identified this molecule as activin, better known for its role in hormone secretion. PMID:2330043

  13. Overview of the Cranial Nerves

    MedlinePLUS

    ... nerves—the cranial nerves—lead directly from the brain to various parts of the head, neck, and trunk. Some of the cranial nerves are ... cranial nerves emerge from the underside of the brain, pass through ... to parts of the head, neck, and trunk. The nerves are named and numbered, ...

  14. Peripheral communications of intercostobrachial nerve Peripheral communications of the intercostobrachial nerve in relation to the alar thoracic artery

    PubMed Central

    Rustagi, Shaifaly Madan; Sharma, Mona; Singh, Nidhi; Mehta, Vandana; Suri, Rajesh K; Rath, Gayatri

    2015-01-01

    The intercostobrachial nerve (ICBN) is often encountered during axillary dissection for axillary lymph node dissection (ALND) for diagnostic and therapeutic surgery for mastectomy. The present report is a case observed in the Department of Anatomy at Vardhman Mahavir Medical College, Delhi during routine dissection of the upper extremity of a male cadaver for first year undergraduate medical students. On the right side, the medial cord of brachial plexus gave two medial cutaneous nerves of arm. Both the nerves were seen communicating with the branches of the ICBN. The ICBN and one of its branches were surrounding the termination of an alar thoracic artery. These peripheral neural connections of the ICBN with the branches of the medial cord can be a cause of sensory impairment during axillary procedures done for mastectomy or exploration of long thoracic nerves. The alar thoracic artery found in relation to the ICBN could further be a cause of vascular complications during such procedures. PMID:25802820

  15. A desensitization-selective potentiator of AMPA-type glutamate receptors.

    PubMed

    Sekiguchi, Masayuki; Nishikawa, Kaori; Aoki, Shunsuke; Wada, Keiji

    2002-08-01

    1: We examined the effects of PEPA, an allosteric potentiator of AMPA receptors, on AMPA receptor kinetics. 2: PEPA did not affect the deactivation of glutamate responses but potently attenuated the extent of receptor desensitization without slowing the onset of desensitization in most of the recombinant AMPA receptors (GluR1-flip, GluR1-flop, GluR3-flip, GluR3-flip+GluR2-flip, and GluR3-flop+GluR2-flop) expressed in Xenopus oocytes. For the GluR3-flop subunit, PEPA attenuated the extent of desensitization and only weakly prolonged deactivation (1.3 fold). 3: PEPA did not significantly affect recovery from desensitization in oocytes expressing GluR3-flip, GluR1-flop, and GluR1-flop, but weakly accelerated (2.6 fold) recovery from desensitization in oocytes expressing GluR3-flop. 4: PEPA's effect on desensitization of GluR3-flop-containing receptors is unique in that onset is very slow. 5: Simulation studies using simplified kinetic models for AMPA receptors are utilized to explore the differential effects of PEPA on GluR3-flip and -flop. It is possible to simulate the action on GluR3-flip by modulating two rate constants in a 12-state kinetic model. For simulation of the action on GluR3-flop, the 12-state kinetic model is not enough, and it is necessary to invoke a 13th state, a PEPA-bound receptor to which glutamate cannot bind. 6: These results suggest that attenuation of extent of desensitization represents the principal mechanism underlying the potentiation of AMPA receptors by PEPA, and that PEPA exhibits different mechanisms with respect to GluR3-flip and GluR3-flop. PMID:12145103

  16. Diacetyl Increases Sensory Innervation and Substance P Production in Rat Trachea

    PubMed Central

    Goravanahally, Madhusudan P.; Hubbs, Ann F.; Fedan, Jeffery S.; Kashon, Michael L.; Battelli, Lori A.; Mercer, Robert R.; Goldsmith, W. Travis; Jackson, Mark C.; Cumpston, Amy; Frazer, David G.; Dey, Richard D.

    2015-01-01

    Inhalation of diacetyl, a butter flavoring, causes airway responses potentially mediated by sensory nerves. This study examines diacetyl-induced changes in sensory nerves of tracheal epithelium. Rats (n = 6/group) inhaled 0-, 25-, 249-, or 346-ppm diacetyl for 6 hr. Tracheas and vagal ganglia were removed 1-day postexposure and labeled for substance P (SP) or protein gene product 9.5 (PGP9.5). Vagal ganglia neurons projecting to airway epithelium were identified by axonal transport of fluorescent microspheres intratracheally instilled 14 days before diacetyl inhalation. End points were SP and PGP9.5 nerve fiber density (NFD) in tracheal epithelium and SP-positive neurons projecting to the trachea. PGP9.5-immunoreactive NFD decreased in foci with denuded epithelium, suggesting loss of airway sensory innervation. However, in the intact epithelium adjacent to denuded foci, SP-immunoreactive NFD increased from 0.01 ± 0.002 in controls to 0.05 ± 0.01 after exposure to 346-ppm diacetyl. In vagal ganglia, SP-positive airway neurons increased from 3.3 ± 3.0% in controls to 25.5 ± 6.6% after inhaling 346-ppm diacetyl. Thus, diacetyl inhalation increases SP levels in sensory nerves of airway epithelium. Because SP release in airways promotes inflammation and activation of sensory nerves mediates reflexes, neural changes may contribute to flavorings-related lung disease pathogenesis. PMID:23847039

  17. Neurology: an ancient sensory organ in crocodilians.

    PubMed

    Soares, Daphne

    2002-05-16

    Crocodilians hunt at night, waiting half-submerged for land-bound prey to disturb the water surface. Here I show that crocodilians have specialized sensory organs on their faces that can detect small disruptions in the surface of the surrounding water, and which are linked to a dedicated, hypertrophied nerve system. Such 'dome' pressure receptors are also evident in fossils from the Jurassic period, indicating that these semi-aquatic predators solved the problem of combining armour with tactile sensitivity many millions of years ago. PMID:12015589

  18. Diagnosis of Severe Carpal Tunnel Syndrome Using Nerve Conduction Study and Ultrasonography.

    PubMed

    Fujimoto, Kazuhiro; Kanchiku, Tsukasa; Kido, Kenji; Imajo, Yasuaki; Funaba, Masahiro; Taguchi, Toshihiko

    2015-10-01

    This study investigated the correlation between nerve conduction study and ultrasonographic findings for assessment of the usefulness of ultrasonography in determining carpal tunnel syndrome severity. Hands of adults with carpal tunnel syndrome were assessed using ultrasound and nerve conduction studies and grouped according to median nerve cross-sectional area (CSA). There were significant differences (p < 0.01) in mean median nerve CSA between controls, patients with median sensory nerve conduction velocity ?40 m/s and patients with absent sensory nerve action potential and between controls, patients with median nerve distal motor latency ?4.5 ms and patients with absent compound muscle action potentials of the abductor pollicis brevis. This is the first report to define median nerve CSA cutoff values (18 mm(2)) for determining carpal tunnel syndrome severity in patients with absent compound muscle action potentials of the abductor pollicis brevis. Median nerve CSA values below the cutoff values should prompt clinicians to consider other disorders, such as cervical compressive myelopathy. PMID:26111913

  19. Endothelin-1 induced desensitization in primary afferent neurons

    PubMed Central

    Smith, Terika P.; Smith, Sherika N.; Sweitzer, Sarah M.

    2014-01-01

    Endothelin-1 (ET-1) is a known algogen that causes acute pain and sensitization in humans and spontaneous nociceptive behaviors when injected into the periphery in rats, and is elevated during vaso-occlusive episodes (VOEs) in sickle cell disease (SCD) patients. Previously, our lab has shown that a priming dose of ET-1 produces sensitization to capsaicin-induce secondary hyperalgesia. The goal of this study was to determine if the sensitization induced by ET-1 priming is occurring at the level of the primary afferent neuron. Calcium imaging in cultured dorsal root ganglion (DRG) neurons was utilized to examine the effects of ET-1 on primary afferent neurons. ET-1 induces [Ca2+]i transients in unprimed cells. ET-1 induced [Ca2+]i transients are attenuated by priming with ET-1. This priming effect occurs whether the priming dose is given 0-4 days prior to the challenge dose. Similarly, ET-1 priming decreases capsaicin-induced [Ca2+]i transients. At the level of the primary afferent neuron, ET-1 priming has a desensitizing effect on challenge exposures to ET-1 and capsaicin. PMID:25220703

  20. The Efficacy of Selected Desensitizing OTC Products: A Systematic Review

    PubMed Central

    Talioti, E.; Hill, R.; Gillam, D. G.

    2014-01-01

    Objectives. The aim of the present study was to review the published literature in order to identify relevant studies for inclusion and to determine whether there was any evidence on the clinical effectiveness of selected desensitizing toothpastes, calcium sodium phosphosilicate (CSPS), amorphous calcium phosphate (ACP), nanohydroxyapatite, and casein phosphopeptide-amorphous calcium phosphate (tooth mousse) on reducing dentine hypersensitivity (DH). Materials and Methods. Following a review of 593 papers identified from searching both electronic databases (PUBMED) and hand searching of relevant written journals, only 5 papers were accepted for inclusion. Results. Analysis of the included studies (3 CSPS and 2 ACP) would suggest that there may be some benefit for patients using these products for reducing DH. No direct comparative studies were available to assess all these products under the same conditions neither were there any comparative randomised controlled studies that compared at least two of these products in determining their effectiveness in treating DH. Conclusions. Due to the small number of included studies, there are limited clinical data to support any claims of clinical efficacy of these OTC products. Further studies are therefore required to determine the efficacy of these products in well-controlled RCT studies with a larger sample size. PMID:25006466

  1. beta. -Adrenergic receptor desensitization of wild-type but not cyc lymphoma cells unmasked by submillimolar Mg/sup 2 +/

    SciTech Connect

    Clark, R.B.; Friedman, J.; Johnson, J.A.; Kunkel, M.W.

    1987-10-01

    Treatment with low physiological concentrations of epinephrine (5-50 nM) rapidly desensitizes ..beta..-adrenergic stimulation of cAMP formation in S49 wild-type (WT) lymphoma cells. Previous attempts to detect this early phase desensitization in cell free assays of adenylate cyclase after intact cell treatment were unsuccessful. The authors have now found that reducing the Mg/sup 2 +/ concentrations in the adenylate cyclase assays to < 1.0 mM unmasked this rapid phase of desensitization of the WT cells, and that high Mg/sup 2 +/ concentrations (5-10 mM) largely obscured the desensitization. Submillimolar Mg/sup 2 +/ conditions also revealed a two-to-threefold decrease in the affinity of epinephrine to the ..beta..-adrenergic receptor after desensitization with 20 nM epinephrine. Detection of 4..beta..-phorbol 12-myristate 13-acetate (PMA) desensitization of the WT ..beta..-adrenergic receptor was also dependent on low Mg/sup 2 +/ as measured either by the decrease in epinephrine stimulation of adenylate cyclase or by the reduction in the affinity of epinephrine binding. Unexpectedly, when cyc/sup -/ cells were pretreated with 50 nM epinephrine, the ..beta..-adrenergic stimulation of reconstituted adenylate cyclase was not desensitized. The characteristics of the Mg/sup 2 +/ effect on epinephrine- and PMA-induced desensitizations suggest a similar mechanism of action with the most likely events being phosphorylations of the ..beta..-adrenergic receptors. Their data indicate that cAMP dependent protein kinase may play a role in the desensitization caused by low epinephrine concentrations inasmuch as this phase of desensitization did not occur in the cyc/sup -/. For the PMA-induced desensitization, the phosphorylation may be mediated by protein kinase C.

  2. The spinal accessory nerve plexus, the trapezius muscle, and shoulder stabilization after radical neck cancer surgery.

    PubMed Central

    Brown, H; Burns, S; Kaiser, C W

    1988-01-01

    A clinical and anatomic study of the spinal accessory, the eleventh cranial nerve, and trapezius muscle function of patients who had radical neck cancer surgery was conducted. This study was done not only to document the indispensibility of the trapezius muscle to shoulder-girdle stability, but also to clarify the role of the eleventh cranial nerve in the variable motor and sensory changes occurring after the loss of this muscle. Seventeen male patients, 49-69 years of age, (average of 60 years of age) undergoing a total of 23 radical neck dissections were examined for upper extremity function, particularly in regard to the trapezius muscle, and for subjective signs of pain. The eleventh nerve, usually regarded as the sole motor innervation to the trapezius, was cut in 17 instances because of tumor involvement. Dissection of four fresh and 30 preserved adult cadavers helped to reconcile the motor and sensory differences in patients who had undergone loss of the eleventh nerve. The dissections and clinical observations corroborate that the trapezius is a key part of a "muscle continuum" that stabilizes the shoulder. Variations in origins and insertions of the trapezius may influence its function in different individuals. As regards the spinal accessory nerve, it is concluded that varying motor and sensory connections form a plexus with the eleventh nerve, accounting, in part, for the variations in motor innervation and function of the trapezius, as well as for a variable spectrum of sensory changes when the eleventh nerve is cut. For this reason, it is suggested that the term "spinal accessory nerve plexus" be used to refer to the eleventh nerve when it is considered in the context of radical neck cancer surgery. Images Fig. 4. Fig. 6. Fig. 7. Fig. 8. PMID:3056289

  3. Sensory Conversion Devices

    NASA Astrophysics Data System (ADS)

    Medelius, Pedro

    The human body has five basic sensory functions: touch, vision, hearing, taste, and smell. The effectiveness of one or more of these human sensory functions can be impaired as a result of trauma, congenital defects, or the normal ageing process. Converting one type of function into another, or translating a function to a different part of the body, could result in a better quality of life for a person with diminished sensorial capabilities.

  4. Albuterol-induced downregulation of Gs? accounts for pulmonary ?2-adrenoceptor desensitization in vivo

    PubMed Central

    Finney, Paul A.; Belvisi, Maria G.; Donnelly, Louise E.; Chuang, Tsu-Tshen; Mak, Judith C.W.; Scorer, Carol; Barnes, Peter J.; Adcock, Ian M.; Giembycz, Mark A.

    2000-01-01

    The aim of the present study was to develop a chronic in vivo model of pulmonary ?2-adrenoceptor desensitization and to elucidate the nature and molecular basis of this state. Subcutaneous infusion of rats with albuterol for 7 days compromised the ability of albuterol, given acutely, to protect against acetylcholine-induced bronchoconstriction. The bronchoprotective effect of prostaglandin E2, but not forskolin, was also impaired, indicating that the desensitization was heterologous and that the primary defect in signaling was upstream of adenylyl cyclase. ?2-Adrenoceptor density was reduced in lung membranes harvested from albuterol-treated animals, and this was associated with impaired albuterol-induced cyclic adenosine monophosphate (cAMP) accumulation and activation of cAMP-dependent protein kinase ex vivo. Gs? expression was reduced in the lung and tracheae of albuterol-treated rats, and cholera toxin–induced cAMP accumulation was blunted. Chronic treatment of rats with albuterol also increased cAMP phosphodiesterase activity and G protein–coupled receptor kinase-2, but the extent to which these events contributed to ?2-adrenoceptor desensitization was unclear given that forskolin was active in both groups of animals and that desensitization was heterologous. Collectively, these results indicate that albuterol effects heterologous desensitization of pulmonary Gs-coupled receptors in this model, with downregulation of Gs? representing a primary molecular etiology. PMID:10880056

  5. [Sciatic nerve intraneural perineurioma].

    PubMed

    Bonhomme, Benjamin; Poussange, Nicolas; Le Collen, Philippe; Fabre, Thierry; Vital, Anne; Lepreux, Sébastien

    2015-12-01

    Intraneural perineurioma is a benign tumor developed from the perineurium and responsible for localized nerve hypertrophy. This uncommon tumor is characterized by a proliferation of perineural cells with a "pseudo-onion bulb" pattern. We report a sciatic nerve intraneural perineurioma in a 39-year-old patient. PMID:26586011

  6. Diabetic neuropathy: structural analysis of nerve hydration by Magnetic Resonance Spectroscopy

    SciTech Connect

    Griffey, R.H.; Eaton, P.; Sibbitt, R.R.; Sibbitt, W.L. Jr.; Bicknell, J.M.

    1988-11-18

    The water content of the sural nerve of diabetic patients was quantitatively defined by magnetic resonance proton imaging as a putative reflection of activity of the aldose-reductase pathway. Thirty-nine patients were evaluated, comparing group A, symptomatic diabetic men with sensory neuropathy; group B, similarly symptomatic diabetic men treated aldose-reductase inhibition; group C, neurologically asymptomatic diabetic men; and group D, control nondiabetic men. Marked increase in hydration of the sural nerve was seen in more than half of the symptomatic diabetic patients. Two of 11 neurologically asymptomatic diabetics had increased nerve hydration, suggesting a presymptomatic alteration of the nerve. Symptomatic diabetics treated with aldose-reductase inhibitors had normal nerve water levels. Increased level of peripheral nerve water represents a new finding in diabetes mellitus. It seems to be related to aldose-reductase activity, involved in the development of neuropathy, and similar to events that occur in other target tissue in human diabetes.

  7. Trigger finger appearing as gradually increasing digital nerve disorder after surgical treatment.

    PubMed

    Tsuchie, Hiroyuki; Nishi, Tomio; Abe, Hidekazu; Takeshima, Masaaki; Shimada, Yoichi

    2013-01-01

    Trigger finger is a common disease, and operative treatments are often applied for it. Digital nerve injury is one of the complications of this surgical treatment, and paresthesia and sensory disturbance occur early after the operation. This paper presents a case of trigger finger appearing gradually as increasing digital nerve disorder after surgical treatment. In the second surgery, scar tissue covered the palmar MP joint where the A1 pulley had existed before, and palmar digital neurovascular tissue of the ulnar side was found on the inside of the scar. The ulnar digital nerve showed swelling like a neuroma, and bilateral digital nerves existed nearer to the center of the flexor pollicis longus tendon than normal digital nerves. Even when we operate on trigger finger by open release, we should create an appropriate surgical space for observation and be careful of digital nerve injury. PMID:23634312

  8. Preoperative transcutaneous electrical nerve stimulation for localizing superficial nerve paths.

    PubMed

    Natori, Yuhei; Yoshizawa, Hidekazu; Mizuno, Hiroshi; Hayashi, Ayato

    2015-12-01

    During surgery, peripheral nerves are often seen to follow unpredictable paths because of previous surgeries and/or compression caused by a tumor. Iatrogenic nerve injury is a serious complication that must be avoided, and preoperative evaluation of nerve paths is important for preventing it. In this study, transcutaneous electrical nerve stimulation (TENS) was used for an in-depth analysis of peripheral nerve paths. This study included 27 patients who underwent the TENS procedure to evaluate the peripheral nerve path (17 males and 10 females; mean age: 59.9 years, range: 18-83 years) of each patient preoperatively. An electrode pen coupled to an electrical nerve stimulator was used for superficial nerve mapping. The TENS procedure was performed on patients' major peripheral nerves that passed close to the surgical field of tumor resection or trauma surgery, and intraoperative damage to those nerves was apprehensive. The paths of the target nerve were detected in most patients preoperatively. The nerve paths of 26 patients were precisely under the markings drawn preoperatively. The nerve path of one patient substantially differed from the preoperative markings with numbness at the surgical region. During surgery, the nerve paths could be accurately mapped preoperatively using the TENS procedure as confirmed by direct visualization of the nerve. This stimulation device is easy to use and offers highly accurate mapping of nerves for surgical planning without major complications. The authors conclude that TENS is a useful tool for noninvasive nerve localization and makes tumor resection a safe and smooth procedure. PMID:26420473

  9. Evidence for Glutamate as a Neuroglial Transmitter within Sensory Ganglia

    PubMed Central

    Kung, Ling-Hsuan; Gong, Kerui; Adedoyin, Mary; Ng, Johnson; Bhargava, Aditi; Ohara, Peter T.; Jasmin, Luc

    2013-01-01

    This study examines key elements of glutamatergic transmission within sensory ganglia of the rat. We show that the soma of primary sensory neurons release glutamate when depolarized. Using acute dissociated mixed neuronal/glia cultures of dorsal root ganglia (DRG) or trigeminal ganglia and a colorimetric assay, we show that when glutamate uptake by satellite glial cells (SGCs) is inhibited, KCl stimulation leads to simultaneous increase of glutamate in the culture medium. With calcium imaging we see that the soma of primary sensory neurons and SGCs respond to AMPA, NMDA, kainate and mGluR agonists, and selective antagonists block this response. Using whole cell patch-clamp technique, inward currents were recorded from small diameter (<30 µm) DRG neurons from intact DRGs (ex-vivo whole ganglion preparation) in response to local application of the above glutamate receptor agonists. Following a chronic constriction injury (CCI) of either the inferior orbital nerve or the sciatic nerve, glutamate expression increases in the trigeminal ganglia and DRG respectively. This increase occurs in neurons of all diameters and is present in the somata of neurons with injured axons as well as in somata of neighboring uninjured neurons. These data provides additional evidence that glutamate can be released within the sensory ganglion, and that the somata of primary sensory neurons as well as SGCs express functional glutamate receptors at their surface. These findings, together with our previous gene knockdown data, suggest that glutamatergic transmission within the ganglion could impact nociceptive threshold. PMID:23844184

  10. An Evaluation of in Vivo Desensitization and Video Modeling to Increase Compliance with Dental Procedures in Persons with Mental Retardation

    ERIC Educational Resources Information Center

    Conyers, Carole; Miltenberger, Raymond G.; Peterson, Blake; Gubin, Amber; Jurgens, Mandy; Selders, Andrew; Dickinson, Jessica; Barenz, Rebecca

    2004-01-01

    Fear of dental procedures deters many individuals with mental retardation from accepting dental treatment. This study was conducted to assess the effectiveness of two procedures, in vivo desensitization and video modeling, for increasing compliance with dental procedures in participants with severe or profound mental retardation. Desensitization

  11. The Effects of Systematic Desensitization on Test-Anxious Students in an Urban Community College: Learning Theory and Applications.

    ERIC Educational Resources Information Center

    Woods, Nathaniel A.

    A study involving 97 students (79 females and 18 males) at New York City Technical College was undertaken to determine the effectiveness of desensitization in reducing test anxiety and improving grade point averages (GPAs). The study compared the GPAs of students who completed workshops using the desensitization hierarchy developed by R. Strieby…

  12. A phenotypically restricted set of primary afferent nerve fibers innervate the bone versus skin: therapeutic opportunity for treating skeletal pain.

    PubMed

    Jimenez-Andrade, Juan Miguel; Mantyh, William G; Bloom, Aaron P; Xu, Haili; Ferng, Alice S; Dussor, Gregory; Vanderah, Todd W; Mantyh, Patrick W

    2010-02-01

    Although musculoskeletal pain is one of the most common causes of chronic pain and physical disability in both developing and developed countries, relatively little is known about the nerve fibers and mechanisms that drive skeletal pain. Small diameter sensory nerve fibers, most of which are C-fiber nociceptors, can be separated into two broad populations: the peptide-rich and peptide-poor nerve fibers. Peptide-rich nerve fibers express substance P (SP) and calcitonin gene-related peptide (CGRP). In contrast, the peptide-poor nerve fibers bind to isolectin B4 (IB(4)) and express the purinergic receptor P(2)X(3) and Mas-related G protein-coupled receptor member d (Mrgprd). In the present report, we used mice in which the Mrgprd(+) nerve fibers express genetically encoded axonal tracers to determine the peptide-rich and peptide-poor sensory nerve fibers that innervate the glabrous skin of the hindpaw as compared to the bone marrow, mineralized bone and periosteum of the femur. Whereas the skin is richly innervated by CGRP(+), SP(+), P(2)X(3)(+) and Mrgprd(+) sensory nerve fibers, the bone marrow, mineralized bone and periosteum receive a significant innervation by SP(+) and CGRP(+), but not Mrgprd(+) and P(2)X(3)(+) nerve fibers. This lack of redundancy in the populations of C-fibers that innervate the bone may present a unique therapeutic opportunity for targeting skeletal pain as the peptide-rich and peptide-poor sensory nerve fibers generally express a different repertoire of receptors and channels to detect noxious stimuli. Thus, therapies that target the specific types of C-nerve fibers that innervate the bone may be uniquely effective in attenuating skeletal pain as compared to skin pain. PMID:19766746

  13. Peripheral nerve tumours: 30-year experience in the surgical treatment.

    PubMed

    Gosk, Jerzy; Gutkowska, Olga; Mazurek, Piotr; Koszewicz, Magdalena; Zió?kowski, Piotr

    2015-07-01

    Peripheral nerve tumours are relatively rare type of soft tissue tumours. The aim of this work is to present our experience with surgical treatment of this type of lesions. Clinical material consists of 94 patients (56 females, 38 males), in whom 101 tumours deriving from peripheral nervous system were removed. The patients underwent surgical treatment between 1983 and 2012. Tumours occurred mainly in the upper extremity (72 tumours), less often in the lower extremity (25 tumours). Lesions developed in major peripheral nerves (51 tumours) and small nerve branches (50 tumours). The most common symptoms reported before surgery included presence of tumour mass (100 %), positive Hoffmann-Tinel sign (95.6 %) and paraesthesia (93.4 %). Less often sensory deficit (89.1 %) and pain (71.7 %) were observed. Motor deficit was the least common manifestation (41.3 %). Benign tumours prevailed in presented material (94 tumours). In 7 cases, malignant peripheral nerve sheath tumour (MPNST) was identified. As a result of surgical treatment in the group of tumours deriving from major peripheral nerves, in 87.8 % of the patients, pain relief was achieved; in 84 %, Hoffmann-Tinel sign was negative; and in 79 %, paraesthesia resolved. Sensory function improvement was observed in 51.2 % of the patients while motor function improved in 26.3 % of the patients. None of the patients experienced tumour relapse. In the group of tumours deriving from small nerve branches, 47 patients had no signs of tumour recurrence. One female patient diagnosed with MPNST suffered a relapse. Obtaining satisfactory results of peripheral nerve tumour treatment requires both careful differential diagnosis and well thought-out strategy at every stage of therapeutic management. PMID:25727458

  14. Tolerance of cranial nerves of the cavernous sinus to radiosurgery

    SciTech Connect

    Tishler, R.B.; Loeffler, J.S.; Alexander, E. III; Kooy, H.M. ); Lunsford, L.D.; Duma, C.; Flickinger, J.C. )

    1993-09-20

    Stereotactic radiosurgery is becoming a more accepted treatment option for benign, deep seated intracranial lesions. However, little is known about the effects of large single fractions of radiation on cranial nerves. This study was undertaken to assess the effect of radiosurgery on the cranial nerves of the cavernous sinus. The authors examined the tolerance of cranial nerves (II-VI) following radiosurgery for 62 patients (42/62 with meningiomas) treated for lesions within or near the cavernous sinus. Twenty-nine patients were treated with a modified 6 MV linear accelerator (Joint Center for Radiation Therapy) and 33 were treated with the Gamma Knife (University of Pittsburgh). Three-dimensional treatment plans were retrospectively reviewed and maximum doses were calculated for the cavernous sinus and the optic nerve and chiasm. Median follow-up was 19 months (range 3-49). New cranial neuropathies developed in 12 patients from 3-41 months following radiosurgery. Four of these complications involved injury to the optic system and 8 (3/8 transient) were the result of injury to the sensory or motor nerves of the cavernous sinus. There was no clear relationship between the maximum dose to the cavernous sinus and the development of complications for cranial nerves III-VI over the dose range used (1000-4000 cGy). For the optic apparatus, there was a significantly increased incidence of complications with dose. Four of 17 patients (24%) receiving greater than 800 cGy to any part of the optic apparatus developed visual complications compared with 0/35 who received less than 800 cGy (p = 0.009). Radiosurgery using tumor-controlling doses of up to 4000 cGy appears to be a relatively safe technique in treating lesions within or near the sensory and motor nerves (III-VI) of the cavernous sinus. The dose to the optic apparatus should be limited to under 800 cGy. 21 refs., 4 tabs.

  15. Digital innervation patterns following median or ulnar nerve laceration and their correlation to anatomic variations of the communicating branch between these nerves.

    PubMed

    Don Griot, J Peter W; Hage, J Joris; De Groot, Peter J M

    2004-08-01

    The midline of the ring finger is classically considered as the neural watershed between the median and ulnar nerve sensory territories on the palmar surfaces of the fingers. Variations of this division exist and may be explained by a communicating branch between the third and fourth common digital nerves. The palmar sensibility patterns of fingers were assessed with Semmes Weinstein filaments after either a complete median or an ulnar nerve transection in 43 patients. Eight out of nine observed sensibility patterns could be explained by known anatomic types and subtypes of the communicating branch. The type of communicating branch, but not its subtype, could be established in the one remaining pattern. PMID:15234498

  16. NEUROPHYSIOLOGICAL EVALUATION OF SENSORY SYSTEMS'

    EPA Science Inventory

    Exposure to many neurotoxic compounds has been shown to produce a sensory system dysfunction. Neurophysiological assessment of sensory function in humans and animal models often uses techniques known as sensory evoked potentials. Because both humans and animals show analogous res...

  17. Sensory Correlations in Autism

    ERIC Educational Resources Information Center

    Kern, Janet K.; Trivedi, Madhukar H.; Grannemann, Bruce D.; Garver, Carolyn R.; Johnson, Danny G.; Andrews, Alonzo A.; Savla, Jayshree S.; Mehta, Jyutika A.; Schroeder, Jennifer L.

    2007-01-01

    This study examined the relationship between auditory, visual, touch, and oral sensory dysfunction in autism and their relationship to multisensory dysfunction and severity of autism. The Sensory Profile was completed on 104 persons with a diagnosis of autism, 3 to 56 years of age. Analysis showed a significant correlation between the different…

  18. Dermatological and immunological conditions due to nerve lesions

    PubMed Central

    Bove, Domenico; Lupoli, Amalia; Caccavale, Stefano; Piccolo, Vincenzo; Ruocco, Eleonora

    2013-01-01

    Summary Some syndromes are of interest to both neurologists and dermatologists, because cutaneous involvement may harbinger symptoms of a neurological disease. The aim of this review is to clarify this aspect. The skin, because of its relationships with the peripheral sensory nervous system, autonomic nervous system and central nervous system, constitutes a neuroimmunoendocrine organ. The skin contains numerous neuropeptides released from sensory nerves. Neuropeptides play a precise role in cutaneous physiology and pathophysiology, and in certain skin diseases. A complex dysregulation of neuropeptides is a feature of some diseases of both dermatological and neurological interest (e.g. cutaneous and nerve lesions following herpes zoster infection, cutaneous manifestations of carpal tunnel syndrome, trigeminal trophic syndrome). Dermatologists need to know when a patient should be referred to a neurologist and should consider this option in those presenting with syndromes of unclear etiology. PMID:24125557

  19. Electromechanical tactile stimulation system for sensory vision substitution

    NASA Astrophysics Data System (ADS)

    Zalevsky, Zeev; Elani, Gal; Azoulay, Eli; Ilani, Dan; Beiderman, Yevgeny; Belkin, Michael

    2013-02-01

    A sensory substitution device is developed in which nonretinal stimulus is used to generate input to the brain of blind people to substitute for damage or loss of retinal input. Although the final realization of this technology (direct stimulation of the corneal nerve endings) was not addressed, a device consisting of a contact lens delivering point mechanical or electrical stimulating of the corneal nerves and a camera mounted on a spectacles frame which wirelessly transmit processed image to the contact lens, translating the visual information into tactile sensation is expected to be constructed. In order to improve the spatial resolution of the constructed image, the camera will also time multiplex, compress and encode the captured image before transmitting it to the stimulating contact lens. Preliminary devices performing tactile stimulation of the fingers and of the tongue by applying point electrical stimulations, were constructed and tested. Subjects were taught to "see" using the mechanical and the electrical tactile sensory.

  20. [Two cases of hereditary motor and sensory neuropathy with proximal dominant involvement (HMSN-P)].

    PubMed

    Mori, Chiaki; Saito, Tomoko; Saito, Toshio; Fujimura, Harutoshi; Sakoda, Saburo

    2015-01-01

    We, herein, report two independent cases with hereditary motor and sensory neuropathy with proximal dominant involvement (HMSN-P) inherited in an autosomal dominant fashion. Their common clinical features are slowly progressive proximal dominant muscular atrophy, fasciculations and mild to moderate distal sensory disturbance with areflexia. Nerve conduction study revealed an absence of sensory nerve action potentials, in contrast to almost normal compound muscle action potentials. Gene analysis in both patients elucidated heterozygous mutation (c.854C>T, p.Pro285Leu) in the TFG, which is an identical mutation, already described by Ishiura et al. Okinawa and Shiga are two foci of HMSN-P in Japan. Eventually, one patient is from Okinawa and the other is from a mountain village in Shiga prefecture. When we see a patient who has symptoms suggestive of motor neuron disease with sensory neuropathy, HMSN-P should be considered as a differential diagnosis despite the patient's actual resident place. PMID:26103812

  1. Brain Mass and Cranial Nerve Size in Shrews and Moles

    PubMed Central

    Leitch, Duncan B.; Sarko, Diana K.; Catania, Kenneth C.

    2014-01-01

    We investigated the relationship between body size, brain size, and fibers in selected cranial nerves in shrews and moles. Species include tiny masked shrews (S. cinereus) weighing only a few grams and much larger mole species weighing up to 90 grams. It also includes closely related species with very different sensory specializations – such as the star-nosed mole and the common, eastern mole. We found that moles and shrews have tiny optic nerves with fiber counts not correlated with body or brain size. Auditory nerves were similarly small but increased in fiber number with increasing brain and body size. Trigeminal nerve number was by far the largest and also increased with increasing brain and body size. The star-nosed mole was an outlier, with more than twice the number of trigeminal nerve fibers than any other species. Despite this hypertrophied cranial nerve, star-nosed mole brains were not larger than predicted from body size, suggesting that magnification of their somatosensory systems does not result in greater overall CNS size. PMID:25174995

  2. Brain mass and cranial nerve size in shrews and moles.

    PubMed

    Leitch, Duncan B; Sarko, Diana K; Catania, Kenneth C

    2014-01-01

    We investigated the relationship between body size, brain size, and fibers in selected cranial nerves in shrews and moles. Species include tiny masked shrews (S. cinereus) weighing only a few grams and much larger mole species weighing up to 90 grams. It also includes closely related species with very different sensory specializations - such as the star-nosed mole and the common, eastern mole. We found that moles and shrews have tiny optic nerves with fiber counts not correlated with body or brain size. Auditory nerves were similarly small but increased in fiber number with increasing brain and body size. Trigeminal nerve number was by far the largest and also increased with increasing brain and body size. The star-nosed mole was an outlier, with more than twice the number of trigeminal nerve fibers than any other species. Despite this hypertrophied cranial nerve, star-nosed mole brains were not larger than predicted from body size, suggesting that magnification of their somatosensory systems does not result in greater overall CNS size. PMID:25174995

  3. Diabetic Nerve Problems

    MedlinePLUS

    ... the wrong times. This damage is called diabetic neuropathy. Over half of people with diabetes get it. ... change positions quickly Your doctor will diagnose diabetic neuropathy with a physical exam and nerve tests. Controlling ...

  4. Degenerative Nerve Diseases

    MedlinePLUS

    Degenerative nerve diseases affect many of your body's activities, such as balance, movement, talking, breathing, and heart function. Many of these diseases are genetic. Sometimes the cause is a medical ...

  5. Vagus Nerve Stimulation

    PubMed Central

    Howland, Robert H.

    2014-01-01

    The vagus nerve is a major component of the autonomic nervous system, has an important role in the regulation of metabolic homeostasis, and plays a key role in the neuroendocrine-immune axis to maintain homeostasis through its afferent and efferent pathways. Vagus nerve stimulation (VNS) refers to any technique that stimulates the vagus nerve, including manual or electrical stimulation. Left cervical VNS is an approved therapy for refractory epilepsy and for treatment resistant depression. Right cervical VNS is effective for treating heart failure in preclinical studies and a phase II clinical trial. The effectiveness of various forms of non-invasive transcutaneous VNS for epilepsy, depression, primary headaches, and other conditions has not been investigated beyond small pilot studies. The relationship between depression, inflammation, metabolic syndrome, and heart disease might be mediated by the vagus nerve. VNS deserves further study for its potentially favorable effects on cardiovascular, cerebrovascular, metabolic, and other physiological biomarkers associated with depression morbidity and mortality. PMID:24834378

  6. [Optic nerve disc drusen].

    PubMed

    Samoil?, O; C?lug?ru, D; C?lug?ru, M; Emese, Kaucsar

    2006-01-01

    Optic nerve head drusen represents a frequent condition, with unknown pathogenesis, mostly asymptomatic. Here, we present a patient with visual impairment, who has reacted well to anti-inflammatory and vasodilator treatment. PMID:16927754

  7. Embryonic origin of gustatory cranial sensory neurons.

    PubMed

    Harlow, Danielle E; Barlow, Linda A

    2007-10-15

    Cranial nerves VII, IX and X provide both gustatory (taste) and non-gustatory (touch, pain, temperature) innervation to the oral cavity of vertebrates. Gustatory neurons innervate taste buds and project centrally to the rostral nucleus of the solitary tract (NTS), whereas neurons providing general epithelial innervation to the oropharynx project to non-gustatory hindbrain regions, i.e., spinal trigeminal nucleus. In addition to this dichotomy in function, cranial ganglia VII, IX and X have dual embryonic origins, comprising sensory neurons derived from both cranial neural crest and epibranchial placodes. We used a fate mapping approach to test the hypothesis that epibranchial placodes give rise to gustatory neurons, whereas the neural crest generates non-gustatory cells. Placodal ectoderm or neural crest was grafted from Green Fluorescent Protein (GFP) expressing salamander embryos into unlabeled hosts, allowing us to discern the postembryonic central and peripheral projections of each embryonic neuronal population. Neurites that innervate taste buds are exclusively placodal in origin, and their central processes project to the NTS, consistent with a gustatory fate. In contrast, neural crest-derived neurons do not innervate taste buds; instead, neurites of these sensory neurons terminate as free nerve endings within the oral epithelium. Further, the majority of centrally directed fibers of neural crest neurons terminate outside the NTS, in regions that receive general epithelial afferents. Our data provide empirical evidence that embryonic origin dictates mature neuron function within cranial sensory ganglia: specifically, gustatory neurons derive from epibranchial placodes, whereas neural crest-derived neurons provide general epithelial innervation to the oral cavity. PMID:17826760

  8. Laminin-based Nanomaterials for Peripheral Nerve Tissue Engineering

    NASA Astrophysics Data System (ADS)

    Neal, Rebekah Anne

    Peripheral nerve transection occurs commonly in traumatic injury, causing motor and sensory deficits distal to the site of injury. One option for surgical repair is the nerve conduit. Conduits currently on the market are hollow tubes into which the nerve ends are sutured. Although these conduits fill the gap, they often fail due to the slow rate of regeneration over long gaps. To facilitate increased speed of regeneration and greater potential for functional recovery, the ideal conduit should provide biochemically relevant signals and physical guidance cues, thus playing an active role in peripheral nerve regeneration. In this dissertation, I fabricated laminin-1 and laminin-polycaprolactone (PCL) blend nanofibers that mimic the geometry and functionality of the peripheral nerve basement membrane. These fibers resist hydration in aqueous media and require no harsh chemical crosslinkers. Adhesion and differentiation of both neuron-like and neuroprogenitor cells is improved on laminin nanofibrous meshes over two-dimensional laminin substrates. Blend meshes with varying laminin content were characterized for composition, tensile properties, degradation rates, and bioactivity in terms of cell attachment and axonal elongation. I have established that 10% (wt) laminin content is sufficient to retain the significant neurite-promoting effects of laminin critical in peripheral nerve repair. In addition, I utilized modified collector plate design to manipulate electric field gradients during electrospinning for the fabrication of aligned nanofibers. These aligned substrates provide enhanced directional guidance cues to the regenerating axons. Finally, I replicated the clinical problem of peripheral nerve transection using a rat tibial nerve defect model for conduit implantation. When the lumens of conduits were filled with nanofiber meshes of varying laminin content and alignment, I observed significant recovery of sensory and motor function over six weeks. This recovery was supported by nerve conduction studies and electromyography which described impulse transmission, muscle stimulation, and foot twitch through the region of regeneration. These studies provide a firm foundation for the use of natural-synthetic blend electrospun nanofibers to enhance existing hollow nerve guidance conduits. The similarity in surgical technique and obvious benefit to the patient should lead to rapid translation into clinical application.

  9. Neuroepithelial circuit formed by innervation of sensory enteroendocrine cells

    PubMed Central

    Bohórquez, Diego V.; Shahid, Rafiq A.; Erdmann, Alan; Kreger, Alex M.; Wang, Yu; Calakos, Nicole; Wang, Fan; Liddle, Rodger A.

    2015-01-01

    Satiety and other core physiological functions are modulated by sensory signals arising from the surface of the gut. Luminal nutrients and bacteria stimulate epithelial biosensors called enteroendocrine cells. Despite being electrically excitable, enteroendocrine cells are generally thought to communicate indirectly with nerves through hormone secretion and not through direct cell-nerve contact. However, we recently uncovered in intestinal enteroendocrine cells a cytoplasmic process that we named neuropod. Here, we determined that neuropods provide a direct connection between enteroendocrine cells and neurons innervating the small intestine and colon. Using cell-specific transgenic mice to study neural circuits, we found that enteroendocrine cells have the necessary elements for neurotransmission, including expression of genes that encode pre-, post-, and transsynaptic proteins. This neuroepithelial circuit was reconstituted in vitro by coculturing single enteroendocrine cells with sensory neurons. We used a monosynaptic rabies virus to define the circuit’s functional connectivity in vivo and determined that delivery of this neurotropic virus into the colon lumen resulted in the infection of mucosal nerves through enteroendocrine cells. This neuroepithelial circuit can serve as both a sensory conduit for food and gut microbes to interact with the nervous system and a portal for viruses to enter the enteric and central nervous systems. PMID:25555217

  10. A Review of Eye Movement Desensitization and Reprocessing (EMDR): Research Findings and Implications for Counsellors.

    ERIC Educational Resources Information Center

    MacCluskie, Kathryn C.

    1998-01-01

    States that within the last six years a new therapeutic technique for the treatment of posttraumatic stress disorder, Eye Movement Desensitization and Reprocessing (EMDR), has emerged. Examines the strengths and weaknesses of published studies concerning EMDR, describes the nature of the debate about the efficacy of EMDR, and reviews implications…

  11. Using Eye Movement Desensitization and Reprocessing To Enhance Treatment of Couples.

    ERIC Educational Resources Information Center

    Protinsky, Howard; Sparks, Jennifer; Flemke, Kimberly

    2001-01-01

    Eye Movement Desensitization and Reprocessing (EMDR) as a clinical technique may enhance treatment effectiveness when applied in couple therapy that is emotionally and experientially oriented. Clinical experience indicates EMDR-based interventions are useful for accessing and reprocessing intense emotions in couple interactions. EMDR can amplify…

  12. Eye Movement Desensitization and Reprocessing (EMDR) Treatment for Psychologically Traumatized Individuals.

    ERIC Educational Resources Information Center

    Wilson, Sandra A.; And Others

    1995-01-01

    Studies the effects of 3 90-minute Eye Movement Desensitization and Reprocessing (EMDR) treatment sessions on traumatic memories of 80 participants. Participants receiving EMDR showed decreases in complaints and anxiety, and increases in positive cognition. Participants in the delayed-treatment condition showed no improvement in any measures in…

  13. Single expressed glycine receptor domains reconstitute functional ion channels without subunit-specific desensitization behavior.

    PubMed

    Meiselbach, Heike; Vogel, Nico; Langlhofer, Georg; Stangl, Sabine; Schleyer, Barbara; Bahnassawy, Lamia'a; Sticht, Heinrich; Breitinger, Hans-Georg; Becker, Cord-Michael; Villmann, Carmen

    2014-10-17

    Cys loop receptors are pentameric arrangements of independent subunits that assemble into functional ion channels. Each subunit shows a domain architecture. Functional ion channels can be reconstituted even from independent, nonfunctional subunit domains, as shown previously for GlyR?1 receptors. Here, we demonstrate that this reconstitution is not restricted to ?1 but can be transferred to other members of the Cys loop receptor family. A nonfunctional GlyR subunit, truncated at the intracellular TM3-4 loop by a premature stop codon, can be complemented by co-expression of the missing tail portion of the receptor. Compared with ?1 subunits, rescue by domain complementation was less efficient when GlyR?3 or the GABAA/C subunit ?1 was used. If truncation disrupted an alternative splicing cassette within the intracellular TM3-4 loop of ?3 subunits, which also regulates receptor desensitization, functional rescue was not possible. When ?3 receptors were restored by complementation using domains with and without the spliced insert, no difference in desensitization was found. In contrast, desensitization properties could even be transferred between ?1/?3 receptor chimeras harboring or lacking the ?3 splice cassette proving that functional rescue depends on the integrity of the alternative splicing cassette in ?3. Thus, an intact ?3 splicing cassette in the TM3-4 loop environment is indispensable for functional rescue, and the quality of receptor restoration can be assessed from desensitization properties. PMID:25143388

  14. Single Expressed Glycine Receptor Domains Reconstitute Functional Ion Channels without Subunit-specific Desensitization Behavior*

    PubMed Central

    Meiselbach, Heike; Vogel, Nico; Langlhofer, Georg; Stangl, Sabine; Schleyer, Barbara; Bahnassawy, Lamia'a; Sticht, Heinrich; Breitinger, Hans-Georg; Becker, Cord-Michael; Villmann, Carmen

    2014-01-01

    Cys loop receptors are pentameric arrangements of independent subunits that assemble into functional ion channels. Each subunit shows a domain architecture. Functional ion channels can be reconstituted even from independent, nonfunctional subunit domains, as shown previously for GlyR?1 receptors. Here, we demonstrate that this reconstitution is not restricted to ?1 but can be transferred to other members of the Cys loop receptor family. A nonfunctional GlyR subunit, truncated at the intracellular TM3–4 loop by a premature stop codon, can be complemented by co-expression of the missing tail portion of the receptor. Compared with ?1 subunits, rescue by domain complementation was less efficient when GlyR?3 or the GABAA/C subunit ?1 was used. If truncation disrupted an alternative splicing cassette within the intracellular TM3–4 loop of ?3 subunits, which also regulates receptor desensitization, functional rescue was not possible. When ?3 receptors were restored by complementation using domains with and without the spliced insert, no difference in desensitization was found. In contrast, desensitization properties could even be transferred between ?1/?3 receptor chimeras harboring or lacking the ?3 splice cassette proving that functional rescue depends on the integrity of the alternative splicing cassette in ?3. Thus, an intact ?3 splicing cassette in the TM3–4 loop environment is indispensable for functional rescue, and the quality of receptor restoration can be assessed from desensitization properties. PMID:25143388

  15. Accelerated Desensitization with Adaptive Attitudes and Test Gains with 5th Graders

    ERIC Educational Resources Information Center

    Miller, Melanie; Morton, Jerome; Driscoll, Richard; Davis, Kai A.

    2006-01-01

    The study evaluates an easily-administered test-anxiety reduction program. An entire fifth grade was screened, and 36 students identified as test-anxious were randomly assigned to an Intervention or a non-participant Control group. The intervention was an accelerated desensitization and adaptive attitudes (ADAA) treatment which involved…

  16. Accelerated Desensitization and Adaptive Attitudes Interventions and Test Gains with Academic Probation Students

    ERIC Educational Resources Information Center

    Driscoll, Richard; Holt, Bruce; Hunter, Lori

    2005-01-01

    The study evaluates the test-gain benefits of an accelerated desensitization and adaptive attitudes intervention for test-anxious students. College students were screened for high test anxiety. Twenty anxious students, half of them on academic probation, were assigned to an Intervention or to a minimal treatment Control group. The Intervention was…

  17. Ceftaroline Desensitization Procedure in a Pregnant Patient With Multiple Drug Allergies

    PubMed Central

    Kuhlen, James L.; Blumenthal, Kimberly G.; Sokol, Caroline L.; Balekian, Diana S.; Weil, Ana A.; Varughese, Christy A.; Shenoy, Erica S.; Banerji, Aleena

    2015-01-01

    Validated skin testing is lacking for many drugs, including ceftaroline. The cross-reactivity between ceftaroline and other ?-lactam antibiotics is unknown. We report a case of a pregnant patient with cystic fibrosis and multiple drug allergies who required ceftaroline for methicillin-resistant Staphylococcus aureus pneumonia and underwent an uncomplicated empiric desensitization procedure. PMID:26034776

  18. INJECTION FROM A TIP TRENCH AS A TURBINE TIP DESENSITIZATION METHOD

    E-print Network

    Camci, Cengiz

    CC-102 INJECTION FROM A TIP TRENCH AS A TURBINE TIP DESENSITIZATION METHOD Part 1 : Effect and instrumented to have a tip trench with discrete injection holes directed towards the pressure side. Time is about 4% greater. Coolant injection from the tip trench is successful in filling in the total pressure

  19. INJECTION FROM A TIP TRENCH AS A TURBINE TIP DESENSITIZATION METHOD

    E-print Network

    Camci, Cengiz

    CC-122 INJECTION FROM A TIP TRENCH AS A TURBINE TIP DESENSITIZATION METHOD Part 2 : Leakage flow issuing from a tip platform trench were successful in reducing the total pressure deficit due to tip revolutions. The injection holes are located at 61%, 71%, 81%, and 91% blade axial chord, in the tip trench

  20. Ethanol increases desensitization of recombinant GluR-D AMPA receptor and TARP combinations

    PubMed Central

    Möykkynen, Tommi P.; Coleman, Sarah K.; Keinänen, Kari; Lovinger, David M.; Korpi, Esa R.

    2009-01-01

    Glutamate receptors are important target molecules of the acute effect of ethanol. We studied ethanol sensitivity of homomeric GluR-D receptors expressed in HEK293 cells, and examined whether recently discovered transmembrane AMPA receptor regulatory proteins (TARPs) affect ethanol sensitivity. Co-expression of the TARPs, stargazin and ?4, increased the time constant (?-value) of current decay in the presence of agonist, thus slowing the onset of desensitization and increasing the steady-state current. Ethanol produced less inhibition of the peak current than the steady-state current for all types of the GluR-D receptors. In addition, ethanol concentration-dependently accelerated the rate of desensitization, measured as the ?-value of fast decay of peak current. This effect was enhanced with co-expression of TARPs. The recovery from desensitization was slowed down by co-expression of ?4, but ethanol did not affect this process in any GluR-D combination. The results support the idea that increased desensitization is an important mechanism in the ethanol inhibition of AMPA receptors, and indicate that co-expression of TARPs can alter this effect of ethanol. PMID:19560629

  1. Alkaline phosphatase relieves desensitization of adenylate cyclase-coupled beta-adrenergic receptors in avian erythrocyte membranes

    SciTech Connect

    Stadel, J.M.; Rebar, R.; Crooke, S.T.

    1987-05-01

    Desensitization of adenylate cyclase-coupled ..beta..-adrenergic receptors in avian erythrocytes results in 40-65% decrease in agonist-stimulated adenylate cyclase activity and correlates with increased phosphorylation of ..beta..-adrenergic receptors. To assess the role of phosphorylation in desensitization, membranes from isoproterenol- and cAMP-desensitized turkey erythrocytes were incubated with alkaline phosphatase for 30 min at 37/sup 0/C, pH = 8.0. In both cases alkaline phosphatase treatment significantly reduced desensitization of agonist-stimulated adenylate cyclase activity by 40-60%. Similar results were obtained following alkaline phosphatase treatment of membranes from isoproterenol- and cAMP-desensitized duck erythrocytes. In addition, alkaline phosphatase treatment of membranes from duck erythrocytes desensitized with phorbol 12-mystrate 13-acetate returned adenylate cyclase activity to near control values. In all experiments inclusion of 20 mM NaPO/sub 4/ to inhibit alkaline phosphatase during treatment of membranes blocked the enzyme's effect on agonist-stimulated adenylate cyclase activity. These results demonstrate a role for phosphorylation in desensitization of adenylate cyclase-coupled ..beta..-adrenergic receptors in avian erythrocytes.

  2. Carboxyl-terminal domain of transient receptor potential vanilloid 1 contains distinct segments differentially involved in capsaicin- and heat-induced desensitization.

    PubMed

    Joseph, John; Wang, Sen; Lee, Jongseok; Ro, Jin Y; Chung, Man-Kyo

    2013-12-13

    Multiple Ca(2+)-dependent processes are involved in capsaicin-induced desensitization of transient receptor potential vanilloid 1 (TRPV1), but desensitization of TRPV1 by heat occurs even in the absence of extracellular Ca(2+), although the mechanisms are unknown. In this study, we tested the hypothesis that capsaicin and heat desensitize TRPV1 through distinct mechanisms involving distinct structural segments of TRPV1. In HEK293 cells that heterologously express TRPV1, we found that heat-induced desensitization was not affected by the inclusion of intracellular ATP or alanine mutation of Lys(155), both of which attenuate capsaicin-induced desensitization, suggesting that heat-induced desensitization occurs through mechanisms distinct from capsaicin-induced desensitization. To determine protein domains involved in heat-induced desensitization, we generated chimeric proteins between TRPV1 and TRPV3, a heat-gated channel lacking heat-induced desensitization. We found that TRPV1 with the carboxyl-terminal domain (CTD) of TRPV3 retained heat activation but was impaired in heat-induced desensitization. Further experiments using chimeric or deletion mutants within TRPV1 CTD indicated that the distal half of CTD regulates the activation and desensitization of TRPV1 in modality-specific manners. Within the distal CTD, we identified two segments that distinctly regulated capsaicin- and heat-induced desensitization. The results suggest that the activation and desensitization of TRPV1 by capsaicin and heat can be modulated differentially and disproportionally through different regions of TRPV1 CTD. Identifying the domains involved in thermal regulation of TRPV1 may facilitate the development of novel anti-hyperalgesic approaches aimed at attenuating activation and enhancing desensitization of TRPV1 by thermal stimuli. PMID:24174527

  3. Carboxyl-terminal Domain of Transient Receptor Potential Vanilloid 1 Contains Distinct Segments Differentially Involved in Capsaicin- and Heat-induced Desensitization*

    PubMed Central

    Joseph, John; Wang, Sen; Lee, Jongseok; Ro, Jin Y.; Chung, Man-Kyo

    2013-01-01

    Multiple Ca2+-dependent processes are involved in capsaicin-induced desensitization of transient receptor potential vanilloid 1 (TRPV1), but desensitization of TRPV1 by heat occurs even in the absence of extracellular Ca2+, although the mechanisms are unknown. In this study, we tested the hypothesis that capsaicin and heat desensitize TRPV1 through distinct mechanisms involving distinct structural segments of TRPV1. In HEK293 cells that heterologously express TRPV1, we found that heat-induced desensitization was not affected by the inclusion of intracellular ATP or alanine mutation of Lys155, both of which attenuate capsaicin-induced desensitization, suggesting that heat-induced desensitization occurs through mechanisms distinct from capsaicin-induced desensitization. To determine protein domains involved in heat-induced desensitization, we generated chimeric proteins between TRPV1 and TRPV3, a heat-gated channel lacking heat-induced desensitization. We found that TRPV1 with the carboxyl-terminal domain (CTD) of TRPV3 retained heat activation but was impaired in heat-induced desensitization. Further experiments using chimeric or deletion mutants within TRPV1 CTD indicated that the distal half of CTD regulates the activation and desensitization of TRPV1 in modality-specific manners. Within the distal CTD, we identified two segments that distinctly regulated capsaicin- and heat-induced desensitization. The results suggest that the activation and desensitization of TRPV1 by capsaicin and heat can be modulated differentially and disproportionally through different regions of TRPV1 CTD. Identifying the domains involved in thermal regulation of TRPV1 may facilitate the development of novel anti-hyperalgesic approaches aimed at attenuating activation and enhancing desensitization of TRPV1 by thermal stimuli. PMID:24174527

  4. Desensitization of ETA endothelin receptor-mediated negative chronotropic response in right atria–species difference and intracellular mechanisms

    PubMed Central

    Ono, Kageyoshi; Sakamoto, Aiji; Masaki, Tomoh; Satake, Motoyoshi

    1998-01-01

    Desensitization of ETA endothelin receptor (ETAR) was compared between the rat and guinea-pig with regard to negative chronotropic response (NC) in the right atria (RA).ET-1 (100?nM) produced distinct NC in the presence of BQ788 (300?nM), and positive chronotropic response (PC) in the presence of BQ123 (1??M) in both species, showing that ETAR and ETB endothelin receptor (ETBR) mediate NC and PC, respectively.Repetitive applications of ET-1 (50?nM) desensitized PC, and the second application only induced a strong NC in both species. Later applications of ET-1 produced virtually no response in the rat RA, whereas they produced BQ123-sensitive NCs repetitively in guinea-pig RA, exhibiting marked species difference in desensitization of ETAR-mediated NC.Pretreatment with staurosporine (100?nM) prevented desensitization of ETAR in the rat RA altogether. However, phorbol 12-myristate 13-acetate (PMA, 300?nM) failed to induce, but rather hampered, desensitization of ETAR.Partial amino acid sequencing of ETARs, spanning from the 2nd through the 4th intracellular loops, revealed that all the potential Ser/Thr phosphorylation sites, including a protein kinase C (PKC) site, are conserved among guinea-pigs, rats, rabbits, bovines and humans.In guinea pig RA, pretreatment with okadaic acid (1??g?ml?1) and PMA did not facilitate desensitization of ETAR whereas these agents successfully desensitized ETAR during combined stimulation of ?-adrenoceptor and ETAR by isoproterenol (300?nM) and ET-1 (100?nM).These results suggest that species differences in desensitization of ETAR are not caused by differences in the site(s) of, but caused by differences in the environment for phosphorylation of the receptor. Desensitization of ETAR appears to require phosphorylation of the receptor by PKC as well as a kinase stimulated by ?-adrenoceptor activation. PMID:9831916

  5. Examining Sensory Quadrants in Autism

    ERIC Educational Resources Information Center

    Kern, Janet K.; Garver, Carolyn R.; Carmody, Thomas; Andrews, Alonzo A.; Trivedi, Madhukar H.; Mehta, Jyutika A.

    2007-01-01

    The purpose of this study was to examine sensory quadrants in autism based on Dunn's Theory of Sensory Processing. The data for this study was collected as part of a cross-sectional study that examined sensory processing (using the Sensory Profile) in 103 persons with autism, 3-43 years of age, compared to 103 age- and gender-matched community…

  6. Communications Between the Facial Nerve and the Vestibulocochlear Nerve, the Glossopharyngeal Nerve, and the Cervical Plexus.

    PubMed

    Hwang, Kun; Song, Ju Sung; Yang, Su Cheol

    2015-10-01

    The aim of this review is to elucidate the communications between the facial nerves or facial nerve and neighboring nerves: the vestibulocochlear nerve, the glossopharyngeal nerve, and the cervical plexus.In a PubMed search, 832 articles were searched using the terms "facial nerve and communication." Sixty-two abstracts were read and 16 full-text articles were reviewed. Among them, 8 articles were analyzed.The frequency of communication between the facial nerve and the vestibulocochlear nerve was the highest (82.3%) and the frequency of communication between the facial nerve and the glossopharyngeal nerve was the lowest (20%). The frequency of communication between the facial nerve and the cervical plexus was 65.2?±?43.5%. The frequency of communication between the cervical branch and the marginal mandibular branch of the facial nerve was 24.7?±?1.7%.Surgeons should be aware of the nerve communications, which are important during clinical examinations and surgical procedures of the facial nerves such as those communications involved in facial reconstructive surgery, neck dissection, and various nerve transfer procedures. PMID:26413963

  7. The metabotropic glutamate receptor 4 is internalized and desensitized upon protein kinase C activation

    PubMed Central

    Mathiesen, Jesper Mosolff; Ramirez, M Teresa

    2006-01-01

    The metabotropic glutamate receptor 4 (mGluR4) is a G?i-coupled receptor that modulates glutamatergic neurotransmission. As mGluR4 expression and activation have been implicated in a number of pathological conditions and because the internalization and desensitization properties of this receptor are poorly understood, studies were designed to investigate these aspects of mGluR4 biology. Neither agonist activation by L-(+)-2-amino-4-phosphonobutyric acid (L-AP4) nor L-glutamate caused mGluR4 internalization when cmyc-tagged mGluR4 was expressed in a human embryonic kidney 293 cell line as assessed by cell surface enzyme-linked immunosorbent and immunostaining assays. Instead, a modest increase in mGluR4 surface expression was observed and found to be receptor specific as the competitive antagonist ?-cyclopropyl-4-phosphonophenylglycine (CPPG) blocked this effect. In contrast, mGluR4 internalized when the protein kinase C (PKC) pathway was activated either by phorbol-12-myristate-13-acetate (PMA) or by the activation of the G?q-coupled, neurokinin 3 receptor (NK3R) when co-expressed. This process was PKC-dependent as the specific PKC inhibitor GF 109203X inhibited PMA and NK3R-mediated internalization. PKC activation by PMA caused desensitization of mGluR4 as measured by forskolin-stimulated cAMP inhibition, whereas agonist activation had no effect on desensitization. When mGluR4's coupling was redirected from adenylyl cyclase to phospholipase C by coexpression of a chimeric G?qo5 protein, mGluR4 both internalized and desensitized in response to its agonists. These findings demonstrate that mGluR4 internalization and desensitization are agonist-independent unless pathways leading to the activation of PKC are induced. PMID:16582932

  8. Benzoquinone Reveals a Cysteine-Dependent Desensitization Mechanism of TRPA1

    PubMed Central

    Ibarra, Yessenia

    2013-01-01

    The transient receptor potential ankyrin 1 (TRPA1) nonselective cation channel has a conserved function as a noxious chemical sensor throughout much of Metazoa. Electrophilic chemicals activate both insect and vertebrate TRPA1 via covalent modification of cysteine residues in the amino-terminal region. Although naturally occurring electrophilic plant compounds, such as mustard oil and cinnamaldehyde, are TRPA1 agonists, it is unknown whether arthropod-produced electrophiles activate mammalian TRPA1. We characterized the effects of the electrophilic arthropod defensive compound para-benzoquinone (pBQN) on the human TRPA1 channel. We used whole-cell recordings of human embryonic kidney cells heterologously expressing either wild-type TRPA1 or TRPA1 with three serine-substituted cysteines crucial for electrophile activation (C621S, C641S, C665S). We found that pBQN activates TRPA1 starting at 10 nM and peaking at 300 nM; higher concentrations caused rapid activation followed by a fast decline. Activation by pBQN required reactivity with cysteine residues, but ones that are distinct from those previously reported to be the key targets of electrophiles. The current reduction we found at higher pBQN concentrations was a cysteine-dependent desensitization of TRPA1, and did not require prior activation. The cysteines required for desensitization are not accessible to all electrophiles as iodoacetamide and internally applied 2-(trimethylammonium)ethyl methanesulfonate failed to cause desensitization (despite large activation). Interestingly, following pBQN desensitization, wild-type TRPA1 had dramatically reduced response to the nonelectrophile agonist carvacrol, whereas the triple cysteine mutant TRPA1 retained its full response. Our results suggest that modification of multiple cysteine residues by electrophilic compounds can generate both activation and desensitization of the TRPA1 channel. PMID:23478802

  9. A new type of functional chemical sensitizer {MgH}2 for improving pressure desensitization resistance of emulsion explosives

    NASA Astrophysics Data System (ADS)

    Cheng, Y. F.; Yan, S. L.; Ma, H. H.; Shen, Z. W.; Liu, R.

    2015-07-01

    In millisecond-delay blasting and deep water blasting projects, traditional emulsion explosives sensitized by the chemical sensitizer NaNO2 often encounter incomplete explosion or misfire problems because of the "pressure desensitization" phenomenon, which seriously affects blasting safety and construction progress. A MgH2 -sensitized emulsion explosive was invented to solve these problems. Experimental results show that MgH2 can effectively reduce the problem of pressure desensitization. In this paper, the factors which influence the pressure desensitization of two types of emulsion explosives are studied, and resistance to this phenomenon of MgH2 -sensitized emulsion explosives is discussed.

  10. Regulation of early and delayed radiation responses in rat small intestine by capsaicin-sensitive nerves

    SciTech Connect

    Wang Junru; Zheng Huaien; Kulkarni, Ashwini; Ou Xuemei; Hauer-Jensen, Martin . E-mail: mhjensen@life.uams.edu

    2006-04-01

    Purpose: Mast cells protect against the early manifestations of intestinal radiation toxicity, but promote chronic intestinal wall fibrosis. Intestinal sensory nerves are closely associated with mast cells, both anatomically and functionally, and serve an important role in the regulation of mucosal homeostasis. This study examined the effect of sensory nerve ablation on the intestinal radiation response in an established rat model. Methods and Materials: Rats underwent sensory nerve ablation with capsaicin or sham ablation. Two weeks later, a localized segment of ileum was X-irradiated or sham irradiated. Structural, cellular, and molecular changes were examined 2 weeks (early injury) and 26 weeks (chronic injury) after irradiation. The mast cell dependence of the effect of sensory nerve ablation on intestinal radiation injury was assessed using c-kit mutant (Ws/Ws) mast cell-deficient rats. Results: Capsaicin treatment caused a baseline reduction in mucosal mast cell density, crypt cell proliferation, and expression of substance P and calcitonin gene-related peptide, two neuropeptides released by sensory neurons. Sensory nerve ablation strikingly exacerbated early intestinal radiation toxicity (loss of mucosal surface area, inflammation, intestinal wall thickening), but attenuated the development of chronic intestinal radiation fibrosis (collagen I accumulation and transforming growth factor {beta} immunoreactivity). In mast cell-deficient rats, capsaicin treatment exacerbated postradiation epithelial injury (loss of mucosal surface area), but none of the other aspects of radiation injury were affected by capsaicin treatment. Conclusions: Ablation of capsaicin-sensitive enteric neurons exacerbates early intestinal radiation toxicity, but attenuates development of chronic fibroproliferative changes. The effect of capsaicin treatment on the intestinal radiation response is partly mast cell dependent.

  11. Feeding-dependent activation of enteric cells and sensory neurons by lymphatic fluid: evidence for a neurolymphocrine system

    PubMed Central

    Poole, Daniel P.; Lee, Mike; Tso, Patrick; Bunnett, Nigel W.; Yo, Sek Jin; Lieu, TinaMarie; Shiu, Amy; Wang, Jen-Chywan; Nomura, Daniel K.

    2014-01-01

    Lymphatic fluid is a plasma filtrate that can be viewed as having biological activity through the passive accumulation of molecules from the interstitial fluid. The possibility that lymphatic fluid is part of an active self-contained signaling process that parallels the endocrine system, through the activation of G-protein coupled receptors (GPCR), has remained unexplored. We show that the GPCR lysophosphatidic acid 5 (LPA5) is found in sensory nerve fibers expressing calcitonin gene-related peptide (CGRP) that innervate the lumen of lymphatic lacteals and enteric nerves. Using LPA5 as a model for nutrient-responsive GPCRs present on sensory nerves, we demonstrate that dietary protein hydrolysate (peptone) can induce c-Fos expression in enterocytes and nerves that express LPA5. Mesenteric lymphatic fluid (MLF) mobilizes intracellular calcium in cell models expressing LPA5 upon feeding in a time- and dose-dependent manner. Primary cultured neurons of the dorsal root ganglia expressing CGRP are activated by MLF, which is enhanced upon LPA5 overexpression. Activation is independent of the known LPA5 agonists, lysophosphatidic acid and farnesyl pyrophosphate. These data bring forth a pathway for the direct stimulation of sensory nerves by luminal contents and interstitial fluid. Thus, by activating LPA5 on sensory nerves, MLF provides a means for known and yet to be identified constituents of the interstitial fluid to act as signals to comprise a “neurolymphocrine” system. PMID:24578341

  12. Sympathetic and sensory innervation of small intensely fluorescent (SIF) cells in rat superior cervical ganglion.

    PubMed

    Takaki, Fumiya; Nakamuta, Nobuaki; Kusakabe, Tatsumi; Yamamoto, Yoshio

    2015-02-01

    The sympathetic ganglion contains small intensely fluorescent (SIF) cells derived from the neural crest. We morphologically characterize SIF cells and focus on their relationship with ganglionic cells, preganglionic nerve fibers and sensory nerve endings. SIF cells stained intensely for tyrosine hydroxylase (TH), with a few cells also being immunoreactive for dopamine ?-hydroxylase (DBH). Vesicular acetylcholine transporter (VAChT)-immunoreactive puncta were distributed around some clusters of SIF cells, whereas some SIF cells closely abutted DBH-immunoreactive ganglionic cells. SIF cells contained bassoon-immunoreactive products beneath the cell membrane at the attachments and on opposite sites to the ganglionic cells. Ganglion neurons and SIF cells were immunoreactive to dopamine D2 receptors. Immunohistochemistry for P2X3 revealed ramified nerve endings with P2X3 immunoreactivity around SIF cells. Triple-labeling for P2X3, TH and VAChT allowed the classification of SIF cells into three types based on their innervation: (1) with only VAChT-immunoreactive puncta, (2) with only P2X3-immunoreactive nerve endings, (3) with both P2X3-immunoreactive nerve endings and VAChT-immunoreactive puncta. The results of retrograde tracing with fast blue dye indicated that most of these nerve endings originated from the petrosal ganglion. Thus, SIF cells in the superior cervical ganglion are innervated by preganglionic fibers and glossopharyngeal sensory nerve endings and can be classified into three types. SIF cells might modulate sympathetic activity in the superior cervical ganglion. PMID:25416508

  13. Terminal nerve and vision.

    PubMed

    Behrens, U; Wagner, H-J

    2004-09-01

    The vertebrate retina receives efferent input from different parts of the central nervous system. Efferent fibers are thought to influence retinal information processing but their functional role is not well understood. One of the best-described retinopetal fiber systems in teleost retinae belongs to the terminal nerve complex. Gonadotropin-releasing hormone (GnRH) and molluscan cardioexcitatory tetrapeptide (FMRFamide)-containing fibers from the ganglion of the terminal nerve form a dense fiber plexus in the retina at the border of the inner nuclear and inner plexiform layer. Peptide-containing fibers surround and contact perikarya of dopaminergic interplexiform cells in teleost retina. In vitro experiments demonstrated that exogenously supplied GnRH mediates dopaminergic effects on the membrane potential and on the morphology of dendritic tips (spinules) of cone horizontal cells. These effects can be specifically blocked by GnRH-antagonists, indicating that the release of dopamine and dopamine-dependent effects on light adaptation of retinal neurons are affected by the terminal nerve complex. Recent data have shown that olfactory information has an impact on retinal physiology, but its precise role is not clear. The efferent fiber of the terminal nerve complex is one of the first retinopetal fiber systems for which the sources of the fibers, their cellular targets, and several physiological, morphological, and behavioral effects are known. The terminal nerve complex is therefore a model system for the analysis of local information processing which is influenced by a distinct fiber projection. PMID:15570588

  14. Capsaicin and sensory neurones: a historical perspective.

    PubMed

    Szolcsányi, János

    2014-01-01

    Capsaicin, the pungent ingredient of red pepper has become not only a "hot" topic in neuroscience but its new target-related unique actions have opened the door for the drug industry to introduce a new chapter of analgesics. After several lines of translational efforts with over 1,000 patents and clinical trials, the 8% capsaicin dermal patch reached the market and its long-lasting local analgesic effect in some severe neuropathic pain states is now well established. This introductory chapter outlines on one hand the historical background based on the author's 50 years of experience in this field and on the other hand emphasizes new scopes, fascinating perspectives in pharmaco-physiology, and molecular pharmacology of nociceptive sensory neurons. Evidence for the effect of capsaicin on C-polymodal nociceptors (CMH), C-mechanoinsensitive (CHMi), and silent C-nociceptors are listed and the features of the capsaicin-induced blocking effects of nociceptors are demonstrated. Common and different characteristics of nociceptor-blocking actions after systemic, perineural, local, intrathecal, and in vitro treatments are summarized. Evidence for the misleading conclusions drawn from neonatal capsaicin pretreatment is presented. Perspectives opened from cloning the capsaicin receptor "Transient Receptor Potential Vanilloid 1" (TRPV1) are outlined and potential molecular mechanisms behind the long-lasting functional, ultrastructural, and nerve terminal-damaging effects of capsaicin and other TRPV1 agonists are summarized. Neurogenic inflammation and the long-list of "capsaicin-sensitive" tissue responses are mediated by an unorthodox dual sensory-efferent function of peptidergic TRPV1-expressing nerve terminals which differ from the classical efferent and sensory nerve endings that have a unidirectional role in neuroregulation. Thermoregulatory effects of capsaicin are discussed in detail. It is suggested that since hyperthermia and burn risk due to enhanced noxious heat threshold are the major obstacles of some TRPV1 antagonists, they could be overcome. The special "multisteric" gating function of the TRPV1 cation channel provides the structural ground for blocking chemical activation of TRPV1 without affecting its responsiveness to physical stimuli. A new chapter of potential analgesics targeting nociceptors is now already supported for pain relief in persistent pathological pain states. PMID:24941663

  15. Use of axonal projection patterns for the homologisation of cerebral nerves in Opisthobranchia, Mollusca and Gastropoda

    PubMed Central

    2013-01-01

    Introduction Gastropoda are guided by several sensory organs in the head region, referred to as cephalic sensory organs (CSOs). These CSOs are innervated by distinct nerves. This study proposes a unified terminology for the cerebral nerves and the categories of CSOs and then investigates the neuroanatomy and cellular innervation patterns of these cerebral nerves, in order to homologise them. The homologisation of the cerebral nerves in conjunction with other data, e.g. ontogenetic development or functional morphology, may then provide insights into the homology of the CSOs themselves. Results Nickel-lysine axonal tracing (“backfilling”) was used to stain the somata projecting into specific nerves in representatives of opisthobranch Gastropoda. Tracing patterns revealed the occurrence, size and relative position of somata and their axons and enabled these somata to be mapped to specific cell clusters. Assignment of cells to clusters followed a conservative approach based primarily on relative location of the cells. Each of the four investigated cerebral nerves could be uniquely identified due to a characteristic set of soma clusters projecting into the respective nerves via their axonal pathways. Conclusions As the described tracing patterns are highly conserved morphological characters, they can be used to homologise nerves within the investigated group of gastropods. The combination of adequate number of replicates and a comparative approach allows us to provide preliminary hypotheses on homologies for the cerebral nerves. Based on the hypotheses regarding cerebral nerve homology together with further data on ultrastructure and immunohistochemistry of CSOs published elsewhere, we can propose preliminary hypotheses regarding homology for the CSOs of the Opisthobranchia themselves. PMID:23597272

  16. Imaging of intracellular calcium during desensitization of nicotinic acetylcholine receptors of rat chromaffin cells

    PubMed Central

    Khiroug, L; Giniatullin, R; Sokolova, Elena; Talantova, Maria; Nistri, A

    1997-01-01

    The possible role of intracellular Ca2+ levels ([Ca2+]i) in desensitization of nicotinic acetylcholine receptors (AChRs) was investigated in rat cultured chromaffin cells by use of combined whole-cell patch clamping and confocal laser scanning microscopy with the fluorescent dye fluo-3.On cells held at ?70?mV, pressure-application of nicotine elicited inward currents with associated [Ca2+]i rises mainly due to influx through nicotinic AChRs. These responses were blocked by (+)-tubocurarine (10??M) but were insensitive to ?-bungarotoxin (1??M) or Cd2+ (0.1?mM).Pressure applications of 1?mM nicotine for 2?s (conditioning pulse) evoked inward currents which faded biexponentially to a steady state level due to receptor desensitization and were accompanied by a sustained increase in [Ca2+]i. Inward currents evoked by subsequent application of brief test pulses of nicotine were depressed but recovered with a time course reciprocal to the decay of the [Ca2+]i transient induced by the conditioning pulse.Omission of intracellular Ca2+ chelators or use of high extracellular Ca2+ solution (10?mM) lengthened recovery of nicotinic AChRs from desensitization while adding BAPTA or EGTA intracellularly had the opposite effect. When the patch pipette contained fluo-3 or no chelators, after establishing whole cell conditions the rate of recovery became progressively longer presumably due to dialysis of endogenous Ca2+ buffers. None of these manipulations of external or internal Ca2+ had any effect on onset or steady state level of desensitization.High spatial resolution imaging of [Ca2+]i in intact cells (in the presence of 0.1?mM Cd2+) showed that its level in the immediate submembrane area decayed at the same rate as in the rest of the cell, indicating that Ca2+ was in a strategic location to modulate (directly or indirectly) AChR desensitization.The present data suggest that desensitized nicotinic AChRs are stabilized in their conformation by raised [Ca2+]i and that this phenomenon retards their recovery to full activity. PMID:9421278

  17. Femoral nerve regeneration and its accuracy under different injury mechanisms

    PubMed Central

    Aikeremujiang·Muheremu; Ao, Qiang; Wang, Yu; Cao, Peng; Peng, Jiang

    2015-01-01

    Surgical accuracy has greatly improved with the advent of microsurgical techniques. However, complete functional recovery after peripheral nerve injury has not been achieved to date. The mechanisms hindering accurate regeneration of damaged axons after peripheral nerve injury are in urgent need of exploration. The present study was designed to explore the mechanisms of peripheral nerve regeneration after different types of injury. Femoral nerves of rats were injured by crushing or freezing. At 2, 3, 6, and 12 weeks after injury, axons were retrogradely labeled using 1,1?-dioctadecyl-3,3,3?,3?-tetramethylindocarbocyanine perchlorate (Dil) and True Blue, and motor and sensory axons that had regenerated at the site of injury were counted. The number and percentage of Dil-labeled neurons in the anterior horn of the spinal cord increased over time. No significant differences were found in the number of labeled neurons between the freeze and crush injury groups at any time point. Our results confirmed that the accuracy of peripheral nerve regeneration increased with time, after both crush and freeze injury, and indicated that axonal regeneration accuracy was still satisfactory after freezing, despite the prolonged damage. PMID:26692867

  18. Fiber diameter distributions in the chinchilla's ampullary nerves

    NASA Technical Reports Server (NTRS)

    Hoffman, Larry F.; Honrubia, Vicente

    2002-01-01

    A morphometric study of the chinchilla's ampullary nerves was conducted to produce an unbiased accounting of the diameter distribution of their constituent fibers. Diameter analyses were determined from 1 microm plastic-embedded nerve sections taken at a plane immediately proximal to the sensory epithelium. We found these nerves to be composed of 2094+/-573 fibers, having diameters that ranged from 0.5 to 8 microm. The distributions of diameters were positively skewed, where approximately 75% of the fibers were found to have diameters less than 3.5 microm. An analysis of the spatial distribution of diameters within the nerve section revealed that the lateralmost areas of the nerve contained larger fractions of fibers within the smallest diameter quintiles, and the central area harbored greater proportions of the larger diameter quintiles. However, significant fractions of all quintiles were found in all areas. These data were integrated with available data of Fernandez et al. (1998) to produce diameter estimates of calyx, dimorphic, and bouton morphology subpopulations. In view of a general relationship between diameter, innervation locus, and an afferent's physiologic characteristics, these data provide the basis for developing a perspective for the in situ distribution of afferent response dynamics.

  19. Neural interfaces for regenerated nerve stimulation and recording.

    PubMed

    Dario, P; Garzella, P; Toro, M; Micera, S; Alavi, M; Meyer, U; Valderrama, E; Sebastiani, L; Ghelarducci, B; Mazzoni, C; Pastacaldi, P

    1998-12-01

    A class of implantable, regeneration-type neural interfaces (NI's) for mammalian peripheral nerve recording and stimulation were developed using different fabrication processes and integrating purposely designed components. A typical NI comprises three main components: 1) a microfabricated silicon die incorporating a microelectrode array on multiple through-holes, 2) a polymer guidance channel housing the die, and 3) a flexible flat cable connecting the die to an external electronic circuitry. The design and fabrication of the NI's were aimed at achieving long term, reliable implants by taking into careful account the biological, electrical, and mechanical requirements of the specific implant site. Different versions of the NI were fabricated and implanted between the severed ends of the sciatic nerve in a mammalian animal model (rabbit). Morphological and histological evidence showed that nerves regenerated through the NI's and electrophysiological results demonstrated the recovery of electrical functionality. Moreover, the NI's allowed stimulation of the regenerated nerve producing a visible leg/foot contraction. The NI's presented in this paper are being further improved in the authors' laboratories with the ultimate goal of allowing the control of nerve motor and sensory functions in future prosthetic devices. PMID:9865882

  20. Effects of methylmercury on the motor and sensory innervation of the rat extensor digitorum longus muscle

    SciTech Connect

    Yip, R.K.; Riley, D.A.

    1987-06-01

    The histochemical study examined the effects of chronic methylmercury (MeHg) intoxication on the motor and sensory innervation of extensor digitorum longus muscles. Light microscopic examination of silver-stained axons in the intramuscular nerve bundles of MeHg-treated rats showed Wallerian-like degeneration and a reduction in the number of nerve fibers. Disrupted axons were predominantly sensory because 22.2% of spindle afferents (I/sub a/) and 90.0% of Golgi tendon organ (I/sub b/) sensory fibers were completely degenerated whereas less than 1% of motor ending were totally destroyed. Partial disruption occurred in the cholinesterase and motor terminals of 13.7% of endplates. Their results demonstrated greater vulnerability of sensory nerves than of motor nerves to MeHg-induced degeneration. Thus, the abnormal reflexes, ataxia, and muscle weakness following MeHg poisoning appear related to reduction of proprioceptive feedback from muscles and tendons irradiation to the documented lesions in the central nervous system.

  1. chemical sensory cells distributed all over the body, arms and suckers.

    E-print Network

    Hochner, Binyamin

    Magazine R897 chemical sensory cells distributed all over the body, arms and suckers. Learning, watching what is happening around its tank. In this aspect octopuses differ completely from Aplysia, garden million nerve cells, more than four orders of magnitude greater than in other molluscs (garden snails

  2. Optic nerve hypoplasia in children.

    PubMed Central

    Zeki, S. M.; Dutton, G. N.

    1990-01-01

    Optic nerve hypoplasia (ONH) is characterised by a diminished number of optic nerve fibres in the optic nerve(s) and until recently was thought to be rare. It may be associated with a wide range of other congenital abnormalities. Its pathology, clinical features, and the conditions associated with it are reviewed. Neuroendocrine disorders should be actively sought in any infant or child with bilateral ONH. Early recognition of the disorder may in some cases be life saving. Images PMID:2191713

  3. Injured sensory neuron-derived CSF1 induces microglial proliferation and DAP12-dependent pain.

    PubMed

    Guan, Zhonghui; Kuhn, Julia A; Wang, Xidao; Colquitt, Bradley; Solorzano, Carlos; Vaman, Smitha; Guan, Andrew K; Evans-Reinsch, Zoe; Braz, Joao; Devor, Marshall; Abboud-Werner, Sherry L; Lanier, Lewis L; Lomvardas, Stavros; Basbaum, Allan I

    2016-01-01

    Although microglia have been implicated in nerve injury-induced neuropathic pain, the manner by which injured sensory neurons engage microglia remains unclear. We found that peripheral nerve injury induced de novo expression of colony-stimulating factor 1 (CSF1) in injured sensory neurons. CSF1 was transported to the spinal cord, where it targeted the microglial CSF1 receptor (CSF1R). Cre-mediated sensory neuron deletion of Csf1 completely prevented nerve injury-induced mechanical hypersensitivity and reduced microglial activation and proliferation. In contrast, intrathecal injection of CSF1 induced mechanical hypersensitivity and microglial proliferation. Nerve injury also upregulated CSF1 in motoneurons, where it was required for ventral horn microglial activation and proliferation. Downstream of CSF1R, we found that the microglial membrane adaptor protein DAP12 was required for both nerve injury- and intrathecal CSF1-induced upregulation of pain-related microglial genes and the ensuing pain, but not for microglial proliferation. Thus, both CSF1 and DAP12 are potential targets for the pharmacotherapy of neuropathic pain. PMID:26642091

  4. Agonist Binding and Desensitization of the ?-Opioid Receptor Is Modulated by Phosphorylation of the C-Terminal Tail Domain.

    PubMed

    Birdsong, William T; Arttamangkul, Seksiri; Bunzow, James R; Williams, John T

    2015-10-01

    Sustained activation of G protein-coupled receptors can lead to a rapid decline in signaling through acute receptor desensitization. In the case of the ?-opioid receptor (MOPr), this desensitization may play a role in the development of analgesic tolerance. It is understood that phosphorylation of MOPr promotes association with ?-arrestin proteins, which then facilitates desensitization and receptor internalization. Agonists that induce acute desensitization have been shown to induce a noncanonical high-affinity agonist binding state in MOPr, conferring a persistent memory of prior receptor activation. In the current study, live-cell confocal imaging was used to investigate the role of receptor phosphorylation in agonist binding to MOPr. A phosphorylation cluster in the C-terminal tail of MOPr was identified as a mediator of agonist-induced affinity changes in MOPr. This site is unique from the primary phosphorylation cluster responsible for ?-arrestin binding and internalization. Electrophysiologic measurements of receptor function suggest that both phosphorylation clusters may play a parallel role during acute receptor desensitization. Desensitization was unaffected by alanine mutation of either phosphorylation cluster, but was largely eliminated when both clusters were mutated. Overall, this work suggests that there are multiple effects of MOPr phosphorylation that appear to regulate MOPr function: one affecting ?-arrestin binding and a second affecting agonist binding. PMID:25934731

  5. Ischemic Nerve Block.

    ERIC Educational Resources Information Center

    Williams, Ian D.

    This experiment investigated the capability for movement and muscle spindle function at successive stages during the development of ischemic nerve block (INB) by pressure cuff. Two male subjects were observed under six randomly ordered conditions. The duration of index finger oscillation to exhaustion, paced at 1.2Hz., was observed on separate…

  6. Synaptic ultrastructure changes in trigeminocervical complex posttrigeminal nerve injury.

    PubMed

    Park, John; Trinh, Van Nancy; Sears-Kraxberger, Ilse; Li, Kang-Wu; Steward, Oswald; Luo, Z David

    2016-02-01

    Trigeminal nerves collecting sensory information from the orofacial area synapse on second-order neurons in the dorsal horn of subnucleus caudalis and cervical C1/C2 spinal cord (Vc/C2, or trigeminocervical complex), which is critical for sensory information processing. Injury to the trigeminal nerves may cause maladaptive changes in synaptic connectivity that plays an important role in chronic pain development. Here we examined whether injury to the infraorbital nerve, a branch of the trigeminal nerves, led to synaptic ultrastructural changes when the injured animals have developed neuropathic pain states. Transmission electron microscopy was used to examine synaptic profiles in Vc/C2 at 3 weeks postinjury, corresponding to the time of peak behavioral hypersensitivity following chronic constriction injury to the infraorbital nerve (CCI-ION). Using established criteria, synaptic profiles were classified as associated with excitatory (R-), inhibitory (F-), and primary afferent (C-) terminals. Each type was counted within the superficial dorsal horn of the Vc/C2 and the means from each rat were compared between sham and injured animals; synaptic contact length was also measured. The overall analysis indicates that rats with orofacial pain states had increased numbers and decreased mean synaptic length of R-profiles within the Vc/C2 superficial dorsal horn (lamina I) 3 weeks post-CCI-ION. Increases in the number of excitatory synapses in the superficial dorsal horn of Vc/C2 could lead to enhanced activation of nociceptive pathways, contributing to the development of orofacial pain states. J. Comp. Neurol. 524:309-322, 2016. © 2015 Wiley Periodicals, Inc. PMID:26132987

  7. Segmental thoracic lipomatosis of nerve with nerve territory overgrowth.

    PubMed

    Mahan, Mark A; Amrami, Kimberly K; Howe, B Matthew; Spinner, Robert J

    2014-05-01

    Lipomatosis of nerve (LN), or fibrolipomatous hamartoma, is a rare condition of fibrofatty enlargement of the peripheral nerves. It is associated with bony and soft tissue overgrowth in approximately one-third to two-thirds of cases. It most commonly affects the median nerve at the carpal tunnel or digital nerves in the hands and feet. The authors describe a patient with previously diagnosed hemihypertrophy of the trunk who had a history of large thoracic lipomas resected during infancy, a thoracic hump due to adipose proliferation within the thoracic paraspinal musculature, and scoliotic deformity. She had fatty infiltration in the thoracic spinal nerves on MRI, identical to findings pathognomonic of LN at better-known sites. Enlargement of the transverse processes at those levels and thickened ribs were also found. This case appears to be directly analogous to other instances of LN with overgrowth, except that this case involved axial nerves rather than the typical appendicular nerves. PMID:24506247

  8. Spatial sensitization and desensitization with small adapting fields: interactions of signals from different classes of cones.

    PubMed

    Stromeyer, C F

    1983-01-01

    Thresholds for brief, tiny flashes were measured on small adapting fields at 5 degrees retinal eccentricity. Rod influences was eliminated by bleaching. Green and red small adapting fields raised the threshold for a green test flash by stimulating both middle and long wave cones-thus spatial desensitization by small adapting fields is not con-specific. However, a small adapting field that strongly stimulated only short wave cones did not affect the visibility of a long wave flash. Spatial sensitization was also measured, using green or red annuli that surrounded a small red field and green test probe. Sensitization was not cone-specific. Possible mechanisms producing desensitization with small fields and annular sensitization are discussed. PMID:6613002

  9. [Aspirin desensitization: therapy options in patients with aspirin-exacerbated respiratory disease].

    PubMed

    Weber, R; Trautmann, A; Randerath, W; Heppt, W; Hosemann, W

    2012-04-01

    Aspirin desensitization has established itself as an additional therapy option in the treatment of aspirin- exacerbated respiratory disease, recurrent chronic rhinosinusitis and nasal polyps. Inpatient treatment is strongly recommended due to the risk of life-threatening side effects. In addition, the necessary requirements, indications and contraindications should be carefully considered from a medicolegal perspective. A maintenance dose of 300 (-500) mg ASS is currently recommended. Indications include persisting symptoms despite intensive medical care and/or recurrent nasal polyps, leading to recurrent sinus operations and/or the need to take systemic corticosteroids in order to control nasal symptoms or asthma. If ASS intake is interrupted for more than 48 h, aspirin desensitization should be resumed to prevent renewed intolerance reactions. PMID:22491884

  10. Eye movement desensitization and reprocessing (EMDR) in the treatment of war veterans.

    PubMed

    Silver, Steven M; Rogers, Susan; Russell, Mark

    2008-08-01

    Recent practice guidelines and meta-analyses have designated eye movement desensitization and reprocessing (EMDR) as a first-line treatment for trauma. Eye movement desensitization and reprocessing is an eight-phase therapeutic approach guided by an information-processing model that addresses the combat veteran's critical incidents, current triggers, and behaviors likely to prove useful in his or her future. Two case examples of combat veterans illustrate the ability of EMDR to achieve symptom reduction in a variety of clinical domains (e.g., anxiety, depression, anger, physical pain) simultaneously without requiring the patient to carry out homework assignments or discuss the details of the event. The treatment of phantom limb pain and other somatic presentations is also reviewed. The ability of EMDR to achieve positive effects without homework indicates that it can be effectively employed on consecutive days, making it especially useful during combat situations. PMID:18612994

  11. Desensitization of triggers and urge reprocessing for pathological gambling: a case series.

    PubMed

    Bae, Hwallip; Han, Changwoo; Kim, Daeho

    2015-03-01

    This case series introduces the desensitization of triggers and urge reprocessing (DeTUR), as a promising adjunctive therapy in addition to comprehensive treatment package for pathological gambling. This addiction protocol of eye movement desensitization and reprocessing was delivered to four male inpatients admitted to a 10-week inpatient program for pathological gambling. The therapist gave three 60-min weekly sessions of the DeTUR using bilateral stimulation (horizontal eye movements or alternative tactile stimuli) focusing on the hierarchy of triggering situations and the urge to initiate gambling behaviors. After treatment, self-reported gambling symptoms, depression, anxiety, and impulsiveness were all improved, and all the participants reported satisfaction with the therapy. They were followed up for 6 months and all maintained their abstinence from gambling and their symptomatic improvements. Given the efficiency (i.e., brevity and efficacy) of the treatment, a controlled study to confirm the effects of the DeTUR on pathological gambling would be justified. PMID:24293014

  12. Nanovesicle-Carbon Nanotube Hybrid Structures Mimicking Mammalian Pain Sensory System

    NASA Astrophysics Data System (ADS)

    Cho, Youngtac; Jin, Hye Jun; An, Jeong Mi; Park, Juhun; Moon, Seok Jun; Hong, Seunghun

    2015-03-01

    We developed a ``chemical-pain sensor'' based on a single-walled carbon nanotube-based field effect transistor (SWNT-FET) functionalized with rat pain sensory receptor, rat transient receptor potential vanilloid 1 (rTRPV1) mimicking a mammalian pain sensory system. The sensor can selectively detect chemical pain stimuli such as capsaicin and resiniferatoxin with a sensitivity of a 1 pM detection limit. Since this sensor allows one to quantitatively measure the concentration of chemical pain stimuli just like animal sensory systems, it can be used for various practical applications such as food screening. In addition, TRP families including rTRPV1 protein used for the sensor are now suggested as potential drug targets related to nerve and circulation disorders. Thus, the capability of measuring TRP responses using our sensor platform should open up other applications such as drug screening and basic research related with nerve and circulation systems.

  13. Desensitization of human adipose tissue to adrenaline stimulation studied by microdialysis.

    PubMed Central

    Stallknecht, B; Bülow, J; Frandsen, E; Galbo, H

    1997-01-01

    1. Desensitization of fat cell lipolysis to catecholamine exposure has been studied extensively in vitro but only to a small extent in human adipose tissue in vivo. 2. We measured interstitial glycerol concentrations by microdialysis in subcutaneous, abdominal adipose tissue in healthy humans during intravenous adrenaline infusion for three 35 min periods with 30 min breaks in between. Local blood flow, interstitial adrenaline and arterial glycerol concentrations were also measured. Adrenaline was infused to result in either a high, a low and a high arterial concentration (5.8, 3.1 and 5.6 nM, respectively) or a low, a high and a low concentration (2.5, 4.6 and 2.6 nM, respectively) in order to examine both desensitization and the dose dependency of adipose tissue lipolysis to adrenaline. 3. Adipose tissue lipolysis was calculated and was found to vary directly with arterial adrenaline concentration. However, lipolytic responses to adrenaline decreased markedly during repeated stimulation at a given concentration. Further, arterial glycerol and free fatty acid concentrations varied directly with arterial adrenaline concentrations and showed reduced responses upon repeated exposure. 4. The increase in adipose tissue blood flow in response to adrenaline was also reduced by prior adrenaline exposure, but no consistent desensitization could be demonstrated for whole-body energy expenditure, blood pressure and heart rate. 5. In the basal state, arterial plasma and interstitial adrenaline concentrations did not differ. During perturbations of arterial adrenaline concentrations, changes in interstitial concentrations were highly reproducible but smaller than changes in arterial concentrations. 6. In conclusion, in vivo adrenaline-mediated adipose tissue lipolysis and blood flow increments are desensitized by prior adrenaline exposure. PMID:9097951

  14. Influence of bleaching and desensitizing gel on bond strength of orthodontic brackets

    PubMed Central

    Britto, Fernanda Alves Rodrigues; Lucato, Adriana Simoni; Valdrighi, Heloisa Cristina; Vedovello, Sílvia Amélia Scudeler

    2015-01-01

    OBJECTIVE: The objective of this study was to assess, in vitro, the influence of bleaching gel and the use of desensitizing agent over bond strength of ceramic brackets bonded to bovine enamel. METHODS: One hundred bovine incisors were selected and randomly divided into five groups (n = 20): Group 1, control group (without bleaching); Group 2, bleached with 35% hydrogen peroxide; Group 3, bleached with 35% hydrogen peroxide (three applications, 15 minutes each) and desensitizing agent applied for 10 minutes; Group 4, bleached with 35% hydrogen peroxide for 40 minutes; Group 5, bleached with 35% hydrogen peroxide for 40 minutes with desensitizing agent applied for 10 minutes. Brackets were bonded 7 days after bleaching and submitted to shear bond strength test after 24 hours at a compression rate of 1 mm/minute. After fracture, the adhesive remnant index (ARI) was assessed under stereoscopic at 40 x magnification. Shear strength data (MPa) were submitted to one-way ANOVA and Tukey's test with significance level set at 5%. RESULTS: Group 5 (29.33 MPa) showed significantly higher bond strength than Group 1 (19.19 MPa), Group 2 (20.59 MPa) and Group 4 (23.25 MPa), but with no difference in comparison to Group 3. There was no significant difference among the other groups. The adhesive remnant index showed predominance of score 3, that is, all resin remained adhered to enamel for all groups. CONCLUSION: Bleaching with 35% hydrogen peroxide with calcium associated with desensitizing agent application produced higher bond strength values of brackets bonded to bovine enamel. PMID:25992987

  15. The Association between Serum Cytokines and Damage to Large and Small Nerve Fibers in Diabetic Peripheral Neuropathy

    PubMed Central

    Magrinelli, Francesca; Briani, Chiara; Romano, Marcello; Ruggero, Susanna; Toffanin, Elisabetta; Triolo, Giuseppa; Peter, George Chummar; Praitano, Marialuigia; Lauriola, Matteo Francesco; Zanette, Giampietro

    2015-01-01

    Diabetic peripheral neuropathy (DPN) is a frequent complication of type 2 diabetes mellitus (DM) and may involve small and large peripheral nerve fibers. Recent evidence suggests a role of cytokines in DPN. The paper is aimed at exploring whether the serum concentration of cytokines is associated with small and large nerve fiber function and with neuropathic pain (NP). We recruited a group of 32 type 2 DM patients who underwent serum cytokines (TNF-?, IL-2, IL-4, IL-6, and IL-10) dosage as well as electrodiagnostic and quantitative sensory testing (QST) assessment to explore damage to large and small nerve fibers. Raised serum levels of IL-6 and IL-10 correlated with markers of large nerve fiber sensory and motor axonal damage. Raised IL-10 serum level was associated with signs of motor nerve demyelination. No differences were found in pain characteristics and electrodiagnostic and QST markers of small nerve fiber function in relation to cytokines serum levels. IL-6 and IL-10 serum levels were associated with large nerve fiber damage but not to small fibers function or NP. IL-6 and IL-10 cytokines might play a role in the pathogenesis of nerve fiber damage or represent a compensatory or neuroprotective mechanism. PMID:25961054

  16. Successful desensitization protocol for hypersensitivity reaction probably caused by dabrafenib in a patient with metastatic melanoma.

    PubMed

    Bar-Sela, Gil; Abu-Amna, Mahmoud; Hadad, Salim; Haim, Nissim; Shahar, Eduardo

    2015-09-01

    Vemurafenib and dabrafenib are both orally bioavailable small molecule agents that block mitogen activated protein kinase signalling in patients with melanoma and BRAF(V600E) mutation. Generalized hypersensitivity reactions to vemurafenib or dabrafenib have not been described. Continuing vemurafenib or dabrafenib therapy despite hypersensitivity reaction is especially important in patients with melanoma and BRAF(V600E) mutation, in whom this mutation plays a critical role in tumour growth. Desensitization protocols to overcome hypersensitivity reactions by gradual reintroduction of small amounts of the offending drug up to full therapeutic doses are available for many anti-cancer agents, including vemurafenib but, to the best of our knowledge, have not been reported for dabrafenib. We describe a patient with metastatic melanoma who developed Type I hypersensitivity reaction to vemurafenib and to subsequent treatment with dabrafenib, and who was successfully treated by drug desensitization which allowed safe prolonged continuation of dabrafenib. The development of hypersensitivity reactions for both dabrafenib and vemurafinib in the current case could be because these drugs have a similar chemical structure and cause a cross-reactivity. However, hypersensitivity reaction to a non-medicinal ingredient shared by the two drugs is also possible. Oral desensitization appears to be an option for patients with hypersensitivity Type I to dabrafenib. This approach may permit clinicians to safely administer dabrafenib to patients who experience hypersensitivity reactions to this life-prolonging medication. PMID:26056325

  17. Desensitizing Agent Reduces Dentin Hypersensitivity During Ultrasonic Scaling: A Pilot Study

    PubMed Central

    Suda, Tomonari; Akiyama, Toshiharu; Takano, Takuya; Gokyu, Misa; Sudo, Takeaki; Khemwong, Thatawee; Izumi, Yuichi

    2015-01-01

    Background Dentin hypersensitivity can interfere with optimal periodontal care by dentists and patients. The pain associated with dentin hypersensitivity during ultrasonic scaling is intolerable for patient and interferes with the procedure, particularly during supportive periodontal therapy (SPT) for patients with gingival recession. Aim This study proposed to evaluate the desensitizing effect of the oxalic acid agent on pain caused by dentin hypersensitivity during ultrasonic scaling. Materials and Methods This study involved 12 patients who were incorporated in SPT program and complained of dentin hypersensitivity during ultrasonic scaling. We examined the availability of the oxalic acid agent to compare the degree of pain during ultrasonic scaling with or without the application of the dentin hypersensitivity agent. Evaluation of effects on dentin hypersensitivity was determined by a questionnaire and visual analog scale (VAS) pain scores after ultrasonic scaling. The statistical analysis was performed using the paired Student t-test and Spearman rank correlation coefficient. Results The desensitizing agent reduced the mean VAS pain score from 69.33 ± 16.02 at baseline to 26.08 ± 27.99 after application. The questionnaire revealed that >80% patients were satisfied and requested the application of the desensitizing agent for future ultrasonic scaling sessions. Conclusion This study shows that the application of the oxalic acid agent considerably reduces pain associated with dentin hypersensitivity experienced during ultrasonic scaling. This pain control treatment may improve patient participation and treatment efficiency. PMID:26501012

  18. Insulin induces alpha1B-adrenergic receptor phosphorylation and desensitization.

    PubMed

    García-Sáinz, J Adolfo; Romero-Avila, M Teresa; Molina-Muńoz, Tzindilú; Medina, Luz del Carmen

    2004-09-01

    The ability of insulin to induce alpha1B-adrenoceptor phosphorylation and desensitization was tested in two model systems: rat-1 cells that stably express alpha1B-adrenoceptors, through transfection, and endogenously express insulin receptors and DDT1 MF2 cells that endogenously express both receptors. Insulin induced concentration-dependent increases in the phosphorylation state of the adrenergic receptors in the two models with similar EC50 values (0.5-2 nM). The effect was rapid in the two systems but it was sustained in rat-1 cells and transient in DDT1 MF2 cells. In both cell lines, the insulin-mediated phosphorylation of alpha1B-adrenoceptors was blocked by wortmannin and LY 294002, and by staurosporine and bisindolylmaleimide I, indicating that the effect involved phosphoinositide 3-kinase and protein kinase C activities. The adrenoceptor phosphorylation induced by insulin was associated to desensitization as evidences by a diminished elevation of intracellular calcium in response to noradrenaline. Inhibitors of phosphoinositide 3-kinase and protein kinase C blocked the functional desensitization induced by insulin. PMID:15306161

  19. Environmental Awareness (Sensory Awareness).

    ERIC Educational Resources Information Center

    Carpenter, Marian

    Capitalizing on the resources available within a city block, this resource guide for the emotionally handicapped (K-6) describes methods and procedures for developing sensory awareness in the urban out-of-doors. Conceptual focus is on interdependency ("living things are interdependent"). Involvement in the environment (observing, thinking, doing)…

  20. Recording Sensory Words

    ERIC Educational Resources Information Center

    Ashbrook, Peggy

    2007-01-01

    From children's viewpoints, what they experience in the world is what the world is like--for everyone. "What do others experience with their senses when they are in the same situation?" is a question that young children can explore by collecting data as they use a "feely box," or take a "sensory walk." There are many ways to focus the children's…

  1. Structured Sensory Trauma Interventions

    ERIC Educational Resources Information Center

    Steele, William; Kuban, Caelan

    2010-01-01

    This article features the National Institute of Trauma and Loss in Children (TLC), a program that has demonstrated via field testing, exploratory research, time series studies, and evidence-based research studies that its Structured Sensory Intervention for Traumatized Children, Adolescents, and Parents (SITCAP[R]) produces statistically…

  2. INTRODUCTION Sensory antennae

    E-print Network

    Reichenbach, Tobias

    , on the scale of organs, the cornea and lens of the human eye constitute a sensory antenna that captures light antennae, for they provide a large surface over which to capture light and transfer the resultant, enhancing the animal's sensitivity, but also spectrally modifies the incoming sound (Middlebrooks and Green

  3. Our Sensory World.

    ERIC Educational Resources Information Center

    Liesman, C.; Barringer, M. D.

    The booklet explores the role of sensory experiences in the severely developmentally disabled child. Developmental theory is addressed, followed by specific activity suggestions (broken down into developmental levels) for developing tactile sense, auditory sense, gustatory (taste) sense, olfactory sense, visual sense, and kinesthetic sense.…

  4. Disorders of the lower cranial nerves

    PubMed Central

    Finsterer, Josef; Grisold, Wolfgang

    2015-01-01

    Lesions of the lower cranial nerves (LCN) are due to numerous causes, which need to be differentiated to optimize management and outcome. This review aims at summarizing and discussing diseases affecting LCN. Review of publications dealing with disorders of the LCN in humans. Affection of multiple LCN is much more frequent than the affection of a single LCN. LCN may be affected solely or together with more proximal cranial nerves, with central nervous system disease, or with nonneurological disorders. LCN lesions have to be suspected if there are typical symptoms or signs attributable to a LCN. Causes of LCN lesions can be classified as genetic, vascular, traumatic, iatrogenic, infectious, immunologic, metabolic, nutritional, degenerative, or neoplastic. Treatment of LCN lesions depends on the underlying cause. An effective treatment is available in the majority of the cases, but a prerequisite for complete recovery is the prompt and correct diagnosis. LCN lesions need to be considered in case of disturbed speech, swallowing, coughing, deglutition, sensory functions, taste, or autonomic functions, neuralgic pain, dysphagia, head, pharyngeal, or neck pain, cardiac or gastrointestinal compromise, or weakness of the trapezius, sternocleidomastoid, or the tongue muscles. To correctly assess manifestations of LCN lesions, precise knowledge of the anatomy and physiology of the area is required. PMID:26167022

  5. Understanding Sensory Integration. ERIC Digest.

    ERIC Educational Resources Information Center

    DiMatties, Marie E.; Sammons, Jennifer H.

    This brief paper summarizes what is known about sensory integration and sensory integration dysfunction (DSI). It outlines evaluation of DSI, treatment approaches, and implications for parents and teachers, including compensatory strategies for minimizing the impact of DSI on a child's life. Review of origins of sensory integration theory in the…

  6. Hunting for origins of migraine pain: cluster analysis of spontaneous and capsaicin-induced firing in meningeal trigeminal nerve fibers

    PubMed Central

    Zakharov, A.; Vitale, C.; Kilinc, E.; Koroleva, K.; Fayuk, D.; Shelukhina, I.; Naumenko, N.; Skorinkin, A.; Khazipov, R.; Giniatullin, R.

    2015-01-01

    Trigeminal nerves in meninges are implicated in generation of nociceptive firing underlying migraine pain. However, the neurochemical mechanisms of nociceptive firing in meningeal trigeminal nerves are little understood. In this study, using suction electrode recordings from peripheral branches of the trigeminal nerve in isolated rat meninges, we analyzed spontaneous and capsaicin-induced orthodromic spiking activity. In control, biphasic single spikes with variable amplitude and shapes were observed. Application of the transient receptor potential vanilloid 1 (TRPV1) agonist capsaicin to meninges dramatically increased firing whereas the amplitudes and shapes of spikes remained essentially unchanged. This effect was antagonized by the specific TRPV1 antagonist capsazepine. Using the clustering approach, several groups of uniform spikes (clusters) were identified. The clustering approach combined with capsaicin application allowed us to detect and to distinguish “responder” (65%) from “non-responder” clusters (35%). Notably, responders fired spikes at frequencies exceeding 10 Hz, high enough to provide postsynaptic temporal summation of excitation at brainstem and spinal cord level. Almost all spikes were suppressed by tetrodotoxin (TTX) suggesting an involvement of the TTX-sensitive sodium channels in nociceptive signaling at the peripheral branches of trigeminal neurons. Our analysis also identified transient (desensitizing) and long-lasting (slowly desensitizing) responses to the continuous application of capsaicin. Thus, the persistent activation of nociceptors in capsaicin-sensitive nerve fibers shown here may be involved in trigeminal pain signaling and plasticity along with the release of migraine-related neuropeptides from TRPV1 positive neurons. Furthermore, cluster analysis could be widely used to characterize the temporal and neurochemical profiles of other pain transducers likely implicated in migraine. PMID:26283923

  7. Modulation of sensory irritation responsiveness by adenosine and malodorants.

    PubMed

    Willis, Daniel N; Morris, John B

    2013-01-01

    Respiratory tract reflex responses are an important defense mechanism against noxious airborne materials. This study was aimed at defining the effects of adenosine on sensory irritation responsiveness and its role in odorant-irritant interactions. These experiments were aimed at testing the hypothesis that adenosine, through the A2 receptor, enhances trigeminal nerve responses to multiple irritants and that odorants enhance responsiveness to irritants through A2 pathways in the female C57Bl/6 mouse. The adenosine precursor, AMP, immediately and markedly increased the sensory irritation response to capsaicin, cyclohexanone, and styrene, irritants that activate chemosensory nerves through differing receptor pathways. The neuromodulatory effect was blocked by the general adenosine receptor antagonist theophylline and by the A2 receptor-specific antagonist DMPX. Multiple odorants were examined, including R-carvone (spearmint), linalool (lavender), trimethylamine (rotting fish), mercaptoethanol, and ethyl sulfide (stench and rotten eggs). Of these, only mercaptoethanol and ethyl sulfide exhibited neuromodulatory effects, enhancing the sensory irritation response to styrene or cyclohexanone. This effect was blocked by theophylline and DMPX indicating the importance of adenosine A2 receptor pathways in this effect. These results highlight that trigeminal chemosensory responsiveness is not static, but can be quickly modulated by adenosine and select odors resulting in hyperresponsive states. PMID:23162088

  8. Anatomical Study of the Ulnar Nerve Variations at High Humeral Level and Their Possible Clinical and Diagnostic Implications

    PubMed Central

    Guru, Anitha; Kumar, Naveen; Ravindra Shanthakumar, Swamy; Patil, Jyothsna; Nayak Badagabettu, Satheesha; Aithal Padur, Ashwini; Nelluri, Venu Madhav

    2015-01-01

    Background. Descriptive evaluation of nerve variations plays a pivotal role in the usefulness of clinical or surgical practice, as an anatomical variation often sets a risk of nerve palsy syndrome. Ulnar nerve (UN) is one amongst the major nerves involved in neuropathy. In the present anatomical study, variations related to ulnar nerve have been identified and its potential clinical implications discussed. Materials and Method. We examined 50 upper limb dissected specimens for possible ulnar nerve variations. Careful observation for any aberrant formation and/or communication in relation to UN has been carried out. Results. Four out of 50 limbs (8%) presented with variations related to ulnar nerve. Amongst them, in two cases abnormal communication with neighboring nerve was identified and variation in the formation of UN was noted in remaining two limbs. Conclusion. An unusual relation of UN with its neighboring nerves, thus muscles, and its aberrant formation might jeopardize the normal sensori-motor behavior. Knowledge about anatomical variations of the UN is therefore important for the clinicians in understanding the severity of ulnar nerve neuropathy related complications. PMID:26246909

  9. Topohistology of sympathetic and parasympathetic nerve fibers in branches of the pelvic plexus: an immunohistochemical study using donated elderly cadavers

    PubMed Central

    Hieda, Keisuke; Sasaki, Hiromasa; Murakami, Gen; Abe, Shinichi; Matsubara, Akio; Miyake, Hideaki; Fujisawa, Masato

    2014-01-01

    Although the pelvic autonomic plexus may be considered a mixture of sympathetic and parasympathetic nerves, little information on its composite fibers is available. Using 10 donated elderly cadavers, we investigated in detail the topohistology of nerve fibers in the posterior part of the periprostatic region in males and the infero-anterior part of the paracolpium in females. Neuronal nitric oxide synthase (nNOS) and vasoactive intestinal polypeptide (VIP) were used as parasympathetic nerve markers, and tyrosine hydroxylase (TH) was used as a marker of sympathetic nerves. In the region examined, nNOS-positive nerves (containing nNOS-positive fibers) were consistently predominant numerically. All fibers positive for these markers appeared to be thin, unmyelinated fibers. Accordingly, the pelvic plexus branches were classified into 5 types: triple-positive mixed nerves (nNOS+, VIP+, TH+, thick myelinated fibers + or -); double-positive mixed nerves (nNOS+, VIP-, TH+, thick myelinated fibers + or -); nerves in arterial walls (nNOS-, VIP+, TH+, thick myelinated fibers-); non-parasympathetic nerves (nNOS-, VIP-, TH+, thick myelinated fibers + or -); (although rare) pure sensory nerve candidates (nNOS-, VIP-, TH-, thick myelinated fibers+). Triple-positive nerves were 5-6 times more numerous in the paracolpium than in the periprostatic region. Usually, the parasympathetic nerve fibers did not occupy a specific site in a nerve, and were intermingled with sympathetic fibers. This morphology might be the result of an "incidentally" adopted nerve fiber route, rather than a target-specific pathway. PMID:24693483

  10. Spinal nerve segmentation in the chick embryo: analysis of distinct axon-repulsive systems.

    PubMed

    Vermeren, M M; Cook, G M; Johnson, A R; Keynes, R J; Tannahill, D

    2000-09-01

    In higher vertebrates, the segmental organization of peripheral spinal nerves is established by a repulsive mechanism whereby sensory and motor axons are excluded from the posterior half-somite. A number of candidate axon repellents have been suggested to mediate this barrier to axon growth, including Sema3A, Ephrin-B, and peanut agglutinin (PNA)-binding proteins. We have tested the candidacy of these factors in vitro by examining their contribution to the growth cone collapse-inducing activity of somite-derived protein extracts on sensory, motor, and retinal axons. We find that Sema3A is unlikely to play a role in the segmentation of sensory or motor axons and that Ephrin-B may contribute to motor but not sensory axon segmentation. We also provide evidence that the only candidate molecule(s) that induces the growth cone collapse of both sensory and motor axons binds to PNA and is not Sema3A or Ephrin-B. By grafting primary sensory, motor, and quail retinal neurons into the chick trunk in vivo, we provide further evidence that the posterior half-somite represents a universal barrier to growing axons. Taken together, these results suggest that the mechanisms of peripheral nerve segmentation should be considered in terms of repellent molecules in addition to the identified molecules. PMID:10964478

  11. A comparative evaluation of the effect of dentin desensitizers on the retention of complete cast metal crowns

    PubMed Central

    Chandavarkar, Saili M.; Ram, Sabita M.

    2015-01-01

    Context: Desensitizers are used to reduce dentin hypersensitivity. They affect the surface texture of prepared dentin and may alter the retention of fixed restorations. Aims: The aim was to evaluate the effect of dentin desensitizers on the retention of complete cast metal crowns luted with glass ionomer cement. Subjects and Methods: Fifty freshly extracted human premolars were subjected to standardized tooth preparation (20° total convergence, 4 mm axial height) with a computer numerically controlled machine. Individual cast metal crowns were fabricated from a base metal alloy. Dentin desensitizers included none (control), a glutaraldehyde (GLU) based primer (Gluma desensitizer), casein phosphopeptide (CPP)-amorphous calcium phosphate (ACP) (GC Mousse), erbium, chromium: YSGG laser (Waterlase MD Turbo, Biolase) and Pro-Argin (Colgate Sensitive Pro-Relief desensitizing polishing paste). After desensitization, crowns were luted with glass ionomer cement and kept for 48 h at 37°C in 100% relative humidity. The samples were tested using a universal testing machine by applying a load at a crosshead speed of 0.5 mm/min. Statistical Analysis Used: Statistical analysis included One-way ANOVA, followed by the Scheffe post-hoc test with P < 0.05. Results: All dentin desensitizers showed significantly different values: Pro-Argin (4.10 Megapascals [Mpa]) < CPP-ACP (4.01 mpa) < GLU based primer (3.87 Mpa) < Virgin dentin (3.65 Mpa) < LASER (3.37 Mpa). Conclusions: On comparing the effect of prepared virgin dentin, GLU based primer, CPP-ACP, LASER and Pro-Argin on the retention of complete cast metal crowns luted with glass ionomer cement on prepared teeth, it can be concluded that Pro-Argin and CPP-ACP showed the best retention in this in vitro study. PMID:25821374

  12. Ultrasound of Peripheral Nerves

    PubMed Central

    Suk, Jung Im; Walker, Francis O.; Cartwright, Michael S.

    2013-01-01

    Over the last decade, neuromuscular ultrasound has emerged as a useful tool for the diagnosis of peripheral nerve disorders. This article reviews sonographic findings of normal nerves including key quantitative ultrasound measurements that are helpful in the evaluation of focal and possibly generalized peripheral neuropathies. It also discusses several recent papers outlining the evidence base for the use of this technology, as well as new findings in compressive, traumatic, and generalized neuropathies. Ultrasound is well suited for use in electrodiagnostic laboratories where physicians, experienced in both the clinical evaluation of patients and the application of hands-on technology, can integrate findings from the patient’s history, physical examination, electrophysiological studies, and imaging for diagnosis and management. PMID:23314937

  13. Changes in the Distribution of Periodontal Nerve Fibers during Dentition Transition in the Cat

    PubMed Central

    Miki, Koji; Honma, Shiho; Ebara, Satomi; Kumamoto, Kenzo; Murakami, Shinya; Wakisaka, Satoshi

    2015-01-01

    The periodontal ligament has a rich sensory nerve supply which originates from the trigeminal ganglion and trigeminal mesencephalic nucleus. Although various types of mechanoreceptors have been reported in the periodontal ligament, the Ruffini ending is an essential one. It is unknown whether the distribution of periodontal nerve fibers in deciduous teeth is identical to that in permanent teeth or not. Moreover, morphological changes in the distribution of periodontal nerve fibers during resorption of deciduous teeth and eruption of successional permanent teeth in diphyodont animals have not been reported in detail. Therefore, in this study, we examined changes in the distribution of periodontal nerve fibers in the cat during changes in dentition (i.e., deciduous, mixed and permanent dentition) by immunohistochemistry of protein gene product 9.5. During deciduous dentition, periodontal nerve fibers were concentrated at the apical portion, and sparsely distributed in the periodontal ligament of deciduous molars. During mixed dentition, the periodontal nerve fibers of deciduous molars showed degenerative profiles during resorption. In permanent dentition, the periodontal nerve fibers of permanent premolars, the successors of deciduous molars, increased in number. Similar to permanent premolars, the periodontal nerve fibers of permanent molars, having no predecessors, increased in number, and were densely present in the apical portion. The present results indicate that the distribution of periodontal nerve fibers in deciduous dentition is almost identical to that in permanent dentition although the number of periodontal nerve fibers in deciduous dentition was low. The sparse distribution of periodontal nerve fibers in deciduous dentition agrees with clinical evidence that children are less sensitive to tooth stimulation than adults. PMID:26083023

  14. Sensory Organs Types of Sensory Stimuli Insects detect 4 types of sensory

    E-print Network

    Brown, Christopher A.

    Photoreceptors These detect photons of light Photon strikes a pigment cell, causing a chemical or mechanical1 Sensory Organs Types of Sensory Stimuli Insects detect 4 types of sensory stimuli: Mechanical Heat/temperature Chemical Visual Mechanoreceptors These detect pressure changes resulting from: Air

  15. [Suprascapular nerve entrapment].

    PubMed

    Fansa, H; Schneider, W

    2003-03-01

    Isolated compression of the suprascapular nerve is a rare entity, that is seldom considered in differential diagnosis of shoulder pain. Usually atrophy of supraspinatus and infraspinatus muscles is present, resulting in weakened abduction and external rotation of the shoulder. Mostly the patients do not note the paresis, but complain about a dull and burning pain over the dorsal shoulder region. In a proximal lesion (at level of the superior transverse scapular ligament) electromyography reveals changes in both muscles, while in a distal lesion (spinoglenoidal notch) only the infraspinatus shows a pathology. From 1996 to 2001 we diagnosed an isolated suprascapular entrapment in nine patients. Seven patients were operated: The ligament was removed and the nerve was neurolysed. The average age was 36 years. All patients showed pathological findings in electrophysiological and clinical examination. Five patients had an atrophy of both scapula muscles, two showed only infraspinatus muscle atrophy (one with a ganglion in the distal course of the nerve). Six patients were followed up. All showed an improvement. Pain disappeared and all patients were able to return to work and sport activities. Electrophysiological examination one year after operation revealed normal nerve conduction velocity. The number of motor units, however, showed a reduction by half compared to the healthy side. Lesions without history of trauma are usually caused by repetitive motion or posture. Weight lifting, volley ball and tennis promote the entrapment. Rarely a lesion (either idiopathic or due to external compression) is described for patients who underwent surgery. Patients with a ganglion or a defined cause of compression should be operated, patients who present without a distinct reason for compression should firstly be treated conservatively. Physiotherapy, antiphlogistic medication and avoiding of the pain triggering motion can improve the symptoms. However, if muscle atrophy is evident, an operation is indicated from our experience. PMID:12874724

  16. Cranial Nerve II: Vision.

    PubMed

    Gillig, Paulette Marie; Sanders, Richard D

    2009-09-01

    This article contains a brief review of the anatomy of the visual system, a survey of diseases of the retina, optic nerve and lesions of the optic chiasm, and other visual field defects of special interest to the psychiatrist. It also includes a presentation of the corticothalamic mechanisms, differential diagnosis, and various manifestations of visual illusions, and simple and complex visual hallucinations, as well as the differential diagnoses of these various visual phenomena. PMID:19855858

  17. Superficial radial nerve–lateral antebrachial cutaneous nerve anatomic variation

    PubMed Central

    Davidovich, Eduardo R; Nascimento, Osvaldo J M

    2014-01-01

    Introduction This study focuses on an anatomic variation in which the lateral antebrachial cutaneous nerve (LACN) innervates the radial border of the dorsum of the hand and thumb in addition to, or replacing, the superficial radial nerve (RSN). Here, we propose a technique of nerve conduction that identifies this variation. Methods We studied nerve conduction in 200 upper limbs of two series of 50 volunteers. We sought evidence of the aforementioned variation on the dorsum of the hand and in the thumb. Results We found eight occurrences of this variation on the dorsum of the hand and 11 variants on the thumb within the two respective series of 100 upper limbs studied. Discussion The RSN–LACN anatomic variation can be studied using nerve conduction. The knowledge of this variation is particularly important for the evaluation of proximal radial nerve injury. PMID:24653956

  18. Optic nerve hypoplasia

    PubMed Central

    Kaur, Savleen; Jain, Sparshi; Sodhi, Harsimrat B. S.; Rastogi, Anju; Kamlesh

    2013-01-01

    Optic nerve hypoplasia (ONH) is a congenital anomaly of the optic disc that might result in moderate to severe vision loss in children. With a vast number of cases now being reported, the rarity of ONH is obviously now refuted. The major aspects of ophthalmic evaluation of an infant with possible ONH are visual assessment, fundus examination, and visual electrophysiology. Characteristically, the disc is small, there is a peripapillary double-ring sign, vascular tortuosity, and thinning of the nerve fiber layer. A patient with ONH should be assessed for presence of neurologic, radiologic, and endocrine associations. There may be maternal associations like premature births, fetal alcohol syndrome, maternal diabetes. Systemic associations in the child include endocrine abnormalities, developmental delay, cerebral palsy, and seizures. Besides the hypoplastic optic nerve and chiasm, neuroimaging shows abnormalities in ventricles or white- or gray-matter development, septo-optic dysplasia, hydrocephalus, and corpus callosum abnormalities. There is a greater incidence of clinical neurologic abnormalities in patients with bilateral ONH (65%) than patients with unilateral ONH. We present a review on the available literature on the same to urge caution in our clinical practice when dealing with patients with ONH. Fundus photography, ocular coherence tomography, visual field testing, color vision evaluation, neuroimaging, endocrinology consultation with or without genetic testing are helpful in the diagnosis and management of ONH. (Method of search: MEDLINE, PUBMED). PMID:24082663

  19. Sensory Attenuation Assessed by Sensory Evoked Potentials in Functional Movement Disorders

    PubMed Central

    Macerollo, Antonella; Chen, Jui-Cheng; Pareés, Isabel; Kassavetis, Panagiotis; Kilner, James Morvan; Edwards, Mark John

    2015-01-01

    Background Functional (psychogenic) movement disorders (FMD) have features associated with voluntary movement (e.g. distractibility) but patients report movements to be out of their control. One explanation for this phenomenon is that sense of agency for movement is impaired. The phenomenon of reduction in the intensity of sensory experience when movement is self-generated and a reduction in sensory evoked potentials (SEPs) amplitude at the onset of self-paced movement (sensory attenuation) have been linked to sense of agency for movement. Methods We compared amplitude of SEPs from median nerve stimulation at rest and at the onset of a self-paced movement of the thumb in 17 patients with FMD and 17 healthy controls. Results Patients showed lack of attenuation of SEPs at the onset of movement compared to reduction in amplitude of SEPs in controls. FMD patients had significantly different ratios of movement onset to rest SEPs than did healthy controls at each electrode: 0.79 in healthy controls and 1.35 in patients at F3 (t = -4.22, p<0.001), 0.78 in healthy controls and 1.12 at patients C3 (t = -3.15, p = 0.004) and 0.77 in healthy controls and 1.05 at patients P3 (t = -2.88, p = 0.007). Conclusions Patients with FMD have reduced sensory attenuation as measured by SEPs at onset of self-paced movement. This finding can be plausibly linked to impairment of sense of agency for movement in these patients. PMID:26091500

  20. The effects of 5-HT on sensory, central and motor neurons driving the abdominal superficial flexor muscles in the crayfish.

    PubMed

    Strawn, J R; Neckameyer, W S; Cooper, R L

    2000-12-01

    Serotonin (5-HT) induces a variety of physiological and behavioral effects in crustaceans. However, the mechanisms employed by 5-HT to effect behavioral changes are not fully understood. Among the mechanisms by which these changes might occur are alterations in synaptic drive and efficacy of sensory, interneurons and motor neurons, as well as direct effects on muscles. We investigated these aspects with the use of a defined sensory-motor system, which is entirely contained within a single abdominal segment and consists of a 'cuticular sensory neurons segmental ganglia abdominal superficial flexor motor neurons-muscles' circuit. Our studies address the role of 5-HT in altering (1) the activity of motor neurons induced by sensory stimulation; (2) the inherent excitability of superficial flexor motor neurons; (3) transmitter release properties of the motor nerve terminal and (4) input resistance of the muscle. Using en passant recordings from the motor nerve, with and without sensory stimulation, and intracellular recordings from the muscle, we show that 5-HT enhances sensory drive and output from the ventral nerve cord resulting in an increase in the firing frequency of the motor neurons. Also, 5-HT increases transmitter release at the neuromuscular junction, and alters input resistance of the muscle fibers. PMID:11281271

  1. Stability and selectivity of a chronic, multi-contact cuff electrode for sensory stimulation in human amputees

    NASA Astrophysics Data System (ADS)

    Tan, Daniel W.; Schiefer, Matthew A.; Keith, Michael W.; Anderson, J. Robert; Tyler, Dustin J.

    2015-04-01

    Objective. Stability and selectivity are important when restoring long-term, functional sensory feedback in individuals with limb-loss. Our objective is to demonstrate a chronic, clinical neural stimulation system for providing selective sensory response in two upper-limb amputees. Approach. Multi-contact cuff electrodes were implanted in the median, ulnar, and radial nerves of the upper-limb. Main results. Nerve stimulation produced a selective sensory response on 19 of 20 contacts and 16 of 16 contacts in subjects 1 and 2, respectively. Stimulation elicited multiple, distinct percept areas on the phantom and residual limb. Consistent threshold, impedance, and percept areas have demonstrated that the neural interface is stable for the duration of this on-going, chronic study. Significance. We have achieved selective nerve response from multi-contact cuff electrodes by demonstrating characteristic percept areas and thresholds for each contact. Selective sensory response remains consistent in two upper-limb amputees for 1 and 2 years, the longest multi-contact sensory feedback system to date. Our approach demonstrates selectivity and stability can be achieved through an extraneural interface, which can provide sensory feedback to amputees.

  2. Intact radial and median nerve after open third degree distal fracture of the humerus.

    PubMed

    Has, Borislav; Kvolik, Slavica; Kristek, Jozo; Habek, Dubravko

    2006-06-01

    A 54 year old man sustained a third degree open fracture at the distal part of the right humerus with massive soft tissue defect involving most of the upper arm. The radial and median nerves were completely bared and exposed by 6 cm for radial and 3 cm for median nerve. The nerves were in continuity, but there was complete rupture of surrounding muscles: biceps, triceps and brachialis. The fracture was stabilized by external fixation method--reinforced by wires. Preoperative and postoperative sensorimotor status of the right hand was good. One year later sensory and motoric status of right hand showed no deficiencies, but flexion and extension in elbow were limited to 100 and 180 degrees respectively. Pronosupination was restricted. This case report is consistent with results of biomechanical studies in vitro confirming high tolerance of radial and median nerve to stretching injury. PMID:16848166

  3. Quantitative sensory testing.

    PubMed

    Soomekh, David

    2006-07-01

    The diagnosis and treatment of peripheral neuropathy from any cause has come to the forefront of the research community in the past few years. Both past and new diagnostic and treatment options have been and are being studied to better understand and properly treat this debilitating and sometimes devastating disease. One such advancement is the clinical use of quantitative sensory testing. To identify etiology of the neuropathy early, the testing instrument would need to identify changes throughout the course of the disease, have a normative database, and show a clear distinction between the absence or presence of disease. The pressure specified sensory device (PSSD) was developed in 1992 to painlessly investigate the cutaneous pressure thresholds quantitatively and accurately. PMID:16958387

  4. Instabilities in sensory processes

    NASA Astrophysics Data System (ADS)

    Balakrishnan, J.

    2014-07-01

    In any organism there are different kinds of sensory receptors for detecting the various, distinct stimuli through which its external environment may impinge upon it. These receptors convey these stimuli in different ways to an organism's information processing region enabling it to distinctly perceive the varied sensations and to respond to them. The behavior of cells and their response to stimuli may be captured through simple mathematical models employing regulatory feedback mechanisms. We argue that the sensory processes such as olfaction function optimally by operating in the close proximity of dynamical instabilities. In the case of coupled neurons, we point out that random disturbances and fluctuations can move their operating point close to certain dynamical instabilities triggering synchronous activity.

  5. CRYPTOGENIC SENSORY POLYNEUROPATHY

    PubMed Central

    Pasnoor, Mamatha; Dimachkie, Mazen M.; Barohn, Richard J.

    2014-01-01

    Chronic sensory or sensorimotor polyneuropathy is a common cause for referral to neurologists. Despite extensive diagnostic testing, up to one-third of these patients remain without a known cause. They are referred to as having cryptogenic sensory peripheral neuropathy (CSPN). The age of onset is variable but usually in the sixth to seventh decade of life, affecting men and women equally. CSPN symptoms progress slowly, most patients present with distal leg paresthesias or pain that progressed over years to involve the hands. On examination, there may be additional mild toe flexion and extension weakness. Electrophysiologic testing and histology reveals axonal neuropathy. Prognosis is usually favorable as most patients maintain independent ambulation. Besides patient education and reassurance, management is focused on pharmacotherapy of neuropathic pain (see Treatment of Painful Peripheral Neuropathy chapter) and physical therapy for balance training and occasionally assistive devices. PMID:23642719

  6. The central projections of the laryngeal nerves in the rat

    PubMed Central

    Pascual-Font, Arán; Hernández-Morato, Ignacio; McHanwell, Stephen; Vázquez, Teresa; Maranillo, Eva; Sańudo, Jose; Valderrama-Canales, Francisco J

    2011-01-01

    The larynx serves respiratory, protective, and phonatory functions. The motor and sensory innervation to the larynx controlling these functions is provided by the superior laryngeal nerve (SLN) and the recurrent laryngeal nerve (RLN). Classical studies state that the SLN innervates the cricothyroid muscle and provides sensory innervation to the supraglottic cavity, whereas the RLN supplies motor innervation to the remaining intrinsic laryngeal muscles and sensory innervation to the infraglottic cavity, but recent data suggest a more complex anatomical and functional organisation. The current neuroanatomical tracing study was undertaken to provide a comprehensive description of the central brainstem connections of the axons within the SLN and the RLN, including those neurons that innervate the larynx. The study has been carried out in 41 adult male Sprague–Dawley rats. The central projections of the laryngeal nerves were labelled following application of biotinylated dextran amines onto the SLN, the RLN or both. The most remarkable result of the study is that in the rat the RLN does not contain any afferent axons from the larynx, in contrast to the pattern observed in many other species including man. The RLN supplied only special visceromotor innervation to the intrinsic muscles of the larynx from motoneurons in the nucleus ambiguus (Amb). All the afferent axons innervating the larynx are contained within the SLN, and reach the nucleus of the solitary tract. The SLN also contained secretomotor efferents originating from motoneurons in the dorsal motor nucleus of the vagus, and special visceral efferent fibres from the Amb. In conclusion, the present study shows that in the rat the innervation of the larynx differs in significant ways from that described in other species. PMID:21599662

  7. The central projections of the laryngeal nerves in the rat.

    PubMed

    Pascual-Font, Arán; Hernández-Morato, Ignacio; McHanwell, Stephen; Vázquez, Teresa; Maranillo, Eva; Sańudo, Jose; Valderrama-Canales, Francisco J

    2011-08-01

    The larynx serves respiratory, protective, and phonatory functions. The motor and sensory innervation to the larynx controlling these functions is provided by the superior laryngeal nerve (SLN) and the recurrent laryngeal nerve (RLN). Classical studies state that the SLN innervates the cricothyroid muscle and provides sensory innervation to the supraglottic cavity, whereas the RLN supplies motor innervation to the remaining intrinsic laryngeal muscles and sensory innervation to the infraglottic cavity, but recent data suggest a more complex anatomical and functional organisation. The current neuroanatomical tracing study was undertaken to provide a comprehensive description of the central brainstem connections of the axons within the SLN and the RLN, including those neurons that innervate the larynx. The study has been carried out in 41 adult male Sprague-Dawley rats. The central projections of the laryngeal nerves were labelled following application of biotinylated dextran amines onto the SLN, the RLN or both. The most remarkable result of the study is that in the rat the RLN does not contain any afferent axons from the larynx, in contrast to the pattern observed in many other species including man. The RLN supplied only special visceromotor innervation to the intrinsic muscles of the larynx from motoneurons in the nucleus ambiguus (Amb). All the afferent axons innervating the larynx are contained within the SLN, and reach the nucleus of the solitary tract. The SLN also contained secretomotor efferents originating from motoneurons in the dorsal motor nucleus of the vagus, and special visceral efferent fibres from the Amb. In conclusion, the present study shows that in the rat the innervation of the larynx differs in significant ways from that described in other species. PMID:21599662

  8. Neuromuscular Ultrasound of Cranial Nerves

    PubMed Central

    Tawfik, Eman A.; Cartwright, Michael S.

    2015-01-01

    Ultrasound of cranial nerves is a novel subdomain of neuromuscular ultrasound (NMUS) which may provide additional value in the assessment of cranial nerves in different neuromuscular disorders. Whilst NMUS of peripheral nerves has been studied, NMUS of cranial nerves is considered in its initial stage of research, thus, there is a need to summarize the research results achieved to date. Detailed scanning protocols, which assist in mastery of the techniques, are briefly mentioned in the few reference textbooks available in the field. This review article focuses on ultrasound scanning techniques of the 4 accessible cranial nerves: optic, facial, vagus and spinal accessory nerves. The relevant literatures and potential future applications are discussed. PMID:25851889

  9. Use of Peripheral Nerve Blocks with Sedation for Total Knee Arthroplasty in a Patient with Contraindication for General Anesthesia

    PubMed Central

    Kamenetsky, Eric; Nader, Antoun; Kendall, Mark C.

    2015-01-01

    Although peripheral nerve blocks are commonly used to provide postoperative analgesia after total knee arthroplasty (TKA) and other lower extremity procedures, these blocks are rarely used for intraoperative anesthesia. Most TKAs are performed under general anesthesia (GA) or neuraxial anesthesia (NA). The knee has a complex sensory innervation that makes surgical anesthesia difficult with peripheral nerve blocks alone. Rarely are both GA and NA relatively contraindicated and alternatives are considered. We present a patient who underwent TKA performed under peripheral nerve block and sedation alone. PMID:26587290

  10. Dysfunctional penile cholinergic nerves in diabetic impotent men

    SciTech Connect

    Blanco, R.; Saenz de Tejada, I.; Goldstein, I.; Krane, R.J.; Wotiz, H.H.; Cohen, R.A. )

    1990-08-01

    Impotence in the diabetic man may be secondary to a neuropathic condition of the autonomic penile nerves. The relationship between autonomic neuropathy and impotence in diabetes was studied in human corporeal tissue obtained during implantation of a penile prosthesis in 19 impotent diabetic and 15 nondiabetic patients. The functional status of penile cholinergic nerves was assessed by determining their ability to accumulate tritiated choline (34), and synthesize (34) and release (19) tritiated-acetylcholine after incubation of corporeal tissue with tritiated-choline (34). Tritiated-choline accumulation, and tritiated-acetylcholine synthesis and release were significantly reduced in the corporeal tissue from diabetic patients compared to that from nondiabetic patients (p less than 0.05). The impairment in acetylcholine synthesis worsened with the duration of diabetes (p less than 0.025). No differences in the parameters measured were found between insulin-dependent (11) and noninsulin-dependent (8) diabetic patients. The ability of the cholinergic nerves to synthesize acetylcholine could not be predicted clinically with sensory vibration perception threshold testing. It is concluded that there is a functional penile neuropathic condition of the cholinergic nerves in the corpus cavernosum of diabetic impotent patients that may be responsible for the erectile dysfunction.

  11. EFFECT OF FLUORIDE-CONTAINING DESENSITIZING AGENTS ON THE BOND STRENGTH OF RESIN-BASED CEMENTS TO DENTIN

    PubMed Central

    Saraç, Duygu; Külünk, Safak; Saraç, Y. Sinasi; Karakas, Özlem

    2009-01-01

    Objective: The objective of this study was to evaluate the effect of desensitizing agents containing different amounts of fluoride on the shear bond strength of a dual polymerized resin cement and a resin-modified glass ionomer cement (RMGIC) to dentin. Material and Methods: One hundred human molars were mounted in acrylic resin blocks and prepared until the dentin surface was exposed. The specimens were treated with one of four desensitizing agents: Bifluorid 12, Fluoridin, Thermoline and PrepEze. The remaining 20 specimens served as untreated controls. All groups were further divided into 2 subgroups in which a dual polymerized resin cement (Bifix QM) or a resin-modified glass ionomer cement (AVANTO) was used. The shear bond strength (MPa) was measured using a universal testing machine at a 0.5 mm/min crosshead speed. The data were analyzed statistically with a 2-way ANOVA, Tukey HSD test and regression analysis (?=0.05). The effect of the desensitizing agents on the dentin surface was examined by scanning electron microscopy. Results: The fluoride-containing desensitizing agents affected the bond strength of the resin-based cements to dentin (p<0.001). PrepEze showed the highest bond strength values in all groups (p<0.001). Conclusion: Regression analysis showed a reverse relation between bond strength values of resin cements to dentin and the amount of fluoride in the desensitizing agent (p<0.05). PMID:19936532

  12. Neurological Complications in Thyroid Surgery: A Surgical Point of View on Laryngeal Nerves

    PubMed Central

    Varaldo, Emanuela; Ansaldo, Gian Luca; Mascherini, Matteo; Cafiero, Ferdinando; Minuto, Michele N.

    2014-01-01

    The cervical branches of the vagus nerve that are pertinent to endocrine surgery are the superior and the inferior laryngeal nerves: their anatomical course in the neck places them at risk during thyroid surgery. The external branch of the superior laryngeal nerve (EB) is at risk during thyroid surgery because of its close anatomical relationship with the superior thyroid vessels and the superior thyroid pole region. The rate of EB injury (which leads to the paralysis of the cricothyroid muscle) varies from 0 to 58%. The identification of the EB during surgery helps avoiding both an accidental transection and an excessive stretching. When the nerve is not identified, the ligation of superior thyroid artery branches close to the thyroid gland is suggested, as well as the abstention from an indiscriminate use of energy-based devices that might damage it. The inferior laryngeal nerve (RLN) runs in the tracheoesophageal groove toward the larynx, close to the posterior aspect of the thyroid. It is the main motor nerve of the intrinsic laryngeal muscles, and also provides sensory innervation to the larynx. Its injury finally causes the paralysis of the omolateral vocal cord and various sensory alterations: the symptoms range from mild to severe hoarseness, to acute airway obstruction, and swallowing impairment. Permanent lesions of the RNL occur from 0.3 to 7% of cases, according to different factors. The surgeon must be aware of the possible anatomical variations of the nerve, which should be actively searched for and identified. Visual control and gentle dissection of RLN are imperative. The use of intraoperative nerve monitoring has been safely applied but, at the moment, its impact in the incidence of RLN injuries has not been clarified. In conclusion, despite a thorough surgical technique and the use of intraoperative neuromonitoring, the incidence of neurological complications after thyroid surgery cannot be suppressed, but should be maintained in a low range. PMID:25076936

  13. Orienting axon growth: spinal nerve segmentation and surround-repulsion.

    PubMed

    Tannahill, D; Britto, J M; Vermeren, M M; Ohta, K; Cook, G M; Keynes, R J

    2000-01-01

    The study of spinal nerve trajectories in higher vertebrate embryos has revealed an inherent polarity within somites along the antero-posterior axis, and provides a simple system in which to study the factors that influence axon pathfinding. We argue that the orientation of spinal axons is determined by the simultaneous operation of two distinct guidance mechanisms, contact repulsion and chemorepulsion. Motor and sensory axons traverse the anterior half of each somite because they are excluded by contact repulsion from the posterior half-somite, and the molecular nature of several candidate contact repellents is reviewed. In contrast, we find that the dorsoventral trajectory of primary sensory axons is oriented by diffusible repellents originating from the notochord medially and dermamyotome laterally. In this system, therefore, repulsion by surrounding tissues ('surround-repulsion') is the main force directing axon growth in three dimensions. PMID:10761856

  14. Using the nerve stimulator for peripheral or plexus nerve blocks.

    PubMed

    Urmey, W F

    2006-06-01

    Conventional methodology for nerve location utilizes anatomical landmarks followed by invasive exploration with a needle to a suitable endpoint. An appropriate endpoint can be either anatomical in nature (e.g. transaterial technique) or functional (paresthesia or motor response to electrical stimulation). Ability to electrically stimulate a peripheral nerve or plexus depends upon many variables, including; 1) conductive area at the electrode, 2) electrical impedance, 3) electrode-to-nerve distance, 4) current flow (amperage), and 5) pulse duration. Electrode conductive area follows the equation R = rhoL/A, where R = electrical resistance, p = tissue resistivity, L = electrode-to-nerve distance, and A = electrode conductive area. Therefore resistance varies to the inverse of the electrode's conductive area. Tissue electrical impedance varies as a function of the tissue composition. In general, tissues with higher lipid content have higher impedances. Modern electrical nerve stimulators are designed to keep current constant, in spite of varying impedance. The electrode-to-nerve distance has the most influence on the ability to elicit a motor response to electrical stimulation. This is governed by Coulomb's law: E = K(Q/r2) where E = required stimulating charge, K= constant, Q = minimal required stimulating current, and r = electrode-to-nerve distance. Therefore, ability to stimulate the nerve at low amperage (e.g. < 0.5 mA), indicates an extremely close position to the nerve. Similarly, increasing current flow (amperage) increases the ability to stimulate the nerve at a distance. Increasing pulse duration increases the flow of electrons during a current pulse at any given amperage. Therefore, reducing pulse duration to very short times (e.g. 0.1 or 0.05 ms) diminishes current dispersion, requiring the needle tip to be extremely close to the nerve to elicit a motor response. The above parameters can be varied optimally to enhance successful nerve location and subsequent blockade. Unlike imaging modalities such as ultrasonography, electrical nerve stimulation depends upon nerve conduction. Similarly, percutaneous electrode guidance (PEG) makes use of the above variables to allow prelocation of the nerve by transcutaneous stimulation. PMID:16682917

  15. Antiretroviral therapy-associated acute motor and sensory axonal neuropathy.

    PubMed

    Capers, Kimberly N; Turnacioglu, Sinan; Leshner, Robert T; Crawford, John R

    2011-01-01

    Guillain-Barré syndrome (GBS) has been reported in HIV-infected patients in association with the immune reconstitution syndrome whose symptoms can be mimicked by highly active antiretroviral therapy (HAART)-mediated mitochondrial toxicity. We report a case of a 17-year-old, HIV-infected patient on HAART with a normal CD4 count and undetectable viral load, presenting with acute lower extremity weakness associated with lactatemia. Electromyography/nerve conduction studies revealed absent sensory potentials and decreased compound muscle action potentials, consistent with a diagnosis of acute motor and sensory axonal neuropathy. Lactatemia resolved following cessation of HAART; however, neurological deficits minimally improved over several months in spite of immune modulatory therapy. This case highlights the potential association between HAART, mitochondrial toxicity and acute axonal neuropathies in HIV-infected patients, distinct from the immune reconstitution syndrome. PMID:21327178

  16. Facial nerve neuromas: radiologic evaluation.

    PubMed

    Latack, J T; Gabrielsen, T O; Knake, J E; Kemink, J L; Graham, M D; Gebarski, S S; Yang, P J

    1983-12-01

    Eight patients who had facial nerve neuromas were examined, and the radiographic findings are reported. Thin section tomography, high resolution computed tomography, posterior fossa computed tomography, and cerebellopontine angle cisternography using Pantopaque (iophendylate) demonstrated bone erosions and soft tissue masses conforming to the course of the facial nerve. The lesions generally exhibited either a proximal or a distal pattern of nerve involvement. Radiologic imaging frequently permits a correct preoperative diagnosis and accurate definition of the extent of facial nerve neuromas, assessments that are important for proper patient management. PMID:6606188

  17. Reduced myelinated fiber size correlates with loss of axonal neurofilaments in peripheral nerve of chronically streptozotocin diabetic rats.

    PubMed Central

    Yagihashi, S.; Kamijo, M.; Watanabe, K.

    1990-01-01

    Peripheral sensory nerve abnormalities were investigated in long-term streptozotocin diabetic rats using quantitative analysis. To determine whether the characteristic structural changes occur with a proximodistal gradient, three levels of the sensory peripheral nervous system were investigated: the postganglionic segment of the dorsal root, the midportion of the sciatic nerve, and the distal sural nerve. Reduction of myelinated fiber size due to reduced axonal caliber was the most characteristic change at both proximal and distal levels of the peripheral nerve. The relationship between axonal size and myelin spiral length indicated a more severe axonal atrophy in the distal portion. The axonal atrophy was related to a proportional loss of axonal neurofilaments at proximal levels, whereas in the distal sural nerve the loss of neurofilaments exceeded that which would be expected for axonal size. The universal reduction of axonal size in diabetic nerve may be accounted for by impaired supply of neurofilaments or reduced neurofilament synthesis. Such cytoskeletal defects may, in turn, lead to distal axonal degeneration or contribute to the susceptibility of diabetic nerve to various external noxi, including ischemia and hypoglycemia. PMID:2141449

  18. P2Y1 purinergic receptors in sensory neurons: contribution to touch-induced impulse generation.

    PubMed Central

    Nakamura, F; Strittmatter, S M

    1996-01-01

    Somatic sensation requires the conversion of physical stimuli into the depolarization of distal nerve endings. A single cRNA derived from sensory neurons renders Xenopus laevis oocytes mechanosensitive and is found to encode a P2Y1 purinergic receptor. P2Y1 mRNA is concentrated in large-fiber dorsal root ganglion neurons. In contrast, P2X3 mRNA is localized to small-fiber sensory neurons and produces less mechanosensitivity in oocytes. The frequency of touch-induced action potentials from frog sensory nerve fibers is increased by the presence of P2 receptor agonists at the peripheral nerve ending and is decreased by the presence of P2 antagonists. P2X-selective agents do not have these effects. The release of ATP into the extracellular space and the activation of peripheral P2Y1 receptors appear to participate in the generation of sensory action potentials by light touch. Images Fig. 4 Fig. 5 PMID:8816824

  19. Analysis and Measurement of the Sympathetic and Sensory Innervation of White and Brown Adipose Tissue

    PubMed Central

    Vaughan, Cheryl H.; Zarebidaki, Eleen; Ehlen, J. Christopher; Bartness, Timothy J.

    2014-01-01

    Here, we provide a detailed account of how to denervate white and brown adipose tissue (WAT and BAT) and how to measure sympathetic nervous system (SNS) activity to these and other tissues neurochemically. The brain controls many of the functions of WAT and BAT via the SNS innervation of the tissues, especially lipolysis and thermogenesis, respectively. There is no clearly demonstrated parasympathetic innervation of WAT or the major interscapular BAT (IBAT) depot. WAT and BAT communicate with the brain neurally via sensory nerves. We detail the surgical denervation (eliminating both innervations) of several WAT pads and IBAT. We also detail more selective chemical denervation of the SNS innervation via intra-WAT/IBAT 6-hydroxy-dopamine (a catecholaminergic neurotoxin) injections and selective chemical sensory denervation via intra-WAT/IBAT capsaicin (a sensory nerve neurotoxin) injections. Verifications of the denervations are provided (HPLC-EC detection for SNS, ELIA for calcitonin gene-related peptide (proven sensory nerve marker)). Finally, assessment of the SNS drive to WAT/BAT or other tissues is described using the alpha-methyl-para-tyrosine method combined with HPLC-EC, a direct neurochemical measure of SNS activity. These methods have proven useful for us and for other investigators interested in innervation of adipose tissues. The chemical denervation approach has been extended to nonadipose tissues as well. PMID:24480348

  20. Cross-Excitation in Peripheral Sensory Ganglia Associated with Pain Transmission

    PubMed Central

    Omoto, Katsuhiro; Maruhama, Kotaro; Terayama, Ryuji; Yamamoto, Yumiko; Matsushita, Osamu; Sugimoto, Tomosada; Oguma, Keiji; Matsuka, Yoshizo

    2015-01-01

    Despite the absence of synaptic contacts, cross-excitation of neurons in sensory ganglia during signal transmission is considered to be chemically mediated and appears increased in chronic pain states. In this study, we modulated neurotransmitter release in sensory neurons by direct application of type A botulinum neurotoxin (BoNT/A) to sensory ganglia in an animal model of neuropathic pain and evaluated the effect of this treatment on nocifensive. Unilateral sciatic nerve entrapment (SNE) reduced the ipsilateral hindpaw withdrawal threshold to mechanical stimulation and reduced hindpaw withdrawal latency to thermal stimulation. Direct application of BoNT/A to the ipsilateral L4 dorsal root ganglion (DRG) was localized in the cell bodies of the DRG and reversed the SNE-induced decreases in withdrawal thresholds within 2 days of BoNT/A administration. Results from this study suggest that neurotransmitter release within sensory ganglia is involved in the regulation of pain-related signal transmission. PMID:26248078

  1. Cranial nerve fasciculation and Schwann cell migration are impaired after loss of Npn-1.

    PubMed

    Huettl, Rosa-Eva; Huber, Andrea B

    2011-11-15

    Interaction of the axon guidance receptor Neuropilin-1 (Npn-1) with its repulsive ligand Semaphorin 3A (Sema3A) is crucial for guidance decisions, fasciculation, timing of growth and axon-axon interactions of sensory and motor projections in the embryonic limb. At cranial levels, Npn-1 is expressed in motor neurons and sensory ganglia and loss of Sema3A-Npn-1 signaling leads to defasciculation of the superficial projections to the head and neck. The molecular mechanisms that govern the initial fasciculation and growth of the purely motor projections of the hypoglossal and abducens nerves in general, and the role of Npn-1 during these events in particular are, however, not well understood. We show here that selective removal of Npn-1 from somatic motor neurons impairs initial fasciculation and assembly of hypoglossal rootlets and leads to reduced numbers of abducens and hypoglossal fibers. Ablation of Npn-1 specifically from cranial neural crest and placodally derived sensory tissues recapitulates the distal defasciculation of mixed sensory-motor nerves of trigeminal, facial, glossopharyngeal and vagal projections, which was observed in Npn-1(-/-) and Npn-1(Sema-) mutants. Surprisingly, the assembly and fasciculation of the purely motor hypoglossal nerve are also impaired and the number of Schwann cells migrating along the defasciculated axonal projections is reduced. These findings are corroborated by partial genetic elimination of cranial neural crest and embryonic placodes, where loss of Schwann cell precursors leads to aberrant growth patterns of the hypoglossal nerve. Interestingly, rostral turning of hypoglossal axons is not perturbed in any of the investigated genotypes. Thus, initial hypoglossal nerve assembly and fasciculation, but not later guidance decisions depend on Npn-1 expression and axon-Schwann cell interactions. PMID:21925156

  2. Sympathetic Nerve Fibers in Human Cervical and Thoracic Vagus Nerves

    PubMed Central

    Seki, Atsuko; Green, Hunter R.; Lee, Thomas D.; Hong, LongSheng; Tan, Jian; Vinters, Harry V.; Chen, Peng-Sheng; Fishbein, Michael C.

    2014-01-01

    Background Vagus nerve stimulation therapy (VNS) has been used for chronic heart failure (CHF), and is believed to improve imbalance of autonomic control by increasing parasympathetic activity. Although it is known that there is neural communication between the VN and the cervical sympathetic trunk, there are few data regarding the quantity and/or distribution of the sympathetic components within the VN. Objective To examine the sympathetic component within human VN and correlate these with the presence of cardiac and neurologic diseases. Methods We performed immunohistochemistry on 31 human cervical and thoracic VNs (total 104 VNs) from autopsies and we reviewed the patients’ records. We correlated the quantity of sympathetic nerve fibers within the VNs with cardiovascular and neurologic disease states. Results All 104 VNs contain TH positive (sympathetic) nerve fibers; the mean TH positive areas were 5.47% in right cervical, 3.97% in left cervical, 5.11% in right thoracic, and 4.20% in left thoracic VN. The distribution of TH positive nerve fibers varied from case to case: central, peripheral, or scattered throughout nerve bundles. No statistically significant differences in nerve morphology were seen between diseases in which VNS is considered effective (depression and CHF), and other cardiovascular diseases, or neurodegenerative disease. Conclusion Human VNs contain sympathetic nerve fibers. The sympathetic component within the VN could play a role in physiologic effects reported with VNS. The recognition of sympathetic nerve fibers in the VNs may lead to better understanding of the therapeutic mechanisms of VNS. PMID:24768897

  3. Nerve-pulse interactions

    SciTech Connect

    Scott, A.C.

    1982-01-01

    Some recent experimental and theoretical results on mechanisms through which individual nerve pulses can interact are reviewed. Three modes of interactions are considered: (1) interaction of pulses as they travel along a single fiber which leads to velocity dispersion; (2) propagation of pairs of pulses through a branching region leading to quantum pulse code transformations; and (3) interaction of pulses on parallel fibers through which they may form a pulse assembly. This notion is analogous to Hebb's concept of a cell assembly, but on a lower level of the neural hierarchy.

  4. Cranial Nerve Development Requires Co-Ordinated Shh and Canonical Wnt Signaling

    PubMed Central

    Kurosaka, Hiroshi; Trainor, Paul A.; Leroux-Berger, Margot; Iulianella, Angelo

    2015-01-01

    Cranial nerves govern sensory and motor information exchange between the brain and tissues of the head and neck. The cranial nerves are derived from two specialized populations of cells, cranial neural crest cells and ectodermal placode cells. Defects in either cell type can result in cranial nerve developmental defects. Although several signaling pathways are known to regulate cranial nerve formation our understanding of how intercellular signaling between neural crest cells and placode cells is coordinated during cranial ganglia morphogenesis is poorly understood. Sonic Hedgehog (Shh) signaling is one key pathway that regulates multiple aspects of craniofacial development, but whether it co-ordinates cranial neural crest cell and placodal cell interactions during cranial ganglia formation remains unclear. In this study we examined a new Patched1 (Ptch1) loss-of-function mouse mutant and characterized the role of Ptch1 in regulating Shh signaling during cranial ganglia development. Ptch1Wig/ Wig mutants exhibit elevated Shh signaling in concert with disorganization of the trigeminal and facial nerves. Importantly, we discovered that enhanced Shh signaling suppressed canonical Wnt signaling in the cranial nerve region. This critically affected the survival and migration of cranial neural crest cells and the development of placodal cells as well as the integration between neural crest and placodes. Collectively, our findings highlight a novel and critical role for Shh signaling in cranial nerve development via the cross regulation of canonical Wnt signaling. PMID:25799573

  5. Stem cells and related factors involved in facial nerve function regeneration.

    PubMed

    Nelke, Kamil H; ?uczak, Klaudiusz; Pawlak, Wojciech; ?ysenko, Lidia; Gerber, Hanna

    2015-01-01

    The facial nerve (VII) is one of the most important cranial nerves for head and neck surgeons. Its function is closely related to facial expressions that are individual for every person. After its injury or palsy, its functions can be either impaired or absent. Because of the presence of motor, sensory and parasympathetic fibers, the biology of its repair and function restoration depends on many factors. In order to achieve good outcome, many different therapies can be performed in order to restore as much of the nerve function as possible. When rehabilitation and physiotherapy are not sufficient, additional surgical procedures and therapies are taken into serious consideration. The final outcome of many of them is discussable, depending on nerve damage etiology. Stem cells in facial nerve repair are used, but long-term outcomes and results are still not fully known. In order to understand this therapeutic approach, clinicians and surgeons should understand the immunobiology of nerve repair and regeneration. In this review, potential stem cell usage in facial nerve regeneration procedures is discussed. PMID:26400886

  6. Corneal Confocal Microscopy Detects Early Nerve Regeneration in Diabetic Neuropathy After Simultaneous Pancreas and Kidney Transplantation

    PubMed Central

    Tavakoli, Mitra; Mitu-Pretorian, Maria; Petropoulos, Ioannis N.; Fadavi, Hassan; Asghar, Omar; Alam, Uazman; Ponirakis, Georgios; Jeziorska, Maria; Marshall, Andy; Efron, Nathan; Boulton, Andrew J.; Augustine, Titus; Malik, Rayaz A.

    2013-01-01

    Diabetic neuropathy is associated with increased morbidity and mortality. To date, limited data in subjects with impaired glucose tolerance and diabetes demonstrate nerve fiber repair after intervention. This may reflect a lack of efficacy of the interventions but may also reflect difficulty of the tests currently deployed to adequately assess nerve fiber repair, particularly in short-term studies. Corneal confocal microscopy (CCM) represents a novel noninvasive means to quantify nerve fiber damage and repair. Fifteen type 1 diabetic patients undergoing simultaneous pancreas–kidney transplantation (SPK) underwent detailed assessment of neurologic deficits, quantitative sensory testing (QST), electrophysiology, skin biopsy, corneal sensitivity, and CCM at baseline and at 6 and 12 months after successful SPK. At baseline, diabetic patients had a significant neuropathy compared with control subjects. After successful SPK there was no significant change in neurologic impairment, neurophysiology, QST, corneal sensitivity, and intraepidermal nerve fiber density (IENFD). However, CCM demonstrated significant improvements in corneal nerve fiber density, branch density, and length at 12 months. Normalization of glycemia after SPK shows no significant improvement in neuropathy assessed by the neurologic deficits, QST, electrophysiology, and IENFD. However, CCM shows a significant improvement in nerve morphology, providing a novel noninvasive means to establish early nerve repair that is missed by currently advocated assessment techniques. PMID:23002037

  7. Fluorescently-tagged anti-ganglioside antibody selectively identifies peripheral nerve in living animals

    PubMed Central

    Massaad, Cynthia A.; Zhang, Gang; Pillai, Laila; Azhdarinia, Ali; Liu, Weiqiang; Sheikh, Kazim A.

    2015-01-01

    Selective in vivo delivery of cargo to peripheral nervous system (PNS) has broad clinical and preclinical applications. An important applicability of this approach is systemic delivery of fluorescently conjugated ligands that selectively label PNS, which could allow visualization of peripheral nerves during any surgery. We examine the use of an anti-ganglioside monoclonal antibody (mAb) as selective neuronal delivery vector for surgical imaging of peripheral nerves. Systemic delivery of an anti-ganglioside mAb was used for selective intraneuronal/axonal delivery of fluorescent agents to visualize nerves by surgical imaging in living mice. In this study, we show that intact motor, sensory, and autonomic nerve fibers/paths are distinctly labeled following a single nanomolar systemic injection of fluorescently labeled anti-ganglioside mAb. Tissue biodistribution studies with radiolabeled mAb were used to validate neuronal uptake of fluorescently labeled mAb. Implications of this proof of concept study are that fluorescent conjugates of anti-ganglioside mAbs are valuable delivery vectors to visualize nerves during surgery to avoid nerve injury and monitor nerve degeneration and regeneration after injury. These findings support that antibodies, and their derivatives/fragments, can be used as selective neuronal delivery vector for transport of various cargos to PNS in preclinical and clinical settings. PMID:26514366

  8. ASM-024, a Piperazinium Compound, Promotes the In Vitro Relaxation of ?2-Adrenoreceptor Desensitized Tracheas

    PubMed Central

    Israël-Assayag, Evelyne; Beaulieu, Marie-Josée; Cormier, Yvon

    2015-01-01

    Inhaled ?2-adrenoreceptor agonists are widely used in asthma and chronic obstructive pulmonary disease (COPD) for bronchoconstriction relief. ?2-adrenoreceptor agonists relax airway smooth muscle cells via cyclic adenosine monophosphate (cAMP) mediated pathways. However, prolonged stimulation induces functional desensitization of the ?2-adrenoreceptors (?2-AR), potentially leading to reduced clinical efficacy with chronic or prolonged administration. ASM-024, a small synthetic molecule in clinical stage development, has shown activity at the level of nicotinic receptors and possibly at the muscarinic level and presents anti-inflammatory and bronchodilator properties. Aerosolized ASM-024 reduces airway resistance in mice and promotes in-vitro relaxation of tracheal and bronchial preparations from animal and human tissues. ASM-024 increased in vitro relaxation response to maximally effective concentration of short—acting beta-2 agonists in dog and human bronchi. Although the precise mechanisms by which ASM-024 promotes airway smooth muscle (ASM) relaxation remain unclear, we hypothesized that ASM-024 will attenuate and/or abrogate agonist-induced contraction and remain effective despite ?2-AR tachyphylaxis. ?2-AR tachyphylaxis was induced with salbutamol, salmeterol and formoterol on guinea pig tracheas. The addition of ASM-024 relaxed concentration-dependently intact or ?2-AR desensitized tracheal rings precontracted with methacholine. ASM-024 did not induce any elevation of intracellular cAMP in isolated smooth muscle cells; moreover, blockade of the cAMP pathway with an adenylate cyclase inhibitor had no significant effect on ASM-024-induced guinea pig trachea relaxation. Collectively, these findings show that ASM-024 elicits relaxation of ?2-AR desensitized tracheal preparations and suggest that ASM-024 mediates smooth muscle relaxation through a different target and signaling pathway than ?2-adrenergic receptor agonists. These findings suggest ASM-024 could potentially provide clinical benefit when used adjunctively with inhaled ?2-adrenoreceptor agonists in those patients exhibiting a reduced response to their chronic use. PMID:25799096

  9. The cholesterol dependence of activation and fast desensitization of the nicotinic acetylcholine receptor.

    PubMed Central

    Rankin, S E; Addona, G H; Kloczewiak, M A; Bugge, B; Miller, K W

    1997-01-01

    When nicotinic acetylcholine receptors are reconstituted into lipid bilayers lacking cholesterol, agonists no longer stimulate cation flux. The kinetics of this process are difficult to study because variations in vesicle morphology cause errors in flux measurements. We developed a new stopped-flow fluorescence assay to study activation independently of vesicle morphology. When receptors were rapidly mixed with agonist plus ethidium, the earliest fluorescence increase reported the fraction of channels that opened and their apparent rate of fast desensitization. These processes were absent when the receptor was reconstituted into dioleoylphosphatidylcholine or into a mixture of that lipid with dioleoylphosphatidic acid (12 mol%), even though a fluorescent agonist reported that resting-state receptors were still present. The agonist-induced channel opening probability increased with bilayer cholesterol, with a midpoint value of 9 +/- 1.7 mol% and a Hill coefficient of 1.9 +/- 0.69, reaching a plateau above 20-30 mol% cholesterol that was equal to the native value. On the other hand, the observed fast desensitization rate was comparable to that for native membranes from the lowest cholesterol concentration examined (5 mol%). Thus the ability to reach the open state after activation varies with the cholesterol concentration in the bilayer, whereas the rate of the open state to fast desensitized state transition is unaffected. The structural basis for this is unknown, but an interesting corollary is that the channels of newly synthesized receptors are not fully primed by cholesterol until they are inserted into the plasma membrane--a novel form of posttranslational processing. PMID:9370438

  10. Managing Chemotherapy Side Effects: Nerve Changes

    MedlinePLUS

    ... anD human services national institutes of health Managing Chemotherapy Side Effects Nerve Changes “My fingers and toes ... I always wore shoes.” About nerve changes Some chemotherapy can cause nerve problems. You may have a ...

  11. A complex sensory organ in the nose skin of the prosimian primate Lemur catta.

    PubMed

    Elofsson, Rolf; Tuminaite, Inga; Kröger, Ronald H H

    2015-06-01

    Most mammals have nose tips covered by glabrous skin, a labronasal area, or rhinarium. The surface of the rhinarium of Lemur catta has a dermatoglyphic pattern consisting of epidermal domes. Below the domes, epidermal pegs dip down into the dermis. In and below the tip of the epidermal peg, a complex sensory organ is found. It consists of an association of innervated Merkel cells, lamellate (Pacini-like) bodies with a central nerve, and a ring of unmyelinated nerve endings in the epidermis. The Merkel cells are situated basally in the epidermis and the lamellated bodies just below the epidermis. The unmyelinated nerve endings related to the organ ascend in a circle straight through the epidermis ending below the corneal layer. From these nerve terminals, horizontal spikes enter the keratinocytes. The three components occur together forming an organ and are innervated from a common nerve plexus. The morphology of the complex sensory organ of the lemur shares most crucial components with Eimer's organs in moles, echidna, and platypus, while some structures are lacking, for example, the specific central pillar of keratinocytes, the cuticular cap, and a central unmyelinated fiber. The presence of the essentials of an Eimer's organ in many mammals suggests that a wider definition is motivated. PMID:25645577

  12. Expression of fibrinogen receptors during activation and subsequent desensitization of human platelets by epinephrine.

    PubMed

    Shattil, S J; Motulsky, H J; Insel, P A; Flaherty, L; Brass, L F

    1986-12-01

    Epinephrine causes platelet aggregation and secretion by interacting with alpha 2-adrenergic receptors on the platelet surface. Platelet aggregation requires the binding of fibrinogen to a specific receptor on the membrane glycoprotein IIb-IIIa complex. Although the IIb-IIIa complex is identifiable on the surface of resting platelets, the fibrinogen receptor is expressed only after platelet activation. The current studies were designed to examine the effect of occupancy of platelet alpha 2-adrenergic receptors by epinephrine on the expression of fibrinogen receptors and on the aggregation of platelets. The ability of epinephrine to induce the expression of fibrinogen receptors was studied under two different conditions: acute stimulation (less than 1 min) and prolonged stimulation (50 to 90 min), the latter of which is associated with a reduction or "desensitization" of the platelet aggregation response. Expression of the fibrinogen receptor was monitored with 125I-fibrinogen as well as with 125I-PAC-1 (PAC-1), a monoclonal antibody that binds to the glycoprotein IIb-IIIa complex only after platelets are activated. Epinephrine caused an immediate increase in PAC-1 and fibrinogen binding that was dependent on occupancy of the alpha 2-receptor by epinephrine and on the presence of extracellular free Ca (KCa = 30 mumol/L). By itself, 1 mmol/L Mg was unable to support induction of the fibrinogen receptor by epinephrine. However, it did decrease the Ca requirement by about two orders of magnitude. Prolonged stimulation of unstirred platelets by epinephrine led to a 70% decrease in the aggregation response when the platelets were subsequently stirred. Despite their decreased aggregation response, desensitized platelets bound PAC-1 and fibrinogen normally, indicating that the loss of aggregation was not due simply to a decrease in fibrinogen receptor expression. Although desensitization was not affected by pretreatment of the platelets with aspirin, it was partially prevented when extracellular Ca was chelated by EDTA during the long incubation with epinephrine. These studies demonstrate that once platelet alpha 2-adrenergic receptors are occupied by epinephrine, extracellular Ca is involved in initiating the aggregation response by supporting the induction of the fibrinogen receptor and the binding of fibrinogen. Furthermore. Ca-dependent reactions subsequent to fibrinogen binding may be necessary for maximal platelet aggregation and are impaired when platelets become desensitized to epinephrine. PMID:3779100

  13. Comparison of effect of desensitizing agents on the retention of crowns cemented with luting agents: an in vitro study

    PubMed Central

    Pandharinath, Dange Shankar; Arun, Khalikar; Smita, Vaidya

    2012-01-01

    PURPOSE Many dentists use desensitizing agents to prevent hypersensitivity. This study compared and evaluated the effect of two desensitizing agents on the retention of cast crowns when cemented with various luting agents. MATERIALS AND METHODS Ninety freshly extracted human molars were prepared with flat occlusal surface, 6 degree taper and approximately 4 mm axial length. The prepared specimens were divided into 3 groups and each group is further divided into 3 subgroups. Desensitizing agents used were GC Tooth Mousse and GLUMA® desensitizer. Cementing agents used were zinc phosphate, glass ionomer and resin modified glass ionomer cement. Individual crowns with loop were made from base metal alloy. Desensitizing agents were applied before cementation of crowns except for control group. Under tensional force the crowns were removed using an automated universal testing machine. Statistical analysis included one-way ANOVA followed by Turkey-Kramer post hoc test at a preset alpha of 0.05. RESULTS Resin modified glass ionomer cement exhibited the highest retentive strength and all dentin treatments resulted in significantly different retentive values (In Kg.): GLUMA (49.02 ± 3.32) > Control (48.61 ± 3.54) > Tooth mousse (48.34 ± 2.94). Retentive strength for glass ionomer cement were GLUMA (41.14 ± 2.42) > Tooth mousse (40.32 ± 3.89) > Control (39.09 ± 2.80). For zinc phosphate cement the retentive strength were lowest GLUMA (27.92 ± 3.20) > Control (27.69 ± 3.39) > Tooth mousse (25.27 ± 4.60). CONCLUSION The use of GLUMA® desensitizer has no effect on crown retention. GC Tooth Mousse does not affect the retentive ability of glass ionomer and resin modified glass ionomer cement, but it decreases the retentive ability of zinc phosphate cement. PMID:22977719

  14. Desensitization of AMPA receptors and AMPA-NMDA receptor interaction: an in vivo cyclic GMP microdialysis study in rat cerebellum.

    PubMed Central

    Fedele, E.; Raiteri, M.

    1996-01-01

    1. Desensitization is an important characteristic of glutamate receptors of the alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA) type. 2. Stimulation of N-methyl-D-aspartate (NMDA) or AMPA receptors in cerebellum results in increased production of cyclic GMP. We have investigated AMPA receptor desensitization in vivo by monitoring extracellular cyclic GMP during intracerebellar microdialysis in conscious unrestrained adult rats. 3. Local infusion of AMPA (10 to 100 microM) caused dose-related elevations of cyclic GMP levels. The effect of AMPA was prevented by the non-NMDA receptor antagonist, 6,7-dinitroquinoxaline-2,3-dione (DNQX) and by the nitric oxide (NO) synthase inhibitor NG-nitro-L-arginine (L-NOARG). 4. In the absence of AMPA, DNQX lowered the basal levels of cyclic GMP whereas the NMDA receptor channel antagonist dizocilpine (MK-801) was ineffective. 5. Cyclothiazide, a blocker of AMPA receptor desensitization, potentiated the cyclic GMP response to exogenous AMPA. Moreover, cyclothiazide (100-300 microM) produced on its own dose-dependent elevations of extracellular cyclic GMP. The cyclothiazide-induced response was prevented not only by DNQX but also by MK-801. 6. While the cyclic GMP response elicited by AMPA was totally insensitive to MK-801, the response produced by AMPA (10 microM) plus cyclothiazide (30 microM) was strongly attenuated by the NMDA receptor antagonist (30 microM). 7. The results suggest that (a) AMPA receptors linked to the NO-cyclic GMP pathway in the cerebellum can undergo desensitization in vivo during exposure to exogenous AMPA; cyclothiazide inhibits such desensitization; (b) AMPA receptors (but not NMDA receptors) are 'tonically' activated and kept in a partly desensitized state by endogenous glutamate; (c) if cyclothiazide is present, activation of AMPA receptors may permit endogenous activation of NMDA receptors. PMID:8882607

  15. The subgenual organ complex in the cave cricket Troglophilus neglectus (Orthoptera: Rhaphidophoridae): comparative innervation and sensory evolution.

    PubMed

    Strauß, Johannes; Stritih, Nataša; Lakes-Harlan, Reinhard

    2014-10-01

    Comparative studies of the organization of nervous systems and sensory organs can reveal their evolution and specific adaptations. In the forelegs of some Ensifera (including crickets and tettigoniids), tympanal hearing organs are located in close proximity to the mechanosensitive subgenual organ (SGO). In the present study, the SGO complex in the non-hearing cave cricket Troglophilus neglectus (Rhaphidophoridae) is investigated for the neuronal innervation pattern and for organs homologous to the hearing organs in related taxa. We analyse the innervation pattern of the sensory organs (SGO and intermediate organ (IO)) and its variability between individuals. In T. neglectus, the IO consists of two major groups of closely associated sensilla with different positions. While the distal-most sensilla superficially resemble tettigoniid auditory sensilla in location and orientation, the sensory innervation does not show these two groups to be distinct organs. Though variability in the number of sensory nerve branches occurs, usually either organ is supplied by a single nerve branch. Hence, no sensory elements clearly homologous to the auditory organ are evident. In contrast to other non-hearing Ensifera, the cave cricket sensory structures are relatively simple, consistent with a plesiomorphic organization resembling sensory innervation in grasshoppers and stick insects. PMID:26064547

  16. The subgenual organ complex in the cave cricket Troglophilus neglectus (Orthoptera: Rhaphidophoridae): comparative innervation and sensory evolution

    PubMed Central

    Strauß, Johannes; Stritih, Nataša; Lakes-Harlan, Reinhard

    2014-01-01

    Comparative studies of the organization of nervous systems and sensory organs can reveal their evolution and specific adaptations. In the forelegs of some Ensifera (including crickets and tettigoniids), tympanal hearing organs are located in close proximity to the mechanosensitive subgenual organ (SGO). In the present study, the SGO complex in the non-hearing cave cricket Troglophilus neglectus (Rhaphidophoridae) is investigated for the neuronal innervation pattern and for organs homologous to the hearing organs in related taxa. We analyse the innervation pattern of the sensory organs (SGO and intermediate organ (IO)) and its variability between individuals. In T. neglectus, the IO consists of two major groups of closely associated sensilla with different positions. While the distal-most sensilla superficially resemble tettigoniid auditory sensilla in location and orientation, the sensory innervation does not show these two groups to be distinct organs. Though variability in the number of sensory nerve branches occurs, usually either organ is supplied by a single nerve branch. Hence, no sensory elements clearly homologous to the auditory organ are evident. In contrast to other non-hearing Ensifera, the cave cricket sensory structures are relatively simple, consistent with a plesiomorphic organization resembling sensory innervation in grasshoppers and stick insects. PMID:26064547

  17. Head sensory organs of Dactylopodola baltica (Macrodasyida, Gastrotricha): a combination of transmission electron microscopical and immunocytochemical techniques.

    PubMed

    Liesenjohann, Thilo; Neuhaus, Birger; Schmidt-Rhaesa, Andreas

    2006-08-01

    The anterior and posterior head sensory organs of Dactylopodola baltica (Macrodasyida, Gastrotricha) were investigated by transmission electron microscopy (TEM). In addition, whole individuals were labeled with phalloidin to mark F-actin and with anti-alpha-tubulin antibodies to mark microtubuli and studied with confocal laser scanning microscopy. Immunocytochemistry reveals that the large number of ciliary processes in the anterior head sensory organ contain F-actin; no signal could be detected for alpha-tubulin. Labeling with anti-alpha-tubulin antibodies revealed that the anterior and posterior head sensory organs are innervated by a common stem of nerves from the lateral nerve cords just anterior of the dorsal brain commissure. TEM studies showed that the anterior head sensory organ is composed of one sheath cell and one sensory cell with a single branching cilium that possesses a basal inflated part and regularly arranged ciliary processes. Each ciliary process contains one central microtubule. The posterior head sensory organ consists of at least one pigmented sheath cell and several probably monociliary sensory cells. Each cilium branches into irregularly arranged ciliary processes. These characters are assumed to belong to the ground pattern of the Gastrotricha. PMID:16739161

  18. Peripheral site of action of levodropropizine in experimentally-induced cough: role of sensory neuropeptides.

    PubMed

    Lavezzo, A; Melillo, G; Clavenna, G; Omini, C

    1992-06-01

    The mechanism of action of levodropropizine has been investigated in different models of experimentally-induced cough in guinea-pigs. In particular it has been demonstrated that the antitussive drug has a peripheral site of action by injecting the drug intracerebroventricularly (i.c.v.). In these experiments levodropropizine (40 micrograms/50 microliters i.c.v.) did not prevent electrically-induced cough. On the other hand, codeine (5 micrograms/50 microliters i.c.v.) markedly prevented coughing. A difference in the potency ratio of levodropropizine and codeine has been demonstrated in capsaicin-induced cough; after oral administration, codeine was about two to three times more potent than levodropropizine. However, after aerosol administration the two compounds were equipotent. These data might suggest a peripheral site of action for levodropropizine which is related to sensory neuropeptides. Further support for the role of sensory neuropeptides in the mechanism of action of levodropropizine comes from the results obtained in capsaicin-desensitized animals. In this experimental model levodropropizine failed to prevent the vagally elicited cough in neuropeptide-depleted animals, whereas codeine did not differentiate between control and capsaicin-treated animals. In conclusion, our results support the suggestion that levodropropizine has a peripheral site of action. In addition, the interference with the sensory neuropeptide system may explain, at least in part, its activity in experimentally-induced cough. PMID:1611233

  19. Evaluation and use of regenerative multi electrode interfaces in peripheral nerves

    NASA Astrophysics Data System (ADS)

    Desai, Vidhi

    Peripheral nerves offer unique accessibility to the innate motor and sensory pathways that can be interfaced with high degree of selectivity for intuitive and bidirectional control of advanced upper extremity prosthetic limbs. Several peripheral nerve interfaces have been proposed and investigated over the last few decades with significant progress made in the area of sensory feedback. However, clinical translation still remains a formidable challenge due to the lack of long term recordings. Prominent causes include signal degradation, eventual interface failures, and lack of specificity in the low amplitude nerve signals. This dissertation evaluates the capabilities of the newly developed Regenerative Multi-electrode Interface (REMI) by the characterization of signal quality progression, the identification of interfaced axon types, and the demonstration of "functional linkage" between acquired signals and target organs. Chapter 2 details the chronic recording of high quality signals from REMI in sciatic nerve which remained stable over a 120 day implantation period indicative of minimal ongoing tissue response with no detrimental effects on the recording ability. The dominant cause of failures was attributable to abiotic factors pertaining to the connector/wire breakage, observed in 76% of REMI implants. Also, the REMI implants had 20% higher success rate and significantly larger Signal to Noise Ratio (SNR) in comparison to the Utah Slanted Electrode Array (USEA). Chapter 3 describes the successful feasibility of interfacing with motor and sensory axons by REMI implantation in the tibial and sural fascicles of the sciatic nerve. A characteristic sampling bias towards recording signals from medium-to-large diameter axons that are primarily involved in mechanoception and proprioception sensory functions was uncovered. Specific bursting units (Inter Spike Interval of 30-70ms) were observed most frequently from the tibial fascicle during bipedal locomotion. Chapter 4 explores the discrimination between motor and proprioceptive origin of this bursting activity and reports the identified efferent motor nature, as well as the demonstration of a significant and stable correlation with the activity of distal muscle involved in locomotion. In summary, sensory-motor neural activity was recorded chronically by REMI electrodes with high SNR which serves as a tool for evaluating firing patterns of specific axon types during voluntary movement or sensory stimulation. In turn, this interface can be used to improve motor control and sensory feedback in closed loop systems for robotic prosthesis.

  20. Functions of the Renal Nerves.

    ERIC Educational Resources Information Center

    Koepke, John P.; DiBona, Gerald F.

    1985-01-01

    Discusses renal neuroanatomy, renal vasculature, renal tubules, renin secretion, renorenal reflexes, and hypertension as related to renal nerve functions. Indicates that high intensitites of renal nerve stimulation have produced alterations in several renal functions. (A chart with various stimulations and resultant renal functions and 10-item,…

  1. Persistent postoperative pain and sensory changes following lymph node excision in melanoma patients: a topical review.

    PubMed

    Slagelse, Charlotte; Petersen, Karin L; Dahl, Jřrgen B; Finnerup, Kenneth; Greene, Kaitlin; Leong, Stanley P; Levine, Jon; Rowbotham, Michael; Werner, Mads U; Finnerup, Nanna B

    2014-04-01

    Studies on complications related to chronic nerve injury following sentinel lymph node biopsy (SLNB) and complete lymph node dissection (CLND) for melanoma are sparse. This review summarizes the existing literature on pain and neuropathic complications in melanoma patients undergoing SLNB with or without CLND. The Cochrane Central Register of Controlled Trials and the Embase and PubMed databases were searched. Full-text English language articles published before June 2013 were included. Prospective and retrospective studies assessing persistent (>1 month) sensory nerve injury, postoperative pain, neuropathic pain, and sensory disturbances following SLNB with or without CLND in melanoma patients were eligible. Nine studies (six prospective and three retrospective) including data for 3632 patients met our inclusion criteria. Outcome parameters were too heterogeneous to conduct a quantitative analysis, and few studies systematically evaluated pain and sensory abnormalities. Persistent postoperative pain was reported in 1-14% of patients following SLNB and in 6-34% following CLND and sensory abnormalities in 0.1-32 and 2-82%, respectively. In the one study that assessed the type of pain, neuropathic pain was suggested to explain persistent pain in 31-66% of patients with SLNB and 82-89% of patients with CLND. Sensory-nerve-related complications in melanoma patients seem to be less pronounced following SLNB compared with CLND. Prospective observational studies are necessary to identify predictors of persistent pain, to evaluate the prevalence and impact of pain and sensory abnormalities, and to develop strategies for prevention of long-term complications. PMID:24346167

  2. Age-dependent effects on sensory axonal excitability in normal mice.

    PubMed

    Banzrai, Chimeglkham; Nodera, Hiroyuki; Higashi, Saki; Okada, Ryo; Osaki, Yusuke; Mori, Atsuko; Kaji, Ryuji

    2016-01-12

    Serial recordings were performed to measure sensory excitability in peripheral nerves and elucidate age-dependent changes in neuronal ion currents in the peripheral sensory nervous system. The threshold tracking technique was used to measure multiple excitability indices in the tail sensory nerves of five normal male mice at four time points (6, 10, 14, and 19 weeks of age). A separate group of four mice was also measured at 43 weeks and at 60 weeks of age. Maturation was accompanied by an increase in early hyperpolarization and superexcitability at 10 weeks. At 60 weeks, the hyperpolarizing electrotonus shifted downward, while superexcitability became greater and subexcitability (double stimuli) decreased. Computer modeling showed that the most notable age-related interval changes in excitability parameters were Barrett-Barrett, H, and slow K(+) conductances. Understanding age-related changes in the excitability of sensory axons may provide a platform for understanding age-dependent sensory symptoms and developing age-specific channel-targeting therapies. PMID:26628247

  3. Rhythmic sensory stimulation improves fitness by conditioning the autonomic nervous system

    PubMed Central

    Frederiks, J.; Swenne, C.A.; Ghafoerkhan, A.; Lalmahomed, H.; Maan, A.C.; Schalij, M.J.; Bruschke, A.V.G.; van der Wall, E.E.

    2002-01-01

    Background Endurance training is known to alter the functioning of the autonomic nervous system, a major goal when pursuing fitness. Here, we test the hypothesis that the training-associated rhythmic sensations alone, hence without the usual accompanying physical exercise, accomplish this effect. Method We studied sixteen resting healthy male volunteers, age (mean±SD) 25.9±3.7 years. During one hour we applied, at marching pace (2 bursts per second), bipolar transcutaneous electrical sensory nerve stimulation to both feet. The stimulation intensity was controlled in such a way that discharges of sensory fibres in the tibial and fibular nerves were induced, while motor fibres were not excited. Heart rate, blood pressure, and baroreflex sensitivity were measured before and after stimulation. Results Baseline baroreflex sensitivity and systolic blood pressure were 8.7±4.5 ms·mmHg-1 and 117.5±6.4 mmHg, respectively. Directly after rhythmic sensory stimulation baroreflex sensitivity had increased to 10.0±4.1 ms·mmHg-1 (p<0.05). One day later, systolic blood pressure had lowered to 111.7±5.5 mmHg (p<0.01). Conclusions Rhythmic sensory stimulation entails autonomic adaptations that are comparable with those of exercise. This demonstration of sensory-induced autonomic adaptations without any muscular involvement may help to design alternative, low-effort fitness programmes for specific categories of sedentary, diseased or disabled persons. PMID:25696064

  4. Nerve growth factor induces sensitization of nociceptors without evidence for increased intraepidermal nerve fiber density.

    PubMed

    Hirth, Michael; Rukwied, Roman; Gromann, Alois; Turnquist, Brian; Weinkauf, Benjamin; Francke, Klaus; Albrecht, Philip; Rice, Frank; Hägglöf, Björn; Ringkamp, Matthias; Engelhardt, Maren; Schultz, Christian; Schmelz, Martin; Obreja, Otilia

    2013-11-01

    Nerve growth factor (NGF) is involved in the long-term sensitization of nociceptive processing linked to chronic pain. Functional and structural ("sprouting") changes can contribute. Thus, humans report long-lasting hyperalgesia to mechanical and electrical stimulation after intradermal NGF injection and NGF-induced sprouting has been reported to underlie cancer bone pain and visceral pain. Using a human-like animal model we investigated the relationship between the structure and function of unmyelinated porcine nociceptors 3 weeks after intradermal NGF treatment. Axonal and sensory characteristics were studied by in vivo single-fiber electrophysiology and immunohistochemistry. C fibers recorded extracellularly were classified based on mechanical response and activity-dependent slowing (ADS) of conduction velocity. Intraepidermal nerve fiber (IENF) densities were assessed by immunohistochemistry in pigs and in human volunteers using the same NGF model. NGF increased conduction velocity and reduced ADS and propagation failure in mechano-insensitive nociceptors. The proportion of mechano-sensitive C nociceptors within NGF-treated skin areas increased from 45.1% (control) to 71% and their median mechanical thresholds decreased from 40 to 20 mN. After NGF application, the mechanical receptive fields of nociceptors increased from 25 to 43 mm(2). At the structural level, however, IENF density was not increased by NGF. In conclusion, intradermal NGF induces long-lasting axonal and mechanical sensitization in porcine C nociceptors that corresponds to hyperalgesia observed in humans. Sensitization is not accompanied by increased IENF density, suggesting that NGF-induced hyperalgesia might not depend on changes in nerve fiber density but could be linked to the recruitment of previously silent nociceptors. PMID:23891896

  5. Cisplatin induced sensory neuropathy is prevented by vascular endothelial growth factor-A

    PubMed Central

    Vencappa, Samanta; Donaldson, Lucy F; Hulse, Richard P

    2015-01-01

    Increased patient survival is a mark of modern anti-cancer therapy success. Unfortunately treatment side-effects such as neurotoxicity are a major long term concern. Sensory neuropathy is one of the common toxicities that can arise during platinum based chemotherapy. In many cases the current poor understanding of the neurological degeneration and lack of suitable analgesia has led to high incidences of patient drop out of treatment. VEGF-A is a prominent neuroprotective agent thus it was hypothesised to prevent cisplatin induced neuropathy. Systemic cisplatin treatment (lasting 3 weeks biweekly) resulted in mechanical allodynia and heat hyperalgesia in mice when compared to vehicle control. PGP9.5 sensory nerve fibre innervation was reduced in the plantar skin in the cisplatin treated group versus vehicle control mice. The cisplatin induced sensory neurodegeneration was associated with increased cleaved caspase 3 expression as well as a reduction in Activating Transcription Factor 3 and pan VEGF-A expression in sensory neurons. VEGF-A165b expression was unaltered between vehicle and cisplatin treatment. rhVEGF-A165a and rhVEGF-A165b both prevented cisplatin induced sensory neurodegeneration. Cisplatin exposure blunts the regenerative properties of sensory neurons thus leading to sensory neuropathy. However, here it is identified that administration of VEGF-A isoform subtypes induce regeneration and prevent cell death and are therefore a possible adjunct therapy for chemotherapy induced neuropathy. PMID:26279748

  6. Sciatic nerve injury induces functional pro-nociceptive chemokine receptors in bladder-associated primary afferent neurons in the rat.

    PubMed

    Foster, R; Jung, J; Farooq, A; McClung, C; Ripsch, M S; Fitzgerald, M P; White, F A

    2011-06-01

    Visceral sensory afferents during disease or following injury often produce vague, diffuse body sensations, and pain referred to somatic targets. Alternatively, injury due to trauma or disease of somatic nerve targets can also lead to referred pain in visceral targets via a somatovisceral reflex. Both phenomenons are thought to be due to convergence of visceral and somatic afferents within the spinal cord. To investigate a potential peripheral influence for referred pain in visceral targets following somatic nerve injury, we examined whether a sciatic nerve injury known to produce hindpaw tactile hyperalgesia alters the frequency of micturition and the sensitivity of bladder-associated sensory neurons to pro-nociceptive chemokines. Adult female Sprague-Dawley rats received injections of cholera toxin B subunit conjugated to 555 into urinary bladder wall to retrogradely label visceral primary afferent neurons. After 7 days, the right sciatic nerve of these animals was subjected to a lysophosphatidylcholine (LPC)-induced focal demyelination injury. Pre- and post-injury tactile sensitivity in the hind paw and micturition frequency were assayed. Animals were allowed to survive for 14-28 days. Lumbosacral and lumbar dorsal root ganglia (DRG) ipsilateral to the nerve injury were acutely dissociated from sham and nerve injured animals. Bladder wall-associated sensory neurons identified via the retrograde marker were assayed for fluxes in intracellular calcium following administration of pro-nociceptive chemokines. The assayed chemokines included monocyte chemoattractant protein-1 (MCP1/CCL2) and stromal cell derived factor-1 alpha (SDF1/CXCL12). LPC nerve injured animals exhibited tactile hyperalgesia and increased micturition frequency for at least 28 days. Focal demyelination of the sciatic nerve also increased the number of injured L?L? and non-injured L?-S? bladder-associated sensory neurons that responded to MCP1 and SDF1 when compared with sensory neurons derived from uninjured naďve and sham-injured control animals. Taken together, these data suggest that some visceral hypersensitivity states may have a somatic origin. More importantly, nociceptive somatovisceral sensation may be mediated by upregulation of chemokine signaling in visceral sensory neurons. PMID:21458542

  7. Virtual Instrumentation for a Fiber-Optics-Based Artificial Nerve

    NASA Technical Reports Server (NTRS)

    Lyons, Donald R.; Kyaw, Thet Mon; Griffin, DeVon (Technical Monitor)

    2001-01-01

    A LabView-based computer interface for fiber-optic artificial nerves has been devised as a Masters thesis project. This project involves the use of outputs from wavelength multiplexed optical fiber sensors (artificial nerves), which are capable of producing dense optical data outputs for physical measurements. The potential advantages of using optical fiber sensors for sensory function restoration is the fact that well defined WDM-modulated signals can be transmitted to and from the sensing region allowing networked units to replace low-level nerve functions for persons desirous of "intelligent artificial limbs." Various FO sensors can be designed with high sensitivity and the ability to be interfaced with a wide range of devices including miniature shielded electrical conversion units. Our Virtual Instrument (VI) interface software package was developed using LabView's "Laboratory Virtual Instrument Engineering Workbench" package. The virtual instrument has been configured to arrange and encode the data to develop an intelligent response in the form of encoded digitized signal outputs. The architectural layout of our nervous system is such that different touch stimuli from different artificial fiber-optic nerve points correspond to gratings of a distinct resonant wavelength and physical location along the optical fiber. Thus, when an automated, tunable diode laser sends scans, the wavelength spectrum of the artificial nerve, it triggers responses that are encoded with different touch stimuli by way wavelength shifts in the reflected Bragg resonances. The reflected light is detected and a resulting analog signal is fed into ADC1 board and DAQ card. Finally, the software has been written such that the experimenter is able to set the response range during data acquisition.

  8. STRUCTURE OF THE MACULA UTRICULI WITH SPECIAL REFERENCE TO DIRECTIONAL INTERPLAY OF SENSORY RESPONSES AS REVEALED BY MORPHOLOGICAL POLARIZATION

    PubMed Central

    Flock, Ĺke

    1964-01-01

    The anatomy of the labyrinth and the structure of the macula utriculi of the teleost fish (burbot) Lota vulgaris was studied by dissection, phase contrast, and electron microscopy. The innervating nerve fibers end at the bottom of the sensory cells where two types of nerve endings are found, granulated and non-granulated. The ultrastructure and organization of the sensory hair bundles are described, and the finding that the receptor cells are morphologically polarized by the presence of an asymmetrically located kinocilium in the sensory hair bundle is discussed in terms of directional sensitivity. The pattern of orientation of the hair cells in the macula utriculi was determined, revealing a complicated morphological polarization of the sensory epithelium. The findings suggest that the interplay of sensory responses is intimately related to the directional sensitivity of the receptor cells as revealed by their morphological polarization. The problem of efferent innervation is discussed, and it is concluded that the positional information signaled by the nerve fibers innervating the vestibular organs comprises an intricate pattern of interacting afferent and efferent impulses PMID:14203389

  9. Hydrogen peroxide removes TRPM4 current desensitization conferring increased vulnerability to necrotic cell death.

    PubMed

    Simon, Felipe; Leiva-Salcedo, Elías; Armisén, Ricardo; Riveros, Ana; Cerda, Oscar; Varela, Diego; Eguiguren, Ana Luisa; Olivero, Pablo; Stutzin, Andrés

    2010-11-26

    Necrosis is associated with an increase in plasma membrane permeability, cell swelling, and loss of membrane integrity with subsequent release of cytoplasmic constituents. Severe redox imbalance by overproduction of reactive oxygen species is one of the main causes of necrosis. Here we demonstrate that H(2)O(2) induces a sustained activity of TRPM4, a Ca(2+)-activated, Ca(2+)-impermeant nonselective cation channel resulting in an increased vulnerability to cell death. In HEK 293 cells overexpressing TRPM4, H(2)O(2) was found to eliminate in a dose-dependent manner TRPM4 desensitization. Site-directed mutagenesis experiments revealed that the Cys(1093) residue is crucial for the H(2)O(2)-mediated loss of desensitization. In HeLa cells, which endogenously express TRPM4, H(2)O(2) elicited necrosis as well as apoptosis. H(2)O(2)-mediated necrosis but not apoptosis was abolished by replacement of external Na(+) ions with sucrose or the non-permeant cation N-methyl-d-glucamine and by knocking down TRPM4 with a shRNA directed against TRPM4. Conversely, transient overexpression of TRPM4 in HeLa cells in which TRPM4 was previously silenced re-established vulnerability to H(2)O(2)-induced necrotic cell death. In addition, HeLa cells exposed to H(2)O(2) displayed an irreversible loss of membrane potential, which was prevented by TRPM4 knockdown. PMID:20884614

  10. Hydrogen Peroxide Removes TRPM4 Current Desensitization Conferring Increased Vulnerability to Necrotic Cell Death*

    PubMed Central

    Simon, Felipe; Leiva-Salcedo, Elías; Armisén, Ricardo; Riveros, Ana; Cerda, Oscar; Varela, Diego; Eguiguren, Ana Luisa; Olivero, Pablo; Stutzin, Andrés

    2010-01-01

    Necrosis is associated with an increase in plasma membrane permeability, cell swelling, and loss of membrane integrity with subsequent release of cytoplasmic constituents. Severe redox imbalance by overproduction of reactive oxygen species is one of the main causes of necrosis. Here we demonstrate that H2O2 induces a sustained activity of TRPM4, a Ca2+-activated, Ca2+-impermeant nonselective cation channel resulting in an increased vulnerability to cell death. In HEK 293 cells overexpressing TRPM4, H2O2 was found to eliminate in a dose-dependent manner TRPM4 desensitization. Site-directed mutagenesis experiments revealed that the Cys1093 residue is crucial for the H2O2-mediated loss of desensitization. In HeLa cells, which endogenously express TRPM4, H2O2 elicited necrosis as well as apoptosis. H2O2-mediated necrosis but not apoptosis was abolished by replacement of external Na+ ions with sucrose or the non-permeant cation N-methyl-d-glucamine and by knocking down TRPM4 with a shRNA directed against TRPM4. Conversely, transient overexpression of TRPM4 in HeLa cells in which TRPM4 was previously silenced re-established vulnerability to H2O2-induced necrotic cell death. In addition, HeLa cells exposed to H2O2 displayed an irreversible loss of membrane potential, which was prevented by TRPM4 knockdown. PMID:20884614

  11. Effectiveness of cognitive behavioral therapy integrated with systematic desensitization, cognitive behavioral therapy combined with eye movement desensitization and reprocessing therapy, and cognitive behavioral therapy combined with virtual reality exposure therapy methods in the treatment of flight anxiety: a randomized trial

    PubMed Central

    Triscari, Maria Teresa; Faraci, Palmira; Catalisano, Dario; D’Angelo, Valerio; Urso, Viviana

    2015-01-01

    The purpose of the research was to compare the effectiveness of the following treatment methods for fear of flying: cognitive behavioral therapy (CBT) integrated with systematic desensitization, CBT combined with eye movement desensitization and reprocessing therapy, and CBT combined with virtual reality exposure therapy. Overall, our findings have proven the efficacy of all interventions in reducing fear of flying in a pre- to post-treatment comparison. All groups showed a decrease in flight anxiety, suggesting the efficiency of all three treatments in reducing self-report measures of fear of flying. In particular, our results indicated significant improvements for the treated patients using all the treatment programs, as shown not only by test scores but also by participation in the post-treatment flight. Nevertheless, outcome measures maintained a significant effect at a 1-year follow-up. In conclusion, combining CBT with both the application of eye movement desensitization and reprocessing treatment and the virtual stimuli used to expose patients with aerophobia seemed as efficient as traditional cognitive behavioral treatments integrated with systematic desensitization. PMID:26504391

  12. Sensory adaptation for timing perception.

    PubMed

    Roseboom, Warrick; Linares, Daniel; Nishida, Shin'ya

    2015-04-22

    Recent sensory experience modifies subjective timing perception. For example, when visual events repeatedly lead auditory events, such as when the sound and video tracks of a movie are out of sync, subsequent vision-leads-audio presentations are reported as more simultaneous. This phenomenon could provide insights into the fundamental problem of how timing is represented in the brain, but the underlying mechanisms are poorly understood. Here, we show that the effect of recent experience on timing perception is not just subjective; recent sensory experience also modifies relative timing discrimination. This result indicates that recent sensory history alters the encoding of relative timing in sensory areas, excluding explanations of the subjective phenomenon based only on decision-level changes. The pattern of changes in timing discrimination suggests the existence of two sensory components, similar to those previously reported for visual spatial attributes: a lateral shift in the nonlinear transducer that maps relative timing into perceptual relative timing and an increase in transducer slope around the exposed timing. The existence of these components would suggest that previous explanations of how recent experience may change the sensory encoding of timing, such as changes in sensory latencies or simple implementations of neural population codes, cannot account for the effect of sensory adaptation on timing perception. PMID:25788590

  13. True navigation in migrating gulls requires intact olfactory nerves.

    PubMed

    Wikelski, Martin; Arriero, Elena; Gagliardo, Anna; Holland, Richard A; Huttunen, Markku J; Juvaste, Risto; Mueller, Inge; Tertitski, Grigori; Thorup, Kasper; Wild, Martin; Alanko, Markku; Bairlein, Franz; Cherenkov, Alexander; Cameron, Alison; Flatz, Reinhard; Hannila, Juhani; Hüppop, Ommo; Kangasniemi, Markku; Kranstauber, Bart; Penttinen, Maija-Liisa; Safi, Kamran; Semashko, Vladimir; Schmid, Heidi; Wistbacka, Ralf

    2015-01-01

    During migratory journeys, birds may become displaced from their normal migratory route. Experimental evidence has shown that adult birds can correct for such displacements and return to their goal. However, the nature of the cues used by migratory birds to perform long distance navigation is still debated. In this experiment we subjected adult lesser black-backed gulls migrating from their Finnish/Russian breeding grounds (from >60°N) to Africa (to?sensory manipulation, to determine the sensory systems required for navigation. We translocated birds westward (1080?km) or eastward (885?km) to simulate natural navigational challenges. When translocated westwards and outside their migratory corridor birds with olfactory nerve section kept a clear directional preference (southerly) but were unable to compensate for the displacement, while intact birds and gulls with the ophthalmic branch of the trigeminal nerve sectioned oriented towards their population-specific migratory corridor. Thus, air-borne olfactory information seems to be important for migrating gulls to navigate successfully in some circumstances. PMID:26597351

  14. True navigation in migrating gulls requires intact olfactory nerves

    PubMed Central

    Wikelski, Martin; Arriero, Elena; Gagliardo, Anna; Holland, Richard A.; Huttunen, Markku J.; Juvaste, Risto; Mueller, Inge; Tertitski, Grigori; Thorup, Kasper; Wild, Martin; Alanko, Markku; Bairlein, Franz; Cherenkov, Alexander; Cameron, Alison; Flatz, Reinhard; Hannila, Juhani; Hüppop, Ommo; Kangasniemi, Markku; Kranstauber, Bart; Penttinen, Maija-Liisa; Safi, Kamran; Semashko, Vladimir; Schmid, Heidi; Wistbacka, Ralf

    2015-01-01

    During migratory journeys, birds may become displaced from their normal migratory route. Experimental evidence has shown that adult birds can correct for such displacements and return to their goal. However, the nature of the cues used by migratory birds to perform long distance navigation is still debated. In this experiment we subjected adult lesser black-backed gulls migrating from their Finnish/Russian breeding grounds (from >60°N) to Africa (to?sensory manipulation, to determine the sensory systems required for navigation. We translocated birds westward (1080?km) or eastward (885?km) to simulate natural navigational challenges. When translocated westwards and outside their migratory corridor birds with olfactory nerve section kept a clear directional preference (southerly) but were unable to compensate for the displacement, while intact birds and gulls with the ophthalmic branch of the trigeminal nerve sectioned oriented towards their population-specific migratory corridor. Thus, air-borne olfactory information seems to be important for migrating gulls to navigate successfully in some circumstances. PMID:26597351

  15. Mass Spectrometry Imaging and GC-MS Profiling of the Mammalian Peripheral Sensory-Motor Circuit

    NASA Astrophysics Data System (ADS)

    Rubakhin, Stanislav S.; Ulanov, Alexander; Sweedler, Jonathan V.

    2015-06-01

    Matrix-assisted laser desorption/ionization (MALDI) mass spectrometry imaging (MSI) has evolved to become an effective discovery tool in science and clinical diagnostics. Here, chemical imaging approaches are applied to well-defined regions of the mammalian peripheral sensory-motor system, including the dorsal root ganglia (DRG) and adjacent nerves. By combining several MSI approaches, analyte coverage is increased and 195 distinct molecular features are observed. Principal component analysis suggests three chemically different regions within the sensory-motor system, with the DRG and adjacent nerve regions being the most distinct. Investigation of these regions using gas chromatography-mass spectrometry corroborate these findings and reveal important metabolic markers related to the observed differences. The heterogeneity of the structurally, physiologically, and functionally connected regions demonstrates the intricate chemical and spatial regulation of their chemical composition.

  16. Evaluation of femoral nerve blockade following inguinal paravascular block of Winnie: are there still lessons to be learnt?

    PubMed

    Jochum, D; O'Neill, T; Jabbour, H; Diarra, P D; Cuignet-Pourel, E; Bouaziz, H

    2005-10-01

    Lower limb peripheral nerve blocks are used to provide surgical anaesthesia or postoperative analgesia. Anatomical texts imply that femoral and saphenous nerve blocks be evaluated by sensory testing of the skin overlying the anterior aspect of the thigh, and the medial aspect of the foot, respectively. We have mapped the distribution of anaesthesia in 25 adults following femoral nerve blockade, performed using the inguinal paravascular technique of Winnie. There was substantial interindividual variation in the area of anaesthesia. Only the skin overlying the middle third of the medial thigh was consistently blocked in 100% of patients. The distribution of anaesthesia conformed to anatomical text descriptions in 24% of cases. We conclude that demonstration of complete quadriceps paralysis confirms femoral nerve blockade. Failing that, sensory evaluation of a femoral nerve block should involve testing the skin of the middle third of the medial aspect of the thigh. The skin overlying the anteromedial aspect of the middle third of the leg should be evaluated for saphenous nerve block. PMID:16179041

  17. Periosteum Metabolism and Nerve Fiber Positioning Depend on Interactions between Osteoblasts and Peripheral Innervation in Rat Mandible

    PubMed Central

    Mauprivez, Cédric; Bataille, Caroline; Baroukh, Brigitte; Llorens, Annie; Lesieur, Julie; Marie, Pierre J.; Saffar, Jean-Louis; Biosse Duplan, Martin; Cherruau, Marc

    2015-01-01

    The sympathetic nervous system controls bone remodeling by regulating bone formation and resorption. How nerves and bone cells influence each other remains elusive. Here we modulated the content or activity of the neuropeptide Vasoactive Intestinal Peptide to investigate nerve-bone cell interplays in the mandible periosteum by assessing factors involved in nerve and bone behaviors. Young adult rats were chemically sympathectomized or treated with Vasoactive Intestinal Peptide or Vasoactive Intestinal Peptide10-28, a receptor antagonist. Sympathectomy depleted the osteogenic layer of the periosteum in neurotrophic proNerve Growth Factor and neurorepulsive semaphorin3a; sensory Calcitonin-Gene Related Peptide-positive fibers invaded this layer physiologically devoid of sensory fibers. In the periosteum non-osteogenic layer, sympathectomy activated mast cells to release mature Nerve Growth Factor while Calcitonin-Gene Related Peptide-positive fibers increased. Vasoactive Intestinal Peptide treatment reversed sympathectomy effects. Treating intact animals with Vasoactive Intestinal Peptide increased proNerve Growth Factor expression and stabilized mast cells. Vasoactive Intestinal Peptide10-28 treatment mimicked sympathectomy effects. Our data suggest that sympathetic Vasoactive Intestinal Peptide modulate the interactions between nervous fibers and bone cells by tuning expressions by osteogenic cells of factors responsible for mandible periosteum maintenance while osteogenic cells keep nervous fibers at a distance from the bone surface. PMID:26509533

  18. Isolated Ocular Motor Nerve Palsies.

    PubMed

    Kung, Nathan H; Van Stavern, Gregory P

    2015-10-01

    An isolated ocular motor nerve palsy is defined as dysfunction of a single ocular motor nerve (oculomotor, trochlear, or abducens) with no associated or localizing neurologic signs or symptoms. When occurring in patients aged 50 or older, the most common cause is microvascular ischemia, but serious etiologies such as aneurysm, malignancy, and giant cell arteritis should always be considered. In this article, the authors review the clinical approach, anatomy, and differential diagnosis of each isolated ocular motor nerve palsy and discuss the clinical characteristics, pathophysiology, and treatment of microvascular ischemia. PMID:26444399

  19. Synaptic organization of sensory and motor neurones innervating triceps brachii muscles in the bullfrog

    PubMed Central

    Frank, Eric; Westerfield, Monte

    1982-01-01

    1. The anatomy and physiology of sensory-motor pathways were studied in the brachial spinal cord of adult bullfrogs to characterize the properties and specificity of these connexions. 2. Motoneurones innervating a given forelimb muscle are located in discrete and reproducible regions of the lateral motor column. Yet only a fraction of the motoneurones in a particular region innervates any one muscle. 3. The central projections of sensory afferent axons from the triceps muscles extend throughout the rostro-caudal length of the brachial spinal cord. Within this region these projections terminate in an area containing many motoneuronal dendrites. 4. Within the triceps motor pool sensory neurones from the triceps muscles produce monosynaptic potentials only in triceps motoneurones even though these motoneurones are mingled with motoneurones innervating other muscles. 5. Motoneurones innervating each of the three heads of the triceps muscles, medial, internal and external, receive monosynaptic input from their own, homonymous muscle head. Sensory fibres from the medial head also innervate 98% of the heteronymous motoneurones projecting to the internal or external heads, and nearly 90% of the medial triceps motoneurones are innervated by sensory axons from the other two heads. 6. Similarly, other brachial motoneurones receive monosynaptic input from sensory axons in their own muscle nerves. However, most of the synaptic potentials evoked in triceps motoneurones by stimulation of muscle nerves other than triceps are of longer latency and probably involve polysynaptic pathways. 7. Thus, the pattern of synaptic connexions between muscle sensory afferents and motoneurones in the frog's spinal cord is specific. Furthermore, comparison with homologous pathways in the cat's spinal cord suggests that the strength and pattern of these connexions are similar. ImagesPlate 2Plate 3Plate 4Plate 1 PMID:6980276

  20. The Efficacy of Eye Movement Desensitization and Reprocessing Therapy Technique in the Treatment of Test Anxiety of College Students.

    ERIC Educational Resources Information Center

    Enright, Matthew; Baldo, Tracy D.; Wykes, Scott D.

    2000-01-01

    Explores the efficacy of eye movement desensitization and reprocessing (EMDR) in the treatment of test anxiety. Thirty-five college students with test anxiety were assigned to either a treatment or delayed treatment control group. EMDR was shown to be effective in reducing overall test anxiety as well as "emotionality" and "worry" components of…

  1. Characterization of the functional heterologous desensitization of hypothalamic 5-HT1A receptors after 5-HT2A receptor activation

    E-print Network

    Zhang, Yahong; D'Souza, Deborah N.; Raap, Dan?? K.; Garcia, Francisca; Battaglia, George; Muma, Nancy A.; Van de Kar, Louis D.

    2001-10-15

    Desensitization of 5-HT1A receptors could be involved in the long-term therapeutic effect of anxiolytic and antidepressant drugs. Pretreatment of rats with the 5-HT2A/2C agonist DOI induces an attenuation of hypothalamic 5-HT1Areceptor–Gz...

  2. A Systematic Desensitization Paradigm to Treat Hypersensitivity to Auditory Stimuli in Children with Autism in Family Contexts

    ERIC Educational Resources Information Center

    Koegel, Robert L.; Openden, Daniel; Koegel, Lynn Kern

    2004-01-01

    Many children with autism display reactions to auditory stimuli that seem as if the stimuli were painful or otherwise extremely aversive. This article describes, within the contexts of three experimental designs, how procedures of systematic desensitization can be used to treat hypersensitivity to auditory stimuli in three young children with…

  3. Nicotine-induced Up-regulation and Desensitization of 4 2 Neuronal Nicotinic Receptors Depend on Subunit Ratio*

    E-print Network

    Lasalde Dominicc, Jose A. - Department of Biology, Universidad de Puerto Rico

    acetylcholine receptors (nAChRs)1 belong to a superfamily of ligand-gated ion channels (e.g. -aminobu- tyricNicotine-induced Up-regulation and Desensitization of 4 2 Neuronal Nicotinic Receptors Depend exposure has been hypothesized to trigger the up-regulation of the 4 2 neuronal nicotinic acetylcholine

  4. It's not “either/or”: activation and desensitization of nicotinic acetylcholine receptors both contribute to behaviors related to nicotine addiction and mood

    PubMed Central

    Picciotto, Marina R.; Addy, Nii A.; Mineur, Yann S.; Brunzell, Darlene H.

    2008-01-01

    Nicotine can both activate and desensitize/inactivate nicotinic acetylcholine receptors (nAChRs). An ongoing controversy in the field is to what extent the behavioral effects of nicotine result from activation of nAChRs, and to what extent receptor desensitization is involved in these behavioral processes. Recent electrophysiological studies have shown that both nAChR activation and desensitization contribute to the effects of nicotine in the brain, and these experiments have provided cellular mechanisms that could underlie the contribution of both of these processes to nicotine-mediated behaviors. For instance, desensitization of nAChRs may contribute to the salience of environmental cues associated with smoking behavior and activation and desensitization of nAChRs may contribute to both primary and conditioned drug reward. Similarly, studies of the antidepressant-like effects of nicotinic agents have revealed a balance between activation and desensitization of nAChRs. This review will examine the evidence for the contribution of these two very different consequences of nicotine administration to behaviors related to nicotine addiction, including processes related to drug reinforcement and affective modulation. We conclude that there are effects of nAChR activation and desensitization on drug reinforcement and affective behavior, and that both processes are important in the behavioral consequences of nicotine in tobacco smoking. PMID:18242816

  5. Contribution of nitric oxide-dependent guanylate cyclase and reactive oxygen species signaling pathways to desensitization of ?-opioid receptors in the rat locus coeruleus.

    PubMed

    Pablos, Patricia; Mendiguren, Aitziber; Pineda, Joseba

    2015-12-01

    Nitric oxide (NO) is involved in desensitization of ?-opioid receptors (MOR). We used extracellular recordings in vitro to unmask the NO-dependent pathways involved in MOR desensitization in the rat locus coeruleus (LC). Perfusion with ME (3 and 10 ?M) concentration-dependently reduced subsequent ME effect, indicative of MOR desensitization. ME (3 ?M)-induced desensitization was enhanced by a NO donor (DEA/NO 100 ?M), two soluble guanylate cyclase (sGC) activators (A 350619 30 ?M and BAY 418543 1 ?M) or a cGMP-dependent protein kinase (PKG) activator (8-pCPT-cGMP 30 ?M). DEA/NO-induced enhancement was blocked by the sGC inhibitor NS 2028 (10 ?M). A 350619 effect was also blocked by NS 2028, but not by the antioxidant Trolox. ME (10 ?M)-induced desensitization was blocked by the neuronal NO synthase inhibitor 7-NI (100 ?M) and restored by the PKG activator 8-Br-cGMP (100-300 ?M). Paradoxically, ME (10 ?M)-induced desensitization was not modified by sGC inhibitors (NS 2028 and ODQ), PKG inhibitors (H8 and Rp-8-Br-PET-cGMP) or antioxidant agents (Trolox, U-74389G and melatonin), but it was attenuated by a combination of NS 2028 and Trolox. In conclusion, MOR desensitization in the LC may be mediated or regulated by NO through sGC and reactive oxygen species signaling pathways. PMID:26254861

  6. Neurogenin 1 Null Mutant Ears Develop Fewer, Morphologically Normal Hair Cells in Smaller Sensory Epithelia Devoid of Innervation

    PubMed Central

    Ma, Qiufu; Anderson, David J.

    2000-01-01

    The proneuronal gene neurogenin 1 (ngn1) is essential for development of the inner-ear sensory neurons that are completely absent in ngn1 null mutants. Neither afferent, efferent, nor autonomic nerve fibers were detected in the ears of ngn1 null mutants. We suggest that efferent and autonomic fibers are lost secondarily to the absence of afferents. In this article we show that ngn1 null mutants develop smaller sensory epithelia with morphologically normal hair cells. In particular, the saccule is reduced dramatically and forms only a small recess with few hair cells along a duct connecting the utricle with the cochlea. Hair cells of newborn ngn1 null mutants show no structural abnormalities, suggesting that embryonic development of hair cells is independent of innervation. However, the less regular pattern of dispersal within sensory epithelia may be caused by some effects of afferents or to the stunted growth of the sensory epithelia. Tracing of facial and stato-acoustic nerves in control and ngn1 null mutants showed that only the distal, epibranchial, placode-derived sensory neurons of the geniculate ganglion exist in mutants. Tracing further showed that these geniculate ganglion neurons project exclusively to the solitary tract. In addition to the normal complement of facial branchial and visceral motoneurons, ngn1 null mutants have some trigeminal motoneurons and contralateral inner-ear efferents projecting, at least temporarily, through the facial nerve. These data suggest that some neurons in the brainstem (e.g., inner-ear efferents, trigeminal motoneurons) require afferents to grow along and redirect to ectopic cranial nerve roots in the absence of their corresponding sensory roots. PMID:11545141

  7. Matrix metalloproteinase-8 is involved in dermal nerve growth: implications for possible application to pruritus from in vitro models.

    PubMed

    Tominaga, Mitsutoshi; Tengara, Suhandy; Kamo, Atsuko; Ogawa, Hideoki; Takamori, Kenji

    2011-10-01

    Cutaneous nerve density is related to abnormal itch perception in dermatoses, such as atopic dermatitis and xerosis. However, the mechanisms underlying the elongation of dermal nerve fibers within the interstitial collagen (CoL) matrix are poorly understood. In this study, a culture system of rat dorsal root ganglion neurons consisting of type I CoL and a Boyden chamber containing a nerve growth factor (NGF) concentration gradient was used. Nerve fibers penetrating into type I CoL gel were observed in the presence of the NGF concentration gradient. Levels of matrix metalloproteinase-8 (MMP-8) mRNA and protein were increased in the cultured neurons and the conditioned medium, respectively. The nerve fiber penetration was dose dependently inhibited by MMP-8 blockers. Moreover, MMP-8 immunoreactivity was partially localized at growth cones in NGF-responsive nerve fibers. Semaphorin 3A stimulation also showed the opposite effects on these NGF-dependent events. Intriguingly, MMP-8 expression was upregulated by type I and III CoLs, which are substrates for this enzyme. These results suggested that MMP-8 is involved in sensory nerve growth within the interstitial CoL matrix through modulation by the axonal guidance molecules and/or extracellular matrix components. These findings provide insight into the development of pruritus involving skin nerve density. PMID:21697883

  8. The mechanism of action of aniracetam at synaptic alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors: indirect and direct effects on desensitization.

    PubMed

    Lawrence, J Josh; Brenowitz, Stephan; Trussell, Laurence O

    2003-08-01

    The mechanism of action of aniracetam on alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors was examined in outside-out patches and at glutamatergic synapses in neurons of the chick cochlear nucleus. A combination of rapid-flow analysis, using glutamate as an agonist, and kinetic modeling indicated that aniracetam slows both the rate of channel closing, and the microscopic rates of desensitization, even for partially liganded receptors. Little effect was observed on the rate of recovery from desensitization or on the response to the weakly desensitizing agonist kainate. Aniracetam's effects on receptor deactivation saturated at lower concentrations than its effects on desensitization, suggesting that cooperativity between homologous binding sites was required to regulate desensitization. Analysis of responses to paired pulses of agonist also indicated that AMPA receptors must desensitize partially even after agonist exposures too brief to permit rebinding. In the presence of aniracetam, evoked excitatory synaptic currents (EPSCs) and miniature EPSCs in low quantal-content conditions had decay times similar to the time course of receptor deactivation. Under these conditions, the time course of both transmitter release and clearance must be <1 to 2 ms. However, in high quantal-content conditions, the evoked EPSC in aniracetam decayed with a time course intermediate between deactivation and desensitization, suggesting that the time course of transmitter clearance is prolonged because of pooling of transmitter in the synaptic cleft. Moreover, by comparing the amounts of paired-pulse synaptic depression and patch desensitization prevented by aniracetam, we conclude that significant desensitization occurs in response to rebinding of transmitter to the AMPA receptors. PMID:12869631

  9. Near-infrared signals associated with electrical stimulation of peripheral nerves

    NASA Astrophysics Data System (ADS)

    Fantini, Sergio; Chen, Debbie K.; Martin, Jeffrey M.; Sassaroli, Angelo; Bergethon, Peter R.

    2009-02-01

    We report our studies on the optical signals measured non-invasively on electrically stimulated peripheral nerves. The stimulation consists of the delivery of 0.1 ms current pulses, below the threshold for triggering any visible motion, to a peripheral nerve in human subjects (we have studied the sural nerve and the median nerve). In response to electrical stimulation, we observe an optical signal that peaks at about 100 ms post-stimulus, on a much longer time scale than the few milliseconds duration of the electrical response, or sensory nerve action potential (SNAP). While the 100 ms optical signal we measured is not a direct optical signature of neural activation, it is nevertheless indicative of a mediated response to neural activation. We argue that this may provide information useful for understanding the origin of the fast optical signal (also on a 100 ms time scale) that has been measured non-invasively in the brain in response to cerebral activation. Furthermore, the optical response to peripheral nerve activation may be developed into a diagnostic tool for peripheral neuropathies, as suggested by the delayed optical signals (average peak time: 230 ms) measured in patients with diabetic neuropathy with respect to normal subjects (average peak time: 160 ms).

  10. A histological analysis of human median and ulnar nerves following implantation of Utah slanted electrode arrays.

    PubMed

    Christensen, Michael B; Wark, Heather A C; Hutchinson, Douglas T

    2016-01-01

    For decades, epineurial electrodes have been used in clinical therapies involving the stimulation of peripheral nerves. However, next generation peripheral nerve interfaces for applications such as neuroprosthetics would benefit from an increased ability to selectively stimulate and record from nerve tissue. This increased selectivity may require the use of more invasive devices, such as the Utah Slanted Electrode Array (USEA). Previous research with USEAs has described the histological response to the implantation of these devices in cats and rats; however, no such data has been presented in humans. Therefore, we describe here the degree of penetration and foreign body reaction to USEAs after a four-week implantation period in human median and ulnar nerves. We found that current array designs penetrate a relatively small percentage of the available endoneurial tissue in these large nerves. When electrode tips were located within the endoneurial tissue, labels for axons and myelin were found in close proximity to electrodes. Consistent with other reports, we found activated macrophages attached to explanted devices, as well as within the tissue surrounding the implantation site. Despite this inflammatory response, devices were able to successfully record single- or multi-unit action potentials and elicit sensory percepts. However, modifying device design to allow for greater nerve penetration, as well as mitigating the inflammatory response to such devices, would likely increase device performance and should be investigated in future research. PMID:26606449

  11. Nerve maintenance and regeneration in the damaged cochlea.

    PubMed

    Shibata, Seiji B; Budenz, Cameron L; Bowling, Sara A; Pfingst, Bryan E; Raphael, Yehoash

    2011-11-01

    Following the onset of sensorineural hearing loss, degeneration of mechanosensitive hair cells and spiral ganglion cells (SGCs) in humans and animals occurs to variable degrees, with a trend for greater neural degeneration with greater duration of deafness. Emergence of the cochlear implant prosthesis has provided much needed aid to many hearing impaired patients and has become a well-recognized therapy worldwide. However, ongoing peripheral nerve fiber regression and subsequent degeneration of SGC bodies can reduce the neural targets of cochlear implant stimulation and diminish its function. There is increasing interest in bio-engineering approaches that aim to enhance cochlear implant efficacy by preventing SGC body degeneration and/or regenerating peripheral nerve fibers into the deaf sensory epithelium. We review the advancements in maintaining and regenerating nerves in damaged animal cochleae, with an emphasis on the therapeutic capacity of neurotrophic factors delivered to the inner ear after an insult. Additionally, we summarize the histological process of neuronal degeneration in the inner ear and describe different animal models that have been employed to study this mechanism. Research on enhancing the biological infrastructure of the deafened cochlea in order to improve cochlear implant efficacy is of immediate clinical importance. PMID:21596129

  12. Differential activation of nerve fibers with magnetic stimulation in humans

    PubMed Central

    Tuday, Eric C; Olree, Kenneth S; Horch, Kenneth W

    2006-01-01

    Background Earlier observations in our lab had indicated that large, time-varying magnetic fields could elicit action potentials that travel in only one direction in at least some of the myelinated axons in peripheral nerves. The objective of this study was to collect quantitative evidence for magnetically induced unidirectional action potentials in peripheral nerves of human subjects. A magnetic coil was maneuvered to a location on the upper arm where physical effects consistent with the creation of unidirectional action potentials were observed. Electromyographic (EMG) and somatosensory evoked potential (SEP) recordings were then made from a total of 20 subjects during stimulation with the magnetic coil. Results The relative amplitudes of the EMG and SEP signals changed oppositely when the current direction in the magnetic coil was reversed. This effect was consistent with current direction in the coil relative to the arm for all subjects. Conclusion A differential evocation of motor and sensory fibers was demonstrated and indicates that it may be possible to induce unidirectional action potentials in myelinated peripheral nerve fibers with magnetic stimulation. PMID:16863593

  13. Effect of pretreatment with calcium-containing desensitizer on the dentine bonding of mild self-etch adhesives.

    PubMed

    Pei, Dandan; Liu, Siying; Huang, Cui; Du, Xijin; Yang, Hongye; Wang, Yake; Deng, Donglai

    2013-06-01

    Desensitizing agents are frequently applied to sensitive teeth and may affect subsequent resin bonding. The current study aimed to evaluate the bonding performance of two self-etch adhesives containing functional monomers to dentine pretreated with three new calcium-containing desensitizers. No desensitizer was applied in the control group. Groups 1, 2, and 3 were treated with an arginine-calcium carbonate-containing polishing paste, a casein phosphopeptide-amorphous calcium phosphate (CPP-ACP)-containing paste, and an experimental hydroxyapatite paste, respectively. G-Bond and Clearfil S(3) Bond were used for bonding after desensitizer treatments. The microtensile bond strength (?TBS) was tested (n = 20 beams per group) and failure mode distribution was analyzed. Scanning electron microscopy was used to observe the occlusion of dentinal tubules. The mean (±SD) ?TBS values, expressed in MPa, of groups 1, 2, and 3 and the control group were, respectively, 30.81 (7.79), 44.41 (8.02), 31.49 (6.13), and 41.40 (8.67) for G-Bond and 39.63 (9.59), 32.55 (7.86), 37.50 (8.60), 27.90 (6.52) for S3 Bond. Most failures were recorded as adhesive failure (69.375%), instead of cohesive failure or mixed failure. The dentinal tubules were seldom plugged in group 2, but were mostly occluded in groups 1 and 3. Two-way anova indicated that desensitizer application in association with a compatible adhesive system should be used when endeavoring to control hypersensitivity without adverse interference in bonding. PMID:23659244

  14. Cross-desensitization of CCR1, but not CCR2, following activation of the formyl peptide receptor FPR1.

    PubMed

    Bednar, Filip; Song, Changcheng; Bardi, Giuseppe; Cornwell, William; Rogers, Thomas J

    2014-06-01

    The cross-regulation of G protein-coupled receptors (GPCRs) plays an important role in the immune response. Studies from several laboratories have suggested that a hierarchy of sensitivities to cross-desensitization exists for the chemoattractant GPCRs. We carried out experiments to study the capacity of the formyl peptide receptor-1 (FPR1) to desensitize chemokine receptors CCR1 and CCR2. Our results show that activation of FPR1 resulted in the desensitization and partial internalization of CCR1, but not CCR2, in both primary human monocytes and HEK293 cells coexpressing CCR1, CCR2, and FPR1 (HR1R2F cells). The desensitization of CCR1 by FPR1 stimulation was not due to the simple depletion of the Ca(2+) stores, but was dependent on activation of protein kinase C. Furthermore, we found that the cross-desensitization of CCR1 by FPR1 was associated with CCR1 phosphorylation and moderate reduction of CCR1 cell-surface expression. In contrast, CCR2 was not phosphorylated or internalized after FPR1 activation. Additional studies showed that optimal cross talk between FPR1 and CCR1 was dependent on the functional activity of protein kinase C?. These results provide a mechanistic basis for the capacity of certain GPCR ligands to exert rapid and selective cross-inactivation of other chemoattractant receptors, and suggest that FPR1 is able to exert "traffic control" in the migration of inflammatory cells by rapidly inhibiting the cell responses to potentially "low-priority" chemoattractants such as CCR1 agonists without inhibiting the response to "higher priority" CCR2 chemoattractants. PMID:24778447

  15. Ion Channels in Nerve Membranes

    ERIC Educational Resources Information Center

    Ehrenstein, Gerald

    1976-01-01

    Discusses research that indicates that nerve membranes, which play a key role in the conduction of impulses, are traversed by protein channels with ion pathways opened and closed by the membrane electric field. (Author/MLH)

  16. Optogenetic control of nerve growth

    E-print Network

    Park, Seongjun

    Due to the limited regenerative ability of neural tissue, a diverse set of biochemical and biophysical cues for increasing nerve growth has been investigated, including neurotrophic factors, topography, and electrical ...

  17. Nociceptive sensory neurons drive interleukin-23-mediated psoriasiform skin inflammation.

    PubMed

    Riol-Blanco, Lorena; Ordovas-Montanes, Jose; Perro, Mario; Naval, Elena; Thiriot, Aude; Alvarez, David; Paust, Silke; Wood, John N; von Andrian, Ulrich H

    2014-06-01

    The skin has a dual function as a barrier and a sensory interface between the body and the environment. To protect against invading pathogens, the skin harbours specialized immune cells, including dermal dendritic cells (DDCs) and interleukin (IL)-17-producing ?? T (??T17) cells, the aberrant activation of which by IL-23 can provoke psoriasis-like inflammation. The skin is also innervated by a meshwork of peripheral nerves consisting of relatively sparse autonomic and abundant sensory fibres. Interactions between the autonomic nervous system and immune cells in lymphoid organs are known to contribute to systemic immunity, but how peripheral nerves regulate cutaneous immune responses remains unclear. We exposed the skin of mice to imiquimod, which induces IL-23-dependent psoriasis-like inflammation. Here we show that a subset of sensory neurons expressing the ion channels TRPV1 and Nav1.8 is essential to drive this inflammatory response. Imaging of intact skin revealed that a large fraction of DDCs, the principal source of IL-23, is in close contact with these nociceptors. Upon selective pharmacological or genetic ablation of nociceptors, DDCs failed to produce IL-23 in imiquimod-exposed skin. Consequently, the local production of IL-23-dependent inflammatory cytokines by dermal ??T17 cells and the subsequent recruitment of inflammatory cells to the skin were markedly reduced. Intradermal injection of IL-23 bypassed the requirement for nociceptor communication with DDCs and restored the inflammatory response. These findings indicate that TRPV1(+)Nav1.8(+) nociceptors, by interacting with DDCs, regulate the IL-23/IL-17 pathway and control cutaneous immune responses. PMID:24759321

  18. Nociceptive Sensory Neurons Drive Interleukin-23 Mediated Psoriasiform Skin Inflammation

    PubMed Central

    Riol-Blanco, Lorena; Ordovas-Montanes, Jose; Perro, Mario; Naval, Elena; Thiriot, Aude; Alvarez, David; Wood, John N.; von Andrian, Ulrich H.

    2014-01-01

    The skin has a dual function as a barrier and a sensory interface between the body and the environment. To protect against invading pathogens, the skin harbors specialized immune cells, including dermal dendritic cells (DDCs) and interleukin (IL)-17 producing ?? T cells (??T17), whose aberrant activation by IL-23 can provoke psoriasis-like inflammation1–4. The skin is also innervated by a meshwork of peripheral nerves consisting of relatively sparse autonomic and abundant sensory fibers. Interactions between the autonomic nervous system and immune cells in lymphoid organs are known to contribute to systemic immunity, but how peripheral nerves regulate cutaneous immune responses remains unclear5,6. Here, we have exposed the skin of mice to imiquimod (IMQ), which induces IL-23 dependent psoriasis-like inflammation7,8. We show that a subset of sensory neurons expressing the ion channels TRPV1 and NaV1.8 is essential to drive this inflammatory response. Imaging of intact skin revealed that a large fraction of DDCs, the principal source of IL-23, is in close contact with these nociceptors. Upon selective pharmacological or genetic ablation of nociceptors9–11, DDCs failed to produce IL-23 in IMQ exposed skin. Consequently, the local production of IL-23 dependent inflammatory cytokines by dermal ??T17 cells and the subsequent recruitment of inflammatory cells to the skin were dramatically reduced. Intradermal injection of IL-23 bypassed the requirement for nociceptor communication with DDCs and restored the inflammatory response12. These findings indicate that TRPV1+NaV1.8+ nociceptors, by interacting with DDCs, regulate the IL-23/IL-17 pathway and control cutaneous immune responses. PMID:24759321

  19. Aspirin Desensitization

    MedlinePLUS

    ... the same as allergies to dust mites, cats, dogs, or pollen. Others believe sensitivity to aspirin results from a problem in certain chemical pathways that produce inflammatory chemicals in the body. Some believe there are genetic causes. diagnosis A thorough history and examination is ...

  20. Sensory innervation of normal and hypospadiac prepuce: possible implications in hypospadiology.

    PubMed

    Nazir, Zafar; Masood, Rehan; Rehman, Resham

    2004-08-01

    Sensory innervation of the skin influences wound healing through the release of neuropeptides from the nerve endings. The purpose of this study was to investigate the differences in the sensory innervation of the normal and the hypospadiac prepuce. The prepuce from 10 healthy children undergoing routine circumcision and 10 age-matched children undergoing hypospadias repair were submitted for immunohistochemistry, using antibodies against protein gene product (PGP) 9.5, calcitonin gene-related peptide (CGRP), and substance P (SP). The hypospadiac prepuce was found to be hypo-innervated for PGP 9.5 and CGRP positive nerves when compared with the normal prepuce ( p<0.05). The number of SP-positive nerves were increased in the hypospadiac prepuce, but not to statistical significance ( p=0.06, confidence interval >95%). There may be differences in the sensory innervation of the normal and hypospadiac prepuce. These differences in tissue environment may partly explain the postoperative edema, poor wound healing leading to urethrocutaneous fistula (UF), and increased analgesia requirements in patients undergoing hypospadias surgery. PMID:15449086

  1. S1 nerve is the most efficient nerve rootlet innervating the anal canal and rectum in rats

    PubMed Central

    Fu, Kai; Luo, Pengbo; Zheng, Xianyou; Zhu, Xiaozhong; Wang, Lei; Chai, Yimin

    2015-01-01

    Autonomic and somatic components participate in the defecation process in mammals, combining signals from the brainstem and forebrain. The innervation pattern involved in micturition in rats has been well studied, while defecation has been less studied. The aim of the present study was to identify the most important sensory and motor nerves of the anal canal and rectum involved in defecation. The amplitudes of evoked potential of the anal canal and rectum were higher when L6 and S1 ventral rootlets were stimulated, compared with the other segments (ANOVA and Tukey’s post hoc test, all P?nerves innervate the anal canal and rectum and are involved in defecation, but the S1 nerve rootlet could be the most efficient one. These results could provide a basis for defecation reconstruction, especially for patients with spinal cord injuries. PMID:26260583

  2. Brain imaging signatures of the relationship between epidermal nerve fibers and heat pain perception.

    PubMed

    Tseng, Ming-Tsung; Kong, Yazhuo; Chiang, Ming-Chang; Chao, Chi-Chao; Tseng, Wen-Yih I; Hsieh, Sung-Tsang

    2015-11-15

    Although the small-diameter primary afferent fibers in the skin promptly respond to nociceptive stimuli and convey sensory inputs to the central nervous system, the neural signatures that underpin the relationship between cutaneous afferent fibers and pain perception remain elusive. We combined skin biopsy at the lateral aspect of the distal leg, which is used to quantify cutaneous afferent fibers, with fMRI, which is used to assess brain responses and functional connectivity, to investigate the relationship between cutaneous sensory nerves and the corresponding pain perception in the brain after applying heat pain stimulation to the dorsum of the right foot in healthy subjects. During painful stimulation, the degree of cutaneous innervation, as measured by epidermal nerve fiber density, was correlated with individual blood oxygen level-dependent (BOLD) signals of the posterior insular cortex and of the thalamus, periaqueductal gray, and rostral ventromedial medulla. Pain perception was associated with the activation of the anterior insular cortex and with the functional connectivity from the anterior insular cortex to the primary somatosensory cortex during painful stimulation. Most importantly, both epidermal nerve fiber density and activity in the posterior insular cortex showed a positive correlation with the strength of coupling under pain between the anterior insular cortex and the primary somatosensory cortex. Thus, our findings support the notion that the neural circuitry subserving pain perception interacts with the cerebral correlates of peripheral nociceptive fibers, which implicates an indirect role for skin nerves in human pain perception. PMID:26279210

  3. Peptidomics and Secretomics of the Mammalian Peripheral Sensory-Motor System

    NASA Astrophysics Data System (ADS)

    Tillmaand, Emily G.; Yang, Ning; Kindt, Callie A. C.; Romanova, Elena V.; Rubakhin, Stanislav S.; Sweedler, Jonathan V.

    2015-09-01

    The dorsal root ganglion (DRG) and its anatomically and functionally associated spinal nerve and ventral and dorsal roots are important components of the peripheral sensory-motor system in mammals. The cells within these structures use a number of peptides as intercellular signaling molecules. We performed a variety of mass spectrometry (MS)-based characterizations of peptides contained within and secreted from these structures, and from isolated and cultured DRG cells. Liquid chromatography-Fourier transform MS was utilized in DRG and nerve peptidome analysis. In total, 2724 peptides from 296 proteins were identified in tissue extracts. Neuropeptides are among those detected, including calcitonin gene-related peptide I, little SAAS, and known hemoglobin-derived peptides. Solid phase extraction combined with direct matrix-assisted laser desorption/ionization time-of-flight MS was employed to investigate the secretome of these structures. A number of peptides were detected in the releasate from semi-intact preparations of DRGs and associated nerves, including neurofilament- and myelin basic protein-related peptides. A smaller set of analytes was observed in releasates from cultured DRG neurons. The peptide signals observed in the releasates have been mass-matched to those characterized and identified in homogenates of entire DRGs and associated nerves. This data aids our understanding of the chemical composition of the mammalian peripheral sensory-motor system, which is involved in key physiological functions such as nociception, thermoreception, itch sensation, and proprioception.

  4. Peptidomics and Secretomics of the Mammalian Peripheral Sensory-Motor System.

    PubMed

    Tillmaand, Emily G; Yang, Ning; Kindt, Callie A C; Romanova, Elena V; Rubakhin, Stanislav S; Sweedler, Jonathan V

    2015-12-01

    The dorsal root ganglion (DRG) and its anatomically and functionally associated spinal nerve and ventral and dorsal roots are important components of the peripheral sensory-motor system in mammals. The cells within these structures use a number of peptides as intercellular signaling molecules. We performed a variety of mass spectrometry (MS)-based characterizations of peptides contained within and secreted from these structures, and from isolated and cultured DRG cells. Liquid chromatography-Fourier transform MS was utilized in DRG and nerve peptidome analysis. In total, 2724 peptides from 296 proteins were identified in tissue extracts. Neuropeptides are among those detected, including calcitonin gene-related peptide I, little SAAS, and known hemoglobin-derived peptides. Solid phase extraction combined with direct matrix-assisted laser desorption/ionization time-of-flight MS was employed to investigate the secretome of these structures. A number of peptides were detected in the releasate from semi-intact preparations of DRGs and associated nerves, including neurofilament- and myelin basic protein-related peptides. A smaller set of analytes was observed in releasates from cultured DRG neurons. The peptide signals observed in the releasates have been mass-matched to those characterized and identified in homogenates of entire DRGs and associated nerves. This data aids our understanding of the chemical composition of the mammalian peripheral sensory-motor system, which is involved in key physiological functions such as nociception, thermoreception, itch sensation, and proprioception. PMID:26392278

  5. Breaking the Covalent Bond—A Pigment Property that Contributes to Desensitization in Cones

    PubMed Central

    Kefalov, Vladimir J.; Estevez, Maureen E.; Kono, Massahiro; Goletz, Patrice W.; Crouch, Rosalie K.; Cornwall, M. Carter; Yau, King-Wai

    2010-01-01

    Summary Retinal rod and cone pigments consist of an apoprotein, opsin, covalently linked to a chromophore, 11-cis retinal. Here we demonstrate that the formation of the covalent bond between opsin and 11-cis retinal is reversible in darkness in amphibian red cones, but essentially irreversible in red rods. This dissociation, apparently a general property of cone pigments, results in a surprisingly large amount of free opsin—about 10% of total opsin—in dark-adapted red cones. We attribute this significant level of free opsin to the low concentration of intracellular free 11-cis retinal, estimated to be only a tiny fraction (~0.1 %) of the pigment content in red cones. With its constitutive transducin-stimulating activity, the free cone opsin produces an ~2-fold desensitization in red cones, equivalent to that produced by a steady light causing 500 photoisomerizations s?1. Cone pigment dissociation therefore contributes to the sensitivity difference between rods and cones. PMID:15953417

  6. High-fidelity transmission of sensory information by single cerebellar mossy fibre boutons.

    PubMed

    Rancz, Ede A; Ishikawa, Taro; Duguid, Ian; Chadderton, Paul; Mahon, Séverine; Häusser, Michael

    2007-12-20

    Understanding the transmission of sensory information at individual synaptic connections requires knowledge of the properties of presynaptic terminals and their patterns of firing evoked by sensory stimuli. Such information has been difficult to obtain because of the small size and inaccessibility of nerve terminals in the central nervous system. Here we show, by making direct patch-clamp recordings in vivo from cerebellar mossy fibre boutons-the primary source of synaptic input to the cerebellar cortex-that sensory stimulation can produce bursts of spikes in single boutons at very high instantaneous firing frequencies (more than 700 Hz). We show that the mossy fibre-granule cell synapse exhibits high-fidelity transmission at these frequencies, indicating that the rapid burst of excitatory postsynaptic currents underlying the sensory-evoked response of granule cells can be driven by such a presynaptic spike burst. We also demonstrate that a single mossy fibre can trigger action potential bursts in granule cells in vitro when driven with in vivo firing patterns. These findings suggest that the relay from mossy fibre to granule cell can act in a 'detonator' fashion, such that a single presynaptic afferent may be sufficient to transmit the sensory message. This endows the cerebellar mossy fibre system with remarkable sensitivity and high fidelity in the transmission of sensory information. PMID:18097412

  7. Role of calcium desensitization in the treatment of myocardial dysfunction after deep hypothermic circulatory arrest

    PubMed Central

    2013-01-01

    Introduction Rewarming from deep hypothermic circulatory arrest (DHCA) produces calcium desensitization by troponin I (cTnI) phosphorylation which results in myocardial dysfunction. This study investigated the acute overall hemodynamic and metabolic effects of epinephrine and levosimendan, a calcium sensitizer, on myocardial function after rewarming from DHCA. Methods Forty male Wistar rats (400 to 500 g) underwent cardiopulmonary bypass (CPB) through central cannulation and were cooled to a core temperature of 13°C to 15°C within 30 minutes. After DHCA (20 minutes) and CPB-assisted rewarming (60 minutes) rats were randomly assigned to 60 minute intravenous infusion with levosimendan (0.2 ?g/kg/min; n?=?15), epinephrine (0.1 ?g/kg/min; n?=?15) or saline (control; n?=?10). Systolic and diastolic functions were evaluated at different preloads with a conductance catheter. Results The slope of left ventricular end-systolic pressure volume relationship (Ees) and preload recruitable stroke work (PRSW) recovered significantly better with levosimendan compared to epinephrine (Ees: 85?±?9% vs 51?±?11%, P<0.003 and PRSW: 78?±?5% vs 48?±?8%, P<0.005; baseline: 100%). Levosimendan but not epinephrine reduced left ventricular stiffness shown by the end-diastolic pressure-volume relationship and improved ventricular relaxation (Tau). Levosimendan preserved ATP myocardial content as well as energy charge and reduced plasma lactate concentrations. In normothermia experiments epinephrine in contrast to Levosimendan increased cTnI phosphorylation 3.5-fold. After rewarming from DHCA, cTnI phosphorylation increased 4.5-fold in the saline and epinephrine group compared to normothermia but remained unchanged with levosimendan. Conclusions Levosimendan due to prevention of calcium desensitization by cTnI phosphorylation is more effective than epinephrine for treatment of myocardial dysfunction after rewarming from DHCA. PMID:24138817

  8. ?-Adrenergic receptor desensitization in man: insight into post-exercise attenuation of cardiac function

    PubMed Central

    Hart, Emma; Dawson, Ellen; Rasmussen, Peter; George, Keith; Secher, Niels H; Whyte, Greg; Shave, Rob

    2006-01-01

    Desensitization of the ?-adrenoreceptors (?-AR) may contribute to a post-exercise reduction in left ventricular (LV) function. However, attenuation of the chronotropic and inotropic responses to a ?-AR agonist may depend upon alterations in parasympathetic tone. Furthermore, changes in cardiac output Q? and LV diastolic function in response to a ?-AR agonist, pre- to post-prolonged exercise, remain unclear. Seven trained males (mean ± s.d., age 27 ± 6 years) performed 4 h of ergometer rowing. Peak heart rate (HR) and LV systolic and diastolic functional responses to incremental isoproterenol (isoprenaline) infusion (2, 4 and 6 ?g kg min?1) were assessed after vagal blockade (glycopyrrolate, 1.2 mg). LV systolic function was assessed by the pressure/volume ratio (systolic blood pressure/end systolic volume) and Q?, whilst diastolic function was evaluated as peak early and late transmitral filling velocities. Following exercise, the pressure/volume ratio decreased by 25% (P < 0.05), whereas Q? was unchanged (P > 0.05). The early/late filling ratio was reduced by 36% after exercise, due to an elevation in late LV filling (P < 0.01). The increase in HR response to isoproterenol infusion was blunted post-exercise at both 4 and 6 ?g kg min?1 (127 ± 7 and 132 ± 6 beats min?1) compared with pre-exercise (138 ± 8 and 141 ± 12 beats min?1, P < 0.05). Additionally, the pressure/volume ratio and Q? were blunted post-exercise in response to isoproterenol (P < 0.05). In contrast, diastolic function was similar before and after exercise during isoproterenol infusion (P > 0.05). Desensitization of the ?-AR contributes to an attenuated left ventricular systolic but not diastolic function following prolonged exercise. PMID:16973702

  9. Desensitization to Media Violence: Links With Habitual Media Violence Exposure, Aggressive Cognitions, and Aggressive Behavior

    PubMed Central

    Krahé, Barbara; Möller, Ingrid; Huesmann, L. Rowell; Kirwil, Lucyna; Felber, Juliane; Berger, Anja

    2015-01-01

    This study examined the links between desensitization to violent media stimuli and habitual media violence exposure as a predictor and aggressive cognitions and behavior as outcome variables. Two weeks after completing measures of habitual media violence exposure, trait aggression, trait arousability, and normative beliefs about aggression, undergraduates (N = 303) saw a violent film clip and a sad or a funny comparison clip. Skin conductance level (SCL) was measured continuously, and ratings of anxious and pleasant arousal were obtained after each clip. Following the clips, participants completed a lexical decision task to measure accessibility of aggressive cognitions and a competitive reaction time task to measure aggressive behavior. Habitual media violence exposure correlated negatively with SCL during violent clips and positively with pleasant arousal, response times for aggressive words, and trait aggression, but it was unrelated to anxious arousal and aggressive responding during the reaction time task. In path analyses controlling for trait aggression, normative beliefs, and trait arousability, habitual media violence exposure predicted faster accessibility of aggressive cognitions, partly mediated by higher pleasant arousal. Unprovoked aggression during the reaction time task was predicted by lower anxious arousal. Neither habitual media violence usage nor anxious or pleasant arousal predicted provoked aggression during the laboratory task, and SCL was unrelated to aggressive cognitions and behavior. No relations were found between habitual media violence viewing and arousal in response to the sad and funny film clips, and arousal in response to the sad and funny clips did not predict aggressive cognitions or aggressive behavior on the laboratory task. This suggests that the observed desensitization effects are specific to violent content. PMID:21186935

  10. ABO desensitization affects cellular immunity and infection control after renal transplantation.

    PubMed

    Schachtner, Thomas; Stein, Maik; Reinke, Petra

    2015-10-01

    The impact of ABO desensitization on overall immunity, infectious control, and alloreactivity remains unknown. We compared 35 ABO-incompatible kidney transplant recipients (KTRs) to a control of 62 ABO compatible KTRs. Samples were collected before, at +1, +2, +3, +6, and +12 months post-transplantation. CMV-, BKV-specific, and alloreactive T cells were measured using an interferon-? ELISPOT assay. The extent of immunosuppression was quantified by enumeration of lymphocyte subpopulations and cytokines. No differences were observed for 5-year allograft survival and function between both groups (P > 0.05). However, ABO-incompatible KTRs were more likely to develop CMV infection, BKV-associated nephropathy, and severe sepsis (P = 0.001). Interestingly, ABO-incompatible KTRs with poor HLA-match showed the highest rates of infections and inferior allograft function (P < 0.05). CD3+, CD4+ T-cell counts, interferon-? and IL-10 levels were lower in ABO-incompatible KTRs early post-transplantation (P < 0.05). Likewise, ABO-incompatible KTRs showed impaired BKV- and CMV-specific T-cell immunity (P < 0.05). ABO-incompatible KTRs showed lower frequencies of alloreactive T cells (P < 0.05). Our data suggest T-cell depletion due to ABO desensitization, which may contribute to the increased risk of T-cell-dependent infections. Elimination of B cells serving as antigen-presenting cells, thereby causing impaired T-cell activation, plays a significant role in both impaired infection control and reduced alloreactive T-cell activation. PMID:26033637

  11. From nerve net to nerve ring, nerve cord and brain - evolution of the nervous system.

    PubMed

    Arendt, Detlev; Tosches, Maria Antonietta; Marlow, Heather

    2015-12-17

    The puzzle of how complex nervous systems emerged remains unsolved. Comparative studies of neurodevelopment in cnidarians and bilaterians suggest that this process began with distinct integration centres that evolved on opposite ends of an initial nerve net. The 'apical nervous system' controlled general body physiology, and the 'blastoporal nervous system' coordinated feeding movements and locomotion. We propose that expansion, integration and fusion of these centres gave rise to the bilaterian nerve cord and brain. PMID:26675821

  12. Bladder sensory physiology: neuroactive compounds and receptors, sensory transducers, and target-derived growth factors as targets to improve function

    PubMed Central

    Gonzalez, Eric J.; Merrill, Liana

    2014-01-01

    Urinary bladder dysfunction presents a major problem in the clinical management of patients suffering from pathological conditions and neurological injuries or disorders. Currently, the etiology underlying altered visceral sensations from the urinary bladder that accompany the chronic pain syndrome, bladder pain syndrome (BPS)/interstitial cystitis (IC), is not known. Bladder irritation and inflammation are histopathological features that may underlie BPS/IC that can change the properties of lower urinary tract sensory pathways (e.g., peripheral and central sensitization, neurochemical plasticity) and contribute to exaggerated responses of peripheral bladder sensory pathways. Among the potential mediators of peripheral nociceptor sensitization and urinary bladder dysfunction are neuroactive compounds (e.g., purinergic and neuropeptide and receptor pathways), sensory transducers (e.g., transient receptor potential channels) and target-derived growth factors (e.g., nerve growth factor). We review studies related to the organization of the afferent limb of the micturition reflex and discuss neuroplasticity in an animal model of urinary bladder inflammation to increase the understanding of functional bladder disorders and to identify potential novel targets for development of therapeutic interventions. Given the heterogeneity of BPS/IC and the lack of consistent treatment benefits, it is unlikely that a single treatment directed at a single target in micturition reflex pathways will have a mass benefit. Thus, the identification of multiple targets is a prudent approach, and use of cocktail treatments directed at multiple targets should be considered. PMID:24760999

  13. The effect of spinal cord injury on the neurochemical properties of vagal sensory neurons.

    PubMed

    Herrity, April N; Petruska, Jeffrey C; Stirling, David P; Rau, Kristofer K; Hubscher, Charles H

    2015-06-15

    The vagus nerve is composed primarily of nonmyelinated sensory neurons whose cell bodies are located in the nodose ganglion (NG). The vagus has widespread projections that supply most visceral organs, including the bladder. Because of its nonspinal route, the vagus nerve itself is not directly damaged from spinal cord injury (SCI). Because most viscera, including bladder, are dually innervated by spinal and vagal sensory neurons, an impact of SCI on the sensory component of vagal circuitry may contribute to post-SCI visceral pathologies. To determine whether SCI, in male Wistar rats, might impact neurochemical characteristics of NG neurons, immunohistochemical assessments were performed for P2X3 receptor expression, isolectin B4 (IB4) binding, and substance P expression, three known injury-responsive markers in sensory neuronal subpopulations. In addition to examining the overall population of NG neurons, those innervating the urinary bladder also were assessed separately. All three of the molecular markers were represented in the NG from noninjured animals, with the majority of the neurons binding IB4. In the chronically injured rats, there was a significant increase in the number of NG neurons expressing P2X3 and a significant decrease in the number binding IB4 compared with noninjured animals, a finding that held true also for the bladder-innervating population. Overall, these results indicate that vagal afferents, including those innervating the bladder, display neurochemical plasticity post-SCI that may have implications for visceral homeostatic mechanisms and nociceptive signaling. PMID:25855310

  14. Phrenic nerve transfer to the musculocutaneous nerve for the repair of brachial plexus injury: electrophysiological characteristics

    PubMed Central

    Liu, Ying; Xu, Xun-cheng; Zou, Yi; Li, Su-rong; Zhang, Bin; Wang, Yue

    2015-01-01

    Phrenic nerve transfer is a major dynamic treatment used to repair brachial plexus root avulsion. We analyzed 72 relevant articles on phrenic nerve transfer to repair injured brachial plexus that were indexed by Science Citation Index. The keywords searched were brachial plexus injury, phrenic nerve, repair, surgery, protection, nerve transfer, and nerve graft. In addition, we performed neurophysiological analysis of the preoperative condition and prognosis of 10 patients undergoing ipsilateral phrenic nerve transfer to the musculocutaneous nerve in our hospital from 2008 to 201 3 and observed the electromyograms of the biceps brachii and motor conduction function of the musculocutaneous nerve. Clinically, approximately 28% of patients had brachial plexus injury combined with phrenic nerve injury, and injured phrenic nerve cannot be used as a nerve graft. After phrenic nerve transfer to the musculocutaneous nerve, the regenerated potentials first appeared at 3 months. Recovery of motor unit action potential occurred 6 months later and became more apparent at 12 months. The percent of patients recovering ‘excellent’ and ‘good’ muscle strength in the biceps brachii was 80% after 18 months. At 12 months after surgery, motor nerve conduction potential appeared in the musculocutaneous nerve in seven cases. These data suggest that preoperative evaluation of phrenic nerve function may help identify the most appropriate nerve graft in patients with an injured brachial plexus. The functional recovery of a transplanted nerve can be dynamically observed after the surgery. PMID:25883637

  15. Chitosan conduits combined with nerve growth factor microspheres repair facial nerve defects

    PubMed Central

    Liu, Huawei; Wen, Weisheng; Hu, Min; Bi, Wenting; Chen, Lijie; Liu, Sanxia; Chen, Peng; Tan, Xinying

    2013-01-01

    Microspheres containing nerve growth factor for sustained release were prepared by a compound method, and implanted into chitosan conduits to repair 10-mm defects on the right buccal branches of the facial nerve in rabbits. In addition, chitosan conduits combined with nerve growth factor or normal saline, as well as autologous nerve, were used as controls. At 90 days post-surgery, the muscular atrophy on the right upper lip was more evident in the nerve growth factor and normal sa-line groups than in the nerve growth factor-microspheres and autologous nerve groups. physiological analysis revealed that the nerve conduction velocity and amplitude were significantly higher in the nerve growth factor-microspheres and autologous nerve groups than in the nerve growth factor and normal saline groups. Moreover, histological observation illustrated that the di-ameter, number, alignment and myelin sheath thickness of myelinated nerves derived from rabbits were higher in the nerve growth factor-microspheres and autologous nerve groups than in the nerve growth factor and normal saline groups. These findings indicate that chitosan nerve conduits bined with microspheres for sustained release of nerve growth factor can significantly improve facial nerve defect repair in rabbits. PMID:25206635

  16. Comparison of short- with long-term regeneration results after digital nerve reconstruction with muscle-in-vein conduits

    PubMed Central

    Schiefer, Jennifer Lynn; Schulz, Lukas; Rath, Rebekka; Stahl, Stéphane; Schaller, Hans-Eberhard; Manoli, Theodora

    2015-01-01

    Muscle-in-vein conduits are used alternatively to nerve grafts for bridging nerve defects. The purpose of this study was to examine short- and long-term regeneration results after digital nerve reconstruction with muscle-in-vein conduits. Static and moving two-point discriminations and Semmes-Weinstein Monofilaments were used to evaluate sensory recovery 6–12 months and 14–35 months after repair of digital nerves with muscle-in-vein in 7 cases. Both follow-ups were performed after clinical signs of progressing regeneration disappeared. In 4 of 7 cases, a further recovery of both two-point discriminations and in another case of only the static two-point discrimination of 1–3 mm could be found between the short-term and long-term follow-up examination. Moreover, a late recovery of both two-point discriminations was demonstrated in another case. Four of 7 cases showed a sensory improvement by one Semmes-Weinstein Monofilaments. This pilot study suggests that sensory recovery still takes place even when clinical signs of progressing regeneration disappear.

  17. Hydrodynamic properties of the gonadotropin receptor from a murine Leydig tumor cell line are altered by desensitization

    SciTech Connect

    Rebois, R.V.; Bradley, R.M.; Titlow, C.C.

    1987-10-06

    The murine Leydig tumor cell line 1 (MLTC-1) contains gonadotropin receptors (GR) that are coupled to adenylate cyclase through the stimulatory guanine nucleotide binding protein (G/sub s/). The binding of human choriogonadotropin (hGC) causes MLTC-1 cells to accumulate cAMP. With time, the ability of MLTC-1 cells to respond to hCG is attenuated by a process called desensitization. The hydrodynamic properties of GR from control and desensitized MLTC-1 cells were studied. Sucrose density gradient sedimentation in H/sub 2/O and D/sub 2/O and gel filtration chromatography were used to estimate the Stokes radius (a), partial specific volume (v/sub c/), sedimentation coefficient (s/sub 20,w/), and molecular weight (M/sub r/) of the detergent-solubilized hormone-receptor complex (hCG-GR). (/sup 125/I)hCG was bound to MLTC-1 cells under conditions that allow (37/sup 0/C) or prevent (0/sup 0/C) desensitization, and hCG-GR was solubilized in Triton X-100. In the absence of desensitization, control hCG-GR had a M/sub r/ of 213,000, whereas desensitized hCG-GR had a M/sub r/ of 158,000. Deglycosylated hCG (DG-HCG) is an antagonist that binds to GR with high affinity but fails to stimulate adenylate cyclase or cause desensitization. (/sup 125/I)DG-hCG was bound to MLTC-1 cells and DG-hCG-GR solubilized in Triton X-100. The hydrodynamic properties of DG-hCG-GR were the same as that for control hCG-GR. There was no evidence for the association of adenylate cyclase or G/sub s/ with GR in Triton X-100 solubilized preparations. When hCG was cross-linked to GR and solubilized with sodium dodecyl sulfate (SDS), the M/sub r/ was found to be 116,000, which was similar to that determined by SDS-polyacrylamide gel electrophoresis and less than that of the Triton X-100 solubilized control hCG-GR.

  18. ENU mutagenesis identifies mice modeling Warburg Micro Syndrome with sensory axon degeneration caused by a deletion in Rab18.

    PubMed

    Cheng, Chih-Ya; Wu, Jaw-Ching; Tsai, Jin-Wu; Nian, Fang-Shin; Wu, Pei-Chun; Kao, Lung-Sen; Fann, Ming-Ji; Tsai, Shih-Jen; Liou, Ying-Jay; Tai, Chin-Yin; Hong, Chen-Jee

    2015-05-01

    Mutations in the gene of RAB18, a member of Ras superfamily of small G-proteins, cause Warburg Micro Syndrome (WARBM) which is characterized by defective neurodevelopmental and ophthalmological phenotypes. Despite loss of Rab18 had been reported to induce disruption of the endoplasmic reticulum structure and neuronal cytoskeleton organization, parts of the pathogenic mechanism caused by RAB18 mutation remain unclear. From the N-ethyl-N-nitrosourea (ENU)-induced mutagenesis library, we identified a mouse line whose Rab18 was knocked out. This Rab18(-/-) mouse exhibited stomping gait, smaller testis and eyes, mimicking several features of WARBM. Rab18(-/-) mice were obviously less sensitive to pain and touch than WT mice. Histological examinations on Rab18(-/-) mice revealed progressive axonal degeneration in the optic nerves, dorsal column of the spinal cord and sensory roots of the spinal nerves while the motor roots were spared. All the behavioral and pathological changes that resulted from abnormalities in the sensory axons were prevented by introducing an extra copy of Rab18 transgene in Rab18(-/-) mice. Our results reveal that sensory axonal degeneration is the primary cause of stomping gait and progressive weakness of the hind limbs in Rab18(-/-) mice, and optic nerve degeneration should be the major pathology of progressive optic atrophy in children with WARBM. Our results indicate that the sensory nervous system is more vulnerable to Rab18 deficiency and WARBM is not only a neurodevelopmental but also neurodegenerative disease. PMID:25779931

  19. Wnt/Ryk signaling contributes to neuropathic pain by regulating sensory neuron excitability and spinal synaptic plasticity in rats.

    PubMed

    Liu, Su; Liu, Yue-Peng; Huang, Zhi-Jiang; Zhang, Yan-Kai; Song, Angela A; Ma, Ping-Chuan; Song, Xue-Jun

    2015-12-01

    Treating neuropathic pain continues to be a major clinical challenge and underlying mechanisms of neuropathic pain remain elusive. We have recently demonstrated that Wnt signaling, which is important in developmental processes of the nervous systems, plays critical roles in the development of neuropathic pain through the ?-catenin-dependent pathway in the spinal cord and the ?-catenin-independent pathway in primary sensory neurons after nerve injury. Here, we report that Wnt signaling may contribute to neuropathic pain through the atypical Wnt/Ryk signaling pathway in rats. Sciatic nerve injury causes a rapid-onset and long-lasting expression of Wnt3a, Wnt5b, and Ryk receptors in primary sensory neurons, and dorsal horn neurons and astrocytes. Spinal blocking of the Wnt/Ryk receptor signaling inhibits the induction and persistence of neuropathic pain without affecting normal pain sensitivity and locomotor activity. Blocking activation of the Ryk receptor with anti-Ryk antibody, in vivo or in vitro, greatly suppresses nerve injury-induced increased intracellular Ca and hyperexcitability of the sensory neurons, and also the enhanced plasticity of synapses between afferent C-fibers and the dorsal horn neurons, and activation of the NR2B receptor and the subsequent Ca-dependent signals CaMKII, Src, ERK, PKC?, and CREB in sensory neurons and the spinal cord. These findings indicate a critical mechanism underlying the pathogenesis of neuropathic pain and suggest that targeting the Wnt/Ryk signaling may be an effective approach for treating neuropathic pain. PMID:26407042

  20. Where are the sensory organs of Nybelinia surmenicola (Trypanorhyncha)? A comparative analysis with Parachristianella sp. and other trypanorhynchean cestodes.

    PubMed

    Biserova, Natalia M; Gordeev, Ilya I; Korneva, Janetta V

    2016-01-01

    The sensory organs in tegument of two trypanorhynchean species-Nybelinia surmenicola (plerocercoid) and adult Parachristianella sp. (Cestoda, Trypanorhyncha)-were studied with the aim of ultrastructural description and a comparative analysis. The Nybelinia surmenicola plerocercoid lacks papillae with sensory cilia on the bothria adhesive surface. We found an unciliated sensory organ within the median bothria fold. This unciliated free nerve ending contains the central electron-dense disc, three dense supporting rings, and broad root. The nerve ending locates in the basal matrix under the tegument. The tegument of N. surmenicola has a number of ultrastructural features which make it significantly different from other Trypanorhyncha: (i) the tegumental cytoplasm has a plicated constitution in a form of high apical and deep basal folds, (ii) numerous layers of the basal matrix are presented in the subtegument, and (iii) the squamiform and bristlelike microtriches N. surmenicola lack the base and the basal plate. In contrast, numerous ciliated and unciliated receptors were found in Parachristianella sp.: six types on the bothria and one type in the strobila tegument. Ultrastructural constitution of sensory organs in the form of ciliated free nerve endings as well as unciliated basal nerve endings of Parachristianella sp. has many common features inside Eucestoda. In comparison with other Trypanorhyncha, all Nybelinia species studied have less quantity of the bothrial sensory organs. This fact may reflect behavioral patterns of Nybelinia as well as phylogenetic position into Trypanorhyncha. Our observations of living animals conventionally demonstrate the ability of N. surmenicola plerocercoids to locomote in forward direction on the Petri dish surface. The participation of the bothrial microtriches in a parasite movement has been discussed. PMID:26443684

  1. Nerve injuries about the elbow.

    PubMed

    Hariri, Sanaz; McAdams, Timothy R

    2010-10-01

    The ulnar, radial, median, medial antebrachial cutaneous, and lateral antebrachial cutaneous nerves are subject to traction and compression in athletes who place forceful, repetitive stresses across their elbow joint. Throwing athletes are at greatest risk, and cubital tunnel syndrome (involving the ulnar nerve) is clearly the most common neuropathy about the elbow. The anatomy and innervation pattern of the nerve involved determines the characteristic of the neuropathy syndrome. The most important parts of the work-up are the history and physical examination as electrodiagnostic testing and imaging are often not reliable. In general, active rest is the first line of treatment. Tailoring the surgery and rehabilitation protocol according to the functional requirements of that athlete's sport(s) can help optimize the operative outcomes for recalcitrant cases. PMID:20883903

  2. Embryonic anastomosis between hypoglossal nerves.

    PubMed

    Rodríguez-Vázquez, J F; Mérida-Velasco, J R; Verdugo-López, S; Sanz-Casado, J V; Jiménez-Collado, J

    2009-12-01

    This article presents two cases of anastomosis of hypoglossal nerves in the suprahyoid region in human embryos of CR length 10.75 and 17.5 mm. This variation was studied in two human specimens at this stage of development and compared with the normal arrangement of the hypoglossal nerves in embryos at the same stage. The anastomotic branches were of similar caliber to the main trunks. In both cases the anastomosis was located dorsal to the origin of the geniohyoid muscles and caudal to the genioglossus muscles, lying transversally over the cranial face of the body of the hyoid bone anlage. The anastomosis formed a suprahyoid nerve chiasm on the midline in the embryo of 10.75 mm CR length. PMID:19330282

  3. Facial nerve paralysis in children

    PubMed Central

    Ciorba, Andrea; Corazzi, Virginia; Conz, Veronica; Bianchini, Chiara; Aimoni, Claudia

    2015-01-01

    Facial nerve palsy is a condition with several implications, particularly when occurring in childhood. It represents a serious clinical problem as it causes significant concerns in doctors because of its etiology, its treatment options and its outcome, as well as in little patients and their parents, because of functional and aesthetic outcomes. There are several described causes of facial nerve paralysis in children, as it can be congenital (due to delivery traumas and genetic or malformative diseases) or acquired (due to infective, inflammatory, neoplastic, traumatic or iatrogenic causes). Nonetheless, in approximately 40%-75% of the cases, the cause of unilateral facial paralysis still remains idiopathic. A careful diagnostic workout and differential diagnosis are particularly recommended in case of pediatric facial nerve palsy, in order to establish the most appropriate treatment, as the therapeutic approach differs in relation to the etiology. PMID:26677445

  4. Facial nerve paralysis in children.

    PubMed

    Ciorba, Andrea; Corazzi, Virginia; Conz, Veronica; Bianchini, Chiara; Aimoni, Claudia

    2015-12-16

    Facial nerve palsy is a condition with several implications, particularly when occurring in childhood. It represents a serious clinical problem as it causes significant concerns in doctors because of its etiology, its treatment options and its outcome, as well as in little patients and their parents, because of functional and aesthetic outcomes. There are several described causes of facial nerve paralysis in children, as it can be congenital (due to delivery traumas and genetic or malformative diseases) or acquired (due to infective, inflammatory, neoplastic, traumatic or iatrogenic causes). Nonetheless, in approximately 40%-75% of the cases, the cause of unilateral facial paralysis still remains idiopathic. A careful diagnostic workout and differential diagnosis are particularly recommended in case of pediatric facial nerve palsy, in order to establish the most appropriate treatment, as the therapeutic approach differs in relation to the etiology. PMID:26677445

  5. Palsies of Cranial Nerves That Control Eye Movement

    MedlinePLUS

    ... Medical News Palsies of Cranial Nerves That Control Eye Movement by Michael Rubin, MDCM NOTE: This is the ... Gaze Palsies Palsies of Cranial Nerves That Control Eye Movement Third Cranial Nerve (Oculomotor Nerve) Palsy Fourth Cranial ...

  6. Palsies of Cranial Nerves That Control Eye Movement

    MedlinePLUS

    ... Medical News Palsies of Cranial Nerves That Control Eye Movement By Michael Rubin, MDCM NOTE: This is the ... Gaze Palsies Palsies of Cranial Nerves That Control Eye Movement Third Cranial Nerve (Oculomotor Nerve) Palsy Fourth Cranial ...

  7. Numerical simulation of Composition B high explosive charge desensitization in gap test assembly after loading by precursor wave

    NASA Astrophysics Data System (ADS)

    Balagansky, I. A.; Stepanov, A. A.

    2015-07-01

    Results of numerical research into the desensitization of high explosive charges in water gap test-based experimental assemblies are presented. The experimental data are discussed, and the analysis using ANSYS AUTODYN 14.5 is provided. The desensitization phenomenon is well reproduced in numerical simulation using the JWL EOS and the Lee-Tarver kinetic equation for modeling of the initiation of heterogeneous high explosives with as well as without shock front waves. The analysis of the wave processes occurring during the initiation of the acceptor HE charge has been carried out. Peculiarities of the wave processes in the water gap test assemblies, which can influence the results of sensitivity measurement, have been studied. In particular, it has been established that precursor waves in the walls of the gap test assemblies can influence the detonation transmission distance.

  8. Lack of collagen XV impairs peripheral nerve maturation and, when combined with laminin-411 deficiency, leads to basement membrane abnormalities and sensorimotor dysfunction.

    PubMed

    Rasi, Karolina; Hurskainen, Merja; Kallio, Mika; Stavén, Saara; Sormunen, Raija; Heape, Anthony M; Avila, Robin L; Kirschner, Daniel; Muona, Anu; Tolonen, Uolevi; Tanila, Heikki; Huhtala, Pirkko; Soininen, Raija; Pihlajaniemi, Taina

    2010-10-27

    Although the Schwann cell basement membrane (BM) is required for normal Schwann cell terminal differentiation, the role of BM-associated collagens in peripheral nerve maturation is poorly understood. Collagen XV is a BM zone component strongly expressed in peripheral nerves, and we show that its absence in mice leads to loosely packed axons in C-fibers and polyaxonal myelination. The simultaneous lack of collagen XV and another peripheral nerve component affecting myelination, laminin ?4, leads to severely impaired radial sorting and myelination, and the maturation of the nerve is permanently compromised, contrasting with the slow repair observed in Lama4-/- single knock-out mice. Moreover, the Col15a1-/-;Lama4-/- double knock-out (DKO) mice initially lack C-fibers and, even over 1 year of age have only a few, abnormal C-fibers. The Lama4-/- knock-out results in motor and tactile sensory impairment, which is exacerbated by a simultaneous Col15a1-/- knock-out, whereas sensitivity to heat-induced pain is increased in the DKO mice. Lack of collagen XV results in slower sensory nerve conduction, whereas the Lama4-/- and DKO mice exhibit increased sensory nerve action potentials and decreased compound muscle action potentials; x-ray diffraction revealed less mature myelin in the sciatic nerves of the latter than in controls. Ultrastructural analyses revealed changes in the Schwann cell BM in all three mutants, ranging from severe (DKO) to nearly normal (Col15a1-/-). Collagen XV thus contributes to peripheral nerve maturation and C-fiber formation, and its simultaneous deletion from neural BM zones with laminin ?4 leads to a DKO phenotype distinct from those of both single knock-outs. PMID:20980607

  9. Mitochondrial dynamics and inherited peripheral nerve diseases.

    PubMed

    Pareyson, Davide; Saveri, Paola; Sagnelli, Anna; Piscosquito, Giuseppe

    2015-06-01

    Peripheral nerves have peculiar energetic requirements because of considerable length of axons and therefore correct mitochondria functioning and distribution along nerves is fundamental. Mitochondrial dynamics refers to the continuous change in size, shape, and position of mitochondria within cells. Abnormalities of mitochondrial dynamics produced by mutations in proteins involved in mitochondrial fusion (mitofusin-2, MFN2), fission (ganglioside-induced differentiation-associated protein-1, GDAP1), and mitochondrial axonal transport usually present with a Charcot-Marie-Tooth disease (CMT) phenotype. MFN2 mutations cause CMT type 2A by altering mitochondrial fusion and trafficking along the axonal microtubule system. CMT2A is an axonal autosomal dominant CMT type which in most cases is characterized by early onset and rather severe course. GDAP1 mutations also alter fission, fusion and transport of mitochondria and are associated either with recessive demyelinating (CMT4A) and axonal CMT (AR-CMT2K) and, less commonly, with dominant, milder, axonal CMT (CMT2K). OPA1 (Optic Atrophy-1) is involved in fusion of mitochondrial inner membrane, and its heterozygous mutations lead to early-onset and progressive dominant optic atrophy which may be complicated by other neurological symptoms including peripheral neuropathy. Mutations in several proteins fundamental for the axonal transport or forming the axonal cytoskeleton result in peripheral neuropathy, i.e., CMT, distal hereditary motor neuropathy (dHMN) or hereditary sensory and autonomic neuropathy (HSAN), as well as in hereditary spastic paraplegia. Indeed, mitochondrial transport involves directly or indirectly components of the kinesin superfamily (KIF5A, KIF1A, KIF1B), responsible of anterograde transport, and of the dynein complex and related proteins (DYNC1H1, dynactin, dynamin-2), implicated in retrograde flow. Microtubules, neurofilaments, and chaperones such as heat shock proteins (HSPs) also have a fundamental role in mitochondrial transport and mutations in some of related encoding genes cause peripheral neuropathy (TUBB3, NEFL, HSPB1, HSPB8, HSPB3, DNAJB2). In this review, we address the abnormalities in mitochondrial dynamics and their role in determining CMT disease and related neuropathies. PMID:25847151

  10. Nerve lesioning with direct current

    NASA Astrophysics Data System (ADS)

    Ravid, E. Natalie; Shi Gan, Liu; Todd, Kathryn; Prochazka, Arthur

    2011-02-01

    Spastic hypertonus (muscle over-activity due to exaggerated stretch reflexes) often develops in people with stroke, cerebral palsy, multiple sclerosis and spinal cord injury. Lesioning of nerves, e.g. with phenol or botulinum toxin is widely performed to reduce spastic hypertonus. We have explored the use of direct electrical current (DC) to lesion peripheral nerves. In a series of animal experiments, DC reduced muscle force by controlled amounts and the reduction could last several months. We conclude that in some cases controlled DC lesioning may provide an effective alternative to the less controllable molecular treatments available today.

  11. Peripheral nerve disease in pregnancy.

    PubMed

    Klein, Autumn

    2013-06-01

    Neuropathies during pregnancy and the postpartum period are common and are usually due to compression around pregnancy and childbirth. The most common peripheral neuropathies are Bell's palsy, carpal tunnel syndrome (CTS), and lower extremity neuropathies. Although most neuropathies are usually reversible, associated disabilities or morbidities can limit functioning and require therapy. Nerve conduction study tests and imaging should only be considered if symptoms are unusual or prolonged. Some neuropathies may be associated with preeclampsia or an inherent underlying neuropathy that increases the risk of nerve injury. All neuropathies in pregnancy should be followed as some may be persistent and require follow-up. PMID:23563878

  12. Sensory Transduction in Caenorhabditis elegans

    NASA Astrophysics Data System (ADS)

    Brown, Austin L.; Ramot, Daniel; Goodman, Miriam B.

    The roundworm Caenorhabditis elegans has a well-defined and comparatively simple repertoire of sensory-guided behaviors, all of which rely on its ability to detect chemical, mechanical or thermal stimuli. In this chapter, we review what is known about the ion channels that mediate sensation in this remarkable model organism. Genetic screens for mutants defective in sensory-guided behaviors have identified genes encoding channel proteins, which are likely transducers of chemical, thermal, and mechanical stimuli. Such classical genetic approaches are now being coupled with molecular genetics and in vivo cellular physiology to elucidate how these channels are activated in specific sensory neurons. The ion channel superfamilies implicated in sensory transduction in C. elegans - CNG, TRP, and DEG/ENaC - are conserved across phyla and also appear to contribute to sensory transduction in other organisms, including vertebrates. What we learn about the role of these ion channels in C. elegans sensation is likely to illuminate analogous processes in other animals, including humans.

  13. The L1-type cell adhesion molecule Neuroglian is necessary for maintenance of sensory axon advance in the Drosophila embryo

    PubMed Central

    Martin, Veronica; Mrkusich, Eli; Steinel, Martin C; Rice, Jason; Merritt, David J; Whitington, Paul M

    2008-01-01

    Background Cell adhesion molecules have long been implicated in the regulation of axon growth, but the precise cellular roles played by individual cell adhesion molecules and the molecular basis for their action are still not well understood. We have used the sensory system of the Drosophila embryo to shed light on the mechanism by which the L1-type cell adhesion molecule Neuroglian regulates axon growth. Results We have found a highly penetrant sensory axon stalling phenotype in neuroglian mutant embryos. Axons stalled at a variety of positions along their normal trajectory, but most commonly in the periphery some distance along the peripheral nerve. All lateral and dorsal cluster sensory neurons examined, except for the dorsal cluster neuron dbd, showed stalling. Sensory axons were never seen to project along inappropriate pathways in neuroglian mutants and stalled axons showed normal patterns of fasciculation within nerves. The growth cones of stalled axons possessed a simple morphology, similar to their appearance in wild-type embryos when advancing along nerves. Driving expression of the wild-type form of Neuroglian in sensory neurons alone rescued the neuroglian mutant phenotype of both pioneering and follower neurons. A partial rescue was achieved by expressing the Neuroglian extracellular domain. Over/mis-expression of Neuroglian in all neurons, oenocytes or trachea had no apparent effect on sensory axon growth. Conclusion We conclude that Neuroglian is necessary to maintain axon advance along axonal substrates, but is not required for initiation of axon outgrowth, axon fasciculation or recognition of correct growth substrates. Expression of Neuroglian in sensory neurons alone is sufficient to promote axon advance and the intracellular region of the molecule is largely dispensable for this function. It is unlikely, therefore, that Nrg acts as a molecular 'clutch' to couple adhesion of F-actin within the growth cone to the extracellular substrate. Rather, we suggest that Neuroglian mediates sensory axon advance by promoting adhesion of the surface of the growth cone to its substrate. Our finding that stalling of a pioneer sensory neuron is rescued by driving Neuroglian in sensory neurons alone may suggest that Neuroglian can act in a heterophilic fashion. PMID:18397531

  14. 21 CFR 882.5275 - Nerve cuff.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...aid in repairing the nerve (e.g., to prevent ingrowth of scar tissue) and for capping the end of the nerve to prevent the formation of neuroma (tumors). (b) Classification. Class II (performance...

  15. 21 CFR 882.5275 - Nerve cuff.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...aid in repairing the nerve (e.g., to prevent ingrowth of scar tissue) and for capping the end of the nerve to prevent the formation of neuroma (tumors). (b) Classification. Class II (performance...

  16. 21 CFR 882.5275 - Nerve cuff.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...aid in repairing the nerve (e.g., to prevent ingrowth of scar tissue) and for capping the end of the nerve to prevent the formation of neuroma (tumors). (b) Classification. Class II (performance...

  17. 21 CFR 882.5275 - Nerve cuff.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...aid in repairing the nerve (e.g., to prevent ingrowth of scar tissue) and for capping the end of the nerve to prevent the formation of neuroma (tumors). (b) Classification. Class II (performance...

  18. 21 CFR 882.5275 - Nerve cuff.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...aid in repairing the nerve (e.g., to prevent ingrowth of scar tissue) and for capping the end of the nerve to prevent the formation of neuroma (tumors). (b) Classification. Class II (performance...

  19. [Ultrasound-guided sciatic nerve block].

    PubMed

    Ota, Junichi; Hara, Kaoru

    2008-05-01

    Theoretically, sciatic nerve block can be used alone or in combination with lumbar plexus block or femoral nerve block for anesthesia and/or analgesia of lower limb surgery. However, clinical use of sciatic nerve block was limited by technical difficulties in performing the block since techniques used relies only on surface anatomical landmarks. Recent advances in ultrasound technology allow direct visualization of nerves and other surrounding structures and have increased the interest in performing many kinds of peripheral nerve blocks including sciatic nerve block. Preliminary data suggest that ultrasound-guided technique can help perform the sciatic nerve block more reliably and safely. In this article we describe the anatomy of the sciatic nerve, sonographic features, and technique of three major approaches including subgluteal, anterior, and popliteal approaches. The use of this technique for postoperative analgesia is also discussed. PMID:18516885

  20. Medial and Lateral Plantar Nerve Entrapment

    MedlinePLUS

    ... Version Medical Topics Blood Disorders Bone, Joint, and Muscle Disorders Brain, Spinal Cord, and Nerve Disorders Cancer Children's ... students Medical Topics Blood Disorders Bone, Joint, and Muscle Disorders Brain, Spinal Cord, and Nerve Disorders Cancer Children's ...

  1. Vagus Nerve Stimulation for Treating Epilepsy

    MedlinePLUS

    ... and their FAMILIES VAGUS NERVE STIMULATION FOR TREATING EPILEPSY This information sheet is provided to help you ... how vagus nerve stimulation (VNS) may help treat epilepsy. The American Academy of Neurology (AAN) is the ...

  2. Degeneration and Regeneration of Corneal Nerves in Response to HSV-1 Infection

    PubMed Central

    Chucair-Elliott, Ana J.; Zheng, Min; Carr, Daniel J. J.

    2015-01-01

    Purpose. Herpes simplex virus type 1 (HSV-1) infection is one cause of neurotrophic keratitis, characterized by decreases in corneal sensation, blink reflex, and tear secretion as consequence of damage to the sensory fibers innervating the cornea. Our aim was to characterize changes in the corneal nerve network and its function in response to HSV-1 infection. Methods. C57BL/6J mice were infected with HSV-1 or left uninfected. Corneas were harvested at predetermined times post infection (pi) and assessed for ? III tubulin, substance P, calcitonin gene-related peptide, and neurofilament H staining by immunohistochemistry (IHC). Corneal sensitivity was evaluated using a Cochet-Bonnet esthesiometer. Expression of genes associated with nerve repair was determined in corneas by real time RT-PCR, Western blotting, and IHC. Semaphorin 7A (SEMA 7A) neutralizing antibody or isotype control was subconjunctivally administered to infected mice. Results. The area of cornea occupied by ? III tubulin immunoreactivity and sensitivity significantly decreased by day 8 pi. Modified reinnervation was observed by day 30 pi without recovery of corneal sensation. Sensory fibers were lost by day 8 pi and were still absent or abnormal at day 30 pi. Expression of SEMA 7A increased at day 8 pi, localizing to corneal epithelial cells. Neutralization of SEMA 7A resulted in defective reinnervation and lower corneal sensitivity. Conclusions. Corneal sensory nerves were lost, consistent with loss of corneal sensation at day 8 pi. At day 30 pi, the cornea reinnervated but without recovering the normal arrangement of its fibers or function. SEMA 7A expression was increased at day 8pi, likely as part of a nerve regeneration mechanism. PMID:25587055

  3. Phenotyping the Function of TRPV1-Expressing Sensory Neurons by Targeted Axonal Silencing

    PubMed Central

    Brenneis, Christian; Kistner, Katrin; Puopolo, Michelino; Segal, David; Roberson, David; Sisignano, Marco; Labocha, Sandra; Ferreirós, Nerea; Strominger, Amanda; Cobos, Enrique J.; Ghasemlou, Nader; Geisslinger, Gerd; Reeh, Peter W.; Bean, Bruce P.; Woolf, Clifford J.

    2013-01-01

    Specific somatosensations may be processed by different subsets of primary afferents. C-fibers expressing heat-sensitive TRPV1 channels are proposed, for example, to be heat but not mechanical pain detectors. To phenotype in rats the sensory function of TRPV1+ afferents, we rapidly and selectively silenced only their activity, by introducing the membrane-impermeant sodium channel blocker QX-314 into these axons via the TRPV1 channel pore. Using tandem mass spectrometry we show that upon activation with capsaicin, QX-314 selectively accumulates in the cytosol only of TRPV1-expressing cells, and not in control cells. Exposure to QX-314 and capsaicin induces in small DRG neurons a robust sodium current block within 30 s. In sciatic nerves, application of extracellular QX-314 with capsaicin persistently reduces C-fiber but not A-fiber compound action potentials and this effect does not occur in TRPV1?/? mice. Behavioral phenotyping after selectively silencing TRPV1+ sciatic nerve axons by perineural injections of QX-314 and capsaicin reveals deficits in heat and mechanical pressure but not pinprick or light touch perception. The response to intraplantar capsaicin is substantially reduced, as expected. During inflammation, silencing TRPV1+ axons abolishes heat, mechanical, and cold hyperalgesia but tactile and cold allodynia remain following peripheral nerve injury. These results indicate that TRPV1-expressing sensory neurons process particular thermal and mechanical somatosensations, and that the sensory channels activated by mechanical and cold stimuli to produce pain in naive/inflamed rats differ from those in animals after peripheral nerve injury. PMID:23283344

  4. Stimulation of the rat's sciatic nerve regeneration by local treatment with Xymedon.

    PubMed

    Masgutov, Ruslan; Raginov, Ivan; Fomina, Galina; Kozlova, Maria; Chelyshev, Yuri

    2006-01-01

    1. The possibility of a neuro-protective effect of Xymedon as a pharmacological stimulator of nerve regeneration has been studied through Schwann cells (SCs) located in the potential area of regenerating nerve fibers' growth. 2. Xymedon was injected into the silicone chamber connecting the central and peripheral stumps of the rat's sciatic nerve. Carboxymethyl cellulose was used as a depositioned medium. 3. A 0.95% concentration of Xymedon increased the sciatic nerve functional index (SFI) values on the 14th, 21st and 28th day after the operation. By day 30, the total number of survival neurons in the L5 dorsal root ganglion (DRG) on the ipsilateral side increased with the following changes in Xymedon concentration: [see text] The number of surviving sensory neurons in the group with 0.95% Xymedon increased by 36% (p < 0.05) compared with animals with depositioned medium but Xymedon free. 4. It is suggested that the positive effects of Xymedon on neural regeneration and recovery of motor function support the potential use of Xymedon for the treatment of peripheral nerve injuries. PMID:16729249

  5. The Effects of Nerve Growth Factor on Nicotinic Synaptic Transmission in Mouse Airway Parasympathetic Neurons.

    PubMed

    Weigand, Letitia A; Kwong, Kevin; Myers, Allen C

    2015-10-01

    In autonomic ganglia, acetylcholine (ACh) is released from preganglionic nerve terminals and binds to nicotinic ACh receptors (nAChRs) on postganglionic neurons, resulting in a brief, short-lived synaptic potential (fast excitatory postsynaptic potential [fEPSP]). Although nerve growth factor (NGF) is known to affect sensory and sympathetic nerves, especially during development, little is known regarding its effect on parasympathetic nerves, especially on adult neurons. Elevated levels of NGF and NGF-mediated neural plasticity may have a role in airway diseases, such as asthma and chronic obstructive pulmonary disease. In this study, we characterize the composition and response of nAChRs in parasympathetic neurons located in lower airways of mice, and note the effects of NGF on fEPSPs and on nicotinic currents. Based on immunohistochemical staining, nAChRs are made up of ?-3 and ?-4 subunits; in addition, tropomyosin-related kinase A, the receptor for NGF, is also expressed by the neurons. Vagus nerve evoked fEPSPs and inward currents evoked by a nicotinic receptor agonist (1,1-dimethyl-4-phenylpiperazinium) were increased by NGF. NGF also affected the action potential after hyperpolarization. These studies were done in mice, which are routinely used to study airway diseases, such as asthma, where the allergen-induced contraction of airway smooth muscle has a well-defined parasympathetic cholinergic component. PMID:25647301

  6. Luteolin improves the impaired nerve functions in diabetic neuropathy: behavioral and biochemical evidences

    PubMed Central

    Li, Ming; Li, Qiang; Zhao, Qingsong; Zhang, Jinchao; Lin, Jiang

    2015-01-01

    Peripheral neuropathies are a major cause of morbidity in patients with diabetes mellitus. Up to now, drugs for improving the impaired nerve functions has been lacking for diabetic neuropathy. The antioxidant and neuroprotective effects of luteolin make it an attractive candidate for diabetic neuropathy. The present study was designed to investigate the putative beneficial effect of luteolin on diabetic neuropathy. Diabetic rats were intraperitoneally treated with daily luteolin (50 mg/kg, 100 mg/kg and 200 mg/kg) or vehicle for 3 weeks from the 28th day after streptozotocin injection. Behavioral, electrophysiological and biochemical studies were performed to evaluate the effect of luteolin on the impaired nerve functions in diabetic neuropathy. It was found that luteolin dose dependently alleviated abnormal sensation, improved nerve conduction velocities and nerve blood flow in diabetic rats. Biochanical analysis showed that luteolin significantly lowered the reactive oxygen species production and malondialdehyde level, as well as increased antioxidants activities in a dose dependent manner. In addition, luteolin significantly up-regulated the protein levels of nuclear factor-E2-related factor-2 (Nrf2) and heme oxygenase-1 (HO-1) in diabetic nerves. Taken together, luteolin is capable of improving diabetes-induced deficit in motor and sensory functions, which could be attributable, at least in part, to its Nrf2-dependent antioxidant capacity. The findings in the present study highlight the therapeutic value of luteolin for diabetic neuropathy. PMID:26617718

  7. The oral nerve plexus in amphioxus larvae: function, cell types and phylogenetic significance

    PubMed Central

    C.Lacalli, T.; J.Gilmour, T. H.; J.Kelly, S.

    1999-01-01

    Serial electron microscope reconstructions were used to examine the organization and cell types of the nerve plexus that surrounds the mouth in amphioxus larvae. The plexus is involved in a rejection response that occurs during feeding: a number of oral spines project across the mouth, and debris impinging on them triggers a contraction of the gill slit and pharyngeal musculature that forces water through the mouth, dislodging the debris. The oral spine cells are secondary sense cells that synapse with neurites belonging to a class of peripheral interneurons intrinsic to the oral nerve plexus. These in turn synapse with a second class of peripheral neurons with large axons that we interpret as sensory cells and which probably transmit signals to the nerve cord. The intrinsic cells also appear to synapse with each other, implying that local integrative activities of some complexity occur in the oral plexus. In comparative terms, the intrinsic neurons most closely resemble the Merkel-like accessory cells of vertebrate taste buds, and we postulate a homology between oral spine cells and taste buds, despite differences in function. There are also similarities between the amphioxus oral plexus and adoral nerves and ganglia of echinoderm larvae, suggesting homology of both the oral nerve plexus and the mouth itself between lower deuterostome phyla and chordates.

  8. Sensory innervation of the navicular bone and bursa in the foal.

    PubMed

    Bowker, R M; Linder, K; Sonea, I M; Holland, R E

    1995-01-01

    The sensory innervation of the navicular bone (os sesamoideum distale) and its suspensory ligaments [ligamenta sesamoidea collateralia (CSL) and ligamentum sesamoideum distale impar or distal sesamoidean impar (DS-impar) ligament] and the navicular bursa (podotrochlearis) was examined in the neonatal foal using immunocytochemistry. With antisera raised to substance P (SP) and human calcitonin gene-related peptide (CGRP), immunoreactive nerves were demonstrated to innervate the CSL and navicular bursa. Within CSL, and SP- and CGRP-like nerves were present in the synovial lining of the navicular bursa, appearing to reach the surface lining. These nerves appeared to enter the CSL and navicular bursa via the abaxial regions of the foot. Both peptides were present in the deep digital flexor tendon (DDf) along the palmar border of the navicular bursa, as well as in the DS-impar ligament. More nerve fibres were present in the dorsal part of CSL bordering the distal interphalangeal joint than was observed palmarly in CSL along the navicular bursa. Both peptides were observed to innervate the cartilage canals within the navicular bone. In terms of relative densities of immunoreactive SP- and CGRP-like peptides, the CSL dorsally and the DS-impar ligament had the highest relative densities of nerve fibres followed by the navicular bone, the palmar aspect of CSL and the DDf tendon bordering the navicular bursa. These results are discussed in relationship to local anaesthetic injections into the navicular bursa. PMID:7774550

  9. Differences in two-point discrimination and sensory threshold in the blind between braille and text reading: a pilot study

    PubMed Central

    Noh, Ji-Woong; Park, Byoung-Sun; Kim, Mee-Young; Lee, Lim-Kyu; Yang, Seung-Min; Lee, Won-Deok; Shin, Yong-Sub; Kang, Ji-Hye; Kim, Ju-Hyun; Lee, Jeong-Uk; Kwak, Taek-Yong; Lee, Tae-Hyun; Kim, Ju-Young; Kim, Junghwan

    2015-01-01

    [Purpose] This study investigated two-point discrimination (TPD) and the electrical sensory threshold of the blind to define the effect of using Braille on the tactile and electrical senses. [Subjects and Methods] Twenty-eight blind participants were divided equally into a text-reading and a Braille-reading group. We measured tactile sensory and electrical thresholds using the TPD method and a transcutaneous electrical nerve stimulator. [Results] The left palm TPD values were significantly different between the groups. The values of the electrical sensory threshold in the left hand, the electrical pain threshold in the left hand, and the electrical pain threshold in the right hand were significantly lower in the Braille group than in the text group. [Conclusion] These findings make it difficult to explain the difference in tactility between groups, excluding both palms. However, our data show that using Braille can enhance development of the sensory median nerve in the blind, particularly in terms of the electrical sensory and pain thresholds. PMID:26180348

  10. Differences in two-point discrimination and sensory threshold in the blind between braille and text reading: a pilot study.

    PubMed

    Noh, Ji-Woong; Park, Byoung-Sun; Kim, Mee-Young; Lee, Lim-Kyu; Yang, Seung-Min; Lee, Won-Deok; Shin, Yong-Sub; Kang, Ji-Hye; Kim, Ju-Hyun; Lee, Jeong-Uk; Kwak, Taek-Yong; Lee, Tae-Hyun; Kim, Ju-Young; Kim, Junghwan

    2015-06-01

    [Purpose] This study investigated two-point discrimination (TPD) and the electrical sensory threshold of the blind to define the effect of using Braille on the tactile and electrical senses. [Subjects and Methods] Twenty-eight blind participants were divided equally into a text-reading and a Braille-reading group. We measured tactile sensory and electrical thresholds using the TPD method and a transcutaneous electrical nerve stimulator. [Results] The left palm TPD values were significantly different between the groups. The values of the electrical sensory threshold in the left hand, the electrical pain threshold in the left hand, and the electrical pain threshold in the right hand were significantly lower in the Braille group than in the text group. [Conclusion] These findings make it difficult to explain the difference in tactility between groups, excluding both palms. However, our data show that using Braille can enhance development of the sensory median nerve in the blind, particularly in terms of the electrical sensory and pain thresholds. PMID:26180348

  11. Cranial Nerves any nerve that emanates from the skull Motor = efferent

    E-print Network

    Houde, Peter

    Cranial Nerves ­ any nerve that emanates from the skull Motor = efferent somatomotor ­ to skeletal, vision, gustation, hearing, equilibrium Cranial nerves - functions nI ­ olfactory, SS nII ­ optic, SS n to tongue Cranial nerves ­ pathways from anterior cranial fossa nI ­ olfactory from anterior cranial fossa

  12. The effects of three different desensitizing agents on the shear bond strength of composite resin bonding agents.

    PubMed

    Zorba, Yahya Orcun; Erdemir, Ali; Ercan, Ertugrul; Eldeniz, Ayce Unverdi; Kalaycioglu, Baris; Ulker, Mustafa

    2010-07-01

    The aim of this study was to evaluate the effects of three desensitizing agents on the shear bond strengths of four different bonding agents used to bond composite resin to dentin. A total of 160 extracted human molars were sectioned parallel to the occlusal plane under water cooling, polished and randomly divided into 4 groups of 40. Each group was treated with a different desensitizing agent (Tooth Mousse, Ultra-EZ, Cervitec Plus), except for an untreated control group. Each group was then randomly subdivided into 4 groups of 10, and a different dentin bonding agent (XP Bond, AdheSE, Adper Prompt L-pop, GBond) was applied to each group in order to bond the specimens to a resin composite (Gradia Direct) built up using a plastic apparatus. A Universal Testing Machine was used to measure the shear bond strength of each specimen. Statistical analysis was performed using one-way ANOVA and Tukey's tests. With the exception of the Control/AdheSE and Ultra-EZ/XP Bond groups, no statistically significant differences were found in the shear bond strength values of the groups tested. These findings suggest that the use of different desensitizing agents does not affect the shear bond strength of various adhesive systems used to bond resin composite to dentin. PMID:20416554

  13. Na(+)-dependent GABA transport system scavenges endogenous external GABA and prevents desensitization of GABAA receptors in rat cerebrocortical synaptoneurosomes.

    PubMed

    Im, W B; Blakeman, D P; Davis, J P

    1990-06-25

    Muscimol-induced 36Cl- uptake in rat cerebrocortical synaptoneurosomes was reduced upon exposure of the membrane sacs to low Na+ media. This Na+ requirement led us to examine the role of the Na(+)-dependent gamma-aminobutyric acid (GABA) transport system in 36Cl- uptake. Incubation of the synaptoneurosomes with nipecotic acid, a specific inhibitor of the GABA transport system, for 10 min increased the level of endogenous external GABA from less than 10 to 150 microM and induced the same signs of desensitization as observed with high muscimol-treated synaptoneurosomes; a marked reduction of muscimol-induced 36Cl- uptake and an appearance of a slow bicuculline-sensitive 36Cl- uptake, probably due to a continuous recovery of a population of GABAA receptors from desensitization. Similar results were obtained upon dissipation of Na+ electrochemical gradient across the membranes by inhibition of Na+, K(+)-ATPase with ouabain or by blocking energy metabolism with azide or N-ethylmaleimide. We propose that the Na(+)-dependent GABA transport system, its operation being dependent on inwardly directed Na+ electrochemical gradient, is responsible for scavenging endogenous GABA released from the synaptoneurosomes, and thus prevents desensitization of GABAA receptors. PMID:2169957

  14. Structure and dynamics of AMPA receptor GluA2 in resting, pre-open and desensitized states

    PubMed Central

    Dürr, Katharina L.; Chen, Lei; Stein, Richard A.; De Zorzi, Rita; MihaelaFolea, I.; Walz, Thomas; Mchaourab, Hassane S.; Gouaux, Eric

    2014-01-01

    Summary Ionotropic glutamate receptors (iGluRs) mediate the majority of fast excitatory signaling in the nervous system. Despite the profound importance of iGluRs in the nervous system, little is known about the structures and dynamics of intact receptors in distinct functional states. Here we elucidate the structures of the intact GluA2 AMPA receptor in an apo resting/closed state, in an activated/pre-open state bound with the partial agonists and a positive allosteric modulator and in a desensitized/closed state in complex with FW alone. To probe the conformational properties of these states, we carried out double electron-electron resonance experiments on cysteine mutants and cryo-electron microscopy studies. We show how agonist binding modulates the conformation of the ligand binding domain 'layer' of the intact receptors and how, upon desensitization, the receptor undergoes large conformational rearrangements of amino-terminal and ligand-binding domains. We define mechanistic principles by which to understand antagonism, activation and desensitization in AMPA iGluRs. PMID:25109876

  15. Structure-activity relationships of fatty acid amide ligands in activating and desensitizing G protein-coupled receptor 119.

    PubMed

    Kumar, Pritesh; Kumar, Akhilesh; Song, Zhao-Hui

    2014-01-15

    The purpose of the current study was to apply a high throughput assay to investigate the structure-activity relationships of fatty acid amides for activating and desensitizing G protein-coupled receptor 119, a promising therapeutic target for both type 2 diabetes and obesity. A cell-based, homogenous time resolved fluorescence (HTRF) method for measuring G protein-coupled receptor 119-mediated increase of cyclic adenosine monophosphate (cAMP) levels was validated and applied in this study. Using novel fatty acid amides and detailed potency and efficacy analyses, we have demonstrated that degree of saturation in acyl chain and charged head groups of fatty acid amides have profound effects on the ability of these compounds to activate G protein-coupled receptor 119. In addition, we have demonstrated for the first time that pretreatments with G protein-coupled receptor 119 agonists desensitize the receptor and the degrees of desensitization caused by fatty acid amides correlate well with their structure-activity relationships in activating the receptor. PMID:24184668

  16. Evidence for involvement of central vasopressin V1b and V2 receptors in stress-induced baroreflex desensitization

    PubMed Central

    Milutinovi?-Smiljani?, Sanja; Šarenac, Olivera; Lozi?-Djuri?, Maja; Murphy, David; Japundži?-Žigon, Nina

    2013-01-01

    Background and Purpose It is well recognized that vasopressin modulates the neurogenic control of the circulation. Here, we report the central mechanisms by which vasopressin modulates cardiovascular response to stress induced by immobilization. Experimental Approach Experiments were performed in conscious male Wistar rats equipped with radiotelemetric device for continuous measurement of haemodynamic parameters: systolic and diastolic BP and heart rate (HR). The functioning of the spontaneous baro-receptor reflex (BRR) was evaluated using the sequence method and the following parameters were evaluated: BRR sensitivity (BRS) and BRR effectiveness index (BEI). Key Results Under baseline physiological conditions intracerebroventricular injection of 100 and 500 ng of selective non-peptide V1a or V1b or V2 receptor antagonist did not modify BP, HR and BRR. Rats exposed to 15 min long stress by immobilization exhibited increase of BP, HR, reduction of BRS and no change in BEI. Pretreatment of rats with V1a receptor antagonist did not modulate the BP, HR, BRS and BEI response to stress. Pretreatment of rats with V1b receptor and V2 receptor antagonist, at both doses, prevented BRR desensitization and tachycardia, but failed to modulate stress-induced hypertension. Conclusions and Implications Vasopressin by the stimulation of central V1b- and V2-like receptors mediates stress-induced tachycardia and BRR desensitization. If these mechanisms are involved, BRR desensitization in heart failure and hypertension associated with poor outcome, they could be considered as novel targets for cardiovascular drug development. PMID:23488898

  17. Vascular endothelial growth factor-A165b prevents diabetic neuropathic pain and sensory neuronal degeneration.

    PubMed

    Hulse, Richard P; Beazley-Long, Nicholas; Ved, Nikita; Bestall, Samuel M; Riaz, Hamza; Singhal, Priya; Ballmer Hofer, Kurt; Harper, Steve J; Bates, David O; Donaldson, Lucy F

    2015-10-01

    Diabetic peripheral neuropathy affects up to half of diabetic patients. This neuronal damage leads to sensory disturbances, including allodynia and hyperalgesia. Many growth factors have been suggested as useful treatments for prevention of neurodegeneration, including the vascular endothelial growth factor (VEGF) family. VEGF-A is generated as two alternative splice variant families. The most widely studied isoform, VEGF-A165a is both pro-angiogenic and neuroprotective, but pro-nociceptive and increases vascular permeability in animal models. Streptozotocin (STZ)-induced diabetic rats develop both hyperglycaemia and many of the resulting diabetic complications seen in patients, including peripheral neuropathy. In the present study, we show that the anti-angiogenic VEGF-A splice variant, VEGF-A165b, is also a potential therapeutic for diabetic neuropathy. Seven weeks of VEGF-A165b treatment in diabetic rats reversed enhanced pain behaviour in multiple behavioural paradigms and was neuroprotective, reducing hyperglycaemia-induced activated caspase 3 (AC3) levels in sensory neuronal subsets, epidermal sensory nerve fibre loss and aberrant sciatic nerve morphology. Furthermore, VEGF-A165b inhibited a STZ-induced increase in Evans Blue extravasation in dorsal root ganglia (DRG), saphenous nerve and plantar skin of the hind paw. Increased transient receptor potential ankyrin 1 (TRPA1) channel activity is associated with the onset of diabetic neuropathy. VEGF-A165b also prevented hyperglycaemia-enhanced TRPA1 activity in an in vitro sensory neuronal cell line indicating a novel direct neuronal mechanism that could underlie the anti-nociceptive effect observed in vivo. These results demonstrate that in a model of Type I diabetes VEGF-A165b attenuates altered pain behaviour and prevents neuronal stress, possibly through an effect on TRPA1 activity. PMID:26201024

  18. Axial compressor blade design for desensitization of aerodynamic performance and stability to tip clearance

    NASA Astrophysics Data System (ADS)

    Erler, Engin

    Tip clearance flow is the flow through the clearance between the rotor blade tip and the shroud of a turbomachine, such as compressors and turbines. This flow is driven by the pressure difference across the blade (aerodynamic loading) in the tip region and is a major source of loss in performance and aerodynamic stability in axial compressors of modern aircraft engines. An increase in tip clearance, either temporary due to differential radial expansion between the blade and the shroud during transient operation or permanent due to engine wear or manufacturing tolerances on small blades, increases tip clearance flow and results in higher fuel consumption and higher risk of engine surge. A compressor design that can reduce the sensitivity of its performance and aerodynamic stability to tip clearance increase would have a major impact on short and long-term engine performance and operating envelope. While much research has been carried out on improving nominal compressor performance, little had been done on desensitization to tip clearance increase beyond isolated observations that certain blade designs such as forward chordwise sweep, seem to be less sensitive to tip clearance size increase. The current project aims to identify through a computational study the flow features and associated mechanisms that reduces sensitivity of axial compressor rotors to tip clearance size and propose blade design strategies that can exploit these results. The methodology starts with the design of a reference conventional axial compressor rotor followed by a parametric study with variations of this reference design through modification of the camber line and of the stacking line of blade profiles along the span. It is noted that a simple desensitization method would be to reduce the aerodynamic loading of the blade tip which would reduce the tip clearance flow and its proportional contribution to performance loss. However, with the larger part of the work on the flow done in this region, this approach would entail a nominal performance penalty. Therefore, the chosen rotor design philosophy aims to keep the spanwise loading constant to avoid trading performance for desensitization. The rotor designs that resulted from this exercise are simulated in ANSYS CFX at different tip clearance sizes. The change in their performance with respect to tip clearance size (sensitivity) is compared both on an integral level in terms of pressure ratio and adiabatic efficiency, as well as on a detailed level in terms of aerodynamic losses and blockage associated with tip clearance flow. The sensitivity of aerodynamic stability is evaluated either directly through the simulations of the rotor characteristics up to the stall point (expensive in time and resources) for a few designs or indirectly through the position of the interface between the incoming and tip clearance flow with respect to the rotor leading edge plane. The latter approach is based on a generally observed stall criteria in modern axial compressors. The rotor designs are then assessed according to their sensitivity in comparison to that of the reference rotor design to detect features that can explain the trend in sensitivity to tip clearance size. These features can then be validated and the associated flow mechanisms explained through numerical simulations and modelling. Analysis of the database from the rotor parametric study shows that the observed trend in sensitivity cannot be explained by the shifting of the aerodynamic loading along the blade chord, as initially hypothesized based on the literature review. Instead, two flow features are found to reduce sensitivity of performance and stability to tip clearance, namely an increase in incoming meridional momentum in the tip region and a reduction/elimination of double leakage flow. Double leakage flow is the flow that exits the tip clearance of one blade and proceeds into the clearance of the adjacent blade rather than convecting downstream out of the local blade passage. These flow features are isolated and validated based on the referen

  19. Proximal Sciatic Nerve Intraneural Ganglion Cyst

    PubMed Central

    Swartz, Karin R.; Wilson, Dianne; Boland, Michael; Fee, Dominic B.

    2009-01-01

    Intraneural ganglion cysts are nonneoplastic, mucinous cysts within the epineurium of peripheral nerves which usually involve the peroneal nerve at the knee. A 37-year-old female presented with progressive left buttock and posterior thigh pain. Magnetic resonance imaging revealed a sciatic nerve mass at the sacral notch which was subsequently revealed to be an intraneural ganglion cyst. An intraneural ganglion cyst confined to the proximal sciatic nerve has only been reported once prior to 2009. PMID:20069041

  20. Patterned substrates and methods for nerve regeneration

    DOEpatents

    Mallapragada, Surya K.; Heath, Carole; Shanks, Howard; Miller, Cheryl A.; Jeftinija, Srdija

    2004-01-13

    Micropatterned substrates and methods for fabrication of artificial nerve regeneration conduits and methods for regenerating nerves are provided. Guidance compounds or cells are seeded in grooves formed on the patterned substrate. The substrates may also be provided with electrodes to provide electrical guidance cues to the regenerating nerve. The micropatterned substrates give physical, chemical, cellular and/or electrical guidance cues to promote nerve regeneration at the cellular level.

  1. Peri-procedural care of renal nerve ablation candidates.

    PubMed

    Tsioufis, Costas; Dimitriadis, Kyriakos; Thomopoulos, Costas; Tsiachris, Dimitris; Kasiakogias, Alexandros; Kintis, Konstantinos; Flesas, Dimitris; Papademetriou, Vasilios; Stefanadis, Christodoulos

    2013-08-01

    Percutaneous catheter-based transluminal renal nerve ablation (RNA) by delivery of radiofrequency energy constitutes a novel therapeutic strategy for the treatment of resistant hypertension. The sympathetic nervous activation to the kidney and the sensory afferent signals to the central nervous system represent the targets of RNA. In this review we summarize current recommendations for appropriate patient selection for RNA and multimodal strategies in order to optimize pharmacological treatment for resistant hypertension. The safety and efficacy of the RNA based on published trials are also presented. Furthermore, a detailed description of the periprocedural management, the methodology of the RNA procedure and appropriate follow-up are provided. In conclusion, in order to improve the overall clinical outcome and achieve optimal management of resistant hypertensive patients before and after the RNA, experienced and certified centers are of major importance. PMID:23173966

  2. Expanded Terminal Fields of Gustatory Nerves Accompany Embryonic BDNF Overexpression in Mouse Oral Epithelia

    PubMed Central

    Sun, Chengsan; Dayal, Arjun

    2015-01-01

    Brain-derived neurotrophic factor (BDNF) is expressed in gustatory epithelia and is required for gustatory neurons to locate and innervate their correct target during development. When BDNF is overexpressed throughout the lingual epithelium, beginning embryonically, chorda tympani fibers are misdirected and innervate inappropriate targets, leading to a loss of taste buds. The remaining taste buds are hyperinnervated, demonstrating a disruption of nerve/target matching in the tongue. We tested the hypothesis here that overexpression of BDNF peripherally leads to a disrupted terminal field organization of nerves that carry taste information to the brainstem. The chorda tympani, greater superficial petrosal, and glossopharyngeal nerves were labeled in adult wild-type (WT) mice and in adult mice in which BDNF was overexpressed (OE) to examine the volume and density of their central projections in the nucleus of the solitary tract. We found that the terminal fields of the chorda tympani and greater superficial petrosal nerves and overlapping fields that included these nerves in OE mice were at least 80% greater than the respective field volumes in WT mice. The shapes of terminal fields were similar between the two groups; however, the density and spread of labels were greater in OE mice. Unexpectedly, there were also group-related differences in chorda tympani nerve function, with OE mice showing a greater relative taste response to a concentration series of sucrose. Overall, our results show that disruption in peripheral innervation patterns of sensory neurons have significant effects on peripheral nerve function and central organization of their terminal fields. PMID:25568132

  3. Alignment and composition of laminin–polycaprolactone nanofiber blends enhance peripheral nerve regeneration

    PubMed Central

    Neal, Rebekah A.; Tholpady, Sunil S.; Foley, Patricia L.; Swami, Nathan; Ogle, Roy C.; Botchwey, Edward A.

    2012-01-01

    Peripheral nerve transection occurs commonly in traumatic injury, causing deficits distal to the injury site. Conduits for repair currently on the market are hollow tubes; however, they often fail due to slow regeneration over long gaps. To facilitate increased regeneration speed and functional recovery, the ideal conduit should provide biochemically relevant signals and physical guidance cues, thus playing an active role in regeneration. To that end, laminin and laminin–polycaprolactone (PCL) blend nanofibers were fabricated to mimic peripheral nerve basement membrane. In vitro assays established 10% (wt) laminin content is sufficient to retain neurite-promoting effects of laminin. In addition, modified collector plate design to introduce an insulating gap enabled the fabrication of aligned nanofibers. The effects of laminin content and fiber orientation were evaluated in rat tibial nerve defect model. The lumens of conduits were filled with nanofiber meshes of varying laminin content and alignment to assess changes in motor and sensory recovery. Retrograde nerve conduction speed at 6 weeks was significantly faster in animals receiving aligned nanofiber conduits than in those receiving random nanofiber conduits. Animals receiving nanofiber-filled conduits showed some conduction in both anterograde and retrograde directions, whereas in animals receiving hollow conduits, no impulse conduction was detected. Aligned PCL nanofibers significantly improved motor function; aligned laminin blend nanofibers yielded the best sensory function recovery. In both cases, nanofiber-filled conduits resulted in better functional recovery than hollow conduits. These studies provide a firm foundation for the use of natural–synthetic blend electrospun nanofibers to enhance existing hollow nerve guidance conduits. PMID:22106069

  4. Peripheral Nerve Diffusion Tensor Imaging: Assessment of Axon and Myelin Sheath Integrity

    PubMed Central

    Heckel, A.; Weiler, M.; Xia, A.; Ruetters, M.; Pham, M.; Bendszus, M.; Heiland, S.; Baeumer, P.

    2015-01-01

    Purpose To investigate the potential of diffusion tensor imaging (DTI) parameters as in-vivo biomarkers of axon and myelin sheath integrity of the median nerve in the carpal tunnel as validated by correlation with electrophysiology. Methods MRI examinations at 3T including DTI were conducted on wrists in 30 healthy subjects. After manual segmentation of the median nerve quantitative analysis of fractional anisotropy (FA) as well as axial, radial and mean diffusivity (AD, RD, and MD) was carried out. Pairwise Pearson correlations with electrophysiological parameters comprising sensory nerve action potential (SNAP) and compound muscle action potential (CMAP) as markers of axon integrity, and distal motor latency (dml) and sensory nerve conduction velocity (sNCV) as markers of myelin sheath integrity were computed. The significance criterion was set at P=0.05, Bonferroni corrected for multiple comparisons. Results DTI parameters showed a distinct proximal-to-distal profile with FA, MD, and RD extrema coinciding in the center of the carpal tunnel. AD correlated with CMAP (r=0.50, p=0.04, Bonf. corr.) but not with markers of myelin sheath integrity. RD correlated with sNCV (r=-0.53, p=0.02, Bonf. corr.) but not with markers of axon integrity. FA correlated with dml (r=-0.63, p=0.002, Bonf. corr.) and sNCV (r=0.68, p=0.001, Bonf. corr.) but not with markers of axon integrity. Conclusion AD reflects axon integrity, while RD (and FA) reflect myelin sheath integrity as validated by correlation with electrophysiology. DTI parameters consistently indicate a slight decrease of structural integrity in the carpal tunnel as a physiological site of median nerve entrapment. DTI is particularly sensitive, since these findings are observed in healthy participants. Our results encourage future studies to evaluate the potential of DTI in differentiating axon from myelin sheath injury in patients with manifest peripheral neuropathies. PMID:26114630

  5. Polysialic acid glycomimetics promote myelination and functional recovery after peripheral nerve injury in mice.

    PubMed

    Mehanna, Ali; Mishra, Bibhudatta; Kurschat, Nina; Schulze, Christian; Bian, Shan; Loers, Gabriele; Irintchev, Andrey; Schachner, Melitta

    2009-06-01

    alpha2,8 Polysialic acid (PSA) is a carbohydrate attached to the glycoprotein backbone of the neural cell adhesion molecule (NCAM) and implicated in nervous system development and repair. Here, we investigated whether PSA can improve functional recovery after peripheral nerve lesion in adult mice. We applied a functional PSA mimicking peptide or a control peptide in a polyethylene cuff used to surgically reconnect the severed stumps of the femoral nerve before it bifurcates into the motor and sensory branches. Using video-based motion analysis to monitor motor recovery over a 3 month postoperative period, we observed a better functional outcome in the PSA mimetic-treated than in control mice receiving a control peptide or phosphate buffered saline. Retrograde tracing of regenerated motoneurons and morphometric analyses showed that motoneuron survival, motoneuron soma size and axonal diameters were not affected by treatment with the PSA mimetic. However, remyelination of regenerated axons distal to the injury site was considerably improved by the PSA mimetic indicating that effects on Schwann cells in the denervated nerve may underlie the functional effects seen in motor recovery. In line with this notion was the observation that the PSA mimetic enhanced the elongation of Schwann cell processes and Schwann cell proliferation in vitro, when compared with the control peptide. Moreover, Schwann cell proliferation in vivo was enhanced in both motor and sensory branches of the femoral nerve by application of the PSA mimetic. These effects were likely mediated by NCAM through its interaction with the fibroblast growth factor receptor (FGFR), since they were not observed when the PSA mimetic was applied to NCAM-deficient Schwann cells, and since application of two different FGFR inhibitors reduced process elongation from Schwann cells in vitro. Our results indicate the potential of PSA mimetics as therapeutic agents promoting motor recovery and myelination after peripheral nerve injury. PMID:19454531

  6. Chemically extracted acellular allogeneic nerve graft combined with ciliary neurotrophic factor promotes sciatic nerve repair

    PubMed Central

    Zhang, Yanru; Zhang, Hui; Katiella, Kaka; Huang, Wenhua

    2014-01-01

    A chemically extracted acellular allogeneic nerve graft can reduce postoperative immune rejection, similar to an autologous nerve graft, and can guide neural regeneration. However, it remains poorly understood whether a chemically extracted acellular allogeneic nerve graft combined with neurotrophic factors provides a good local environment for neural regeneration. This study investigated the repair of injured rat sciatic nerve using a chemically extracted acellular allogeneic nerve graft combined with ciliary neurotrophic factor. An autologous nerve anastomosis group and a chemical acellular allogeneic nerve bridging group were prepared as controls. At 8 weeks after repair, sciatic functional index, evoked potential amplitude of the soleus muscle, triceps wet weight recovery rate, total number of myelinated nerve fibers and myelin sheath thickness were measured. For these indices, values in the three groups showed the autologous nerve anastomosis group > chemically extracted acellular nerve graft + ciliary neurotrophic factor group > chemical acellular allogeneic nerve bridging group. These results suggest that chemically extracted acellular nerve grafts combined with ciliary neurotrophic factor can repair sciatic nerve defects, and that this repair is inferior to autologous nerve anastomosis, but superior to chemically extracted acellular allogeneic nerve bridging alone. PMID:25221592

  7. Use of tubulization (nerve conduits) in repairing nerve defects in children

    PubMed Central

    Sénčs, Filippo Maria; Catena, Nunzio; Sénčs, Jacopo

    2015-01-01

    Background: Direct neurorrhaphy, nerve grafting interposition and neurotization are the options for nerve repair in children, whereas few reports about using nerve conduits (tubulization) are referred to pediatrics in the literature. The authors present their experience about nerve repairing by means of nerve tubes during the developmental age when the harvesting of nerve grafts and also vein grafts of adequate caliber for bridging nerve defects is difficult. A critical review of their case series offers indications for using nerve conduits in pediatrics. Materials and Methods: Fifteen patients were treated using the nerve tubulization; nine patients were affected by obstetrical brachial plexus palsy (OBPP) while six were suffering from peripheral nerve injuries (PNIs). Results: In patients suffering from OBPP, we observed 1 good, 3 fair and 5 bad results. In the PNI group, we observed 4 patients who had good results while only 2 had a bad outcome. No fair results were observed. Conclusions: In peripheral nerve repairing in children by using nerve conduits, the outcome has been widely effective even when dealing with mixed and motor nerve, thus nerve tubulization might be considered as an alternative to nerve grafting. Conversely, considering the uncertain result obtained in brachial plexus repairing, the conduits cannot be considered as a first choice of treatment in brachial plexus reconstruction. PMID:26538763

  8. The relationship between the agonist-induced activation and desensitization of the human tachykinin NK2 receptor expressed in Xenopus oocytes

    PubMed Central

    Maudsley, S; Gent, J P; Findlay, J B C; Donnelly, D

    1998-01-01

    Repeated applications of neurokinin?A (NKA) to oocytes injected with 25?ng wild-type hNK2 receptor cRNA caused complete attenuation of second and subsequent NKA-induced responses while analogous experiments using repeated applications of GR64349 and [Nle10]NKA(4–10) resulted in no such desensitization. This behaviour has been previously attributed to the ability of the different ligands to stabilize different active conformations of the receptor that have differing susceptibilities to receptor kinases (Nemeth & Chollet, 1995).However, for Xenopus oocytes injected (into the nucleus) with 10?ng wild-type hNK2 receptor cDNA, a single 100?nM concent