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Plasma calcitonin gene-related peptide is increased prior to obesity, and sensory nerve desensitization by capsaicin improves oral glucose tolerance in obese Zucker rats  

Microsoft Academic Search

Objective: It has earlier been demonstrated that capsaicin-induced desensitization improves insulin sensitivity in normal rats. However, whether increased capsaicin-sensitive nerve activity precedes the onset of insulin resistance in diet-induced obesity - and therefore might be involved in the patho- physiology - is not known. Further, it is of relevance to investigate whether capsaicin desensitization improves glycaemic control even in obese

Dorte X Gram; Anker J Hansen; Michael Wilken; Torben Elm; Ove Svendsen; Richard D Carr; Bo Ahren; Christian L Brand



Opioids and Sensory Nerves  

Microsoft Academic Search

\\u000a This chapter reviews the expression and regulation of opioid receptors in sensory neurons and the interactions of these receptors\\u000a with endogenous and exogenous opioid ligands. Inflammation of peripheral tissues leads to increased synthesis and axonal transport\\u000a of opioid receptors in dorsal root ganglion neurons. This results in opioid receptor upregulation and enhanced G protein coupling\\u000a at peripheral sensory nerve terminals.

Christoph Stein; Christian Zöllner


Area of desensitization following mental nerve block in dogs.  


Regional nerve blocks are commonly used to provide analgesia for dental and oral surgical procedures. The purpose of this study was to demarcate the areas of the mandible that would be desensitized by application of the mental nerve block. Seven healthy mixed-breed dogs were anesthetized for an annual dental examination and professional teeth cleaning procedure. Bupivacaine HCl (0.4 ml/ m2) was administered at one middle mental foramen based on previously described techniques for the mental nerve block. A noxious stimulus was applied at 23 predetermined ipsilateral mandibular locations using pressure from a mosquito hemostat on the mucocutaneous junction (MCJ) and a dental curette on the vestibular mucogingival line (MGL) at the incisor canine, and premolar teeth; and, the mesial and distal aspects of the first molar tooth. A thermal stimulus using a refrigerant spray on a cotton ball was applied to the ipsilateral canine, third premolar and fourth premolar teeth; and, the mesial and distal aspects of the first molar tooth. Demonstration of nociception or anesthesia was noted and the responses tabulated. The area of desensitized tissues was smaller than expected and highly variable within the study group. In conclusion, the unilateral mental nerve block does not reliably provide generalized desensitization to tissues of the incisive and rostral regions of the mandible. Although the mental nerve block is recommended, other modes of analgesia should be emphasized for surgical and dental procedures involving these areas. PMID:22206140

Krug, William; Losey, Jeannie



Whole sensory nerve recordings with spiral nerve cuff electrode  

Microsoft Academic Search

We have used a self-curling nerve cuff electrode to record sensory information from a cutaneous nerve. This type of cuffs has previously been used only for stimulation, but its mechanical properties could make it very suitable for recording also, since it can be fitted closer to the nerve than traditional cuffs without compromising the nerve. In this study we show

T. Sinjar; B. Hinge; A. Jorgensen; M. L. Jensen; M. Haugland



Prolonged sensory-selective nerve blockade  

PubMed Central

Sensory-selective local anesthesia has long been a key goal in local anesthetic development. For example, it allows women to be pain-free during labor without compromising their ability to push. Here we show that prolonged sensory-selective nerve block can be produced by specific concentrations of surfactants—such as are used to enhance drug flux across skin—in combination with QX-314, a lidocaine derivative that has relative difficulty penetrating nerves. For example, injection of 25 mM QX-314 in 30 mM octyltrimethylammonium bromide (OTAB) lasted up to 7 h. Sensory selectivity was imparted to varying degrees by cationic, neutral, and anionic surfactants, and also was achieved with another lidocaine derivative, QX-222. Simultaneous injection of OTAB at a s.c. injection site remote from the sciatic nerve did not result in prolonged sensory-specific nerve blockade from QX-314, suggesting that the observed effect is due to a local interaction between the surfactant and the lidocaine derivative, not a systemic effect.

Sagie, Itay; Kohane, Daniel S.



Deep peroneal nerve transfer for established plantar sensory loss.  


Patients with established or irreversible plantar sensory loss often have normal sensation on the dorsal aspect of the foot, due to an intact deep peroneal nerve. A new method of deep peroneal nerve transfer is proposed for repair of plantar sensory loss caused by extensive nerve gaps or high-level lesions of the posterior tibial nerve. Two cases in which this technique was used are described. The surgical technique is relatively easy, with a short operating time, rapid nerve regeneration after surgery, accurate sensory recovery, and minimal donor-site morbidity with sensory loss only on the first web space of the foot. PMID:14634907

Koshima, Isao; Nanba, Yuzaburo; Tsutsui, Tetsuya; Takahashi, Yoshio



Airway sensory nerves: a burning issue in asthma?  

PubMed Central

Asthmatic subjects cough and bronchoconstrict to various agents known to stimulate sensory nerves. A population of sensory nerves, the C fibres, contain the neuropeptides substance P, neurokinin A (NKA), and calcitonin gene-related peptide (CGRP). Capsaicin, the principal ingredient of hot peppers, selectively stimulates C fibre afferents resulting in the release of these proinflammatory peptides. An upregulation in the function of sensory nerves may lead to augmented afferent and efferent function which, in asthma, could contribute to bronchial hyper-responsiveness, inflammation, and remodelling of the airway wall. Drugs specifically designed to attenuate the function of airway sensory nerves may prove useful in the treatment of asthma. Images

Spina, D



Transient receptor potential TRPA1 channel desensitization in sensory neurons is agonist dependent and regulated by TRPV1-directed internalization  

PubMed Central

The pharmacological desensitization of receptors is a fundamental mechanism for regulating the activity of neuronal systems. The TRPA1 channel plays a key role in the processing of noxious information and can undergo functional desensitization by unknown mechanisms. Here we show that TRPA1 is desensitized by homologous (mustard oil; a TRPA1 agonist) and heterologous (capsaicin; a TRPV1 agonist) agonists via Ca2+-independent and Ca2+-dependent pathways, respectively, in sensory neurons. The pharmacological desensitization of TRPA1 by capsaicin and mustard oil is not influenced by activation of protein phosphatase 2B. However, it is regulated by phosphatidylinositol-4,5-bisphosphate depletion after capsaicin, but not mustard oil, application. Using a biosensor, we establish that capsaicin, unlike mustard oil, consistently activates phospholipase C in sensory neurons. We next demonstrate that TRPA1 desensitization is regulated by TRPV1, and it appears that mustard oil-induced TRPA1 internalization is prevented by coexpression with TRPV1 in a heterologous expression system and in sensory neurons. In conclusion, we propose novel mechanisms whereby TRPA1 activity undergoes pharmacological desensitization through multiple cellular pathways that are agonist dependent and modulated by TRPV1.

Akopian, Armen N; Ruparel, Nikita B; Jeske, Nathaniel A; Hargreaves, Kenneth M



Parkinson disease affects peripheral sensory nerves in the pharynx.  


Dysphagia is very common in patients with Parkinson disease (PD) and often leads to aspiration pneumonia, the most common cause of death in PD. Current therapies are largely ineffective for dysphagia. Because pharyngeal sensation normally triggers the swallowing reflex, we examined pharyngeal sensory nerves in PD patients for Lewy pathology.Sensory nerves supplying the pharynx were excised from autopsied pharynges obtained from patients with clinically diagnosed and neuropathologically confirmed PD (n = 10) and healthy age-matched controls (n = 4). We examined the glossopharyngeal nerve (cranial nerve IX), the pharyngeal sensory branch of the vagus nerve (PSB-X), and the internal superior laryngeal nerve (ISLN) innervating the laryngopharynx. Immunohistochemistry for phosphorylated ?-synuclein was used to detect Lewy pathology. Axonal ?-synuclein aggregates in the pharyngeal sensory nerves were identified in all of the PD subjects but not in the controls. The density of ?-synuclein-positive lesions was greater in PD patients with dysphagia versus those without dysphagia. In addition, ?-synuclein-immunoreactive nerve fibers in the ISLN were much more abundant than those in cranial nerve IX and PSB-X. These findings suggest that pharyngeal sensory nerves are directly affected by pathologic processes in PD. These abnormalities may decrease pharyngeal sensation, thereby impairing swallowing and airway protective reflexes and contributing to dysphagia and aspiration. PMID:23771215

Mu, Liancai; Sobotka, Stanislaw; Chen, Jingming; Su, Hungxi; Sanders, Ira; Nyirenda, Themba; Adler, Charles H; Shill, Holly A; Caviness, John N; Samanta, Johan E; Sue, Lucia I; Beach, Thomas G



Sensory nerve terminal mitochondrial dysfunction activates airway sensory nerves via transient receptor potential (TRP) channels.  


Mitochondrial dysfunction and subsequent oxidative stress has been reported for a variety of cell types in inflammatory diseases. Given the abundance of mitochondria at the peripheral terminals of sensory nerves and the sensitivity of transient receptor potential (TRP) ankyrin 1 (A1) and TRP vanilloid 1 (V1) to reactive oxygen species (ROS) and their downstream products of lipid peroxidation, we investigated the effect of nerve terminal mitochondrial dysfunction on airway sensory nerve excitability. Here we show that mitochondrial dysfunction evoked by acute treatment with antimycin A (mitochondrial complex III Qi site inhibitor) preferentially activated TRPA1-expressing "nociceptor-like" mouse bronchopulmonary C-fibers. Action potential discharge was reduced by the TRPA1 antagonist HC-030031. Inhibition of TRPV1 further reduced C-fiber activation. In mouse dissociated vagal neurons, antimycin A induced Ca(2+) influx that was significantly reduced by pharmacological inhibition or genetic knockout of either TRPA1 or TRPV1. Inhibition of both TRPA1 and TRPV1 was required to abolish antimycin A-induced Ca(2+) influx in vagal neurons. Using an HEK293 cell expression system, antimycin A induced concentration-dependent activation of both hTRPA1 and hTRPV1 but failed to activate nontransfected cells. Myxothiazol (complex III Qo site inhibitor) inhibited antimycin A-induced TRPA1 activation, as did the reducing agent dithiothreitol. Scavenging of both superoxide and hydrogen peroxide inhibited TRPA1 activation following mitochondrial modulation. In conclusion, we present evidence that acute mitochondrial dysfunction activates airway sensory nerves preferentially via TRPA1 through the actions of mitochondrially-derived ROS. This represents a novel mechanism by which inflammation may be transduced into nociceptive electrical signaling. PMID:23444014

Nesuashvili, Lika; Hadley, Stephen H; Bahia, Parmvir K; Taylor-Clark, Thomas E



Peripheral modification of sensory nerve responses after cross-regeneration  

PubMed Central

1. Chemical responses of skin and tongue, recorded in vivo from intact and self-regenerated cutaneous or lingual nerves, were compared to responses from cutaneous nerves cross-united with distal stumps of lingual nerves. Cross-innervated tongue grafts were also studied. 2. In contrast to normal tongue—nerve preparations, skin preparations usually showed responses to chemical stimulation with longer latency, higher threshold, and less variation of temporal pattern with diverse stimuli. These characteristics were similar when the nerve, having been cut, had regenerated. 3. On chemical stimulation of the tongue, cutaneous nerves cross-innervating the tongue often yielded records which were `gustatory' by all criteria. Some responses with low threshold and short latency were also obtained from dorsal cutaneous nerves innervating tongue grafts. 4. Thus, cutaneous nerves can serve the same role as gustatory nerves. The functional characteristics of these sensory neurones are not predetermined and must depend on the environment of the nerve endings.

Robbins, N.



Spinally elicited peripheral nerve responses are sensory rather than motor  

Microsoft Academic Search

Objectives: Spinally elicited peripheral nerve responses, commonly called neurogenic motor evoked potentials (NMEPs), are widely used to monitor spinal cord motor function during surgery. However, numerous evidence suggests that these responses are primarily sensory rather than motor. The collision technique was utilized to address this issue.Methods: Collision studies were performed in 7 patients during surgery. An ascending volley of sensory

J. R Toleikis; J. P Skelly; A. O Carlvin; J. K Burkus



Surgical anatomy of sensory portion of superficial fibular nerve for harvesting nerve grafts from fetuses.  


The use of superficial fibular nerve (Sfn) as a potential donor nerve in nerve grafting has been introduced. The limited availability of donor nerves has paved the way for nerve allografting. We studied the sensory portion of Sfn in 60 limbs from 30 fetuses. Three distinct patterns of the nerve were designated as Types 1, 2, and 3 by us. Type 1 (66.67%) comprised Sfn piercing fascia cruris then branching into Mdn and Idn. Type 2 (21.67%) was a pattern where Sfn penetrated deep fascia then continued undivided over the dorsum of foot. Type 3 (11.67%) was where Mdn and Idn penetrated deep fascia independently. The study provided quantitative measurement data of the sensory portion of Sfn and its branching nerves with respect to osseous landmarks like the head of fibula and the malleoli. Such data may be of help in defining nerve segments suitable for harvesting in nerve grafts from fetuses. PMID:20564350

Wahee, Pratima; Aggarwal, Anjali; Harjeet, K; Sahni, Daisy



The effects of extreme cold on sensory nerves.  

PubMed Central

The effects of extreme cold on sensory nerves are discussed and a clinical application of these effects is proposed. The structural changes observed following the freezing of sensory nerves in the rat are described and correlated with the clinical results in patients with chronic facial pain treated by cryogenic peripheral nerve blockade. It is suggested that this technique offers features which are not shown by any other method for interrupting peripheral pain pathways and provides a useful alternative to existing methods of treatment for chronic pain. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7

Barnard, D.



A Prospective Clinical Evaluation of Biodegradable Neurolac Nerve Guides for Sensory Nerve Repair in the Hand  

Microsoft Academic Search

Purpose: Our purpose was to study the recovery of sensory nerve function after treatment of traumatic peripheral nerve lesions with a biodegradable poly(DL-lactide--caprolactone) Neurolac nerve guide (Polyganics B.V., Groningen, the Netherlands) versus the current standard reconstruc- tion techniques. Methods: Thirty patients with 34 nerve lesions were included in this randomized, multicenter trial. Results: Both groups were comparable considering their demographics.

Mariëtta J. O. E. Bertleff; Marcel F. Meek; Jean-Phillipe A. Nicolai



Age-related changes in sympathetic modulation of sensory nerve activity in rat skin  

Microsoft Academic Search

Objectives: Sensory nerves play an important role in mediating neurogenic inflammation and subsequent tissue healing. A decrease in sensory nerve function with increasing age has been reported to correlate with poor tissue healing. Sympathetic nerves are known to modulate sensory nerve function, and changes in this modulation could also have important implications with ageing. The aims of this study were

M. Merhi; R. D. Helme; Z. Khalil



Autonomic and sensory nerve dysfunction in primary biliary cirrhosis  

Microsoft Academic Search

AIM: Cardiovascular autonomic and peripheral sensory neuropathy is a known complication of chronic alcoholic and non-alcoholic liver diseases. We aimed to assess the prevalence and risk factors for peripheral sensory nerve and autonomic dysfunction using sensitive methods in patients with primary biliary cirrhosis (PBC). METHODS: Twenty-four AMA M2 positive female patients with clinical, biochemical and histological evidence of PBC and

Katalin Keresztes; Ildikó Istenes; Aniko Folhoffer; Peter L Lakatos; Andrea Horvath; Timea Csak; Peter Varga; Peter Kempler; Ferenc Szalay; Lakatos PL


Sensory nerve action potentials and sensory perception in women with arthritis of the hand  

PubMed Central

Background Arthritis of the hand can limit a person’s ability to perform daily activities. Whether or not sensory deficits contribute to the disability in this population remains unknown. The primary purpose of this study was to determine if women with osteoarthritis (OA) or rheumatoid arthritis (RA) of the hand have sensory impairments. Methods Sensory function in the dominant hand of women with hand OA or RA and healthy women was evaluated by measuring sensory nerve action potentials (SNAPs) from the median, ulnar and radial nerves, sensory mapping (SM), and vibratory and current perception thresholds (VPT and CPT, respectively) of the second and fifth digits. Results All SNAP amplitudes were significantly lower for the hand OA and hand RA groups compared with the healthy group (p?sensory fibers in the median, ulnar and radial nerves. Less apparent were losses in conduction speed or sensory perception.



Sensory nerve impairment following mandibular third molar surgery  

Microsoft Academic Search

Purpose: This prospective study reports the rate and factors influencing sensory impairment of the inferior alveolar and lingual nerves after the removal of impacted mandibular third molars under local anesthesia. Patients and Methods: There were 741 patients with 741 mandibular third molars removed under local anesthesia during a 3-year period from 1994 to 1997. Standardized data collection included the patient's

Anwar B Bataineh



Central reorganization of sensory pathways following peripheral nerve regeneration in fetal monkeys  

Microsoft Academic Search

TRANSECTION of a sensory nerve in adults results in profound abnormalities in sensory perception, even if the severed nerve is surgically repaired to facilitate accurate nerve regeneration. In marked contrast, fewer perceptual errors follow nerve transection and surgical repair in children1-3. The basis for this superior recovery in children was unknown. Here we show that there is little or no

Sherre L. Florence; Neeraj Jain; Marcie W. Pospichal; Pam D. Beck; D. Lewis Sly; Jon H. Kaas



Degeneration and regeneration of cutaneous sensory nerve formations.  


Auxiliary structures of the cutaneous sensory nerve formations (SNF) are dependent on sensory innervation during their critical period of development. Denervation of mature cutaneous corpuscles results in survival of the terminal Schwann cells and the capsular structures which are probably responsible for successful reinnervation of the cutaneous SNF. In addition, the basal lamina tubes of Schwann cells are connected with the terminal Schwann cells and play an important role in the guidance of regrowing axons to their original targets. Long-lasting denervation causes atrophic changes of the terminal Schwann cells and alterations of their molecular equipment. These atrophic changes in the terminal Schwann cells may be responsible for erroneous reinnervation of cutaneous SNF. A population of the cutaneous Merkel cells surviving denervation may also serve as targets for regrowing sensory axons. The basal laminae of terminal Schwann cells are produced under control of the sensory terminals during maturation of cutaneous SNF. In adult animals, the basal laminae are capable of stimulating differentiation of migrated Schwann cells to the terminal Schwann cells without the presence of the sensory terminals. Nonspecific cholinesterase (nChE) is secreted by the terminal Schwann cells and is attached to their extracellular matrix. The synthesis of these molecules in adult animals is not influenced by the sensory terminals. However, the presence of nChE molecules is associated with living terminal Schwann cells. Fetal orthotopically grafted dorsal root ganglion (DRG) neurons have the ability to reinnervate cutaneous SNF of adult hosts. When cutaneous areas are denervated, axons from adjacent sensory nerves may extend collateral branches into this area. The capacity for such extension is dependent on: (1) type of sensory nerve ending, C and A delta fibers having significantly greater capacity than sensory axons of larger caliber; (2) age of the animal, immature animals generally showing a greater capacity for collateral sprouting; (3) the state of the adjacent axons, those already in a growth mode being more capable than "resting" ones; and (4) the regional and mechanical conditions at the site of denervation, hindpaw skin being much less extensively reinnervated by collateral fibers than that of the trunk. PMID:8807619

Dubový, P; Aldskogius, H



Lack of topographical specificity in sensory nerve regeneration through muscle grafts in rats.  


Regenerating sensory axons of each receptor class make new connections with similar denervated receptors. This study investigates to what extent these axons return to their original receptive field. The lateral cutaneous nerves of the thigh in rats were divided and allowed to regenerate across a 6 mm. gap interposed with frozen and thawed muscle graft towards their original distal nerve stump and a "foreign" sensory nerve, the saphenous nerve. 16 weeks later, myelinated axon counts of 26 pairs of distal nerves showed no preferential growth towards the original receptive field. Lack of topographic specificity during sensory nerve regeneration may explain the faulty localisation of sensation after nerve repair in clinical practice. Following sensory nerve regeneration, the somatosensory cortex receives accurate afferent information but from disparate skin sites; this probably alters the relationship of overlapping sensory fields and may be the cause of distorted pattern recognition. PMID:1791364

Rath, S; Green, C J



Sensory re-education after nerve repair: aspects of timing.  


The recovery of functional sensibility after nerve transection and repair is often disappointing. Here we address the timing of sensory re-education that aims at re-learning and modulating the changed sensory code from the hand after such an injury. Such training utilises the capacity for cortical functional re-modelling which characterises the young as well as the adult brain. Sensory re-education is traditionally not introduced until there is reinnervation in the hand, and such a late onset of training may be one explanatory factor for the poor functional results after nerve repair. Since functional reorganisation changes of the cortex occurring after changes in peripheral input are very fast processes, we suggest that this specific intervention should be introduced very early in the rehabilitation phase--already in the initial phase after nerve repair when no axons have yet arrived to the asensible hand. The goal is to avoid, minimise and modulate the central functional re-organisation which follows the de-afferentiation associated with nerve injury and repair. This early intervention can be done with the use of artificial sensibility the first post-operative day. According to this technique, based on sense substitution and utilising the multimodal capacity of the brain, miniature microphones on the fingertips of the asensible hand pick up the friction sound generated by active touch. The vibro-tactile signals are stereophonically transposed to vibro-acoustic signals, thereby providing an alternate feed-back which hypothetically helps to maintain or re-establish the cortical hand map. PMID:15083384

Rosén, B; Lundborg, G



Bilateral isolated cut of sensory branch of radial nerve.  


Bilateral injuries of the sensory branch of the radial nerve (SBRN) usually occur as a result of tight-handcuff neuropathy. In this case we aimed to present bilateral isolated cut of SBRN resulting an injury mechanism that has not been reported in the literature previously. A male twenty-four years old, a worker in a glass factory, presented to our clinic. The dorsolateral skin of his wrists were cut by breaking of the glass as a result of occupational accident and was primarily sutured in a healthcare center. The patient sought additional care after a month because of lingering numbness and pain, and surgery was planned. During surgery, scar tissue and neuroma at the cut ends of SBRN were excised, and bilateral SBRN cuts were repaired. Four weeks after operation, mild sensory deficit on the dorsal side of bilateral thumbs, and left first web space and flexion limitation on the right wrist were detected. At the 3rd month postoperative, right wrist joint range of motion was full, and sensory deficits, and hyperesthesia were decreased. The SBRN elicits the sensory innervation of the thumb dorsum and its injury does not cause important functional deficit. However because of susceptibility of SBRN to develop painful neuroma, diagnosis, treatment and follow up of isolated SBRN injury would be worthwhile for prevention of possible painful neuropathy disturbing quality of life. PMID:23599208

Akkaya, Nuray; Özcan, Hakan Ramazan; Gökalan Kara, Inci; Sahin, Füsun



Uses of Skin Biopsy for Sensory and Autonomic Nerve Assessment  

PubMed Central

Skin biopsy is a valuable diagnostic tool for small-fiber-predominant neuropathy by the quantification of intra-epidermal 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.

Myers, M. Iliza; Peltier, Amanda C.



Uses of skin biopsy for sensory and autonomic nerve assessment.  


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

Myers, M Iliza; Peltier, Amanda C



Sensory electroneurographic parameters and clinical recovery of sensibility in sutured human nerves  

Microsoft Academic Search

A total of 37 patients with traumatic transection of median or ulnar nerves at the wrist (total 41 nerves) were examined clinically and electrophysiologically 4–59 months after primary or secondary suture or grafting. There was a significant increase of cumulative amplitude with the time after suture, whereas maximum sensory nerve conduction velocity and maximum amplitude of nerve action potentials did

W. Tackmann; J. Brennwald; H. Nigst



Development of purinergic sensitivity in sensory neurons after peripheral nerve injury in the rat  

Microsoft Academic Search

Purinoceptors are present in the cell bodies as well as in both peripheral and central terminals of many sensory neurons, where they may play a role in sensory transmission, including pain. After peripheral nerve injury at the spinal nerve level, some axotomized afferent neurons develop ongoing discharges (ectopic discharges) that originate in the dorsal root ganglion (DRG). In the present

Junli Zhou; Kyungsoon Chung; Jin Mo Chung



Nerve supply to the inner sensory cells in a human cochlea.  


A choclear apical turn taken from a 66-year-old woman showed an area with marked decrease in number of the inner sensory cells. After observation by scanning electron microscope, the same specimen was thin-sectioned tangentially to the osseous spiral lamina. Numbers of myelinated nerve fibers were counted and the thickness of the fiber was measured by computed measuring equipment. Compared to the area with inner sensory cells intact, the area without inner sensory cells showed a 70% decrease in number of myelinated fibers. These degenerated fibers might have had intimate relationship with the inner sensory cells, probably being the afferent nerve supply to the inner sensory cells. PMID:475658

Hoshino, T; Kodama, A



Substance P enhances cholinergic receptor desensitization in a clonal nerve cell line.  

PubMed Central

Substance P inhibits carbamylcholine-induced 22Na+ uptake in the clonal cell line PC12. This inhibition is noncompetitive with agonist but competitive with Na+. Octahydrohistrionicotoxin (H8-HTX) also exhibits this same pattern of inhibition. Moreover, both substance P and H8-HTX are very effective in enhancing agonist-induced receptor desensitization. Local anesthetics, such as QX222, also cause inhibition that is competitive with Na+, but they have only marginal effects on desensitization. Because substance P and H8-HTX cannot by themselves cause desensitization, their action is dependent on and synergistic with the action of agonist. Furthermore, substance P and H8-HTX do not appear to compete for the same site as QX222, which is thought to bind to the ion channel. Finally, substance P can stabilize the desensitized state of the receptor even when added subsequent to the actual desensitization and removal of agonist. Thus, substance P does not require open ion channels for binding and may modulate the activity of the receptor-ionophore complex by binding to a distinct regulatory site.

Stallcup, W B; Patrick, J



Photostimulation of sensory neurons of the rat vagus nerve  

NASA Astrophysics Data System (ADS)

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 (Ca2+), into the cell to cause membrane depolarization. Therefore, to monitor TRPV1 activation consequent to photostimulation, we used fura-2, a fluorescent Ca2+ indicator, to monitor the rise in intracellular Ca2+ concentration ([Ca2+]i). Brief trains of 2-msec IR pulses activated TRPV1 rapidly and reversibly, as evidenced by transient rises in [Ca2+]i (referred to as Ca2+ transients). Consistent with the Ca2+ transients arising from influx of Ca2+, identical photostimulation failed to evoke Ca2+ responses in the absence of extracellular Ca2+. Furthermore, the photo-induced Ca2+ 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.

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



Immunohistochemical localization of laminin and type IV collagen in human cutaneous sensory nerve formations  

Microsoft Academic Search

We used immunohistochemical techniques and monoclonal antibodies to localize two basement membrane components (laminin and type IV collagen) in the nerves and sensory nerve formations, or corpuscles, supplying human digital skin. Furthermore, neurofilament proteins, S-100 protein and epithelial membrane antigen were studied in parallel. In dermal nerve trunks, immunostaining for laminin and type IV collagen was found to be co-localized

J. A. Vega; I. Esteban; F. J. Naves; M. E. Valle; L. Malinovsky



Changes in sensory activity of ocular surface sensory nerves during allergic keratoconjunctivitis.  


Peripheral neural mechanisms underlying the sensations of irritation, discomfort, and itch accompanying the eye allergic response have not been hitherto analyzed. We explored this question recording the changes in the electrical activity of corneoconjunctival sensory nerve fibers of the guinea pig after an ocular allergic challenge. Sensitization was produced by i.p. ovalbumin followed by repeated application in the eye of 10% ovalbumin on days 14 to 18. Blinking and tearing rate were measured. Spontaneous and stimulus-evoked (mechanical, thermal, chemical) impulse activity was recorded from mechanonociceptor, polymodal nociceptor and cold corneoscleral sensory afferent fibers. After a single (day 14) or repeated daily exposures to the allergen during the following 3 to 4days, tearing and blinking rate increased significantly. Also, sensitization was observed in mechanonociceptors (transient reduction of mechanical threshold only on day 14) and in polymodal nociceptors (sustained enhancement of the impulse response to acidic stimulation). In contrast, cold thermoreceptors showed a significant decrease in basal ongoing activity and in the response to cooling. Treatment with the TRPV1 and TRPA1 blockers capsazepine and HC-030031 reversed the augmented blinking. Only capsazepine attenuated tearing rate increase and sensitization of the polymodal nociceptors response to CO2. Capsazepine also prevented the decrease in cold thermoreceptor activity caused by the allergic challenge. We conclude that changes in nerve impulse activity accompanying the ocular allergic response, primarily mediated by activation of nociceptor's TRPV1 and to a lesser degree by activation of TRPA1 channels, explain the eye discomfort sensations accompanying allergic episodes. PMID:23867735

Acosta, M Carmen; Luna, Carolina; Quirce, Susana; Belmonte, Carlos; Gallar, Juana



Sensory Nerves in Adult Rats Regenerate and Restore Sensory Function to the Skin Independently of Endogenous NGF  

Microsoft Academic Search

We have investigated the possible roles of NGF, and of im- pulse activity, in the regeneration of sensory nerves. Un- expectedly, the ability of crushed axons to regrow and to restore functional recovery of three sensory modalities in adult rat skin (Aa-mediated touch, A&mediated mechano- nociception, and C-fiber-mediated heat nociception) was totally unaffected by anti-NGF treatment. This finding ap- plied

Jack Diamond; Anne Foerster; Michael Holmes; Michael Coughlin



Sensory handedness is not reflected in cortical responses after basic nerve stimulation: a MEG study.  


Motor dominance is well established, but sensory dominance is much less clear. We therefore studied the cortical evoked magnetic fields using magnetoencephalography (MEG) in a group of 20 healthy right handed subjects in order to examine whether standard electrical stimulation of the median and ulnar nerve demonstrated sensory lateralization. The global field power (GFP) curves, as an indication of cortical activation, did not depict sensory lateralization to the dominant left hemisphere. Comparison of the M20, M30, and M70 peak latencies and GFP values exhibited no statistical differences between the hemispheres, indicating no sensory hemispherical dominance at these latencies for each nerve. Field maps at these latencies presented a first and second polarity reversal for both median and ulnar stimulation. Spatial dipole position parameters did not reveal statistical left-right differences at the M20, M30 and M70 peaks for both nerves. Neither did the dipolar strengths at M20, M30 and M70 show a statistical left-right difference for both nerves. Finally, the Laterality Indices of the M20, M30 and M70 strengths did not indicate complete lateralization to one of the hemispheres. After electrical median and ulnar nerve stimulation no evidence was found for sensory hand dominance in brain responses of either hand, as measured by MEG. The results can provide a new assessment of patients with sensory dysfunctions or perceptual distortion when sensory dominance occurs way beyond the estimated norm. PMID:22080222

Chen, Andrew C N; Theuvenet, Peter J; de Munck, Jan C; Peters, Maria J; van Ree, Jan M; Lopes da Silva, Fernando L



Sensory nerve findings by tactile stimulation of median and ulnar nerves in healthy subjects of different ages.  


We studied orthodromic sensory conduction velocity along the distal and proximal segments of the median and ulnar nerves by tactile stimulation of the distal phalanx of the 3rd and 5th digits in 44 healthy subjects divided into 2 age groups: from 16 to 35 years and from 63 to 81 years. In the same nerves, we used selective electrical stimulation of the corresponding digital nerves to obtain sensory potentials. In both groups, responses to tactile stimuli had a longer latency and smaller amplitude than those to electrical stimulation, and they were distributed in a series of 6-7 main deflections, apparently regardless of whether the recording site was distal or proximal. Moreover, irrespective of the nerve and of subject age, conduction velocity along both the digit-wrist and the wrist-elbow nerve segments was significantly slower with tactile stimuli than with electrical stimuli. However, independently of the stimulus used, conduction velocity along the proximal nerve segment was significantly faster than that measured along the digit-wrist nerve segment. In both the median and ulnar nerves, maximum potential amplitude, cumulative area and conduction velocity were significantly reduced in the older age group. This finding could reflect the smaller number of Meissner's corpuscles in older subjects, and the loss of large nerve fibres in individuals over 60. PMID:7507425

Caruso, G; Nilsson, J; Crisci, C; Nolano, M; Massini, R; Lullo, F



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

Microsoft Academic Search

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.

Paul D. Marasco; Aimee E. Schultz; Todd A. Kuiken



Lack of Topographical Specificity in Sensory Nerve Regeneration through Muscle Grafts in Rats  

Microsoft Academic Search

Regenerating sensory axons of each receptor class make new connections with similar denervated receptors. This study investigates to what extent these axons return to their original receptive field. The lateral cutaneous nerves of the thigh in rats were divided and allowed to regenerate across a 6 mm. gap interposed with frozen and thawed muscle graft towards their original distal nerve




Distribution of sensory nerve endings in the labial mucosa of the mouse.  


The distribution of sensory nerve endings in the labial mucosa of the mouse was investigated by the vital methylene blue staining method. Encapsulated corpuscles were distributed uniformly throughout the mucosa, whereas bush-like nerve endings were localized in the area along the median line where the mucosal epithelium showed a considerable thickness. The number of the encapsulated corpuscles per individual was 72-133, and that of the bush-like nerve endings was 131-248. PMID:7336425

Yamamoto, T; Sakada, S



Recovery of sensory nerve fibres after surgical decompression in lumbar radiculopathy: use of quantitative sensory testing in the exploration of different populations of nerve fibres  

Microsoft Academic Search

Thirty nine patients with unilateral lumbar nerve root compression at one level were examined with quantitative sensory testing immediately before microdiscectomy and at six weeks, four months, and 12 months after surgery. Twenty one healthy volounteers were used as controls. The patients were classified as having a good or a poor result at the one year follow up. The improvement

Ř P Nygaard; R Kloster; S I Mellgren




PubMed Central

Breast cancer metastasis to bone is frequently accompanied by pain. What remains unclear is why this pain tends to become more severe and difficult to control with disease progression. Here we test the hypothesis that with disease progression sensory nerve fibers that innervate the breast cancer bearing bone undergo a pathological sprouting and reorganization, which in other non-malignant pathologies has been shown to generate and maintain chronic pain. Injection of human breast cancer cells (MDA-MB-231-BO) into the femoral intramedullary space of female athymic nude mice induces sprouting of calcitonin gene-related peptide (CGRP+) sensory nerve fibers. Nearly all CGRP+ nerve fibers that undergo sprouting also co-express tropomyosin receptor kinase A (TrkA+) and growth associated protein-43 (GAP43+). This ectopic sprouting occurs in periosteal sensory nerve fibers that are in close proximity to breast cancer cells, tumor-associated stromal cells and remodeled cortical bone. Therapeutic treatment with an antibody that sequesters nerve growth factor (NGF), administered when the pain and bone remodeling were first observed, blocks this ectopic sprouting and attenuates cancer pain. The present data suggest that the breast cancer cells and tumor-associated stromal cells express and release NGF, which drives bone pain and the pathological reorganization of nearby CGRP+ / TrkA+ / GAP43+ sensory nerve fibers.

Bloom, Aaron P.; Jimenez-Andrade, Juan M.; Taylor, Reid N.; Castaneda-Corral, Gabriela; Kaczmarska, Magdalena J.; Freeman, Katie T.; Coughlin, Kathleen A.; Ghilardi, Joseph R.; Kuskowski, Michael A.; Mantyh, Patrick W.



Gait phase information provided by sensory nerve activity during walking: applicability as state controller feedback for FES  

Microsoft Academic Search

In this study, we extracted gait-phase information from natural sensory nerve signals of primarily cutaneous origin recorded in the forelimbs of cats during walking on a motorized treadmill. Nerve signals were recorded in seven cats using nerve cuff or patch electrodes chronically implanted on the median, ulnar, and\\/or radial nerves. Features in the electroneurograms that were related to paw contact

K. D. Strange; J. A. Hoffer; J. B. Wagenaar



Morphology and nanomechanics of sensory neurons growth cones following peripheral nerve injury.  


A prior peripheral nerve injury in vivo, promotes a rapid elongated mode of sensory neurons neurite regrowth in vitro. This in vitro model of conditioned axotomy allows analysis of the cellular and molecular mechanisms leading to an improved neurite re-growth. Our differential interference contrast microscopy and immunocytochemistry results show that conditioned axotomy, induced by sciatic nerve injury, did not increase somatic size of adult lumbar sensory neurons from mice dorsal root ganglia sensory neurons but promoted the appearance of larger neurites and growth cones. Using atomic force microscopy on live neurons, we investigated whether membrane mechanical properties of growth cones of axotomized neurons were modified following sciatic nerve injury. Our data revealed that neurons having a regenerative growth were characterized by softer growth cones, compared to control neurons. The increase of the growth cone membrane elasticity suggests a modification in the ratio and the inner framework of the main structural proteins. PMID:23418549

Martin, Marta; Benzina, Ouafa; Szabo, Vivien; Végh, Attila-Gergely; Lucas, Olivier; Cloitre, Thierry; Scamps, Frédérique; Gergely, Csilla



Reinnervation of Smooth and Striated Muscle by Sensory Nerve Fibers.  

National Technical Information Service (NTIS)

The normal postganglionic adrenergic innervation of the nictitating membrane of the cat was replaced by sensory fibers pertaining to the central root of the vagal nodose ganglion. Under these conditions stimulation of the vagal trunk resulted in a contrac...

C. L. Vera J. V. Luco



Intraepithelial Vagal Sensory Nerve Terminals in Rat Pulmonary Neuroepithelial Bodies Express P2X 3 Receptors  

Microsoft Academic Search

The neurotransmitters\\/modulators involved in the interaction between pulmonary neuroepithelial bodies (NEBs) and the va- gal sensory component of their innervation have not yet been elucidated. Because P2X 3 purinoreceptors are known to be strongly expressed in peripheral sensory neurons, the aim of the present study was to examine the localization of nerve endings expressing P2X 3 purinoreceptors in the rat

Inge Brouns; Dirk Adriaensen; Geoff Burnstock; Jean-Pierre Timmermans


Intrafascicular stimulation of monkey arm nerves evokes coordinated grasp and sensory responses.  


High-count microelectrode arrays implanted in peripheral nerves could restore motor function after spinal cord injury or sensory function after limb loss. In this study, we implanted Utah Slanted Electrode Arrays (USEAs) intrafascicularly at the elbow or shoulder in arm nerves of rhesus monkeys (n = 4) under isoflurane anesthesia. Input-output curves indicated that pulse-width-modulated single-electrode stimulation in each arm nerve could recruit single muscles with little or no recruitment of other muscles. Stimulus trains evoked specific, natural, hand movements, which could be combined via multielectrode stimulation to elicit coordinated power or pinch grasp. Stimulation also elicited short-latency evoked potentials (EPs) in primary somatosensory cortex, which might be used to provide sensory feedback from a prosthetic limb. These results demonstrate a high-resolution, high-channel-count interface to the peripheral nervous system for restoring hand function after neural injury or disruption or for examining nerve structure. PMID:23076108

Ledbetter, Noah M; Ethier, Christian; Oby, Emily R; Hiatt, Scott D; Wilder, Andrew M; Ko, Jason H; Agnew, Sonya P; Miller, Lee E; Clark, Gregory A



Effect of helium-neon laser irradiation on peripheral sensory nerve latency  

SciTech Connect

The purpose of this randomized, double-blind study was to determine the effect of a helium-neon (He-Ne) laser on latency of peripheral sensory nerve. Forty healthy subjects with no history of right upper extremity pathological conditions were assigned to either a Laser or a Placebo Group. Six 1-cm2 blocks along a 12-cm segment of the subjects' right superficial radial nerve received 20-second applications of either the He-Ne laser or a placebo. We assessed differences between pretest and posttest latencies with t tests for correlated and independent samples. The Laser Group showed a statistically significant increase in latency that corresponded to a decrease in sensory nerve conduction velocity. Short-duration He-Ne laser application significantly increased the distal latency of the superficial radial nerve. This finding provides information about the mechanism of the reported pain-relieving effect of the He-Ne laser.

Snyder-Mackler, L.; Bork, C.E.



Recording sensory and motor information from peripheral nerves with Utah Slanted Electrode Arrays  

Microsoft Academic Search

Recording and stimulation via high-count penetrating microelectrode arrays implanted in peripheral nerves may help restore precise motor and sensory function after nervous system damage or disease. Although previous work has demonstrated safety and relatively successful stimulation for long-term implants of 100-electrode Utah Slanted Electrode Arrays (USEAs) in feline sciatic nerve [1], two major remaining challenges were 1) to maintain viable

Gregory A. Clark; Noah M. Ledbetter; David J. Warren; Reid R. Harrison



Sensory nerve conduction and nociception in the equine lower forelimb during perineural bupivacaine infusion along the palmar nerves  

PubMed Central

The purpose of this investigation was to study lateral palmar nerve (LPN) and medial palmar nerve (MPN) morphology and determine nociception and sensory nerve conduction velocity (SNCV) following placement of continuous peripheral nerve block (CPNB) catheters along LPN and MPN with subsequent bupivacaine (BUP) infusion. Myelinated nerve fiber distribution in LPN and MPN was examined after harvesting nerve specimens in 3 anesthetized horses and processing them for morphometric analysis. In 5 sedated horses, CPNB catheters were placed along each PN in both forelimbs. Horses then received in one forelimb 3 mL 0.125% BUP containing epinephrine 1:200 000 and 0.04% NaHCO3 per catheter site followed by 2 mL/h infusion over a 6-day period, while in the other forelimb equal amounts of saline (SAL) solution were administered. The hoof withdrawal response (HWR) threshold during pressure loading of the area above the dorsal coronary band was determined daily in both forelimbs. On day 6 SNCV was measured under general anesthesia of horses in each limb’s LPN and MPN to detect nerve injury, followed by CPNB catheter removal. The SNCV was also recorded in 2 anesthetized non-instrumented horses (sham controls). In both LPN and MPN myelinated fiber distributions were bimodal. The fraction of large fibers (>7 ?m) was greater in the MPN than LPN (P < 0.05). Presence of CPNB catheters and SAL administration did neither affect measured HWR thresholds nor SNCVs, whereas BUP infusion suppressed HWRs. In conclusion, CPNB with 0.125% BUP provides pronounced analgesia by inhibiting sensory nerve conduction in the distal equine forelimb.

Zarucco, Laura; Driessen, Bernd; Scandella, Massimiliano; Cozzi, Francesca; Cantile, Carlo



Artifact-free sensory nerve signals obtained from cuff electrodes during functional electrical stimulation of nearby muscles  

Microsoft Academic Search

Restoration of the voluntary use of paralyzed limbs using functional neuromuscular stimulation (FNS) is limited by complex muscle properties and unpredictable load behaviors; closed-loop control of FNS would improve performance but requires reliable sensory feedback modalities. Sensory nerve signals recorded by cuff electrodes provide accurate information about forces acting on the skin in anesthetized animals; however, nerve cuff signals are

Morten K. Haugland; J. Andy Hoffer



Restoration of sensibility in irreparable ulnar and median nerve lesions with use of sensory nerve transfer: Long-term follow-up of 20 cases  

Microsoft Academic Search

A prospective study was conducted to evaluate patient outcomes following sensory nerve transfer. Twenty patients with irreparable ulnar or median nerve lesions underwent the procedure. Nerve involvement was bilateral in 5 cases. The mean age of the patients at the time of surgery was 29 years. The mean paralysis time and the average length of follow-up were 59 and 78

Türker Özkan; Ka?an Özer; Ayan Gülgönen



On the relationship between nociceptive evoked potentials and intraepidermal nerve fiber density in painful sensory polyneuropathies  

Microsoft Academic Search

This study analyzed the relationship between the density of intraepidermal nerve fibers (IENF) and the characteristics of either nociceptive laser-evoked potentials (LEPs) or contact heat-evoked potentials (CHEPs) in patients with painful sensory polyneuropathy with the aim to determine which parameters of LEPs and CHEPs more reliably reflect IENF loss. A total of 96 patients and 35 healthy volunteers took part

Jordi Casanova-Molla; Josep Maria Grau-Junyent; Merche Morales; Josep Valls-Solé



Bronchial hyperresponsiveness induced by chronic treatment with albuterol: Role of sensory nerves  

Microsoft Academic Search

Background: It has recently been suggested that regular treatment with racemic ?2-adrenoceptor agonists might result in bronchial hyperresponsiveness (BHR) to a range of spasmogens, and this might be due to adverse effects of the distomer. Objective: We sought to determine whether BHR induced by means of continuous exposure to racemic and S-albuterol was mediated by sensory nerves. Methods: Naive or

Sandra Keir; Clive Page; Domenico Spina



A semi-automated analysis method of small sensory nerve fibers in human skin-biopsies  

Microsoft Academic Search

Computerized detection method (CDM) software programs have been extensively developed in the field of astronomy to process and analyze images from nearby bright stars to tiny galaxies at the edge of the Universe. These object-recognition algorithms have potentially broader applications, including the detection and quantification of cutaneous small sensory nerve fibers (SSNFs) found in the dermal and epidermal layers, and

Kazuyuki Tamura; Violet A. Mager; Lindsey A. Burnett; John H. Olson; Jeremy B. Brower; Ashley R. Casano; Debra P. Baluch; Jerome H. Targovnik; Rogier A. Windhorst; Richard M. Herman



Sensory conduction study of the infrapatellar branch of the saphenous nerve.  


Although neuropathies of the infrapatellar nerve (infrapatellar branch of the saphenous nerve, IPBSN) have been reported clinically, no electrophysiological method has been defined to evaluate IPBSN conduction. We therefore studied a total of 60 saphenous nerves and 60 IPBSNs from 36 volunteers. The IPBSN was stimulated medially with a surface electrode 2 cm below the patella. The response was recorded with a needle electrode located close to the nerve 1 cm lateral to the femoral artery in the inguinal region. Sensory nerve action potentials were obtained from each subject; mean latency of the first positive peak was 8.1 +/- 0.9 ms, conduction velocity was 54 +/- 4.4 m/s, and response amplitude was 1.3 +/- 1.1 microV. The method that we describe may be an easy and useful electrophysiological test for neuropathies of the IPBSN. PMID:17068766

Bademkiran, Fikret; Obay, Basra; Aydogdu, Ibrahim; Ertekin, Cumhur



Nerve growth factor promotes regeneration of sensory axons into adult rat spinal cord.  


Injured adult mammalian axons are unable to regenerate spontaneously in the central nervous tissue. This study investigated in two adult rat models the effects of nerve growth factor (NGF) on the capacity of central primary sensory axons to regenerate back into the spinal cord. Sensory fibers were conditioned by transection of the peripheral nerve 1 week prior to the experiment and identified by anterograde tracing with cholera toxin B subunit injected in the sciatic nerve. In the first model, a predegenerated autologous peripheral nerve graft was implanted as a bridge for the transected sensory fibers into a resection gap in the dorsal columns at the tenth thoracic (T10) spinal cord segment. Vehicle or vehicle with purified mouse or recombinant human NGF was continuously infused for 2 weeks directly into the dorsal column at T9, 3 mm from the rostral border of the nerve graft. With vehicle infusion many ascending sensory axons had grown across the nerve bridge, but essentially none had grown back into the rostral cord. In sharp contrast, NGF promoted the reentry into the denervated dorsal columns of 51% of the sensory axons that had reached the rostral level of the nerve graft. Twenty-six percent had grown 2 mm into the spinal tissue and 10% had reached the NGF-infusion site at 3 mm from the nerve graft. A few fibers were found circling around, but not beyond, the infusion site, perhaps due to the chemoattractant action of NGF. In a second model, the fourth lumbar (L4) dorsal root was crushed 2 mm from its insertion point into the spinal cord and the dorsal roots L2, L3, L5, and L6 were transected. Vehicle or vehicle with purified mouse NGF was infused for 2 weeks directly into the lumbar spinal cord, 2.5 mm rostral to the transition zone of the crushed L4 root. With vehicle, only 6% of the regenerating fibers at the transition zone had crossed the root-spinal cord barrier, but not farther than 0.5 mm into the spinal tissue. With NGF, 18% of the fibers at the transition zone were found at 0.5 mm, 9% at 1.5 mm, and 5% at 2.5 mm (the infusion site) from the transition zone. The present results demonstrate that NGF can promote the regeneration of adult sensory fibers into the otherwise nonpermissive spinal cord white matter. PMID:8690064

Oudega, M; Hagg, T



CGRP-immunoreactive sensory nerve fibers in the submandibular gland of the rat.  


Indirect immunofluorescence technique was used to study the occurrence and distribution of CGRP immunoreactivity in the submandibular gland of normal rats and after unilateral sensory and sympathetic denervations. In normal rats, CGRP-immunoreactive nerve fibers and nerve trunks were seen around or in close contact with interlobular salivary ducts as well as around small blood vessels of the gland. Occasionally, CGRP-immunoreactive nerve fibers were also detected between or around the acini of the gland. The submandibular ganglia contained CGRP-immunoreactive nerve fibers, but the ganglion cells were not immunoreactive for CGRP. The trigeminal ganglion contained a population of CGRP-immunoreactive, mainly small sized ganglion cells and nerve fibers distributed throughout the ganglion. Unilateral electrocoagulation of the trigeminal nerve caused a significant reduction in the number of immunoreactive nerve fibers in the gland, although some fibers still were present in the ipsilateral glandular tissue. Unilateral superior cervical ganglionectomy caused no detectable effect on the number of CGRP-immunoreactive nerve fibers in the gland. The present results suggest that the rat submandibular gland contains CGRP-immunoreactive nerve fibers both around blood vessels and in glandular secretory elements. Denervation experiments support the view that the majority, but perhaps not all of them originate from the trigeminal ganglion. PMID:2670843

Soinila, J; Salo, A; Uusitalo, H; Yanaihara, N; Häppölä, O



Sensory nerve conduction in branches of common interdigital nerves: a new technique for normal controls and patients with morton's neuroma.  


In this article, a new electrodiagnostic approach is described for patients with Morton's neuroma. The new method is based on the anatomic fact that the two branches of the common plantar interdigital nerves innervate the lateral side of one toe and the medial side the next one. This study included 20 normal subjects (aged 28-58 years, 10 men and 10 women) and 4 patients with Morton's neuroma (aged 44-52 years, 4 women). The branches of adjacent common plantar interdigital nerves that innerve one toe were stimulated superficially and separately with half of one toe covered with a piece of medical tape. The recordings were obtained on the posterior tibial nerve at the medial malleolus with needle electrodes. Thus, the difference in latencies of obtained sensory nerve action potentials on the posterior tibial nerve with needle electrode was measured. From normal subjects' data, it was determined that a latency difference value of above 0.17 milliseconds (mean +/- 2.5 SD) in one toe was abnormal. All of the patients with Morton's neuroma showed abnormal interlatency difference values. This new method, which we have developed, is more sensitive, simple to use, does not require extra equipment, and does not cause excessive pain. We suggest that interlatency difference between branches of the common plantar interdigital nerves is a useful and sensitive method for the diagnosis of Morton's neuroma. PMID:20479659

Uludag, Burhanettin; Tataroglu, Cengiz; Bademkiran, Fikret; Uludag, Irem Fatma; Ertekin, Cumhur



Changes induced by peripheral nerve injury in the morphology and nanomechanics of sensory neurons.  


ABSTRACT. Peripheral nerve injury in vivo promotes a regenerative growth in vitro characterized by an improved neurite regrowth. Knowledge of the conditioning injury effects on both morphology and mechanical properties of live sensory neurons could be instrumental to understand the cellular and molecular mechanisms leading to this regenerative growth. In the present study, we use differential interference contrast microscopy, fluorescence microscopy, and atomic force microscopy (AFM) to show that conditioned axotomy, induced by sciatic nerve injury, does not increase somatic size of sensory neurons from adult mice lumbar dorsal root ganglia but promotes the appearance of longer and larger neurites and growth cones. AFM on live neurons is also employed to investigate changes in morphology and membrane mechanical properties of somas of conditioned neurons following sciatic nerve injury. Mechanical analysis of the soma allows distinguishing neurons having a regenerative growth from control ones, although they show similar shapes and sizes. PMID:24165740

Benzina, Ouafa; Szabo, Vivien; Lucas, Olivier; Saab, Mari-Belle; Cloitre, Thierry; Scamps, Frédérique; Gergely, Csilla; Martin, Marta



Peripheral Nerve Damage Facilitates Functional Innervation of Brain Grafts in Adult Sensory Cortex  

NASA Astrophysics Data System (ADS)

The neuralb pathways that relay information from cutaneous receptors to the cortex provide the somatic sensory information needed for cortical function. The last sensory relay neurons in this pathway have cell bodies in the thalamus and axons that synapse on neurons in the somatosensory cortex. After cortical lesions that damage mature thalamocortical fibers in the somatosensory cortex, we have attempted to reestablish somatosensory cortical function by grafting embryonic neocortical cells into the lesioned area. Such grafts survive in adult host animals but are not innervated by thalamic neurons, and consequently the grafted neurons show little if any spontaneous activity and no responses to cutaneous stimuli. We have reported that transection of peripheral sensory nerves prior to grafting ``conditions'' or ``primes'' the thalamic neurons in the ventrobasal complex so that they extend axons into grafts subsequently placed in the cortical domain of the cut nerve. In this report we present evidence that the ingrowth of ventrobasal fibers leads to graft neurons that become functionally integrated into the sensory circuitry of the host brain. Specifically, the conditioning lesions made prior to grafting produce graft neurons that are spontaneously active and can be driven by natural activation of cutaneous receptors or electrical stimulation of the transected nerve after it regenerates. Furthermore, oxidative metabolism in these grafts reaches levels that are comparable to normal cortex, whereas without prior nerve cut, oxidative metabolism is abnormally low in neocortical grafts. We conclude that damage to the sensory periphery transsynaptically stimulates reorganization of sensory pathways through mechanisms that include axonal elongation and functional synaptogenesis.

Ebner, Ford F.; Erzurumlu, Reha S.; Lee, Stefan M.



Anatomical coupling of sensory and motor nerve trajectory via axon tracking.  


It is a long-standing question how developing motor and sensory neuron projections cooperatively form a common principal grid of peripheral nerve pathways relaying behavioral outputs and somatosensory inputs. Here, we explored this issue through targeted cell lineage and gene manipulation in mouse, combined with in vitro live axon imaging. In the absence of motor projections, dorsal (epaxial) and ventral (hypaxial) sensory projections form in a randomized manner, while removal of EphA3/4 receptor tyrosine kinases expressed by epaxial motor axons triggers selective failure to form epaxial sensory projections. EphA3/4 act non-cell-autonomously by inducing sensory axons to track along preformed epaxial motor projections. This involves cognate ephrin-A proteins on sensory axons but is independent from EphA3/4 signaling in motor axons proper. Assembly of peripheral nerve pathways thus involves motor axon subtype-specific signals that couple sensory projections to discrete motor pathways. PMID:21791286

Wang, Liang; Klein, Rüdiger; Zheng, Binhai; Marquardt, Till



Altered temperature and taste responses from cross-regenerated sensory nerves in the rat's tongue  

PubMed Central

1. The chorda tympani nerve, which innervates the front of the rat tongue, was found to be much less responsive to tongue cooling than the IXth nerve, which innervates the back of the tongue. The two nerves also differed in their relative responsiveness to various taste chemicals. 2. Through cross-union the IXth nerve was made to innervate the front of the tongue, and in other rats the chorda tympani nerve the back of the tongue. 3. After an average of 15 post-operative weeks, electrophysiological recordings of whole nerve action potential discharges were made from normal, control regenerated, and cross-regenerated nerves. Cooling, and chemical and mechanical stimulation of the tongue demonstrated that the control regenerated and cross-regenerated nerves had established functional connexions. 4. Neither the response to cooling nor the relative taste responses were altered by either of two types of control chorda tympani nerve regeneration. 5. In contrast, the cross-regenerated chorda increased its responsiveness to tongue cooling and the cross-regenerated IXthe nerve lost much of its responsiveness to cooling. 6. Cross-regeneration also caused the relative taste responses to change and appear quite similar to the responses obtained from the nerve which normally innervated that tongue region (e.g. the cross-regenerated IXth nerve responded like a chorda tympani nerve). 7. It is suggested that the sensory response evoked in the chorda tympani and IXth nerves by tongue cooling or taste stimulation is at least partially dependent upon the character of the tongue tissue in which the nerve terminates—the epithelium at the front differs from that at the back of the rat tongue. 8. These results rule out the following two hypotheses: (a) that the nerve ending itself functions as a taste receptor in direct contact with applied chemicals and yet is uninfluenced by the character of the tissue in which it terminates, (b) that assuming the taste bud cells are an integral part of the receptive process, the taste nerve ending determines the chemical specificity of the taste cell which it induces, without any previous modification of the nerve by the tissue in which it terminates.

Oakley, B.



An artificial arm/hand system with a haptic sensory function using electric stimulation of peripheral sensory nerve fibers.  


We are currently developing an artificial arm/hand system which is capable of sensing stimuli and then transferring these stimuli to users as somatic sensations. Presently, we are evoking the virtual somatic sensations by electrically stimulating a sensory nerve fiber which innervates a single mechanoreceptor unit at the target area; this is done using a tungsten microelectrode that was percutaneously inserted into the use's peripheral nerve (a microstimulation method). The artificial arm/hand system is composed of a robot hand equipped with a pressure sensor system on its fingers. The sensor system detects mechanical stimuli, which are transferred to the user by means of the microstimulation method so that the user experiences the stimuli as the corresponding somatic sensations. In trials, the system worked satisfactorily and there was a good correlation between the pressure applied to the pressure sensors on the robot fingers and the subjective intensities of the evoked pressure sensations. PMID:24110391

Mabuchi, Kunihiko



Manually-stimulated recovery of motor function after facial nerve injury requires intact sensory input.  


We have recently shown in rat that daily manual stimulation (MS) of vibrissal muscles promotes recovery of whisking and reduces polyinnervation of muscle fibers following repair of the facial nerve (facial-facial anastomosis, FFA). Here, we examined whether these positive effects were: (1) correlated with alterations of the afferent connections of regenerated facial motoneurons, and (2) whether they were achieved by enhanced sensory input through the intact trigeminal nerve. First, we quantified the extent of total synaptic input to motoneurons in the facial nucleus using synaptophysin immunocytochemistry following FFA with and without subsequent MS. We found that, without MS, this input was reduced compared to intact animals. The number of synaptophysin-positive terminals returned to normal values following MS. Thus, MS appears to counteract the deafferentation of regenerated facial motoneurons. Second, we performed FFA and, in addition, eliminated the trigeminal sensory input to facial motoneurons by extirpation of the ipsilateral infraorbital nerve (IONex). In this paradigm, without MS, vibrissal motor performance and pattern of end-plate reinnervation were as aberrant as after FFA without MS. MS did not influence the reinnervation pattern after IONex and functional recovery was even worse than after IONex without MS. Thus, when the sensory system is intact, MS restores normal vibrissal function and reduces the degree of polyinnervation. When afferent inputs are abolished, these effects are eliminated or even reversed. We conclude that rehabilitation strategies must be carefully designed to take into account the extent of motor and/or sensory damage. PMID:18381213

Pavlov, Stoyan P; Grosheva, Maria; Streppel, Michael; Guntinas-Lichius, Orlando; Irintchev, Andrey; Skouras, Emmanouil; Angelova, Srebrina K; Kuerten, Stefanie; Sinis, Nektarios; Dunlop, Sarah A; Angelov, Doychin N



Local substitution of GDF-15 improves axonal and sensory recovery after peripheral nerve injury.  


The growth/differentiation factor-15, GDF-15, has been found to be secreted by Schwann cells in the lesioned peripheral nervous system. To investigate whether GDF-15 plays a role in peripheral nerve regeneration, we substituted exogenous GDF-15 into 10-mm sciatic nerve gaps in adult rats and compared functional and morphological regeneration to a vehicle control group. Over a period of 11 weeks, multiple functional assessments, including evaluation of pinch reflexes, the Static Sciatic Index and of electrophysiological parameters, were performed. Regenerated nerves were then morphometrically analyzed for the number and quality of regenerated myelinated axons. Substitution of GDF-15 significantly accelerated sensory recovery while the effects on motor recovery were less strong. Although the number of regenerated myelinated axons was significantly reduced after GDF-15 treatment, the regenerated axons displayed advanced maturation corroborating the results of the functional assessments. Our results suggest that GDF-15 is involved in the complex orchestration of peripheral nerve regeneration after lesion. PMID:22955564

Mensching, Leonore; Börger, Ann-Kathrin; Wang, Xialong; Charalambous, Petar; Unsicker, Klaus; Haastert-Talini, Kirsten



Segregation of NGF receptor in sensory receptors, nerves and local cells of teeth and periodontium demonstrated by EM immunocytochemistry  

Microsoft Academic Search

Summary Nerve growth factor receptor immunoreactivity (NGFR-IR) in sensory nerves and somatosensory receptors of adult rat dental and periodontal tissue was analysed using a monoclonal antibody (192-IgG) and electron microscopy. In dental and periodontal nerves, the unmyelinated axons and their Schwann cells had occasional labelling of their cell membranes, and myelinated axons had none. Dental free nerve endings in predentin

M. R. Byers



Nerve growth factor protects adult sensory neurons from cell death and atrophy caused by nerve injury  

Microsoft Academic Search

Summary The reaction of dorsal root ganglia (DRG) neurons to axotomy and its alteration by locally supplied nerve growth factor (NGF) were examined in adult rats. Surgically implanted silicone chambers attached to the severed tip of the sciatic nerve acted as reservoirs capable of providing prolonged access of NGF to the site of injury. The time course of NGF activity

Keith M. Rich; Jack R. Luszczynski; Patricia A. Osborne; Eugene M. Johnson



Cough Sensors. III. Opioid and Cannabinoid Receptors on Vagal Sensory Nerves  

Microsoft Academic Search

Cough is a persistent symptom of many inflammatory airways' diseases. Cough is mediated by receptors sited on sensory nerves\\u000a and then through vagal afferent pathways, which terminate in the brainstem respiratory centre. Cough is often described as\\u000a an unmet clinical need. Opioids are the only prescription-based anti-tussives currently available in the UK. They possess\\u000a limited efficacy and exhibit serious unwanted

M. G. Belvisi; D. J. Hele


?? T cells infiltrating sensory nerve biopsies from patients with inflammatory neuropathy  

Microsoft Academic Search

Sensory nerve biopsy specimens from patients with Guillain Barré syndrome (GBS), chronic inflammatory demyelinating polyneuropathy\\u000a (CIDP), and controls consisting of other neuropathies, were examined in order to characterise the nature and intensity of\\u000a any inflammatory infiltrate. In order to establish whether ?? T cells were present in these infiltrates we examined the expression\\u000a of ?? and ?? T cell receptors

John Winer; Sharon Hughes; Joanne Cooper; Anne Ben-Smith; Caroline Savage



Modelled temperature-dependent excitability behaviour of a generalised human peripheral sensory nerve fibre  

Microsoft Academic Search

The objective of this study was to determine if a recently developed human Ranvier node model, which is based on a modified\\u000a version of the Hodgkin–Huxley model, could predict the excitability behaviour in human peripheral sensory nerve fibres with\\u000a diameters ranging from 5.0 to 15.0 ?m. The Ranvier node model was extended to include a persistent sodium current and was

Jacoba E. Smit; Tania Hanekom; Johan J. Hanekom



Sensory nerves and nitric oxide contribute to reflex cutaneous vasodilation in humans.  


We tested the hypothesis that inhibition of cutaneous sensory nerves would attenuate reflex cutaneous vasodilation in response to an increase in core temperature. Nine subjects were equipped with four microdialysis fibers on the forearm. Two sites were treated with topical anesthetic EMLA cream for 120 min. Sensory nerve inhibition was verified by lack of sensation to a pinprick. Microdialysis fibers were randomly assigned as 1) lactated Ringer (control); 2) 10 mM nitro-L-arginine methyl ester (L-NAME) to inhibit nitric oxide synthase; 3) EMLA + lactated Ringer; and 4) EMLA + L-NAME. Laser-Doppler flowmetry was used as an index of skin blood flow, and blood pressure was measured via brachial auscultation. Subjects wore a water-perfused suit, and oral temperature was monitored as an index of core temperature. The suit was perfused with 50°C water to initiate whole body heat stress to raise oral temperature 0.8°C above baseline. Cutaneous vascular conductance (CVC) was calculated and normalized to maximal vasodilation (%CVC(max)). There was no difference in CVC between control and EMLA sites (67 ± 5 vs. 69 ± 6% CVC(max)), but the onset of vasodilation was delayed at EMLA compared with control sites. The L-NAME site was significantly attenuated compared with control and EMLA sites (45 ± 5% CVC(max); P < 0.01). Combined EMLA + L-NAME site (25 ± 6% CVC(max)) was attenuated compared with control and EMLA (P < 0.001) and L-NAME only (P < 0.01). These data suggest cutaneous sensory nerves contribute to reflex cutaneous vasodilation during the early, but not latter, stages of heat stress, and full expression of reflex cutaneous vasodilation requires functional sensory nerves and NOS. PMID:23408029

Wong, Brett J



Sensory and sympathetic nerve contributions to the cutaneous vasodilator response from a noxious heat stimulus.  


We investigated the roles of sensory and noradrenergic sympathetic nerves on the cutaneous vasodilator response to a localized noxious heating stimulus. In two separate studies, four forearm skin sites were instrumented with microdialysis fibres, local heaters and laser-Doppler probes. Skin sites were locally heated from 33 to 42 °C or rapidly to 44 °C (noxious). In the first study, we tested sensory nerve involvement using EMLA cream. Treatments were as follows: (1) control 42 °C; (2) EMLA 42 °C; (3) control 44°C; and (4) EMLA 44 °C. At the EMLA-treated sites, the axon reflex was reduced compared with the control sites during heating to 42 °C (P < 0.05). There were no differences during the plateau phase (P > 0.05). At both the sites heated to 44 °C, the initial peak and nadir became indistinguishable, and the EMLA-treated sites were lower compared with the control sites during the plateau phase (P < 0.05). In the second study, we tested the involvement of noradrenergic sympathetic nerves in response to the noxious heating using bretylium tosylate (BT). Treatments were as follows: (1) control 42 °C; (2) BT 42 °C; (3) control 44 °C; and (4) BT 44 °C. Treatment with BT at the 42 °C sites resulted in a marked reduction in both the axon reflex and the secondary plateau (P < 0.05). At the 44 °C sites, there was no apparent initial peak or nadir, but the plateau phase was reduced at the BT-treated sites (P < 0.05). These data suggest that both sympathetic nerves and sensory nerves are involved during the vasodilator response to a noxious heat stimulus. PMID:21890519

Carter, Stephen J; Hodges, Gary J



Localization of NADPH Oxidase in Sympathetic and Sensory Ganglion Neurons and Perivascular Nerve Fibers  

PubMed Central

Superoxide anion (O2?•) production was previously reported to be increased in celiac ganglia (CG) during DOCA-salt hypertension, possibly via activation of the reduced nicotinamide-adenine dinucleotide phosphate (NADPH) oxidase. This suggested a role for neuronal NADPH oxidase in autonomic neurovascular control. However, the expression and localization of NADPH oxidase in the peripheral neurons is not fully known. The purpose of this study was to examine the subcellular localization of NADPH oxidase in sympathetic and sensory ganglion neurons and perivascular nerve fibers. In rat CG, p22phox and neuropeptide Y (NPY) were colocalized in all neurons. P22phox was also localized to dorsal root ganglia (DRG) neurons that contain calcitonin gene related peptide (CGRP). In mesenteric arteries, p22phox and p47phox were colocalized with NPY or CGRP in perivascular nerve terminals. A similar pattern of nerve terminal staining of p22phox and p47phox was also found in cultured CG neurons and nerve growth factor (NGF)-differentiated PC12 cells. These data demonstrate a previously uncharacterized localization of NADPH oxidase in perivascular nerve fibers. The presence of a O2?• – generating enzyme in close vicinity to the sites of neurotransmitter handling in the nerve fibers suggests the possibility of novel redox-mediated mechanisms in peripheral neurovascular control.

Cao, Xian; Demel, Stacie L.; Quinn, Mark T.; Galligan, James J.; Kreulen, David L.



Contribution of collateral sprouting to the sensory and sudomotor recovery in the human palm after peripheral nerve injury.  


The contribution of collateral sprouting to the sensory and sudomotor recovery was studied in 52 patients aged 3-66 years (mean 35.5 years) from 2 to 9 years following nerve injury and repair. The study included three groups of patients: (1) patients with complete division of median and ulnar nerves (skin reinnervation exclusively due to axon regeneration), (2) patients with isolated division of ulnar or median nerve (skin reinnervation due to axon regeneration and possible collateral sprouting), and (3) patients in whom injured axons failed to regenerate (skin reinnervation exclusively due to collateral sprouting). The end stage of sensory and sudomotor recovery was studied by: clinical methods, sensory nerve action potential (SNAP) measurements, sympathetic skin response (SSR) and the ninhydrin test. We found that recovery of sensory and sudomotor function in groups 1 and 2 was similar. End-stage sudomotor and sensory recovery within the autonomous area of the nerve did not depend on possible collateral reinnervation. Collateral reinnervation from the uninjured nerve was limited to the border innervation area of the palm and ring finger. Adjacent uninjured nerve may contribute to sprouting of nociceptive axons providing a protective function. PMID:9849363

Ahcan, U; Arn?z, Z M; Bajrovi?, F; Janko, M



Central nervous system and peripheral nerve growth factor provide trophic support critical to mature sensory neuronal survival  

Microsoft Academic Search

Primary sensory neurones in cranial and dorsal root ganglia (DRG) of adult animals are generally thought to be maintained through connections with their peripheral (but not central) targets by trophic factor(s) other than nerve growth factor (NGF)1. Damage to the peripheral process of sensory neurones results in a dramatic response or even death of the neurones, whereas axotomy (cutting) of

Eugene M. Johnson; Henry K. Yip



Microscopic clusters of sensory neurons in c1 spinal nerve roots and in the c1 level of the spinal accessory nerve in adult humans.  


This study examined C1 spinal nerve roots and their anastomotic connections with the spinal accessory nerve for histological evidence of sensory neurons in adult humans. C1 spinal nerves and roots with the adjacent segments of the spinal accessory nerve and the spinal cord were dissected en bloc from cadaveric specimens, and prepared for histological study. Results show that in 39.3% of specimens studied, no sensory component to the C1 spinal nerve could be identified. The C1 dorsal root was present 35.7% of the time, and when present it always contained neuronal cell bodies. In the remaining specimens, the sensory contribution to the C1 spinal nerve came through an anastomotic connection with the spinal accessory nerve. The investigators were able to identify clusters of neuronal cell bodies along the spinal accessory nerve at the level of C1 in 100% of the specimens examined. Anat Rec, 296:1588-1593, 2013. © 2013 Wiley Periodicals, Inc. PMID:23929774

Hovorka, Michelle S; Uray, Nandor J



Store-operated calcium entry in vagal sensory nerves is independent of Orai channels.  


Vagal sensory nerves innervate the majority of visceral organs (e.g., heart, lungs, GI tract, etc) and their activation is critical for defensive and regulatory reflexes. Intracellular Ca(2+) is a key regulator of neuronal excitability and is largely controlled by the Ca(2+) stores of the endoplasmic reticulum. In other cell types store-operated channels (SOC) have been shown to contribute to the homeostatic control of intracellular Ca(2+). Here, using Ca(2+) imaging, we have shown that ER depletion in vagal sensory neurons (using thapsigargin or caffeine) in the absence of extracellular Ca(2+) evoked Ca(2+) influx upon re-introduction of Ca(2+) into the extracellular buffer. This store-operated Ca(2+) entry (SOCE) was observed in approximately 25-40% of vagal neurons, equally distributed among nociceptive and non-nociceptive sensory subtypes. SOCE was blocked by Gd(3+) but not by the Orai channel blocker SKF96365. We found Orai channel mRNA in extracts from whole vagal ganglia, but when using single cell RT-PCR analysis we found only 3 out of 34 neurons expressed Orai channel mRNA, indicating that Orai channel expression in the vagal ganglia was likely derived from non-neuronal cell types. Confocal microscopy of vagal neurons in 3 day cultures demonstrated rich ER tracker fluorescence throughout axonal and neurite structures and ER store depletion (thapsigargin) evoked Ca(2+) transients from these structures. However, no SOCE could be detected in the axonal/neurite structures of vagal neurons. We conclude that SOCE occurs in vagal sensory neuronal cell bodies through non-Orai mechanisms but is absent at nerve terminals. PMID:23399679

Hooper, Justin Shane; Hadley, Stephen H; Mathews, Adithya; Taylor-Clark, Thomas E



Localization of mu-opioid receptor 1A on sensory nerve fibers in human skin.  


Opioid peptides are endogenous neuromodulators that play a major role in the nociceptive pathway by interacting with opioid receptors. So far, four opioid receptors (micro-, delta-, kappa-, orphan-receptor) have been cloned with a wide distribution in the central and peripheral nervous system. In the present study, we give first evidence for the presence of the micro-opioid receptor (MOR) isoform 1A in nerve fibers of human skin. Immunohistochemical analysis revealed MOR immunoreactivity to be present in dermal and epidermal nerve fibers. Double-immunofluorescence staining revealed that MOR is present on calcitonin gene-related protein (CGRP)-positive sensory nerve fibers, while autonomic nerves of blood vessels, hair follicles, or skin glands were negative. In diseased skin such as psoriasis vulgaris, atopic dermatitis, and prurigo nodularis, distribution of MOR 1A immunoreactivity was similar to that of normal skin. These findings expand our knowledge about a direct regulatory role of cutaneous opioid receptors in the skin. Thus, peripheral cutaneous opioid receptors may be involved in the transmission of pain and pruritus, respectively. This is supported by previous observation that opioid receptor antagonists may significantly diminish experimentally evoked histamine-induced itch of the skin. Together, our findings contribute to the understanding of the high antipruritic potency of opioid receptor antagonists in various skin and systemic diseases. PMID:12468112

Ständer, Sonja; Gunzer, Matthias; Metze, Dieter; Luger, Thomas; Steinhoff, Martin



On the relationship between nociceptive evoked potentials and intraepidermal nerve fiber density in painful sensory polyneuropathies.  


This study analyzed the relationship between the density of intraepidermal nerve fibers (IENF) and the characteristics of either nociceptive laser-evoked potentials (LEPs) or contact heat-evoked potentials (CHEPs) in patients with painful sensory polyneuropathy with the aim to determine which parameters of LEPs and CHEPs more reliably reflect IENF loss. A total of 96 patients and 35 healthy volunteers took part in the study. Based on clinical examination, nerve conduction tests, and quantitative sensory testing, we identified 52 patients with small-fiber neuropathy (SFN), 40 with mixed (small-fiber and large-fiber) neuropathy (MFN), and 4 who were excluded from the analysis because of no evidence of involvement of small fibers. The latency of the N2 was delayed for both LEPs and CHEPs in patients with MFN and for CHEPs only in patients with SFN. The amplitude of the vertex N2/P2 potential was similarly reduced in both types of neuropathy, but LEPs were more frequently absent than CHEPs in MFN patients (68% vs 40%). In general, latency and amplitude of LEPs and CHEPs were well correlated with IENF density. SFN patients were characterized by abnormal EPs and slightly decreased but morphologically abnormal IENF. MFN patients were characterized by frequently absent LEPs and CHEPs and a rather severe IENF loss. The correlation between nociceptive evoked potentials (laser-evoked potentials and contact heat-evoked potentials) and skin biopsy aids in the diagnosis of painful neuropathies. PMID:21185650

Casanova-Molla, Jordi; Grau-Junyent, Josep Maria; Morales, Merche; Valls-Solé, Josep



Early use of artificial sensibility to improve sensory recovery after repair of the median and ulnar nerve.  


Artificial sensibility based on use of a "tactile glove" which substitutes for lack of sensory afferent inflow with acoustic feedback, was used early after repair of the median and ulnar nerves in a 21-year-old man. After six and 12 months the functional outcome exceeded what is expected in adults, and analysis with calculations for the minimal detectable change (MDC) in tactile gnosis showed a true change. This case highlights the timing of sensory re-education after nerve repair and also emphasises the importance of early restitution of afferent inflow from a denervated hand during rehabilitation. PMID:12625396

Rosén, Birgitta; Lundborg, Göran



Does low-intensity helium-neon laser irradiation alter sensory nerve active potentials or distal latencies  

SciTech Connect

The effect of 1 mW helium neon continuous-wave (0.633 microns) laser irradiation on superficial radical sensory and median sensory nerve function was examined in a double-blind, controlled study involving 40 volunteers. No differences in action potential amplitudes, distal latencies, or forearm skin temperatures were found between the treated and control groups either at the time of irradiation or at subsequent evaluations 15 and 30 minutes later. As a result, we are unable to confirm reports that low-energy lasers of this power and wavelength alter nerve function.

Basford, J.R.; Daube, J.R.; Hallman, H.O.; Millard, T.L.; Moyer, S.K. (Mayo Clinic and Foundation, Rochester, MN (USA))



Somatosensory evoked potentials following nerve and segmental stimulation do not confirm cervical radiculopathy with sensory deficit.  

PubMed Central

Twenty eight patients with unilateral cervical radiculopathy were studied by somatosensory evoked potentials (SEPs) from nerve stimulation at the wrist and from skin stimulation at the first, third or fifth finger depending on the root involved. In order to evaluate the reliability of various "radicular SEP patterns" as described in the literature, absolute latencies and side-to-side differences of the brachial plexus component from the supraclavicular fossa (N9), the medullary component (N13) from the cervical vertebra Cv7, and the primary cortical component (N20, P25) were assessed. Side-to-side differences of the amplitudes of N20/P25 and of the conduction times across the intervertebral fossa (interval N9-N13) were analysed. After nerve stimulation, 68% of the patients had false negative findings on the symptomatic, while 36% had positive findings on the asymptomatic side. After segmental stimulation, 72% of the patients had false negative findings on the symptomatic, while 22% had positive findings on the asymptomatic side. It is concluded that SEPs following nerve and segmental stimulation do not reliably confirm clear-cut already established diagnoses of unilateral radiculopathy with sensory and motor deficit. Therefore, they will not be helpful in the electrophysiological investigation of cervicobrachialgias of unknown origin.

Schmid, U D; Hess, C W; Ludin, H P



[Preliminary study on simulating sensory nerves of intestinal contents using ultrasound detecting system].  


Successful assessing intestinal lumen content with ultrasound signals might lay a strong basis for the development of the artificial anal sphincter. In the present study, we utilized a modified MLU02-212 ultrasonic gas bubble detector to test the distal part of proximal colon in each rabbit, for the group of twenty healthy New Zealand rabbits. Voltage signals of solid, liquid, gas and empty content of the lumen were collected and compared. The results indicated that there were significant differences among the voltage signals in the 4 conditions (P = 0.000), respectively. Multiple comparison showed significant differences existed in any pair of the four conditions (P = 0.000). Three signal non-overlapping regions existed in these 4 conditions. Thus it seemed that ultrasound could be utilized to distinguish various contents inside the intestinal lumen and could act as "artificial sensory nerve". PMID:22616169

Li, Jianguo; Huang, Zonghai; Shi, Fujun; Chen, Fei; Zhang, Quanan



The effect of aging on the density of the sensory nerve fiber innervation of bone and acute skeletal pain.  


As humans age there is a decline in most sensory systems including vision, hearing, taste, smell, and tactile acuity. In contrast, the frequency and severity of musculoskeletal pain generally increases with age. To determine whether the density of sensory nerve fibers that transduce skeletal pain changes with age, calcitonin gene related peptide (CGRP) and neurofilament 200 kDa (NF200) sensory nerve fibers that innervate the femur were examined in the femurs of young (4-month-old), middle-aged (13-month-old) and old (36-month-old) male F344/BNF1 rats. Whereas the bone quality showed a significant age-related decline, the density of CGRP(+) and NF200(+) nerve fibers that innervate the bone remained remarkably unchanged as did the severity of acute skeletal fracture pain. Thus, while bone mass, quality, and strength undergo a significant decline with age, the density of sensory nerve fibers that transduce noxious stimuli remain largely intact. These data may in part explain why musculoskeletal pain increases with age. PMID:20947214

Jimenez-Andrade, Juan M; Mantyh, William G; Bloom, Aaron P; Freeman, Katie T; Ghilardi, Joseph R; Kuskowski, Michael A; Mantyh, Patrick W



Capsaicin Combined with Local Anesthetics Preferentially Prolongs Sensory/Nociceptive Block in Rat Sciatic Nerve  

PubMed Central

Background Transient receptor potential vanilloid 1 channels integrate nociceptive stimuli and are predominantly expressed by unmyelinated C-fiber nociceptors, but not low-threshold mechanoreceptive sensory or motor fibers. A recent report showed that the transient receptor potential vanilloid 1 channel agonist capsaicin allows a hydrophilic quaternary ammonium derivative of lidocaine, QX-314, to selectively block C fibers without motor block. The authors tested whether a similar differential block would be produced using amphipathicN-methyl amitriptyline, amitriptyline, bupivacaine, or lidocaine, either alone or together with 0.05% capsaicin, in a rat sciatic nerve block model. Methods Rats (n = 8/group) were anesthetized with sevoflurane, and 0.2 ml of drug was injected either alone or with capsaicin (simultaneously or 10 min later) next to the sciatic nerve in the sciatic notch. Motor function was assessed by the extensor postural thrust. Nociception was evaluated by the nocifensive withdrawal reflex and vocalization evoked by pinch of a skin fold over the lateral metatarsus (cutaneous pain) with a serrated forceps. Results N-Methyl amitriptyline, amitriptyline, bupivacaine, or lidocaine, followed by injection of capsaicin 10 min later, each elicited a predominantly nociceptive-specific blockade. In comparison, simultaneous application of each local anesthetic with capsaicin did not elicit a clinically significant differential block, with the exception of N-methyl amitriptyline. Conclusions Both tertiary amine local anesthetics and their quaternary ammonium derivatives can elicit a predominantly sensory/nociceptor selective block when followed by injection of capsaicin. The combined application of transient receptor potential vanilloid 1 channel agonists and various local anesthetics or their quaternary ammonium derivatives is an appealing strategy to achieve a long-lasting differential block in regional analgesia.

Binshtok, Alexander M.; Wang, Chi-Fei; Hevelone, Nathanael D.; Bean, Bruce P.; Woolf, Clifford J.; Wang, Ging Kuo



TRESK channel contribution to nociceptive sensory neurons excitability: modulation by nerve injury  

PubMed Central

Background Neuronal hyperexcitability is a crucial phenomenon underlying spontaneous and evoked pain. In invertebrate nociceptors, the S-type leak K+ channel (analogous to TREK-1 in mammals) plays a critical role of in determining neuronal excitability following nerve injury. Few data are available on the role of leak K2P channels after peripheral axotomy in mammals. Results Here we describe that rat sciatic nerve axotomy induces hyperexcitability of L4-L5 DRG sensory neurons and decreases TRESK (K2P18.1) expression, a channel with a major contribution to total leak current in DRGs. While the expression of other channels from the same family did not significantly change, injury markers ATF3 and Cacna2d1 were highly upregulated. Similarly, acute sensory neuron dissociation (in vitro axotomy) produced marked hyperexcitability and similar total background currents compared with neurons injured in vivo. In addition, the sanshool derivative IBA, which blocked TRESK currents in transfected HEK293 cells and DRGs, increased intracellular calcium in 49% of DRG neurons in culture. Most IBA-responding neurons (71%) also responded to the TRPV1 agonist capsaicin, indicating that they were nociceptors. Additional evidence of a biological role of TRESK channels was provided by behavioral evidence of pain (flinching and licking), in vivo electrophysiological evidence of C-nociceptor activation following IBA injection in the rat hindpaw, and increased sensitivity to painful pressure after TRESK knockdown in vivo. Conclusions In summary, our results clearly support an important role of TRESK channels in determining neuronal excitability in specific DRG neurons subpopulations, and show that axonal injury down-regulates TRESK channels, therefore contributing to neuronal hyperexcitability.



Behavioural and histological observations of sensory impairment caused by tight ligation of the trigeminal nerve in mice.  


Dental treatments sometimes cause sensory impairment, especially in the region innervated by the third division of the trigeminal nerve. The most frequent symptoms are loss of sensation and abnormal sensation. Although most studies have addressed the neuropathic symptom "allodynia" using experimental animal models of the infraorbital nerve, there is little information regarding the sensory impairment that frequently occurs clinically. Therefore, different experimental models are required to clarify the mechanisms of the clinical effects, and previous experimental models have been limited to rats. Here, we report a sensory impairment model in mice whose mechanical touch threshold increased after tight ligation of the mental nerve. Habituation before surgery by mechanical touching of the face enabled us to observe the long-term chronological changes in sensation. The mechanical touch thresholds within the mental nerve region were measured for 70 postoperative (PO) days. Changes in the distribution of substance P (SP) were evaluated by immunohistochemistry to clarify the involvement of axonal flow in the sensory impairment and its recovery. The mechanical touch thresholds transiently increased by PO days 2-3, but decreased to the preoperative levels at around PO day 14. Apparent SP immunoreactivity was recognizable on the medial side to the ligation at PO days 2-3 and disappeared at PO day 7. These behavioural and immunohistochemical changes appeared to exhibit similar time courses, suggesting a possible relationship between them. Therefore, we suggest that our experimental mouse model could represent a new model for clarifying the mechanism of the sensory impairment caused by peripheral nerve injury. PMID:19409417

Seino, Hiroyuki; Seo, Kenji; Maeda, Takeyasu; Someya, Genji




PubMed Central

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.

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



Age-related changes in sensory and secretomotor nerve endings in the larynx of F344/N rat.  


The aim of the present study was to define the age-related changes in sensory and secretomotor nerve endings in the larynx of F344/N rats. For this purpose, laryngeal tissue sections obtained from 12-, 24- and 35-month-old F344/N rats were compared with respect to the density, distribution and morphology of various types of sensory and secretomotor nerve endings immunoreactive for protein gene product 9.5 (PGP 9.5), calcitonin gene-related peptide (CGRP) and substance P (SP). Two distinct forms of PGP 9.5-immunoreactive motor end-plates were noted; the large sized motor end-plates localized in thyroarytenoid and cricoarytenoid muscles were degenerated in aged rats, while the small sized motor end-plates, localized predominantly in vocal muscles, did not show any age-related changes. CGRP- and SP-immunoreactive nerve fibres of the laryngeal glands did not show any age-related changes. Subepithelial laminar nerve endings immunoreactive to PGP 9.5 showed degeneration with ageing. Aggregates of terminal arborisations in the subepithelial region were smaller in aged animals. PGP 9.5-immunostained taste cells and well-developed subgemmal network were abundant in 12- and 24-month-old rats, but only a few were noted in aged rats. The total number of taste buds decreased significantly with ageing. CGRP- and SP-immunostained taste bud-nerve endings were noted in 12- and 24-month-old rats, but only rarely in 35-month-old rats. The laryngeal epithelium contained PGP 9.5-, CGRP- and SP-immunoreactive thin free nerve endings with many varicosities; their number and distribution were similar between 12- and 24-month-old rats, while only a few endings were observed in 35-month-old rats. Our results indicated that ageing is associated with the reduction of laryngeal sensory and secretomotor nerve endings. PMID:12849090

Yamamoto, Yoshio; Tanaka, Shin; Tsubone, Hirokazu; Atoji, Yasuro; Suzuki, Yoshitaka


A pilot study of sensory feedback by transcutaneous electrical nerve stimulation to improve manipulation deficit caused by severe sensory loss after stroke.  


BACKGROUND: Sensory disturbance is common following stroke and can exacerbate functional deficits, even in patients with relatively good motor function. In particular, loss of appropriate sensory feedback in severe sensory loss impairs manipulation capability. We hypothesized that task-oriented training with sensory feedback assistance would improve manipulation capability even without sensory pathway recovery. METHODS: We developed a system that provides sensory feedback by transcutaneous electrical nerve stimulation (SENS) for patients with sensory loss, and investigated the feasibility of the system in a stroke patient with severe sensory impairment and mild motor deficit. The electrical current was modulated by the force exerted by the fingertips so as to allow the patient to identify the intensity. The patient had severe sensory loss due to a right thalamic hemorrhage suffered 27 months prior to participation in the study. The patient first practiced a cylindrical grasp task with SENS for 1 hour daily over 29 days. Pressure information from the affected thumb was fed back to the unaffected shoulder. The same patient practiced a tip pinch task with SENS for 1 hour daily over 4 days. Pressure information from the affected thumb and index finger was fed back to the unaffected and affected shoulders, respectively. We assessed the feasibility of SENS and examined the improvement of manipulation capability after training with SENS. RESULTS: The fluctuation in fingertip force during the cylindrical grasp task gradually decreased as the training progressed. The patient was able to maintain a stable grip force after training, even without SENS. Pressure exerted by the tip pinch of the affected hand was unstable before intervention with SENS compared with that of the unaffected hand. However, they were similar to each other immediately after SENS was initiated, suggesting that the somatosensory information improved tip pinch performance. The patient's manipulation capability assessed by the Box and Block Test score improved through SENS intervention and was partly maintained after SENS was removed, until at least 7 months after the intervention. The sensory test score, however, showed no recovery after intervention. CONCLUSIONS: We conclude that the proposed system would be useful in the rehabilitation of patients with sensory loss. PMID:23764012

Kita, Kahori; Otaka, Yohei; Takeda, Kotaro; Sakata, Sachiko; Ushiba, Junichi; Kondo, Kunitsugu; Liu, Meigen; Osu, Rieko



Selective regulation of nerve growth factor expression in developing cutaneous tissue by early sensory innervation  

PubMed Central

Background In the developing vertebrate peripheral nervous system, the survival of sympathetic neurons and the majority of sensory neurons depends on a supply of nerve growth factor (NGF) from tissues they innervate. Although neurotrophic theory presupposes, and the available evidence suggests, that the level of NGF expression is completely independent of innervation, the possibility that innervation may regulate the timing or level of NGF expression has not been rigorously investigated in a sufficiently well-characterized developing system. Results To address this important question, we studied the influence of innervation on the regulation of NGF mRNA expression in the embryonic mouse maxillary process in vitro and in vivo. The maxillary process receives its innervation from predominantly NGF-dependent sensory neurons of the trigeminal ganglion and is the most densely innervated cutaneous territory with the highest levels of NGF in the embryo. When early, uninnervated maxillary processes were cultured alone, the level of NGF mRNA rose more slowly than in maxillary processes cultured with attached trigeminal ganglia. In contrast to the positive influence of early innervation on NGF mRNA expression, the levels of brain-derived neurotrophic factor (BDNF) mRNA and neurotrophin-3 (NT3) mRNA rose to the same extent in early maxillary processes grown with and without trigeminal ganglia. The level of NGF mRNA, but not BDNF mRNA or NT3 mRNA, was also significantly lower in the maxillary processes of erbB3-/- mice, which have substantially fewer trigeminal neurons than wild-type mice. Conclusions This selective effect of initial innervation on target field NGF mRNA expression provokes a re-evaluation of a key assertion of neurotrophic theory that the level of NGF expression is independent of innervation.



Desensitization of bladder sensory fibers by intravesical capsaicin or capsaicin analogs. A new strategy for treatment of urge incontinence in patients with spinal detrusor hyperreflexia or bladder hypersensitivity disorders  

Microsoft Academic Search

Recent experimental studies have identified a category of unmyelinated type C bladder afferent fibers in the pelvic nerves which are extremely sensitive to capsaicin. Sensory input conveyed by these fibers triggers a spinal reflex which, in chronic spinalized animals, facilitates and controls micturition. In addition, bladder C fibers were also shown to have a role in bladder pain perception. In

F. Cruz



Cholecystokinin-8 enhances nerve growth factor synthesis and promotes recovery of capsaicin-induced sensory deficit  

PubMed Central

Alterations of nerve growth factor (NGF) expression have been demonstrated during peripheral nerve disease and the impaired expression or synthesis and transportation of NGF has been correlated with the pathogenesis of several peripheral neuropathies. Since exogenous NGF administration seems to cause undesired side-effects, therapeutical strategies based on the regulation of endogenous synthesis of NGF could prove useful in the clinical treatment of these disorders. The aim of the present study was to analyse the effects of exogenous peripheral administration of the neuropeptide cholecystokinin-8 (CCK-8) on endogenous NGF synthesis, NGF mRNA and distribution of peripheral neuropeptides which are known to be regulated by this neurotrophin. To address these questions we studied the effects of capsaicin (CAPS) before and after the administration of CCK-8 on NGF levels, NGF mRNA expression and localization, and the concentration of substance P (SP) and calcitonin gene-related peptide (CGRP) in peripheral tissue These studies demonstrate that administration of the CCK-8 induces an increase of NGF protein and mRNA in peripheral tissue. NGF level in paw skin of CAPS/CCK-8-treated mice is 3 fold higher than in controls (1241±110?pg?gr?1 of tissue wet weight versus 414±110?pg?gr?1 of controls) and nearly 6 fold higher than in CAPS-treated mice (1241±110?pg?gr?1 versus 248±27?pg?gr?1). The increase of NGF is correlated with the recovery of impaired nocifensive behaviour and with an overexpression of SP and CGRP. The evidence that CCK-8 promotes the recovery of sensory deficits suggests a potential clinical use for this neuropeptide in peripheral neuropathies.

Manni, Luigi; Lundeberg, Thomas; Tirassa, Paola; Aloe, Luigi



A semi-automated analysis method of small sensory nerve fibers in human skin-biopsies.  


Computerized detection method (CDM) software programs have been extensively developed in the field of astronomy to process and analyze images from nearby bright stars to tiny galaxies at the edge of the Universe. These object-recognition algorithms have potentially broader applications, including the detection and quantification of cutaneous small sensory nerve fibers (SSNFs) found in the dermal and epidermal layers, and in the intervening basement membrane of a skin punch biopsy. Here, we report the use of astronomical software adapted as a semi-automated method to perform density measurements of SSNFs in skin-biopsies imaged by Laser Scanning Confocal Microscopy (LSCM). In the first half of the paper, we present a detailed description of how the CDM is applied to analyze the images of skin punch biopsies. We compare the CDM results to the visual classification results in the second half of the paper. Abbreviations used in the paper, description of each astronomical tools, and their basic settings and how-tos are described in the appendices. Comparison between the normalized CDM and the visual classification results on identical images demonstrates that the two density measurements are comparable. The CDM therefore can be used - at a relatively low cost - as a quick (a few hours for entire processing of a single biopsy with 8-10 scans) and reliable (high-repeatability with minimum user-dependence) method to determine the densities of SSNFs. PMID:19852982

Tamura, Kazuyuki; Mager, Violet A; Burnett, Lindsey A; Olson, John H; Brower, Jeremy B; Casano, Ashley R; Baluch, Debra P; Targovnik, Jerome H; Windhorst, Rogier A; Herman, Richard M



The time-dependent difference of GAP-43 expression between sensory neurons and motoneurons after peripheral nerve transection.  


The L5 dorsal root ganglion (DRG) cells and L5 anterior horn (AH) cells of rats were studied and examined immunocytochemically after transection of the sciatic nerve to find out whether there would be time-dependent differences in the increase of growth-associated protein (GAP-43) expression between sensory neurons and motoneurons. On the seventh day after transection at mid-thigh level, the levels of GAP-43 in the DRG cells significantly increased, while those in the AH cells began to increase gradually from the 14th day onward. Transection at the piriform muscle level induced a significant increase in immunoreactivity of GAP-43 on the third day in the DRG cells, and on the seventh day in the AH cells. These results showed that sensory neurons expressed GAP-43 immunoreactivity earlier than motoneurons after peripheral nerve transection regardless of the site, suggesting that sensory neurons might start to produce cytoskeletons for axonal elongation earlier than motoneurons after nerve transection. PMID:10505438

Matsuura, Y; Ochi, M; Uchio, Y; Suzuki, G; Iwata, A



Median nerve sensory responses evoked by tactile stimulation of the finger proximal and distal phalanx in normal subjects.  


We compared the characteristics of near-nerve recorded sensory potentials elicited in response to electrical stimulation of digital nerves versus tactile stimulation of the digital skin in 17 healthy subjects with a mean age of 26 years. We also calculated the density of Meissner's corpuscles in the distal and proximal phalanx of digit III of 6 males who had suffered a violent death, but were free from diseases of the peripheral nerve system. Responses to tactile stimulation had a longer latency and lower amplitude than responses to electrical stimulation. Unlike electrically elicited responses, responses to tactile stimulation, which consisted of six or seven main spike components plus several minor components, were similar in recordings from the wrist and elbow. However, with proximal stimulation the electrically evoked responses were more compact and had a higher amplitude and area, whereas the tactile evoked potential became significantly reduced in maximum amplitude and cumulative area. The differences in sensory conduction between distal and proximal could reflect activation of a larger number of nerve fibers when electrical stimuli are used and a smaller amount of mechanoreceptors when tactile stimuli are used. PMID:8107703

Caruso, G; Nolano, M; Lullo, F; Crisci, C; Nilsson, J; Massini, R



Identification of sensory nerve cells in a peripheral organ (the intestine) of a mammal  

Microsoft Academic Search

It is commonly believed that the cell bodies of mammalian sensory neurons are contained within spinal and cranial sensory ganglia associated with the central nervous system or within the central nervous system itself. However, strong circumstantial evidence implies that some sensory neurons are contained entirely within the gastrointestinal tract.1,8,13 We have investigated this possibility by using intracellular methods to record

W. A. A. Kunze; J. C. Bornstein; J. B. Furness



Transcutaneous electrical nerve stimulation produces variable changes in somatosensory evoked potentials, sensory perception and pain threshold: clinical implications for pain relief.  

PubMed Central

Transcutaneous electrical nerve stimulation decreased early and late somatosensory evoked potential amplitudes and stimulus intensity ratings, and elevated sensory detection threshold, in normal subjects. Effects on pain threshold depended on pre-treatment threshold. These findings are relevant to treatment of clinical pain by transcutaneous electrical nerve stimulation.

Golding, J F; Ashton, H; Marsh, R; Thompson, J W



Mesenchymal stem cells in a polycaprolactone conduit promote sciatic nerve regeneration and sensory neuron survival after nerve injury.  


Despite the fact that the peripheral nervous system is able to regenerate after traumatic injury, the functional outcomes following damage are limited and poor. Bone marrow mesenchymal stem cells (MSCs) are multipotent cells that have been used in studies of peripheral nerve regeneration and have yielded promising results. The aim of this study was to evaluate sciatic nerve regeneration and neuronal survival in mice after nerve transection followed by MSC treatment into a polycaprolactone (PCL) nerve guide. The left sciatic nerve of C57BL/6 mice was transected and the nerve stumps were placed into a biodegradable PCL tube leaving a 3-mm gap between them; the tube was filled with MSCs obtained from GFP+ animals (MSC-treated group) or with a culture medium (Dulbecco's modified Eagle's medium group). Motor function was analyzed according to the sciatic functional index (SFI). After 6 weeks, animals were euthanized, and the regenerated sciatic nerve, the dorsal root ganglion (DRG), the spinal cord, and the gastrocnemius muscle were collected and processed for light and electron microscopy. A quantitative analysis of regenerated nerves showed a significant increase in the number of myelinated fibers in the group that received, within the nerve guide, stem cells. The number of neurons in the DRG was significantly higher in the MSC-treated group, while there was no difference in the number of motor neurons in the spinal cord. We also found higher values of trophic factors expression in MSC-treated groups, especially a nerve growth factor. The SFI revealed a significant improvement in the MSC-treated group. The gastrocnemius muscle showed an increase in weight and in the levels of creatine phosphokinase enzyme, suggesting an improvement of reinnervation and activity in animals that received MSCs. Immunohistochemistry documented that some GFP+ -transplanted cells assumed a Schwann-cell-like phenotype, as evidenced by their expression of the S-100 protein, a Schwann cell marker. Our findings suggest that using a PCL tube filled with MSCs is a good strategy to improve nerve regeneration after a nerve transection in mice. PMID:22646222

Frattini, Flávia; Lopes, Fatima Rosalina Pereira; Almeida, Fernanda Martins; Rodrigues, Rafaela Fintelman; Boldrini, Leonardo Cunha; Tomaz, Marcelo A; Baptista, Abrahăo Fontes; Melo, Paulo A; Martinez, Ana Maria Blanco



A comparison of nerve conduction velocities and current perception thresholds as correlates of clinical severity of diabetic sensory neuropathy.  

PubMed Central

Nerve conduction velocities (NCVs) are the standard measurements used to confirm the presence or absence of diabetic neuropathy. NCVs were contrasted with the newer technique of measurement of alternating current perception thresholds (CPTs) in assessing the quantitative level of correlation with severity of diabetic sensory neuropathy. A very detailed, scored neurological history (symptoms) and physical examination, emphasising sensory assessment, was conducted on 71 individuals with diabetic neuropathy of varying degrees of severity. Sensory and motor NCVs and CPTs at 5, 250, and 2000 Hz of the upper and lower extremities were determined for these individuals. In addition, vibration thresholds (VTs) were measured as a third modality. Twenty eight individuals underwent repeated evaluations at 2, 6, 10 and 12 months after the initial procedures. Using the results of 169 complete evaluations, correlations were determined between physical scores (PS) and symptoms scores (SS) and NCVs. NCV correlations with the SS were weaker than with the PS. The strongest of the correlations were found between the PS and motor NCVs of the median nerve (rho = 0.29) and the tibial nerve (rho = 0.38). Normal NCVs were present in the face of very significant historical and physical abnormality. Correlations of the SS and PS with both VTs and CPTs were higher than with the NCVs. CPTs proved the more effective as predictors of both symptomatic and physical impairment. NCVs appear to lack the resolving power necessary to evaluate subtle differences in clinical state of diabetic sensory neuropathy. The supplementary use of current perception testing may improve the quantitative assessment of this condition.

Rendell, M S; Katims, J J; Richter, R; Rowland, F



Low-level laser treatment improves longstanding sensory aberrations in the inferior alveolar nerve following surgical trauma  

NASA Astrophysics Data System (ADS)

The incidence of inferior alveolar nerve (IAN) damage following removal of 3rd molar teeth or saggital split osteotomy has been reported as high as up to 5.5% and 100% respectively. Sensory aberrations in the IAN persisting for longer than 6 months leave some degree of permanent defect. Low level laser treatment (LLL) has a reported beneficial effect on regeneration of traumatically injured nerves. The purpose of this double blind clinical trial was to examine the effects of LLL using a GaAlAs laser (820 nm, Ronvig, Denmark) on touch and temperature sensory perception following a longstanding post surgical IAN injury. Thirteen patients were divided into two groups, one of which received real LLL (4 by 6 J per treatment along the distribution of the IAN to a total of 20 treatments during a time period between 36 - 69 days) and the other equivalent placebo LLL. The degree of mechanoreceptor injury as assessed by Semmes Weinstein Monofilaments (North Coast Medical, USA) were comparable in the two groups prior to treatment (p equals 0.9). Subsequent to LLL the real laser treatment group showed a significant improvement in mechanoreceptor sensory testing (p equals 0.01) as manifested by a decrease in load threshold (g) necessary to elicit a response from the most damaged area. The placebo LLL group showed no significant improvement, In addition, the real LLL group reported a subjective improvement in sensory function too. The degree of thermal sensitivity disability as assessed using a thermotester (Philips, Sweden) was comparable between the two groups prior to LLL p equals 0.5). However, there was no significant improvement in thermal sensitivity post LLL for either the real or placebo laser treated groups. In conclusion, GaAlAs LLL can improve mechanoreceptor perception in longstanding sensory aberration in the IAN.

Khullar, Shelley M.; Brodin, P.; Barkvoll, P.; Haanoes, H. R.



Refining the Sensory and Motor Ratunculus of the Rat Upper Extremity Using fMRI and Direct Nerve Stimulation  

PubMed Central

It is well understood that the different regions of the body have cortical representations in proportion to the degree of innervation. Our current understanding of the rat upper extremity has been enhanced using functional MRI (fMRI), but these studies are often limited to the rat forepaw. The purpose of this study is to describe a new technique that allows us to refine the sensory and motor representations in the cerebral cortex by surgically implanting electrodes on the major nerves of the rat upper extremity and providing direct electrical nerve stimulation while acquiring fMRI images. This technique was used to stimulate the ulnar, median, radial, and musculocutaneous nerves in the rat upper extremity using four different stimulation sequences that varied in frequency (5 Hz vs. 10 Hz) and current (0.5 mA vs. 1.0 mA). A distinct pattern of cortical activation was found for each nerve. The higher stimulation current resulted in a dramatic increase in the level of cortical activation. The higher stimulation frequency resulted in both increases and attenuation of cortical activation in different regions of the brain, depending on which nerve was stimulated.

Cho, Younghoon R.; Pawela, Christopher P.; Li, Rupeng; Kao, Dennis; Schulte, Marie L.; Runquist, Matthew L.; Yan, Ji-Geng; Matloub, Hani S.; Jaradeh, Safwan S.; Hudetz, Anthony G.; Hyde, James S.



Inhibitory activity of the novel CB2 receptor agonist, GW833972A, on guinea-pig and human sensory nerve function in the airways  

PubMed Central

Background and purpose: Sensory nerves regulate central and local reflexes such as airway plasma protein leakage, bronchoconstriction and cough. Sensory nerve activity may be enhanced during inflammation such that these protective effects become exacerbated and deleterious. Cannabinoids are known to inhibit airway sensory nerve function. However, there is still controversy surrounding which receptor is involved in eliciting these effects. Experimental approach: We have adopted a pharmacological approach, including using a novel, more selective CB2 receptor agonist, GW 833972A (1000-fold selective CB2/CB1), and receptor selective antagonists to investigate the inhibitory activity of cannabinoids on sensory nerve activity in vitro and in vivo in guinea-pig models of cough and plasma extravasation. Key results: GW 833972A inhibited capsaicin-induced depolarization of the human and guinea-pig and prostaglandin E2 (PGE2) and hypertonic saline-induced depolarization of the guinea-pig isolated vagus nerve in vitro. GW 833972A also inhibited citric acid-induced cough but not plasma extravasation in the guinea-pig and this effect was blocked by a CB2 receptor antagonist. Conclusions and implications: This confirms and extends previous studies highlighting the role of CB2 receptors in the modulation of sensory nerve activity elicited both by the exogenous ligands capsaicin and hypertonic saline but also by endogenous modulators such as PGE2 and low pH stimuli. These data establish the CB2 receptor as an interesting target for the treatment of chronic cough.

Belvisi, M G; Patel, H J; Freund-Michel, V; Hele, D J; Crispino, N; Birrell, M A



Type-1 Angiotensin Receptors are Expressed and Transported in Motor and Sensory Axons of Rat Sciatic Nerves  

PubMed Central

Angiotensin II (Ang II) and its type-1 receptor (AT1) occur in neurons at multiple locations within the organism, but the basic biology of the receptor in the nervous system remains incompletely understood. We previously observed abundant AT1–like binding sites and intense expression of AT1 immunoreactivity in perikarya of the dorsal root ganglion and ventral horn of the rat spinal cord. We have now examined the receptor in rat sciatic nerve, including the dynamics of its axonal transport. Ligand-binding autoradiography of resting nerve showed “hot spots” of 125I-Ang II binding that could be specifically blocked by the AT1 antagonist, losartan. Immunohistochemistry with an AT1-antibody validated by Western blots also showed patches of AT1-reactivity in nerve. These patches were localized around large myelinated axons with faint immunoreactivity in their lumens. Sixteen hr after nerve ligation there was no change in the patches or hot spots, but luminal AT1-reactivity increased dramatically in a narrow zone immediately above the ligature. With double ligation there was a pronounced accumulation of AT1 immunoreactivity proximal to the upstream ligature and a very slight accumulation distal to the second ligature. This asymmetric pattern of accumulation, confirmed by quantitative receptor binding autoradiography, probably reflected axonal transport rather than local production of receptor. Retrograde tracing and stereological analysis to determine the source of transported AT1 indicated that many AT1-positive fibers arise in the ventral horn, and a larger number arise in dorsal root ganglia. A corresponding result was obtained with double-label immunohistochemistry of ligated nerve, which showed AT1 accumulations in both motor and sensory fibers. We conclude that somatic sensory and motor neurons of the rat export substantial quantities of AT1 into axons, which transport them to the periphery. The physiologic implications of this finding require further investigation.

Tang, Hui; Pavel, Jaroslav; Saavedra, Juan; Brimijoin, Stephen



[A case of acute autonomic, sensory and motor neuropathy with swelling and gadolinium enhancement of bilateral trigeminal nerve on MRI and dissociation between superficial and deep sensation disturbance].  


We report a case of a 46-year old man with acute autonomic, sensory and motor neuropathy (AASMN). He developed severe orthostatic hypotension, anuria,anhydrosis, tonic pupil with dysarthria, dysphagia, jaw claudication, and dysesthesia and sharp pain several days after symptom of upper respiratory infection. Neurological examination revealed severely decreased superficial sensation with normal deep sensation. Brain MRI findings showed bilateral trigeminal nerve swelling with gadolinium (Gd) enhancement. His motor and sensory symptoms and MRI abnormality were improved after the administration of intravenous immunoglobulin and intravenous methylprednisolone therapy; however his autonomic symptoms scarcely reacted to these immunotherapies. As long as we investigated in AASMN cases, bilateral trigeminal nerve swelling with Gd enhancement and dissociation between superficial and deep sensation disturbance have not reported, suggesting that the present case mainly disrupted C nerve fibers distributing postganglionic autonomic and temperature-pain sensory nerves. PMID:23470893

Naito, Hiroyuki; Doi, Hikaru; Inamizu, Saeko; Ito, Hijiri; Araki, Takehisa



Sensory Neuron Downregulation of the Kv9.1 Potassium Channel Subunit Mediates Neuropathic Pain following Nerve Injury  

PubMed Central

Chronic neuropathic pain affects millions of individuals worldwide, is typically long-lasting, and remains poorly treated with existing therapies. Neuropathic pain arising from peripheral nerve lesions is known to be dependent on the emergence of spontaneous and evoked hyperexcitability in damaged nerves. Here, we report that the potassium channel subunit Kv9.1 is expressed in myelinated sensory neurons, but is absent from small unmyelinated neurons. Kv9.1 expression was strongly and rapidly downregulated following axotomy, with a time course that matches the development of spontaneous activity and pain hypersensitivity in animal models. Interestingly, siRNA-mediated knock-down of Kv9.1 in naive rats led to neuropathic pain behaviors. Diminished Kv9.1 function also augmented myelinated sensory neuron excitability, manifested as spontaneous firing, hyper-responsiveness to stimulation, and persistent after-discharge. Intracellular recordings from ex vivo dorsal root ganglion preparations revealed that Kv9.1 knock-down was linked to lowered firing thresholds and increased firing rates under physiologically relevant conditions of extracellular potassium accumulation during prolonged activity. Similar neurophysiological changes were detected in animals subjected to traumatic nerve injury and provide an explanation for neuropathic pain symptoms, including poorly understood conditions such as hyperpathia and paresthesias. In summary, our results demonstrate that Kv9.1 dysfunction leads to spontaneous and evoked neuronal hyperexcitability in myelinated fibers, coupled with development of neuropathic pain behaviors.

Tsantoulas, Christoforos; Zhu, Lan; Shaifta, Yasin; Grist, John; Ward, Jeremy P. T.; Raouf, Ramin; Michael, Gregory J.; McMahon, Stephen B.



Vascularization of the dorsal root ganglia and peripheral nerve of the mouse: Implications for chemical-induced peripheral sensory neuropathies  

PubMed Central

Although a variety of industrial chemicals, as well as several chemotherapeutic agents used to treat cancer or HIV, preferentially induce a peripheral sensory neuropathy what remains unclear is why these agents induce a sensory vs. a motor or mixed neuropathy. Previous studies have shown that the endothelial cells that vascularize the dorsal root ganglion (DRG), which houses the primary afferent sensory neurons, are unique in that they have large fenestrations and are permeable to a variety of low and high molecular weight agents. In the present report we used whole-mount preparations, immunohistochemistry, and confocal laser scanning microscopy to show that the cell body-rich area of the L4 mouse DRG has a 7 fold higher density of CD31+ capillaries than cell fiber rich area of the DRG or the distal or proximal aspect of the sciatic nerve. This dense vascularization, coupled with the high permeability of these capillaries, may synergistically contribute, and in part explain, why many potentially neurotoxic agents preferentially accumulate and injure cells within the DRG. Currently, cancer survivors and HIV patients constitute the largest and most rapidly expanding groups that have chemically induced peripheral sensory neuropathy. Understanding the unique aspects of the vascularization of the DRG and closing the endothelial fenestrations of the rich vascular bed of capillaries that vascularize the DRG before intravenous administration of anti-neoplastic or anti-HIV therapies, may offer a mechanism based approach to attenuate these chemically induced peripheral neuropathies in these patients.

Jimenez-Andrade, Juan M; Herrera, Monica B; Ghilardi, Joseph R; Vardanyan, Marina; Melemedjian, Ohannes K; Mantyh, Patrick W



Continuous Femoral Nerve Blocks: The Impact of Catheter Tip Location Relative to the Femoral Nerve (Anterior Versus Posterior) on Quadriceps Weakness and Cutaneous Sensory Block  

PubMed Central

Background During a continuous femoral nerve block, the influence of catheter tip position relative to the femoral nerve on infusion characteristics remains unknown. Methods We inserted bilateral femoral perineural catheters in volunteers (ultrasound-guided, needle in-plane). Subjects’ dominant side was randomized to have the catheter tip placed either anterior or posterior to the femoral nerve. The contralateral limb received the alternative position. Ropivacaine 0.1% was administered through both catheters concurrently for 6 hours (4 mL/h). Outcome measures included the maximum voluntary isometric contraction (MVIC) of the quadriceps femoris muscle and tolerance to cutaneous electrical current over to the distal quadriceps tendon. Measurements were performed at Hour 0 (baseline), and on the hour until Hour 9, as well as Hour 22. The primary endpoint was the MVIC of the quadriceps at Hour 6. Results As a percentage of the baseline measurement, quadriceps MVIC for limbs with anterior (n=16) and posterior (n=16) catheter tip placement did not differ to a statistically significant degree at Hour 6 (mean [SD] 29% [26] vs. 30% [28], respectively; 95% CI: ?22% to 20%; p=0.931), or at any other time point. However, the maximum tolerance to cutaneous electrical current was higher in limbs with anterior compared to posterior catheter tip placement at Hour 6 (20 [23] vs. 6 [4] mA, respectively; 95% CI: 1 mA to 27 mA; p=0.035), as well as at Hours 1, 7, 8, and 9 (p<0.04). Conclusions This study documents the significant (70–80%) quadriceps femoris weakness induced by a continuous femoral nerve block infusion at a relatively low dose of ropivacaine (4 mg/h) delivered through a perineural catheter located both anterior and posterior to the femoral nerve. In contrast, an anterior placement increases cutaneous sensory block compared with a posterior insertion, without a concurrent relative increase in motor block.

Ilfeld, Brian M.; Loland, Vanessa J.; Sandhu, NavParkash S.; Suresh, Preetham J.; Bishop, Michael J.; Donohue, Michael C.; Ferguson, Eliza J.; Madison, Sarah J.



Selective decrease of small sensory neurons in lumbar dorsal root ganglia labeled with horseradish peroxidase after ND:YAG laser irradiation of the tibial nerve in the rat  

SciTech Connect

Recent electrophysiological evidence indicates that Q-switched Nd:YAG laser irradiation might have selective effects on neural impulse transmission in small slow conducting sensory nerve fibers as compared to large diameter afferents. In an attempt to clarify the ultimate fate of sensory neurons after laser application to their peripheral axons, we have used horseradish peroxidase (HRP) as a cell marker to retrogradely label sensory neurons innervating the distal hindlimb in the rat. Pulsed Nd:YAG laser light was applied to the tibial nerve at pulse energies of 70 or 80 mJ/pulse for 5 min in experimental rats. Seven days later HRP was applied to the left (laser-treated) and to the contralateral (untreated) tibial nerve proximal to the site of laser irradiation. In control animals the numbers of HRP-labeled dorsal root ganglion cells were not significantly different between the right and the left side. In contrast, after previous laser irradiation labeling was always less on the laser-treated side (2183 +/- 513 cells, mean +/- SEM) as compared to the untreated side (3937 +/- 225). Analysis of the dimensions of labeled cells suggested that the reduction of labeled cells on the laser-treated side was mainly due to a deficit in small sensory neurons. Since the conduction velocity of nerve fibers is related to the size of their somata, our histological data imply that laser light selectively affects retrograde transport mechanisms for HRP in slow conducting sensory nerve fibers.

Wesselmann, U.; Lin, S.F.; Rymer, W.Z. (Northwestern Univ. Medical School, Chicago, IL (USA))



Expression of vanilloid receptor subtype 1 in cutaneous sensory nerve fibers, mast cells, and epithelial cells of appendage structures.  


The vanilloid receptor subtype 1 (VR1)/(TRPV1), binding capsaicin, is a non-selective cation channel that recently has been shown in human keratinocytes in vitro and in vivo. However, a description of VR1 localization in other cutaneous compartments in particular cutaneous nerve fibers is still lacking. We therefore investigated VR1 immunoreactivity as well as mRNA and protein expression in a series (n = 26) of normal (n = 7), diseased (n = 13) [prurigo nodularis (PN) (n = 10), generalized pruritus (n = 1), and mastocytosis (n = 2)], and capsaicin-treated human skin (n = 6). VR1 immunoreactivity could be observed in cutaneous sensory nerve fibers, mast cells, epidermal keratinocytes, dermal blood vessels, the inner root sheet and the infundibulum of hair follicles, differentiated sebocytes, sweat gland ducts, and the secretory portion of eccrine sweat glands. Upon reverse transcriptase-polymerase chain reaction and Western blot analysis, VR1 was detected in mast cells and keratinocytes from human skin. In pruritic skin of PN, VR1 expression was highly increased in epidermal keratinocytes and nerve fibers, which was normalized after capsaicin application. During capsaicin therapy, a reduction of neuropeptides (substance P, calcitonin gene-related peptide) was observed. After cessation of capsaicin therapy, neuropeptides re-accumulated in skin nerves. In conclusion, VR1 is widely distributed in the skin, suggesting a major role for this receptor, e.g. in nociception and neurogenic inflammation. PMID:14987252

Ständer, Sonja; Moormann, Corinna; Schumacher, Mark; Buddenkotte, Jörg; Artuc, Metin; Shpacovitch, Victoria; Brzoska, Thomas; Lippert, Undine; Henz, Beate M; Luger, Thomas A; Metze, Dieter; Steinhoff, Martin



Differences between nerve terminal impulses of polymodal nociceptors and cold sensory receptors of the guinea-pig cornea.  


1. Extracellular recording techniques were used to study nerve terminal impulses (NTIs) recorded from single polymodal nociceptors and cold-sensitive receptors in guinea-pig cornea isolated in vitro. 2. The amplitude and time course of NTIs recorded from polymodal nociceptors was different from those of cold-sensitive receptors. 3. Bath application of tetrodotoxin (1 microM) changed the time course of spontaneous NTIs recorded from both polymodal and cold-sensitive receptors. 4. Bath application of lignocaine (lidocaine; 1-5 mM) abolished all electrical activity. 5. Local application of lignocaine (2.5 and 20 mM) through the recording electrode changed the time course of the NTIs recorded from polymodal nociceptors but not that of NTIs recorded from cold-sensitive nerve endings. 6. It is concluded that action potentials propagate actively in the sensory nerve endings of polymodal nociceptors. In contrast, cold-sensitive receptor nerve endings appear to be passively invaded from a point more proximal in the axon where the action potential can fail or be initiated. PMID:11389207

Brock, J A; Pianova, S; Belmonte, C




Microsoft Academic Search

Irvine, California 92664 The nervous systeni of polyclad flatworn-is is comprised of a number of nerve tracts which radiate outwards from at-i anterior ganglionic mass often called the brain. These nerve tracts branch and anastomose repeatedly to form a network of strands. Two such networks have beet-i recognized, ( 1) a ventral network of coarse nerves with a meshwork of



Plasticity in the expression of bradykinin binding sites in sensory neurons after mechanical nerve injury  

Microsoft Academic Search

The pro-inflammatory mediator bradykinin plays an important role in hyperalgesia during inflammatory conditions. Here, we used unilateral ligation of the sciatic nerve to investigate whether the expression of bradykinin binding sites in isolated rat dorsal root ganglion neurons is changed following nerve injury. Under control conditions, the percentage of neurons expressing bradykinin binding sites increased from 52% at day 0.8

M Petersen; A. S Eckert; G Segond von Banchet; B Heppelmann; A Klusch; K.-D Kniffki



Dietary sodium modulates the interaction between efferent and afferent renal nerve activity by altering activation of ?2-adrenoceptors on renal sensory nerves.  


Activation of efferent renal sympathetic nerve activity (ERSNA) increases afferent renal nerve activity (ARNA), which then reflexively decreases ERSNA via activation of the renorenal reflexes to maintain low ERSNA. The ERSNA-ARNA interaction is mediated by norepinephrine (NE) that increases and decreases ARNA by activation of renal ?(1)-and ?(2)-adrenoceptors (AR), respectively. The ERSNA-induced increases in ARNA are suppressed during a low-sodium (2,470 ± 770% s) and enhanced during a high-sodium diet (5,670 ± 1,260% s). We examined the role of ?(2)-AR in modulating the responsiveness of renal sensory nerves during low- and high-sodium diets. Immunohistochemical analysis suggested the presence of ?(2A)-AR and ?(2C)-AR subtypes on renal sensory nerves. During the low-sodium diet, renal pelvic administration of the ?(2)-AR antagonist rauwolscine or the AT1 receptor antagonist losartan alone failed to alter the ARNA responses to reflex increases in ERSNA. Likewise, renal pelvic release of substance P produced by 250 pM NE (from 8.0 ± 1.3 to 8.5 ± 1.6 pg/min) was not affected by rauwolscine or losartan alone. However, rauwolscine+losartan enhanced the ARNA responses to reflex increases in ERSNA (4,680 ± 1,240%·s), and renal pelvic release of substance P by 250 pM NE, from 8.3 ± 0.6 to 14.2 ± 0.8 pg/min. During a high-sodium diet, rauwolscine had no effect on the ARNA response to reflex increases in ERSNA or renal pelvic release of substance P produced by NE. Losartan was not examined because of low endogenous ANG II levels in renal pelvic tissue during a high-sodium diet. Increased activation of ?(2)-AR contributes to the reduced interaction between ERSNA and ARNA during low-sodium intake, whereas no/minimal activation of ?(2)-AR contributes to the enhanced ERSNA-ARNA interaction under conditions of high sodium intake. PMID:21106912

Kopp, Ulla C; Cicha, Michael Z; Smith, Lori A; Ruohonen, Saku; Scheinin, Mika; Fritz, Nicolas; Hökfelt, Tomas



Advanced Glycation End Products in Extracellular Matrix Proteins Contribute to the Failure of Sensory Nerve Regeneration in Diabetes  

PubMed Central

OBJECTIVE The goal of this study was to characterize glycation adducts formed in both in vivo extracellular matrix (ECM) proteins of endoneurium from streptozotocin (STZ)-induced diabetic rats and in vitro by glycation of laminin and fibronectin with methylglyoxal and glucose. We also investigated the impact of advanced glycation end product (AGE) residue content of ECM on neurite outgrowth from sensory neurons. RESEARCH DESIGN AND METHODS Glycation, oxidation, and nitration adducts of ECM proteins extracted from the endoneurium of control and STZ-induced diabetic rat sciatic nerve (3–24 weeks post-STZ) and of laminin and fibronectin that had been glycated using glucose or methylglyoxal were examined by liquid chromatography with tandem mass spectrometry. Methylglyoxal-glycated or unmodified ECM proteins were used as substrata for dissociated rat sensory neurons as in vitro models of regeneration. RESULTS STZ-induced diabetes produced a significant increase in early glycation N?-fructosyl-lysine and AGE residue contents of endoneurial ECM. Glycation of laminin and fibronectin by methylglyoxal and glucose increased glycation adduct residue contents with methylglyoxal-derived hydroimidazolone and N?-fructosyl-lysine, respectively, of greatest quantitative importance. Glycation of laminin caused a significant decrease in both neurotrophin-stimulated and preconditioned sensory neurite outgrowth. This decrease was prevented by aminoguanidine. Glycation of fibronectin also decreased preconditioned neurite outgrowth, which was prevented by aminoguanidine and nerve growth factor. CONCLUSIONS Early glycation and AGE residue content of endoneurial ECM proteins increase markedly in STZ-induced diabetes. Glycation of laminin and fibronectin causes a reduction in neurotrophin-stimulated neurite outgrowth and preconditioned neurite outgrowth. This may provide a mechanism for the failure of collateral sprouting and axonal regeneration in diabetic neuropathy.

Duran-Jimenez, Beatriz; Dobler, Darin; Moffatt, Sarah; Rabbani, Naila; Streuli, Charles H.; Thornalley, Paul J.; Tomlinson, David R.; Gardiner, Natalie J.



Systemic acetyl- l -carnitine eliminates sensory neuronal loss after peripheral axotomy: a new clinical approach in the management of peripheral nerve trauma  

Microsoft Academic Search

Several hundred thousand peripheral nerve injuries occur each year in Europe alone. Largely due to the death of around 40%\\u000a of primary sensory neurons, sensory outcome remains disappointingly poor despite considerable advances in surgical technique;\\u000a yet no clinical therapies currently exist to prevent this neuronal death. Acetyl-l-carnitine (ALCAR) is a physiological peptide with roles in mitochondrial bioenergetic function, which may

Andrew McKay Hart; Mikael Wiberg; Mike Youle; Giorgio Terenghi



Absence of large-diameter sensory fibres in a nerve to the cat humerus  

PubMed Central

A fine branch of the median nerve innervates the periosteum and medullary cavity of the cat humerus. After branching to innervate the periosteum on the medial surface of the humerus, the nerve enters and supplies the medullary cavity via a nutrient foramen, accompanied by a small artery and vein. The composition of the fibres in the nerve was examined using electron microscopy. Myelinated fibres with diameters of 0.8–6.6 µm and unmyelinated fibres with diameters of 0.1–1.4 µm were observed. These diameters indicate that afferent fibres of this nerve are confined within the Group III and IV categories, and may therefore be nociceptive or mechanoreceptive in function. In addition, autonomic efferent fibres may also be present in these fibre groups. As no fibre diameters greater than 7 µm were noted, it appears that Group I and II fibres are absent in this nerve. The fibre distribution suggests that the principal role of this nerve is to relay bone-related nociceptive or mechanoreceptive information to the central nervous system and to provide autonomic regulatory influences on the bone.

Ivanusic, Jason J; Mahns, David A; Sahai, Vineet; Rowe, Mark J



Topography and ultrastructure of sensory nerve endings in the joint capsules of the Kowari (Dasyuroides byrnei), an Australian marsupial.  


The present investigation in concerned with the topography and ultrastructure of sensory nerve endings in the joint capsules of the Kowari (Dasyuroides byrnei), an Australian marsupial. Material for light and electron microscopy was obtained from shoulder, elbow and knee joint capsules. On the basis of differences in the organization of the connective tissue belonging to the fibrous layer, 3 variants of capsule structure have been distinguished: a rigid, a flaccid and an intermediate type. Whilst the rigid type is characterized by dense connective tissue in the clearly demarcated fibrous layer, the flaccid type shows loose, irregularly arranged connective tissue in the fibrous layer which merges into the synovial layer of the joint capsule. The morphology of the intermediate type corresponds to an intermediate stage between the former two types. In the fibrous layer of the joint capsules three different types of sensory nerve endings were observed: free nerve endings, Ruffini corpuscles and lamellated corpuscles. The free nerve endings are supplied by myelinated afferent axons (1-2 microns in diameter); the terminal thickenings of which are incompletely surrounded by a terminal Schwann cell. Ruffini corpuscles are present in three different varieties: small corpuscles without a perineural capsule predominantly within the flaccid part of the capsule; slightly larger corpuscles with an incomplete perineural capsule and large corpuscles resembling Golgi tendon organs which predominantly occur in the rigid parts of the capsule. The afferent myelinated axons measure 2-4 microns in diameter. The lamellated corpuscles show two variants: small corpuscles with a 2 to 4-layered perineural capsule in the rigid parts of the joint capsules and large corpuscles with two longitudinal clefts of the inner core in the flaccid parts. Both types are supplied by myelinated axons of 3-5 microns in diameter. Thus, in the fibrous layer of the rigid type of joint capsules large Ruffini and small lamellated corpuscles predominate, whereas the fibrous layer of the flaccid type coincides with small Ruffini and large lamellated corpuscles. The present data, therefore, corroborate the concept that the morphology of mechanoreceptors depends upon the texture of the surrounding connective tissue. PMID:3605642

Strasmann, T; Halata, Z; Loo, S K



On the identification of sensory information from mixed nerves by using single-channel cuff electrodes  

Microsoft Academic Search

BACKGROUND: Several groups have shown that the performance of motor neuroprostheses can be significantly improved by detecting specific sensory events related to the ongoing motor task (e.g., the slippage of an object during grasping). Algorithms have been developed to achieve this goal by processing electroneurographic (ENG) afferent signals recorded by using single-channel cuff electrodes. However, no efforts have been made

Stanisa Raspopovic; Jacopo Carpaneto; Esther Udina; Xavier Navarro; Silvestro Micera



Influence of antagonist sensory and sympathetic nerves on smooth muscle cell differentiation in hypercholesterolemic rat.  


The effect of sympathectomy and sensory denervation on vascular smooth muscle cell (SMC) differentiation was investigated in hypercholesterolemic rats. Newborn rats received injections of guanethidine, capsaicin or both for denervations. Shams received injections of vehicles. The four groups were fed 1% cholesterol diet for 3 months. Intact normocholesterolemic rats were also exploited. Serum total cholesterol and systolic blood pressure (SBP) were measured. Lipid presence in the arterial wall was shown by Red-Oil-O staining. Catecholamine- and CGRP-containing fibres, vimentin and the adult SMC markers alpha-SMC-actin, desmin and h-caldesmon were analysed in abdominal aorta by western blot and confocal microscope. The sympathetic (catecholamine) fibres and SBP increased after sensory denervation while the sensory (CGRP) fibres increased and SBP decreased after sympathectomy. SBP was not changed after double denervation. Total cholesterol increased in sham and rose further after sympathectomy. Vimentin and the three adult SMC markers were not influenced by hypercholesterolemia. However, in the sympathectomized aorta, vimentin increased, desmin did not change, whereas alpha-SMC-actin and h-caldesmon decreased. In the sensory-denervated aorta, vimentin decreased, desmin increased, alpha-SMC-actin did not change and h-caldesmon decreased but less than in sympathectomized aorta. In the doubly denervated aorta, vimentin did not change and the three adult SMC markers decreased, although less than in sympathectomized aorta for alpha-SMC-actin and h-caldesmon. Thickened intima was identified by Red-Oil-O staining in the sympathectomized and (less remarkably) doubly denervated aortas containing SMCs not fully dedifferentiated. Our findings suggest that sympathectomy induces intimal thickening and favours SMC dedifferentiation, whereas sensory denervation favours SMC differentiation. PMID:20181536

Hachani, Rafik; Dab, Houcine; Sakly, Mohsen; Vicaut, Eric; Callebert, Jacques; Sercombe, Richard; Kacem, Kamel



Target-specific innervation by autonomic and sensory nerve fibers in hairy fetal skin transplanted into the anterior eye chamber of adult rat  

Microsoft Academic Search

Pieces of hairy skin tissue of fetal rat were transplanted into the anterior eye chamber of adult rats. The ability of autonomic and sensory nerve fibers from the host iris to innervate the grafted skin tissue was immunohistochemically and enzyme-histochemically examined using antisera against tyrosine hydroxylase (TH), substance P (SP), calcitonin gene-related peptide (CGRP) and vasoactive intestinal peptide (VIP), and

Norito Katoh; Shuichi Ueda; Yasuhiro Matsumoto; Saburo Kishimoto; Hirokazu Yasuno; Mitsuhiro Kawata



Lumbar 5 ventral root transection-induced upregulation of nerve growth factor in sensory neurons and their target tissues: a mechanism in neuropathic pain  

Microsoft Academic Search

We have previously demonstrated that profound and persistent neuropathic pain as displayed by mechanical and cold allodynia and thermal hyperalgesia can be produced by a lumbar 5 ventral root transection (L5 VRT) model in adult rats in which only the motor nerve fibers were injured without axotomy of sensory neurons. However, the underlying mechanisms remain to be determined. In this

Li Li; Cory J Xian; Jin-Hua Zhong; Xin-Fu Zhou



Best1 is a gene regulated by nerve injury and required for Ca2+-activated Cl- current expression in axotomized sensory neurons.  


We investigated the molecular determinants of Ca(2+)-activated chloride current (CaCC) expressed in adult sensory neurons after a nerve injury. Dorsal root ganglia express the transcripts of three gene families known to induce CaCCs in heterologous systems: bestrophin, tweety, and TMEM16. We found with quantitative transcriptional analysis and in situ hybridization that nerve injury induced upregulation of solely bestrophin-1 transcripts in sensory neurons. Gene screening with RNA interference in single neurons demonstrated that mouse Best1 is required for the expression of CaCC in injured sensory neurons. Transfecting injured sensory neurons with bestrophin-1 mutants inhibited endogenous CaCC. Exogenous expression of the fusion protein green fluorescent protein-Bestrophin-1 in naive neurons demonstrated a plasma membrane localization of the protein that generates a CaCC with biophysical and pharmacological properties similar to endogenous CaCC. Our data suggest that Best1 belongs to a group of genes upregulated by nerve injury and supports functional CaCC expression in injured sensory neurons. PMID:19675239

Boudes, Mathieu; Sar, Chamroeun; Menigoz, Aurélie; Hilaire, Cécile; Péquignot, Marie O; Kozlenkov, Alexei; Marmorstein, Alan; Carroll, Patrick; Valmier, Jean; Scamps, Frédérique



Experimental Autoimmune Model of Nerve Growth Factor Deprivation: Effects on Developing Peripheral Sympathetic and Sensory Neurons  

Microsoft Academic Search

An experimental autoimmune model of nerve growth factor (NGF) deprivation has been used to assess the role of NGF in the development of various cell types in the nervous system. Adult rats immunized with 2.5S mouse NGF in complete Freund's adjuvant produced antibodies that crossreacted with their own NGF and that were transferred in utero to the fetus and in

Pamela Dolkart Gorin; Eugene M. Johnson



Shock wave application to rat skin induces degeneration and reinnervation of sensory nerve fibres  

Microsoft Academic Search

There have been several reports on the use of extracorporeal shock waves in the treatment of pseudarthrosis, calcifying tendinitis, and tendinopathies of the elbow. However, the pathomechanism of pain relief has not been clarified. To investigate the analgesic properties of shock wave application, we analyzed whether it produces morphologic changes in cutaneous nerve fibres. In normal rat skin, the epidermis

Seiji Ohtori; Gen Inoue; Chikato Mannoji; Takashi Saisu; Kenji Takahashi; Shigeru Mitsuhashi; Yuichi Wada; Kazuhisa Takahashi; Masatsune Yamagata; Hideshige Moriya



Studies of peripheral sensory nerves in paclitaxel-induced painful peripheral neuropathy: Evidence for mitochondrial dysfunction  

Microsoft Academic Search

Paclitaxel chemotherapy frequently induces neuropathic pain during and often persisting after therapy. The mechanisms responsible for this pain are unknown. Using a rat model of paclitaxel-induced painful peripheral neuropathy, we have performed studies to search for peripheral nerve pathology. Paclitaxel-induced mechano-allodynia and mechano-hyperalgesia were evident after a short delay, peaked at day 27 and finally resolved on day 155. Paclitaxel-

Sarah J. L. Flatters; Gary J. Bennett



Apoptotic cascade of neurons in the subcortical sensory relay nuclei following the neonatal infraorbital nerve transection  

Microsoft Academic Search

A terminal transferase-mediated dUTP nick end labeling (TUNEL) method was utilized for detection of neuronal death in the subcortical relay nuclei of the trigeminosensory system following the infraorbital nerve transection in newborn rats. At 18–24 h after injury, numerous TUNEL-positive profiles were found within the ventroposteromedial thalamic nucleus (VPM) contralateral to the injury, whereas the VPM on the ipsilateral side

Tomosada Sugimoto; Chun Xiao; Akihiro Takeyama; Yi-Fen He; Teruko Takano-Yamamoto; Hiroyuki Ichikawa



The effects of acute and chronic lipopolysaccharide infusion in rats on the efferent function of sensory nerves in the isolated mesenteric arterial bed.  


Capsaicin-sensitive sensory neurons are stimulated by noxious stimuli, and may be activated in endotoxaemia. The present study investigated the acute and chronic effects of lipopolysaccharide upon the efferent function of these nerves. Conscious rats received infusion (i.v.) of lipopolysaccharide (150 microg kg(-1) h(-1)) or saline for 2 or 24 h. Following infusion, animals were killed and the mesenteric arterial bed isolated and perfused with Krebs' solution. Electrical field stimulation of capsaicin-sensitive sensory nerves was investigated. Postjunctional mechanisms of sensory neurotransmission were examined using calcitonin gene-related peptide, and endothelial and smooth muscle function assessed using acetylcholine and sodium nitroprusside, respectively. All preparations exhibited dose dependency to the agonists, and frequency dependency to electrical field stimulation. No significant differences were observed between the four groups (2-h saline, 24-h saline, 2-h lipopolysaccharide and 24-h lipopolysaccharide) with regard to responses to electrical field stimulation, acetylcholine, sodium nitroprusside or calcitonin gene-related peptide. Thus, the efferent function of capsaicin-sensitive sensory nerves is unaltered in the isolated mesenteric arterial bed prepared ex vivo from rats receiving lipopolysaccharide, either acutely (2 h) or chronically (24 h). PMID:12963421

Farmer, Matthew R; Gardiner, Sheila M; Ralevic, Vera



Sensory nerve conduction in the human spinal cord: epidural recordings made during scoliosis surgery.  

PubMed Central

This report describes the waveform and properties of somatosensory evoked potentials recorded from various levels of the human spinal cord, with electrodes inserted into the epidural space and the stimulus delivered to the posterior tibial nerve at the knee. The object was to provide a means of monitoring spinal cord function during surgery for the correction of spinal deformities. The responses could be resolved into at least three components with different activation thresholds and different conduction velocities within the spinal cord (45-80 m/s approximately). The findings are in accord with recent studies, suggesting that the fast activity may be conducted in the dorsal spinocerebellar tract and the slower waves in the posterior columns.

Jones, S J; Edgar, M A; Ransford, A O



Clinical utility of tibial motor and sensory nerve conduction studies with motor recording from the flexor hallucis brevis: a methodological and reliability study  

PubMed Central

Background Standard tibial motor nerve conduction measures are established with recording from the abductor hallucis. This technique is often technically challenging and clinicians have difficulty interpreting the information particularly in the short segment needed to assess focal tibial nerve entrapment at the medial ankle as occurs in posterior tarsal tunnel syndrome. The flexor hallucis brevis (FHB) has been described as an alternative site for recording tibial nerve function in those with posterior tarsal tunnel syndrome. Normative data has not been established for this technique. This pilot study describes the technique in detail. In addition we provide reference values for medial and lateral plantar orthodromic sensory measures and assessed intrarater reliability for all measures. Methods Eighty healthy female participants took part, and 39 returned for serial testing at 4 time points. Mean values ± SD were recorded for nerve conduction measures, and coefficient of variation as well as intraclass correlation coefficients (ICC) were calculated. Results Motor latency, amplitude and velocity values for the FHB were 4.1 ± 0.9 msec, 8.0 ± 3.0 mV and 45.6 ± 3.4 m/s, respectively. Sensory latencies, amplitudes, and velocities, respectively, were 2.8 ± 0.3 msec, 26.7 ± 10.1 ?V, and 41.4 ± 3.5 m/s for the medial plantar nerve and 3.2 ± 0.5 msec, 13.3 ± 4.7 ?V, and 44.3 ± 4.0 msec for the lateral plantar nerve. All values demonstrated significant ICC values (P ? 0.007). Conclusion Motor recording from the FHB provides technically clear waveforms that allow for an improved ability to assess tibial nerve function in the short segments used to assess tarsal tunnel syndrome. The reported means will begin to establish normal values for this technique.



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  

Microsoft Academic Search

.  ?Action potentials and electrotonic responses to 300-ms depolarizing and hyperpolarizing currents for human motor and sensory\\u000a myelinated nerve fibres have been simulated on the basis of double cable models. The effects of blocked nodal or internodal\\u000a potassium (fast or slow) channels on the fibre action potentials, early and late adaptations to 30-ms suprathreshold slowly\\u000a increasing depolarizing stimuli have been examined.

D. I. Stephanova; K. Mileva



Nerve conduits for nerve reconstruction  

Microsoft Academic Search

Although autogenous nerve grafting remains the gold standard for repair of peripheral nerve defects, the use of various conduits can be a substitute provided these conduits meet the above-mentioned prerequisites. For the moment, autogenous vein grafts or denatured muscle grafts can be used to bridge short defects, especially in distal sensory nerves. Incorporation of muscle into a vein graft expands

Huan Wang; William C. Lineaweaver



Exogenous nerve growth factor attenuates opioid-induced inhibition of voltage-activated Ba2+ currents in rat sensory neurons.  


Nerve growth factor (NGF) promotes the survival of embryonic sensory neurons and maintains the phenotypic characteristics of primary nociceptive neurons postnatally. NGF also contributes to nociceptor activation and hyperalgesia during inflammatory pain states. The purpose of this study was to determine whether NGF might have an additional pronociceptive action by interfering with opioid-mediated analgesia in primary nociceptive neurons. Sensory neurons were isolated from the dorsal root ganglia of weanling rats and kept in standard culture conditions either with or without exogenous NGF (50 ng/ml). Currents through voltage-gated calcium channels were recorded from individual neurons using the whole cell patch clamp technique with Ba(2+) as the charge carrier (I(Ba)). The micro-opioid agonist fentanyl (1 microM) and the GABA(B) agonist baclofen (50 microM) were used to test G protein-dependent inhibition of I(Ba). Fentanyl inhibited I(Ba) by an average of 38+/-4% in untreated cells vs. 25+/-2% in NGF-treated cells (P<0.01). NGF had no effect on I(Ba) current magnitude or kinetics. The NGF-induced attenuation of opioid action was observed as early as 4 h after exposure, but was not seen when NGF was applied by bath perfusion for up to 40 min, suggesting that the effect was not mediated by a rapid phosphorylation event. The effect of NGF was prevented by K-252a (100 nM), an inhibitor of TrkA autophosphorylation. Baclofen-induced inhibition of I(Ba), on the other hand, was not affected by NGF treatment, suggesting that NGF modulation of opioid-mediated inhibition occurred upstream from the G protein. This was supported by the finding that GTP-gamma-S, an agonist independent G protein activator, inhibited I(Ba) similarly in both untreated and NGF treated cells. The results show that NGF selectively attenuated opioid-mediated inhibition of I(Ba) via TrkA receptor activation, possibly by altering opioid receptor function. PMID:15120862

McDowell, T S



Sensory and autonomic nerve changes in the monosodium glutamate-treated rat: a model of type II diabetes.  


Rats that had been injected with monosodium glutamate (MSG) neonatally were studied for up to 70 weeks and compared with age-matched control rats to study changes in glucose tolerance and in sympathetic and sensory nerves. At 61 and 65 weeks of age, there were significant differences in glucose tolerance between the MSG and control groups, and the MSG group had raised fasting blood glucose. These changes were not associated with changes in the number of beta-cells in the islets of Langerhans. In addition, the diabetic MSG-treated rats had central obesity and cataracts. Hypoalgesia to thermal stimuli was present in MSG-treated rats as early as 6 weeks and persisted at 70 weeks. However, no differences were observed in the distribution of substance P, the neurokinin-1 receptor or calcitonin gene-related peptide in the dorsal horn of L3-L5 at this age (70 weeks). Diabetic MSG-treated animals at 65 and 70 weeks of age had significantly reduced noradrenaline concentrations in the heart, tail artery and ileum, while concentrations in the adrenal gland and corpus cavernosum were significantly increased. There was also a significant increase in adrenal adrenaline, dopamine and serotonin, largely attributable to changes in weight of the adrenal gland in the MSG-treated animals. The results indicate that MSG-treated animals develop a form of type II diabetes by about 60 weeks of age, and that there are significant changes in amine levels in various tissues associated with these developments. PMID:17911358

Morrison, John F B; Shehab, Safa; Sheen, Rajan; Dhanasekaran, Subramanian; Shaffiullah, Mohammed; Mensah-Brown, Eric



Sensory neuronopathy; a case report and a review of the role of ganglion nerve biopsy in diagnosis.  


Dorsal root ganglionopathies present with sensory ataxia, areflexia and asymmetrical positive and negative sensory phenomenon of both limb often with trigeminal involvement. There may be associated Adie's pupil(1) Despite their classical features and relatively discrete list of causes they can be difficult to definitively diagnose. We present such a case in whom biopsy of the thoracic dorsal root ganglion resulted in identifying of continued inflammation despite normal haematological makers thereby altering subsequent management. A 54 year old telecommunications officer with a background of anterior uveitis presented with a 3 year history of progressive altered sensation of his right hand and a 2 month history of altered sensation of the right side of his face including oral mucosa. There was unilateral facial sensory loss to pin prick, right upper limb pseudoathetosis, hyperaesthesia of C5 to C8 and impaired proprioception to wrist. He was hyporeflexic throughout. He was on no regular medication, was a lifelong smoker, drank minimal alcohol and denied any family history. His immunology demonstrated a positive cANCA at 7 (0-5) and positive ENA (anti-La ). He had normal inflammatory markers, vitamins B6 and B12, homocysteine, methylmalonic acid, folate, serial antineuronal antibodies, HIV, angiotensin converting enzyme, phytanic acid, protein electrophoresis, chest X-ray, contrast MRI imaging of brain, cervical spine and brachial plexus. He had 3 large volume CSF analyses with normal cell count, protein, glucose ratio, and negative oligoclonal banding and cytology. His neurophysiology was positive for a possible right sided ganglionopathy. There was an associated parathyroid adenoma which was removed. Repeat CT of chest abdomen and pelvis demonstrated a pulmonary nodule with no change noted on serial images and follow up FDG-PET at 2 years was normal. He was initially treated with IV methylprednisolone and oral taper. He also received immunoglobulin. There was further clinical deterioration so was initiated. Despite these immunosuppressive therapies he continued to clinically deteriorate with distal mild weakness, areflexia and worsening proprioceptive deficits to his left wrist and MTP joints bilaterally. Inflammatory markers were persistently normal throughout. A radial nerve biopsy demonstrated axonal loss with no evidence of active inflammation. It was therefore unclear whether his ongoing deterioration was related to neurodegeneration or ongoing inflammation. A thoracic DRG biopsy was therefore undertaken. This demonstrated florid macrophage-mediated neuropathy with frequent myelin digestion. Due to evidence of an active inflammatory process he was treated with pulsed IV cyclophosphamide to a total of 10g with stabilisation of his limb signs. He is now maintained on Azathioprine. Our case demonstrates the important information that can be gained from DRG biopsy in those with clinical deterioration despite immunosuppressive treatment. DRG is invasive, however reports demonstrate high diagnostic yield and low post-operative complication rates when thoracic ganglions are biopsied.(2.) PMID:24108992

Waddell, Briony; Farmer, Simon; Lunn, Mike; O'Riordan, Jonathon I



The contribution of capsaicin-sensitive sensory nerves to xylene-induced visceral pain in conscious, freely moving rats  

Microsoft Academic Search

1.Intravesical instillation of xylene (10–100%, dissolved in silicone oil) through a catheter implanted into the bladder of conscious, freely-moving rats produced behavioural effects (licking of lower abdomen or perineal region) suggestive of intense visceral pain, not mimicked by topical application of the irritant on the urethral outlet.2.The xylene-induced visceral pain was prevented, to the same extent, by systemic desensitization to

Luigi Abelli; Bruno Conte; Vincenzo Somma; Carlo Alberto Maggi; Sandro Giuliani; Pierangelo Geppetti; Massimo Alessandri; Elvar Theodorsson; Alberto Meli



Static Electricity Desensitizing Device.  

National Technical Information Service (NTIS)

The device desensitizes electrically fired squibs, detonators, or initiators to stray currents of electricity, particularly those arising from the accumulation of static electrical charges. The device provides an arc gap so that accumulated static electri...

N. P. Williams



Experimental desensitization of phobia  

Microsoft Academic Search

24 snake phobic Ss participated in an experimental investigation of systematic desensitization therapy. Ss who experience desensitization showed a greater reduction in phobic behavior (as measured by avoidance behavior in the presence of the phobic object and self-ratings) than did nonparticipating controls. Ss tended to hold or increase therapy gains at a 6-month follow-up evaluation, and gave no evidence of

Peter J. Lang; A. David Lazovik



A Catecholaminergic Sensory Neuron Phenotype in Cranial Derivatives of the Neural Crest: Regulation by Cell Aggregation and Nerve Growth Factor  

Microsoft Academic Search

Tyrosine hydroxylase (TH) is transiently detectable in cells distributed throughout cranial sensory ganglia during early stages of gangliogenesis (embryonic day (E) 10.5-15.51. Although TH cells appear in embryonic ganglia of both neural crest and placode origin, mature cranial sensory neurons that express catecholaminergic properties are restricted to placode derivatives. The mechanism(s) underlying the loss of TH expression in crest-derived sensory

David M. Katz



Interaction between selective cyclooxygenase inhibitors and capsaicin-sensitive afferent sensory nerves in pathogenesis of stress-induced gastric lesions. Role of oxidative stress.  


Gastric microcirculation plays an important role in the maintenance of the mucosal gastric integrity and the mechanism of injury as well as providing protection to the gastric mucosa. Disturbances in the blood perfusion, through the microcapillaries within the gastric mucosa may result in the formation of mucosal damage. Acute gastric mucosal lesions constitute an important clinical problem. Originally, one of the essential component of maintaining the gastric mucosal integrity was the biosynthesis of prostaglandins (PGs), an issue that has captured the attention of numerous investigations. PGs form due to the activity of cyclooxygenase (COX), an enzyme which is divided into 2 isoforms: constitutive (COX-1) and inducible (COX-2) ones. The inhibition of COX-1 by SC-560, or COX-2 by rofecoxib, reduces gastric blood flow (GBF) and impairs gastric mucosal integrity. Another detrimental effect on the gastric mucosal barrier results from the ablation of sensory afferent nerves by neurotoxic doses of capsaicin. Functional ablation of the sensory afferent nerves by capsaicin attenuates GBF and also renders the gastric mucosa more susceptible to gastric mucosal damage induced by ethanol, aspirin and stress. However, the role of reactive oxygen species (ROS) in the interaction between COX specific inhibitors and afferent sensory nerves has not been extensively studied. The aim of our present study was to determine the participation of ROS in pathogenesis of stress-induced gastric lesions in rats administered with SC-560 or rofecoxib, with or without ablation of the sensory afferent nerves. ROS were estimated by measuring the gastric mucosal tissue level of MDA and 4-HNE, the products of lipid peroxidation by ROS as well as the SOD activity and reduced glutathione (GSH) levels, both considered to be scavengers of ROS. It was demonstrated that exposure to 3.5 h of WRS resulted in gastric lesions, causing a significant increase of MDA and 4-HNE in the gastric mucosa, accompanied by a decrease of SOD activity and mucosal GSH level. Pretreatment with COX-1 and COX-2 inhibitors (SC-560 and rofecoxib, respectively) aggravated the number of gastric lesions, decreased GBF, attenuated GSH level without further significant changes in MDA and 4-HNE tissue levels and SOD activity. Furthermore, the capsaicin--nactivation of sensory nerves resulted in exaggeration of gastric mucosal damage induced by WRS and this was further augmented by rofecoxib. We conclude that oxidative stress, as reflected by an increase of MDA and 4-HNE tissue concentrations (an index of lipid peroxidation), as well as decrease of SOD activity and the fall in GSH tissue level, may play an important role in the mechanism of interaction between the inhibition of COX activity and afferent sensory nerves releasing vasoactive neuropeptides. This is supported by the fact that the addition of specific COX-1 or COX-2 inhibitors to animals with capsaicin denervation led to exacerbation of gastric lesions, and further fall in the antioxidizing status of gastric mucosa exposed to stress. PMID:22653901

Kwiecien, S; Konturek, P C; Sliwowski, Z; Mitis-Musiol, M; Pawlik, M W; Brzozowski, B; Jasnos, K; Magierowski, M; Konturek, S J; Brzozowski, T



Induction of TRPV1 desensitization by a biased receptor agonist.  


Selective suppression of hyperactive sensory neurons is an attractive strategy for managing pathological pain. Blocking Na(+) channels to eliminate action potentials and desensitizing transduction channels can both reduce sensory neuron excitability. The novel synthetic vanilloid ligand cap-ET preserves agonist activation of intracellular Ca(2+) signals and large organic cation transport but loses effective electric current induction. Cap-ET can therefore be used to deliver the membrane impermeable Na(+) channel blocker QX-314 to substantially inhibit voltage-activated Na(+) currents. We explored, besides facilitating entry of organic cationic therapeutics, whether cap-ET can also produce receptor desensitization similar to the natural agonist capsaicin. Using the YO-PRO-1 based fluorescent dye uptake assay, we found that cap-ET effectively triggered Ca(2+) dependent desensitization of TRPV1 when the receptor was pre-sensitized with the surrogate oxidative chemical phenylarsine oxide (PAO), suggesting an alternative use of permanently charged cationic capsaicinoids in differential neuronal silencing. PMID:21829089

Wang, Elaine E; Li, Hui; Wang, Shu; Chuang, Alexander Y; Chuang, Huai-hu



Persistent modification of synaptic interactions between sensory and motor nerve cells following discrete lesions in the central nervous system of the leech  

PubMed Central

We have examined changes that develop in the synaptic interactions of sensory and motor nerve cells following surgical lesions to the central nervous system of the leech. In one type of operation an individual ganglion was isolated from the rest of the nervous system by severing all the incoming and outgoing fibres. During the next few weeks, marked changes appeared in synaptic interactions. 1. In chronically isolated ganglia inhibitory potentials were recorded in the motoneurone which raises the skin into ridges (the AE cell) following impulses in sensory neurones that respond to pressure (P) or noxious (N) stimuli. In contrast the same AE cell in ganglia taken from normal animals shows excitatory synaptic potentials when the P or N sensory cells are stimulated. 2. Another altered synaptic interaction in ganglia isolated by lesions was that between sensory cells responding to touch and a motoneurone that supplies longitudinal muscles (L cell). Instead of the pure, electrical coupling potential seen normally, a large, additional chemically mediated excitatory potential was also apparent. 3. Some of the changes in synaptic interactions were not restricted to synapses within the isolated ganglion, but appeared gradually over the following year in successive ganglia along the length of the ventral nerve cord. 4. Indirect evidence suggests that the altered synaptic potentials that became conspicuous after operations are also present but smaller and obscured in normal animals. 5. It is concluded that some synapses in the leech nervous system are more readily changed than others by cutting the connectives. Furthermore, these changes influence in a predictable manner the way in which the animal behaves in response to mechanical stimuli.

Jansen, J. K. S.; Muller, K. J.; Nicholls, J. G.



Structural determinant of TRPV1 desensitization interacts with calmodulin  

Microsoft Academic Search

The capsaicin receptor, TRPV1 (VR1), is a sensory neuron-specific ion channel that serves as a polymodal detector of pain-producing chemical and physical stimuli. Extracellular Ca2+-dependent desensitization of TRPV1 observed in patch-clamp experiments when using both heterologous expression systems and native sensory ganglia is thought to be one mechanism underlying the paradoxical effectiveness of capsaicin as an analgesic therapy. Here, we

Mitsuko Numazaki; Tomoko Tominaga; Kumiko Takeuchi; Namie Murayama; Hidenori Toyooka; Makoto Tominaga



Adhesiolysis and targeted steroid\\/local anesthetic injection during epiduroscopy alleviates pain and reduces sensory nerve dysfunction in patients with chronic sciatica  

Microsoft Academic Search

Purpose  The aim of this study was to evaluate the effect of adhesiolysis followed by the injection of steroid and local anesthetic\\u000a during epiduroscopy on sensory nerve function, pain, and functional disability in patients with chronic sciatica.\\u000a \\u000a \\u000a \\u000a Methods  Epidural adhesiolysis, using epiduroscopy, followed by the injection of steroid and local anesthetic, was scheduled in 19\\u000a patients with chronic sciatica refractory to lumbar

Tetsuya Sakai; Hiroshi Aoki; Minoru Hojo; Masafumi Takada; Hiroaki Murata; Koji Sumikawa



Nerve Injuries  


... educated." After the nerve has recovered, sensory re-education may be needed to improve feeling to the hand or finger. This involves physician therapy and the appropriate therapy based on the nature of the injury will be recommended ...


Nerve conduction  

MedlinePLUS Videos and Cool Tools

... fascicles) that contain hundreds of individual nerve fibers (neurons). Neurons consist of dendrites, axon, and cell body. The ... tree-like structures that receive signals from other neurons and from special sensory cells that sense the ...


Nerve Growth Factor and Semaphorin 3A Signaling Pathways Interact in Regulating Sensory Neuronal Growth Cone Motility  

Microsoft Academic Search

Neurotrophins and semaphorin 3A are present along pathways and in targets of developing axons of dorsal root ganglion (DRG) sensory neurons. Growth cones of sensory axons are probably regulated by interaction of cytoplasmic signaling trig- gered coincidentally by both types of guidance molecules. We investigated the in vitro interactions of neurotrophins and semaphorin 3A (Sema3A) in modulating growth cone behaviors

Vassil D. Dontchev; Paul C. Letourneau



Vascularization of the dorsal root ganglia and peripheral nerve of the mouse: Implications for chemical-induced peripheral sensory neuropathies  

Microsoft Academic Search

Although a variety of industrial chemicals, as well as several chemotherapeutic agents used to treat cancer or HIV, preferentially induce a peripheral sensory neuropathy what remains unclear is why these agents induce a sensory vs. a motor or mixed neuropathy. Previous studies have shown that the endothelial cells that vascularize the dorsal root ganglion (DRG), which houses the primary afferent

Juan M Jimenez-Andrade; Monica B Herrera; Joseph R Ghilardi; Marina Vardanyan; Ohannes K Melemedjian; Patrick W Mantyh



Local administration of neurotrophic growth factor in subcutaneous silicon chambers enhances the regeneration of the sensory component of the rat sciatic nerve.  


An experimental model for local administration of neurotrophic growth factor (NGF) in peripheral nerve lesions is tested. The model consists of a subcutaneous reservoir connected to the sciatic nerve neurorrhaphy. The right sciatic nerves were exposed, severed, and repaired at a level 1.5 cm proximal to their trifurcation. Then, a dome-shaped silicone reservoir connected to the proximal end of a silicone tube was placed subcutaneously in the dorsum of the experimental animal. The distal end of the connecting tube was located in the nerve neurorrhaphy. Two experimental groups were made: Group A (n = 90) received daily doses of a solution containing NGF-7S during the first 4 weeks after surgery and a single weekly dose thereafter. Within this group, three subgroups of 30 rats each were made: A-4 sacrificed 4 weeks after surgery, A-8 sacrificed after 8 weeks, and A-12 after 12 weeks. Group B (n = 90) received the same vehicle solution without NGF under the same schedule and volume as in Group A. Three subgroups were also made as in Group A depending on the survival period. In order to locate the neurons in the dorsal root ganglia, the retrograde tracer horseradish peroxidase was administered at the proximal stump of the sciatic nerve (tibialis branch), which was severed 1 cm distal to the sciatic trifurcation. In respect of the nonoperated side, the percentage between the number of dorsal root ganglia neurons in the NGF-treated group was significantly higher than in the control group (P < 0.001). These results demonstrate that percutaneous administration of multiple doses of NGF in this model enhances sensory nerve regeneration after sciatic lesions evaluated by horseradish peroxidase labeling of dorsal root ganglia neurons. PMID:10469442

Santos, X; Rodrigo, J; Hontanilla, B; Bilbao, G



Involvement of sensory nerves and immune cells in osteophyte formation in the ankle joint of adjuvant arthritic rats  

Microsoft Academic Search

To study the mechanism of osteophyte formation in the ankle joints of adjuvant arthritic (AA) rats, the localization of peripheral nerves and immune cells in the synovia were investigated in both axotomized AA rats, whose sciatic nerves were resected before adjuvant injection, and sham-operated ones, using immunohistochemistry for low-affinity nerve growth factor receptor (p75NGFR), growth-associated protein (GAP)-43, calcitonin gene-related peptide

Zhou Wu; Kengo Nagata; Tadahiko Iijima



Activation of Endothelin-A Receptors Contributes to Angiotensin-Induced Suppression of Renal Sensory Nerve Activation  

Microsoft Academic Search

Activation of renal mechanosensory nerves is enhanced by a high-sodium diet and suppressed by a low-sodium diet. Angiotensin (Ang) II and endothelin (ET)-1 each contributes to the impaired responsiveness of renal mechanosen- sory nerves in a low-sodium diet. We examined whether stimulation of ETA receptors (Rs) contributes to Ang II-induced suppression of the responsiveness of renal mechanosensory nerves. In anesthetized

Ulla C. Kopp; Michael Z. Cicha; Lori A. Smith



A low-affinity antagonist reveals saturation and desensitization in mature synapses in the auditory brain stem.  


Postsynaptic receptor desensitization has been observed to contribute to depression in immature synapses. However, it is not clear whether desensitization persists and causes depression in mature synapses. We investigate this issue at the endbulb of Held, the synapse made by auditory nerve (AN) fibers onto bushy cells (BCs) of the anteroventral cochlear nucleus, where depression could influence the processing of sound information. Experiments using cyclothiazide (CTZ) have implicated desensitization in endbulbs from postnatal day 16 (P16) to P21 mice, but application of ?-D-glutamylglycine (DGG) did not reveal desensitization in endbulbs >P22. To reconcile these findings, we have studied the effects of both CTZ and DGG on endbulbs from P5 to P40 CBA/CaJ mice. In paired-pulse protocols, both CTZ and DGG reduced depression in all ages at intervals <10 ms, consistent with their effects preventing desensitization. However, DGG increased depression at intervals >20 ms, consistent with DGG's use to prevent saturation. DGG application revealed receptor saturation even under conditions of very low release probability. Preventing desensitization by CTZ occluded the effects of DGG on desensitization and revealed the effects of saturation at short intervals. We developed an approach to separate DGG's effect on saturation from its effect on desensitization, which showed that desensitization has an impact during bursts of auditory nerve activity. Dynamic-clamp experiments indicated that desensitization can reduce BC spike probability and increase latency and jitter. Thus desensitization may affect sound processing in the mature auditory system. PMID:20107122

Chanda, Soham; Xu-Friedman, Matthew A



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

PubMed Central

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.

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.



Mechanisms of aspirin desensitization.  


Aspirin-exacerbated respiratory disease is a clinical syndrome characterized by severe, persistent asthma, hyperplastic eosinophilic sinusitis with nasal polyps, and reactions to aspirin and other nonsteroidal antiinflammatory drugs that preferentially inhibit cyclooxygenase 1. The mechanisms behind the therapeutic effects of aspirin desensitization remain poorly understood. Recent studies suggest that the clinical benefits may occur through direct inhibition of tyrosine kinases and the signal transducer and activator of transcription 6 signaling pathway, which results in inhibition of interleukin 4 production. In this article, the current understanding of the mechanisms of aspirin desensitization is reviewed and future areas of investigation are discussed. PMID:23639710

Burnett, Trever; Katial, Rohit; Alam, Rafeul



Motor and sensory re-innervation of the lung and heart after re-anastomosis of the cervical vagus nerve in rats  

PubMed Central

There is no study in the literature dealing with re-innervation of the cardiopulmonary vagus nerve after its transection followed by re-anastomosis. In the present study, we explored the bronchomotor, heart rate and respiratory responses in rats at 2, 3 and 6 months after re-anastomosis of one cervical vagus trunk. The conduction velocity of A, B and C waves was calculated in the compound vagal action potential. We searched for afferent vagal activities in phase with pulmonary inflation to assess the persistence of pulmonary stretch receptor (PSR) discharge in re-innervated lungs. In each animal, data from the stimulation or recording of one re-anastomosed vagus nerve were compared with those obtained in the contra-lateral intact one. Two and three months after surgery, the conduction velocities of A and B waves decreased, but recovery of conduction velocity was complete at 6 months. By contrast, the conduction velocity of the C wave did not change until 6 months, when it was doubled. The PSR activity was present in 50% of re-anastomosed vagus nerves at 2 and 3 months and in 75% at 6 months. Respiratory inhibition evoked by vagal stimulation was significantly weaker from the re-anastomosed than intact nerve at 2 but not 3 months. Vagal stimulation did not elicit cardiac slowing or bronchoconstriction 6 months after re-anastomosis. Our study demonstrates the capacity of pulmonary vagal sensory neurones to regenerate after axotomy followed by re-anastomosis, and the failure of the vagal efferents to re-innervate both the lungs and heart.

Bregeon, Fabienne; Alliez, Jean Roch; Hery, Geraldine; Marqueste, Tanguy; Ravailhe, Sylvie; Jammes, Yves



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


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

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



Spinal nerve lesion-induced mechanoallodynia and adrenergic sprouting in sensory ganglia are attenuated in interleukin-6 knockout mice  

Microsoft Academic Search

Tight ligation and transection of the L5 spinal nerve (SNL) gives rise to pain which is dependent upon activity in the sympathetic nervous system. It also results in novel adrenergic sympathetic innervation of the dorsal root ganglion (DRG) with the formation of pericellular axonal basket structures around some DRG neurons. Since the sympathetic sprouting and basket formation may represent an

Matt S. Ramer; Patricia G. Murphy; Peter M. Richardson; Mark A. Bisby



Activation of endothelin-a receptors contributes to angiotensin-induced suppression of renal sensory nerve activation.  


Activation of renal mechanosensory nerves is enhanced by a high-sodium diet and suppressed by a low-sodium diet. Angiotensin (Ang) II and endothelin (ET)-1 each contributes to the impaired responsiveness of renal mechanosensory nerves in a low-sodium diet. We examined whether stimulation of ETA receptors (Rs) contributes to Ang II-induced suppression of the responsiveness of renal mechanosensory nerves. In anesthetized rats fed a low-sodium diet, renal pelvic administration of the Ang type I receptor (AT1-R) antagonist losartan enhanced the afferent renal nerve activity (ARNA) response to increasing renal pelvic pressure 7.5 mm Hg from 7+/-2% to 15+/-2% and the prostaglandin (PG) E(2)-mediated substance P release from 0+/-1 to 8+/-1 pg/min. Adding the ETA-R antagonist BQ123 to the renal pelvic perfusate containing losartan did not produce any further enhancement of the ARNA response or PGE(2)-mediated release of substance P (17+/-3% and 8+/-1 pg/min). Likewise, renal pelvic administration of BQ123 and BQ123+losartan resulted in similar enhancements of the ARNA responses to increased renal pelvic pressure and PGE(2)-mediated substance P release. In high-sodium-diet rats, pelvic administration of Ang II reduced the ARNA response to increased renal pelvic pressure from 27+/-4% to 8+/-3% and the PGE(2)-mediated substance P release from 9+/-0 to 1+/-1 pg/min. Adding BQ123 to the renal pelvic perfusate containing Ang II restored the increases in ARNA and the PGE(2)-mediated substance P release toward control (27+/-6% and 7+/-1 pg/min). In conclusion, stimulation of ETA-R plays an important contributory role to the Ang II-mediated suppression of the activation of renal mechanosensory nerves in conditions of low-sodium diet. PMID:17060503

Kopp, Ulla C; Cicha, Michael Z; Smith, Lori A



Sensory Relearning in Peripheral Nerve Disorders of the Hand: A Web-Based Survey and Delphi Consensus Method  

Microsoft Academic Search

Sensory relearning (SR) first described in the 1970s by Wynn-Parry and Dellon has evolved over the last 20 years as a result of new insights into cortical plasticity. It has eluded precise definition, and a detailed description of its “key ingredients” is rarely documented in published studies investigating effectiveness.The purpose of this two-part study was to define SR and describe the

Christina Jerosch-Herold



Intradermal Injection of Capsaicin in Humans Produces Degeneration and Subsequent Reinnervation of Epidermal Nerve Fibers: Correlation with Sensory Function  

Microsoft Academic Search

fibers and the subepidermal neural plexus in capsaicin-treated skin, as indicated by the loss of immunoreactivity for PGP 9.5 and CGRP. The effect of capsaicin on dermal nerve fibers immunoreactive for SP was less obvious. Capsaicin decreased sensitivity to pain produced by sharp mechanical stimuli and nearly eliminated heat-evoked pain within the injected area. Limited reinnervation of the epidermis and

Donald A. Simone; Maria Nolano; Timothy Johnson; Gwen Wendelschafer-Crabb; William R. Kennedy



Tumor Necrosis Factor Induces Mechanical Allodynia after Spinal Nerve Ligation by Activation of p38 MAPK in Primary Sensory Neurons  

Microsoft Academic Search

Tumor necrosis factor- (TNF) is implicated in the initiation of neuropathic pain. In vitro, TNF activates p38 mitogen-activated kinase. Accord- ingly, we investigated whether TNF activates the p38 cascade in vivo to trigger pain behavior after spinal nerve ligation (SNL). Treatment starting 2 d before SNL with the TNF antagonist etanercept (1 mg, i.p., every third day) attenuated mechanical allodynia.

Maria Schafers; Camilla I. Svensson; Claudia Sommer; Linda S. Sorkin



Modelled temperature-dependent excitability behaviour of a single ranvier node for a human peripheral sensory nerve fibre  

Microsoft Academic Search

The objective of this study was to determine whether the Hodgkin–Huxley model for unmyelinated nerve fibres could be modified\\u000a to predict excitability behaviour at Ranvier nodes. Only the model parameters were modified to those of human, with the equations\\u000a left unaltered. A model of a single Ranvier node has been developed as part of a larger model to describe excitation

Jacoba E. Smit; Tania Hanekom; Johan J. Hanekom



Neurogenic inflammation, vascular permeability, and mast cells. Capsaicin desensitization fails to influence IgE-anti-DNP induced vascular permeability in rat airways.  


Mast cells and neuropeptide-containing nerves occur in close proximity throughout the mucosa. The vasodilation that characteristically occurs after mast cell mediator release in skin is dependent upon sensory nerve activation with neuropeptide release. It was therefore of interest to examine the relationship between antigen-induced mast cell activation, vascular permeability, and the influence of capsaicin-sensitive sensory nerves in the airways. To examine this question, capsaicin was administered systemically and the "desensitization" of the animals to topical capsaicin confirmed. Thereafer, capsaicin-desensitized animals were studied to see if mast cell mediator-induced vascular permeability was affected. Plasma protein extravasation (PPE) was induced in Sprague-Dawley rats by intratracheal infusion of capsaicin or by intratracheal infusion of mouse serum albumin-dinitrophenol (MSA-DNP) after passive sensitization with IgE-anti-DNP. Leaking vessels in the airways were localized by using Monastral blue B, a macromolecular tracer. In the trachea, leaking vessels were predominantly located in the anterior wall after capsaicin challenge and in the posterior wall after antigen challenge. PPE was quantified by preinjecting animals with 125I-labeled BSA and expressed as microliter of plasma deposited in the trachea, bronchi, lungs, and tracheobronchial lavage (TBL). Within one minute after challenge, concentrations of capsaicin greater than 10(-7) M significantly increased PPE in trachea and bronchial wall (+ 160% and + 175% above control, respectively, with 10(-5) M). PPE was also observed in the trachea and bronchi after antigen challenge in animals passively sensitized with IgE-anti-DNP (+ 200% and + 153%, respectively).(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2137314

Didier, A; Kowalski, M L; Jay, J; Kaliner, M A



Nerve growth factor acts through the TrkA receptor to protect sensory neurons from the damaging effects of the HIV-1 viral protein, Vpr.  


Distal sensory polyneuropathy (DSP) with associated neuropathic pain is the most common neurological disorder affecting patients with human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS). Viral protein R (Vpr) is a neurotoxic protein encoded by HIV-1 and secreted by infected macrophages. Vpr reduces neuronal viability, increases cytosolic calcium and membrane excitability of cultured dorsal root ganglion (DRG) sensory neurons, and is associated with mechanical allodynia in vivo. A clinical trial with HIV/AIDS patients demonstrated that nerve growth factor (NGF) reduced the severity of DSP-associated neuropathic pain, a problem linked to damage to small diameter, potentially NGF-responsive fibers. Herein, the actions of NGF were investigated in our Vpr model of DSP and we demonstrated that NGF significantly protected sensory neurons from the effects of Vpr. Footpads of immunodeficient Vpr transgenic (vpr/RAG1(-/-)) mice displayed allodynia (p<0.05), diminished epidermalinnervation (p<0.01) and reduced NGF mRNA expression (p<0.001) compared to immunodeficient (wildtype/RAG1(-/-)) littermate control mice. Compartmented cultures confirmed recombinant Vpr exposure to the DRG neuronal perikarya decreased distal neurite extension (p<0.01), whereas NGF exposure at these distal axons protected the DRG neurons from the Vpr-induced effect on their cell bodies. NGF prevented Vpr-induced attenuation of the phosphorylated glycogen synthase-3 axon extension pathway and tropomyosin-related kinase A (TrkA) receptor expression in DRG neurons (p<0.05) and it directly counteracted the cytosolic calcium burst caused by Vpr exposure to DRG neurons (p<0.01). TrkA receptor agonist indicated that NGFacted through the TrkA receptor to block the Vpr-mediated decrease in axon outgrowth in neonatal and adult rat and fetal human DRG neurons (p<0.05). Similarly, inhibiting the lower affinity NGF receptor, p75, blocked Vpr's effect on DRG neurons. Overall, NGF/TrkA signaling or p75 receptor inhibition protects somatic sensory neurons exposed to Vpr, thus laying the groundwork for potential therapeutic options for HIV/AIDS patients suffering from DSP. PMID:23912036

Webber, C A; Salame, J; Luu, G-L S; Acharjee, S; Ruangkittisakul, A; Martinez, J A; Jalali, H; Watts, R; Ballanyi, K; Guo, G F; Zochodne, D W; Power, C



Micturition reflex arc reconstruction including sensory and motor nerves after spinal cord injury: Urodynamic and electrophysiological responses  

PubMed Central

Objective To evaluate artificial reflex arcs for micturition using urodynamics and electrophysiological recordings. Design Sixteen beagles were equally and randomly divided into two groups. Methods In group A, anastomosis of the proximal end of the left L7 ventral root (VR) and distal end of the left S2 VR was performed, as well as anastomosis of the L7 dorsal root (DR) and S2 DR to reconstruct the sensory and the motor function of the bladder. In group B the proximal end of the left L7 VR and the distal end of the left S2 VR were anastomosed, while the left L7 DR was kept intact to reconstruct the motor function of the bladder. Outcome measures included electrophysiological testing and the urodynamic measures. In addition, we also monitored urinary infection rates. Results Stimulation to the left S2 DR in groups A and B both elevated the bladder pressure before and after the spinal lower motor neuron lesion. Single stimulation of the two groups both elicited evoked action potentials. Urinary infections occurred in group A (three occurrences) and in group B (eight occurrences) during the 3 months after the spinal lower motor neuron lesion. Conclusion Data showed that both reconstructive methods could induce bladder micturition and evoked action potentials. However, in group A the micturition response was better and the urinary infection rates were lower after the spinal lower motor neuron lesion. Thus, the artificial physiological reflex arc reconstruction method used in group A, with sensory input above the lesion, might provide a better alternative in clinical practice.

Ma, Jun; Sui, Tao; Zhu, YuCheng; Zhu, AiXiang; Wei, ZhongQing; Cao, Xiao Jian



The postnatal changes in the density of sensory nerve endings in the oral mucosa of the cat.  


The changes that occur in the distribution and density of the encapsulated endings and Merkel cell-neurite complexes of the lingual gingival and alveolar mucosa of the mandible of kittens from birth to 28 d of age were observed through the use of methylene blue vital staining. The distribution of encapsulated endings showed a tendency to increase over the total area of the mucosae, but Merkel cell-neurite complexes tended to group into bands across the gingivae. While the density of the nerve endings of the former showed a continuous increase over the time period from the day of birth, when they totalled 13/cm2, to the 28th d by which that figure had increased to 144/cm2, the latter showed no such marked increase, totalling only 35/cm2 and 50/cm2, respectively. Further observations were made of the ultrastructures of organized endings in adult cat. PMID:3400879

Tazaki, M; Sakada, S




PubMed Central

Current therapies for treating skeletal pain have significant limitations as available drugs (nonsteroidal anti-inflammatory drugs and opiates) have significant unwanted side effects. Targeting nerve growth factor or it's cognate receptor Tropomysin receptor kinase A (TrkA) has recently become an attractive target for inhibition of adult skeletal pain. Here we explore whether sustained administration of a selective small molecule Trk inhibitor that blocks TrkA, TrkB and TrkC kinase activity with nanomolar affinity reduces skeletal pain while allowing the maintenance of sensory and sympathetic neurons in the adult mouse. Twice-daily administration of a Trk inhibitor was begun 1 day post fracture and within 8 hours of acute administration fracture pain related behaviors were reduced by 50% without significant sedation, weight gain or inhibition of fracture healing. Following administration of the Trk inhibitor for 7 weeks, there was no significant decline in the density of unmyelinated, myelinated sensory or sympathetic nerve fibers, measures of acute thermal pain, acute mechanical pain, or general neuromuscular function. The present results suggest that sustained administration of a peripherally selective TrkA, B & C inhibitor significantly reduces skeletal pain without having any obvious detrimental effects on adult sensory and sympathetic nerve fibers or early fracture healing. As with any potential therapeutic advance, understanding whether the benefits of NGF blockade by ARRY-470 are associated with any risks or unexpected effects will be required to fully appreciate the patient populations that may benefit from this therapy.

Ghilardi, Joseph R.; Freeman, Katie T.; Jimenez-Andrade, Juan M.; Mantyh, William G.; Bloom, Aaron P.; Bouhana, Karyn S.; Trollinger, David; Winkler, James; Lee, Patrice; Andrews, Steven W.; Kuskowski, Michael A.; Mantyh, Patrick W.



Preferential Reinnervation of Motor Nerves by Regenerating Motor Axons  

Microsoft Academic Search

Regeneration of axons into inappropriate distal nerve branches may adversely affect functional recovery after pe- ripheral nerve suture. The degree to which motor axons rein- nervate sensory nerves, and vice versa, has not been de- termined. In these experiments, HRP is used to quantify the sensory and motor neurons that reinnervate sensory and motor branches of the rat femoral nerve

Thomas M. E. Brushart


Genetics Home Reference: Hereditary sensory and autonomic neuropathy type II  


... that primarily affects the sensory nerve cells (sensory neurons), which transmit information about sensations such as pain, ... the sensations of pain, temperature, and touch (sensory neurons). The mutations involved in HSAN2A result in an ...


Infraorbital nerve transection alters serotonin transporter expression in sensory pathways in early postnatal rat development 1 Published on the World Wide Web on 23 October 1998. 1  

Microsoft Academic Search

The serotonin transporter MRNA has been found throughout the trigeminal sensory system late in gestation and during early postnatal development, a period known to be critical for maturation of the sensory circuitry. The purpose of the present study was to determine whether sensory denervation in newborn rat pups would alter either the density or pattern of expression of the 5-HT

Stefan R Hansson; Theresa M Cabrera-Vera; Beth J Hoffman



Compound activity in sensory nerve fibers is related to intensity of sensation evoked by air-puff stimulation of the index finger in man.  


An analysis of a population response recorded from the primary afferents was undertaken to study the neural signs of intensity coding in the peripheral somatosensory system. Short air-puff stimuli were applied to the volar aspect of the tip of the index finger to obtain both neural and psychophysical responses. The detection threshold (So) was first determined and 6 levels of stimulus intensity above threshold (So + 0.25 kg/cm2, So + 1.25 kg/cm2, So + 2.50 kg/cm2, So + 3.75 kg/cm2, So + 5.00 kg/cm2, and So + 6.25 kg/cm2) were adopted for magnitude estimation using the stimulus level of So + 2.50 kg/cm2 as the standard stimulus. The subject was asked to give a numerical estimate of the intensity of a series of stimuli randomly presented. Compound sensory nerve action potentials (SNAPs) were also recorded from surface electrodes over the median nerve at the wrist for the 6 stimulus intensities. Eight SNAP components (4 positive and 4 negative) were recorded within 10 msec following stimulation. A simple power function with an exponent of 0.85 provided an adequate description of the magnitude estimation function, as was verified by the high correlation coefficient (r = 0.89, P less than 0.001). Similarly, stimulus-amplitude functions of individual SNAP components were well represented by straight lines in double logarithmic plots. The function of the late N2-P3 component had the highest power exponent (0.80) and also the highest correlation coefficient (r = 0.59, P less than 0.001). The functions of other SNAP components had considerably lower power exponents with lower correlation coefficients. Thus, a mismatch between neural and psychophysical functions was obvious when individual neural functions were compared with the psychophysical function. Conversely, it was found likely that the total number or time-integral of peaks in the population response was a more pertinent parameter of neural activity and, thus, had a closer correlation with the psychophysical response. PMID:1710966

Hashimoto, I; Gatayama, T; Yoshikawa, K; Sasaki, M; Nomura, M



Inhibition of calcineurin inhibits the desensitization of capsaicin-evoked currents in cultured dorsal root ganglion neurones from adult rats  

Microsoft Academic Search

Capsaicin activates a non-specific cation conductance in mammalian sensory neurones. If capsaicin is applied continuously\\u000a or repeatedly then there is a progressive decline in responsiveness. We have studied the mechanism of this desensitization\\u000a using electro-physiological methods in cultured dorsal root ganglion neurones from adult rats. The rate of desensitization\\u000a of capsaicin-induced responses is partly dependent on the extracellular calcium concentration

R. J. Docherty; J. C. Yeats; S. Bevan; H. W. G. M. Boddeke



Inhibition of calcineurin inhibits the desensitization of capsaicin-evoked currents in cultured dorsal root ganglion neurones from adult rats  

Microsoft Academic Search

Capsaicin activates a non-specific cation conductance in mammalian sensory neurones. If capsaicin is applied continuously\\u000a or repeatedly then there is a progressive decline in responsiveness. We have studied the mechanism of this desensitization\\u000a using electrophysiological methods in cultured dorsal root ganglion neurones from adult rats. The rate of desensitization\\u000a of capsaicin-induced responses is partly dependent on the extracellular calcium concentration

R. J. Docherty; J. C. Yeats; S. Bevan; H. W. G. M. Boddeke



Bioenergetic deficits in peripheral nerve sensory axons during chemotherapy-induced neuropathic pain resulting from peroxynitrite-mediated post-translational nitration of mitochondrial superoxide dismutase.  


Many of the widely used anticancer drugs induce dose-limiting peripheral neuropathies that undermine their therapeutic efficacy. Animal models of chemotherapy-induced painful peripheral neuropathy (CIPN) evoked by a variety of drug classes, including taxanes, vinca alkaloids, platinum-complexes, and proteasome-inhibitors, suggest that the common underlying mechanism in the development of these neuropathies is mitotoxicity in primary nerve sensory axons (PNSAs) arising from reduced mitochondrial bioenergetics [eg adenosine triphosphate (ATP) production deficits due to compromised respiratory complex I and II activity]. The causative mechanisms of this mitotoxicity remain poorly defined. However, peroxynitrite, an important pro-nociceptive agent, has been linked to mitotoxicity in several disease states and may also drive the mitotoxicity associated with CIPN. Our findings reveal that the development of mechano-hypersensitivity induced by paclitaxel, oxaliplatin, and bortezomib was prevented by administration of the peroxynitrite decomposition catalyst Mn(III) 5,10,15,20-tetrakis(N-n-hexylpyridinium-2-yl)porphyrin (MnTE-2-PyP(5+)) without interfering with their anti-tumor effects. Peak CIPN was associated with the nitration and inactivation of superoxide dismutase in the mitochondria, but not in the cytosol, as well as a significant decrease in ATP production within the PNSAs; all of these events were attenuated by MnTE-2-PyP(5+). Our results provide continued support for the role of mitotoxicity in the development of CIPN across chemotherapeutic drug classes, and identify peroxynitrite as a key mediator in these processes, thereby providing the rationale towards development of "peroxynitrite-targeted" therapeutics for CIPN. PMID:23891899

Janes, Kali; Doyle, Timothy; Bryant, Leesa; Esposito, Emanuela; Cuzzocrea, Salvatore; Ryerse, Jan; Bennett, Gary J; Salvemini, Daniela



Relaxation as a Factor in Semantic Desensitization  

ERIC Educational Resources Information Center

|Relaxation and semantic desensitization were used to alleviate the fear of phobic females. Results showed that semantic desensitization, alone or in combination with relaxation, failed to modify the evaluative meanings evoked by the feared object. (SE)|

Bechtel, James E.; McNamara, J. Regis



Synaptic Desensitization of NMDA Receptors by Calcineurin  

Microsoft Academic Search

Desensitization is a phenomenon that is common to many ligand-gated ion channels but has been demonstrated only rarely with physiological stimulation. Numerous studies describe desensitization of the N-methyl-D-aspartate (NMDA) subtype of glutamate receptor by exogenous agonists, but whether synaptic stimulation causes desensitization has been unknown. Synaptic stimulation of NMDA receptors on rat hippocampal neurons resulted in desensitization that was prevented

Gang Tong; Dawn Shepherd; Craig E. Jahr



Purinergic signalling in sensory systems  

Microsoft Academic Search

Extracellular purines play multiple roles in a variety of sensory systems acting as neural signalling and humoral factors via purinoceptors. For example, ATP and adenosine have a neurosignalling role in autonomic sensory–motor reflexes, mechanoreception and chemoreception mediated via vagus nerve afferents, and in nociception. Purinergic neuromodulation of vision via adenosine in the retina is well established and there is mounting

Peter R. Thorne; Gary D. Housley



Peripheral nerve and muscle.  


This review of the past year's literature on neurophysiology of muscles and peripheral nerves emphasizes areas with direct clinical interest. The subject is diversified but will be discussed under the following major headings: nerve conduction studies, electromyography, magnetic motor evoked potentials, quantitative sensory testing, assessment of peripheral pain fibers, and autonomic function assessment. PMID:8293143

Jamal, G A; Mann, C



An artificial nerve fiber for evaluation of nerve cuff electrodes  

Microsoft Academic Search

The different applications of natural sensors for feedback in rehabilitation systems using functional electrical stimulation (FES) require specialised and optimised designs of nerve cuff electrodes for recording of the sensory information. This paper describes a simple artificial nerve fiber for evaluation of nerve cuff electrode designs, cuff recording configurations and noise reduction methods in a controlled environment. The idea is

Lotte N. S. Andreasen; Johannes J. Struijk; Morten Haugland




Microsoft Academic Search

PurposeBotulinum neurotoxin type A (BoNT\\/A) is effective in the treatment of intractable detrusor overactivity (DO). In addition to its known inhibitory effect on presynaptic release of acetylcholine by motor terminals, there is increasing evidence that BoNT\\/A may affect sensory fibers. We investigated a possible effect of BoNT\\/A on human bladder afferent mechanisms by studying the sensory receptors P2X3 and TRPV1




Desensitization of Mouse Nicotinic Acetylcholine Receptor Channels  

PubMed Central

The rate constants of acetylcholine receptor channels (AChR) desensitization and recovery were estimated from the durations and frequencies of clusters of single-channel currents. Diliganded-open AChR desensitize much faster than either unliganded- or diliganded-closed AChR, which indicates that the desensitization rate constant depends on the status of the activation gate rather than the occupancy of the transmitter binding sites. The desensitization rate constant does not change with the nature of the agonist, the membrane potential, the species of permeant cation, channel block by ACh, the subunit composition (? or ?), or several mutations that are near the transmitter binding sites. The results are discussed in terms of cyclic models of AChR activation, desensitization, and recovery. In particular, a mechanism by which activation and desensitization are mediated by two distinct, but interrelated, gates in the ion permeation pathway is proposed.

Auerbach, Anthony; Akk, Gustav



Quantitative pathology of cutaneous nerve terminal degeneration in the human skin  

Microsoft Academic Search

Pathological diagnosis of neuropathy has traditionally depended on ultrastructural examinations of nerve biopsy specimens, particularly for sensory neuropathies affecting unmyelinated and small-myelinated nociceptive nerves. These sensory nerves terminate in the epidermis of the skin, and the pathology of neuropathy usually begins from nerve terminals. We investigated the feasibility of diagnosing small-fiber sensory neuropathy by evaluating cutaneous innervation. Skin biopsy specimens

Hsiung-Fei Chien; To-Jung Tseng; Whei-Min Lin; Chih-Chao Yang; Yang-Chyuan Chang; Rong-Chi Chen; Sung-Tsang Hsieh



Comparative study of the neuronal plasticity along the neuraxis of the vibrissal sensory system of adult rat following unilateral infraorbital nerve damage and subsequent regeneration  

Microsoft Academic Search

The aim of the present study was to examine the physiological consequences of a unilateral infraorbital nerve lesion and\\u000a its regeneration at different levels of the somatosensory neuraxis. In animals whose right infraorbital nerve had been crushed,\\u000a a large unresponsive area was found in the main brainstem trigeminal nucleus (Pr5). Responses evoked by ipsilateral vibrissal\\u000a deflection in the middle of

Zsolt Kis; Tamás Farkas; Katalin Rábl; Edina Kis; Katalin Kóródi; László Simon; Ildikó Marusin; Imre Rojik; József Toldi



cAMP-Dependent Protein Kinase Regulates Desensitization of the Capsaicin Receptor (VR1) by Direct Phosphorylation  

Microsoft Academic Search

The capsaicin receptor, VR1 (also known as TRPV1), is a ligand-gated ion channel expressed on nociceptive sensory neurons that responds to noxious thermal and chemical stimuli. Capsaicin responses in sensory neurons exhibit robust potentiation by cAMP-dependent protein kinase (PKA). In this study, we demonstrate that PKA reduces VR1 desensitization and directly phosphorylates VR1. In vitro phosphorylation, phosphopeptide mapping, and protein

Gautam Bhave; Weiguo Zhu; Haibin Wang; D. J Brasier; Gerry S Oxford; Robert W Gereau IV



Synaptic Potentials of Neurons of the Principal Sensory Trigeminal Nucleus.  

National Technical Information Service (NTIS)

Excitatory postsynaptic potentials and action potentials of neurons of the principal sensory trigeminal nucleus evoked by stimulation of sensory branches of the trigeminal nerves were recorded in cats with intracellular microelectrodes. Neurons of the pri...

Y. P. Limanskii



Synaptic Potentials of Neurons of the Principal Sensory Trigeminal Nucleus.  

National Technical Information Service (NTIS)

Excitatory postsynaptic potentials and action potentials of the neurones of main sensory triple nucleus in response to stimulation of sensory branches of the triple nerves of cat have been recorded intracellularly by means of microelectrodes. The neurones...

Y. P. Limanskii



Impaired molecular regenerative responses in sensory neurones of diabetic rats: gene expression changes in dorsal root ganglia after sciatic nerve crush.  


This study investigated changes in gene expression in lumbar dorsal root ganglia (DRG), contralateral and ipsilateral to a sciatic nerve crush in control and streptozotocin (STZ)-induced diabetic rats. After 10 weeks of diabetes, the left sciatic nerves of all rats were crushed at mid-thigh level, and the rats were maintained for a further 2 weeks. Northern blots, with internal standards, were made from L4 and L5 (pooled) DRG on each side to compare RNA hybrids from ganglia attached to crushed nerves with those attached to intact nerves. The expression of growth-associated proteins, GAP-43 and Talpha1 alpha-tubulin mRNA in DRG, was stimulated (all P < 0.05) by crush injury in control and diabetic rats. Steady-state expression of transcripts for neurofilament (NF) proteins (NF-L, NF-H) and the high-affinity NGF receptor, trkA was decreased by diabetes in the contralateral ganglia to the crush (all P < 0.05). Crush injury further decreased expression of these transcripts in both control and diabetic rats (all P < 0.05). This reduced expression of mRNA coding for both growth-associated proteins, and neurofilament proteins in ganglia of diabetic rats could participate in the reduced competence of the regenerative response to nerve crush. PMID:9392496

Mohiuddin, L; Tomlinson, D R



Hereditary motor and sensory neuropathy--Lom, a novel demyelinating neuropathy associated with deafness in gypsies. Clinical, electrophysiological and nerve biopsy findings  

Microsoft Academic Search

Summary A previously unrecognized neuropathy was identified in Bulgarian gypsies, and was designated hereditary motor and sensory neuropathy-Lom (HMSNL) after the town where the initial cases were found. It was subsequently identified in other gypsy communities. The disorder, which is of autosomal recessive inheritance, was mapped to chromosome 8q24. It begins consistently in the first decade of life with gait

Luba Kalaydjieva; Amelia Nikolova; Ivo Turnev; Julia Petrova; Anna Hristova; Boryana Ishpekova; Iva Petkova; Alexander Shmarov; Stella Stancheva; L. Middleton; Luciano Merlini; A. Trogu; J. R. Muddle; R. H. M. King; P. K. Thomas



Endogenous Opiate System and Systematic Desensitization.  

ERIC Educational Resources Information Center

|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…

Egan, Kelly J.; And Others



Clinical application of sensory protection of denervated muscle  

PubMed Central

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.

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



Genetics Home Reference: Hereditary sensory and autonomic neuropathy type IE  


... HSAN IE is characterized by impaired function of nerve cells called sensory neurons, which transmit information about sensations ... not well understood, the enzyme may help regulate nerve cell (neuron) maturation and specialization (differentiation), the ability of ...


Use of cone-beam computed tomography in the diagnosis of sensory nerve paresthesia secondary to orthodontic tooth movement: a clinical report.  


In this article, we report an incident of transient neuropathy secondary to tooth movement involving the inferior alveolar nerve. This clinical report reflects the need to thoroughly examine potentially high-risk patients for neuropathy using advanced diagnostic tools such as cone-beam computed tomography when diagnosing and planning treatment. PMID:23910211

Chana, Randeep S; Wiltshire, William A; Cholakis, Anastasia; Levine, Gary



Neuronal Nitric Oxide Synthase mRNA Upregulation in Rat Sensory Neurons after Spinal Nerve Ligation: Lack of a Role in Allodynia Development  

Microsoft Academic Search

Pharmacological evidence suggests a functional role for spinal nitric oxide (NO) in the modulation of thermal and\\/or inflamma- tory hyperalgesia. To assess the role of NO in nerve injury- induced tactile allodynia, we examined neuronal NO synthase (nNOS) expression in the spinal cord and dorsal root ganglia (DRG) of rats with tactile allodynia because of either tight ligation of the

Z. David Luo; S. R. Chaplan; B. P. Scott; D. Cizkova; N. A. Calcutt; T. L. Yaksh



Shock desensitizing of solid explosive  

SciTech Connect

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.

Davis, William C [Los Alamos National Laboratory



Nerve conduction and electromyography studies.  


Nerve conduction studies (NCS) and electromyography (EMG), often shortened to 'EMGs', are a useful adjunct to clinical examination of the peripheral nervous system and striated skeletal muscle. NCS provide an efficient and rapid method of quantifying nerve conduction velocity (CV) and the amplitude of both sensory nerve action potentials (SNAPs) and compound motor action potentials (cMAPs). The CV reflects speed of propagation of action potentials, by saltatory conduction, along large myelinated axons in a peripheral nerve. The amplitude of SNAPs is in part determined by the number of axons in a sensory nerve, whilst amplitude of cMAPs reflects integrated function of the motor axons, neuromuscular junction and striated muscle. Repetitive nerve stimulation (RNS) can identify defects of neuromuscular junction (NMJ) transmission, pre- or post-synaptic. Needle EMG examination can detect myopathic changes in muscle and signs of denervation. Combinations of these procedures can establish if motor and/or sensory nerve cell bodies or peripheral nerves are damaged (e.g. motor neuronopathy, sensory ganglionopathy or neuropathy), and also indicate if the primary target is the axon or the myelin sheath (i.e. axonal or demyelinating neuropathies). The distribution of nerve damage can be determined as either generalised, multifocal (mononeuropathy multiplex) or focal. The latter often due to compression at the common entrapment sites (such as the carpal tunnel, Guyon's canal, cubital tunnel, radial groove, fibular head and tarsal tunnel, to name but a few of the reported hundred or so 'entrapment neuropathies'). PMID:22614870

Kane, N M; Oware, A



Sensory and motor neuropathy in a Border Collie.  


A 5-month-old female Border Collie was evaluated because of progressive hind limb ataxia. The predominant clinical findings suggested a sensory neuropathy. Sensory nerve conduction velocity was absent in the tibial, common peroneal, and radial nerves and was decreased in the ulnar nerve; motor nerve conduction velocity was decreased in the tibial, common peroneal, and ulnar nerves. Histologic examination of nerve biopsy specimens revealed considerable nerve fiber depletion; some tissue sections had myelin ovoids, foamy macrophages, and axonal degeneration in remaining fibers. Marked depletion of most myelinated fibers within the peroneal nerve (a mixed sensory and motor nerve) supported the electrodiagnostic findings indicative of sensorimotor neuropathy. Progressive deterioration in motor function occurred over the following 19 months until the dog was euthanatized. A hereditary link was not established, but a littermate was similarly affected. The hereditary characteristic of this disease requires further investigation. PMID:16266014

Harkin, Kenneth R; Cash, Walter C; Shelton, G Diane



Behavioral assessment of facial pain in rats: face grooming patterns after painful and non-painful sensory disturbances in the territory of the rat's infraorbital nerve  

Microsoft Academic Search

Noxious stimulation of the rat's face evokes intense face grooming with face wash strokes almost exclusively directed to the stimulated area (e.g. Clavelou et al., Neurosci. Lett., 14 (1989) 3263–3270). Similar asymmetric face grooming behavior has been observed after transection (Berridge and Fentress, J. Neurosci., 6 (1986) 325–330) and chronic constriction of the infraorbital nerve (Vos et al., J. Neurosci.,

Bart P. Vos; Guy Hans; Hugo Adriaensen



?-Opioid receptor desensitization: homologous or heterologous?  

PubMed Central

There is considerable controversy over whether ?-opioid receptor (MOPr) desensitization is homologous or heterologous and over the mechanisms underlying such desensitization. In different cell types MOPr desensitization has been reported to involve receptor phosphorylation by various kinases, including G-protein-coupled receptor kinases (GRKs), second messenger and other kinases as well as perturbation of the MOPr effector pathway by GRK sequestration of G protein ?? subunits or ion channel modulation. Here we report that in brainstem locus coeruleus (LC) neurons prepared from relatively mature rats (5–8 weeks old) rapid MOPr desensitization induced by the high-efficacy opioid peptides methionine enkephalin and DAMGO was homologous and not heterologous to ?2-adrenoceptors and somatostatin SST2 receptors. Given that these receptors all couple through G proteins to the same set of G-protein inwardly rectifying (GIRK) channels it is unlikely therefore that in mature neurons MOPr desensitization involves G protein ?? subunit sequestration or ion channel modulation. In contrast, in slices from immature animals (less than postnatal day 20), MOPr desensitization was observed to be heterologous and could be downstream of the receptor. Heterologous MOPr desensitization was not dependent on protein kinase C or c-Jun N-terminal kinase activity, but the change from heterologous to homologous desensitization with age was correlated with a decrease in the expression levels of GRK2 in the LC and other brain regions. The observation that the mechanisms underlying MOPr desensitization change with neuronal development is important when extrapolating to the mature brain results obtained from experiments on expression systems, cell lines and immature neuronal preparations.

Llorente, Javier; Lowe, Janet D; Sanderson, Helen S; Tsisanova, Elena; Kelly, Eamonn; Henderson, Graeme; Bailey, Chris P



Mast cell desensitization to IgE fails to induce a parallel adenosine receptor desensitization  

Microsoft Academic Search

Desensitization induced by challenge of mast cells with antigen is specific for IgE-dependent signals. During the secretory process mast cells release adenosine, which can induce a desensitization of adenosine receptors. To determine whether adenosine receptors may de desensitized from a previous antigen challenge, mast cells were sensitized with anti-DNP IgE antibody, challenged with DNP-BSA antigen, returned to culture overnight, resensitized,

D. L. Marquardt; A. Lwin; L. L. Walker



Etodolac activates and desensitizes transient receptor potential ankyrin 1.  


The transient receptor potential ankyrin 1 (TRPA1) channel is well known as a sensor to environmental irritant compounds, cold, and endogenous proalgesic agents. TRPA1 is expressed on sensory neurons and is involved in pain modulation. Etodolac is a cyclooxygenase (COX)-2 inhibitor that belongs to the class of nonsteroidal anti-inflammatory drugs (NSAIDs). A recent study indicates that etodolac inhibits allyl isothiocyanate (AITC)-induced calcium influx in heterologous HEK293 cells and sensory neurons. To examine whether and how etodolac modulates the TRPA1 channels, we applied etodolac to TRPA1-transfected HEK293 cells or rat dorsal root ganglion (DRG) neurons and recorded the currents using the whole-cell patch clamp technique. We found that etodolac at higher doses could activate and then desensitize TRPA1 channels in heterologous expressing HEK293 cells as well as in DRG neurons. The etodolac-induced currents were significantly attenuated in cysteine residues mutated human TRPA1-transfected HEK293 cells. Interestingly, application of etodolac at drug plasma levels in clinical usage did not induce significant TRPA1 currents but reduced the subsequent AITC-induced currents to 25% in HEK293 cells expressing TRPA1. Moreover, no modulatory effect of etodolac on TRPA1 was detected in the cysteine mutant cells. These data indicate a novel mechanism of the anti-inflammatory and analgesic clinical effects of etodolac, which may be involved with its direct activation and the subsequent desensitization of TRPA1 through the covalent modification of cysteine residues. © 2013 Wiley Periodicals, Inc. PMID:24027177

Wang, Shenglan; Dai, Yi; Kogure, Yoko; Yamamoto, Satoshi; Zhang, Wensheng; Noguchi, Koichi



PP2B/calcineurin-mediated desensitization of TRPV1 does not require AKAP150  

PubMed Central

Activation of protein kinases and phosphatases at the plasma membrane often initiates agonist-dependent signalling events. In sensory neurons, AKAP150 (A-kinase-anchoring protein 150) orientates PKA (protein kinase A), PKC (protein kinase C) and the Ca2+/calmodulin-dependent PP2B (protein phosphatase 2B, also known as calcineurin) towards membrane-associated substrates. Recent evidence indicates that AKAP150-anchored PKA and PKC phosphorylate and sensitize the TRPV1 (transient receptor potential subfamily V type 1 channel, also known as the capsaicin receptor). In the present study, we explore the hypothesis that an AKAP150-associated pool of PP2B catalyses the dephosphorylation and desensitization of TRPV1. Biochemical, electrophysiological and cell-based experiments indicate that PP2B associates with AKAP150 and TRPV1 in cultured TG (trigeminal ganglia) neurons. Gene silencing of AKAP150 reduces basal phosphorylation of TRPV1. However, functional studies in neurons isolated from AKAP150?/? mice indicate that the anchoring protein is not required for pharmacological desensitization of TRPV1. Behavioural analysis of AKAP150?/? mice further support this notion, demonstrating that agonist-stimulated desensitization of TRPV1 is sensitive to PP2B inhibition and does not rely on AKAP150. These findings allow us to conclude that pharmacological desensitization of TRPV1 by PP2B may involve additional regulatory components.

Por, Elaine D.; Samelson, Bret K.; Belugin, Sergei; Akopian, Armen N.; Scott, John D.; Jeske, Nathaniel A.



PP2B/calcineurin-mediated desensitization of TRPV1 does not require AKAP150.  


Activation of protein kinases and phosphatases at the plasma membrane often initiates agonist-dependent signalling events. In sensory neurons, AKAP150 (A-kinase-anchoring protein 150) orientates PKA (protein kinase A), PKC (protein kinase C) and the Ca2+/calmodulin-dependent PP2B (protein phosphatase 2B, also known as calcineurin) towards membrane-associated substrates. Recent evidence indicates that AKAP150-anchored PKA and PKC phosphorylate and sensitize the TRPV1 (transient receptor potential subfamily V type 1 channel, also known as the capsaicin receptor). In the present study, we explore the hypothesis that an AKAP150-associated pool of PP2B catalyses the dephosphorylation and desensitization of TRPV1. Biochemical, electrophysiological and cell-based experiments indicate that PP2B associates with AKAP150 and TRPV1 in cultured TG (trigeminal ganglia) neurons. Gene silencing of AKAP150 reduces basal phosphorylation of TRPV1. However, functional studies in neurons isolated from AKAP150-/- mice indicate that the anchoring protein is not required for pharmacological desensitization of TRPV1. Behavioural analysis of AKAP150-/- mice further support this notion, demonstrating that agonist-stimulated desensitization of TRPV1 is sensitive to PP2B inhibition and does not rely on AKAP150. These findings allow us to conclude that pharmacological desensitization of TRPV1 by PP2B may involve additional regulatory components. PMID:20883208

Por, Elaine D; Samelson, Bret K; Belugin, Sergei; Akopian, Armen N; Scott, John D; Jeske, Nathaniel A



Allergen–Induced Sensory Neuroplasticity in Airways  

Microsoft Academic Search

This study investigates the influence of allergic inflammation in airway sensory innervation. We conclude that allergic inflammation in the guinea pig leads to both an increase in excitability, as manifested by an increase in the mechanical sensitivity of the airway nerve endings, and an induction of substance P production in airway sensory neurons. The data are consistent with the hypothesis

Bradley J. Undem; Dawn D. Hunter; Mark Liu; Angela Oakragly; Axel Fischer



Sensory neuropathy in two Border collie puppies.  


A peripheral sensory neuropathy was diagnosed in two Border collie puppies. Neurological, electrophysiological and histopathological examinations suggested a purely sensory neuropathy with mainly distal involvement. Urinary incontinence was observed in one of the puppies and histological examination of the vagus nerve revealed degenerative changes. An inherited disorder was suspected. PMID:15971901

Vermeersch, K; Van Ham, L; Braund, K G; Bhatti, S; Tshamala, M; Chiers, K; Schrauwen, E



Percutaneous peripheral nerve stimulation.  


Since its inception in the 1970s, peripheral neuromodulation has become an increasingly common procedure to treat chronic neuropathic disorders. Historically, peripheral nerve stimulation (PNS) originated with the placement of large surface cuff electrodes, which was refined by the introduction of functional nerve mapping with circumferential electrical stimulation. This substantially improved the targeting of sensory fascicles. Surgical placement of spinal cord stimulation (SCS) 'button type' paddle electrodes was replaced when the introduction of percutaneous cylindrical SCS electrodes expanded the spectrum of PNS applications and improved the ability to target afferent sensory fibers as well as reducing the complication rate. To further refine functional mapping for the placement of these percutaneous electrodes, radiofrequency needle probes have more recently been employed to elicit paresthesias in awake patients to map the pain generators and guide treatment. In this chapter, we provide a description of the development and basic mechanisms of peripheral nerve stimulation, as well as a more detailed description of the two most commonly employed forms of peripheral nerve stimulation: occipital nerve stimulation for occipital neuralgia, and subcutaneous peripheral nerve field stimulation to stimulate free nerve endings within the subcutaneous tissue when the pain is limited to a small, well-localized area. The closely related ideas of internal and external targeted subcutaneous stimulation are also discussed. PMID:21422775

Aló, Kenneth M; Abramova, Marina V; Richter, Erich O



Modeling study of peripheral nerve recording selectivity  

Microsoft Academic Search

Recording of sensory information from afferent fibers can be used as feedback for the closed-loop control of neural prostheses. Clinical applications suggest that recording selectively from various nerve fascicles is important. Current nerve cuff electrodes are generally circular in shape and use a tripolar recording configuration. Preliminary experiments suggest that slowly changing the shape of the nerve to a flatter

Javier Perez-Orive; D. M. Durund



Cilia in Nematode Sensory Organs  

Microsoft Academic Search

Electron microscopic studies revealed the presence of true cilia in nerve processes connected with sensory organs of a nematode. These structures are important in evaluating the relation between nematodes and the other aschelminths, from which they were separated partially on the basis of the supposed total absence of cilia.

D. R. Roggen; D. J. Raski; N. O. Jones



Continuous Femoral Nerve Blocks: Varying Local Anesthetic Delivery Method (Bolus versus Basal) to Minimize Quadriceps Motor Block while Maintaining Sensory Block  

PubMed Central

Background Whether the method of local anesthetic administration for continuous femoral nerve blocks —basal infusion versus repeated hourly bolus doses —influences block effects remains unknown. Methods Bilateral femoral perineural catheters were inserted in volunteers (n = 11). Ropivacaine 0.1% was administered through both catheters concurrently: a 6-h continuous 5 ml/h basal infusion on one side and 6 hourly bolus doses on the contralateral side. The primary endpoint was the maximum voluntary isometric contraction (MVIC) of the quadriceps femoris muscle at Hour 6. Secondary end points included quadriceps MVIC at other time points, hip adductor MVIC, and cutaneous sensation 2 cm medial to the distal quadriceps tendon in the 22 h following local anesthetic administration initiation. Results Quadriceps MVIC for limbs receiving 0.1% ropivacaine as a basal infusion declined by a mean (SD) of 84% (19) compared with 83% (24) for limbs receiving 0.1% ropivacaine as repeated bolus doses between baseline and Hour 6 (paired t test P = 0.91). Intrasubject comparisons (left vs. right) reflected a lack of difference as well: the mean basal-bolus difference in quadriceps MVIC at Hour 6 was ?1.1% (95% CI ?22.0 to 19.8%). The similarity did not reach our a priori threshold for concluding equivalence, which was the 95% CI falling within ± 20%. There were similar minimal differences in the secondary endpoints during local anesthetic administration. Conclusions This study did not find evidence to support the hypothesis that varying the method of local anesthetic administration —basal infusion versus repeated bolus doses —influences continuous femoral nerve block effects to a clinically significant degree.

Charous, Matthew T.; Madison, Sarah J.; Suresh, J.; Sandhu, NavParkash S.; Loland, Vanessa J.; Mariano, Edward R.; Donohue, Michael C.; Dutton, Pascual H.; Ferguson, Eliza J.; Ilfeld, Brian M.



[P2x3-receptor desensitization as an alternative mechanism of analgesia].  


One of the most important current medical problems is the synthesis of substances that could suppress pathological pain. It has not been yet invented any method for chronic pain inhibition. Chronic pain is largely mediated by the activation of purinergic P2X3- and P2X2/3-receptors. They are expressed in nociceptive sensory neurons and are the prospective targets for analgesic drugs. There are several potential strategies to prevent P2X3 receptor activation. Recent studies have shown that P2X3-receptor antagonists and genetic deletion may have analgesic effects in inflammatory and neuropathic models. P2X3-receptors have fast and persistent desensitization. By influencing this property it could serve to reduce the ATP-mediated sensation of chronic pain. Therefore, in this review we outline and analyze the effectiveness and prospects of pharmacological agents acting through desensitization of P2X3-receptor versus its competitive antagonists. PMID:23828978

Petrenko, N S; Kryshtal', O O



Convergence of cervical and trigeminal sensory afferents  

Microsoft Academic Search

Cranial nociceptive perception shows a distinct topographic distribution, with the trigeminal nerve receiving sensory information\\u000a from the anterior portions of the head, the greater occipital nerve, and branches of the upper cervical roots in the posterior\\u000a regions. However, this distribution is not respected during headache attacks, even if the etiology of the headache is specific\\u000a for only one nerve. Nociceptive

Elcio J. Piovesan; Pedro A. Kowacs; Michael L. Oshinsky



Influence of human skin injury on regeneration of sensory neurons  

Microsoft Academic Search

The regeneration of sensory nerve fibres is regulated by trophic factors released from their target tissue, particularly the basal epidermis, and matrix molecules. Means to modulate this response may be useful for the treatment of neuromas and painful hypertrophic scars and of sensory deficits in skin grafts and flaps. We have developed an in vitro model of sensory neuron regeneration

O. Taherzadeh; W. R. Otto; U. Anand; J. Nanchahal; P. Anand



Preshock desensitization of PBX explosives  

SciTech Connect

Preshocking delays initiation of PBX-9404 and PBX-9501, relative to unshocked material. In PBX-9404 preshock experiments, a first shock of 2.3 GPa was followed 0.65 {mu}s later by a second shock of 5.6 GPa. In PBX-9501, a preshock of 2.8 GPa and 0.32 us duration was followed by an initiating shock of 6.0 GPA. Both PBX explosives show clear desensitization while the preshock persists. In PBX-9404, initiation of detonation occurs nearly as anticipated for the material, after coalescence of the preshock and main shock into a single wave. Multiple embedded magnetic gauges were used to measure the shock histories. Our data indicates a slightly longer run to detonation than expected, even though a single wave is initiating the material. A slight stress reduction at coalescence, as required by the shock dynamics, may be responsible for the overrun. A reactive waste is clearly evident while the preshock persists. The long run to detonation indicates that this reactive wave is not driving the initiation. A set of four preshock experiments were preformed on PBX-9502, which is unreactive at these pressures, to investigate the shock dynamics of the two waves in the HE.

Mulford, R.N.; Sheffield, S.A.; Alcon, R.R.



Repair of a median nerve transection injury using multiple nerve transfers, with long-term functional recovery.  


Complete loss of median nerve motor function is a rare but devastating injury. Loss of median motor hand function and upper-extremity pronation can significantly impact a patient's ability to perform many activities of daily living independently. The authors report the long-term follow-up in a case of median nerve motor fiber transection that occurred during an arthroscopic elbow procedure, which was then treated with multiple nerve transfers. Motor reconstruction used the nerves to the supinator and extensor carpi radialis brevis to transfer to the anterior interosseous nerve and pronator. Sensory sensation was restored using the lateral antebrachial cutaneous (LABC) nerve to transfer to a portion of the sensory component of the median nerve, and a second cable of LABC nerve as a direct median nerve sensory graft. The patient ultimately recovered near normal motor function of the median nerve, but had persistent pain symptoms 4 years postinjury. PMID:22978538

Murphy, Rory K J; Ray, Wilson Z; Mackinnon, Susan E



Sensory syndromes.  


Somatosensory deficit syndromes represent a common impairment following stroke and have a prevalence rate of around 80% in stroke survivors. These deficits restrict the ability of survivors to explore and manipulate their environment and are generally associated with a negative impact on quality of life and personal safety. Sensory impairments affect different sensory modalities in diverse locations at varying degrees, ranging from complete hemianesthesia of multiple modalities to dissociated impairment of somatosensory submodalities within a particular region of the body. Sensory impairments induce typical syndromal patterns which can be differentiated by means of a careful neurological examination, allowing the investigator to deduce location and size of the underlying stroke. In particular, a stroke located in the brainstem, thalamus, and the corticoparietal cortex result in well-differentiable sensory syndromes. Sensory function following stroke can be regained during rehabilitation even without specific sensory training. However, there is emerging evidence that specialized sensory interventions can result in improvement of somatosensory and motor function. Herein, we summarize the clinical presentations, examination, differential diagnoses, and therapy of sensory syndromes in stroke. PMID:22377851

Klingner, Carsten M; Witte, Otto W; Günther, Albrecht



Decoupling control of a multivariable system with a desensitizer  

SciTech Connect

Decoupling control of a multivariable system with a desensitizer has been proposed. Interactions between control loops were decoupled by means of a desensitizer and a two-way decoupler. The objective of the desensitizer was to reduce the decoupler sensitivity while the two-way decoupler was for actually decoupling control loops. The proposed control structure was verified on models of a highly interacting system and a distillation column. The control system with desensitizer significantly enhanced the robustness of the decoupling control system.

Wenteng Wu; Jingwei Ko; Hsingwo Lee (National Tsing Hua Univ., Hsinchu (Taiwan, Province of China). Dept. of Chemical Engineering)



Identification of target areas for deep brain stimulation in human basal ganglia substructures based on median nerve sensory evoked potential criteria  

PubMed Central

Objective: In the interventional treatment of movement disorders, the thalamic ventral intermediate nucleus (VIM) and the subthalamic nucleus (STN) are the most relevant electrode targets for deep brain stimulation (DBS). This study tested the value of somatosensory evoked potentials (SEP) for the functional identification of VIM and STN. Methods: Median nerve SEP were recorded from the final stimulation electrodes targeted at STN and VIM. Throughout the stereotactic procedure SEP were recorded during short electrode stops above STN/VIM and within the presumed target areas. After digital filtering, high and low frequency SEP components were analysed separately to parameterise both the 1000 Hz SEP burst and low frequency (<100 Hz) components. Results: SEP recorded in the VIM target region could unequivocally be distinguished from SEP recorded in STN. The 1000 Hz burst signal was significantly larger in VIM than in STN without any overlap of amplitude values. In the low frequency band, a primary high amplitude negativity was obtained in VIM, contrasting with a low amplitude positivity in STN. SEP waveshapes in recordings above target positions resembled SEP obtained in STN. When entering VIM, a sharp amplitude increase was observed over a few millimetres only. Conclusions: Based on SEP criteria, the VIM target but not the STN region can be identified by typical SEP configuration changes, when penetrating the target zone. The approach is independent of the patient's cooperation and vigilance and therefore feasible in general anaesthesia. It provides an easy, reliable, and robust tool for the final assessment of electrode positions at the last instance during electrode implantation when eventual electrode revisions can easily be performed.

Klostermann, F; Vesper, J; Curio, G



Desensitization Protocol Increases Survival in Kidney Recipients  


... Hopkins University School of Medicine—led by Robert A. Montgomery, M.D., and supported in part by the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)—has developed a protocol that desensitizes a potential kidney recipient to ...


Sensory systems.  


Research on the senses spans the enormous range from analysis of individual molecules involved in sensory transduction to the attempted elucidation of conscious sensation. Because the variety of conceptual and experimental approaches varies so broadly across the field, it is impossible to delineate a single direction for future research. Two trends are nonetheless apparent. At the reductionistic end of the spectrum, in the analysis of sensory transduction, studies on all the senses will increasingly be driven by the techniques of molecular biology. The advent of techniques for producing cDNA libraries from small ensembles of receptor cells, or even from individual cells, will permit the recognition of new constituents of receptor cells and of factors involved in their specification, differentiation, and maintenance. In the integrative realm of sensory neurobiology, future studies will increasingly rely on optical techniques for the study of activity patterns on the surfaces of sensory areas of the cerebral cortex and on noninvasive functional imaging for the investigation of neural responses in human subjects. These techniques will continue to strengthen our understanding of the relation between neuronal activity and conscious sensory experience. PMID:9751666

Hudspeth, A J; Tanaka, K



Axonal degeneration within the tympanal nerve of Schistocerca gregaria  

Microsoft Academic Search

This study describes time course and ultrastructural changes during axonal degeneration of different neurones within the tympanal nerve of the locust Schistocerca gregaria. The tympanal nerve innervates the tergit and pleurit of the first abdominal segment and contains the axons of both sensory and motor neurones. The majority of axons (approx. 97%) belong to several types of sensory neurones: mechano-

Kirsten Jacobs; Reinhard Lakes-Harlan



Effects of peripheral nerve lesions during pregnancy on parturition in rats  

Microsoft Academic Search

Bilateral section of either the sensory or motor branch of the pelvic nerve or pudendal nerve was performed in rats on days 8–10 of pregnancy, and the effects on delivery were observed. Bilateral resection of the sensory branch of the pelvic nerve reduced the number of live pups per litter, and increased the number of stillbirths and the number of

Hubert W. Burden; Gary T. Price; Randall H. Renegar; Charles A. Hodson



Pharmacological enhancement of peripheral nerve regeneration in the rat by systemic acetyl- L-carnitine treatment  

Microsoft Academic Search

Peripheral nerve trauma remains a major cause of morbidity, largely due to the death of ?40% of innervating sensory neurons, and to slow regeneration after repair. Acetyl-L-carnitine (ALCAR) is a physiological peptide that virtually eliminates sensory neuronal death, and may improve regeneration after primary nerve repair. This study determines the effect of ALCAR upon regeneration after secondary nerve repair, thereby

Andrew McKay Hart; Mikael Wiberg; Giorgio Terenghi



Effects of scaphognathite nerve stimulation on the acutely deafferented crab ventilatory central pattern generator  

Microsoft Academic Search

1.Sensory axons from crab (Carcinus maenas) scaphognathites enter the thoracic ganglion primarily via the LNb branch of the levator nerve. The LNa branch of the levator nerve and the depressor nerve each contain relatively few sensory axons.2.Acutely deafferented ventilatory central pattern generators show a free running burst rate which is lower than that observed in intact crabs. Electrical stimulation of

J. L. Wilkens; R. A. DiCaprio



An investigation of potential desensitizing agents in the dentine disc model: a scanning electron microscopy study.  


Cervical dentine sensitivity (CDS) may be defined as pain arising from exposed dentine. The prefix cervical indicates the location of the sensitivity and/or its subsequent treatment. Currently the most accepted mechanism of intradental nerve activation associated with dentine sensitivity appears to be hydrodynamic in nature. The concept of tubule occlusion as a method of dentine desensitization is a logical conclusion of the hydrodynamic theory. The authors employed the dentine disc model, qualitative scanning electron microscopy (SEM) and X-ray microanalysis to investigate whether selected desensitizing agents occlude dentinal tubule orifices. Strict control procedures have been used together with various methods of application to apply these agents to human dentine discs. SEM was used to examine the degree of deposit left by the various agents on disc surfaces and X-ray microanalysis was employed to characterize the elemental composition of the deposit. Analysis of selected agents, both prior to and after application on dentine discs was performed for comparative purposes. The degree of retention of the surface deposit upon rotation with saliva supernatant for 6 h was also studied. The results of this study indicated that ferric oxalate, the active ingredient of Sensodyne Sealant, which produced initial crystal-like structures, occluding almost all the tubule orifices was superior to potassium oxalate (Butler Protect). Of the over-the-counter (OTC) desensitizing products tested, both silica- and calcium-based abrasive components were observed both on the surface and within the tubules, indicating a certain degree of therapeutic potential for these two components. These findings suggest that certain desensitizing agents have tubule occluding properties as observed in this in vitro system which, in turn, may indicate a therapeutic potential in vivo. PMID:9131474

Ling, T Y; Gillam, D G; Barber, P M; Mordan, N J; Critchell, J



Sensory tract abnormality in the chick model of spina bifida.  


Spina bifida aperta (SBA) is an open neural tube defect that occurs during the embryonic period. We created SBA chicks by incising the roof plate of the neural tube in the embryo. The area of the dorsal funiculus was smaller in the SBA chicks than in the normal controls. Additionally, the SBA group had fewer nerve fibres in the dorsal funiculus than the normal controls. The pathway of the ascending sensory nerves was revealed by tracing the degenerated nerve fibres using osmification. We cut the sciatic nerve (L5) of the control and SBA chicks at the central end of the dorsal root ganglion 1 day after hatching and fixed the tissue 3 days later. Degenerated sensory nerve fibres were observed in the ipsilateral dorsal funiculus in the control chicks. In contrast, degenerated sensory nerve fibres were observed in the ipsilateral and contralateral dorsal, ventral and lateral funiculi of the spinal cord in the SBA chicks. Consequently, fewer sensory nerve fibres ascended to the thoracic dorsal funiculus in the SBA chicks than in the normal controls. This is the first report of abnormal changes in the ascending sensory nerve fibres in SBA. PMID:21658418

Tsujimura, Ryusuke; Mominoki, Katsumi; Kinutani, Masae; Shimokawa, Tetsuya; Doihara, Takuya; Nabeka, Hiroaki; Wakisaka, Hiroyuki; Kobayashi, Naoto; Matsuda, Seiji



Using humor in systematic desensitization to reduce fear.  


Effectiveness of systematic desensitization for fear reduction, using humorous hierarchy scenes without relaxation, was tested. Participants were 40 students highly fearful of spiders. Using a 24-item behavioral approach test with an American tarantula, participants were matched on fear level and randomly assigned to 1 of 3 treatment groups: (a) systematic desensitization, (b) humor desensitization, and (c) untreated controls. Each participant was seen for 6 sessions, including pretest and posttest. Analyses of covariance of posttest scores revealed that the 2 treatment groups showed greater reduction in fear than the controls on 3 measures but did not differ from each other. Therefore, humor in systematic desensitization reduced fear as effectively as more traditional desensitization. This finding may have therapeutic applications; however, it may also be applicable in advertising to desensitize fear of a dangerous product, such as cigarettes. PMID:11506052

Ventis, W L; Higbee, G; Murdock, S A



Sodium channels and nociceptive nerve endings  

Microsoft Academic Search

Both C and A? nociceptive neurones express multiple subtypes of Na+ channel. In particular, TTX-resistant Na+ channels appear to play an important role in determining the behaviour of these neurones. Present evidence suggests that initiation of nerve impulses in the sensory nerve terminals of nociceptors is dependent on the activation of TTX-resistant channels. Furthermore, the voltage dependence and kinetics of

James A. Brock



Microsoft Academic Search





Desensitization of parathyroid hormone receptors on cultured bone cells  

SciTech Connect

Administration of excessive amounts of parathyroid hormone (PTH) in the treatment of osteoporosis can reverse the beneficial effects of a low-dose, intermittent regime. To investigate the direct actions and the possible cellular mechanisms of PTH in inducing desensitization of PTH receptors, we studied the effects of desensitization on rat osteoblastic UMR-106 cells. When the osteoblasts were preincubated with bPTH-(1-34), complete refractoriness to a subsequent challenge with the hormone developed within 1 h and at hormone concentrations as low as 5 nM. When osteoblasts thus desensitized were incubated in hormone-free medium, recovery of the cAMP responses began within 2 h and reached maximum after 16 h. Cycloheximide did not affect the process of desensitization. (Nle8,Nle18,Tyr34)bPTH-(3-34)amide significantly impaired the desensitization process by PTH-(1-34) but did not have stimulatory effect on cAMP responses. No significant heterologous desensitization was obvious after preincubation with isoprenaline (50 microM), prostaglandin E1 (50 microM), or prostaglandin E2 (50 microM) for 2 h. Binding experiments with (125I)PLP-(1-36)amide after desensitization revealed that there was an approximate twofold decrease in receptor affinities as analyzed by Scatchard analysis, showing that the decrease in affinity was prominent in the process of desensitization. When the cells were treated with monensin during desensitization, PTH challenge after desensitization produced significantly lower cyclic AMP responses. Recovery after desensitization occurred over a period of 16 h. Inclusion of monensin, but not cycloheximide, impaired the recovery. The results show that homologous desensitization of rat osteoblasts to PTH is brought about by the occupancy of receptors by PTH-(1-34) but not by cAMP generation itself.

Pun, K.K.; Ho, P.W.; Nissenson, R.A.; Arnaud, C.D. (Univ. of Hong Kong (Hong Kong))



Peripheral nerve involvement in Batten-Spielmeyer-Vogt's disease.  

PubMed Central

Electromyography and sensory and motor nerve conduction were studied in 23 patients with Batten-Spielmeyer-Vogt's disease ("juvenile amaurotic idiocy", cerebral ceroidlipofuscinosis). A slight to moderate slowing of the sensory conduction velocity was found in the median as well as in the sural nerve, more pronounced in the distal than in the proximal segments. The findings are interpreted as evidence of impaired transmission of the peripheral nerves in Batten-Spielmeyer-Vogt's disease. Images

Lyon, B B



Desensitization therapy in a patient with furosemide allergy.  


Allergy to furosemide is a rare phenomenon. Desensitization to this sulfa-containing drug has not been frequently performed. We describe a patient with severe congestive heart failure and type I allergy to furosemide. Because of the severity of her condition, we decided to use a rapid intravenous desensitization protocol. Following the desensitization, the patient was treated with intravenous and oral furosemide with a dramatic improvement in her clinical state. We suggest that rapid desensitization may be a safe and effective way of introducing furosemide to allergic patients for whom loop diuretics are urgently indicated. PMID:17223047

Shteinberg, Michal; Karkabi, Basheer; Cohen, Shai



Desensitization of insulin secretion by depolarizing insulin secretagogues.  


Prolonged stimulation of insulin secretion by depolarization and Ca2+ influx regularly leads to a reversible state of decreased secretory responsiveness to nutrient and nonnutrient stimuli. This state is termed "desensitization." The onset of desensitization may occur within 1 h of exposure to depolarizing stimuli. Desensitization by exposure to sulfonylureas, imidazolines, or quinine produces a marked cross-desensitization against other ATP-sensitive K+ channel (KATP channel)-blocking secretagogues. However, desensitized beta-cells do not necessarily show changes in KATP channel activity or Ca2+ handling. Care has to be taken to distinguish desensitization-induced changes in signaling from effects due to the persisting presence of secretagogues. The desensitization by depolarizing secretagogues is mostly accompanied by a reduced content of immunoreactive insulin and a marked reduction of secretory granules in the beta-cells. In vitro recovery from a desensitization by the imidazoline efaroxan was nearly complete after 4 h. At this time point the depletion of the granule content was partially reversed. Apparently, recovery from desensitization affects the whole lifespan of a granule from biogenesis to exocytosis. There is, however, no direct relation between the beta-cell granule content and the secretory responsiveness. Even though a prolonged exposure of isolated islets to depolarizing secretagogues is often associated with the occurrence of ultrastructural damage to beta-cells, we could not find a cogent link between depolarization and Ca2+ influx and apoptotic or necrotic beta-cell death. PMID:15561902

Rustenbeck, Ingo; Wienbergen, Antje; Bleck, Claudia; Jörns, Anne



Histrionicotoxin enhances agonist-induced desensitization of acetylcholine receptor.  


Dihydroisohistrionicotoxin inhibits acetylcholine receptor-dependent 22Na+ uptake of cultured chick muscle cells with a KI of 0.2 micrometer. The inhibition is noncompetitive with respect to agonists. The toxin enhances desensitization of the receptor by agonists which is accompanied by a 10-fold increase in receptor affinity for agonists. Dihydroisohistrionicotoxin increases the affinity of the desensitized form of the receptor for agonists but not antagonists. The results suggest that dihydroisohistrionicotoxin inhibits the acetylcholine receptor by causing an increase in the affinity of the desensitized form of the receptor for agonists and thereby stabilizing the desensitized state. PMID:272000

Burgermeister, W; Catterall, W A; Witkop, B



Desensitization and recovery at the frog neuromuscular junction  

PubMed Central

The time course of carbachol-induced desensitization onset and recovery of sensitivity after desenitization have been compared at the frog neuromuscular junction. The activation-desensitization sequence was determined from input conductance measurements using potassium- depolarized muscle preparations. Both desensitization onset and recovery from desensitization could be adequately described by single time constant expressions, with tauonset being considerably shorter than taurecovery. In nine experiments, tauonset was 13+/-1.3 s and taurecovery was 424+/-51 s with 1 mM carbachol. Elevating the external calcium or carbachol concentration accelerated desensitization onset without changing the recovery of sensitivity after equilibrium desensitization. Desensitization onset was accelerated by a prior activation-desensitization sequence to an extent determined by the recovery interval that followed the initial carbachol application. The time course of return of tauonset was closely parallel to, but slower than the time course of recovery of sensitivity. These results are consistent with a cyclic model in which intracellular calcium is a factor controlling the rate of development of desensitization.



Hyperalgesic actions of cytokines on peripheral nerves  

Microsoft Academic Search

\\u000a The relationship between nerve injury and pain is pervasive in medicine, being both a simple, common experience and an important\\u000a diagnostic tool. Acute trauma to a nerve is almost always painful and has been experienced by many people in association with\\u000a sports and workplace activities. In these cases, injuries occur usually because of nerve stretching or compression, damaging\\u000a sensory axons

Robert R. Myers; Rochelle Wagner; Linda S. Sorkin


Nerve afflictions of maxillofacial region: a report of two cases.  


Neurological disorders and conditions affecting the maxillofacial region result in disabilities that affect an individual's functioning. Sensory or motor disturbances of the nerves may be caused by trauma, infections, pressure effect or infiltration by tumours or other health conditions. Two rare cases of nerve afflictions are described here with their typical clinical features. The first case had an involvement of maxillary, mandibular and ophthalmic divisions of the trigeminal nerve (sensory) due to herpes zoster infection in a very young patient and the second case had a unilateral isolated hypoglossal nerve palsy (motor) secondary to infiltration of the nerve by carcinoma of pyriform fossa. PMID:24145506

Thada, Smitha Rani; Gadda, Rohit; Pai, Keerthilatha



Sensory feedback in upper limb prosthetics.  


One of the challenges facing prosthetic designers and engineers is to restore the missing sensory function inherit to hand amputation. Several different techniques can be employed to provide amputees with sensory feedback: sensory substitution methods where the recorded stimulus is not only transferred to the amputee, but also translated to a different modality (modality-matched feedback), which transfers the stimulus without translation and direct neural stimulation, which interacts directly with peripheral afferent nerves. This paper presents an overview of the principal works and devices employed to provide upper limb amputees with sensory feedback. The focus is on sensory substitution and modality matched feedback; the principal features, advantages and disadvantages of the different methods are presented. PMID:23278223

Antfolk, Christian; D'Alonzo, Marco; Rosén, Birgitta; Lundborg, Göran; Sebelius, Fredrik; Cipriani, Christian



N-Acetylcysteine alters apoptotic gene expression in axotomised primary sensory afferent subpopulations  

Microsoft Academic Search

Novel approaches are required in peripheral nerve injury management because current surgical techniques, which do not address axotomy-induced neuronal death, lead to deficient sensory recovery. Sensory neuronal death has functional preference with cutaneous neurons dying in great numbers whilst muscle afferents survive axotomy. This offers the potential of comparing similar cell types that suffer distinct fates upon nerve injury.Here, a

Adam J. Reid; Susan G. Shawcross; Alex E. Hamilton; Mikael Wiberg; Giorgio Terenghi



Insect sensory systems inspired computing and communications  

Microsoft Academic Search

Insects are the most successful group of living things in terms of the number of species, the biomass and their distribution. Entomological research has revealed that the insect sensory systems are crucial for their success. Compared to human brains, the insect central nerve systems are extremely primitive and simple, both structurally and functionally, and are of minimal learning ability. Faced

Axel W. Krings



Galvanic Skin Response and Reported Anxiety During Systematic Desensitization  

ERIC Educational Resources Information Center

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)

Hyman, Edward T.; Gale, Elliot N.



Human acetylcholine receptors desensitize much faster than rat acetylcholine receptors.  


The process of acetylcholine receptor (AChR) desensitization in the presence of transmitter was evaluated for human myoballs and medullo-blastoma cells. The cell under investigation was placed in one of two parallel streams of solution ejected from a double-barrelled pipette. Ultrafast (less than 50 ms) application of acetylcholine (ACh) in a specific concentration was accomplished by a shift of the cell into the other stream. ACh-induced current was measured in the whole-cell mode of patch clamping. Parameters for AChR desensitization were almost identical for the two types of human cells. Desensitization could be described by two time constants. With an ACh concentration of 3 microM, the fast time constant, tau f, was about 0.4 s and the slow time constant, tau s, was about 3.6 s. When the ACh concentration was raised to 10 microM, desensitization became faster. We also measured desensitization of the AChRs in rat myoballs and compared the values to our results from human cells. With 3 microM ACh, tau f in rat myoballs was 2.3 s and tau s was 12.7 s. Thus, rat AChRs desensitize more slowly than human AChRs. However, desensitization times for rat AChRs obtained in our experiments are much faster than published values. Therefore, ultrafast solution change would seem to be requisite for correct assessment of the desensitization process. PMID:2812518

Siara, J; Ruppersberg, J P; Rüdel, R



Desensitization and recovery of phototropic responsiveness in Arabidopsis thaliana  

SciTech Connect

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 densensitization 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 [mu]mol m[sup [minus]2] s[sup [minus]1]. At equal fluences, blue light caused more desensitization when given at a fluence rate of 1.0 [mu]mol m[sup [minus]2] s[sup [minus]1] than at 0.3 [mu]mol m[sup [minus]2] s[sup [minus]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. 11 refs., 6 figs.

Janoudi, A.K.; Poff, K.L. (Michigan State Univ., East Lansing (United States))



EMG Biofeedback Training Versus Systematic Desensitization for Test Anxiety Reduction  

ERIC Educational Resources Information Center

|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…

Romano, John L.; Cabianca, William A.



Evaluation of Antibacterial Effectiveness of Desensitizers against Oral Bacteria  

PubMed Central

Objectives Desensitizers contribute to better clinical results by reducing the rate of cervical dentin sensitivity. However, information on their antibacterial effect is limited. This study examined the antibacterial activities of a triclosan containing (Seal & Protect), a benzalconium containing desensitizer (Micro Prime), a fluoride containing prophilaxy paste (Sultan Desensitizer), two fluoride containing varnishes (Cavity Shealth and Ultra EZ), and a dentin bonding primer (All Bond). Methods The test materials were inserted in the wells of Muller Hinton agar plates inoculated with Streptococcus mutans, Streptococcus salivarious, Staphylococcus aureus, Streptococcus faecalis and Pseudomonas aeruginosa. The diameters of the inhibition zones produced around the materials were measured after 24 h of incubation. The results were analyzed by the Kruskal Wallis one way ANOVA and the Mann-Whitney tests at a significance level of P<.05. Results Micro Prime Desensitizer containing benzalkonium chloride had the highest antibacterial effectiveness compared to other desensitizers used in this study. In addition, triclosan containing Seal & Protect and acidic components containing All Bond showed very high antibacterial efficacy. On the other hand, fluoride within both varnishes had little antibacterial effectiveness. However a fluoride component in a paste (Sultan Desensitizer) showed very high bactericidal effect. Conclusions All desensitizers except fluoride varnishes showed various degrees of antibacterial effect against the bacteria tested in this study. If antibacterial effect is also required from the desensitizers’ clinicians should avoid use of varnishes.

Duran, Ismet; Sengun, Abdulkadir; Hadimli, Hasan Huseyin; Ulker, Mustafa



Effects of Modeling and Desensitation in Reducing Dentist Phobia  

ERIC Educational Resources Information Center

Many persons avoid dentists and dental work. The present study explored the effects of systematic desensitization and social-modeling treatments with placebo and assessment control groups. Modeling was more effective than desensitization as shown by the number of subjects who went to a dentist. (Author)

Shaw, David W.; Thoresen, Carl E.



Specificity of Glomerular Targeting by Olfactory Sensory Axons  

Microsoft Academic Search

Axons from olfactory sensory neurons (OSNs) expressing a specific odorant receptor (OR) project to specific subsets of glomeruli in the olfactory bulb (for review, see Mombaerts, 1999, 2001). The aim of this study was to examine the trajec- tories that subsets of axons from OSNs expressing the same OR follow within the olfactory nerve and olfactory nerve layer (ONL) of

Helen B. Treloar; Paul Feinstein; Peter Mombaerts; Charles A. Greer



Selective neutrophil desensitization to chemotactic factors  

PubMed Central

In the presence of extracellular calcium and magnesium, a series of chemotactic oligopeptides and C5a caused aggregation of human polymorphonuclear neutrophils (PMNs). This cellular response developed rapidly and began to reverse 2 min after exposure to the chemotactin. In the absence of the bivalent cations, none of the chemotactins stimulated the aggregation response. If cells were first exposed to a chemotactin and then treated with calcium and magnesium, aggregation was detected only after addition of the cations, and the magnitude of the response fell sharply as the interval between the addition of chemotactin and addition of cations was lengthened: when this interval exceeded 2 min, aggregation was barely detectable. This loss of reactivity persisted even when cells were re-exposed to fresh chemotactic factor and washed between the first and second exposures. In all instances, however, loss of cellular reactivity was highly selective: cells preincubated with any chemotactic oligopeptide were hyporesponsive to subsequent stimulation with an oligopeptide but remained fully responsive to C5a; cells preincubated with C5A were hyporesponsive to C5a but retained their responsitivity to the oligopeptides. Because this selectivity parallels the known specificities of these chemotactic factors for their receptors in or on the neutrophil, desensitization may reflect functional loss of receptors after stimulation. Alternatively, this selectivity may indicate that morphologically identical neutrophils contain subpopulations of cells with varying reactivities to receptor-bound chemotactic factors. In either event, desensitization may be useful in functionally defining chemotactic factors and their respective receptors. The rapidity of development of desensitization suggests that it may operate to limit or moderate various in vitro and in vivo neutrophil responses to chemotactic factors.



Desensitization of diliganded mouse muscle nicotinic acetylcholine receptor channels  

PubMed Central

Nicotinic ACh receptor channels (AChRs) exposed to high concentrations of ACh adopt ‘desensitized’ conformations that have a high affinity for the transmitter and no measurable ion conductance. Single-channel currents elicited by 0.1 or 1 mmACh were recorded from human embryonic kidney (HEK) cells that had been transiently transfected with mouse ?, ?, ?, and ? subunits. On the time scale of ?0.1 ms to ?1 h, apparent open intervals are described by a single exponential component, and shut intervals associated with desensitization are described by the sum of four or five exponential components. The kinetic behaviour appeared to be stationary and homogeneous. Desensitization rate constants were estimated by kinetic modelling of currents from cell-attached and outside-out patches (where the number of channels in the patch was measured). A single AChR recovered from the longest-lived desensitized state only after ?5 min. The occupancy of an AChR for each of the desensitized states was calculated as a function of time after the continuous application of a pulse of saturating ACh. The longest-lived desensitized state accounted for 90 % of the total only after several seconds. The fractional recovery from desensitization (during a 200 ms wash period) decreased as the duration of the desensitizing pulse increased, suggesting that recovery is slower from the longer-lived desensitized states. The free energy landscape for the AChR desensitization reaction in cell-attached patches exhibited an initial destabilization, followed by a plateau region of gradually increasing stability, followed by a deep well.

Elenes, Sergio; Auerbach, Anthony



Ultralate cerebral potentials in a patient with hereditary motor and sensory neuropathy type I indicate preserved C-fibre function  

Microsoft Academic Search

Late and ultralate cerebral potentials in response to cutaneous heat (CO2 laser pulses) and electrical nerve stimuli were studied in a patient with hereditary motor and sensory neuropathy type I who showed severe impairment of myelinated nerve fibre function. Cerebral potentials in response to electrical stimuli were absent (tibial nerve) or small (median nerve). With the laser pulses applied to

J Lankers; A Frieling; K Kunze; B Bromm



Plasmapheresis in the Treatment of Ataxic Sensory Neuropathy Associated with Sjögren’s Syndrome  

Microsoft Academic Search

Sjögren’s syndrome (SS) is an important but poorly recognized cause of peripheral neuropathy. Several forms of peripheral nerve dysfunction occur, including trigeminal sensory neuropathy, mononeuropathy multiplex, distal sensorimotor polyneuropathy and pure sensory neuronopathy. The pathological findings vary and the definite treatment is not known. Here we present 4 cases of acute ataxic sensory polyneuropathy with SS, and the experience of

Wei-Hung Chen; Jiann-Horng Yeh; Hou-Chang Chiu



The acute effect of peripheral nerve transection on digital thermoregulatory function  

Microsoft Academic Search

Purpose: This study tests the hypothesis that major peripheral nerves serve as important routes for adrenergic neural fibers and therefore peripheral nerve injury affects cutaneous perfusion within the nerve's sensory innervation territory. The specific aim of the study was to determine whether an acute isolated peripheral nerve injury would result in alteration of blood flow to a specific digit, digital

David S. Ruch; Jeff Vallee; Zhongyu Li; Beth Paterson Smith; Martha Holden; L. Andrew Koman



Trigeminal neuralgia and facial nerve paralysis.  


The trigeminal nerve is the largest of the cranial nerves. It provides sensory input from the face and motor innervation to the muscles of mastication. The facial nerve is the cranial nerve with the longest extracranial course, and its main functions include motor innervation to the muscles of facial expression, sensory control of lacrimation and salivation, control of the stapedial reflex and to carry taste sensation from the anterior two-thirds of the tongue. In order to be able adequately to image and follow the course of these cranial nerves and their main branches, a detailed knowledge of neuroanatomy is required. As we are dealing with very small anatomic structures, high resolution dedicated imaging studies are required to pick up normal and pathologic nerves. Whereas CT is best suited to demonstrate bony neurovascular foramina and canals, MRI is preferred to directly visualize the nerve. It is also the single technique able to detect pathologic processes afflicting the nerve without causing considerable expansion such as is usually the case in certain inflammatory/infectious conditions, perineural spread of malignancies and in very small intrinsic tumours. Because a long course from the brainstem nuclei to the peripheral branches is seen, it is useful to subdivide the nerve in several segments and then tailor the imaging modality and the imaging study to that specific segment. This is particularly true in cases where topographic diagnosis can be used to locate a lesion in the course of these nerves. PMID:15690205

Borges, Alexandra



Inflammatory trigeminal nerve and tract lesions associated with inferior alveolar nerve anaesthesia.  


Inferior alveolar nerve blocks are commonly performed for dental anaesthesia. The procedure is generally safe with a low rate of complications. We report a patient with a reproducible, delayed-onset sensory deficit associated with contrast-enhancing lesions in the trigeminal nerve, pons and medulla following inferior alveolar nerve local anaesthesia. We propose that this previously undescribed condition is a form of Type IV hypersensitivity reaction. PMID:23591181

Blair, N F; Parratt, J D E; Garsia, R; Brazier, D H; Cremer, P D



Effect of desensitizing toothpastes on dentin.  


The objective of this study was to analyze the effects of toothbrushing with desensitizing toothpastes on dentin permeability and dentinal tubule occlusion. Fifty rats provided two hundred incisor teeth divided into five groups: DW, brushed with distilled water (control); FT, brushed with fluoride toothpaste; SCT, brushed with strontium chloride toothpaste; PCT, brushed with potassium citrate toothpaste; and PNT, brushed with potassium nitrate toothpaste. Cavities were prepared to expose the dentinal tubules, and the incisor teeth were brushed using the experimental agents. After each treatment, Evans blue dye solution was applied to the teeth. Dentin permeability was analyzed using scanning electron microscopy and energy-dispersive X-rays (EDX). There were significant differences (p < 0.0001, ANOVA) among the groups regarding dentin permeability, number of dentinal tubules, diameter of dentinal tubules, and opened tubular area. In the SCT, PCT and PNT groups, opened and partially occluded tubules, deposits, and a few smear layers were observed. In the DW and FT groups, most of the dentinal tubules were open, with no deposits or smear layers on the dentin. EDX revealed peaks of calcium and phosphorus in all of the groups, as well as traces of strontium in the SCT group and of potassium in the PCT and PNT groups. Desensitizing toothpaste decreased dentin permeability, although it produced only partial dentin tubule occlusion. PMID:23018228

Pinto, Shelon Cristina Souza; Silveira, Camila Maggi Maia; Pochapski, Márcia Thaís; Pilatt, Gibson Luiz; Santos, Fábio André


[Lipofibromatous hamartoma of the median nerve].  


Lipofibromatous hamartoma of the nerve is a very uncommon, congenital, benign, peripheral nerve tumor. It is mostly encountered in the extremities of young adults, involving the median nerve in the majority of cases. The nerve tissue is infiltrated by diffuse fibroadipose tissue which dissociates the fasciculi without invasion. Patients with lipofibromatous hamartoma of the median nerve usually present with symptoms of carpal tunnel syndrome, usually accompanied by marked macrodactyly. Lipofibromatous hamartoma of the median nerve was encountered in an 18-year-old female patient, involving the wrist, causing macrodactyly of the index finger, and resulting in symptoms of carpal tunnel syndrome. Median nerve release and partial excision of the adipose tissue along the mass were performed. Fourteen months postoperatively, the patient had no complaints and the mass decreased in size without any motor or sensory functional losses. PMID:12510101

Bagatur, A Erdem



Symmetric Lipofibromatous Hamartoma Affecting Digital Nerves  

PubMed Central

Lipofibromatous hamartoma of the nerve is a benign tumor, which affects the major nerves and their branches in the human body. It is often found in the median nerve of the hand and is commonly associated with macrodactyly, but it is rarely found in the digital nerves at the peripheral level. This tumor is often found in young adults and may go through a self-limiting course. However, operation is indicated when the tumor size is large or when the associated nerve compressive symptoms are present. We have experienced a rare case of lipofibromatous hamartoma that symmetrically involved the volar digital nerves of both index fingers on the ulnar side. With the aid of a microscope, we dissected and removed the tumor as much as possible without sacrificing the nerve. No sensory change occurred in both fingers and no sign of recurrence was observed upon follow-up.

Jung, Sung-No; Yim, Youngmin



Topical capsaicin in humans: parallel loss of epidermal nerve fibers and pain sensation  

Microsoft Academic Search

Capsaicin applied topically to human skin produces itching, pricking and burning sensations due to excitation of nociceptors. With repeated application, these positive sensory responses are followed by a prolonged period of hypalgesia that is usually referred to as desensitization, or nociceptor inactivation. Consequently, capsaicin has been recommended as a treatment for a variety of painful syndromes. The precise mechanisms that

Maria Nolano; Donald A Simone; Gwen Wendelschafer-Crabb; Timothy Johnson; Eric Hazen; William R Kennedy



[Applications of 'quantitative sensory testing'].  


Quantitative sensory testing (QST) consists of several non-invasive, standardised tests aimed at examining different aspects of the entire somatosensory nervous system. Important advantages of QST over existing supplementary tests such as electromyography are the ability to test the function of thin and unmyelinated nerve fibres as well as the subjective sensation of a somatosensory stimulus. QST is validated in diagnosing small fibre neuropathy, diabetic neuropathy chemotherapy-induced peripheral neuropathy and neuropathic pain. In scientific research, QST is useful in the study into pathophysiological mechanisms of diseases and syndromes with sensory symptoms and in the evaluation of the effect of analgesic treatment on the function of the somatosensory nervous system. In the future, QST could be a useful diagnostic and prognostic test in more forms of neuropathy and in other clinical conditions such as chronic unexplained pain syndromes (e.g. fibromyalgia and whiplash-associated disorder. PMID:23369816

Verberne, Wouter R; Snijders, Tom J; Liem, K Seng; Baakman, Anne Catrien; Veldhuijzen, Dieuwke S



Sensory perception in overdenture patients.  


The discussion of overdentures has been confined to their capacity to use abutment teeth to improve neuromuscular control of mandibular movement. Use of overdentures has been favored often because of their mechanical advantages, but seldom because of the sensory role of the retained abutment teeth. Even though the retained teeth may be periodontally diseased, they still may provide sufficient support for the transmission of masticatory pressures and sufficient periodontal ligament receptors to initiate a jaw opening reflex. Whereas conflicting evidence shows that the periodontal nerve receptors play a role in mandibular positional sensibility (proprioception), pressure perception by the periodontal ligament remains a primary stimulus for the jaw opening reflex. Additional investigations will be essential to a complete understanding of the role of the periodontal ligament receptors. However, recognition of the importance of the periodontal ligament receptors to the overdenture patient as a source of sensory input is vital. PMID:1066472

Kay, W D; Abes, M S



Nerve and Nerve Root Biomechanics  

Microsoft Academic Search

\\u000a Together, the relationship between the mechanical response of neural tissues and the related mechanisms of injury provide\\u000a a foundation for defining relevant thresholds for injury. The nerves and nerve roots are biologic structures with specific\\u000a and important functions, and whose response to mechanical loading can have immediate, long-lasting and widespread consequences.\\u000a In particular, when nerves or nerve roots are mechanically

Kristen J. Nicholson; Beth A. Winkelstein


[The ulnar nerve compression syndrome].  


The ulnar nerve has to bear a large amount of compression, especially in the cubital tunnel, which can be deducted from the topographic relation of this nerve to the elbow. Apart from tightness of the tunnel, intraarticular changes can also cause compression of the nerve. A further narrow tunnel in the course of the ulnar nerve is the "loge de GUYON", situated in the hypothenar region. A careful neurological examination of sensory and motor signs as well as an accurate electromyographical examination differentiate compression syndromes from other neuropathies. Two unusual cases of a functional cubital tunnel syndrome are demonstrated: their cause was primarily a chondromatosis of the elbow joint in one case a functional vasal compression in the other case. PMID:7250791

Thümler, P; Goymann, V



Effects of precementation desensitizing laser treatment and conventional desensitizing agents on crown retention.  


This study aimed to compare the effect of precementation desensitizing laser treatment and conventional desensitizing agents on crown retention. Crowns were fabricated for 50 molar teeth, and specimens were assigned to 5 groups based on treatment method: untreated control group (CON), laser group (LAS), sodium fluoride group (FLU), Oxagel oxalate group (OXA), and Gluma primer group (GLU). All crowns were luted with glass-ionomer cement. Tensile force was applied for crown dislodgement. Recorded forces and calculated retentive strengths were as follows: CON (261 N) > LAS (223 N) = FLU (208 N) > GLU (161 N) = OXA (147 N) (P < .05). The differences in force magnitudes between all groups were significant (P < .05), except for LAS versus FLU and GLU versus OXA. The retention decrease was 15% for LAS, 20% for FLU, 38% for GLU, and 44% for OXA. Laser treatment had a less negative effect on retention for crowns luted with glass-ionomer cement than the other treatment modalities, and it may be a more suitable desensitization method if crown retention can be moderately sacrificed. PMID:17580462

Sipahi, Cumhur; Cehreli, Murat; Ozen, Julide; Dalkiz, Mehmet


Nerve Conduction Study Among Healthy Malays. The Influence of Age, Height and Body Mass Index on Median, Ulnar, Common Peroneal and Sural Nerves  

PubMed Central

Nerve conduction study is essential in the diagnosis of focal neuropathies and diffuse polyneuropathies. Age, height and body mass index (BMI) can affect nerve velocities as reported by previous studies. We studied the effect of these factors on median, ulnar, common peroneal and sural nerves among healthy Malay subjects. We observed slowing of nerve conduction velocities (NCVs) with increasing age and BMI (except ulnar sensory velocities). No demonstrable trend can be seen across different height groups except in common peroneal nerve.

Awang, Mohamed Saufi; Abdullah, Jafri Malin; Abdullah, Mohd Rusli; Tharakan, John; Prasad, Atul; Husin, Zabidi Azhar; Hussin, Ahmad Munawir; Tahir, Adnan; Razak, Salmi Abdul



Warmth suppresses and desensitizes damage-sensing ion channel TRPA1  

PubMed Central

Background Acute or chronic tissue damage induces an inflammatory response accompanied by pain and alterations in local tissue temperature. Recent studies revealed that the transient receptor potential A1 (TRPA1) channel is activated by a wide variety of substances that are released following tissue damage to evoke nociception and neurogenic inflammation. Although the effects of a noxious range of cold temperatures on TRPA1 have been rigorously studied, it is not known how agonist-induced activation of TRPA1 is regulated by temperature over an innocuous range centred on the normal skin surface temperature. This study investigated the effect of temperature on agonist-induced currents in human embryonic kidney (HEK) 293 cells transfected with rat or human TRPA1 and in rat sensory neurons. Results Agonist-induced TRPA1 currents in HEK293 cells were strongly suppressed by warm temperatures, and almost abolished at 39°C. Such inhibition occurred when TRPA1 was activated by either electrophilic or non-electrophilic agonists. Warming not only decreased the apparent affinity of TRPA1 for mustard oil (MO), but also greatly enhanced the desensitization and tachyphylaxis of TRPA1. Warming also attenuated MO-induced ionic currents in sensory neurons. These results suggest that the extent of agonist-induced activity of TRPA1 may depend on surrounding tissue temperature, and local hyperthermia during acute inflammation could be an endogenous negative regulatory mechanism to attenuate persistent pain at the site of injury. Conclusion These results indicate that warmth suppresses and desensitizes damage-sensing ion channel TRPA1. Such warmth-induced suppression of TRPA1 may also explain, at least in part, the mechanistic basis of heat therapy that has been widely used as a supplemental anti-nociceptive approach.



Effectiveness of Different Methods of Specific Desensitization by Microbial Allergens.  

National Technical Information Service (NTIS)

The significance of microbial allergy with bronchial asthma is recognized by many researchers. Several widely accepted methods for sepcific desensitization by microbial antigens are examined. The following types of microbial antigens were employed: 'solub...

G. A. Dashtayants Y. N. Sidorenko



Phosphorylation-Independent Desensitization of G Protein-Coupled Receptors?  

NSDL National Science Digital Library

G protein-coupled receptors (GPCRs) are involved in a multitude of signaling processes and respond to a wide range of ligands. The activity of GPCRs is subject to three principal modes of regulation: desensitization, trafficking, and down-regulation. Desensitization is defined as a loss in the responsiveness of a signaling system. The generally established paradigm for GPCR desensitization involves receptor phosphorylation by GPCR kinases (GRKs), initiated by agonist-induced conformational changes in the receptor or by kinases activated by specific signaling pathways. GRKs have several interaction domains and may be able to contribute to receptor desensitization through mechanisms that do not involve the kinase activity of GRK. Pao and Benovic discuss some of these interactions and their relevance for the regulation of GPCR signaling.

Christina S. Pao (Thomas Jefferson University;The Kimmel Cancer Center, Department of Microbiology and Immunology REV); Jeffrey L. Benovic (Thomas Jefferson University;The Kimmel Cancer Center, Department of Microbiology and Immunology REV)



Sensory Integration Dysfunction  

Microsoft Academic Search

\\u000a Sensory integration dysfunction (SID) (also known as regulatory sensory processing disorder, sensory processing dysfunction,\\u000a or sensory processing dysfunction) is a neurological disorder that involves impairment in processing data from the different\\u000a senses (vision, auditory, touch, olfaction, and taste), the vestibular system (movement), and proprioception (body awareness).

Mark L. Goldstein; Stephen Morewitz


Cytotoxic effects of dental desensitizers on human gingival fibroblasts.  


The purpose of this study was to evaluate the effects of three different desensitizers on the cell viability and morphology of human gingival fibroblasts (HGF). Human gingival tissues were obtained from individuals who have clinically, healthy periodontium. HGF were grown at 37 degrees C in humidified atmosphere of 5% CO2 in Dulbecco's modified eagle's medium, supplemented with glutamine, penicillin, streptomycin, and 10% fetal bovine serum. The cells were treated with different concentrations (0.1, 0.3, and 0.5 microL/mL) of desensitizers (Gluma Desensitizer, Seal&Protect, and MicroPrime). After 24- and 48-h exposure to the desensitizer solutions, the viable cells were examined using a hemocytometer. To monitor HGF viability, 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl tetrazolium bromide (MTT) colorimetric assay was used and cell morphology was also observed at 48 h. Following exposure to concentrations of 0.1 microL/mL of test materials for 24 h, cell survival rates for Gluma Desensitizer (106%) and Micro Prime (62%) were not significantly different from the control, while it was significant for Seal&Protect (50%). Growing cells were significantly inhibited by all tested materials for 48 h (p < 0.05) in survival rates of 51, 47, and 31%, respectively. On the basis of the MTT assay, the cytotoxic effect of MicroPrime was more prominent, especially at high concentrations, than does Gluma Desensitizer and Seal&Protect. After exposure to Seal&Protect and MicroPrime, HGF became retracted, rounded in appearance and had loss of normal organization, leading to enlargement of intercellular space when compared with Gluma Desensitizer. As a conclusion, taking the limitations of an in vitro experiment into consideration, the cytotoxic effects were varied, depending on the chemical composition and exposure periods of the tested desensitizers. PMID:16470823

Sengun, A; Buyukbas, S; Hakki, S S



Changes in nociceptive sensory innervation in the epidermis of the rat lower lip skin in a model of neuropathic pain  

Microsoft Academic Search

The epidermis is innervated by fine nerve endings that are important in the perception of nociceptive stimuli. However, their role in neuropathic pain is controversial. In this paper, changes in the innervation patterns of epidermal sensory afferent fibres in the rat lower lip have been studied following bilateral chronic constriction injury (CCI) of the mental nerve—a purely sensory branch of

C. Grelik; S. Allard; A. Ribeiro-da-Silva



Control of neural interfacing in peripheral nerves through regenerative molecular guidance  

Microsoft Academic Search

Regenerative peripheral nerve interfaces have been proposed as viable alternatives for the natural control of robotic prosthetic devices. However, random axonal pathfinding during peripheral nerve regeneration leads to mixed populations of sensory and motor neurons at the electrode interfaces preventing the precise identification of the modality nature of the recorded action potentials; motor or specific sensory sub-modalities. This study present

Parisa Lotfi; Mario I. Romero-Ortega



The non-linear relationship between nerve conduction velocity and skin temperature  

Microsoft Academic Search

Median motor and sensory nerves were examined in 20 healthy subjects. Superficial stimulating and recording electrodes were used, and the nerves were examined at natural skin temperature, after cooling and after heating of the arm. The conduction velocity for the fastest and slow conducting sensory fibres (temperature range 17-37 degrees C), and for the fastest conducting motor fibres (temperature range

K Todnem; G Knudsen; T Riise; H Nyland; J A Aarli



Nerve Growth Factor of Red Nucleus Involvement in Pain Induced by Spared Nerve Injury of the Rat Sciatic Nerve  

Microsoft Academic Search

Nerve growth factor (NGF), a member of the neurotrophin family, is essential for the development and maintenance of sensory\\u000a neurons and for the formation of central pain circuitry. The current study was designed to evaluate the expression of NGF\\u000a in the brain of rats with spared nerve injury (SNI), using immunohistochemical technique. The results showed that the level\\u000a of NGF

Yuan-Yuan Jing; Jun-Yang Wang; Xiao-Li Li; Zhi-Hong Wang; Liu Pei; Ming-Ming Pan; Xiao-Ping Dong; Gui-Xiang Fan; Yu-Kang Yuan



Activin is a nerve cell survival molecule  

Microsoft Academic Search

THE structures of five neurotrophic molecules have so far been published. Nerve growth factor1, fibroblast growth factor2, 3 and purpurin4, have been identified as nerve-cell survival molecules. More recently, brain-derived neurotrophic factor (BDNF) and ciliary neurotrophic factor have been cloned and sequenced5, 6. As all these proteins stimulate the survival of ciliary or sensory neurons, a new cell survival assay

D. Schubert; H. Kimura; M. Lacorbiere; J. Vaughan; D. Karr; W. H. Fischer



Quantitative Assessment of the Motor-Sensory Specificity of the Motor and Primary Sensory Neurons after the End-to-Side Neurorrhaphy.  


We sought to evaluate the motor-sensory specificity of the motor and primary sensory neurons after the end-to-side neurorrhaphy. We divided 90 rats into three groups: (1) end-to-side neurorrhaphy using the ulnar nerve as donor nerve and the musculocutaneous nerve as recipient nerve; (2) normal control; and (3) transected nerve with the stumps buried. At 5 months, we monitored the grooming test, the electromyographic recordings, the histologic changes in the nerve, and quantitatively evaluated motoneurons and dorsal root ganglion (DRG) neurons following their retrograde labeling by Fluoro-Gold (Sigma, St. Louis, MO) applied to the musculocutaneous nerve and its biceps brachii branch. Grooming and electrophysiological investigations recovered successfully in the end-to-side group. The implanted musculocutaneous nerve contained varying but satisfactory numbers of axons. In the end-to-side group, the proportion of motoneurons for the biceps brachii branch of musculocutaneous nerve was very similar to the musculocutaneous nerve sections proximal to this branch (17.3% ± 2.7% and 21.7% ± 3.7%, respectively), but it did not correspond with the proportion of the biceps brachii branch of musculocutaneous nerve in the normal group (28.3% ± 3.5%). The present study confirms that limited but functional reinnervation can occur after the end-to-side neurorrhaphy, and the motor-sensory specificity is not important. PMID:23757157

Yu, Qing; Chen, Chengwang; Zhang, Xiaolei; Lv, Lei; Lin, Kang; Chi, Yonglong; Gao, Weiyang



Anterograde transneuronal viral tract tracing reveals central sensory circuits from brown fat and sensory denervation alters its thermogenic responses  

PubMed Central

Brown adipose tissue (BAT) thermogenic activity and growth are controlled by its sympathetic nervous system (SNS) innervation, but nerve fibers containing sensory-associated neuropeptides [substance P, calcitonin gene-related peptide (CGRP)] also suggest sensory innervation. The central nervous system (CNS) projections of BAT afferents are unknown. Therefore, we used the H129 strain of the herpes simplex virus-1 (HSV-1), an anterograde transneuronal viral tract tracer used to delineate sensory nerve circuits, to define these projections. HSV-1 was injected into interscapular BAT (IBAT) of Siberian hamsters and HSV-1 immunoreactivity (ir) was assessed 24, 48, 72, 96, and 114 h postinjection. The 96- and 114-h groups had the most HSV-1-ir neurons with marked infections in the hypothalamic paraventricular nucleus, periaqueductal gray, olivary areas, parabrachial nuclei, raphe nuclei, and reticular areas. These sites also are involved in sympathetic outflow to BAT suggesting possible BAT sensory-SNS thermogenesis feedback circuits. We tested the functional contribution of IBAT sensory innervation on thermogenic responses to an acute (24 h) cold exposure test by injecting the specific sensory nerve toxin capsaicin directly into IBAT pads and then measuring core (Tc) and IBAT (TIBAT) temperature responses. CGRP content was significantly decreased in capsaicin-treated IBAT demonstrating successful sensory nerve destruction. TIBAT and Tc were significantly decreased in capsaicin-treated hamsters compared with the saline controls at 2 h of cold exposure. Thus the central sensory circuits from IBAT have been delineated for the first time, and impairment of sensory feedback from BAT appears necessary for the appropriate, initial thermogenic response to acute cold exposure.

Vaughan, Cheryl H.



Impact of Peripheral Nerve Injury on Sensorimotor Control  

Microsoft Academic Search

Deficits in sensorimotor control are experienced immediately after nerve injury due to changes in the periphery and central nervous system. Muscle denervation and sensory loss often disrupt prehensile coordination requiring the use of alternative strategies. To effectively foster coordination postinjury clinicians should address not only impairments and function but motor control issues through the prescription of specific sensory and motor

Susan V. Duff



The consistent presence of the human accessory deep peroneal nerve  

PubMed Central

Twenty-four human legs were dissected macroscopically to study the morphological details of the accessory deep peroneal nerve. This nerve arose from the superficial peroneal nerve and descended in the lateral compartment of the leg, deep to peroneus longus along the posterior border of peroneus brevis. Approaching the ankle joint, this nerve passed through the peroneal tunnels to wind around the lateral malleolus; it then crossed beneath the peroneus brevis tendon anteriorly to reach the dorsum of the foot. The accessory deep peroneal nerve was found in every case examined and constantly gave off muscular branches to peroneus brevis and sensory branches to the ankle region. In addition, this nerve occasionally had muscular branches to peroneus longus and extensor digitorum brevis, and sensory branches to the fibula and the foot. The anomalous muscles around the lateral malleolus were also innervated by this nerve. Neither cutaneous branches nor communicating branches with other nerves were found. The present study reveals that the accessory deep peroneal nerve is consistently present and possesses a proper motor and sensory distribution in the lateral region of the leg and ankle. It is not an anomalous nerve as has previously been suggested.




Mechanism of action of a desensitizing fluoride toothpaste delivering calcium and phosphate ingredients in the treatment of dental hypersensitivity. Part II: comparison with a professional treatment for tooth hypersensitivity.  


Tooth hypersensitivity can occur when gum recession causes exposure of dentin. Tiny tubules, which permeate dentin, provide open passageways from the mouth to the intradental nerve in the pulpal cavity. Under such circumstances, stimuli in the mouth can cause pressure on the intradental nerve, leading to pain. Sealing the outside of the tubules with an impermeable substance can effectively treat hypersensitivity. One such clinically proven composition is a professionally applied tooth desensitizer, which has been shown to initially produce a layer of amorphous calcium phosphate (ACP) on the surface of dentin. Under the influence of fluoride, ACP reforms as hydroxyapatite (HAP), which has essentially the same composition as tooth mineral. Three fluoride toothpastes that deliver calcium and phosphate salts to the teeth also have been demonstrated in clinical trials to relieve hypersensitivity. This study compared the mechanism of action of these toothpastes to that of the professional desensitizer. A single application of the professional desensitizer or multiple applications of any of the three toothpastes was shown to reduce dentin permeability. A conventional fluoride toothpaste also was found to inhibit fluid flow through the dentin but to a lesser degree than the other toothpastes. The desensitizer and the three toothpastes were found to occlude the dentinal tubules with a layer of calcium phosphate that had a calcium-to-phosphate ratio consistent with the formation of ACP or HAP. The morphology of the coherent mineral layer formed by Arm & Hammer Enamel Care Sensitive was similar, especially to that produced by the desensitizer. In contrast, the conventional toothpaste left localized areas of surface residue composed of silica particles. The mechanism of action of the three toothpastes that deliver calcium and phosphate salts is the same as that of the professional desensitizer. PMID:19998729

Charig, Andrew J; Thong, Stephen; Flores, Florita; Gupta, Shivank; Major, Elizabeth; Winston, Anthony E


The Structure of the Ventral Nerve Cord of Caenorhabditis elegans  

Microsoft Academic Search

The nervous system of Caenorhabditis elegans is arranged as a series of fibre bundles which run along internal hypodermal ridges. Most of the sensory integration takes place in a ring of nerve fibres which is wrapped round the pharynx in the head. The body muscles in the head are innervated by motor neurones in this nerve ring while those in

J. G. White; Eileen Southgate; J. N. Thomson; S. Brenner



Recovery of two-point discrimination function after digital nerve repair in the hand using resorbable FDA- and CE-approved nerve conduits.  


This article aims to provide an overview of all clinical studies reporting sensory outcome as measured by two-point discrimination after digital nerve repair in the hand using resorbable Food and Drug Administration (FDA)- and CE-approved nerve conduits. The minimum follow-up for inclusion in this review was 11 months. In total, 235 nerve reconstructions could be classified. A total of 169 (72%) nerve reconstructions with a synthetic polyester-based nerve conduit were included; the other 66 nerves were reconstructed with collagen-based nerve conduits. To obtain the most reliable and comparable data, outcomes of each study were reclassified in the classification system as was used in the first two prospective randomised multicentre studies on the use of resorbable nerve conduits for repair of digital nerve gaps in the hand. Of the 235 nerve reconstructions, 171 (73%) nerve reconstructions showed good to excellent functional outcome. As many as 64 (27%) of the nerve reconstructions had a poor outcome. Based on the available data in this article at this moment, we conclude that digital nerve gaps up to 4 cm can be bridged by resorbable nerve conduits with a sensory outcome that can be qualified as good to excellent in almost 75% of cases after 11 months. Differences between FDA- and CE-approved nerve conduits could not be detected, apart from the rates of protrusion that were not observed using collagen-based nerve conduits. PMID:23827446

Meek, Marcel F; Coert, J Henk



The Trigeminal (V) and Facial (VII) Cranial Nerves  

PubMed Central

There are close functional and anatomical relationships between cranial nerves V and VII in both their sensory and motor divisions. Sensation on the face is innervated by the trigeminal nerves (V) as are the muscles of mastication, but the muscles of facial expression are innervated mainly by the facial nerve (VII) as is the sensation of taste. This article briefly reviews the anatomy of these cranial nerves, disorders of these nerves that are of particular importance to psychiatry, and some considerations for differential diagnosis.

Sanders, Richard D.



Compression neuropathy of the radial palmar thumb nerve.  


Compression neuropathy of a single digital nerve is a rare entity. We report the case of a patient with numbness in the distribution of the radial digital nerve of the thumb caused by the use of a walking stick. The nerve was compressed between the handle of the stick, the loop and the radial sesamoid bone of the first metacarpophalangeal joint. The site of the lesion was confirmed by electrophysiologic examination. Orthodromic recording of the sensory response from the radial palmar digital nerve of the thumb documented a complete absence of nerve action potential whereas the ulnar digital thumb nerve showed a normal response. Sensory function was restored when a padded ski glove was used to protect the area of the metacarpophalangeal joint whilst using the stick. PMID:15071968

Hug, U; Burg, D; Baldi, S V; Meyer, V E



Not all desensitizations are created equal: Physiological evidence that AMPA receptor desensitization differs for kainate and glutamate  

PubMed Central

AMPA receptor mediated responses to the agonist kainate differ from those of glutamate in two important respects. Glutamate is a full agonist that elicits strongly desensitizing responses while kainate is a partial agonist with responses that are often described as weakly- or non-desensitizing. The efficacy of kainate relative to glutamate has previously been shown to be increased by mutations in the AMPA receptor ligand-binding cleft (Mano et al., 1996) and by co-expression with the auxiliary subunit stargazin (Tomita et al., 2005; Turetsky et al., 2005), but much less is known about factors that affect kainate desensitization. We therefore designed experiments to compare kainate and glutamate desensitization and efficacy in wild-type and mutant AMPA receptors expressed with and without stargazin in HEK293 cells. Desensitization to the two agonists was differentially affected by mutations in the helices participating in bonds between two subunits in the active state of the receptor (Sun et al.,2002), indicating that the protein interactions maintaining the stability of the dimer interface differ depending on which agonist is bound. Kainate efficacy was affected by factors distinct from ligand-binding cleft closure, including mutations in the dimer interface and channel vestibule as well as receptor composition. The increase in kainate responses for AMPA receptors co-expressed with stargazin was the result of both reduced kainate desensitization and increased kainate efficacy. These results provide critical new insights into the agonist-dependence of both AMPA receptor activation and desensitization and the mechanism of stargazin’s effects on responses of partial agonists.

Levchenko-Lambert, Yanina; Turetsky, Dorothy M.; Patneau, Doris K.



The effect of cyclophosphamide and role suppressor cells in the desensitization of delayed hypersensitivity.  

PubMed Central

Desensitization of guinea-pigs with ovalbumin (OA) or bovine gamma globulin (BGG) induces strong specific desensitization and is associated with a non-specific energy to tuberculin--PPD. Similarly, it was found that animals receiving desensitizing injections of PPD have suppressed delayed hypersensitivity reactions to OA or BGG. PPD also induced strong specific desensitization. Cyclophosphamide (CY) given in one large dose (300 mg/kg) 3 days before immunization failed to affect the specific desensitization induced by all three antigens. However, if CY was given 1 day after immunization, it was not possible to induce specific desensitization. The induction of non-specific desensitization was prevented in all three antigen systems if CY was given either 3 days before or 1 day after immunization. Desensitization with either OA or BGG markedly suppressed the specific 4 hr Arthus reactions.

Parker, D; Dwyer, J M; Turk, J L



Ultrasound guidance for the performance of sciatic and saphenous nerve blocks in dogs.  


The aim of this study was to investigate the use of ultrasound (US) guidance to perform sciatic and saphenous nerve blocks in dogs. Five dogs were sedated with medetomidine and butorphanol. A high-resolution US transducer was used to locate the nerves, guide placement of the needle and visualise the perineural injection of lidocaine 2%. Electrostimulation was used to confirm correct placement prior to the sciatic block. Nerve functions were evaluated over a 3 h period following administration of atipamezole. Successful identification of the nerves and the quality of the blocks were recorded. Location of the nerves, complete sensory block of the saphenous nerve, and partial to complete sensory and motor blocks of the sciatic nerve were achieved in all dogs. The resultant US guidance is potentially valuable for blocking the sciatic and saphenous nerves in dogs, although further work will be required to ensure a complete block of the sciatic nerve. PMID:19919902

Costa-Farré, Cristina; Blanch, Xavier Sala; Cruz, J Ignacio; Franch, Jordi



Desensitization of mechano-gated K2P channels.  


The neuronal mechano-gated K2P channels TREK-1 and TRAAK show pronounced desensitization within 100 ms of membrane stretch. Desensitization persists in the presence of cytoskeleton disrupting agents, upon patch excision, and when channels are expressed in membrane blebs. Mechanosensitive currents evoked with a variety of complex stimulus protocols were globally fit to a four-state cyclic kinetic model in detailed balance, without the need to introduce adaptation of the stimulus. However, we show that patch stress can be a complex function of time and stimulation history. The kinetic model couples desensitization to activation, so that gentle conditioning stimuli do not cause desensitization. Prestressing the channels with pressure, amphipaths, intracellular acidosis, or the E306A mutation reduces the peak-to-steady-state ratio by changing the preexponential terms of the rate constants, increasing the steady-state current amplitude. The mechanical responsivity can be accounted for by a change of in-plane area of approximately 2 nm2 between the closed and open conformations. Desensitization and its regulation by chemical messengers is predicted to condition the physiological role of K2P channels. PMID:16636285

Honoré, Eric; Patel, Amanda Jane; Chemin, Jean; Suchyna, Thomas; Sachs, Frederick



Electrostatic interactions regulate desensitization of the nicotinic acetylcholine receptor.  

PubMed Central

To determine the importance of electrostatic interactions for agonist binding to the nicotinic acetylcholine receptor (AChR), we examined the affinity of the fluorescent agonist dansyl-C6-choline for the AChR. Increasing ionic strength decreased the binding affinity in a noncompetitive manner and increased the Hill coefficient of binding. Small cations did not compete directly for dansyl-C6-choline binding. The sensitivity to ionic strength was reduced in the presence of proadifen, a noncompetitive antagonist that desensitizes the receptor. Moreover, at low ionic strength, the dansyl-C6-choline affinities were similar in the absence or presence of proadifen, a result consistent with the receptor being desensitized at low ionic strength. Similar ionic strength effects were observed for the binding of the noncompetitive antagonist [(3)H]ethidium when examined in the presence and absence of agonist to desensitize the AChR. Therefore, ionic strength modulates binding affinity through at least two mechanisms: by influencing the conformation of the AChR and by electrostatic effects at the binding sites. The results show that charge-charge interactions regulate the desensitization of the receptor. Analysis of dansyl-C6-choline binding to the desensitized conformation using the Debye-Hückel equation was consistent with the presence of five to nine negative charges within 20 A of the acetylcholine binding sites.

Song, X Z; Pedersen, S E



Desensitization of the nicotinic acetylcholine receptor: Molecular mechanisms and effect of modulators  

Microsoft Academic Search

1.Loss of response after prolonged or repeated application of stimulus is generally termed desensitization. A wide variety of phenomena occurring in living organisms falls under this general definition of desensitization. There are two main types of desensitization processes: specific and non-specific.2.Desensitization of the nicotinic acetylcholine receptor is triggered by prolonged or repeated exposure to agonists and results in inactivation of

Enrique L. M. Ochoa; Amitabha Chattopadhyay; Mark G. McNamee



Adding a Selective Obturator Nerve Block to the Parasacral Sciatic Nerve Block: An Evaluation  

Microsoft Academic Search

Our aim was to objectively evaluate the efficacy of ob- turator nerve anesthesia after a parasacral block. Pa- tientsscheduledforkneesurgeryhadabaselineadduc- tor strength evaluation. After a parasacral block with 30 mL 0.75% ropivacaine, sensory deficit in the sciatic distribution (temperature discrimination) and adduc- tor strength were assessed at 5-min intervals. Patients with an incomplete sensory block (defined as a temper- ature discrimination

Denis Jochum; Gabriella Iohom; Olivier Choquet; Dioukamady Macalou; Samba Ouologuem; Pascal Meuret; Freddy Kayembe; Michel Heck; Paul-Michel Mertes



Electrophysiology of corneal cold receptor nerve terminals.  


The mechanisms of sensory transduction in the fine nerve terminals of free nerve endings supplied by Adelta and C sensory axons are largely a matter of speculation. This is because the nerve terminals are small and inaccessible, particularly in intact tissues like skin. However, some of the difficulties associated with investigating the physiology of fine nerve terminals have recently been overcome using an in vitro preparation of the guinea-pig cornea that allows nerve terminal impulses (NTIs) to be recorded extracellularly from single polymodal and cold receptor nerve terminals. For cold receptors, the rate of spontaneously occurring NTIs is increased during cooling and decreased during heating. In addition, heating and cooling differentially modulate the shape of the recorded NTI. At the same temperature, NTIs are larger in amplitude and faster in time course during heating than those during cooling. The differential effect of heating and cooling on NTI shape is not considered to result simply from the temperature dependence of voltage-activated conductance kinetics or activity dependent changes in membrane excitability. Instead, changes in NTI shape may reflect changes in nerve terminal membrane potential that underlie the process of thermal transduction. PMID:12171110

Carr, Richard W; Brock, James A



Alterations in peripheral nerves of rats treated with chlorphentermine or with iprindole  

Microsoft Academic Search

This study deals with the effects of two amphiphilic lipidosis-inducing drugs (chlorphentermine, iprindole) upon the ultrastructure of peripheral nerves of rats. After prolonged drug treatment the preterminal and terminal axoplasm of motor and sensory nerves within skeletal muscles contain numerous abnormal inclusions (osmiophilic conglomerates, autophagic vacuoles, lamellated bodies). By contrast, the axons within large peripheral nerves are little affected. The

Detlev Drenckhahn; Renate Lfillmann-Rauch



Inferior alveolar nerve paresthesia caused by endodontic pathosis: A case report and review of the literature  

Microsoft Academic Search

Sensory disturbances such as anesthesia, hypoesthesia, hyperesthesia, and paresthesia may be present in the oral cavity, stemming from many local and systemic factors. Paresthesia of the inferior alveolar nerve is quite rare because of the unique anatomy of this nerve. Among other effects, periapical lesions can damage the nerve, resulting in paresthesia of its innervated area. Only a few cases

Michele Giuliani; Carlo Lajolo; Giorgio Deli; Caterina Silveri



Fetal sensory competencies  

Microsoft Academic Search

A growing body of evidence is available about the functioning of fetal sensory systems during gestation. This article aims at reviewing data concerning (i) the presence of potential sensory stimulation in the fetal milieu, (ii) the sequential functional development of the sensory systems and (iii) physiological and behavioral responses of fetuses to various types of stimulation. Human data are compared

Jean-Pierre Lecanuet; Benoist Schaal



Sensory Assessment Manual.  

ERIC Educational Resources Information Center

|This manual is intended to provide information leading to reliable assessment of vision and hearing capabilities of children considered to have dual sensory impairments. Ongoing sensory assessment is necessary to determine the extent of residual sensory abilities that should be considered in educational programming decisions and to determine any…

Cress, Pamela J.


Pinched Nerve  


... take about one hour: Nerve conduction study. Patch-style electrodes are placed on your skin to stimulate ... not-for-profit organization and proceeds from Web advertising help support our mission. Mayo Clinic does not ...


Convergence of cervical and trigeminal sensory afferents.  


Cranial nociceptive perception shows a distinct topographic distribution, with the trigeminal nerve receiving sensory information from the anterior portions of the head, the greater occipital nerve, and branches of the upper cervical roots in the posterior regions. However, this distribution is not respected during headache attacks, even if the etiology of the headache is specific for only one nerve. Nociceptive information from the trigeminal and cervical territories activates the neurons in the trigeminal nucleus caudalis that extend to the C2 spinal segment and lateral cervical nucleus in the dorsolateral cervical area. These neurons are classified as multimodal because they receive sensory information from more than one afferent type. Clinically, trigeminal activation produces symptoms in the trigeminal and cervical territory and cervical activation produces symptoms in the cervical and trigeminal territory. The overlap between the trigeminal nerve and cervical is known as a convergence mechanism. For some time, convergence mechanisms were thought to be secondary to clinical observations. However, animal studies and clinical evidence have expanded our knowledge of convergence mechanisms. In this paper, the role of convergence mechanisms in nociceptive physiology, physiopathology of the headaches, clinical diagnosis, and therapeutic conduct are reviewed. PMID:12946291

Piovesan, Elcio J; Kowacs, Pedro A; Oshinsky, Michael L



Inducing assertive behavior in chronic schizophrenics: A comparison of socioenvironmental, desensitization, and relaxation therapies  

Microsoft Academic Search

Assigned 63 20-67 yr. old male schizophrenics to 3 treatment conditions: socioenvironmental treatment, systematic desensitization, or relaxation training. It was predicted that socioenvironmental treatment would be more effective with older male schizophrenics (over 45 yr. of age) and systematic desensitization and relaxation training with younger male schizophrenics in generating assertive behavior. It was further anticipated that systematic desensitization and relaxation

Bernard Weinman; Peter Gelbart; Mary Wallace; Maureen Post



Desensitization of Chemical Activation by Auxiliary Subunits  

PubMed Central

Chemical openers for KCNQ potassium channels are useful probes both for understanding channel gating and for developing therapeutics. The five KCNQ isoforms (KCNQ1 to KCNQ5, or Kv7.1 to Kv7.5) are differentially localized. Therefore, the molecular specificity of chemical openers is an important subject of investigation. Native KCNQ1 normally exists in complex with auxiliary subunits known as KCNE. In cardiac myocytes, the KCNQ1-KCNE1 (IsK or minK) channel is thought to underlie the IKs current, a component critical for membrane repolarization during cardiac action potential. Hence, the molecular and pharmacological differences between KCNQ1 and KCNQ1-KCNE1 channels have been important topics. Zinc pyrithione (ZnPy) is a newly identified KCNQ channel opener, which potently activates KCNQ2, KCNQ4, and KCNQ5. However, the ZnPy effects on cardiac KCNQ1 potassium channels remain largely unknown. Here we show that ZnPy effectively augments the KCNQ1 current, exhibiting an increase in current amplitude, reduction of inactivation, and slowing of both activation and deactivation. Some of these are reminiscent of effects by KCNE1. In addition, neither the heteromultimeric KCNQ1-KCNE1 channels nor native IKs current displayed any sensitivity to ZnPy, indicating that the static occupancy by a KCNE subunit desensitizes the reversible effects by a chemical opener. Site-directed mutagenesis of KCNQ1 reveals that residues critical for the potentiation effects by either ZnPy or KCNE are clustered together in the S6 region overlapping with the critical gating determinants. Thus, the convergence of potentiation effects and molecular determinants critical for both an auxiliary subunit and a chemical opener argue for a mechanistic overlap in causing potentiation.

Gao, Zhaobing; Xiong, Qiaojie; Sun, Haiyan; Li, Min




Microsoft Academic Search

The effects of clenbuterol in preserving the form and function of muscle after unilateral sciatic nerve division and epineural repair were investigated in a rat model. The drug (a ?2-adrenoceptor agonist) was administered daily for six weeks by gastric gavage (10 ?g\\/kg body weight), interrupted every 5 days by a 2 day omission of dosing to avoid drug desensitization. Clenbuterol




A new composite midface allotransplantation model with sensory and motor reinnervation.  


In this study, we extended application of face transplantation model in rat by incorporation of vascularized premaxilla, and nose with infraorbital and facial nerves for evaluation of allotransplanted sensory and motor nerve functional recovery. In group I (n = 3) the dissection technique is studied. In group II (n = 5) isotransplantations were performed. In group III (n = 5) allotransplantations were performed under Cyclosporin A monotherapy. Grafts; composed of nose, lower lip, and premaxilla; were dissected. Infraorbital nerve and facial nerve were included into the transplant. A heterotopic transplantation was performed to inguinal region of recipient. Nerve coaptations were performed between infraorbital-sapheneous nerve and facial-femoral nerve. CT scan, somatosensory-evoked potential testing (SSEP), motor-evoked potential testing (MEP), and microangiography were used for evaluation. All transplants survived indefinitely over 100 days. Microangiography showed preserved vascularization of the graft. Computed tomography revealed vital premaxillary bone segments. SSEP and MEP confirmed recovery of motor and sensory functions and latencies reached 67% of normal infraorbital nerve value and 70% of normal facial nerve value at 100 days post-transplant. We have introduced new midface transplant model of composite midface allograft with sensory and motor units. In this model, motor and sensory functional recovery was confirmed at 100 days post-transplant. PMID:20028492

Zor, Fatih; Bozkurt, Mehmet; Nair, Dileep; Siemionow, Maria



[Sensory innervation of the bladder: clinical and therapeutic implications].  


Sensory impulses derived from the bladder and urinary sphincter system play an important role in the control of detrusor-sphincter function. Conscious sensation is essential to ensure the storage phase and to allow micturition at a functionally and socially acceptable time. Adequate sensation of the lower urinary tract requires an intact urothelium--peripheral nervous system--spinal cord--brain stem--midbrain--sensory cortex axis. This article reviews the current anatomical, physiological and pathophysiological knowledge concerning the afferent (sensory) nerve pathways of the bladder and urethra, with particular emphasis on their physiological and therapeutic implications. PMID:17373230

Comperat, Eva; Reitz, André; Mozer, Pierre; Robain, Gilberte; Denys, Pierre; Chartier-Kastler, Emmanuel



Eye movement desensitization and reprocessing: a conceptual framework.  


Eye movement desensitization and reprocessing (EMDR) is a method which was initially used for the treatment of post-traumatic stress disorder. But it is now being used in different therapeutic situations. EMDR is an eight-phase treatment method. History taking, client preparation, assessment, desensitization, installation, body scan, closure and reevaluation of treatment effect are the eight phases of this treatment which are briefly described. A case report is also depicted which indicates the efficacy of EMDR. The areas where EMDR is used and the possible ways through which it is working are also described. PMID:21716864

Menon, Sukanya B; Jayan, C



Eye Movement Desensitization and Reprocessing: A Conceptual Framework  

PubMed Central

Eye movement desensitization and reprocessing (EMDR) is a method which was initially used for the treatment of post-traumatic stress disorder. But it is now being used in different therapeutic situations. EMDR is an eight-phase treatment method. History taking, client preparation, assessment, desensitization, installation, body scan, closure and reevaluation of treatment effect are the eight phases of this treatment which are briefly described. A case report is also depicted which indicates the efficacy of EMDR. The areas where EMDR is used and the possible ways through which it is working are also described.

Menon, Sukanya B.; Jayan, C.



Fast synaptic inhibition in spinal sensory processing and pain control.  


The two amino acids GABA and glycine mediate fast inhibitory neurotransmission in different CNS areas and serve pivotal roles in the spinal sensory processing. Under healthy conditions, they limit the excitability of spinal terminals of primary sensory nerve fibers and of intrinsic dorsal horn neurons through pre- and postsynaptic mechanisms, and thereby facilitate the spatial and temporal discrimination of sensory stimuli. Removal of fast inhibition not only reduces the fidelity of normal sensory processing but also provokes symptoms very much reminiscent of pathological and chronic pain syndromes. This review summarizes our knowledge of the molecular bases of spinal inhibitory neurotransmission and its organization in dorsal horn sensory circuits. Particular emphasis is placed on the role and mechanisms of spinal inhibitory malfunction in inflammatory and neuropathic chronic pain syndromes. PMID:22298656

Zeilhofer, Hanns Ulrich; Wildner, Hendrik; Yévenes, Gonzalo E



Developmental waves of mechanosensitivity acquisition in sensory neuron subtypes during embryonic development  

PubMed Central

Somatic sensation relies on the transduction of physical stimuli into electrical signals by sensory neurons of the dorsal root ganglia. Little is known about how and when during development different types of sensory neurons acquire transduction competence. We directly investigated the emergence of electrical excitability and mechanosensitivity of embryonic and postnatal mouse sensory neurons. We show that sensory neurons acquire mechanotransduction competence coincident with peripheral target innervation. Mechanotransduction competence arises in different sensory lineages in waves, coordinated by distinct developmental mechanisms. Sensory neurons that are mechanoreceptors or proprioceptors acquire mature mechanotransduction indistinguishable from the adult already at E13. This process is independent of neurotrophin-3 and may be driven by a genetic program. In contrast, most nociceptive (pain sensing) sensory neurons acquire mechanosensitive competence as a result of exposure to target-derived nerve growth factor. The highly regulated process of mechanosensory acquisition unveiled here, reveals new strategies to identify molecules required for sensory neuron mechanotransduction.

Lechner, Stefan G; Frenzel, Henning; Wang, Rui; Lewin, Gary R



Synaptic activation of cardiac vagal neurons by capsaicin sensitive and insensitive sensory neurons  

Microsoft Academic Search

Little is known about the central circuitry involved in the sensory activation of cardioinhibitory vagal neurons (CVNs). To study the polysynaptic activation of CVNs from sensory neurons the postsynaptic currents in CVNs in the dorsal motor nucleus of the vagus (DMNX) were evoked by stimulation of the vagus nerve. In addition, the role of afferent A-fiber and C-fiber activation of

Cory Evans; Sunit Baxi; Robert Neff; Priya Venkatesan; David Mendelowitz



Hand Therapy  


... therapy provide? Preventative, Non-operative or conservative treatment Management of acute or chronic pain Desensitization following nerve injury or trauma Sensory re-education after nerve injury Design and implementation of home exercise programs to increase ...


A Comparison of Desensitization and Behavior Training With Two Teachers.  

ERIC Educational Resources Information Center

|Two elementary teachers were given systematic desensitization and behavior modification training to help them manage their feelings of anxiety and establish classroom control. Changes in teacher and student classroom behavior were recorded through daily observations by trained observers. The observers recorded teacher praise and criticism as well…

Hannum, James W.; And Others


Desensitizing Children's Emotional Reactions to the Mass Media  

Microsoft Academic Search

This experiment assesses the effectiveness of two desensitization strategies for reducing emotional reactions to mass media. Children from two grade levels (kindergarten and first vs. second through fourth grade) were assigned to one of three conditions before watching a frightening movie scene involving lizards: passive exposure to a live lizard, modeled exposure during which the experimenter touched the live lizard,




Eye Movement Desensitization and Reprocessing (EMDR): A Meta-Analysis  

Microsoft Academic Search

Eye movement desensitization and reprocessing (EMDR), a controversial treatment suggested for posttraumatic stress disorder (PTSD) and other conditions, was evaluated in a meta-analysis of 34 studies that examined EMDR with a variety of populations and measures. Process and outcome measures were examined separately, and EMDR showed an effect on both when compared with no treatment and with therapies not using

Paul R. Davidson; Kevin C. H. Parker



Eye Movement Desensitization and Reprocessing (EMDR) and the Anxiety Disorders  

Microsoft Academic Search

Four recent, independent, rigorously controlled studies of Eye Movement Desensitization and Reprocessing (EMDR) have reported that 84 to 100% of single-trauma victims no longer maintain the posttraumatic stress disorder diagnosis after the equivalent of three 90-minute sessions. The rapidity of EMDR treatment effects makes many ancillary research opportunities available. Specifically, the increased number of cases resolved in a relatively short

Francine Shapiro



Eye Movement Desensitization and Reprocessing: A Critical Analysis.  

ERIC Educational Resources Information Center

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…

Erwin, Terry McVannel


Desensitizing Children's Emotional Reactions to the Mass Media.  

ERIC Educational Resources Information Center

|Assesses effectiveness of two desensitization strategies for reducing children's emotional reactions to mass media. Examines children having passive exposure, modeled exposure, or no exposure to lizards before watching a horror movie involving lizards. Finds that modeled exposure decreases emotional reactions and negative interpretations, whereas…

Wilson, Barbara J.



Effects of group systematic desensitization on female orgasmic dysfunction  

Microsoft Academic Search

This study investigated the impact of group systematic desensitization (SD) on varied aspects of sexual functioning in primary and secondary nonorgasmic women. After serving as their own controls, 22 women (eight primary, 14 secondary) received 15 sessions of group SD using four common hierarchies of sexual scenes. The measures were administered to each subject and her regular sex partner at

Wayne M. Sotile; Peter R. Kilmann



Desensitization Mechanism in Prokaryotic Ligand-gated Ion Channel  

PubMed Central

Crystal structures of Gloeobacter violaceus ligand-gated ion channel (GLIC), a proton-gated prokaryotic homologue of pentameric ligand-gated ion channel (LGIC) from G. violaceus, have provided high-resolution models of the channel architecture and its role in selective ion conduction and drug binding. However, it is still unclear which functional states of the LGIC gating scheme these crystal structures represent. Much of this uncertainty arises from a lack of thorough understanding of the functional properties of these prokaryotic channels. To elucidate the molecular events that constitute gating, we have carried out an extensive characterization of GLIC function and dynamics in reconstituted proteoliposomes by patch clamp measurements and EPR spectroscopy. We find that GLIC channels show rapid activation upon jumps to acidic pH followed by a time-dependent loss of conductance because of desensitization. GLIC desensitization is strongly coupled to activation and is modulated by voltage, permeant ions, pore-blocking drugs, and membrane cholesterol. Many of these properties are parallel to functions observed in members of eukaryotic LGIC. Conformational changes in loop C, measured by site-directed spin labeling and EPR spectroscopy, reveal immobilization during desensitization analogous to changes in LGIC and acetylcholine binding protein. Together, our studies suggest conservation of mechanistic aspects of desensitization among LGICs of prokaryotic and eukaryotic origin.

Velisetty, Phanindra; Chakrapani, Sudha



Morphology of human intracardiac nerves: an electron microscope study  

PubMed Central

Since many human heart diseases involve both the intrinsic cardiac neurons and nerves, their detailed normal ultrastructure was examined in material from autopsy cases without cardiac complications obtained no more than 8 h after death. Many intracardiac nerves were covered by epineurium, the thickness of which was related to nerve diameter. The perineurial sheath varied from nerve to nerve and, depending on nerve diameter, contained up to 12 layers of perineurial cells. The sheaths of the intracardiac nerves therefore become progressively attenuated during their course in the heart. The intraneural capillaries of the human heart differ from those in animals in possessing an increased number of endothelial cells. A proportion of the intraneural capillaries were fenestrated. The number of unmyelinated axons within unmyelinated nerve fibres was related to nerve diameter, thin cardiac nerves possessing fewer axons. The most distinctive feature was the presence of stacks of laminated Schwann cell processes unassociated with axons that were more frequent in older subjects. Most unmyelinated and myelinated nerve fibres showed normal ultrastructure, although a number of profiles displayed a variety of different axoplasmic contents. Collectively, the data provide baseline information on the normal structure of intracardiac nerves in healthy humans which may be useful for assessing the degree of nerve damage both in autonomic and sensory neuropathies in the human heart.




Diabetic Radiculoneuropathy: Clinical patterns of sensory loss and distal paresthesias  

Microsoft Academic Search

It is the purpose of this review article to draw attention to some of the patterns of sensory abnormalities which occur in diabetic radiculoneuropathy. (The term 'radiculoneuropathy' is used in preference to the more commonly used term 'neuropathy' since, as noted below, there is considerable evidence that spinal roots, as well as peripheral nerves, are involved pathologically in diabetes mellitus:3).

Stephen G. Waxman



Chronic NGF treatment of rat nociceptive DRG neurons in culture facilitates desensitization and deactivation of GABAA receptor-mediated currents  

PubMed Central

The present study tested the hypothesis that nerve growth factor (NGF) could affect presynaptic inhibition mediated by GABAA (GABA-sensitive ionotropic receptors) receptors on the afferents of nociceptive dorsal root ganglia (DRG) neurons, thus reducing the filtering of central nociceptive signals. To investigate this issue, small-diameter, nociceptive DRG neurons were cultured for 48–72 h either in the normal medium or in the presence of NGF (50 ng ml?1). After 15 min washout, cells were patch clamped with Cs+ containing electrodes to block GABAB (GABA-sensitive metabotropic receptors) receptor-activated currents. Chronically treated DRG neurons showed no difference in the peak amplitude of GABA-induced currents. However, NGF-treated cells exhibited increased fading of the response to continuous GABA application, with faster desensitization onset, decreased residual current at the end of agonist application and slower recovery from desensitization. Moreover, the deactivation phase after brief agonist pulses was also accelerated. Unlike responses to GABA, chronic NGF treatment had no effect on the desensitization process to the excitatory transmitter ATP, as no difference in peak amplitude, fast and slow time constants of current decay was found. Experimental tests indicated that the observed effects on GABA currents were not a reactive process triggered by washing out NGF after its long application. Acutely applied NGF did not change GABAA receptor-mediated responses. NGF-treated neurons showed decreased sensitivity to the antagonist picrotoxin. The action of pentobarbitone, midazolam, bicuculline or gabazine was, however, unchanged. These observations suggest that the modulation of GABAA receptor function of DRG nociceptors by NGF may contribute to the algogenic action of this neurotrophin.

Fabbro, Alessandra; Nistri, Andrea



Ultrasound of the sural nerve: Normal anatomy on cadaveric dissection and case series.  


The sural nerve is a small sensory nerve innervating the lateral aspect of the ankle and foot. Clinical symptoms of pathology may present as atypical sensory changes in this region. We present the normal anatomy and ultrasound technique for examination of the sural nerve based on an anatomical dissection, as well as imaging in a normal volunteer. We also present a case series (n=10) of different conditions of the sural nerve that we encountered based on a review of interesting cases from 4 institutions. The pathological conditions included neuropathy related to stripping or venous laser surgery, compression by abscess, Lyme disease, nerve tumors, traumatic transsection, and encasement by fibrous plaque and edema. Ultrasound with its exquisite resolution is the preferred imaging method for examining the sural nerve in patients with unexplained sensory changes at the lateral aspect of the ankle and foot. PMID:23809918

Belsack, Dries; Jager, Tjeerd; Scafoglieri, Aldo; Vanderdood, Kurt; Van Hedent, Eddy; Vanhoenacker, Filip; Marcelis, Stefaan; De Maeseneer, Michel



Acid-sensitive vagal sensory pathways and cough  

PubMed Central

Acid is an important mediator in the pathogenesis of cough. Inhalation of exogenous acid triggers cough and endogenous acid may contribute to cough in respiratory diseases. Acid directly stimulates vagal bronchopulmonary sensory nerves that regulate the cough reflex. Consistent with their putative role in defence against aspiration and inhaled irritants, A?-fibre nociceptors in the large airways are most efficiently stimulated by rapid acidification. In contrast, acid-sensitive properties of the C-fibre nociceptors allow for continuous monitoring of pH which is likely important in inflammation. Acid is also the single most important mediator in the pathogenesis of cough due to gastro-oesophageal reflux (GOR). The cough pathways can be sensitized by the sensory inputs from the oesophagus. This sensitization is likely mediated by a subset of the vagal oesophageal sensory nerves distinguished by discriminative responsiveness to noxious stimuli (nociceptors). The receptors underlying acid-sensitivity of vagal sensory nerves are incompletely understood. The role of TRPV1 has been established but the roles of acid-sensing ion channels (ASIC) and other receptors await more definitive investigation. Here we provide a brief overview of the cough-related acid-sensitive sensory pathways and discuss the mechanisms of acid-sensitivity.

Kollarik, Marian; Ru, Fei; Undem, Bradley J.



Sensory Conversion Devices  

NASA Astrophysics Data System (ADS)

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.

Medelius, Pedro


Signaling by sensory receptors.  


Sensory systems detect small molecules, mechanical perturbations, or radiation via the activation of receptor proteins and downstream signaling cascades in specialized sensory cells. In vertebrates, the two principal categories of sensory receptors are ion channels, which mediate mechanosensation, thermosensation, and acid and salt taste; and G-protein-coupled receptors (GPCRs), which mediate vision, olfaction, and sweet, bitter, and umami tastes. GPCR-based signaling in rods and cones illustrates the fundamental principles of rapid activation and inactivation, signal amplification, and gain control. Channel-based sensory systems illustrate the integration of diverse modulatory signals at the receptor, as seen in the thermosensory/pain system, and the rapid response kinetics that are possible with direct mechanical gating of a channel. Comparisons of sensory receptor gene sequences reveal numerous examples in which gene duplication and sequence divergence have created novel sensory specificities. This is the evolutionary basis for the observed diversity in temperature- and ligand-dependent gating among thermosensory channels, spectral tuning among visual pigments, and odorant binding among olfactory receptors. The coding of complex external stimuli by a limited number of sensory receptor types has led to the evolution of modality-specific and species-specific patterns of retention or loss of sensory information, a filtering operation that selectively emphasizes features in the stimulus that enhance survival in a particular ecological niche. The many specialized anatomic structures, such as the eye and ear, that house primary sensory neurons further enhance the detection of relevant stimuli. PMID:22110046

Julius, David; Nathans, Jeremy



Nerve Racking  

NSDL National Science Digital Library

This lesson describes the function and components of the human nervous system. It helps students understand the purpose of our brain, spinal cord, nerves and the five senses. How the nervous system is affected during spaceflight is also discussed in this lesson.

Integrated Teaching And Learning Program


Assessing decreased sensation and increased sensory phenomena in diabetic polyneuropathies.  


Loss of sensation and increased sensory phenomena are major expressions of varieties of diabetic polyneuropathies needing improved assessments for clinical and research purposes. We provide a neurobiological explanation for the apparent paradox between decreased sensation and increased sensory phenomena. Strongly endorsed is the use of the 10-g monofilaments for screening of feet to detect sensation loss, with the goal of improving diabetic management and prevention of foot ulcers and neurogenic arthropathy. We describe improved methods to assess for the kind, severity, and distribution of both large- and small-fiber sensory loss and which approaches and techniques may be useful for conducting therapeutic trials. The abnormality of attributes of nerve conduction may be used to validate the dysfunction of large sensory fibers. The abnormality of epidermal nerve fibers/1 mm may be used as a surrogate measure of small-fiber sensory loss but appear not to correlate closely with severity of pain. Increased sensory phenomena are recognized by the characteristic words patients use to describe them and by the severity and persistence of these symptoms. Tests of tactile and thermal hyperalgesia are additional markers of neural hyperactivity that are useful for diagnosis and disease management. PMID:24158999

Dyck, Peter J; Herrmann, David N; Staff, Nathan P; Dyck, P James B



Protein kinase C modulation of cardiomyocyte angiotensin II and vasopressin receptor desensitization.  


Angiotensin II (Ang II) and arginine vasopressin (AVP) increased intracellular free Ca2+ concentration [Ca2+]i and/or the [Ca2+]i transient rate (CaTR) in cultured neonatal rat cardiomyocytes. These agents increased membrane-bound protein kinase C (PKC) with peak activity at 5 and 10 minutes, respectively. Two-minute exposure to Ang II produced homologous desensitization to a repeated stimulation with Ang II and heterologous desensitization to AVP. Two-minute exposure to AVP also produced homologous desensitization to AVP but not heterologous desensitization to Ang II. When the AVP exposure time was increased from 2 to 10 minutes coincident with maximal AVP-mediated PKC activation, heterologous desensitization to Ang II was also observed. Acute activation (15 minutes) of PKC by phorbol 12-myristate 13-acetate (PMA) blocked responsiveness to both Ang II and AVP. When PKC activation was inhibited by 20 hours of prior exposure to PMA, as confirmed by PKC assay, homologous desensitization of Ang II still occurred, confirming an alternative mechanism(s) for homologous desensitization in the cardiomyocytes. In contrast, 20-hour PMA suppression of PKC markedly diminished the ability of the cardiomyocytes to exhibit AVP-mediated heterologous desensitization for Ang II. These data indicate that PKC activation plays a primary role in mediating vasopressin V1 receptor-induced heterologous desensitization of the Ang II receptor and participates in a hierarchy of two or more kinase systems mediating homologous desensitization of the Ang II receptor in cardiomyocytes. PMID:8567051

Zhang, M; Turnbaugh, D; Cofie, D; Dogan, S; Koshida, H; Fugate, R; Kem, D C



A novel internal fixator device for peripheral nerve regeneration.  


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

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



Sensory Correlations in Autism  

ERIC Educational Resources Information Center

|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…

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.



Sensory Correlations in Autism  

ERIC Educational Resources Information Center

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…

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.



Sensory correlations in autism  

Microsoft Academic Search

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 processing modalities using total scores. Analysis also showed

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



Expression of leukemia inhibitory factor in human nerve following injury.  


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

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



Peripheral nerve regeneration through optic nerve grafts  

Microsoft Academic Search

Grafts of optic nerve were placed end-toend with the proximal stumps of severed common peroneal nerves in inbred mice. It was found that fraying the proximal end of adult optic nerve grafts to disrupt the glia limitans increased their chances of being penetrated by regenerating peripheral nerve fibres. Suturing grafts to the proximal stump also enhanced their penetration by axons.

P. N. Anderson; P. Woodham; M. Turmaine



Cutaneous Indentation Sensory Testing Device.  

National Technical Information Service (NTIS)

In one embodiment, the present invention provides a sensory testing system. In another embodiment, the present invention provides a method of using a sensory testing system to determine sensory pressure thresholds. In a further embodiment, the present inv...

D. R. Robichaud G. M. Bove M. Cannella P. Grigg




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...


Peripheral nerve conduction in Miller Fisher syndrome.  

PubMed Central

Two cases of acute ophthalmoplegia, ataxia, and arreflexia with high CSF protein are reported (Miller Fisher syndrome). Detailed EMG and nerve conduction studies showed abnormal conduction in peripheral sensory fibres from the initial stages of the illness in both patients. Careful review up to 10 months after the onset was required to document the sensory conduction abnormality properly in one of them. The electrical findings did not differ from those that can be seen in the Guillain-Barré syndrome and provided no clues as to the mechanism of the ataxia.

Guiloff, R J



Neurology: an ancient sensory organ in crocodilians.  


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

Soares, Daphne



Ultrasound vs nerve stimulation multiple injection technique for posterior popliteal sciatic nerve block.  


In this prospective, randomised, observer-blinded study we evaluated whether ultrasound guidance can shorten the onset time of popliteal sciatic nerve block as compared to nerve stimulation with a multiple injection technique. Forty-four ASA I-III patients undergoing posterior popliteal sciatic nerve block with 20 ml of 0.75% ropivacaine were randomly allocated to nerve stimulation or ultrasound guided nerve block. A blinded observer recorded onset of sensory and motor blocks, success rates, the need for fentanyl intra-operatively, the requirement for general anaesthesia, procedure-related pain, patient satisfaction and side-effects. Onset times for sensory and motor blocks were comparable. The success rate was 100% for ultrasound guided vs 82% for nerve stimulation (p = 0.116). Ultrasound guidance reduced needle redirections (p = 0.01), were associated with less procedural pain (p = 0.002) and required less time to perform (p = 0.002). Ultrasound guidance reduced the time needed for block performance and procedural pain. PMID:19453318

Danelli, G; Fanelli, A; Ghisi, D; Moschini, E; Rossi, M; Ortu, A; Baciarello, M; Fanelli, G



Maxillary nerve compression in cynomolgus monkey Macaca fascicularis: altered somatic sensation and peripheral nerve firing  

PubMed Central

Background Trigeminal nerve is a major source of the sensory input of the face, and trigeminal neuropathology models have been reported in rodents with injury to branches of the maxillary or mandibular division of the trigeminal nerve. Non-human primates are neuroanatomically more closely related to human than rodents; however, nerve injury studies in non-human primates are limited. Results We describe here a nerve injury model of maxillary nerve compression (MNC) in the cynomolgus macaque monkey, Macaca fascicularis, and the initial characterization of the consequences of damage to this trigeminal nerve branch. The nerve injury from the compression appeared to be mild, as we did not observe overt changes in home-cage behavior in the monkeys. When mechanical stimulation was applied to the facial area, monkeys with MNC displayed increased mechanical sensitivity, as the avoidance response scores were lower than those from the control animals. Such a change in mechanical sensitivity appeared to be somewhat bilateral, as the contralateral side also showed increased mechanical sensitivity, although the change on the ipsilateral side was more robust. Multiple-unit recording of the maxillary nerve showed a general pattern of increasing responsiveness to escalating force in mechanical stimulation on the contralateral side. Ipsilateral side of the maxillary nerve showed a lack of responsiveness to escalating force in mechanical stimulation, possibly reflecting a maximum stimulation threshold effect from sensitized nerve due to MNC injury. Conclusions These results suggest that MNC may produce increased sensitivity of the ipsilateral maxillary nerve, and that this model may serve as a non-human primate model to evaluate the effect of injury to trigeminal nerve branches.



Polymerization of actin does not regulate desensitization in human basophils  

Microsoft Academic Search

Previous studies have suggested that maintenance of IgE-mediated signaling results from regulation of the activity of signaling com- plexes by actin polymerization. This process is also hypothesized to be related to desensitization of basophils and mast cells. Recent studies demon- strated that any signaling process dependent on syk or PI-3K activity cannot be a mechanism of desen- sitization, and in

Donald MacGlashan Jr; Natalia Vilarino



Playing violent video games, desensitization, and moral evaluation in children  

Microsoft Academic Search

Relationships between short- and long-term exposure to violent video games and desensitization, as measured through components of moral evaluation, were examined. Sixty-six children aged 5–12 years old completed questionnaires assessing video game experience and preferences and empathy and attitudes toward violence. The children played a violent or nonviolent video game and then responded to vignettes about everyday occurrences. Vignette responses

Jeanne B. Funk; Debra D. Buchman; Jennifer Jenks; Heidi Bechtoldt



Eye movement desensitization and reprocessing (EMDR): An overview  

Microsoft Academic Search

Eye movement desensitization and reprocessing (EMDR) is a recently developed psychotherapy procedure which has been reported\\u000a to dramatically increase efficiency in the treatment of psychological disturbances rooted in traumatic memories. Following\\u000a a review of the research on EMDR's efficacy, clinical considerations are addressed, including the client's experience and\\u000a the potential for negative effects or treatment failure. Finally, the role of

Ricky Greenwald



Clinical anatomy of the lingual nerve and identification with ultrasonography.  


Our objective was to investigate the pathway of the lingual nerve and find out whether it can be identified using ultrasonography (US) intraorally. It is a dominant sensory nerve that branches from the posterior division of the mandibular aspect of the trigeminal nerve, and is one of the two most injured nerves during oral surgery. Its anatomy in the region of the third molar has been associated with lingual nerves of variable morphology. If surgeons can identify its precise location using US, morbidity should decrease. We searched published anatomical and specialty texts, journals, and websites for reference to its site and US. Cadavers (28 nerves) were dissected to analyse its orientation at the superior lingual alveolar crest (or lingual shelf). Volunteers (140 nerves) had US scans to identify the nerve intraorally. Our search of published books and journals found that descriptions of the nerve along the superior lingual alveolar crest were inadequate. We found no US studies of the nerve in humans. Dissections showed that the nerve was above (n=6, 21%) and below (n=22, 79%) the crest of the lingual plate. US scans showed 140 lingual nerves intraorally in 70 volunteers. The nerve lay either above or below the superior lingual alveolar crest, which led us to develop a high/low classification system. US can identify the lingual nerve and help to classify it preoperatively to avoid injury. Our results suggest that clinical anatomy of the lingual nerve includes the superior lingual alveolar crest at the third and second molars because of its surgical importance. US scans can successfully identify the nerve intraorally preoperatively. PMID:23182453

Benninger, Brion; Kloenne, Jessica; Horn, Jean Lois



Relationship between the G protein signaling and homologous desensitization of G protein-coupled receptors  

Microsoft Academic Search

Signaling and desensitization of G protein-coupled receptor are intimately related, and measuring them separately requires certain parameters that represent desensitization independently of signaling. In this study, we tested whether desensitization requires signaling in three different receptors, ?2-adrenergic receptor (?2AR) in S49 lymphoma cells, ?-factor pheromone receptor (Ste2p) in Saccharomyces cerevisiae LM102 cells, and dopamine D3 receptor (D3R) in HEK-293 cells.

Larry S. Barak; Jacqueline Gilchrist; Jeffrey M. Becker; Kyeong-Man Kim



Desensitization onset and recovery at the potassium-depolarized frog neuromuscular junction are voltage sensitive  

Microsoft Academic Search

A B S T R A C T The influence of voltage on the time-course of desensitization onset and recovery has been studied at the frog neuromuscular junction. The activation- desensitization sequence was determined from carbachol-induced end-plate cur- rents in potassium-depolarized fibers voltage-clamped either to -40 mV or +40 mV. The time-course of both desensitization onset and recovery developed exponentially,




Shock desensitization of PBX-9404 and Composition B-3  

SciTech Connect

PBX-9404 and Composition B-3 were desensitized by subjecting them to shocks in the pressure range 10 to 24 kbar. Results show that the collapse of voids, and thus the activation of hot spots by shock waves, takes time and may require more than 5 This time is, in a way, a counterpart of the induction time for shock initiation of a homogeneous explosive. Gittings' data are adduced to extend the results to 100 kbar and to show that at high pressures desensitization occurs in a very brief time window. When the voids have been collapsed, the relatively homogeneous explosive is resistant to detonation through an Arrhenius type of reaction because of the lower shock temperature resulting from double shocking. This conclusion is supported by experiments on single crystals of HMX and by shock temperature calculations. The time required for desensitization of PBX-9404 is related to pressure by the expression p/sup 2.2/tau = 1150. 21 references, 5 figures, 5 tables.

Campbell, A.W.; Travis, J.R.



Effects of desensitizing agents on dentinal tubule occlusion.  


The aim of this study was to evaluate the features of dentinal tubules occlusion following application of three commercially available desensitizing agents: potassium oxalate-based / Oxa-Gel (OX), HEMA and glutaraldehyde-based / Gluma Desensitizer (GD) and acidulated phosphate fluoride-based / Nupro Gel (AF). Buccal cervical areas of twenty-four extracted human third molars were smoothed and wet-polished with SiC papers and diamond pastes, in order to simulate the clinical aspect of hypersensitive dentin cervical surfaces. The teeth were randomly divided into four groups (n=6), according to the dentin surface treatments: G1: untreated; G2: OX; G3: GD; G4: AF. Specimens were fractured in the lingual-buccal direction and prepared for SEM analysis. OX promoted tubule occlusion by crystal-like deposits in the lumen of the tubules. While GL created a thin layer over the dentin surface, AF application produced precipitates that occluded the tubules. According to the SEM analysis, all desensitizing agents were able to occlude the dentinal tubules. PMID:21365138

Arrais, César Augusto Galvăo; Chan, Daniel Chi Ngai; Giannini, Marcelo



Sensory Characteristics in ASD  

PubMed Central

In this paper, we review evidence regarding differences in the types of sensory experiences of persons with ASD with respect to both unisensory and multisensory processing. We discuss selfreports, carer questionnaires as well as perceptual processing differences found in the laboratory. Incoming information is processed through one or more of our senses and fundamental differences in the processing of information from any sensory modality or combination of sensory modalities are likely to have cascading effects on the way individuals with ASD experience the world around them, effects that can have both positive and negative impact on a individual with ASD’s quality of life.

Stewart, Mary E.; Russo, Natalie; Banks, Jennifer; Miller, Louisa; Burack, Jacob A.



Short-term restoration of facial sensory loss by motor cortex stimulation in peripheral post-traumatic neuropathic pain  

Microsoft Academic Search

We report a case in which motor cortex stimulation (MCS) improved neuropathic facial pain due to peripheral nerve injury and\\u000a restored tactile and thermal sensory loss. A 66-year-old man developed intractable trigeminal neuropathic pain after trauma\\u000a of the supraorbital branch of the Vth nerve, associated with tactile and thermal sensory loss in the painful area. MCS was\\u000a performed using neuronavigation

Denys Fontaine; Jean Louis Bruneto; Hasna El Fakir; Philippe Paquis; Michel Lanteri-Minet



Increased Numbers of Thoracic Dorsal Root Axons in Rats Given Antibodies to Nerve Growth Factor  

NASA Astrophysics Data System (ADS)

Sensory axons were counted in untreated 1-month-old rats and in littermates that were injected with antibodies to nerve growth factor. There were 45 percent more unmyelinated and 17 percent more myelinated axons in dorsal roots of the fifth thoracic spinal segment in treated rats. This suggests that the number of sensory axons can be changed by postnatal inactivation of nerve growth factor.

Hulsebosch, C. E.; Coggeshall, R. E.; Perez-Polo, J. R.



Considerations in nerve repair  

Microsoft Academic Search

ome nerve injuries require repair in order to regain sen- sory or motor function. Although this article focuses pri- marily on trigeminal nerve (TN) injuries and repairs, the facts presented may apply to any peripheral nerve repair. The primary indications for nerve repair or grafting are 1) an injury or continuity defect in a nerve, as a result of trauma,



Multiphasic desensitization of the GABAA receptor in outside-out patches.  

PubMed Central

GABAA receptor function was studied in outside-out patches from guinea pig hippocampal neurons using a drug application system with an exchange time of under 1.5 ms. Application of GABA to these patches induced a Cl- conductance that desensitized with prolonged exposure. Increasing GABA concentrations induced larger conductance increases that were associated with more complex patterns of desensitization. Smaller GABA responses desensitized with monophasic kinetics, whereas large responses displayed bi- and triphasic kinetics. Desensitization of the response to 1 mM GABA was triphasic in about 70% of the patches (tau = 15.4, 207, and 1370 ms) and biphasic in about 30% of the patches (tau = 44 and 725 ms). All phases of desensitization reversed at the Cl- equilibrium potential. Over the concentration range from 3 microM to 3 mM, both the rate and the extent of desensitization increased; however, complete desensitization was rarely observed. The increase in desensitization rate was due to an increase in the relative contribution of the faster phases with increasing GABA. The time constants of the three phases were independent of concentration. The different phases are not mediated by separate receptor populations, because double pulse experiments demonstrated interconversion among the fastest phase and the two slower phases. We demonstrate the plausibility of a model in which multiphasic desensitization is a consequence of the faster association rate at higher GABA concentrations.

Celentano, J J; Wong, R K



Multiple components of ganglion cell desensitization in response to prosthetic stimulation  

NASA Astrophysics Data System (ADS)

Retinal prostheses aim to restore functional vision to those blinded by outer retinal diseases using electric stimulation of surviving neurons. Previous work indicates that repetitive stimulation with stimuli that activate the synaptic network reduces the sensitivity of retinal neurons to further stimulation. Such desensitization may contribute to the fading of visual percepts over time reported by human subjects. Here, we show that desensitization may be more complex than previously considered. We recorded spike trains from rabbit retinal ganglion cells and found that desensitization persists in the presence of inhibitory blockers (strychnine and picrotoxin), indicating amacrine cell inhibition is not solely responsible for reducing sensitivity in response to electric stimulation. The threshold for direct activation of the ganglion cell changes little during the simultaneous desensitization of the synaptically mediated response, indicating that desensitization likely occurs upstream of the spike generator. In addition to rapid desensitization acting over hundreds of milliseconds (? = 176.4 ± 8.8 ms), we report the presence of slow acting desensitization with a time course of seconds (? = 14.0 ± 1.1 s). The time courses of the two components of desensitization that we found are similar to the two phases of brightness fading seen in human subjects. This suggests that the reduction in ganglion cell firing due to desensitization may be responsible for the fading of visual percepts over time in response to prosthetic stimulation.

Freeman, Daniel K.; Fried, Shelley I.



[Peripheral nerve disorders--clinical pathological approaches].  


Clinical pathological approach is defined as combination of neurological, neurophysiological and neuroradiological findings for the interpretation of the morphology of the sural nerve. For this purpose, first, the usefulness of simultaneous biopsy of sural nerve and ipsilateral short peroneal muscle was presented. This method has helped establish the diagnosis of angitis or amyloidosis in some cases. Furthermore, motor-dominant clinical picture was ascertained by relative preservation of sural nerve in contrast with severe changes in intramuscular nerve fascicles. Second, histochemistry using UEA-1 lectin to detect somatic sensory C fibers was discussed. UEA-1 specifically binds to unmyelinated axons and small neurons in dorsal root ganglia as well as substantia gelatinosa of the spinal cord. Serial semithin and ultrathin sections were obtained. The semithin section was removed of epon and stained histochemically with UEA-1. Positive fibers in the semithin section was compared with the counterpart in the ultrathin sections. UEA-1 positive fibers were found to comprise 20% of all unmyelinated fibers and be randomly distributed among the entire nerve fascicles. The application of this technique to pathological specimens is now undergoing. Third, an autopsy case with sarin intoxication was reported as an example of systemic study of the peripheral nervous system. The patient was a 51-year-old man who inhaled sarin in the attack of Tokyo Subway. He fell into vegetative state and was passively maintained for 13 months. Peripheral sensory nerve showed typical pattern of dying back-type distal peripheral axonopathy. It might be indicated that peripheral nerve be carefully checked among the sarin victims. In conclusion, the aim of our approach is to combine all clinical information, introduce recent advance in neuroscience, and try to find possible cure to intractable neurological disorders. PMID:9577657

Murayama, S



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


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) PMID:1356654

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



Neuromorphic sensory systems.  


Biology provides examples of efficient machines which greatly outperform conventional technology. Designers in neuromorphic engineering aim to construct electronic systems with the same efficient style of computation. This task requires a melding of novel engineering principles with knowledge gleaned from neuroscience. We discuss recent progress in realizing neuromorphic sensory systems which mimic the biological retina and cochlea, and subsequent sensor processing. The main trends are the increasing number of sensors and sensory systems that communicate through asynchronous digital signals analogous to neural spikes; the improved performance and usability of these sensors; and novel sensory processing methods which capitalize on the timing of spikes from these sensors. Experiments using these sensors can impact how we think the brain processes sensory information. PMID:20493680

Liu, Shih-Chii; Delbruck, Tobi



Spinal Cord and Nerve Root Decompression  

Microsoft Academic Search

Tumors of the vertebral column include both primary and metastatic lesions. These tumors can cause significant morbidity consisting\\u000a of lesional pain and pain from deformity. Compression of the spinal cord and spinal nerve roots can also cause radicular pain\\u000a as well as neurologial deterioration including sensory deficits, weakness, paralysis, and\\/or sexual\\/bowel\\/ bladder dysfunction.\\u000a In cases of metastatic lesions, the spine

Keith R. Lodhia; Paul Park; Gregory P. Graziano


Early interfaced neural activity from chronic amputated nerves.  


Direct interfacing of transected peripheral nerves with advanced robotic prosthetic devices has been proposed as a strategy for achieving natural motor control and sensory perception of such bionic substitutes, thus fully functionally replacing missing limbs in amputees. Multi-electrode arrays placed in the brain and peripheral nerves have been used successfully to convey neural control of prosthetic devices to the user. However, reactive gliosis, micro hemorrhages, axonopathy and excessive inflammation currently limit their long-term use. Here we demonstrate that enticement of peripheral nerve regeneration through a non-obstructive multi-electrode array, after either acute or chronic nerve amputation, offers a viable alternative to obtain early neural recordings and to enhance long-term interfacing of nerve activity. Non-restrictive electrode arrays placed in the path of regenerating nerve fibers allowed the recording of action potentials as early as 8 days post-implantation with high signal-to-noise ratio, as long as 3 months in some animals, and with minimal inflammation at the nerve tissue-metal electrode interface. Our findings suggest that regenerative multi-electrode arrays of open design allow early and stable interfacing of neural activity from amputated peripheral nerves and might contribute towards conveying full neural control and sensory feedback to users of robotic prosthetic devices. PMID:19506704

Garde, Kshitija; Keefer, Edward; Botterman, Barry; Galvan, Pedro; Romero, Mario I



Nerve conduction velocity  


Nerve conduction velocity (NCV) is a test to see how fast electrical signals move through a nerve. ... travel between electrodes are used to determine the speed of the nerve signals. Electromyography (recording from needles ...


Primary sensory neuronal rescue with systemic acetyl- l-carnitine following peripheral axotomy. A dose-response analysis  

Microsoft Academic Search

The loss of a large proportion of primary sensory neurons after peripheral nerve axotomy is well documented. As a consequence of this loss, the innervation density attained on completion of regeneration will never be normal, regardless of how well the individual surviving neurons regenerate. Acetyl-l-carnitine (ALCAR), an endogenous peptide in man, has been demonstrated to protect sensory neurons, thereby avoiding

Andrew D. H Wilson; Andrew Hart; Thomas Brannstrom; Mikael Wiberg; Giorgio Terenghi



Sox11 transcription factor modulates peripheral nerve regeneration in adult mice  

Microsoft Academic Search

The ability of adult peripheral sensory neurons to undergo functional and anatomical recovery following nerve injury is due in part to successful activation of transcriptional regulatory pathways. Previous in vitro evidence had suggested that the transcription factor Sox11, a HMG-domain containing protein that is highly expressed in developing sensory neurons, is an important component of this regenerative transcriptional control program.

Michael P. Jankowski; Sabrina L. McIlwrath; Xiaotang Jing; Pamela K. Cornuet; Kathleen M. Salerno; H. Richard Koerber; Kathryn M. Albers



Nerve function in galactosaemic rats: effects of evening primrose oil and doxazosin  

Microsoft Academic Search

Rats were fed for 6 weeks with a 40% galactose diet to chronically stimulate the polyol pathway. Sciatic motor and saphenous sensory nerve conduction velocity deficits of 22% and 14% respectively developed. Treatment with evening primrose oil or doxazosin from galactosaemia induction partially (approximately 60%) prevented the development of reduced motor and sensory conduction, the former treatment being more successful

Kevin C. Dines; Mary A. Cotter; Norman E. Cameron



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

SciTech Connect

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.

Galant, S.P.; Britt, S.



Recovery from Mu-opioid Receptor Desensitization following Chronic Treatment with Morphine and Methadone  

PubMed Central

Chronic treatment with morphine results in a decrease in mu-opioid receptor sensitivity, an increase in acute desensitization and a reduction in the recovery from acute desensitization in locus coeruleus neurons. With acute administration, morphine is unlike many other opioid agonists in that it does not mediate robust acute desensitization or induce receptor trafficking. This study compares mu-opioid receptor desensitization and trafficking in brain slices taken from rats treated for 6–7 days with a range of doses of morphine (60, 30, 15 mg/kg/day) and methadone (60, 30, 5 mg/kg/day) applied by subcutaneous implantation of osmotic mini pumps. Mice were treated with 45 mg/kg/day. In morphine treated animals, recovery from acute [Met]5enkephalin-induced desensitization and receptor recycling was diminished. In contrast, recovery and recycling were unchanged in slices from methadone treated animals. Remarkably the reduced recovery from desensitization and receptor recycling found in slices from morphine treated animals were not observed in animals lacking ?-arrestin2. Further, pharmacological inhibition of GRK2, while not affecting the ability of [Met]5enkephalin to induce desensitization, acutely reversed the delay in recovery from desensitization produced by chronic morphine treatment. These results characterize a previously unidentified function of the GRK/arrestin system in mediating opioid regulation in response to chronic morphine administration. They also suggest that the GRK/arrestin system, rather then serving as a primary mediator of acute desensitization, controls recovery from desensitization by regulating receptor reinsertion to the plasma membrane after chronic treatment with morphine. The sustained GRK/arrestin dependent desensitization is another way in which morphine and methadone are distinguished.

Quillinan, Nidia; Lau, Elaine; Virk, Michael; von Zastrow, Mark; Williams, John T



Nerve Impulses in Plants  

ERIC Educational Resources Information Center

|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)|

Blatt, F. J.



Nerve Impulses in Plants  

ERIC Educational Resources Information Center

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)

Blatt, F. J.



Examining sensory quadrants in autism  

Microsoft Academic Search

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 controls. Sensory quadrants (Low

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



A case of hereditary sensory autonomic neuropathy type IV  

PubMed Central

Hereditary sensory autonomic neuropathy type IV (HSAN -IV), also known as congenital insensitivity to pain with anhidrosis, is a very rare condition that presents in infancy with anhidrosis, absence of pain sensation and self -mutilation. Developmental delay and mental retardation are usually present. Ultrastructural study of the peripheral nerves demonstrates loss of the unmyelinated and small myelinated fibers. We here report a 8 year -old boy with HSAN IV with typical clinical features where the diagnosis was supported by nerve biopsy findings. However, our case was unusual since mental development was normal.

Prashanth, G. P.; Kamate, Mahesh



Electrophysiological findings in entrapment of the median nerve at wrist and elbow  

Microsoft Academic Search

In 117 consecutive patients with carpal tunnel syndrome and 11 patients with a compression syndrome of the median nerve at elbow, motor and sensory conduction along the median and ulnar nerves and quantitative electromyography were compared with findings in 190 normal controls of the same age. In 25% of patients with carpal tunnel syndrome in whom motor conduction and EMG

Fritz Buchthal; Annelise Rosenfalck; Werner Trojaborg



Do nerve growth factor-related mechanisms contribute to loss of cutaneous nociception in leprosy?  

Microsoft Academic Search

While sensory loss in leprosy skin is the consequence of invasion by M. leprae of Schwann cells related to unmyelinated fibres, early loss of cutaneous pain sensation, even in the presence of nerve fibres and inflammation, is a hallmark of leprosy, and requires explanation. In normal skin, nerve growth factor (NGF) is produced by basal keratinocytes, and acts via its

Paul Facer; Dawn Mann; Rajeev Mathur; Shubha Pandya; Uma Ladiwala; Bhim Singhal; Jo-Anne Hongo; Dominick V Sinicropi; Giorgio Terenghi; Praveen Anand



Electrospun micro- and nanofiber tubes for functional nervous regeneration in sciatic nerve transections  

Microsoft Academic Search

BACKGROUND: Although many nerve prostheses have been proposed in recent years, in the case of consistent loss of nervous tissue peripheral nerve injury is still a traumatic pathology that may impair patient's movements by interrupting his motor-sensory pathways. In the last few decades tissue engineering has opened the door to new approaches;: however most of them make use of rigid

Silvia Panseri; Carla Cunha; Joseph Lowery; Ubaldo Del Carro; Francesca Taraballi; Stefano Amadio; Angelo Vescovi; Fabrizio Gelain



Electrophysiological study in the infraorbital nerve of the rat: Spontaneous and evoked activity  

Microsoft Academic Search

In this work we present some studies in the afferent nerve of the rat vibrissae. Studies on spontaneous activity (SA) in this sensorial system are of long data. Nevertheless, SA recordings in the nerve of a single vibrissa have not been made until present. In this work, we use an algorithm based on signal decomposition with Continuous Wavelet Transform (CWT)

C J Felice



A Nerve Growth Factor-Induced Gene Encodes a Possible Transcriptional Regulatory Factor  

Microsoft Academic Search

Nerve growth factor (NGF) is a trophic agent that promotes the outgrowth of nerve fibers from sympathetic and sensory ganglia. The neuronal differentiation stimulated by this hormone was examined in the NGF-responsive cell line PC12. Differential hybridization was used to screen a complementary DNA library constructed from PC12 cells treated with NGF and cycloheximide. One of the complementary DNA clones

Jeffrey Milbrandt



Microneurographic findings in diabetic polyneuropathy with special reference to sympathetic nerve activity  

Microsoft Academic Search

Summary  Microneurographic recordings of naturally occurring nerve activity in the median or peroneal nerve were made in 25 patients with diabetes mellitus, 17 of whom had signs of polyneuropathy. In patients without polyneuropathy, the electrical findings did not differ from those in healthy subjects. In patients with polyneuropathy, sensory afferent impulses were always normal qualitatively, whereas muscular afferent activity was weak

J. Fagius



Hematopoietic colony-stimulating factors mediate tumor-nerve interactions and bone cancer pain.  


Pain is one of the most severe and debilitating symptoms associated with several forms of cancer. Various types of carcinomas and sarcomas metastasize to skeletal bones and cause spontaneous bone pain and hyperalgesia, which is accompanied by bone degradation and remodeling of peripheral nerves. Despite recent advances, the molecular mechanisms underlying the development and maintenance of cancer-evoked pain are not well understood. Several types of non-hematopoietic tumors secrete hematopoietic colony-stimulating factors that act on myeloid cells and tumor cells. Here we report that receptors and signaling mediators of granulocyte- and granulocyte-macrophage colony-stimulating factors (G-CSF and GM-CSF) are also functionally expressed on sensory nerves. GM-CSF sensitized nerves to mechanical stimuli in vitro and in vivo, potentiated CGRP release and caused sprouting of sensory nerve endings in the skin. Interruption of G-CSF and GM-CSF signaling in vivo led to reduced tumor growth and nerve remodeling, and abrogated bone cancer pain. The key significance of GM-CSF signaling in sensory neurons was revealed by an attenuation of tumor-evoked pain following a sensory nerve-specific knockdown of GM-CSF receptors. These results show that G-CSF and GM-CSF are important in tumor-nerve interactions and suggest that their receptors on primary afferent nerve fibers constitute potential therapeutic targets in cancer pain. PMID:19525966

Schweizerhof, Matthias; Stösser, Sebastian; Kurejova, Martina; Njoo, Christian; Gangadharan, Vijayan; Agarwal, Nitin; Schmelz, Martin; Bali, Kiran Kumar; Michalski, Christoph W; Brugger, Stefan; Dickenson, Anthony; Simone, Donald A; Kuner, Rohini



Early diagnosis of diabetic neuropathy using double-shock stimulation of peripheral nerves  

Microsoft Academic Search

Objective: The purpose of this study was to determine the changes in the amplitudes of a sensory nerve action potential (NAP) to a conditioning stimulus given prior to a test stimulus at 2–8 ms intervals in healthy subjects and patients with diabetes mellitus with no clinical signs of neuropathy and normal nerve conduction velocities (NCVs), to be able to diagnose

Meliha Tan; Uner Tan



Three ulnar nerve conduction studies in patients with ulnar neuropathy at the elbow  

Microsoft Academic Search

Objective: Ulnar neuropathy at the elbow is often difficult to localize by standard electrophysiologic testing. This study compared three ulnar nerve conduction studies to determine which was more sensitive in localizing ulnar neuropathy at the elbow.Methods: Motor studies to the first dorsal interosseous and the abductor digiti quinti and a mixed ulnar nerve sensory study across the elbow.Results: Motor studies

Milind J. Kothari; Michele Heistand; Seward B. Rutkove



Myelination changes in the rat optic nerve after prenatal exposure to methamphetamine  

Microsoft Academic Search

The use of psychostimulants during adolescence and early adult life has increased in recent years. It is known that these substances affect the sensory systems, and the optic nerve has been shown to be a target tissue. This work was conducted to evaluate the effects of prenatal exposure to methamphetamine (MA) on the developmental pattern of the rat optic nerve.

Pedro Melo; Vicente Zanón Moreno; Sheila Pons Vázquez; Maria Dolores Pinazo-Durán; Maria Amélia Tavares



Sensory Properties of Citric Acid: Psychophysical Evidence for Sensitization, Self-desensitization, Cross-desensitization and Cross-stimulus-induced Recovery Following Capsaicin  

Microsoft Academic Search

In a first experiment, human subjects used a bipolar scale to rate the irritant sensation elicited by 10 sequentially repeated applications of either 3 ppm capsaicin or 250 mM citric acid on one side of the dorsal surface of the tongue, at 1 min intervals (30 s inter-stimulus interval). Citric acid-evoked irritation significantly increased across trials, consistent with sensitization. With

J.-M. Dessirier; M. O'Mahony; M. Iodi-Carstens; E. Carstens



Non-invasive stimulation of the vibrissal pad improves recovery of whisking function after simultaneous lesion of the facial and infraorbital nerves in rats  

Microsoft Academic Search

We have recently shown that manual stimulation of target muscles promotes functional recovery after transection and surgical\\u000a repair to pure motor nerves (facial: whisking and blink reflex; hypoglossal: tongue position). However, following facial nerve\\u000a repair, manual stimulation is detrimental if sensory afferent input is eliminated by, e.g., infraorbital nerve extirpation.\\u000a To further understand the interplay between sensory input and motor

H. Bendella; S. P. Pavlov; M. Grosheva; A. Irintchev; S. K. Angelova; D. Merkel; N. Sinis; K. Kaidoglou; E. Skouras; S. A. Dunlop; Doychin N. Angelov



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

ERIC Educational Resources Information Center

|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)|

Suarez, Yolanda; And Others



Effectiveness of study counseling and desensitization in alleviating test anxiety in college students  

Microsoft Academic Search

Selected 36 male and 39 female test-anxious undergraduates. 50 Ss were assigned randomly to 1 of 2 therapists for (a) desensitization alone, (b) study counseling alone, (c) a combination of study counseling and desensitization, and (d) a placebo procedure. 25 Ss were assigned to 2 control groups. The experimental design was a repeated-measures paradigm involving pre- and posttreatment assessment of

George J. Allen



Effect of dentin desensitizers and cementing agents on retention of full crowns using standardized crown preparations  

Microsoft Academic Search

Statement of problem. Past research has not controlled preparation surface area when examining the influence of dentin desensitizers on the retentive strength of cemented cast crowns, leading to inconsistent results. Purpose. This research controlled crown preparation surface area and evaluated the effect of various dentin desensitizers and conventional cementing agents on the in vitro retentive strength of cast crowns. Methods

Nantiya H. Yim; Frederick A. Rueggeberg; W. Frank Caughman; F. Michael Gardner; David H. Pashley



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

ERIC Educational Resources Information Center

|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…

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



Applying eye movement desensitization and reprocessing (EMDR) to the treatment of traumatized children: Five case studies  

Microsoft Academic Search

Citation: Greenwald, R. (1994). Applying eye movement desensitization and reprocessing (EMDR) to the treatment of traumatized children: Fi ve case studies. Anxiety Disorders Practice Journal, 1, 83-97. Abstract Eye movement desensitization and reprocessing (EMDR) is a recently developed psychotherapy method which appears to increase efficiency in treating trauma-based psychological disturbance. Applications to child tr eatment were explored in five case



Embryonic Origin of Gustatory Cranial Sensory Neurons  

PubMed Central

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), while 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, while 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 while neural crest-derived neurons provide general epithelial innervation to the oral cavity.

Harlow, Danielle E.; Barlow, Linda A.



Leptin resistance and desensitization of hypophagia during prolonged inflammatory challenge.  


Acute exposure to bacterial lipopolysaccharide (LPS) is a potent inducer of immune response as well as hypophagia. Nevertheless, desensitization of responses to LPS occurs during long-term exposure to endotoxin. We induced endotoxin tolerance, injecting repeated (6LPS) LPS doses compared with single (1LPS) treatment. 1LPS, but not 6LPS group, showed decreased food intake and body weight, which was associated with an increased plasma leptin and higher mRNA expression of OB-Rb, MC4R, and SOCS3 in the hypothalamus. Hypophagia induced by 1LPS was associated with lower levels of 2-arachidonoylglycerol (2-AG), increased number of p-STAT3 neurons, and decreased AMP-activated protein kinase (AMPK) activity. Desensitization of hypophagia in the 6LPS group was related to high 2-AG, with no changes in p-STAT3 or increased p-AMPK. Leptin decreased food intake, body weight, 2-AG levels, and AMPK activity and enhanced p-STAT3 in control rats. However, leptin had no effects on 2-AG, p-STAT3, or p-AMPK in the 1LPS and 6LPS groups. Rats treated with HFD to induce leptin resistance showed neither hypophagia nor changes in p-STAT3 after 1LPS, suggesting that leptin and LPS recruit a common signaling pathway in the hypothalamus to modulate food intake reduction. Desensitization of hypophagia in response to repeated exposure to endotoxin is related to an inability of leptin to inhibit AMPK phosphorylation and 2-AG production and activate STAT3. SOCS3 is unlikely to underlie this resistance to leptin signaling in the endotoxin tolerance. The present model of prolonged inflammatory challenge may contribute to further investigations on mechanisms of leptin resistance. PMID:21343543

Borges, Beatriz C; Rorato, Rodrigo; Avraham, Yosefa; da Silva, Lilian E C M; Castro, Margaret; Vorobiav, Lia; Berry, Elliot; Antunes-Rodrigues, Jose; Elias, Lucila L K



Desensitization of the nicotinic acetylcholine receptor: molecular mechanisms and effect of modulators.  


1. Loss of response after prolonged or repeated application of stimulus is generally termed desensitization. A wide variety of phenomena occurring in living organisms falls under this general definition of desensitization. There are two main types of desensitization processes: specific and non-specific. 2. Desensitization of the nicotinic acetylcholine receptor is triggered by prolonged or repeated exposure to agonists and results in inactivation of its ion channel. It is a case of specific desensitization and is an intrinsic molecular property of the receptor. 3. Desensitization of the nicotinic acetylcholine receptor at the neuromuscular junction was first reported by Katz and Thesleff in 1957. Desensitization of the receptor has been demonstrated by rapid kinetic techniques and also by the characteristic "burst kinetics" obtained from single-channel recordings of receptor activity in native as well as in reconstituted membranes. In spite of a number of studies, the detailed molecular mechanism of the nicotinic acetylcholine receptor desensitization is not known with certainty. The progress of desensitization is accompanied by an increase in affinity of the receptor for its agonist. This change in affinity is attributed to a conformational change of the receptor, as detected by spectroscopic and kinetic studies. A four-state general model is consistent with the major experimental observations. 4. Desensitization of the nicotinic acetylcholine receptor can be potentially modulated by exogenous and endogenous substances and by covalent modifications of the receptor structure. Modulators include the noncompetitive blockers, calcium, the thymic hormone peptides (thymopoietin and thymopentin), substance P, the calcitonin gene-related peptide, and receptor phosphorylation. Phosphorylation is an important posttranslational covalent modification that is correlated with the regulation and desensitization of the receptor through various protein kinases. 5. Although the physiological significance of desensitization of the nicotinic receptor is not yet fully understood, desensitization of receptors probably plays a significant role in the operation of the neuronal networks associated in memory and learning processes. Desensitization of the nicotinic receptor could also possibly be related to the neuromuscular disease, myasthenia gravis. PMID:2663167

Ochoa, E L; Chattopadhyay, A; McNamee, M G



Clinical applications of drug desensitization in the Asia-Pacific region  

PubMed Central

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.



Sexual violence: psychiatric healing with eye movement reprocessing and desensitization.  


Sexual violence, which affects one in three women worldwide, can result in significant psychiatric morbidity and suicide. Eye movement desensitization and reprocessing (EMDR) offers health care providers the option of a brief psychiatric intervention that can result in psychiatric healing in as few as four sessions. Because health care providers often hear stories of sexual violence from their patients, they are in an ideal position to make recommendations for treatment. The purpose of this article is to introduce health care providers to the technique of EMDR, review safety and appropriateness, and discuss clinical and research implications. PMID:20623397

Posmontier, Bobbie; Dovydaitis, Tiffany; Lipman, Kenneth



Molecular mechanisms that desensitize metabotropic glutamate receptor signaling: an overview.  


The purpose of the present article is to review our actual knowledge on the desensitization of metabotropic glutamate receptors based on the literature available so far, with the attempt to emphasize all converging data and to give a possible explanation to those evidences that still remain controversial. 1. We review our knowledge on the regulation of mGlu receptors based on the available literature 2. We report converging data and we comment on issues that still remain controversial. This article is part of a Special Issue entitled 'Metabotropic Glutamate Receptors'. PMID:22659473

Iacovelli, Luisa; Nicoletti, Ferdinando; De Blasi, Antonio



Phrenic nerve conduction study in demyelinating neuropathies and open-heart surgery  

Microsoft Academic Search

Objectives: The aim of this study was to determine normal values of phrenic nerve conduction (PNC) in healthy individuals; to evaluate the subclinical extent of phrenic nerve involvement in Guillain–Barré syndrome (G-B) and hereditary motor and sensory neuropathy-I (HMSN-I), and to evaluate phrenic nerve damage after cardiac surgery.Materials and methods: PNC was performed by transcutaneous stimulation in the neck and

A Cruz-Martinez; A Armijo; A Fermoso; S Moraleda; I Maté; M Mar??n



Schwann cells seeded in acellular nerve grafts improve functional recovery.  


Introduction: This study evaluated whether Schwann cells (SCs) from different nerve sources transplanted into cold-preserved acellular nerve grafts (CP-ANGs) would improve functional regeneration compared to nerve isografts. Methods: SCs isolated and expanded from motor and sensory branches of rat femoral and sciatic nerves were seeded into 14mm CP-ANGs. Growth factor expression, axonal regeneration, and functional recovery were evaluated in a14 mm rat sciatic injury model and compared to isografts. Results: At 14 days, motor or sensory-derived SCs increased expression of growth factors in CP-ANGs versus isografts. After 42 days, histomorphometric analysis found CP-ANGs with SCs and isografts had similar numbers of regenerating nerve fibers. At 84 days, muscle force generation was similar for CP-ANGs with SCs and isografts. SC source did not affect nerve fiber counts or muscle force generation. Discussion: SCs transplanted into CP-ANGs increase functional regeneration to isograft levels; however SC nerve source did not have an effect. © 2013 Wiley Periodicals, Inc. PMID:23625513

Jesuraj, Nithya J; Santosa, Katherine B; Macewan, Matthew R; Moore, Amy M; Kasukurthi, Rahul; Ray, Wilson Z; Flagg, Eric R; Hunter, Daniel A; Borschel, Gregory H; Johnson, Philip J; Mackinnon, Susan E; Sakiyama-Elbert, Shelly E



Sensory testing in leprosy: comparison of ballpoint pen and monofilaments.  


The 10 g monofilament has been replaced by the ballpoint pen in routine sensory testing of nerves in leprosy control in Ethiopia. Results of sensory testing between the ballpoint pen and different monofilaments on hands and feet were compared. Ballpoint pen underdiagnosis of loss of sensation was defined to occur when the pen was felt and the monofilament was not. Differences were evaluated both for individual test points (test point level) and for the test points of extremities collectively (extremity level). An extremity (either a hand or a foot) was defined as having sensory nerve function impairment (SNFI) if a supplying nerve had SNFI, which was the case when sensation was absent in two or more test points in the area supplied by that nerve. At test point level, the percentages with ballpoint pen underdiagnosis relative to the 2, 10, 20 and 50 g monofilaments were 40, 21, 9 and 7%, respectively, in the hands, and 47, 30, 15 and 7% in the feet. Ballpoint pen underdiagnosis percentages of SNFI at extremity level were 32, 18, 8 and 9% in the hands, and 37, 26, 14 and 6% in the feet. The risk of ballpoint pen underdiagnosis appears to be higher in extremities without visible damage. In conclusion, substantial levels of underdiagnosis of sensory loss with the ballpoint pen were observed. However, the consequences for the prognosis of treatment with corticosteroids in patients with the more subtle sensation loss noted here need to be established. Development and testing of guidelines is a prerequisite for the use of the ballpoint pen. PMID:12669932

Koelewijn, L F; Meima, A; Broekhuis, S M; Richardus, J H; Mitchell, P D; Benbow, C; Saunderson, P R



Detection of hereditary motor sensory neuropathy type I in childhood.  

PubMed Central

Clinical signs and slowed motor nerve conduction velocities were found in 17 of 36 children under 10 years of age who had one parent with hereditary motor sensory neuropathy type I (HMSN I). Four children had slowed conduction velocities at one year or less. Clinical signs were subtle and included pes planus, distal foot wasting, weakness of ankle eversion and dorsiflexion and areflexia. HMSN I can be detected reliably in children, even before one year of age.

Feasby, T E; Hahn, A F; Bolton, C F; Brown, W F; Koopman, W J



The pathology of the ulnar nerve in acromegaly  

Microsoft Academic Search

Context: Acromegalic patients may complain of sensory disturbances in their hands. Cubital tunnel syndrome, the ulnar nerve neuropathy at the cubital tunnel (UCT), in acromegalic patients has never been reported. Objective: To describe and assess the prevalence of UCT in acromegalic patients and the effects of 1 year of therapy on UCT. Patients: We examined prospectively 37 acromegalic patients with

Alberto Tagliafico; Eugenia Resmini; Raffaella Nizzo; Lorenzo E. Derchi; Francesco Minuto; Massimo Giusti; Carlo Martinoli; Diego Ferone



Compression of the digital nerves by a giant periosteal chondroma.  


We describe a left-handed man who had a giant periosteal chondroma of the proximal phalanx of the left third finger with compression of the digital neurovascular structures, and the flexor and extensor tendons. Cutaneous pressure thresholds of the digital nerves were tested, showing complete sensory recovery 24 months postoperatively. PMID:23245470

Santanelli, Fabio; Paolini, Guido; Longo, Benedetto; Laporta, Rosaria; Pagnoni, Marco



Afferents of cranial sensory ganglia pathfind to their target independent of the site of entry into the hindbrain.  


In vertebrates, sensory neurons interconnect a variety of peripheral tissues and central targets, conveying sensory information from different types of sensory receptors to appropriate second-order neurons in the central nervous system (CNS). To explore the possibility that the different rhombomere environments where sensory neurons enter into the hindbrain affect the pathfinding capability of growth cones, we studied the development of the VIIIth ganglion afferent both in vivo and in vitro. We focused on the vestibular nerve because it is the only cranial nerve projecting to the cerebellum, allowing for ready identification from its pattern of projection. Embryonic rat brain was cut along the dorsal midline and, with the VIIIth and Vth ganglia still attached, flat mounted and visualized with antibodies specific for sensory ganglia. Axons reached the cerebellar primordium at embryonic day (E) 13, then splayed out towards the edges of the rhombic lip of rostral hindbrain. In vitro, the VIIIth ganglion showed development similar to that in vivo and innervated the cerebellum, an appropriate target, indicating that mechanisms for axon guidance and target recognition are preserved in vitro. When the VIIIth ganglion was transplanted to the position of the Vth ganglion, axons from the transplanted ganglion entered the cerebellar primordium with a trajectory characteristic of the VIIIth nerve. These results indicate that the central projection pattern of the VIIIth nerve is not affected by the environment of nerve entry into the brainstem, suggesting that axons of sensory cranial ganglion intrinsically possess the capacity to find their target correctly. PMID:10701868

Tashiro, Y; Endo, T; Shirasaki, R; Miyahara, M; Heizmann, C W; Murakami, F



Sensory marketing: the multi-sensory brand-experience concept  

Microsoft Academic Search

Purpose – The purpose of this paper is to present the multi-sensory brand-experience concept in relation to the human mind and senses. It also seeks to propose a sensory marketing (SM) model of the multi-sensory brand-experience hypothesis. Design\\/methodology\\/approach – This paper applies exploratory and explanatory approaches to investigating the multi-sensory brand-experience concept within the context of discovery. The qualitative study

Bertil Hultén



Termino-lateral nerve suture in lesions of the digital nerves: clinical experience and literature review.  


Documented experience of treatment of digital nerve lesions with the termino-lateral (end-to-side) nerve suture is limited. Our clinical experience of this technique is detailed here alongside a systematic review of the previous literature. We performed, from 2002 to 2008, seven termino-lateral sutures with epineural window opening for digital nerve lesions. Functional outcome was analysed using the two-point discrimination test and the Semmes-Weinstein monofilament test. The results showed a sensory recovery of S3+ in six cases and S3 in one case. The mean distance found in the two-point discrimination test was 12.7 mm (range 8-18 mm). After a review of the literature, we were able to obtain homogeneous data from 17 additional patients operated by termino-lateral coaptation. The overall number of cases included in our review was 24. A sensory recovery was observed in 23 out of 24 patients. The functional results were S0 in one case, S3 in one case, S3+ in twenty cases and S4 in two cases. Excluding the one unfavourable case, the mean distance in the two-point discrimination test was 9.7 mm (range 3-18 mm). It can thus be concluded that the treatment of digital nerve lesions with termino-lateral suture showed encouraging results. Based on the results obtained in this current study we believe that in case of loss of substance, end-to-side nerve coaptation may be an alternative to biological and synthetic tubulisation when a digital nerve reconstruction by means of nerve autograft is declined by the patient. PMID:19687081

Artiaco, S; Tos, P; Conforti, L G; Geuna, S; Battiston, B



Regulation of ?-opioid receptors: desensitization, phosphorylation, internalization, and tolerance.  


Morphine and related µ-opioid receptor (MOR) agonists remain among the most effective drugs known for acute relief of severe pain. A major problem in treating painful conditions is that tolerance limits the long-term utility of opioid agonists. Considerable effort has been expended on developing an understanding of the molecular and cellular processes that underlie acute MOR signaling, short-term receptor regulation, and the progression of events that lead to tolerance for different MOR agonists. Although great progress has been made in the past decade, many points of contention and controversy cloud the realization of this progress. This review attempts to clarify some confusion by clearly defining terms, such as desensitization and tolerance, and addressing optimal pharmacological analyses for discerning relative importance of these cellular mechanisms. Cellular and molecular mechanisms regulating MOR function by phosphorylation relative to receptor desensitization and endocytosis are comprehensively reviewed, with an emphasis on agonist-biased regulation and areas where knowledge is lacking or controversial. The implications of these mechanisms for understanding the substantial contribution of MOR signaling to opioid tolerance are then considered in detail. While some functional MOR regulatory mechanisms contributing to tolerance are clearly understood, there are large gaps in understanding the molecular processes responsible for loss of MOR function after chronic exposure to opioids. Further elucidation of the cellular mechanisms that are regulated by opioids will be necessary for the successful development of MOR-based approaches to new pain therapeutics that limit the development of tolerance. PMID:23321159

Williams, John T; Ingram, Susan L; Henderson, Graeme; Chavkin, Charles; von Zastrow, Mark; Schulz, Stefan; Koch, Thomas; Evans, Christopher J; Christie, Macdonald J



Immunological mechanisms for desensitization and tolerance in food allergy1  

PubMed Central

Food allergy is a major public health concern in westernized countries, estimated to affect 5% of children and 3-4 % of adults. Allergen specific immunotherapy for food allergy is currently being actively evaluated, but is still experimental. The optimal protocol, in terms of the route of administration of the food, target maintenance dose, duration of maintenance therapy and the optimal patient for these procedures are still being worked out. The mechanisms underlying successful food desensitization are also unclear, in part because there is no standard immunotherapy protocol. The mechanisms involved however, may include mast cell and basophil suppression, development of food-specific IgG4 antibodies, reduction in the food specific IgE/IgG4 ratio, up-regulation and expansion of natural or inducible regulatory T cells, a skewing from a Th2 to a Th1 profile and the development of anergy and/or deletion in antigen specific cells. Additional studies are required to elucidate and understand these mechanisms by which desensitization and tolerance are achieved, and which may reveal valuable biomarkers for evaluating and following food allergic patients on immunotherapy.

Rachid, Rima; Umetsu, Dale T.



Sensory transduction in dorsal cutaneous mechanoreceptors of the frog, Rana pipiens  

Microsoft Academic Search

Summary 1.Sensory transduction was studied in dorsal skin mechanoreceptors of the frog,Rana pipiens. The skin was clamped and stretched before being stimulated with the tip of a glass rod mounted on a servo-controlled loudspeaker. Afferent activity was recorded extracellularly from a dorsal cutaneous nerve.2.Three groups of sensory units could be identified by the size of their recorded action potentials and

R. E. Watts; A. S. French



Hand dominance effect on median and ulnar sensory evoked amplitude and latency in asymptomatic workers  

Microsoft Academic Search

Objective: To examine the relative effect of hand dominance on the median and ulnar sensory evoked responses and grip strength in active workers.Design: A cross-sectional or survey design.Setting: Workers from 4 different sites underwent on-site testing of the median and ulnar sensory nerves in both hands (antidromic stimulation, 14cm), and testing of bilateral grip strength.Patients: 224 workers, asymptomatic of hand,

Robert A. Werner; Alfred Franzblau



Structured Sensory Trauma Interventions  

ERIC Educational Resources Information Center

|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…

Steele, William; Kuban, Caelan



Recording Sensory Words  

ERIC Educational Resources Information Center

|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…

Ashbrook, Peggy




Microsoft Academic Search





Sensory Transduction: Getting the Message  

NSDL National Science Digital Library

This lecture covers the sensory system. More specifically, it provides information about how the sensory system captures, transduces, amplifies, adapts, and passes information from one cell to the next.

A. James Hudspeth, Ph.D., M.D. (Howard Hughes Medical Institute;)



Improvement of Sciatic Nerve Regeneration Using Laminin-Binding Human NGF-?  

PubMed Central

Background Sciatic nerve injuries often cause partial or total loss of motor, sensory and autonomic functions due to the axon discontinuity, degeneration, and eventual death which finally result in substantial functional loss and decreased quality of life. Nerve growth factor (NGF) plays a critical role in peripheral nerve regeneration. However, the lack of efficient NGF delivery approach limits its clinical applications. We reported here by fusing with the N-terminal domain of agrin (NtA), NGF-? could target to nerve cells and improve nerve regeneration. Methods Laminin-binding assay and sustained release assay of NGF-? fused with NtA (LBD-NGF) from laminin in vitro were carried out. The bioactivity of LBD-NGF on laminin in vitro was also measured. Using the rat sciatic nerve crush injury model, the nerve repair and functional restoration by utilizing LBD-NGF were tested. Findings LBD-NGF could specifically bind to laminin and maintain NGF activity both in vitro and in vivo. In the rat sciatic nerve crush injury model, we found that LBD-NGF could be retained and concentrated at the nerve injury sites to promote nerve repair and enhance functional restoration following nerve damages. Conclusion Fused with NtA, NGF-? could bind to laminin specifically. Since laminin is the major component of nerve extracellular matrix, laminin binding NGF could target to nerve cells and improve the repair of peripheral nerve injuries.

Sun, Wenjie; Sun, Changkai; Zhao, Hui; Lin, Hang; Han, Qianqian; Wang, Jingyu; Ma, Hui; Chen, Bing; Xiao, Zhifeng; Dai, Jianwu



A tingling sanshool derivative excites primary sensory neurons and elicits nocifensive behavior in rats  

PubMed Central

Szechuan peppers contain hydroxy-?-sanshool that imparts desirable tingling, cooling, and numbing sensations. Hydroxy-?-sanshool activates a subset of sensory dorsal root ganglion (DRG) neurons by inhibiting two-pore potassium channels. We presently investigated if a tingle-evoking sanshool analog, isobutylalkenyl amide (IBA), excites rat DRG neurons and, if so, if these neurons are also activated by agonists of TRPM8, TRPA1, and/or TRPV1. Thirty-four percent of DRG neurons tested responded to IBA, with 29% of them also responding to menthol, 29% to cinnamic aldehyde, 66% to capsaicin, and subsets responding to two or more transient receptor potential (TRP) agonists. IBA-responsive cells had similar size distributions regardless of whether they responded to capsaicin or not; cells only responsive to IBA were larger. Responses to repeated application of IBA at a 5-min interstimulus interval exhibited self-desensitization (tachyphylaxis). Capsaicin did not cross-desensitize responses to IBA to any greater extent than the tachyphylaxis observed with repeated IBA applications. These findings are consistent with psychophysical observations that IBA elicits tingle sensation accompanied by pungency and cooling, with self-desensitization but little cross-desensitization by capsaicin. Intraplantar injection of IBA elicited nocifensive responses (paw licking, shaking-flinching, and guarding) in a dose-related manner similar to the effects of intraplantar capsaicin and serotonin. IBA had no effect on thermal sensitivity but enhanced mechanical sensitivity at the highest dose tested. These observations suggest that IBA elicits an unfamiliar aversive sensation that is expressed behaviorally by the limited response repertoire available to the animal.

Klein, Amanda H.; Sawyer, Carolyn M.; Zanotto, Karen L.; Ivanov, Margaret A.; Cheung, Susan; Carstens, Mirela Iodi; Furrer, Stephan; Simons, Christopher T.; Slack, Jay P.



Neurovascular compression in cranial nerve and systemic disease.  

PubMed Central

As we age, our arteries elongate and our brains "sag." As a consequence of these processes, redundant arterial loops and bridging or intrinsic hindbrain veins may cause cross-compression of cranial nerve root entry zones in the cerebellopontine angle. This pulsatile compression can be seen to produce hyperactive dysfunction of the cranial nerve. Symptoms of trigeminal or glossopharyngeal neuralgia (somatic sensory), hemifacial spasm (somatic motor), tinnitus and vertigo (special sensory) and some cases of "essential" hypertension are caused by these vessels compressing cranial nerves V, IX--X, VII, VIII, and left X and medulla oblongata. Using microsurgical techniques, the symptoms may be relieved by vascular decompression, findings and results in 695 paients are briefly reviewed and correlated. A chronic primate model of "essential" hypertension is briefly described.

Jannetta, P J



Desensitization of mammalian. beta. -adrenergic receptors: receptor sequestration vs. receptor function  

SciTech Connect

Human A431 and rat glioma C6 cells exposed to isoproterenol (ISO) underwent a time and dose dependent loss of ISO-stimulated adenylate cyclase (AC) activity (desensitization). In addition, ..beta..-adrenergic receptors (..beta..AR) became less accessible to the hydrophilic antagonist (/sup 3/H)CGP-12177 and redistributed from the heavier density plasma membrane fraction to a lighter density membrane fraction (sequestration). Pretreatment of the cells with Concanavalin A (Con A) or phenylarsine oxide blocked sequestration but not desensitization. ..beta..AR of membranes prepared from Con A-pretreated cells exhibited a reduced affinity for ISO after desensitization as measured by the half-maximal concentration of ISO required to stimulate AC (Kact) and to compete for antagonist binding (IC50). Membranes were exposed to alkali to inactivate AC and ..beta..AR was transferred to a foreign AC by membrane fusion with polyethylene glycol. ..beta..AR from desensitized cells exhibited a reduced affinity for ISO (both Kact and IC50) and a reduced ability to stimulate the foreign AC. In addition, ..beta..AR from desensitized cells remained accessible to (/sup 3/H)CGP-12177 in the fused membranes. The authors conclude that the primary, essential step in desensitization is a reduction in ..beta..AR function. In contrast, ..beta..AR sequestration is not a prerequisite but a secondary event in the desensitization process.

Kassis, S.; Olasmaa, M.; Fishman, P.H.



Dr. Henry Head and lessons learned from his self-experiment on radial nerve transection.  


In this paper the authors aim to review Dr. Henry Head's famous and dramatic nerve sectioning experiment. They discuss the implications of his experimental approach as well as the effect his experiment had on the field of neurology. Henry Head was a prominent British neurologist who contributed greatly to the understanding of the sensory examination through an experiment in which he had his own radial nerve transected. Head carefully documented the sensory changes following the sectioning. He hypothesized the existence of two separate sensory systems: protopathic and epicritic. Head was one of the first scientists to speculate on sensory dissociation, and his writings generated both enthusiasm and controversy. Although the ethical issue of self-experimentation was raised by his bold experiment and many aspects of his investigations and conclusions have been criticized, Head undoubtedly contributed important clinical lessons to neurology. Arguably, Henry Head's greatest contribution was the realization that the neurological portion of the sensory examination was anything but straightforward. PMID:20932092

Lenfest, Stephen M; Vaduva-Nemes, Andreea; Okun, Michael S



Sensory characterisation of wine vinegars  

Microsoft Academic Search

Ninety-six samples of vinegars of different sources were subjected to sensory analysis. For white vinegars, Linear Discriminant Analysis showed that sensory analysis could be used to distinguish between the different sources of vinegar, and especially to discriminate between alcohol and apple vinegars from wine vinegars on the basis of only seven sensory parameters. Principal Component Regression showed that the quality

Vincenzo Gerbi; Giuseppe Zeppa; Andrea Antonelli; Alberta Carnacini



Understanding Sensory Integration. ERIC Digest.  

ERIC Educational Resources Information Center

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…

DiMatties, Marie E.; Sammons, Jennifer H.


Sensory signaling in Caenorhabditis elegans  

Microsoft Academic Search

The simple anatomy, behavior, and genetics of the nematode Caenorhabditis elegans make it an attractive organism for studying sensory circuits and their functions in vivo. Recent advances in our understanding of C. elegans sensory signaling stem from work on topographic maps, chemosensory receptors, modality coding, and the integration of antagonistic sensory inputs.

Joshua M Kaplan



A peroxynitrite decomposition catalyst counteracts sensory neuropathy in streptozotocin-diabetic mice  

Microsoft Academic Search

Whereas an important role of free radicals and oxidants in peripheral diabetic neuropathy is well established, the contribution of nitrosative stress and, in particular, of the highly reactive oxidant peroxynitrite, has not been properly explored. Our previous findings implicate peroxynitrite in diabetes-associated motor and sensory nerve conduction deficits and peripheral nerve energy deficiency and poly(ADP-ribose) polymerase activation associated with Type

Viktor R. Drel; Pal Pacher; Igor Vareniuk; Ivan Pavlov; Olga Ilnytska; Valeriy V. Lyzogubov; Jyoti Tibrewala; John T. Groves; Irina G. Obrosova



Peripheral nerve regeneration and neurotrophic factors  

PubMed Central

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.




Characterising the Mechanism of Airway Smooth Muscle ?2 Adrenoceptor Desensitization by Rhinovirus Infected Bronchial Epithelial Cells  

PubMed Central

Rhinovirus (RV) infections account for approximately two thirds of all virus-induced asthma exacerbations and often result in an impaired response to ?2 agonist therapy. Using an in vitro model of RV infection, we investigated the mechanisms underlying RV-induced ?2 adrenoceptor desensitization in primary human airway smooth muscle cells (ASMC). RV infection of primary human bronchial epithelial cells (HBEC) for 24 hours produced conditioned medium that caused ?2 adrenoceptor desensitization on ASMCs without an effect on ASMCs viability. Less than 3 kDa size fractionation together with trypsin digestion of RV-induced conditioned medium did not prevent ?2 adrenoceptor desensitization, suggesting it could potentially be mediated by a small peptide or lipid. RV infection of BECs, ASMCs and fibroblasts produced prostaglandins, of which PGE2, PGF2? and PGI2 had the ability to cause ?2 adrenoceptor desensitization on ASMCs. RV-induced conditioned medium from HBECs depleted of PGE2 did not prevent ASMC ?2 adrenoceptor desensitization; however this medium induced PGE2 from ASMCs, suggesting that autocrine prostaglandin production may be responsible. Using inhibitors of cyclooxygenase and prostaglandin receptor antagonists, we found that ?2 adrenoceptor desensitization was mediated through ASMC derived COX-2 induced prostaglandins. Since ASMC prostaglandin production is unlikely to be caused by RV-induced epithelial derived proteins or lipids we next investigated activation of toll-like receptors (TLR) by viral RNA. The combination of TLR agonists poly I:C and imiquimod induced PGE2 and ?2 adrenoceptor desensitization on ASMC as did the RNA extracted from RV-induced conditioned medium. Viral RNA but not epithelial RNA caused ?2 adrenoceptor desensitization confirming that viral RNA and not endogenous human RNA was responsible. It was deduced that the mechanism by which ?2 adrenoceptor desensitization occurs was by pattern recognition receptor activation of COX-2 induced prostaglandins.

Van Ly, David; Faiz, Alen; Jenkins, Christine; Crossett, Ben; Black, Judith L.; McParland, Brent; Burgess, Janette K.; Oliver, Brian G. G.



Small Nerve Fiber Pathology in Critical Illness  

PubMed Central

Background Degeneration of intraepidermal nerve fibers (IENF) is a hallmark of small fiber neuropathy of different etiology, whose clinical picture is dominated by neuropathic pain. It is unknown if critical illness can affect IENF. Methods We enrolled 14 adult neurocritical care patients with prolonged intensive care unit (ICU) stay and artificial ventilation (? 3 days), and no previous history or risk factors for neuromuscular disease. All patients underwent neurological examination including evaluation of consciousness, sensory functions, muscle strength, nerve conduction study and needle electromyography, autonomic dysfunction using the finger wrinkling test, and skin biopsy for quantification of IENF and sweat gland innervation density during ICU stay and at follow-up visit. Development of infection, sepsis and multiple organ failure was recorded throughout the ICU stay. Results Of the 14 patients recruited, 13 (93%) had infections, sepsis or multiple organ failure. All had severe and non-length dependent loss of IENF. Sweat gland innervation was reduced in all except one patient. Of the 7 patients available for follow-up visit, three complained of diffuse sensory loss and burning pain, and another three showed clinical dysautonomia. Conclusions Small fiber pathology can develop in the acute phase of critical illness and may explain chronic sensory impairment and pain in neurocritical care survivors. Its impact on long term disability warrants further studies involving also non-neurologic critical care patients.

Latronico, Nicola; Filosto, Massimiliano; Fagoni, Nazzareno; Gheza, Laura; Guarneri, Bruno; Todeschini, Alice; Lombardi, Raffaella; Padovani, Alessandro; Lauria, Giuseppe



Successful interferon desensitization in a patient with chronic hepatitis C infection  

PubMed Central

Treatment of hepatitis C, even when absolutely necessary, is almost impossible when interferon cannot be administered for any reason. We report a 65-year-old patient with chronic hepatitis C virus (HCV) infection and fibrosis, who was unable to receive interferon because of systemic hypersensitivity. The patient was desensitized successfully through gradual incremental exposure to interferon, and HCV infection was eradicated after a complete course of treatment, with no further allergic reactions. This case report that describes successful eradication of hepatitis C in a patient with advanced liver disease after desensitization to interferon revealed that desensitization may not necessarily damage the therapeutic efficacy of the drug.

Taghavi, Seyed Alireza; Eshraghian, Ahad



Sensory innervation of gingival and alveolar mucosa of the house musk shrew (Suncus murinus).  


The lingual gingival and the alveolar mucosa of mandible of the house musk shrew (Suncus murinus) were stained by methylene blue vital staining or osmic acid staining, and mounted as whole thickness preparations. The sensory innervation and the distribution of sensory receptors were investigated with a light microscope. The nerve fibers supplying these regions derive from the sublingual nerve, which ascend in the mucosa as they branch out. Sensory receptors found in the present study are of four kinds; free nerve endings, bush-like nerve endings, Merkel cell-neurite complexes and encapsulated corpuscles. The Merkel cell-neurite complexes were scarce and localized in the upper margin of gingival mucosa. The bush-like nerve endings were distributed preferentially in the alveolar mucosa, in which their maximum density was 9-23 per mm2. Among the organized receptors, the encapsulated corpuscles appeared most frequently throughout the mucosal area investigated, and their maximum density amounted to 27-56 per mm2 in the gingival mucosa. These corpuscles were relatively small and poorly differentiated. Although the bush-like nerve endings and the encapsulated corpuscles were fewer in the third molar region, there was no obvious regional difference in their distribution densities from the premolar region to the second molar region. PMID:2435019

Yamamoto, T; Sakada, S



Engineering a multimodal nerve conduit for repair of injured peripheral nerve  

NASA Astrophysics Data System (ADS)

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.

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.



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


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

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



[Electrophysiological study of the lateral dorsal cutaneous nerve: technical applicability and normal values].  


The distal nerve conduction study of the long nerve in the leg is more efficient to work with so that it can establish the early diagnosis of the majority of polyneuropathies. The main purpose of this study is the technical applicability of the orthodromic neural conduction examination of the dorsal cutaneous branch of the sural nerve (lateral dorsal cutaneous nerve) on healthy people, and define the normal values used as references to compare with the proximal segment. Forty five persons mean age 41.56 years old (range 19-75) were examined, and the sensory nerve action potentials were registered from ninety feet. The active recording superficial electrode was placed below and behind the lateral malleolus and the stimulating electrode was placed 10 cm distal to the recording superficial electrode at the dorsal lateral aspect of the feet. The mean value for the lateral dorsal cutaneous nerve conduction velocity was 47.35 +/- 4.8 m/s and for amplitudes 4.19 +/- 1.9 microV. The sensory conduction velocity in the distal segment was 14% lower than the proximal one. The sensory nerve action potential amplitude of the distal segment was 73% lower than the proximal one. The lower normal limit recommended for conduction velocity of this nerve plus correction for skin temperature of 34 degrees C is 38 m/s. Some differences in amplitude and conduction velocity among group ages are to be considered. PMID:10849624

Dias, R J; Carneiro, A P



Algal Sensory Chemical Ecology  

Microsoft Academic Search

Sensory chemical ecology is the branch of chemical ecology that focuses on chemical communications between organisms and chemical\\u000a sensing of the environment by organisms. Algae are well known to have numerous physiological responses to variations in their\\u000a chemical environment, particularly with respect to nutrients (Lobban and Harrison 1994). However, with respect to environmental\\u000a sensing it is typical for “chemical ecology”

Charles D. Amsler


Assessment of the Medial Dorsal Cutaneous, Dorsal Sural, and Medial Plantar Nerves in Impaired Glucose Tolerance and Diabetic Patients With Normal Sural and Superficial Peroneal Nerve Responses  

PubMed Central

OBJECTIVE This study evaluated the nerve conduction study (NCS) parameters of the most distal sensory nerves of the lower extremities—namely, the medial dorsal cutaneous (MDC), dorsal sural (DS), and medial plantar (MP) nerves—in diabetic (DM) and impaired glucose tolerance (IGT) patients who displayed normal findings on their routine NCSs. RESEARCH DESIGN AND METHODS Standard NCSs were performed on healthy control (HC), DM, and IGT groups (N = 147). The bilateral NCS parameters of the MDC, DS, and MP nerves were investigated. The Toronto Clinical Scoring System (TCSS) was assessed for the DM and IGT groups. RESULTS The mean TCSS scores of the IGT and DM groups were 2.5 ± 2.3 and 2.8 ± 2.2, respectively. No significant differences between the two groups were observed. After adjustment of age and BMI, the DM group showed significant NCS differences in DS and MDC nerves compared with the HC group (P < 0.05). These differences were also exhibited in the left DS of the IGT group (P = 0.0003). More advanced NCS findings were observed in the DM group. Bilateral abnormal NCS responses in these distal sensory nerves were found in 40 and 16% of DM and IGT patients, respectively. CONCLUSIONS These results showed that the simulta