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Sample records for rat median nerve

  1. Does Pulsed Magnetic Field Therapy Influence Nerve Regeneration in the Median Nerve Model of the Rat?

    PubMed Central

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

    2014-01-01

    The aim of this study was to evaluate the impact of pulsed magnetic field therapy on peripheral nerve regeneration after median nerve injury and primary coaptation in the rat. Both median nerves were surgically exposed and denervated in 24 female Wistar rats. A microsurgical coaptation was performed on the right side, whereas on the left side a spontaneous healing was prevented. The study group underwent a daily pulsed magnetic field therapy; the other group served as a control group. The grasping force was recorded 2 weeks after the surgical intervention for a period of 12 weeks. The right median nerve was excised and histologically examined. The histomorphometric data and the functional assessments were analyzed by t-test statistics and one-way ANOVA. One-way ANOVA indicated a statistically significant influence of group affiliation and grasping force (P = 0.0078). Grasping strength was higher on a significant level in the experimental group compared to the control group permanently from the 9th week to the end of the study. T-test statistics revealed a significantly higher weight of the flexor digitorum sublimis muscle (P = 0.0385) in the experimental group. The histological evaluation did not reveal any statistically significant differences concerning the histomorphometric parameters. Our results suggest that the pulsed magnetic field therapy has a positive influence on the functional aspects of neural regeneration. More studies are needed to precisely evaluate and optimize the intensity and duration of the application. PMID:25143937

  2. High Median Nerve Injuries.

    PubMed

    Isaacs, Jonathan; Ugwu-Oju, Obinna

    2016-08-01

    The median nerve serves a crucial role in extrinsic and intrinsic motor and sensory function to the radial half of the hand. High median nerve injuries, defined as injuries proximal to the anterior interosseous nerve origin, therefore typically result in significant functional loss prompting aggressive surgical management. Even with appropriate recognition and contemporary nerve reconstruction, however, motor and sensory recovery may be inadequate. With isolated persistent high median nerve palsies, a variety of available tendon transfers can improve key motor functions and salvage acceptable use of the hand. PMID:27387077

  3. Functional and morphological assessment of a standardized crush injury of the rat median nerve.

    PubMed

    Ronchi, G; Nicolino, S; Raimondo, S; Tos, P; Battiston, B; Papalia, I; Varejão, A S P; Giacobini-Robecchi, M G; Perroteau, I; Geuna, S

    2009-04-30

    The availability of effective experimental models for investigating nerve regeneration and designing new strategies for promoting this unique repair process is important. The aim of this study was to standardize a rat median nerve crush injury model using a non-serrated clamp exerting a compression force of 17.02 MPa for a duration of 30s. Results showed that functional recovery, evaluated by grasping test, was already detectable at day-12 and progressively increased until day-28 after which animal performance plateaued until the end of testing (day-42), reaching a range of 75-80% of pre-operative values. Morphological analysis on the median nerve segments, distal to the crush lesion, which were withdrawn at the end of the experiment showed that regenerated nerve fibers are significantly more numerous and densely packed; they are also smaller and have a thinner myelin sheath compared to controls. Together, these results provide a baseline characterization of the crush median nerve injury experimental model for its employment in the investigation of nerve regeneration research, especially when a reproducible regeneration process is required, such as for the study of biological mechanisms of peripheral nerve fiber regeneration or development of new therapeutic agents for promoting posttraumatic nerve repair. PMID:19428511

  4. Distal median nerve dysfunction

    MedlinePlus

    ... Names Neuropathy - distal median nerve Images Central nervous system and peripheral nervous system References Jarvik JG, Comstock BA, Kliot M, et al. Surgery versus non-surgical therapy for carpal tunnel syndrome: a randomized ... D. Disorders of peripheral nerves. In: Daroff RB, Fenichel GM, Jankovic J, ...

  5. Sensory perturbations using suture and sutureless repair of transected median nerve in rats.

    PubMed

    Shaikh, Sumaiya; Shortland, Peter; Lauto, Antonio; Barton, Matthew; Morley, John W; Mahns, David A

    2016-03-01

    The effects of changes to cold, mechanical, and heat thresholds following median nerve transection with repair by sutures (Su) or Rose Bengal adhesion (RA) were compared to sham-operated animals. Both nerve-injured groups showed a transient, ipsilateral hyposensitivity to mechanical and heat stimuli followed by a robust and long-lasting hypersensitivity (6-7 weeks) with gradual recovery towards pre-injury levels by 90 days post-repair. Both tactile and thermal hypersensitivity were seen in the contralateral limb that was similar in onset but differed in magnitude and resolved more rapidly compared to the injured limb. Prior to injury, no animals showed any signs of aversion to cold plate temperatures of 4-16 °C. After injury, animals showed cold allodynia, lasting for 7 weeks in RA-repaired rats before recovering towards pre-injury levels, but were still present at 12 weeks in Su-repaired rats. Additionally, sensory recovery in the RA group was faster compared to the Su group in all behavioural tests. Surprisingly, sham-operated rats showed similar bilateral behavioural changes to all sensory stimuli that were comparable in onset and magnitude to the nerve-injured groups but resolved more quickly compared to nerve-injured rats. These results suggest that nerve repair using a sutureless approach produces an accelerated recovery with reduced sensorimotor disturbances compared to direct suturing. They also describe, for the first time, that unilateral forelimb nerve injury produces mirror-image-like sensory perturbations in the contralateral limb, suggesting that the contralateral side is not a true control for sensory testing. The potential mechanisms involved in this altered behaviour are discussed. PMID:26899181

  6. Resuscitation therapy for traumatic brain injury-induced coma in rats: mechanisms of median nerve electrical stimulation

    PubMed Central

    Feng, Zhen; Zhong, Ying-jun; Wang, Liang; Wei, Tian-qi

    2015-01-01

    In this study, rats were put into traumatic brain injury-induced coma and treated with median nerve electrical stimulation. We explored the wake-promoting effect, and possible mechanisms, of median nerve electrical stimulation. Electrical stimulation upregulated the expression levels of orexin-A and its receptor OX1R in the rat prefrontal cortex. Orexin-A expression gradually increased with increasing stimulation, while OX1R expression reached a peak at 12 hours and then decreased. In addition, after the OX1R antagonist, SB334867, was injected into the brain of rats after traumatic brain injury, fewer rats were restored to consciousness, and orexin-A and OXIR expression in the prefrontal cortex was downregulated. Our findings indicate that median nerve electrical stimulation induced an up-regulation of orexin-A and OX1R expression in the prefrontal cortex of traumatic brain injury-induced coma rats, which may be a potential mechanism involved in the wake-promoting effects of median nerve electrical stimulation. PMID:26170820

  7. Characterization of tests of functional recovery after median and ulnar nerve injury and repair in the rat forelimb.

    PubMed

    Galtrey, Clare M; Fawcett, James W

    2007-03-01

    The majority of human peripheral nerve injuries occur in the upper limb but the majority of studies in the rat are performed in the hindlimb. The upper and lower limbs differ in dexterity and control by supraspinal systems, so an upper limb model is a better representation of the common form of human injury. The purpose of this study was to further develop a rat model involving lesions of the median and ulnar nerves. To produce different degrees of misdirection of axons following nerve repair, we studied nerve crush, cut and repair of the two nerves, and cut and repair with crossover. Assessment of functional recovery was performed using a battery of motor and sensory tests: the staircase test, which assesses skilled forepaw reaching; grip strength meter, which assesses grip strength; pawprint analysis, which assesses toe spread and print length; horizontal ladder, which assesses forepaw placement during skilled locomotion; modified Randall-Selitto device and electronic von Frey probes, which assess fine touch; and cold probes, which assess temperature sensation. All tests revealed deficits in forepaw function after nerve injury except the print length and modified Randall-Selitto device. The time course of functional recovery was observed over 15 weeks. The final degree of functional recovery achieved was related to the misdirection of axon regeneration. The tests that most clearly revealed the effects of axon misdirection on function were the skilled paw reaching and grip strength tests. The lesion model and functional tests that we have developed will be useful in testing therapeutic strategies for treating the consequences of inaccurate axon regeneration following peripheral nerve injury in humans. PMID:17374098

  8. Low Median Nerve Transfers (Opponensplasty).

    PubMed

    Chadderdon, Robert Christopher; Gaston, R Glenn

    2016-08-01

    Opposition is the placement of the thumb opposite the fingers into a position from which it can work. This motion requires thumb palmar abduction, flexion, and pronation, which are provided by the abductor pollicis brevis, flexor pollicis brevis (FPB), and opponens pollicis. In the setting of a median nerve palsy, this function is typically lost, although anatomic variations and the dual innervation of the FPB may prevent complete loss at times. There are multiple well described and accepted tendon transfers to restore opposition, none of which have been proven to be superior to the others. PMID:27387078

  9. Intraneural Venous Malformations of the Median Nerve

    PubMed Central

    González Rodríguez, Alba; Midón Míguez, José

    2016-01-01

    Venous malformations arising from the peripheral nerve are a rare type of vascular malformation. We present the first case of an intraneural venous malformation of the median nerve to be reported in a child and review the previous two cases of median nerve compression due to a venous malformation that have been reported. These cases presented with painless masses in the volar aspect of the wrist or with symptoms suggestive of carpal tunnel syndrome. Clinical suspicion should lead to the use of Doppler ultrasonography as the first-line diagnostic tool. Magnetic resonance imaging and histopathology can confirm the diagnosis, as phleboliths are pathognomonic of venous malformations. Surgical treatment appears to be the only modality capable of successfully controlling the growth of an intraneural malformation. Sclerotherapy and radiotherapy have never been used to treat this type of malformation. PMID:27462571

  10. The Mouse Median Nerve Experimental Model in Regenerative Research

    PubMed Central

    Buskbjerg Jager, Sara

    2014-01-01

    Sciatic nerve crush injury in rat animal model is one of the most common experimental models used in regenerative research. However, the availability of transgenic mouse for nerve regeneration studies is constantly increasing and, therefore, the shift from rat model to mouse model is, in some cases, necessary. Moreover, since most of the human nerve lesions occur in the upper limb, it is also advantageous to shift from sciatic nerve to median nerve. In this study we described an experimental model which involves lesions of the median nerve in the mouse. Data showed that the finger flexor muscle contraction strength, assessed to evaluate the motor function recovery, and reached values not different from the control already 20 days after injury. The degree of nerve regeneration evaluated with stereological methods in light microscopy showed that, 25 days after injury, the number of regenerated myelinated fibers was comparable to the control, but they were smaller with a thinner myelin thickness. Stereological analysis made in electron microscopy confirmed these results, although the total number of fibers quantified was significantly higher compared to light microscopy analysis, due to the very small size of some fibers that can be detected only in electron microscopy. PMID:25180190

  11. [Right median nerve injury following laparoscopic sigmoidectomy].

    PubMed

    Mizuno, Ju; Yonenaga, Kazumichi; Arita, Hideko; Hanaoka, Kazuo

    2008-06-01

    Brachial plexus injury has often occurred secondary to malposition of the patient during general anesthesia. We have experienced median nerve injury following laparoscopic sigmoidectomy. A 61-year-old man with diabetes and hypertension received laparoscopic sigmoidectomy under general and epidural anesthesia. Tracheal intubation was easy without excessive retroflextion of his neck after anesthesia induction with fentanyl, propofol, and vecuronium. Both his upper arms were abducted to 80 degrees and his elbows were extended on a padded arm board. The shoulder braces were placed over both his acromioclavicular joints. His head remained in neutral position. Anesthesia was maintained with air, oxygen, sevoflurane, fentanyl, and vecuronium using mepivacaine via epidural catheter. During surgical procedures, he was in a combined lithotomy and head down position at maximum of 20 degrees. The operative table was tilted to the right at maximum of 20 degrees. The operation was finished successfully in 2 hours and 40 minutes without a special event. Postoperatively, he complained of numbness of the first, second, and third digits, and the radial side of fourth digit in his right hand. The redness on both his shoulders was observed. Muscle weakness and motor disturbance were not observed. Orthopedic surgeon diagnosed him as right median nerve injury. His symptoms improved gradually by physical training and disappeared one week after the operation. We suspect that his right median nerve injury was caused by compression and stretching of the brachial plexus in head down position, right lateral tilt table, use of shoulder brace, laparoscopy, abduction of the upper arm, and extension of the elbow. In laparoscopic operation in head down position, we should avoid using the shoulder brace to minimize the risk of brachial plexus injury. The arms should be approximated to the sides as nearly as possible and the elbows should be gently flexed to unload the median nerve and relieve

  12. Median nerve schwannoma: A case and review of literature

    PubMed Central

    Padasali, Praveen S.; Shankaregowda, V. S.; Kshirsagar, Shriram D.

    2015-01-01

    We report a case of a median nerve schwannoma, a rare type of a benign tumor of Schwann cells that presents as a palpable and painful mass on the flexor aspect of the forearm. Schwannomas of the median nerve make up 0.1–0.3% of all hand tumors. Symptoms are caused by an entrapment syndrome resulting from the growing tumor. Pain is the most common complaint of schwannomas. Imaging studies include computed tomography and magnetic resonance imaging and ultrasound. It is difficult to differentiate schwanommas from neurofibromas solely on the basis of a radiological investigation. Tumors of the median nerve are diagnostically challenging and median nerve schwannomas are rare. Diagnostic pearls are described to facilitate a more accurate and timely diagnosis. These characteristics include mobility, Tinel's sign, S-100 histological staining, and Antoni patterns. With a correct diagnosis, the tumor can be extirpated with preservation of nerve function and a low risk of recurrence. PMID:26396609

  13. Clinical Outcomes following median to radial nerve transfers

    PubMed Central

    Ray, Wilson Z.; Mackinnon, Susan E.

    2010-01-01

    Purpose In this study the authors evaluate the clinical outcomes in patients with radial nerve palsy who underwent nerve transfers utilizing redundant fascicles of median nerve (innervating the flexor digitorum superficialis and flexor carpi radialis muscles) to the posterior interosseous nerve and the nerve to the extensor carpi radialis brevis. Methods A retrospective review of the clinical records of 19 patients with radial nerve injuries who underwent nerve transfer procedures using the median nerve as a donor nerve were included. All patients were evaluated using the Medical Research Council (MRC) grading system. Results The mean age of patients was 41 years (range 17 – 78 years). All patients received at least 12 months of follow-up (20.3 ± 5.8 months). Surgery was performed at a mean of 5.7 ± 1.9 months post-injury. Post-operative functional evaluation was graded according to the following scale: grades MRC 0/5 - MRC 2/5 were considered poor outcomes, while MRC of 3/5 was a fair result, MRC grade 4/5 was a good result, and grade 4+/5 was considered an excellent outcome. Seventeen patients (89%) had a complete radial nerve palsy while two patients (11%) had intact wrist extension but no finger or thumb extension. Post-operatively all patients except one had good to excellent recovery of wrist extension. Twelve patients recovered good to excellent finger and thumb extension, two patients had fair recovery, five patients had a poor recovery. Conclusions The radial nerve is a commonly injured nerve, causing significant morbidity in affected patients. The median nerve provides a reliable source of donor nerve fascicles for radial nerve reinnervation. This transfer was first performed in 1999 and evolved over the subsequent decade. The important nuances of both surgical technique and motor re-education critical for to the success of this transfer have been identified and are discussed. PMID:21168979

  14. Median nerve behavior at different wrist positions among older males

    PubMed Central

    Nakashima, Hiroki; Muraki, Satoshi

    2015-01-01

    The effect of wrist flexion-extension on the median nerve appearance, namely the cross-sectional area (MNCSA) and the longitudinal (D1) and vertical (D2) diameters, was investigated among older adults (N = 34). Ultrasound examination was conducted to examine the median nerve at different wrist angles (neutral; and 15°, 30°, and 45° extension and flexion), in both the dominant and nondominant hand. Median nerve behavior were significantly associated with wrist angle changes. The MNCSA at wrist flexion and extension were significantly smaller (P < .001) compared with the neutral position in both the dominant and nondominant hand. The D1 and D2 were significantly reduced at flexion (P < .001) and extension (P < .001), respectively, in both the dominant and nondominant hand. Our results suggest that a larger flexion-extension angle causes higher compression stress on the median nerve, leading to increased deformation of the MNCSA, D1, and D2 among older adults. PMID:25945317

  15. Myofibroma in the Palm Presenting with Median Nerve Compression Symptoms

    PubMed Central

    Sarkozy, Heidi

    2014-01-01

    Summary: A myofibroma is a benign proliferation of myofibroblasts in the connective tissue. Solitary myofibromas are a rare finding especially in an adult. We report a case of a 23-year-old man presenting with an enlarging mass over his right palm. The patient is an active weight lifter. He reported numbness and tingling in the median nerve distribution. Nerve conduction studies and magnetic resonance imaging scans suggested a tumor involving or compressing the median nerve. The final diagnosis of myofibroma was made only after the histopathological diagnosis. PMID:25426387

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

    PubMed Central

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

    2015-01-01

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

  17. Usefulness of additional measurements of the median nerve with ultrasonography.

    PubMed

    Claes, F; Meulstee, J; Claessen-Oude Luttikhuis, T T M; Huygen, P L M; Verhagen, W I M

    2010-12-01

    High resolution sonography is a relatively new diagnostic technique in diagnosing carpal tunnel syndrome (CTS). Normal values in different studies, however, vary and this makes their practical use difficult. The aim of this study was to establish normal values for the median nerve cross-sectional area (CSA) and to investigate the value of measuring additional parameters. Ninety-eight wrists of 29 women and 25 men without signs or symptoms of CTS were included. Width and circumference of the wrist were measured. The CSA of the median nerve at the level of the pisiform bone was measured using ultrasonography. We found a significant correlation between the CSA of the median nerve at the wrist and wrist circumference. Measuring wrist circumference will establish the upper level of normal more accurately compared to predictions solely based upon gender. This has important implications in diagnosing CTS with ultrasonography. PMID:20429021

  18. Schwannoma of the Median Nerve: Diagnosis Sometimes Delayed

    PubMed Central

    Boufettal, Monsef; Azouz, Mohamed; Rhanim, Abdelkarim; Abouzahir, Mohamed; Mahfoud, Mustapha; Bardouni, Ahmed El; Berrada, Mohamed S; Yaacoubi, Moradh El

    2014-01-01

    Schwannoma is a tumor that develops from nerve sheath. The authors report an unusual case of schwannoma of the median nerve (MN) that remained asymptomatic for four years. The diagnosis was based on MRI (magnetic resonance imaging) and histopathological examination. Surgical removal is usually curative. The asymptomatic character of the tumor and its slow evolution remain an essential factor in diagnosis delays. This tumor has a good prognosis with a low recurrence rate and potential for malignant transformation. PMID:25125990

  19. Intraneural hemangioma of the median nerve: A case report

    PubMed Central

    2008-01-01

    Hemangiomas of the median nerve are very rare and, so far, only ten cases of intraneural hemangioma of this nerve have been reported in the literature. We present a case of 14-year-old girl who had a soft tissue mass in the region of the left wrist with signs and symptoms of carpal tunnel syndrome. Total removal of the mass was achieved using microsurgical epineural and interfasicular dissection. The symptoms were relieved completely, after this procedure, without any neurologic deficit. On follow-up two years later, no recurrence was observed. Whenever a child or young adult patient presents with CTS the possibility of a hemangioma involving the median nerve should be kept in mind in the differential diagnosis. PMID:18294368

  20. Fascicular Topography of the Human Median Nerve for Neuroprosthetic Surgery

    PubMed Central

    Delgado-Martínez, Ignacio; Badia, Jordi; Pascual-Font, Arán; Rodríguez-Baeza, Alfonso; Navarro, Xavier

    2016-01-01

    One of the most sought-after applications of neuroengineering is the communication between the arm and an artificial prosthetic device for the replacement of an amputated hand or the treatment of peripheral nerve injuries. For that, an electrode is placed around or inside the median nerve to serve as interface for recording and stimulation of nerve signals coming from the fascicles that innervate the muscles responsible for hand movements. Due to the lack of a standard procedure, the electrode implantation by the surgeon is strongly based on intuition, which may result in poor performance of the neuroprosthesis because of the suboptimal location of the neural interface. To provide morphological data that can aid the neuroprosthetic surgeon with this procedure, we investigated the fascicular topography of the human median nerve along the forearm and upper arm. We first performed a description of the fascicular content and branching patterns along the length of the arm. Next we built a 3D reconstruction of the median nerve so we could analyze the fascicle morphological features in relation to the arm level. Finally, we characterized the motor content of the median nerve fascicles in the upper arm. Collectively, these results indicate that fascicular organization occurs in a short segment distal to the epicondyles and remains unaltered until the muscular branches leave the main trunk. Based on our results, overall recommendations based on electrode type and implant location can be drawn to help and aid the neuroprosthetic procedure. Invasive interfaces would be more convenient for the upper arm and the most proximal third of the forearm. Epineural electrodes seem to be most suitable for the forearm segment after fascicles have been divided from the main trunk. PMID:27445660

  1. Fascicular Topography of the Human Median Nerve for Neuroprosthetic Surgery.

    PubMed

    Delgado-Martínez, Ignacio; Badia, Jordi; Pascual-Font, Arán; Rodríguez-Baeza, Alfonso; Navarro, Xavier

    2016-01-01

    One of the most sought-after applications of neuroengineering is the communication between the arm and an artificial prosthetic device for the replacement of an amputated hand or the treatment of peripheral nerve injuries. For that, an electrode is placed around or inside the median nerve to serve as interface for recording and stimulation of nerve signals coming from the fascicles that innervate the muscles responsible for hand movements. Due to the lack of a standard procedure, the electrode implantation by the surgeon is strongly based on intuition, which may result in poor performance of the neuroprosthesis because of the suboptimal location of the neural interface. To provide morphological data that can aid the neuroprosthetic surgeon with this procedure, we investigated the fascicular topography of the human median nerve along the forearm and upper arm. We first performed a description of the fascicular content and branching patterns along the length of the arm. Next we built a 3D reconstruction of the median nerve so we could analyze the fascicle morphological features in relation to the arm level. Finally, we characterized the motor content of the median nerve fascicles in the upper arm. Collectively, these results indicate that fascicular organization occurs in a short segment distal to the epicondyles and remains unaltered until the muscular branches leave the main trunk. Based on our results, overall recommendations based on electrode type and implant location can be drawn to help and aid the neuroprosthetic procedure. Invasive interfaces would be more convenient for the upper arm and the most proximal third of the forearm. Epineural electrodes seem to be most suitable for the forearm segment after fascicles have been divided from the main trunk. PMID:27445660

  2. Tendon Transfers Part II: Transfers for Ulnar Nerve Palsy and Median Nerve Palsy

    PubMed Central

    Sammer, Douglas M.; Chung, Kevin C.

    2009-01-01

    Objectives After reading this article (part II of II), the participant should be able to: 1. Describe the anatomy and function of the median and ulnar nerves in the forearm and hand. 2. Describe the clinical deficits associated with injury to each nerve. 3. Describe the indications, benefits, and drawbacks for various tendon transfer procedures used to treat median and ulnar nerve palsy.4. Describe the treatment of combined nerve injuries. 5. Describe postoperative care and possible complications associated with these tendon transfer procedures. Summary This article discusses the use of tendon transfer procedures for treatment of median and ulnar nerve palsy as well as combined nerve palsies. Postoperative management and potential complications are also discussed. PMID:19730287

  3. Inter-hemispheric plasticity in patients with median nerve injury.

    PubMed

    Fornander, Lotta; Nyman, Torbjörn; Hansson, Thomas; Brismar, Tom; Engström, Maria

    2016-08-15

    Peripheral nerve injuries result in reorganization within the contralateral hemisphere. Furthermore, recent animal and human studies have suggested that the plastic changes in response to peripheral nerve injury also include several areas of the ipsilateral hemisphere. The objective of this study was to map the inter-hemispheric plasticity in response to median nerve injury, to investigate normal differences in contra- and ipsilateral activation, and to study the impact of event-related or blocked functional magnetic resonance imaging (fMRI) design on ipsilateral activation. Four patients with median nerve injury at the wrist (injured and epineurally sutured >2 years earlier) and ten healthy volunteers were included. 3T fMRI was used to map the hemodynamic response to brain activity during tactile stimulation of the fingers, and a laterality index (LI) was calculated. Stimulation of Digits II-III of the injured hand resulted in a reduction in contralateral activation in the somatosensory area SI. Patients had a lower LI (0.21±0.15) compared to healthy controls (0.60±0.26) indicating greater ipsilateral activation of the primary somatosensory cortex. The spatial dispersion of the coordinates for areas SI and SII was larger in the ipsilateral than in the contralateral hemisphere in the healthy controls, and was increased in the contralateral hemisphere of the patients compared to the healthy controls. There was no difference in LI between the event-related and blocked paradigms. In conclusion, patients with median nerve injury have increased ipsilateral SI area activation, and spatially more dispersed contralateral SI activation during tactile stimulation of their injured hand. In normal subjects ipsilateral activation has larger spatial distribution than the contralateral. Previous findings in patients performed with the blocked fMRI paradigm were confirmed. The increase in ipsilateral SI activation may be due to an interhemispheric disinhibition associated with

  4. Morphometric studies of the muscular branch of the median nerve.

    PubMed

    Olave, E; Prates, J C; Gabrielli, C; Pardi, P

    1996-10-01

    The branch from the median nerve to the thenar muscles has a proximal and lateral (recurrent) course and is vulnerable to lesions that affect these muscles. Because of its anatomical-clinical importance, this branch was studied in 60 palmar regions from 30 cadavers of adult individuals of both sexes, aged between 23 and 77 y. It arose from the lateral branch of the median nerve in 83.3% of the cases. Its origin was distal to the flexor retinaculum in 48.3%, at the distal margin of the retinaculum in 31.6%, in the carpal tunnel in 18.3% and proximal to the retinaculum in 1.7%; it pierced the retinaculum in 15%. The point of recurrence of the branch was localised topographically to 34.6 +/- 3.6 mm from the distal wrist crease; the angle between its recurrent course and the longitudinal axis of the hand averaged 66.8 degrees. In 50% of the cases the muscular branch innervated abductor pollicis brevis (APB), opponens pollicis (OP) and the superficial head of flexor pollicis brevis (FPB), in 40% it supplied only APB and OP, and in 10% a short muscular branch gave rise to independent branches in the palm and which supplied APB, OP and the superficial head of FPB. The so called "accessory thenar branch' was found in 38.3%. PMID:8886966

  5. Right Median Nerve Electrical Stimulation for Acute Traumatic Coma Patients.

    PubMed

    Lei, Jin; Wang, Lei; Gao, Guoyi; Cooper, Edwin; Jiang, Jiyao

    2015-10-15

    The right median nerve as a peripheral portal to the central nervous system can be electrically stimulated to help coma arousal after traumatic brain injury (TBI). The present study set out to examine the efficacy and safety of right median nerve electrical stimulation (RMNS) in a cohort of 437 comatose patients after severe TBI from August 2005 to December 2011. The patients were enrolled 2 weeks after their injury and assigned to the RMNS group (n=221) receiving electrical stimulation for 2 weeks or the control group (n = 216) treated by standard management according to the date of birth in the month. The baseline data were similar. After the 2-week treatment, the RMNS-treated patients demonstrated a more rapid increase of the mean Glasgow Coma Score, although statistical significance was not reached (8.43 ± 4.98 vs. 7.47 ± 5.37, p = 0.0532). The follow-up data at 6-month post-injury showed a significantly higher proportion of patients who regained consciousness (59.8% vs. 46.2%, p = 0.0073). There was a lower proportion of vegetative persons in the RMNS group than in the control group (17.6% vs. 22.0%, p = 0.0012). For persons regaining consciousness, the functional independence measurement (FIM) score was higher among the RMNS group patients (91.45 ± 8.65 vs. 76.23 ± 11.02, p < 0.001). There were no unique complications associated with the RMNS treatment. The current study, although with some limitations, showed that RMNS may serve as an easy, effective, and noninvasive technique to promote the recovery of traumatic coma in the early phase. PMID:25664378

  6. Origin of the widespread N18 in median nerve SEP.

    PubMed

    Sonoo, M; Genba, K; Zai, W; Iwata, M; Mannen, T; Kanazawa, I

    1992-01-01

    The widespread N18 potential in median nerve SEP was studied in normal subjects and in patients with high cervical, brain-stem and thalamic lesions who had profound disturbances of deep sensation. N18 was well identified in the HSi-CV2 derivation in every normal subject as a broad elevation from the baseline lasting about 20 msec. The cortical N20 was absent in all patients. N18 was absent in a patient with a dorsal column lesion at C1-2 level. The amplitude and configuration of N18 were normal in all other patients with brain-stem and thalamic lesions, including a patient with a lesion at the ponto-medullary junction. The sagittal distribution of N18 was studied in a patient with a thalamic lesion and an oblique distribution with the maximum region between Cz and nasion was demonstrated. The present results indicate that at least the greater part of N18 is generated at the caudal most brain-stem or through branches from this level. Taking previous animal and intraoperative studies into consideration, we think it most probable that the main part of N18 corresponds to the ventro-rostral negative pole of the dipolar potential generated at the cuneate nucleus by the primary afferent depolarization of presynaptic terminals of dorsal column fibers. PMID:1382950

  7. Assessment of Median Nerve Mobility by Ultrasound Dynamic Imaging for Diagnosing Carpal Tunnel Syndrome

    PubMed Central

    Kuo, Tai-Tzung; Lee, Ming-Ru; Liao, Yin-Yin; Chen, Jiann-Perng; Hsu, Yen-Wei; Yeh, Chih-Kuang

    2016-01-01

    Carpal tunnel syndrome (CTS) is the most common peripheral neuropathy and is characterized by median nerve entrapment at the wrist and the resulting median nerve dysfunction. CTS is diagnosed clinically as the gold standard and confirmed with nerve conduction studies (NCS). Complementing NCS, ultrasound imaging could provide additional anatomical information on pathological and motion changes of the median nerve. The purpose of this study was to estimate the transverse sliding patterns of the median nerve during finger movements by analyzing ultrasound dynamic images to distinguish between normal subjects and CTS patients. Transverse ultrasound images were acquired, and a speckle-tracking algorithm was used to determine the lateral displacements of the median nerve in radial-ulnar plane in B-mode images utilizing the multilevel block-sum pyramid algorithm and averaging. All of the averaged lateral displacements at separate acquisition times within a single flexion–extension cycle were accumulated to obtain the cumulative lateral displacements, which were curve-fitted with a second-order polynomial function. The fitted curve was regarded as the transverse sliding pattern of the median nerve. The R2 value, curvature, and amplitude of the fitted curves were computed to evaluate the goodness, variation and maximum value of the fit, respectively. Box plots, the receiver operating characteristic (ROC) curve, and a fuzzy c-means clustering algorithm were utilized for statistical analysis. The transverse sliding of the median nerve during finger movements was greater and had a steeper fitted curve in the normal subjects than in the patients with mild or severe CTS. The temporal changes in transverse sliding of the median nerve within the carpal tunnel were found to be correlated with the presence of CTS and its severity. The representative transverse sliding patterns of the median nerve during finger movements were demonstrated to be useful for quantitatively estimating

  8. Assessment of Median Nerve Mobility by Ultrasound Dynamic Imaging for Diagnosing Carpal Tunnel Syndrome.

    PubMed

    Kuo, Tai-Tzung; Lee, Ming-Ru; Liao, Yin-Yin; Chen, Jiann-Perng; Hsu, Yen-Wei; Yeh, Chih-Kuang

    2016-01-01

    Carpal tunnel syndrome (CTS) is the most common peripheral neuropathy and is characterized by median nerve entrapment at the wrist and the resulting median nerve dysfunction. CTS is diagnosed clinically as the gold standard and confirmed with nerve conduction studies (NCS). Complementing NCS, ultrasound imaging could provide additional anatomical information on pathological and motion changes of the median nerve. The purpose of this study was to estimate the transverse sliding patterns of the median nerve during finger movements by analyzing ultrasound dynamic images to distinguish between normal subjects and CTS patients. Transverse ultrasound images were acquired, and a speckle-tracking algorithm was used to determine the lateral displacements of the median nerve in radial-ulnar plane in B-mode images utilizing the multilevel block-sum pyramid algorithm and averaging. All of the averaged lateral displacements at separate acquisition times within a single flexion-extension cycle were accumulated to obtain the cumulative lateral displacements, which were curve-fitted with a second-order polynomial function. The fitted curve was regarded as the transverse sliding pattern of the median nerve. The R2 value, curvature, and amplitude of the fitted curves were computed to evaluate the goodness, variation and maximum value of the fit, respectively. Box plots, the receiver operating characteristic (ROC) curve, and a fuzzy c-means clustering algorithm were utilized for statistical analysis. The transverse sliding of the median nerve during finger movements was greater and had a steeper fitted curve in the normal subjects than in the patients with mild or severe CTS. The temporal changes in transverse sliding of the median nerve within the carpal tunnel were found to be correlated with the presence of CTS and its severity. The representative transverse sliding patterns of the median nerve during finger movements were demonstrated to be useful for quantitatively estimating

  9. Personal and workplace factors and median nerve function in a pooled study of 2396 US workers

    PubMed Central

    Rempel, David; Gerr, Fred; Harris-Adamson, Carisa; Hegmann, Kurt T; Thiese, Matthew S.; Kapellusch, Jay; Garg, Arun; Burt, Susan; Bao, Stephen; Silverstein, Barbara; Merlino, Linda; Dale, Ann Marie; Evanoff, Bradley

    2015-01-01

    Objective Evaluate associations between personal and workplace factors and median nerve conduction latency at the wrist. Methods Baseline data on workplace psychosocial and physical exposures were pooled from five prospective studies of production and service workers (N=2396). During the follow-up period, electrophysiologic measures of median nerve function were collected at regular intervals. Results Significant adjusted associations were observed between age, BMI, gender, peak hand force, duration of forceful hand exertions, TLV for HAL, forceful repetition rate, wrist extension, and decision latitude on median nerve latencies. Conclusions Occupational and non-occupational factors have adverse effects on median nerve function. Measuring median nerve function eliminates possible reporting bias that may affect symptom-based carpal tunnel syndrome (CTS) case definitions. These results suggest that previously observed associations between CTS and occupational factors are not the result of such reporting bias. PMID:25563546

  10. Effects of computer keyboarding on ultrasonographic measures of the median nerve

    PubMed Central

    Toosi, KK; Impink, BG; Baker, NA; Boninger, ML

    2011-01-01

    Background Keyboarding is a highly repetitive daily task and has been linked to musculoskeletal disorders of the upper extremity. However, the effect of keyboarding on median nerve injuries is not well understood. The purpose of this study was to use ultrasonographic measurements to determine whether continuous keyboarding can cause acute changes in the median nerve. Methods Ultrasound images of the median nerve from twenty-one volunteers were captured at the levels of the pisiform and distal radius prior to and following a prolonged keyboarding task (i.e., one hour of continuous keyboarding). Images were analyzed by a blinded investigator to quantify the median nerve characteristics. Changes in the median nerve ultrasonographic measures as a result of continuous keyboarding task were evaluated. Results Cross-sectional areas at the pisiform level were significantly larger in both dominant (p=0.004) and non-dominant (p=0.001) hands following the keyboarding task. Swelling ratio was significantly greater in the dominant hand (p=0.020) after 60 minutes of keyboarding when compared to the baseline measures. Flattening ratios were not significantly different in either hand as a result of keyboarding. Conclusion We were able to detect an acute increase in the area of the median nerve following one hour of keyboarding with a computer keyboard. This suggests that keyboarding has an impact on the median nerve. Further studies are required to understand this relationship, which would provide insight into the pathophysiology of median neuropathies such as carpal tunnel syndrome. PMID:21739468

  11. Differential Diagnosis and Intervention of Proximal Median Nerve Entrapment: A Resident's Case Problem.

    PubMed

    Bair, Marcus R; Gross, Michael T; Cooke, Jennifer R; Hill, Carla H

    2016-09-01

    Study Design Resident's case problem. Background Entrapment neuropathies represent a diagnostic challenge and require a comprehensive understanding of the nerve's path and the anatomical structures that may cause compression of the nerve. This resident's case problem details the evaluation and differential diagnosis process for median nerve entrapment resulting from forceful and repetitive pronation/supination motions. Diagnosis Median nerve compression syndromes include pronator syndrome, anterior interosseous nerve syndrome, and carpal tunnel syndrome. A cluster of clinical special tests were performed to determine the anatomical site of median nerve entrapment. Based on the patient's history and clinical test results, a diagnosis of pronator syndrome was determined. Provocation testing specific to pronator syndrome assisted with further localizing the site of entrapment to the pronator teres muscle, which guided effective management strategies. Discussion This resident's case problem illustrates the importance of detailed anatomical knowledge and a differential diagnostic process when evaluating a patient with signs and symptoms of an entrapment neuropathy of the median nerve. Electrodiagnostic studies are useful in ruling out carpal tunnel and anterior interosseous nerve syndromes, but are often inconclusive in cases of pronator syndrome. Therefore, a diagnosis of pronator syndrome in this case problem was based on a detailed understanding of median nerve anatomy, potential sites of compression, and unique clinical features associated with this condition. Level of Evidence Differential diagnosis, level 4. J Orthop Sports Phys Ther 2016;46(9):800-808. Epub 5 Aug 2016. doi:10.2519/jospt.2016.6723. PMID:27494058

  12. Sonographic Appearance of the Median Nerve Following Revision Carpal Tunnel Surgery

    PubMed Central

    Shapiro, Shane A; Alkhamisi, Ashkan; Pujalte, George G A

    2016-01-01

    The main objective of this pictorial essay is to illustrate the sonographic appearance of the postoperative carpal tunnel and median nerve. Carpal tunnel surgical treatment failures have been shown to occur in up to 19% of a large series requiring re-exploration. Surgical management options for recurrent carpal tunnel syndrome (CTS) include revision release, neurolysis, vein wrapping, and fat grafting procedures. While several descriptions of median nerve entrapment in CTS exist in the ultrasound literature, little is written regarding its postoperative appearance. We report the sonographic changes in the appearance of the median nerve and postoperative carpal tunnel. PMID:27195177

  13. Median nerve deformation and displacement in the carpal tunnel during index finger and thumb motion.

    PubMed

    van Doesburg, Margriet H M; Yoshii, Yuichi; Villarraga, Hector R; Henderson, Jacqueline; Cha, Stephen S; An, Kai-Nan; Amadio, Peter C

    2010-10-01

    The purpose of this study was to investigate the deformation and displacement of the normal median nerve in the carpal tunnel during index finger and thumb motion, using ultrasound. Thirty wrists from 15 asymptomatic volunteers were evaluated. Cross-sectional images during motion from full extension to flexion of the index finger and thumb were recorded. On the initial and final frames, the median nerve, flexor pollicis longus (FPL), and index finger flexor digitorum superficialis (FDS) tendons were outlined. Coordinate data were recorded and median nerve cross-sectional area, perimeter, aspect ratio of the minimal-enclosing rectangle, and circularity in extension and flexion positions were calculated. During index finger flexion, the tendon moves volarly while the nerve moves radially. With thumb flexion, the tendon moves volarly, but the median nerve moves toward the ulnar side. In both motions, the area and perimeter of the median nerve in flexion were smaller than in extension. Thus, during index finger or thumb flexion, the median nerve in a healthy human subject shifts away from the index finger FDS and FPL tendons while being compressed between the tendons and the flexor retinaculum in the carpal tunnel. We are planning to compare these data with measurements in patients with carpal tunnel syndrome (CTS) and believe that these parameters may be useful tools for the assessment of CTS and carpal tunnel mechanics with ultrasound in the future. PMID:20225286

  14. Multielectrode nerve cuff stimulation of the median nerve produces selective movements in a raccoon animal model.

    PubMed

    Walter, J S; Griffith, P; Sweeney, J; Scarpine, V; Bidnar, M; McLane, J; Robinson, C

    1997-04-01

    In this study, an electrode system consisting of twelve small platinum dot electrodes imbedded in a spiral silicone rubber insulating cuff was used to investigate the feasibility of selective (regional) stimulation of the median nerves of the raccoon. Acute experiments in four raccoons consisted of functional responses observations, isometric force recordings from tendon attachments and postmortem fascicular mapping. Functional responses (elbow, wrist and/or digit flexion, pronation and/or thumb abduction) to selective stimulation were noted as dependent upon cuff electrode configuration (longitudinal tripole with and without field steering, as well as a transverse bipolar arrangement) and current level (threshold, 1/2 maximal, maximal). Muscle force recruitment curves (force as a function of stimulus amplitude) were plotted for flexor digitorum superficialis, flexor digitorum profundus, flexor carpi radialis, palmaris longus and pronator teres of three raccoons. Fascicular maps at the level of the nerve cuff were created indicating the approximate position of innervation to each of the aforementioned muscles, as well as other innervation such as paw fascicles, sensory fascicles, and elbow innervation (such as coracobrachialis). The greatest selectivity was observed at or near threshold current levels. In all four raccoons studied, a threshold electrode choice and stimulation strategy could be identified enabling selective production of either digit flexion, wrist flexion and/or digit and wrist flexion. It was possible to elicit a selective pronation response at threshold in three of the four animals. Selective elbow flexion at threshold could be produced in all four experiments. With stronger currents, additional movements were usually induced. The raccoon therefore appears to be a suitable, if challenging, animal model for further development of not only nerve cuff electrode approaches but perhaps other stimulation electrode technologies prior to human

  15. Development of Kinematic Graphs of Median Nerve during Active Finger Motion: Implications of Smartphone Use

    PubMed Central

    2016-01-01

    Background Certain hand activities cause deformation and displacement of the median nerve at the carpal tunnel due to the gliding motion of tendons surrounding it. As smartphone usage escalates, this raises the public’s concern whether hand activities while using smartphones can lead to median nerve problems. Objective The aims of this study were to 1) develop kinematic graphs and 2) investigate the associated deformation and rotational information of median nerve in the carpal tunnel during hand activities. Methods Dominant wrists of 30 young adults were examined with ultrasonography by placing a transducer transversely on their wrist crease. Ultrasound video clips were recorded when the subject performing 1) thumb opposition with the wrist in neutral position, 2) thumb opposition with the wrist in ulnar deviation and 3) pinch grip with the wrist in neutral position. Six still images that were separated by 0.2-second intervals were then captured from the ultrasound video for the determination of 1) cross-sectional area (CSA), 2) flattening ratio (FR), 3) rotational displacement (RD) and 4) translational displacement (TD) of median nerve in the carpal tunnel, and these collected information of deformation, rotational and displacement of median nerve were compared between 1) two successive time points during a single hand activity and 2) different hand motions at the same time point. Finally, kinematic graphs were constructed to demonstrate the mobility of median nerve during different hand activities. Results Performing different hand activities during this study led to a gradual reduction in CSA of the median nerve, with thumb opposition together with the wrist in ulnar deviation causing the greatest extent of deformation of the median nerve. Thumb opposition with the wrist in ulnar deviation also led to the largest extent of TD when compared to the other two hand activities of this study. Kinematic graphs showed that the motion pathways of median nerve during

  16. Ultrasonographic reference sizes of the median and ulnar nerves and the cervical nerve roots in healthy Japanese adults.

    PubMed

    Sugimoto, Takamichi; Ochi, Kazuhide; Hosomi, Naohisa; Mukai, Tomoya; Ueno, Hiroki; Takahashi, Tetsuya; Ohtsuki, Toshiho; Kohriyama, Tatsuo; Matsumoto, Masayasu

    2013-09-01

    The objective of this study was to identify, for practical use, ultrasonographic reference values for nerve sizes at multiple sites, including entrapment and non-entrapment sites along the median and ulnar nerves and among the cervical nerve roots. We verified reliable sites and site-based differences between the reference values. In addition, we found associations between the reference nerve sizes and several physical characteristics (gender, dominant hand, age, height, weight, body mass index [BMI] and wrist circumference). Nerves were measured bilaterally at 26 sites or levels in 60 healthy Japanese adults (29 males; age, 35.4 ± 9.7 y; BMI, 22.3 ± 3.6 kg/m(2); wrist circumference, 16.0 ± 1.3 cm on the right side and 15.9 ± 1.2 cm on the left side). The mean reference nerve sizes were 5.6-9.1 mm(2) along the median nerve, 4.1-6.7 mm(2) along the ulnar nerve and 2.14-3.39 mm among the cervical nerve roots. Multifactorial regression analyses revealed that the physical characteristics most strongly associated with nerve size were age, BMI and wrist circumference at the entrapment sites (F = 7.6, p < 0.01, at the pisiform bone level of the carpal tunnel; F = 15.1, p < 0.001, at the level of Guyon's canal), as well as wrist circumference and gender at the non-entrapment sites (F = 70.6, p < 0.001, along the median nerve; F = 24.7, p < 0.001, along the ulnar nerve). Our results suggest that the factors with the greatest influence on nerve size differed between entrapment and non-entrapment sites. Site-based differences in nerve size were determined using one-way analyses of variance (p < 0.001). Intra- and inter-observer reliability was highest for the median nerve, at both the distal wrist crease and mid-humerus; at the arterial split along the ulnar nerve; and at the fifth cervical nerve root level. No systematic error was indicated by Bland-Altman analysis; the coefficients of variation were 5.5%-9.2% for intra-observer reliability and 7.1%-8.7% for inter

  17. Sleep Deprivation Aggravates Median Nerve Injury-Induced Neuropathic Pain and Enhances Microglial Activation by Suppressing Melatonin Secretion

    PubMed Central

    Huang, Chun-Ta; Chiang, Rayleigh Ping-Ying; Chen, Chih-Li; Tsai, Yi-Ju

    2014-01-01

    Study Objectives: Sleep deprivation is common in patients with neuropathic pain, but the effect of sleep deprivation on pathological pain remains uncertain. This study investigated whether sleep deprivation aggravates neuropathic symptoms and enhances microglial activation in the cuneate nucleus (CN) in a median nerve chronic constriction injury (CCI) model. Also, we assessed if melatonin supplements during the sleep deprived period attenuates these effects. Design: Rats were subjected to sleep deprivation for 3 days by the disc-on-water method either before or after CCI. In the melatonin treatment group, CCI rats received melatonin supplements at doses of 37.5, 75, 150, or 300 mg/kg during sleep deprivation. Melatonin was administered at 23:00 once a day. Participants: Male Sprague-Dawley rats, weighing 180-250 g (n = 190), were used. Measurements: Seven days after CCI, behavioral testing was conducted, and immunohistochemistry, immunoblotting, and enzyme-linked immunosorbent assay were used for qualitative and quantitative analyses of microglial activation and measurements of proinflammatory cytokines. Results: In rats who underwent post-CCI sleep deprivation, microglia were more profoundly activated and neuropathic pain was worse than those receiving pre-CCI sleep deprivation. During the sleep deprived period, serum melatonin levels were low over the 24-h period. Administration of melatonin to CCI rats with sleep deprivation significantly attenuated activation of microglia and development of neuropathic pain, and markedly decreased concentrations of proinflammatory cytokines. Conclusions: Sleep deprivation makes rats more vulnerable to nerve injury-induced neuropathic pain, probably because of associated lower melatonin levels. Melatonin supplements to restore a circadian variation in melatonin concentrations during the sleep deprived period could alleviate nerve injury-induced behavioral hypersensitivity. Citation: Huang CT, Chiang RP, Chen CL, Tsai YJ. Sleep

  18. Use of adjunctive palmaris longus abductorplasty (Camitz) tendon transfer in pediatric median nerve injury.

    PubMed

    Baluch, Narges; Borschel, Gregory H

    2013-05-01

    A number of tendon transfers have been described for opponensplasty. Transfer of the palmaris longus (PL) tendon with a palmar fascial extension was initially described by Camitz. This technique has mostly been combined with carpal tunnel release in patients with long standing median neuropathy with atrophy of the thenar muscles. However, the Camitz transfer has not been previously described in the setting of pediatric median nerve injury. We report 4 cases of Camitz transfer in pediatric patients with median nerve injuries. Four children (all female; age range 3-15 yrs) underwent PL tendon transfer following median nerve injury. The causes of injury included trauma, iatrogenic injury, and neuritis of the brachial plexus. The Camitz procedure was performed at the time of median nerve decompression and/or reconstruction. All patients had excellent early return of function. Transfer of the palmaris longus tendon reliably restores palmar abduction, with minimal to no additional morbidity, in carefully selected pediatric patients with median nerve injury undergoing release of the carpal tunnel. PMID:22981385

  19. Biomechanics of the Median Nerve During Stretching as Assessed by Ultrasonography.

    PubMed

    Martínez-Payá, Jacinto Javier; Ríos-Díaz, José; Del Baño-Aledo, María Elena; García-Martínez, David; de Groot-Ferrando, Ana; Meroño-Gallut, Javier

    2015-12-01

    The objective of this observational cross-sectional study was to investigate the normal motion of the median nerve when stretched during a neurodynamic exercise. In recent years, ultrasonography has been increasingly accepted as an imaging technique for examining peripheral nerves in vivo, offering a reliable and noninvasive method for a precise evaluation of nerve movement. Transverse motion of the median nerve in the arm during a neurodynamic test was measured. A volunteer sample of 22 healthy subjects (11 women) participated in the study. Nerve displacement and deformation were assessed by dynamic ultrasonography. Excellent interobserver agreement was obtained, with kappa coefficient of .7-.8. Ultrasonography showed no lateral motion during wrist extension in 68% of nerves, while 73% moved dorsally, with statistically significant differences between sexes (ORlat = 6.3; 95% CI = 1.4-27.7 and ORdor = 8.3; 95% CI = 1.6-44.6). The cross-sectional area was significantly greater in men (3.6 mm2). Quantitative analysis revealed no other statistically significant differences. Our results provide evidence of substantial individual differences in median nerve transverse displacement in response to a neurodynamic exercise. PMID:26213988

  20. Median and ulnar nerve conduction determinations in the Erb's point--axilla segment in normal subjects.

    PubMed Central

    Ginzburg, M; Lee, M; Ginzburg, J; Alba, A

    1978-01-01

    Twenty-one median and 22 ulnar nerves were tested in 12 patients for motor nerve conduction velocity (MNCV) and motor nerve conduction time (MNCT) in the segments from Erb's point (N) to axilla (A) bilaterally. It was found that on this segment for both nerves, MNCV values equal to or smaller than 51 m/s or conduction times equal to or longer than 4 ms are to be considered abnormal. For comparative studies and for checking the normality of the tested nerves in their entire length, the more distally located segments in the same nerve were also tested. For diagnostic purposes, the differences between right and left MNCV or MNCT values determined in the same person on N-A segments of homologous nerves were analysed. Motor nerve conduction velocity or MNCT determinations on the N-A nerve segment are expected to replace MNCV determinations on the longer N-AE (AE=100 mm above elbow) nerve segment, which is now in use, for diagnosis of the thoracic outlet syndrome. Images PMID:660207

  1. Importance of Tissue Morphology Relative to Patient Reports of Symptoms and Functional Limitations Resulting From Median Nerve Pathology

    PubMed Central

    Evans, Kevin D.; Li, Xiaobai; Sommerich, Carolyn M.; Case-Smith, Jane

    2013-01-01

    Significant data exist for the personal, environmental, and occupational risk factors for carpal tunnel syndrome. Few data, however, explain the interrelationship of tissue morphology to these factors among patients with clinical presentation of median nerve pathology. Therefore, our primary objective was to examine the relationship of various risk factors that may be predictive of subjective reports of symptoms or functional deficits accounting for median nerve morphology. Using diagnostic ultrasonography, we observed real-time median nerve morphology among 88 participants with varying reports of symptoms or functional limitations resulting from median nerve pathology. Body mass index, educational level, and nerve morphology were the primary predictive factors. Monitoring median nerve morphology with ultrasonography may provide valuable information for clinicians treating patients with symptoms of median nerve pathology. Sonographic measurements may be a useful clinical tool for improving treatment planning and provision, documenting patient status, or measuring clinical outcomes of prevention and rehabilitation interventions. PMID:23245784

  2. A wakeboarding injury presented as acute carpal syndrome and median nerve contusion after wrist strangulation: a case report

    PubMed Central

    2009-01-01

    Background We present a case of combined median nerve contusion with immediate loss of sensation after the strangulation with a wakeboarding rope and prolonged referral to our department 72 hours after the injury accompanied by an acute carpal tunnel syndrome with immediate relief of numbness of a significant proportion of the median nerve following surgical decompression. Case presentation The palmar branch of the median nerve was surrounded by a significant haematoma in addition to the strangulation damage caused by its more superficial location in contrast to the median nerve. Conclusion In case of acute median neuropathy, urgent surgical intervention with exploration, decompression of both, the median nerve and the superficial branch of the median nerve, accompanied by compartment measurements of the forearm should be performed to regain or re-establish neurological integrity. PMID:19178709

  3. Morphological and positional changes of the carpal arch and median nerve during wrist compression

    PubMed Central

    Marquardt, Tamara L.; Gabra, Joseph N.; Li, Zong-Ming

    2015-01-01

    Background The carpal tunnel is a fibro-osseous structure containing the median nerve and flexor tendons. Its cross-sectional area has been shown to increase during compressive force application to the carpal bones in modeling and in vitro studies. The purpose of this study was to investigate the morphological and positional changes of the carpal arch and median nerve while in vivo compressive force was applied in the radioulnar direction across the wrist. Methods Ultrasound images of the carpal tunnel and its contents were captured for 11 healthy, female volunteers at the distal tunnel level prior to force application and during force application of 10 and 20 N. Findings With applied force, the carpal arch width significantly decreased, while the carpal arch height and area significantly increased (P < 0.001). The median nerve shape became more rounded as the compressive force magnitude increased, reflected by decreases in the nerve’s flattening ratio and increases in its circularity (P < 0.001). The applied force also resulted in nerve displacement in the radial-volar direction. Interpretation This study demonstrates that noninvasively applying radioulnar compressive force across the wrist may potentially provide relief of median nerve compression to patients suffering from carpal tunnel syndrome. PMID:25661267

  4. The usefulness of terminal latency index of median nerve and f-wave difference between median and ulnar nerves in assessing the severity of carpal tunnel syndrome.

    PubMed

    Park, Kang Min; Shin, Kyong Jin; Park, Jinse; Ha, Sam Yeol; Kim, Sung Eun

    2014-04-01

    The calculated electrophysiological parameters, such as terminal latency index (TLI), residual latency, modified F ratio, and F-wave inversion, have been investigated as a diagnostic tool for detection of early stage of carpal tunnel syndrome (CTS) in the literature. However, the correlation of these calculated electrophysiological parameters with the clinical severity of CTS has not been reported. The aim of this study was to determine the correlation of the calculated electrophysiological parameters and clinical severity in patients with CTS. A retrospective study was performed with 212 hands of 106 CTS patients. The CTS hands were classified as asymptomatic, mild, moderate, and severe according to the clinical severity. The distal motor latency and distal motor conduction velocity of median nerve, minimal F-wave latency of median and ulnar nerves, and sensory nerve conduction velocity in the finger-wrist and palm-wrist segment of median nerve (SNCV f-w and SNCV p-w) were obtained in a conventional nerve conduction study. The TLI, residual latency, and modified F ratio of the median nerve and the difference of minimal F-wave latencies between the median and ulnar nerves (F-diff M-U) were calculated. The distal motor latency, residual latency, and F-diff M-U were significantly increased according to the clinical severity of CTS. The motor conduction velocity, SNCV p-w, SNCV f-w, TLI, and modified F ratio were significantly decreased according to the clinical severity of CTS. In analyses of variance and Kruskal-Wallis test, we used the Scheffe test as a post-hoc comparison analysis. The TLI, F-diff M-U, and SNCV f-w showed a significant difference among all groups of each CTS severity. The sensitivity, specificity, and cut-off value of TLI, F-diff M-U, and SNCV f-w between asymptomatic and mild, mild and moderate, and moderate and severe CTS groups were calculated by using receiver operating characteristic curve analysis. The cut-off values of TLI, F-diff M-U, and

  5. Effect of Wrist Angle on Median Nerve Appearance at the Proximal Carpal Tunnel

    PubMed Central

    Loh, Ping Yeap; Muraki, Satoshi

    2015-01-01

    This study investigated the effects of wrist angle, sex, and handedness on the changes in the median nerve cross-sectional area (MNCSA) and median nerve diameters, namely longitudinal diameter (D1) and vertical diameter (D2). Ultrasound examination was conducted to examine the median nerve at the proximal carpal tunnel in both dominant and nondominant hands of men (n = 27) and women (n = 26). A total of seven wrist angles were examined: neutral; 15°, 30°, and 45° extension; and 15°, 30°, and 45° flexion. Our results indicated sexual dimorphism and bilateral asymmetry of MNCSA, D1 and D2 measurements. MNCSA was significantly reduced when the wrist angle changed from neutral to flexion or extension positions. At flexion positions, D1 was significantly smaller than that at neutral. In contrast, at extension positions, D2 was significantly smaller than that at neutral. In conclusion, this study showed that MNCSA decreased as the wrist angle changed from neutral to flexion or extension positions in both dominant and nondominant hands of both sexes, whereas deformation of the median nerve differed between wrist flexion and extension. PMID:25658422

  6. Isolated Fascial Compression of the Recurrent Motor Branch of the Median Nerve: A Case Report

    PubMed Central

    2006-01-01

    Isolated compression of the recurrent motor branch (RMB) of the median nerve is not commonly reported. This report deals with a case of fascial band compression of the RMB of the median nerve with sparing of the sensory portion of the nerve in a single patient. The episode was precipitated by the subject was clearing fallen trees after an ice storm. Symptoms occurred only in the left, nondominant hand of the patient, a 43-year-old invasive cardiologist. He presented within weeks of symptom onset, but marked clinical and electrodiagnostic abnormalities of the branch were already present. Timely decompression after evaluation led to a successful clinical outcome, with restoration of full strength on manual muscle testing by 6 months postoperatively and marked electrodiagnostic improvements as well by 11 months after operation. Final clinical examination 16 months after operation showed thenar muscle bulk and strength well maintained. PMID:18780034

  7. Cold intolerance following median and ulnar nerve injuries: prognosis and predictors.

    PubMed

    Ruijs, A C J; Jaquet, J-B; van Riel, W G; Daanen, H A M; Hovius, S E R

    2007-08-01

    This study describes the predictors for cold intolerance and the relationship to sensory recovery after median and ulnar nerve injuries. The study population consisted of 107 patients 2 to 10 years after median, ulnar or combined median and ulnar nerve injuries. Patients were asked to fill out the Cold Intolerance Severity Score (CISS) questionnaire and sensory recovery was measured using Semmes-Weinstein monofilaments. Fifty-six percent of the patients with a single nerve injury and 70% with a combined nerve injury suffered abnormal cold intolerance. Patients with no return of sensation had dramatically higher CISS-scores than patients with normal sensory recovery. Females had higher CISS scores post-injury than males. Cold intolerance did not diminish over the years. Patients with higher CISS scores needed more time to return to their work. Age, additional arterial injury, site or type of the injury and dominance of the hand were not found to have a significant influence on cold intolerance. PMID:17482322

  8. Carpal arch and median nerve changes during radioulnar wrist compression in carpal tunnel syndrome patients.

    PubMed

    Marquardt, Tamara L; Evans, Peter J; Seitz, William H; Li, Zong-Ming

    2016-07-01

    The purpose of this study was to investigate the morphological changes of the carpal arch and median nerve during the application of radiounlarly directed compressive force across the wrist in patients with carpal tunnel syndrome. Radioulnar compressive forces of 10 N and 20 N were applied at the distal level of the carpal tunnel in 10 female patients diagnosed with carpal tunnel syndrome. Immediately prior to force application and after 3 min of application, ultrasound images of the distal carpal tunnel were obtained. It was found that applying force across the wrist decreased the carpal arch width (p < 0.001) and resulted in increased carpal arch height (p < 0.01), increased carpal arch curvature (p < 0.001), and increased radial distribution of the carpal arch area (p < 0.05). It was also shown that wrist compression reduced the flattening of the median nerve, as indicated by changes in the nerve's circularity and flattening ratio (p < 0.001). This study demonstrated that the carpal arch can be non-invasively augmented by applying compressive force across the wrist, and that this strategy may decompress the median nerve providing symptom relief to patients with carpal tunnel syndrome. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:1234-1240, 2016. PMID:26662276

  9. Post-traumatic Median Nerve Neuroma in Wrist. A Case Report and brief review of Literature

    PubMed Central

    Aslan, Ahmet; Konya, Mehmet Nuri; Sargin, Serdar

    2013-01-01

    Introduction: Distal median nerve masses may be developed post-traumatic or non-traumatic. In this paper, we aim to present a 52 year old female case with a postraumatic neuroma of the median nerve in the left wrist. Case Series: A 52-year-old female patient had accidental incised wound over her left wrist which was primarily sutured. She presented 6 months later with unrelieved pain and growing swelling at the wrist. USG showed solid mass of size 2x3 cms. Intraoperatively the mass was seen to arise from medial nerve and careful excision was done protecting the nerve. At one year follow up the patient is relived of her symptoms with no sensorimotor deficit. Conclusion: Post traumatic neuroma present as unrelieved pain and progressive swelling. A high index of suspicion should be kept in cases of wound that are primarily sutured over an area with superficial nerves. Careful excision of the lesion is very effective in relieving patients symptoms PMID:27298917

  10. Median Nerve Injury following K-wire Fixation of Bennett’s Fracture—Lessons Learned

    PubMed Central

    Shetty, Sanath K.; Hanna, Amir W.

    2010-01-01

    Bennett's fracture is a relatively common injury. The fracture is unstable due to the displacing forces acting on the distal fragment and very commonly treated by stabilization with Kirschner wires. This would seem a relatively safe procedure, and injury to the median nerve has never been reported. We present this unusual complication following one such procedure with the evaluation of a safe approach utilizing the relevant surgical and radiological anatomy. PMID:22131930

  11. Pigmented villonodular synovitis of the elbow with rdial, median and ulnar nerve compression

    PubMed Central

    Lu, Hui; Chen, Qiang; Shen, Hui

    2015-01-01

    Pigmented villonodular synovitis (PVNS) is a rare, idiopathic proliferative disorder of the synovium. While, PVNS of elbow is extremely rare. We report an 82-year-old female patient with 20-year-history of gradually increased PVNS in her left elbow. The multiple masses were located in anterior, medial and lateral of elbow. Her radial, median and ulnar nerves were compressed by the tumor. We resected tumor of extra-articular part piecemeally and released the compression of nerves. After the surgery, the patient gained a functional recovery. Two years after surgery she had a tumor recurrence, but without any symptoms of nerve compression syndromes. We discussed its clinical diagnosis, radiological features, MRI findings, pathophysiology, and treatment. PMID:26823718

  12. Carpal arch and median nerve changes during radioulnar wrist compression in carpal tunnel syndrome patients

    PubMed Central

    Marquardt, Tamara L.; Evans, Peter J.; Seitz, William H.; Li, Zong-Ming

    2015-01-01

    The purpose of this study was to investigate the morphological changes of the carpal arch and median nerve during the application of radiounlarly directed compressive force across the wrist in patients with carpal tunnel syndrome. Radioulnar compressive forces of 10 N and 20 N were applied at the distal level of the carpal tunnel in 10 female patients diagnosed with carpal tunnel syndrome. Immediately prior to force application and after 3 minutes of application, ultrasound images of the distal carpal tunnel were obtained. It was found that applying force across the wrist decreased the carpal arch width (p < 0.001) and resulted in increased carpal arch height (p < 0.01), increased carpal arch curvature (p < 0.001), and increased radial distribution of the carpal arch area (p < 0.05). It was also shown that wrist compression reduced the flattening of the median nerve, as indicated by changes in the nerve’s circularity and flattening ratio (p < 0.001). Statement of clinical significance This study demonstrated that the carpal arch can be non-invasively augmented by applying compressive force across the wrist, and that this strategy may decompress the median nerve providing symptom relief to patients with carpal tunnel syndrome. PMID:26662276

  13. Enhancement of median nerve regeneration by mesenchymal stem cells engraftment in an absorbable conduit: improvement of peripheral nerve morphology with enlargement of somatosensory cortical representation

    PubMed Central

    Oliveira, Julia T.; Bittencourt-Navarrete, Ruben Ernesto; de Almeida, Fernanda M.; Tonda-Turo, Chiara; Martinez, Ana Maria B.; Franca, João G.

    2014-01-01

    We studied the morphology and the cortical representation of the median nerve (MN), 10 weeks after a transection immediately followed by treatment with tubulization using a polycaprolactone (PCL) conduit with or without bone marrow-derived mesenchymal stem cell (MSC) transplant. In order to characterize the cutaneous representation of MN inputs in primary somatosensory cortex (S1), electrophysiological cortical mapping of the somatosensory representation of the forepaw and adjacent body parts was performed after acute lesion of all brachial plexus nerves, except for the MN. This was performed in ten adult male Wistar rats randomly assigned in three groups: MN Intact (n = 4), PCL-Only (n = 3), and PCL+MSC (n = 3). Ten weeks before mapping procedures in animals from PCL-Only and PCL+MSC groups, animal were subjected to MN transection with removal of a 4-mm-long segment, immediately followed by suturing a PCL conduit to the nerve stumps with (PCL+MSC group) or without (PCL-Only group) injection of MSC into the conduit. After mapping the representation of the MN in S1, animals had a segment of the regenerated nerve processed for light and transmission electron microscopy. For histomorphometric analysis of the nerve segment, sample size was increased to five animals per experimental group. The PCL+MSC group presented a higher number of myelinated fibers and a larger cortical representation of MN inputs in S1 (3,383 ± 390 fibers; 2.3 mm2, respectively) than the PCL-Only group (2,226 ± 575 fibers; 1.6 mm2). In conclusion, MSC-based therapy associated with PCL conduits can improve MN regeneration. This treatment seems to rescue the nerve representation in S1, thus minimizing the stabilization of new representations of adjacent body parts in regions previously responsive to the MN. PMID:25360086

  14. Microneurography in relation to intraneural topography: somatotopic organisation of median nerve fascicles in humans.

    PubMed Central

    Hallin, R G

    1990-01-01

    Microneurography was performed in median nerve sensory fascicles with concentric needle electrodes and with conventional tungsten microneedles. The latter electrodes preferentially recorded activity from the myelinated fibres in the whole fascicle. By contrast, due to its special design, a concentric needle can record activity selectively from even a small part of a fascicle. High amplitude signals in C fibres can be discriminated close to Schwann cells that envelope unmyelinated axons. Apart from being biased for activity in thin fibres, the concentric needles can also record signals from nearby myelinated fibres. The palmar receptive fields of such fibre groups were not congruent with the areas traditionally attributed to multiunit skin afferents in humans, namely the innervation zone(s) of one or two adjacent digital nerve(s). Instead, the multiunit fields often comprised small parts of a digital nerve innervation area, frequently only the pulp of a finger. Single units were always localised within previously screened multiunit areas. Contrary to some previously accepted tenets it is probable that single unit activity in myelinated fibres in these studies is recorded extra-axonally near to a node of Ranvier. The findings also suggest the presence of a somatotopy in human limb nerve fascicles, comparable to that previously established in the spinal cord and the somatosensory cortex. Images PMID:2246655

  15. Median ulnar nerves communication in the forearm: a study with autopsy material.

    PubMed

    Ballesteros, Luis E; Forero, Pedro L; Quintero, Iván D

    2014-01-01

    The incidence of median-ulnar communication in the forearm presents variability in different population groups. The aim of this study was to determine the incidence and morphologic expression of the median-ulnar communication in a sample of the Colombian population. One hundred and eight forearms of autopsy material at the National Institute of Forensic Medicine of Bucaramanga, Colombia were studied. Using an approach of the flexor compartment of forearm the median and ulnar nerves were dissected and the communications between these two structures were characterized. The communicating branch occurred in 28 (25.9%) forearms. It occurred unilaterally in 12 specimens and bilaterally in 8, with statistically significant difference (P=0.01). The communication between the anterior interosseous and ulnar nerves was most frequent, observed in 13 (46.4%) forearms. The length of the communicating branch was 56.9 +/- 8.3 mm. The distance of the proximal and distal points of the communicating branch to the bi- epicondylar line was 59.6 +/- 15.4 mm and 102.7 +/- 23.5 mm respectively. The length of the forearm was 269.8 +/- 15.9 mm. A projection of the communicating branch from the upper third to the midthird of the forearm was observed. The incidence of the median-ulnar communication in the present study is in the high rank reported in the literature; there is an agreement with prior studies in finding more numerous communicating branches in the right forearm. The median-ulnar communication should be taken into account for surgical approach of the forearm. PMID:26749683

  16. Median Nerve Somatosensory Evoked Potential in HTLV-I Associated Myelopathy

    PubMed Central

    Boostani, Reza; Poorzahed, Ali; Ahmadi, Zahra; Mellat, Ali

    2016-01-01

    Introduction HTLV-I Associated Myelopathy/Tropical Spastic Paraparesis (HAM/TSP) is a progressive Myelopathy that mainly involves the corticospinal tract. Despite pronounced involvement of the lower limbs, patients also have abnormalities in their upper limbs. So, we studied somatosensory-evoked potentials (SSEPs) of the median nerve in HAM/TSP patients to determine the extent of the involvement of the pathway of the central nervous system, especially the cervical spinal cord. Methods In this cross sectional study, 48 patients with HAM/TSP who were referred to Qaem Hospital in Mashhad from October 2010 to October 2011 were evaluated for various indices, including SSEPs of the median nerve for N9, N11, N13, and N20 waveforms and also N11–13 and N13–20 Inter Peak Latency (IPL), severity of disease (based on Osama criteria), disease duration (less or more than 2 years), age, and gender. SPSS software was used for data analysis. The t-test was used for quantitative data, and the chi-squared test was used for the qualitative variables. Results Thirty-four patients (70.2%) were females. The mean age was 45.6 ± 14.2 years. About SSEPs indices of the median nerve, N9 and N11 were normal in all patients, but N13 (50%), N20 (16.7%), IPL11–13 (58.3%), and IPL13–20 (22.9%) were abnormal. No significant relationships were found between age, gender, disease duration, and SSEPs indices (p > 0.05), but IPL11–13 and IPL13–20 had significant relationships with disease disability (p = 0.017 and p = 0.01, respectively). Conclusion Despite the lack of obvious complaints of upper limbs, SSEPs indices of the median nerve from the cervical spinal cord to the cortex were abnormal, which indicated extension of the lesion from the thoracic spinal cord up to the cervical spinal cord and thalamocortical pathways. Also, abnormalities in the cervical spinal cord had a direct correlation with the severity of disability in patients with HAM/TSP. PMID:27382445

  17. Pressure Monitoring of Intraneural an Perineural Injections Into the Median, Radial, and Ulnar Nerves; Lessons From a Cadaveric Study

    PubMed Central

    Krol, Andrzej; Szarko, Matthew; Vala, Arber; De Andres, Jose

    2015-01-01

    Background: Nerve damage after regional anesthesia has been of great concern to anesthetists. Various modalities have been suggested to recognize and prevent its incidence. An understudied area is the measurement of intraneural pressure during peripheral nerve blockade. Previous investigations have produced contradicting results with only one study being conducted on human cadavers. Objectives: The purpose of this investigation was to systematically record intraneural and perineural injection pressures on the median, ulnar, and radial nerves exclusively as a primary outcome. Materials and Methods: Ultrasonography-guided injections of 1 mL of 0.9% NaCl over ten seconds were performed on phenol glycerine embalmed cadaveric median, ulnar, and radial nerves. A total of 60 injections were performed, 30 intraneural and 30 perineural injections. The injections pressure was measured using a controlled disc stimulation device. Anatomic dissection was used to confirm needle placement. Results: Intraneural needle placement produced significantly greater pressures than perineural injections did. The mean generated pressures in median, radial, and ulnar nerves were respectively 29.4 ± 9.3, 27.3 ± 8.5, and 17.9 ± 7.0 pound per square inch (psi) (1 psi = 51.7 mmHg) for the intraneural injections and respectively 7.2 ± 2.5, 8.3 ± 2.5, and 6.7 ± 1.8 psi for perineural injections. Additionally the intraneural injection pressures of the ulnar nerve were lower than those of the median and radial nerves. Conclusions: Obtained results demonstrate significant differences between intraneural and perineural injection pressures in the median, ulnar, and radial nerves. Intraneural injection pressures show low specificity but high sensitivity suggesting that pressure monitoring might be a valuable tool in improving the safety and efficacy of peripheral nerve blockade in regional anesthesia. Peripheral nerves “pressure mapping” hypothetically might show difference amongst various

  18. Acute effects of neural mobilization and infrared on the mechanics of the median nerve

    PubMed Central

    Nunes, Monara Kedma; Fontenele dos Santos, Gabrielly; Martins e Silva, Diandra Caroline; Mota de Freitas, Ana Cláudia; Henriques, Isadora Ferreira; Andrade, Peterson Marco; Machado, Dionis de Castro; Teixeira, Silmar; Neves, Marco Orsini; Dias, Gildário; Silva-Júnior, Fernando; Bastos, Victor Hugo

    2016-01-01

    [Purpose] This study analyzed the acute effects of infrared and neural mobilization on the median nerve on the range of elbow extension of the dominant limb. [Subjects and Methods] Forty participants from university, neurologically asymptomatic, 12 males and 28 females (22.8 ± 1.9 years), were randomly divided into four groups: Group 1 (control) rested for 25 minutes in the supine position; Group 2 received the specific neural mobilization for the median nerve; Group 3 received an application of infrared for 15 minutes on the forearm; Group 4 received the same application of infrared followed by neural mobilization. The goniometric parameters of elbow extension were evaluated after the intervention. [Results] Significant differences of extension value were observed between Group 1 and Group 3 (15.75 degrees), and between Group 1 and Group 4 (14.60 degrees), and the average higher in Group 3 (26.35 degrees). [Conclusion] This research provides new experimental evidence that NM in relation to superficial heat produces an immediate effect on elbow range of motion versus NM isolated. PMID:27390402

  19. Acute effects of neural mobilization and infrared on the mechanics of the median nerve.

    PubMed

    Nunes, Monara Kedma; Fontenele Dos Santos, Gabrielly; Martins E Silva, Diandra Caroline; Mota de Freitas, Ana Cláudia; Henriques, Isadora Ferreira; Andrade, Peterson Marco; Machado, Dionis de Castro; Teixeira, Silmar; Neves, Marco Orsini; Dias, Gildário; Silva-Júnior, Fernando; Bastos, Victor Hugo

    2016-06-01

    [Purpose] This study analyzed the acute effects of infrared and neural mobilization on the median nerve on the range of elbow extension of the dominant limb. [Subjects and Methods] Forty participants from university, neurologically asymptomatic, 12 males and 28 females (22.8 ± 1.9 years), were randomly divided into four groups: Group 1 (control) rested for 25 minutes in the supine position; Group 2 received the specific neural mobilization for the median nerve; Group 3 received an application of infrared for 15 minutes on the forearm; Group 4 received the same application of infrared followed by neural mobilization. The goniometric parameters of elbow extension were evaluated after the intervention. [Results] Significant differences of extension value were observed between Group 1 and Group 3 (15.75 degrees), and between Group 1 and Group 4 (14.60 degrees), and the average higher in Group 3 (26.35 degrees). [Conclusion] This research provides new experimental evidence that NM in relation to superficial heat produces an immediate effect on elbow range of motion versus NM isolated. PMID:27390402

  20. Dipole source analyses of early median nerve SEP components obtained from subdural grid recordings.

    PubMed

    Baumgärtner, Ulf; Vogel, Hagen; Ohara, Shinji; Treede, Rolf-Detlef; Lenz, Fred A

    2010-12-01

    The median nerve N20 and P22 SEP components constitute the initial response of the primary somatosensory cortex to somatosensory stimulation of the upper extremity. Knowledge of the underlying generators is important both for basic understanding of the initial sequence of cortical activation and to identify landmarks for eloquent areas to spare in resection planning of cortex in epilepsy surgery. We now set out to localize the N20 and P22 using subdural grid recording with special emphasis on the question of the origin of P22: Brodmann area 4 versus area 1. Electroencephalographic dipole source analysis of the N20 and P22 responses obtained from subdural grids over the primary somatosensory cortex after median nerve stimulation was performed in four patients undergoing epilepsy surgery. Based on anatomical landmarks, equivalent current dipoles of N20 and P22 were localized posterior to (n = 2) or on the central sulcus (n = 2). In three patients, the P22 dipole was located posterior to the N20 dipole, whereas in one patient, the P22 dipole was located on the same coordinate in anterior-posterior direction. On average, P22 sources were found to be 6.6 mm posterior [and 1 mm more superficial] compared with the N20 sources. These data strongly suggest a postcentral origin of the P22 SEP component in Brodmann area 1 and render a major precentral contribution to the earliest stages of processing from the primary motor cortex less likely. PMID:20861430

  1. Mechanosensitivity of the median nerve in patients with chronic carpal tunnel syndrome.

    PubMed

    Jaberzadeh, Shapour; Zoghi, Maryam

    2013-04-01

    The aim was to investigate the relationship between the effects of median nerve strain during the elbow extension component of the upper limb neurodynamic test 1 (ULNT1) and the evoked musculoskeletal changes. 11 patients with chronic carpal tunnel syndrome (CTS) and 11 matched asymptomatic controls participated in the study. In all subjects, elbow extension was carried out in both ULNT1 and neutral positions of the shoulder and arm. From these two starting positions a KIN-COM(®) dynamometer carried out passive elbow extension while EMG activity of 10 arm and shoulder muscles, elbow-flexor resistive torque and elbow extension ROM were measured concurrently. The result showed that, in the ULNT1 position, increased EMG activity of the involved muscles, increased elbow extension resistive torque and pain responses occurred much earlier in the range of elbow extension in the CTS group compared to healthy controls. These findings demonstrated increased mechanosensitivity of the median nerve in CTS patients compared to healthy controls. PMID:23561861

  2. The cholesterol levels in median nerve and post-mortem interval evaluation.

    PubMed

    Vacchiano, G; Maldonado, A Luna; Ros, M Matas; Di Lorenzo, P; Pieri, M

    2016-08-01

    Cholesterol levels in the median nerve were studied at various post-mortem intervals (PMIs). Single median nerve samples were collected from the wrists of 36 subjects during forensic autopsies of subjects with known circumstances and times of death. Although the absolute values varied, increments in cholesterol concentration were recorded. Subsequently, 16 subjects who did not suffer of any neurological and/or metabolic diseases with known times and circumstances of death were enrolled. For each enrolled subject, two samples were collected from the wrist at an interval of approximately two hours (t1 and t2). The obtained results revealed a gradual increase in cholesterol level with increasing time since death. The cholesterol concentration data obtained for each subject at t1 and t2 were correlated with the time since death, a linear interpolation was applied, and the PMI was back-calculated. Similar trends were obtained for the samples collected at similar PMIs; thus, three groups were considered: PMI<48h, 4878h. Good correlation coefficients were obtained, especially for the first group (R(2)=0.9362) for which the PMI could be calculated with an error that ranged from -4 to 5.9h. Although it requires further confirmation via analyses of larger numbers of samples, the method proposed here can currently be applied to PMI determinations. PMID:26826850

  3. Mechanisms responsible for the effect of median nerve electrical stimulation on traumatic brain injury-induced coma: orexin-A-mediated N-methyl-D-aspartate receptor subunit NR1 upregulation

    PubMed Central

    Feng, Zhen; Du, Qing

    2016-01-01

    Electrical stimulation of the median nerve is a noninvasive technique that facilitates awakening from coma. In rats with traumatic brain injury-induced coma, median nerve stimulation markedly enhances prefrontal cortex expression of orexin-A and its receptor, orexin receptor 1. To further understand the mechanism underlying wakefulness mediated by electrical stimulation of the median nerve, we evaluated its effects on the expression of the N-methyl-D-aspartate receptor subunit NR1 in the prefrontal cortex in rat models of traumatic brain injury-induced coma, using immunohistochemistry and western blot assays. In rats with traumatic brain injury, NR1 expression increased with time after injury. Rats that underwent electrical stimulation of the median nerve (30 Hz, 0.5 ms, 1.0 mA for 15 minutes) showed elevated NR1 expression and greater recovery of consciousness than those without stimulation. These effects were reduced by intracerebroventricular injection of the orexin receptor 1 antagonist SB334867. Our results indicate that electrical stimulation of the median nerve promotes recovery from traumatic brain injury-induced coma by increasing prefrontal cortex NR1 expression via an orexin-A-mediated pathway. PMID:27482224

  4. Mechanisms responsible for the effect of median nerve electrical stimulation on traumatic brain injury-induced coma: orexin-A-mediated N-methyl-D-aspartate receptor subunit NR1 upregulation.

    PubMed

    Feng, Zhen; Du, Qing

    2016-06-01

    Electrical stimulation of the median nerve is a noninvasive technique that facilitates awakening from coma. In rats with traumatic brain injury-induced coma, median nerve stimulation markedly enhances prefrontal cortex expression of orexin-A and its receptor, orexin receptor 1. To further understand the mechanism underlying wakefulness mediated by electrical stimulation of the median nerve, we evaluated its effects on the expression of the N-methyl-D-aspartate receptor subunit NR1 in the prefrontal cortex in rat models of traumatic brain injury-induced coma, using immunohistochemistry and western blot assays. In rats with traumatic brain injury, NR1 expression increased with time after injury. Rats that underwent electrical stimulation of the median nerve (30 Hz, 0.5 ms, 1.0 mA for 15 minutes) showed elevated NR1 expression and greater recovery of consciousness than those without stimulation. These effects were reduced by intracerebroventricular injection of the orexin receptor 1 antagonist SB334867. Our results indicate that electrical stimulation of the median nerve promotes recovery from traumatic brain injury-induced coma by increasing prefrontal cortex NR1 expression via an orexin-A-mediated pathway. PMID:27482224

  5. Charcot-Marie-Tooth 1A concurrent with schwannomas of the spinal cord and median nerve.

    PubMed

    Kwon, Joo Young; Chung, Ki Wha; Park, Eun Kyung; Park, Sun Wha; Choi, Byung-Ok

    2009-08-01

    We identified Charcot-Marie-Tooth disease type 1A (CMT1A) in a family with schwannomas in the spinal cord and median nerve. The CMT1A in this family showed an autosomal dominant pattern, like other CMT patients with PMP22 duplication, and the family also indicated a possible genetic predisposition to schwannomas by 'mother-to-son' transmission. CMT1A is mainly caused by duplication of chromosome 17p11.2-p12 (PMP22 gene duplication). A schwannoma is a benign encapsulated tumor originating from a Schwann cell. A case of hereditary neuropathy with liability to pressure palsies (HNPP) concurrent with schwannoma has been previously reported. Although it seems that the co-occurrence of CMT1A and schwannomas in a family would be the result of independent events, we could not completely ignore the possibility that the coincidence of two diseases might be due to a shared genetic background. PMID:19654968

  6. A widely displaced Galeazzi-equivalent lesion with median nerve compromise

    PubMed Central

    Galanopoulos, Ilias; Fogg, Quentin; Ashwood, Neil; Fu, Katherine

    2012-01-01

    We present the case of a 14-year-old boy with a right distal radial fracture accompanied by a severely displaced complete distal ulnar physeal separation and associated median nerve compromise. This injury is known as Galeazzi-equivalent lesion in children and is an extremely rare injury associated with growth arrest. Recognition of the lesion can be difficult but wide displacement may be associated with other significant injuries such as neurovascular compromise. Prompt intervention reversed the neurological symptoms. At 10-month postoperation there was neither growth arrest nor loss of motion. Complete separation of the ulna physis remains often because of soft tissue interposition or capsule problems and prompt reduction is recommended in the literature as a priority. PMID:22907852

  7. From the brachial plexus to the hand, multiple connections between the median and ulnar nerves may serve as bypass routes for nerve fibres.

    PubMed

    Yang, H; Gil, Y; Kim, S; Bang, J; Choi, H; Lee, H Y

    2016-07-01

    Axons from the median and ulnar nerves can pass to each other through aberrant connections between them. Multiple interconnections between the nerves may provide a detour route for nerve fibres going to the hand. We investigated the incidence of variations and the associations between them in 90 cadaveric upper limbs. In 91% of upper limbs, one to five variations were found, with several statistically significant associations. The contribution of the C8 nerve to the lateral cord was positively associated with an accessory contribution of the lateral cord to the ulnar nerve. The latter variation showed positive association with the occurrence of any of the variations in the hand itself. Ulnar innervation of the superficial head of the flexor pollicis brevis was positively associated with the Riche-Cannieu communication. The co-existence of the variations and their associations may be the explanation for unusual clinical findings related to median and ulnar conduction, which appear contrary to anatomical knowledge. PMID:26763269

  8. Laser welding of rat's facial nerve.

    PubMed

    Hwang, Kun; Kim, Sun Goo; Kim, Dae Joong; Lee, Chang Hyun

    2005-11-01

    The aim of this study is to compare regeneration of the severed nerves that were repaired by laser welding with those repaired by microsurgical suturing and evaluate the value in use of laser nerve welding in the head and neck area. In 12 rats the buccal branches of the facial nerves on the both sides were transected, and CO2 laser welding of the epineurium was performed on the right side and microsurgical suture technique was applied on the left side. In six rats Cholera Toxin B Subunit (CTb) was injected in the epineurium distal to the nerve anastomosis site at postoperative week 4. Another six rats were treated exactly in the same way in postoperative week 8. Six normal rats were used as controls. Intact facial nerve was observed after injection of CTb as well. Neurons of facial nuclei labeled positively by CTb were detected immunohistochemically, and the numbers were counted. CTb-positive neurons in the control group were 1311 +/- 258 (n = 6). CTb-positive neurons in the group (n = 6) with laser nerve welding were 1174 +/- 122 in postoperative week 4 and 1562 +/- 565 in postoperative week 8. CTb-positive neurons in the group (n = 6) with microsurgical suture were 1066 +/- 89 in postoperative week 4 and 1443 +/- 531 in postoperative week 8. CTb-positive neurons were seen significantly more in the group with laser welding than in the group with microsurgical suture in postoperative week (P = 0.028), but there was not much difference in postoperative week 8 (P = 0.463). None of 12 rats showed dehiscence at the nerve anastomosis done by laser welding. This study shows that nerve regeneration is more apparent in the nerve repaired by laser welding than in that repaired by microsurgical suture. PMID:16327562

  9. Apparent transverse compressive material properties of the digital flexor tendons and the median nerve in the carpal tunnel.

    PubMed

    Main, Erin K; Goetz, Jessica E; Rudert, M James; Goreham-Voss, Curtis M; Brown, Thomas D

    2011-03-15

    Carpal tunnel syndrome is a frequently encountered peripheral nerve disorder caused by mechanical insult to the median nerve, which may in part be a result of impingement by the adjacent digital flexor tendons. Realistic finite element (FE) analysis to determine contact stresses between the flexor tendons and median nerve depends upon the use of physiologically accurate material properties. To assess the transverse compressive properties of the digital flexor tendons and median nerve, these tissues from ten cadaveric forearm specimens were compressed transversely while under axial load. The experimental compression data were used in conjunction with an FE-based optimization routine to determine apparent hyperelastic coefficients (μ and α) for a first-order Ogden material property definition. The mean coefficient pairs were μ=35.3 kPa, α=8.5 for the superficial tendons, μ=39.4 kPa, α=9.2 for the deep tendons, μ=24.9 kPa, α=10.9 for the flexor pollicis longus (FPL) tendon, and μ=12.9 kPa, α=6.5 for the median nerve. These mean Ogden coefficients indicate that the FPL tendon was more compliant at low strains than either the deep or superficial flexor tendons, and that there was no significant difference between superficial and deep flexor tendon compressive behavior. The median nerve was significantly more compliant than any of the flexor tendons. The material properties determined in this study can be used to better understand the functional mechanics of the carpal tunnel soft tissues and possible mechanisms of median nerve compressive insult, which may lead to the onset of carpal tunnel syndrome. PMID:21194695

  10. Improving the radial nerve neurodynamic test: An observation of tension of the radial, median and ulnar nerves during upper limb positioning.

    PubMed

    Manvell, Joshua J; Manvell, Nicole; Snodgrass, Suzanne J; Reid, Susan A

    2015-12-01

    The radial nerve neurodynamic test (ULNT2b), used to implicate symptoms arising from the radial nerve, is proposed to selectively increase strain of the nerve without increasing strain of adjacent tissue, though this has not been established. This study aimed to determine the upper limb position that results in: (1) the greatest tension of the radial nerve and (2) the greatest difference in tension between the radial nerve and the other two major nerves of the upper limb: median and ulnar. Tension (N) of the radial, median and ulnar nerves was measured simultaneously using three buckle force transducers during seven upper limb positions in the axilla of ten embalmed whole body human cadavers (n = 20 limbs). Repeated measures analysis of variance (ANOVA) with Bonferroni post-hoc tests determined differences in tension between nerves and between limb positions. A Composite position consisting of ULNT2b (scapular depression, shoulder internal rotation, elbow extension, forearm pronation, wrist flexion) with the addition of shoulder abduction 40° and extension 25°, wrist ulnar deviation and thumb flexion demonstrated significantly greater tension of the radial nerve than any other tested position (mean tension 11.32N; 95% CI 10.25, 12.29, p < 0.01), including ULNT2b (2.20N; 1.84, 2.57; p < 0.01). Additionally, the Composite position demonstrated the greatest difference in tension between the radial and median (mean difference 4.88N; 95% CI 3.16, 6.61; p < 0.01) and radial and ulnar nerves (9.26N, 7.54, 10.99; p < 0.01). This position constitutes a biomechanically plausible test to detect neuropathic pain related to the radial nerve. PMID:25892706

  11. [Variations in the configuration of somatosensory evoked potentials following stimulation of the median nerve].

    PubMed

    Strenge, H

    1989-09-01

    The variants of waveform patterns of cervical and cortical somatosensory evoked potentials to median nerve stimulation at the wrist were analysed in 86 normal subjects aged 15 to 71 years. In cervical SEP recordings the components N13, N14 and the trough-shaped variant of P17 showed the highest short-term stability. Immediate changes of the amplitude proportions of subcomponents within the potential, i.e. a lack of uniformity in waveforms, have to be considered normal. Significant associations were found between the occurrence of components N14 and an arm length of more than 68 cm and between the appearance of a plateau configuration of P17 and an age of at least 40 years. Considering definite criteria the latency of P17 can be used as an additional reliable parameter. In cortical SEP recordings the combination of an initial V-shaped pattern and a following bifid W-configuration appeared as the most frequent waveform profile. All parts of the potential but the positive waves of the primary complex revealed a high intraindividual stability. PMID:2507276

  12. Endoscopic Excision of Supracondylar Humeral Spur for Decompression of the Median Nerve and Brachial Artery

    PubMed Central

    Bain, Gregory; Gupta, Prince; Phadnis, Joideep; Singhi, Prahalad K.

    2016-01-01

    The humeral supracondylar process and Struthers ligament comprise a relatively rare but well-known anatomic variant. They are usually asymptomatic but may produce clinical symptoms related to compression of the median nerve or brachial artery below the ligament. Previously, surgery has been performed with an open ligament release and supracondylar process excision. This article reports on the use of endoscopic findings and the method of ligament release and process excision. Endoscopy is a minimally invasive technique that provides excellent visualization and enables the surgeon to perform dissection with magnification and precision. It allows the surgeon to introduce open surgical techniques into the depths of the wound in a controlled manner. Because of the dead space created, there is a risk of hematoma formation. Many of the concepts used in open surgery are now being used for endoscopic surgery, and vice versa. The barriers and differences among endoscopic, arthroscopic, and open procedures are being broken down. We report another endoscopic technique, which is part of the ongoing evolution of musculoskeletal surgery. PMID:27073779

  13. Short-Latency Median-Nerve Somatosensory-Evoked Potentials and Induced Gamma-Oscillations in Humans

    ERIC Educational Resources Information Center

    Fukuda, Miho; Nishida, Masaaki; Juhasz, Csaba; Muzik, Otto; Sood, Sandeep; Chugani, Harry T.; Asano, Eishi

    2008-01-01

    Recent studies have suggested that cortical gamma-oscillations are tightly linked with various forms of physiological activity. In the present study, the dynamic changes of intracranially recorded median-nerve somatosensory-evoked potentials (SEPs) and somatosensory-induced gamma-oscillations were animated on a three-dimensional MR image, and the…

  14. Combined Cubital and Carpal Tunnel Release Results in Symptom Resolution Outside of the Median or Ulnar Nerve Distributions

    PubMed Central

    Chimenti, Peter C.; McIntyre, Allison W.; Childs, Sean M.; Hammert, Warren C.; Elfar, John C.

    2016-01-01

    Background: Resolution of symptoms including pain, numbness, and tingling outside of the median nerve distribution has been shown to occur following carpal tunnel release. We hypothesized that a similar effect would be found after combined release of the ulnar nerve at the elbow with simultaneous release of the median nerve at the carpal tunnel. Methods: 20 patients with combined cubital and carpal tunnel syndrome were prospectively enrolled. The upper extremity was divided into six zones and the location of pain, numbness, tingling, or strange sensations was recorded pre-operatively. Two-point discrimination, Semmes-Weinstein monofilament testing, and validated questionnaires were collected pre-operatively and at six-week follow-up. Results: Probability of resolution was greater in the median nerve distribution than the ulnar nerve for numbness (71% vs. 43%), tingling (86% vs. 75%). Seventy percent of the cohort reported at least one extra-anatomic symptom pre-operatively, and greater than 80% of these resolved at early follow-up. There was a decrease in pain as measured by validated questionnaires. Conclusion: This study documents resolution of symptoms in both extra-ulnar and extra-median distributions after combined cubital and carpal tunnel release. Pre-operative patient counseling may therefore include the likelihood of symptomatic improvement in a non-expected nerve distribution after this procedure, assuming no other concomitant pathology which may cause persistent symptoms. Future studies could be directed at correlating pre-operative disease severity with probability of symptom resolution using a larger population. PMID:27347239

  15. Prevalence of ulnar-to-median nerve motor fiber anastomosis (Riché-Cannieu communicating branch) in hand: An electrophysiological study

    PubMed Central

    Ahadi, Tannaz; Raissi, Gholam Reza; Yavari, Masood; Majidi, Lobat

    2016-01-01

    Background: Two main muscles studied in the hand for evaluation of median nerve injuries are opponens pollicis (OP) and abductor pollicis brevis (APB). However, Riché-Cannieu communicating branch (RCCB) may limit the use of these muscles in electrodiagnosis. This condition is confusing in the case of median nerve injuries. This study was conducted to evaluate the prevalence of RCCB. Methods: Twenty-three consecutive cases of complete median nerve injury were studied. Evoked responses via stimulation of median and ulnar nerves in the wrist and recording with needle in the thenar area were studied. Results: Of the patients, 82.6% exhibited RCCB. In 14 (60.8%) cases the OP and in 19(82.6%) cases APB was supplied by the ulnar nerve. Conclusion: RCCB was detected to be 60.8% in OP and 82.6% in APB, so OP is preferable to APB in the study of median nerve. PMID:27390694

  16. [Injury to the median nerve after minimally invasive decompression: discrepancy between the surgical report and actual course of surgery].

    PubMed

    Kernt, B; Neu, J

    2011-06-01

    A 72-year-old man suffering from carpal tunnel syndrome had undergone minimally invasive decompression by using a SafeGuard® Mini-Open Carpal Tunnel Release System. After the operation the patient presented with a paraesthesia in the median nerve distribution. Two months later an operative revision was performed in another hospital. A partial transection of the median nerve and an incomplete release was seen. The surgeon of the first operation stated that detailed informed consent including the risk of iatrogenic nerve injury had been obtained. Furthermore he referred to the operative report, which mentioned the accuracy of the procedure without any problems or complications during surgery. The Arbitration Board stated that the operative report could not exculpate the surgeon because the findings of the operative revision disagreed with the first operative report. The expert opinion declared that the lesion was a result of an inaccurate operative procedure as the surgeon was not able to demonstrate an anatomical variation of the median nerve. PMID:21604030

  17. Hereditary neuropathy with liability to pressure palsy combined with schwannomas of the median and medial plantar nerves.

    PubMed

    Heckmann, Josef G; Dütsch, Matthias; Buslei, Ralf

    2007-01-01

    A 42-year-old woman was surgically treated for carpal tunnel syndrome, revealing schwannoma of the median nerve. A year later, she developed a tarsal tunnel syndrome. At time of this diagnosis, hereditary neuropathy with liability to pressure palsies (HNPP) was diagnosed genetically and a schwannoma of the medial plantar nerve was treated surgically. The occurrence of HNPP and schwannomas in the same patient might be purely coincidental, but it is tempting to speculate that they share a common genetic basis. PMID:16969831

  18. Median Nerve Injury Due to High-Pressure Water Jet Injection: A Case Report and Review of Literature.

    PubMed

    Emre, Ufuk; Unal, Aysun

    2009-08-01

    High-pressure injuries that occur accidentally are potentially destructive injuries that often affect the nondominant hands of young men. A variety of products such as paint, gasoline, grease, fuel oil, cement, thinner and solvents have been reported as destructive agents. High-pressure water jet injection injuries to soft tissues have rarely been reported. In this study, we present the first case of median nerve injury due to high-pressure water jet injection by a water spray gun. PMID:26815059

  19. Longitudinal design for sonographic measurement of median nerve swelling with controlled exposure to physical work using an animal model

    PubMed Central

    Roll, Shawn C.; Evans, Kevin D.; Volz, Kevin R.; Sommerich, Carolyn M.

    2013-01-01

    This study examined the feasibility of a longitudinal design to sonographically measure swelling of the median nerve due to controlled exposure to a work task and to evaluate the relationship of changes in morphology to diagnostic standards. Fifteen macaca fascicularis pinched a lever in various wrist positions at a self-regulated pace (8 hours/day, 5 days/week, 18–20 weeks). Nerve conduction velocity (NCV) and cross-sectional area (CSA) were obtained every two weeks from baseline through working and a 6-week recovery. Trending across all subjects showed that NCV slowed and CSA at the carpal tunnel increased in the working arm, while no changes were observed in CSA either at the forearm or for any measure in the non-working arm. There was a small negative correlation between NCV and CSA in the working arm. This study provides validation that swelling can be observed using a longitudinal design. Longitudinal human studies are needed to describe the trajectory of nerve swelling for early identification of median nerve pathology. PMID:24139197

  20. Diagnostic value of median nerve ultrasonography for screening of carpal tunnel syndrome in hypothyroid patients: A cross-sectional study

    PubMed Central

    Mehrpour, Masoud; Mirzaasgari, Zahra; Rohani, Mohammad; Safdarian, Mahdi

    2016-01-01

    Background: Carpal tunnel syndrome (CTS) is a common peripheral entrapment neuropathy in patients with hypothyroid. The diagnosis of CTS is usually clinical and confirmed by electrodiagnostic (EDX) procedures. This study aimed to describe the diagnostic accuracy of high-resolution ultrasonography (US) as an alternative method to nerve conduction study (NCS) for the diagnosis of subclinical CTS in patients with hypothyroidism. Methods: Between April 2013 and November 2014, from the patients with the diagnosis of hypothyroidism referring to the institute of endocrinology and metabolism of Firoozgar Hospital, Tehran, Iran, those who met our inclusion criteria entered this cross-sectional study. The patients divided into two groups of subclinical CTS with the age- and gender-matched control group. US measurements of the median nerve cross-sectional area (CSA) in the CT inlet were compared with the NCS results as the gold standard diagnostic test. Results: A total number of 152 wrists of 76 hypothyroid patients were examined in this study. The mean of median nerve CSA at the tunnel inlet was 9.96 ± 2.20 mm2 for the CTS group and 7.08 ± 1.38 mm2 for the control group (P < 0.05). 31 wrists (20.4%) were diagnosed as CTS using NCS while US diagnosed 19 wrists (12.5%) as CTS. Using receiver-operating-characteristics analysis, the sensitivity and specificity of US at the diagnosis of CTS were 45.0 and 95.8%, respectively, with a median nerve CSA cutoff point of 9.8 mm2. Positive and negative predictive values of US were 87.2 and 85.5%, respectively, with a test accuracy of 85.5%. Conclusion: According to our findings, US has an acceptable diagnostic value to confirm CTS in hypothyroid patients. However, it may not replace NCS due to low sensitivity. PMID:27326360

  1. Changes in Clinical Symptoms, Functions, and the Median Nerve Cross-Sectional Area at the Carpal Tunnel Inlet after Open Carpal Tunnel Release

    PubMed Central

    Koh, Young-Do; Kim, Jong Oh; Choi, Shin Woo

    2016-01-01

    Background The aim of this study was to investigate the relationship between clinical symptoms and cross-sectional area (CSA) of the median nerve at the carpal tunnel inlet before and after open carpal tunnel release (CTR). Methods Thirty-two patients (53 hands) that underwent open CTR for idiopathic carpal tunnel syndrome were prospectively enrolled. Median nerve CSA at the carpal tunnel inlet was measured preoperatively and at 2 and 12 weeks after CTR by high resolution ultrasonography. The Boston carpal tunnel questionnaire (BCTQ) was also completed at these times. Results BCTQ symptom (BCTQ-S) score was significantly improved at 2 weeks postoperatively, but BCTQ function (BCTQ-F) score and CSA were significantly improved at 12 weeks postoperatively. Preoperative CSA was significantly correlated with preoperative BCTQ-S and BCTQ-F scores but was not significantly correlated with postoperative BCTQ scores or postoperative changes in BCTQ scores. Postoperative median nerve CSA was not significantly correlated with postoperative BCTQ-S or BCTQ-F scores, and postoperative changes in median nerve CSA were not significantly correlated with postoperative changes in BCTQ-S or BCTQ-F scores. Conclusions The study shows clinical symptoms resolve rapidly after open CTR, but median nerve swelling and clinical function take several months to recover. In addition, preoperative median nerve swelling might predict preoperative severities of clinical symptoms and functional disabilities. However, postoperative reductions in median nerve swelling were not found to reflect postoperative reductions in clinical symptoms or functional disabilities. PMID:27583113

  2. Precision pinch performance in patients with sensory deficits of the median nerve at the carpal tunnel.

    PubMed

    Yen, Wei-Jang; Kuo, Yao-Lung; Kuo, Li-Chieh; Chen, Shu-Min; Kuan, Ta-Shen; Hsu, Hsiu-Yun

    2014-01-01

    To investigate how sensory symptoms impact the motor control of hands, in this study we examined the differences in conventional sensibility assessments and pinch force control in the pinch-holding-up activity (PHUA) test between carpal tunnel syndrome (CTS) patients and healthy controls. CTS patients (n = 82) with 122 affected hands and an equal number of control subjects were recruited to participate in the threshold, discrimination, and PHUA tests. The patients showed significantly poorer hand sensibility and lower efficiency of force adjustment in the PHUA test as compared with the control subjects. Baseline pinch strength and the percentage of maximal pinch strength for the PHUA were significantly higher for the subgroup of sensory nerve action potential (SNAP) of <16 μV than for the subgroup of SNAP of 16 μV. Using a PHUA perspective to analyze the efficiency of force-adjustment could assist the clinical detection of sensory nerve dysfunction. PMID:24496877

  3. Carpal tunnel syndrome due to a plexiform neurofibroma of the median nerve in a neurofibromatosis type 1 patient: clinical approach.

    PubMed

    Freitas, Daniel; Aido, Ricardo; Sousa, Marco; Costa, Luís; Oliveira, Vânia; Cardoso, Pedro

    2013-01-01

    The authors report the case of a 56-year-old male patient with neurofibromatosis type 1 (NF1) diagnosed during adolescence and with an insidious clinical evolution, characterised by an exuberant cutaneous involvement, referred to the orthopaedics outpatient clinic presenting with carpal tunnel syndrome secondary to a plexiform neurofibroma of the median nerve. A comprehensive clinical approach is discussed, considering the natural history of the disease and its potential complications, as well as the lack of consensus regarding standard therapeutic options for the compressive peripheral neuropathies in the NF1 disease. PMID:23853185

  4. Motor nerve conduction velocity (MCV) and lead content in sciatic nerve of lead-exposed rats

    SciTech Connect

    Maehara, N.; Uchino, E.; Terayama, K.; Ohno, H.; Yamamura, K.

    1986-07-01

    There have been many pathological and electrophysiological studies of peripheral nerves in inorganic lead intoxication. Peripheral nerve conduction velocity (NCV) has been used as an objective measure of the effects of lead on the peripheral nerve function and has been examined with blood lead content. There have been few reports on the changes in NCV related to lead content in the peripheral nerve tissue under lead poisoning. In the present study, the authors have examined motor nerve conduction velocity (MCV) of the tail by a non-invasive method and lead content of the peripheral nerve in lead-exposed rats. Furthermore, they have attempted to assess the relationship between these two parameters.

  5. Median Sacral Artery, Sympathetic Nerves, and the Coccygeal Body: A Study Using Serial Sections of Human Embryos and Fetuses.

    PubMed

    Jin, Zhe Wu; Cho, Kwang Ho; Jang, Hyung Suk; Murakami, Gen; Rodríguez-Vázquez, Jose Francisco

    2016-07-01

    To examine how the median sacral artery (MSA) is involved with the coccygeal body or glomus coccygeum, we studied serial frontal or sagittal sections of 14 embryos (approximately 5-6 weeks of gestation) and 12 fetuses (10-18 weeks). At five weeks, the caudal end of the dorsal aorta (i.e., MSA) accompanied putative sympathetic ganglion cells in front of the upper coccygeal and lower sacral vertebrae. At six weeks, a candidate for the initial coccygeal body was identified as a longitudinal arterial plexus involving nerve fibers and sympathetic ganglion cells between arteries. At 10-18 weeks, the MSA exhibited a highly tortuous course at the lower sacral and coccygeal levels, and was attached to and surrounded by veins, nerve fibers, and sympathetic ganglion cells near and between the bilateral origins of the levator ani muscle. Immunohistochemistry demonstrated expression of tyrosine hydroxylase and chromogranin A in the nerves. However, throughout the stages examined, we found no evidence suggestive of an arteriovenous anastomosis, such as well-developed smooth muscle. An acute anterior flexure of the vertebrae at the lower sacrum, as well as regression of the secondary neural tube, seemed to induce arterial plexus formation from an initial straight MSA. Nerves and ganglion cells were likely to be secondarily involved with the plexus because of the close topographical relationship. However, these nerves might play a major role in the extreme change into adult morphology. An arteriovenous anastomosis along the MSA might be an overinterpretation, at least in the prenatal human. Anat Rec, 299:819-827, 2016. © 2016 Wiley Periodicals, Inc. PMID:27149546

  6. Median Nerve Compression in Carpal Tunnel Caused by a Giant Lipoma

    PubMed Central

    Fazilleau, F.; Williams, T.; Richou, J.; Sauleau, V.; Le Nen, D.

    2014-01-01

    A lipoma is a common, benign soft-tissue tumor that rarely arises in the upper limb. When one does occur in the hand, the location of the lipoma can cause nerve compression, which can mimic carpal tunnel symptoms. Magnetic resonance imaging is the visualization modality of choice for diagnosis and surgical planning of lipomas. Surgical resection is recommended to relieve the neurological manifestations of this disease. The surgeon should always suspect liposarcoma first before voluminous, atypical, or recurrent tumors are considered. PMID:24876983

  7. A single dose of lorazepam reduces paired-pulse suppression of median nerve evoked somatosensory evoked potentials.

    PubMed

    Stude, Philipp; Lenz, Melanie; Höffken, Oliver; Tegenthoff, Martin; Dinse, Hubert

    2016-05-01

    Paired-pulse behaviour in the somatosensory cortex is an approach to obtain insights into cortical processing modes and to obtain markers of changes of cortical excitability attributable to learning or pathological states. Numerous studies have demonstrated suppression of the response to the stimulus that follows a first one after a short interval, but the underlying mechanisms remain elusive, although there is agreement that GABAergic mechanisms seem to play a crucial role. We therefore aimed to explore the influence of the GABAA agonist lorazepam on paired-pulse somatosensory evoked potentials (SEPs). We recorded and analysed SEPs after paired median nerve stimulation in healthy individuals before and after they had received a single dose of 2.5 mg of lorazepam as compared with a control group receiving placebo. Paired-pulse suppression was expressed as a ratio of the amplitudes of the second and the first peaks. We found that, after lorazepam application, paired-pulse suppression of the cortical N20 component remained unchanged, but suppression of the N20-P25 complex was significantly reduced, indicative of GABAergic involvement in intracortical processing. Our data suggest that lorazepam most likely enhances inhibition within the cortical network of interneurons responsible for creating paired-pulse suppression, leading to reduced inhibitory drive with a subsequently reduced amount of suppression. The results provide further evidence that GABAA -mediated mechanisms are involved in the generation of median nerve evoked paired-pulse suppression. PMID:26929110

  8. Schwannoma of the Median Nerve at the Wrist and Palmar Regions of the Hand: A Rare Case Report

    PubMed Central

    Kütahya, Harun; Güleç, Ali; Güzel, Yunus; Kacira, Burkay; Toker, Serdar

    2013-01-01

    Schwannomas are also known as neurolemmas that are usually originated from Schwann cells located in the peripheric nerve sheaths. They are the most common tumours of the hand (0.8–2%). They usually present solitary swelling along the course of the nerve however multiple lesions may be present in cases of NF type 1, familial neurofibromatosis, and sporadic schwannomatosis. Schwannomas are generally represented as an asymptomatic mass; however pain, numbness and fatigue may take place with the increasing size of the tumour. EMG (electromyelography), MRI (magnetic resonance imagination), and USG (ultrasound) are helpful in the diagnosis. Surgical removal is usually curative. In this paper, we present a 24-year-old male referred to our clinic for a lump located at the volar side of the left wrist and a lump located in his left palm and numbness at his 3rd and 4th fingers. Total excision was performed for both lesions. Histopathological examination of the masses revealed typical features of schwannoma. At the 6th-month followup the patient was symptom-free except for slight paresthesia of the 3rd and the 4th fingers. For our knowledge, this is the second case in the literature presenting wrist and palm involvement of the median nerve schwannoma. PMID:24062961

  9. Somatosensory evoked potentials in cervical spondylosis. Correlation of median, ulnar and posterior tibial nerve responses with clinical and radiological findings.

    PubMed

    Yu, Y L; Jones, S J

    1985-06-01

    Somatosensory evoked potentials (SEPs) following median, ulnar and tibial nerve stimulation were recorded from sites over the shoulders, neck and scalp in 34 patients with cervical spondylosis. Twenty control subjects were matched for sex and age. Detailed clinical and radiological data were assembled, with particular attention to the sensory modalities impaired and the locus and severity of cord compression. The patients were divided clinically into 4 groups: combined myelopathy and radiculopathy (6 cases), myelopathy alone (15), radiculopathy (6) and neck pain (7). Four cases are described in detail. SEP abnormalities were strongly correlated with clinical myelopathy, but not with radiculopathy. Median and ulnar nerve responses were less often affected than tibial, even with myelopathy above C6 level. Tibial nerve SEP abnormalities were strongly correlated with posterior column signs on the same side of the body, but not with anterolateral column sensory signs. In myelopathy cases, the SEP examination appeared to be more sensitive to sensory pathway involvement than clinical sensory testing. SEP abnormalities were infrequent in cases of radiculopathy and neck pain, bearing no relation to the clinical locus of root lesions. Abnormal SEPs consistent with subclinical posterior column involvement, however, were recorded in 1 patient with radiculopathy and 2 with neck pain. Follow-up recordings made postoperatively in 7 myelopathy cases reflected the clinical course (improvement, deterioration or no change) in 4, but failed to reflect improvement in 3. The correlation of SEP findings with radiological data was generally poor. SEP abnormalities were detected in 6 out of 8 patients with clinical myelopathy but no radiological evidence of posterior cord compression, suggesting that impairment of the blood supply may be an important factor contributing to cord damage. An application for SEPs in the clinical management of cervical spondylosis may lie in the detection of

  10. Effect of oblique nerve grafting on peripheral nerve regeneration in rats.

    PubMed

    Kotulska, Katarzyna; Marcol, Wiesław; Larysz-Brysz, Magdalena; Tendera, Zofia; Malinowska-Kołodziej, Izabela; Slusarczyk, Wojciech; Jedrzejowska-Szypułka, Halina; Lewin-Kowalik, Joanna

    2006-01-01

    Current methods of peripheral nerve repair are to rejoin cut nerve stumps directly or to bridge large gaps with autologous nerve grafts. In both cases the surface of nerve stump endings is typically cut perpendicularly to the long axis of the nerve. The outcome of such operations, however, is still not satisfactory. In this study, we examine the effect of oblique nerve cutting and grafting on morphological as well as functional features of regeneration. In adult rats, sciatic nerve was cut and rejoined either directly or using an autologous graft, at 90 degrees or 30 degrees angle. Functional regeneration was assessed by walking track analysis during 12-week follow-up. Afterwards muscle weight was measured and histological studies were performed. The latter included nerve fibers and Schwann cells counting, as well as visualization of scar formation and epineural fibrosis. Nerves cut obliquely and rejoined showed better functional recovery than perpendicularly transected. Similar effect was observed after oblique grafting when compared to perpendicular one. Numbers of nerve fibers growing into the distal stump of the nerve as well as the number of Schwann cells were significantly higher in obliquely than in perpendicularly operated nerves. Moreover, growing axons were arranged more regularly following oblique treatment. These data indicate that joining or grafting the nerve stumps at acute angle is a more profitable method of nerve repair than the standard procedure performed at right angle. PMID:17066410

  11. A comparative study of acellular nerve xenografts and allografts in repairing rat facial nerve defects.

    PubMed

    Huang, Haitao; Xiao, Hongxi; Liu, Huawei; Niu, Yu; Yan, Rongzeng; Hu, Min

    2015-10-01

    Acellular nerves are composed of a basal lamina tube, which retains sufficient bioactivity to promote axon regeneration, thereby repairing peripheral nerve gaps. However, the clinical application of acellular allografts has been restricted due to its limited availability. To investigate whether xenografts, a substitute to allograft acellular nerves in abundant supply, could efficiently promote nerve regeneration, rabbit and rat acellular nerve grafts were used to reconstruct 1 cm defects in Wistar rat facial nerves. Autologous peroneal nerve grafts served as a positive control group. A total of 12 weeks following the surgical procedure, the axon number, myelinated axon number, myelin sheath thickness, and nerve conduction velocity of the rabbit and rat‑derived acellular nerve grafts were similar, whereas the fiber diameter of the rabbit‑derived acellular xenografts decreased, as compared with those of rat‑derived acellular allografts. Autografts exerted superior effects on nerve regeneration; however, no significant difference was observed between the axon number in the autograft group, as compared with the two acellular groups. These results suggested that autografts perform better than acellular nerve grafts, and chemically extracted acellular allografts and xenografts have similar effects on the regeneration of short facial nerve defects. PMID:26239906

  12. [The impairment of A-delta fibers in median nerve compression at the wrist, using the cutaneous silent period].

    PubMed

    Duarte, Juan M; D'Onofrio, Héctor M; Rolón, Juan Ignacio; Bertotti, Alicia C

    2016-01-01

    Carpal tunnel síndrome (CTS) is an entrapment neuropathy of the median nerve at the wrist, that leads to pain, paresthesia and painful dysesthesia. The electrophysiological diagnosis is based upon nerve conduction studies which evaluate thick nerve fibers. Our hypothesis is that there is an additional dysfunction of small fibers in CTS, which correlates with the degree of severity of the neuropathy. A retrospective study of 69 hands that belonged to 47 patients of both sexes (mean age 53.8, years, range 22-87) was performed, and, as a control group, 21 hands which corresponded to the asymptomatic side of those patients were evaluated. Motor and sensory conduction studies, as well as F-waves were performed to classify the neuropathy according to the degree of severity. Cutaneous silent period (CSP) was elicited in all hands. Mean onset latencies and durations of CSP were evaluated. Mean onset latencies were significantly prolonged in neuropathic hands (84.3 ± 16.3 msec) compared to asymptomatic hands (74.8 ± 11.6 msec) (p < 0.05). Mean latencies of the CSP were even prolonged (p < 0.05) in hands affected by a more severe neuropathy. In the 3 hands with most severe neuropathy, a CSP could not be elicited. In CTS an impairment of A-delta fibers was recorded through the CSP. The more severe the neuropathy is, the more impairment of A-delta fibers can be found. CSP may be assessed as a complement of motor and sensory nerve conduction studies in this neuropathy. PMID:27576280

  13. Optical stimulation of the cavernous nerves in the rat prostate

    NASA Astrophysics Data System (ADS)

    Fried, Nathaniel M.; Lagoda, Gwen A.; Scott, Nicholas J.; Su, Li-Ming; Burnett, Arthur L.

    2008-02-01

    Laser nerve stimulation has recently been studied as an alternative to electrical stimulation in neuroscience. Advantages include non-contact stimulation, improved spatial selectivity, and elimination of electrical stimulation artifacts. This study explores laser stimulation of the rat cavernous nerves, as a potential alternative to electrical nerve mapping during nerve-sparing radical prostatectomy. The cavernous nerves were surgically exposed in a total of 10 male rats. A Thulium fiber laser stimulated the nerves, with a wavelength of 1870 nm, pulse energy of 7.5 mJ, radiant exposure of 1 J/cm2, pulse duration of 2.5 ms, pulse rate of 10 Hz, and 1-mm laser spot diameter, for a stimulation time of 60 s. A significant increase in the intracavernosal pressure was detected upon laser stimulation, with pressure returning to baseline levels after stimulation. This study demonstrates the feasibility of non-contact laser stimulation of the cavernous nerves using near-infrared laser radiation.

  14. Fibrolipomatous hamartoma of the median nerve: A cause of acute bilateral carpal tunnel syndrome in a three-year-old child: A case report and comprehensive literature review

    PubMed Central

    Senger, Jenna-Lynn; Classen, Dale; Bruce, Garth; Kanthan, Rani

    2014-01-01

    A three-year-old boy was investigated for inexplicable incessant crying. On examination, his left wrist was mildly swollen (three to four months) and sensitive. Exploration and carpal tunnel decompression of the left wrist with incisional biopsy was performed for the presence of a fusiform swelling intimately associated with the median nerve. Histopathology revealed the presence of enlarged nerve bundles admixed with mature fat cells and diffuse fibroblastic proliferation. Three months later, he underwent urgent contralateral carpal tunnel decompression for a similar presentation. The final diagnosis was bilateral fibrolipomatous hamartoma (FLH) of the median nerves causing acute bilateral compression neuropathy. FLH of the median nerve is an extremely unusual cause of acute bilateral carpal tunnel syndrome in a young child presenting with ‘incessant crying’. A comprehensive review of FLH including epidemiology, etiology, clinical presentation, differential diagnosis, imaging, pathology, treatment and prognosis is discussed. PMID:25332651

  15. Facial nerve identification with fluorescent dye in rats.

    PubMed

    de Melo, Giulianno Molina; Cervantes, Onivaldo; Covolan, Luciene; Baptista, Heloisa Allegro; Ferreira, Elenn Soares; Abrahao, Marcio

    2016-02-01

    PURPOSE The parotidectomy technique still has an elevated paresis and paralysis index, lowering patient life's quality. The correct identification of the facial nerve can prevent nerve damage. Fluorescent dye identifies nerves in experimental studies but only few articles focused its use on facial nerve study in parotidectomies. We aimed to stain the rat facial nerve with fluorescent dye to facilitate visualization and dissection in order to prevent injuries. METHODS Forty adult male Wistar rats were submitted to facial injection of saline solution (Gsf-control group, 10) or fluorescent dye solution (Gdye group, 30) followed by parotidectomy preserving the facial nerve, measuring the time for localization and facility of localization (LocTime and LFN). Nerve function was assessed using the Vibrissae Movements (PMV) and Eyelid Closure Motion (PFP) scores. RESULTS Nerve localization was faster in Gdye group, with 83% Easy LFN rate. The Gdye group presented with low nerve injury degree and better PMV and PFP scores, with high sensitivity and accuracy. CONCLUSIONS This experimental method of facial nerve fluorescence was effective for intraoperative nerve visualization, identification and preservation. The technique may be used in future facial nerve studies, translated to humans, contributing to the optimization of parotid surgery in the near future. PMID:26959618

  16. Distribution of sodium channels during nerve elongation in rat peripheral nerve.

    PubMed

    Ichimura, Harumitsu; Shiga, Takashi; Abe, Ichiro; Hara, Yuki; Terui, Naoto; Tsujino, Akihito; Ochiai, Naoyuki

    2005-01-01

    A number of studies have investigated electrophysiological and morphological changes of peripheral nerves during gradual elongation. There has been, however, no report on the distribution of sodium channels at Ranvier's nodes during peripheral nerve elongation. We investigated peripheral nerve injury after the gradual elongation of rat sciatic nerves. Indirect nerve elongation was induced by leg lengthening at a rate of 3 mm/day by 15 or 30 mm. At 7 days after the leg lengthening, the electrophysiological properties of sciatic nerves, the ultrastructures of the Ranvier's nodes and axons, and the distribution of voltage-dependent sodium channels were examined. In the control nerves, most sodium channels were localized at Ranvier's nodes in myelinated axons, providing the physiological basis of saltatory conduction. In the elongated nerves, both the amplitude and conduction velocity of compound nerve action potential decreased following leg lengthening. The elongated nerves also showed paranodal demyelination in Ranvier's nodes longer than those in the control group. In addition, the distribution of sodium channels became diffuse or disappeared at Ranvier's nodes of elongated nerves. The diffuse distribution and/or disappearance of sodium channels may underlie the electrophysiological changes in compound nerve action potential induced by nerve elongation. PMID:15815871

  17. The role of median nerve terminal latency index in the diagnosis of carpal tunnel syndrome in comparison with other electrodiagnostic parameters

    PubMed Central

    Vahdatpour, Babak; Khosrawi, Saeid; Chatraei, Maryam

    2016-01-01

    Background: Carpal tunnel syndrome (CTS) considers the most common compression neuropathy, which nerve conduction studies (NCSs) used for its detection routinely and universally. This study was performed to determine the value of the median TLI and other NCS variables and to investigate their sensitivity and specificity in the diagnosis of CTS. Materials and Methods: The study was carried out among 100 hands of healthy volunteers and 50 hands of patients who had a positive history of paresthesia and numbness in upper extremities. Information including age, gender, and result of sensory and motor nerve conduction velocity (MNCV), peak latency difference of median and ulnar nerves of fourth digit (M4-U4 peak latency difference), and TLI were recorded for analysis. Sensitivity and specificity of electro diagnostic parameters in the diagnosis of CTS was investigated. Results: Normal range of the median nerve TLI was 0.43 ± 0.077. There was no significant difference between two groups for MNCV means (P = 0. 45). Distal sensory latency and distal motor latency (DML) of median nerve and fourth digit median-ulnar peak latency differences (PM4-PU4) for CTS group was significantly higher (P < 0.001) and mean for sensory nerve conduction velocity was significantly higher in control group (P < 0.001). The most sensitive electrophysiological finding in CTS patients was median TLI (82%), but the most specific one was DML (98%). Conclusion: Although in early stages of CTS, we usually expect only abnormalities in the sensory studies, but TLI may better demonstrate the effect on median nerve motor fiber even in mild cases of CTS. PMID:27376049

  18. Effects of Alcohol Injection in Rat Sciatic Nerve

    PubMed Central

    Mazoch, Mathew J.; Cheema, Gulraiz A.; Suva, Larry J.; Thomas, Ruth L.

    2015-01-01

    Background Previous studies have shown that the injection of dehydrated alcohol has been successful for the treatment of Morton's neuroma in the foot. In this study, we determined the cellular effect of injection of alcohol into and around the sciatic nerve of rats, and measured the extent of cell necrosis and/or any associated histologic or inflammatory changes. Methods Twenty-two male (~375g) Wistar rats were randomized into two groups each receiving alcohol injections into or around the sciatic nerve after nerve exposure under sterile technique. Group 1 rats were injected with a 0.5ml solution of 0.5% Marcaine in the left sciatic nerve as a control group. In the right sciatic nerve a 0.5ml solution of 4% ethanol with 0.5% Marcaine was injected. Group 2 rats received 0.5ml of 20%ethanol with 0.5% Marcaine injected into the left sciatic nerve and 0.5 ml of 30% ethanol with 0.5% Marcaine injected into the right sciatic nerve. In each group, the rats were placed in 3 subgroups: intraneural, perineural, perimuscular injections. All rats were sacrificed and tissue harvested for histologic evaluation at day 10 post injection. Results No evidence of alcohol-associated cell necrosis, apoptosis or apparent inflammation was observed in histologic specimens of any injected nerves, perineural tissue, or muscles in controls or experimental groups regardless of concentration of ethanol injected on day 10. Conclusion We concluded that alcohol injection (≤30% ethanol) into and/or around the sciatic nerve or the adjacent muscle of rats has no histologic evidence of necrosis or inflammation to the nerve or surrounding tissue. There was no observable histological change in apoptosis, or cell number, in response to the alcohol injection. PMID:25097192

  19. Assessment of the Kinetic Trajectory of the Median Nerve in the Wrist by High-Frequency Ultrasound

    PubMed Central

    Lin, Yi-Hsun; Hsieh, Mei-Yu; Su, Fong-Chin; Wang, Shyh-Hau

    2014-01-01

    Carpal tunnel syndrome (CTS) is typically diagnosed by physical examination or nerve conduction measurements. With these diagnostics however it is difficult to obtain anatomical information in the carpal tunnel. To further improve the diagnosis of CTS, an attempt using 30 MHz high-frequency ultrasound to noninvasively detect the local anatomical structures and the kinetic trajectory of the median nerve (MN) in the wrist was explored. Measurements were performed on the right wrist of 14 asymptomatic volunteers. The kinetic trajectory of the MN corresponding to flexion (from 0° to 90°) and extension (from 90° to 0°) movements of the fingers were detected by a cross correlation-based motion tracking technique. The average displacements of the MN according to finger movements were measured to be 3.74 and 2.04 mm for male and female subjects, respectively. Moreover, the kinetic trajectory of the MN in both the ulnar-palmar and total directions generally follows a sigmoidal curve tendency. This study has verified that the use of high-frequency ultrasound imaging and a motion tracking technique to sensitively detect the displacement and kinetic trajectory of the MN for the assessment of CTS patients is feasible. PMID:24787637

  20. Assessment of the kinetic trajectory of the median nerve in the wrist by high-frequency ultrasound.

    PubMed

    Lin, Yi-Hsun; Hsieh, Mei-Yu; Su, Fong-Chin; Wang, Shyh-Hau

    2014-01-01

    Carpal tunnel syndrome (CTS) is typically diagnosed by physical examination or nerve conduction measurements. With these diagnostics however it is difficult to obtain anatomical information in the carpal tunnel. To further improve the diagnosis of CTS, an attempt using 30 MHz high-frequency ultrasound to noninvasively detect the local anatomical structures and the kinetic trajectory of the median nerve (MN) in the wrist was explored. Measurements were performed on the right wrist of 14 asymptomatic volunteers. The kinetic trajectory of the MN corresponding to flexion (from 0° to 90°) and extension (from 90° to 0°) movements of the fingers were detected by a cross correlation-based motion tracking technique. The average displacements of the MN according to finger movements were measured to be 3.74 and 2.04 mm for male and female subjects, respectively. Moreover, the kinetic trajectory of the MN in both the ulnar-palmar and total directions generally follows a sigmoidal curve tendency. This study has verified that the use of high-frequency ultrasound imaging and a motion tracking technique to sensitively detect the displacement and kinetic trajectory of the MN for the assessment of CTS patients is feasible. PMID:24787637

  1. Cobalt iontophoresis of sensory nerves in the rat lung.

    PubMed

    El-Bermani, A W; Chang, T L

    1979-02-01

    By iontophoretically introducing, first, cobalt and, subsequently, sulfide ions into the vagus nerve, it is possible to trace sensory nerves to their endings in the rat lung. Nerve fibers and terminals are found predominantly in the adventitia of the airways and blood vessels. Some nerves are found in the submucosa of the bronchi and bronchioles. Some are found in the cardiac muscle on the periphery of pulmonary veins, and a few nerves are seen to end among smooth muslces of the blood vessels and the airways. At least three types of nerve endings can be identified at the light microscopic level: (1) free nerve endings; (2) brush-like endings; (3) knob-like terminals. PMID:760496

  2. Ultrasound assessment of the median nerve: a biomarker that can help in setting a treat to target approach tailored for carpal tunnel syndrome patients.

    PubMed

    El Miedany, Yasser; El Gaafary, Maha; Youssef, Sally; Ahmed, Ihab; Nasr, Annie

    2015-01-01

    Ultrasonography (US) is a valuable tool for confirming the diagnosis of carpal tunnel syndrome (CTS) as it enables the detection of changes in the median nerve shape and rule out anatomic variants as well as space-occupying lesions such as ganglion cysts or tenosynovitis. This work was carried out aiming at: 1. Ultrasonography assessment of the median nerve and its neurovascular blood-flow in CTS patients before and after management. 2. Verify the possibility of using baseline US parameters as a biomarker to predict likely outcomes and frame a treatment plan for CTS patients. 233 CTS subjects diagnosed based on clinical and electrophysiological (NCS) testing were included in this work. US measures at the tunnel inlet included: cross sectional area, flattening ratio and neural Power Doppler (PD) signals. Patients who had severe NCS outcomes or neurological deficit were referred for open surgical decompression; the remaining patients were given the choice of either conservative or surgical management. The main outcome variable was improvement >70% in CTS symptoms. Assessments were carried out at baseline, 1-week, 1-month and 6-months post treatment. Results revealed an inverse relation between the neural vasculature and CTS severity defined by NCS (r = - 0.648). In CTS cases treated conservatively, the US measures started to improve within 1-week, whereas in the surgically treated cohort there was an initial phase of post-operative nerve measures increase, before settling at 1-month time of follow-up. The risk of poor outcomes was significantly higher (RR 3.3) in patients with high median nerve flattening ratio. This risk was most marked in the cohort with nerve flattening associated with longer duration of illness (RR 4.3) and low PD signal (RR 4.1). The results revealed that in addition to the diagnostic value of US in CTS, the detection of increased median nerve neuro-vasculature has a good prognostic value as an indicator of early median nerve affection. PMID

  3. Mesenchymal Stem Cells Enhance Nerve Regeneration in a Rat Sciatic Nerve Repair and Hindlimb Transplant Model

    PubMed Central

    Cooney, Damon S.; Wimmers, Eric G.; Ibrahim, Zuhaib; Grahammer, Johanna; Christensen, Joani M.; Brat, Gabriel A.; Wu, Lehao W.; Sarhane, Karim A.; Lopez, Joseph; Wallner, Christoph; Furtmüller, Georg J.; Yuan, Nance; Pang, John; Sarkar, Kakali; Lee, W. P. Andrew; Brandacher, Gerald

    2016-01-01

    This study investigates the efficacy of local and intravenous mesenchymal stem cell (MSC) administration to augment neuroregeneration in both a sciatic nerve cut-and-repair and rat hindlimb transplant model. Bone marrow-derived MSCs were harvested and purified from Brown-Norway (BN) rats. Sciatic nerve transections and repairs were performed in three groups of Lewis (LEW) rats: negative controls (n = 4), local MSCs (epineural) injection (n = 4), and systemic MSCs (intravenous) injection (n = 4). Syngeneic (LEW-LEW) (n = 4) and allogeneic (BN-LEW) (n = 4) hindlimb transplants were performed and assessed for neuroregeneration after local or systemic MSC treatment. Rats undergoing sciatic nerve cut-and-repair and treated with either local or systemic injection of MSCs had significant improvement in the speed of recovery of compound muscle action potential amplitudes and axon counts when compared with negative controls. Similarly, rats undergoing allogeneic hindlimb transplants treated with local injection of MSCs exhibited significantly increased axon counts. Similarly, systemic MSC treatment resulted in improved nerve regeneration following allogeneic hindlimb transplants. Systemic administration had a more pronounced effect on electromotor recovery while local injection was more effective at increasing fiber counts, suggesting different targets of action. Local and systemic MSC injections significantly improve the pace and degree of nerve regeneration after nerve injury and hindlimb transplantation. PMID:27510321

  4. Mesenchymal Stem Cells Enhance Nerve Regeneration in a Rat Sciatic Nerve Repair and Hindlimb Transplant Model.

    PubMed

    Cooney, Damon S; Wimmers, Eric G; Ibrahim, Zuhaib; Grahammer, Johanna; Christensen, Joani M; Brat, Gabriel A; Wu, Lehao W; Sarhane, Karim A; Lopez, Joseph; Wallner, Christoph; Furtmüller, Georg J; Yuan, Nance; Pang, John; Sarkar, Kakali; Lee, W P Andrew; Brandacher, Gerald

    2016-01-01

    This study investigates the efficacy of local and intravenous mesenchymal stem cell (MSC) administration to augment neuroregeneration in both a sciatic nerve cut-and-repair and rat hindlimb transplant model. Bone marrow-derived MSCs were harvested and purified from Brown-Norway (BN) rats. Sciatic nerve transections and repairs were performed in three groups of Lewis (LEW) rats: negative controls (n = 4), local MSCs (epineural) injection (n = 4), and systemic MSCs (intravenous) injection (n = 4). Syngeneic (LEW-LEW) (n = 4) and allogeneic (BN-LEW) (n = 4) hindlimb transplants were performed and assessed for neuroregeneration after local or systemic MSC treatment. Rats undergoing sciatic nerve cut-and-repair and treated with either local or systemic injection of MSCs had significant improvement in the speed of recovery of compound muscle action potential amplitudes and axon counts when compared with negative controls. Similarly, rats undergoing allogeneic hindlimb transplants treated with local injection of MSCs exhibited significantly increased axon counts. Similarly, systemic MSC treatment resulted in improved nerve regeneration following allogeneic hindlimb transplants. Systemic administration had a more pronounced effect on electromotor recovery while local injection was more effective at increasing fiber counts, suggesting different targets of action. Local and systemic MSC injections significantly improve the pace and degree of nerve regeneration after nerve injury and hindlimb transplantation. PMID:27510321

  5. Perineural Dexmedetomidine as an Adjuvant Reduces the Median Effective Concentration of Lidocaine for Obturator Nerve Blocking: A Double-Blinded Randomized Controlled Trial

    PubMed Central

    Lu, Yuechun; Sun, Jian; Zhuang, Xinqi; Lv, Guoyi; Li, Yize; Wang, Haiyun; Wang, Guolin

    2016-01-01

    Research suggests that the addition of dexmedetomidine to local anesthetics can prolong peripheral nerve blocks; however, it is not known whether dexmedetomidine can reduce the quantity of local anesthetic needed. We hypothesized that adding dexmedetomidine as an adjuvant to an obturator nerve block could reduce the median effective concentration of lidocaine. In this double-blinded randomized trial, 60 patients scheduled for elective transurethral resection of bladder tumors on the lateral wall were randomly divided into two groups: the control group (C group, n = 30) and the dexmedetomidine group (D group, n = 30). Two main branches of the obturator nerve (i.e., anterior and posterior) were identified using neural stimulation at the inguinal level, with only lidocaine used for the C group and 1 μg/kg dexmedetomidine combined with lidocaine used for the D group. The median effective concentration was determined by an up-and-down sequential trial. The ratio of two consecutive concentrations was 1.2. The median effective concentration (95% confidence interval) of lidocaine was 0.57% (0.54%-0.62%) in the C group and 0.29% (0.28%-0.38%) in the D group. The median effective concentration of lidocaine was significantly lower in the D group than in the C group (p < 0.05). These results indicate that dexmedetomidine (1 μg/kg) in combination with lidocaine for obturator nerve block decreases the median effective concentration of lidocaine. Trial Registration: ClinicalTrials.gov NCT02066727 PMID:27341450

  6. Effectively Axonal-supercharged Interpositional Jump-Graft with an Artificial Nerve Conduit for Rat Facial Nerve Paralysis

    PubMed Central

    Niimi, Yosuke; Takeuchi, Yuichi; Sasaki, Ryo; Watanabe, Yorikatsu; Yamato, Masayuki; Miyata, Mariko; Sakurai, Hiroyuki

    2015-01-01

    Background: Interpositional jump graft (IPJG) is a nerve graft axonally supercharged from the hypoglossal nerve. However, for using the technique, an autologous nerve, which should contain the great auricular and sural nerves, must be obtained. Depending on the donor site, unavoidable issues such as nerve disorders and postoperative scarring may appear. To reduce the issues, in this study, the authors developed an end-to-side neurorrhaphy technique with the recipient nerve and an artificial nerve conduit and investigated the efficacy of an IPJG with an artificial nerve conduit in a rat facial nerve paresis model. Methods: A ligature clip was used to crush the facial nerve trunk, thereby creating a partial facial nerve paresis model. An artificial nerve conduit was then prepared with a 10-mm-long silicone tube containing 10 μL type I collagen and used to create an IPJG between the facial nerve trunk and the hypoglossal nerve (the silicone tube group). Thirteen weeks after the surgery, the outcome was histologically and physiologically compared with conventional IPJG with autograft using the great auricular nerve. Results: Retrograde tracer test confirmed a double innervation by the facial and hypoglossal nerve nuclei. In the autograft and silicone tube groups, the regeneration of myelinated axons was observed. Conclusion: In this study, the authors successfully developed an end-to-side neurorrhaphy technique with the recipient nerve and an artificial nerve conduit, and revealed that an IPJG in the conduit was effective in the rat facial nerve paresis model. PMID:26180717

  7. The effect of tendon excursion velocity on longitudinal median nerve displacement: differences between carpal tunnel syndrome patients and controls.

    PubMed

    Filius, Anika; Thoreson, Andrew R; Wang, Yuexiang; Passe, Sandra M; Zhao, Chunfeng; An, Kai-Nan; Amadio, Peter C

    2015-04-01

    The subsynovial connective tissue (SSCT) is a viscoelastic structure connecting the median nerve (MN) and the flexor tendons in the carpal tunnel. Increased strain rates increases stiffness in viscoelastic tissues, and thereby its capacity to transfer shear load. Therefore, tendon excursion velocity may impact the MN displacement. In carpal tunnel syndrome (CTS) the SSCT is fibrotic and may be ruptured, and this may affect MN motion. In this study, ultrasonography was performed on 14 wrists of healthy controls and 25 wrists of CTS patients during controlled finger motions performed at three different velocities. Longitudinal MN and tendon excursion were assessed using a custom speckle tracking algorithm and compared across the three different velocities. CTS patients exhibited significantly less MN motion than controls (p ≤ 0.002). While in general, MN displacement increased with increasing tendon excursion velocity (p ≤ 0.031). These findings are consistent with current knowledge of SSCT mechanics in CTS, in which in some patients the fibrotic SSCT appears to have ruptured from the tendon surface. PMID:25640903

  8. Diagnostic Significance of Ultrasonographic Measurements and Median-Ulnar Ratio in Carpal Tunnel Syndrome: Correlation with Nerve Conduction Studies

    PubMed Central

    Mesci, Nilgün; Çetinkaya, Yilmaz; Geler Külcü, Duygu

    2016-01-01

    Background and Purpose We determined the reliability of ultrasonography (US) measurements for diagnosing carpal tunnel syndrome (CTS) and their correlation with symptom duration and electrophysiology findings. We determined whether the ratio of the median-to-ulnar cross-sectional areas (CSAs) can support CTS diagnoses. Methods The pisiform CSA (CSApisiform), swelling ratio (SR), palmar bowing, and CSApisiform/ulnar CSA (CSAulnar) measurements made in two subgroups of CTS patients (having sensory affection alone or having both sensory and motor affection) were compared with controls. CSAulnar was measured in Guyon's canal at the level of most-protuberant portion of the pisiform bone. Results The values of all of the measured US parameters were higher in patients with CTS (n=50) than in controls (n=62). CSApisiform could be used to diagnose CTS of mild severity. All of the parameters were positively correlated with the distal latency of the compound muscle action potential, and all of them except for SR were negatively correlated with the sensory nerve conduction velocity. A CSApisiform/CSAulnar ratio of ≥1.79 had a sensitivity of 70% and a specificity of 76% for diagnosing CTS. Conclusions Only CSApisiform measurements were reliable for diagnosing early stages of CTS, and CSApisiform/CSAulnar had a lower diagnostic value for diagnosing CTS. PMID:27095524

  9. Neuromuscular electrical stimulation of the median nerve facilitates low motor cortex excitability in patients with spinocerebellar ataxia.

    PubMed

    Chen, Chih-Chung; Chuang, Yu-Fen; Yang, Hsiao-Chu; Hsu, Miao-Ju; Huang, Ying-Zu; Chang, Ya-Ju

    2015-02-01

    The neuromodulation of motor excitability has been shown to improve functional movement in people with central nervous system damage. This study aimed to investigate the mechanism of peripheral neuromuscular electrical stimulation (NMES) in motor excitability and its effects in people with spinocerebellar ataxia (SCA). This single-blind case-control study was conducted on young control (n=9), age-matched control (n=9), and SCA participants (n=9; 7 SCAIII and 2 sporadic). All participants received an accumulated 30 min of NMES (25 Hz, 800 ms on/800 ms off) of the median nerve. The central motor excitability, measured by motor evoked potential (MEP) and silent period, and the peripheral motor excitability, measured by the H-reflex and M-wave, were recorded in flexor carpi radialis (FCR) muscle before, during, and after the NMES was applied. The results showed that NMES significantly enhanced the MEP in all 3 groups. The silent period, H-reflex and maximum M-wave were not changed by NMES. We conclude that NMES enhances low motor excitability in patients with SCA and that the mechanism of the neuromodulation was supra-segmental. These findings are potentially relevant to the utilization of NMES for preparation of motor excitability. The protocol was registered at Clinicaltrials.gov (NCT02103075). PMID:25434572

  10. Median nerve fascicle transfer versus ulnar nerve fascicle transfer to the biceps motor branch in C5-C6 and C5-C7 brachial plexus injuries: nonrandomized prospective study of 23 consecutive patients.

    PubMed

    Cho, Alvaro Baik; Paulos, Renata Gregorio; de Resende, Marcelo Rosa; Kiyohara, Leandro Yoshinobu; Sorrenti, Luiz; Wei, Teng Hsiang; Bolliger Neto, Raul; Mattar Júnior, Rames

    2014-10-01

    The purpose of this study was to observe whether the results of the median nerve fascicle transfer to the biceps are equivalent to the classical ulnar nerve fascicle transfer, in terms of elbow flexion strength and donor nerve morbidity. Twenty-five consecutive patients were operated between March 2007 and July 2013. The patients were divided into two groups. In Group 1 (n = 8), the patients received an ulnar nerve fascicle transfer to the biceps motor branch. In Group 2 (n = 15), the patients received a median nerve fascicle transfer to the biceps motor branch. Two patients with follow-up less than six months were excluded. Both groups were similar regarding age (P = 0.070), interval of injury (P = 0.185), and follow-up period (P = 0.477). Elbow flexion against gravity was achieved in 7 of 8 (87.5%) patients in Group 1, versus 14 of 15 (93.3%) patients in Group 2 (P = 1.000). The level of injury (C5-C6 or C5-C7) did not affect anti-gravity elbow flexion recovery in both the groups (P = 1.000). It was concluded that the median nerve fascicle transfer to the biceps is as good as the ulnar nerve fascicle transfer, even in C5-C7 injuries. PMID:24753064

  11. Repeatability and Minimal Detectable Change in Longitudinal Median Nerve Excursion Measures During Upper Limb Neurodynamic Techniques in a Mixed Population: A Pilot Study Using Musculoskeletal Ultrasound Imaging.

    PubMed

    Paquette, Philippe; Lamontagne, Martin; Higgins, Johanne; Gagnon, Dany H

    2015-07-01

    This study determined test-retest reliability and minimum detectable change in longitudinal median nerve excursion during upper limb neurodynamic tests (ULNTs). Seven participants with unilateral or bilateral carpal tunnel syndrome and 11 healthy participants were randomly tested with two ULNTs (i.e., tensioner and slider). Each ULNT was performed three times each at 45° and 90° of shoulder abduction on two separate visits. Video sequences of median nerve excursion, recorded by a physical therapist using ultrasound imaging, were quantified using computer software. The generalizability theory, encompassing a G-Study and a D-study, measured the dependability coefficient (Φ) along with standard error of measurement (SEM) accuracy and allowed various testing protocols to be proposed. The highest reliability (Φ = 0.84) and lowest minimal measurement error (SEM = 0.58 mm) of the longitudinal median nerve excursion were reached during the ULNT-slider performed with 45° of shoulder abduction and when measures obtained from three different image sequences recorded during a single visit were averaged. It is recommended that longitudinal median nerve excursion measures computed from three separate image sequences recorded during a single visit be averaged in clinical practice. Ideally, adding a second visit (six image sequences) is also suggested in research protocols. PMID:25868536

  12. Comparison of divided sciatic nerve growth within dermis, venous and nerve graft conduit in rat

    PubMed Central

    Fatemi, Mohammad Javad; Foroutan, Kamal Seyed; Ashtiani, Abass Kazemi; Mansoori, Maryam Jafari; Vaghardoost, Reza; Pedram, Sepehr; Hosseinpolli, Aidin; Rajabi, Fatemeh; Mousavi, Seyed Jaber

    2010-01-01

    BACKGROUND: Considering the common origin of skin and peripheral nervous system, a tube of dermal layer of skin hypothetically can be an ideal conduit for nerve reconstruction. An experimental study performed to evaluate the nerve regeneration of efficacy into a dermal tube. METHODS: Sixty male Wistar rats were used. A 10 mm gap was produced in right sciatic nerves. In group A the autogenous nerve grafts were used to bridge the defects. In group B vein conduit were use to reconstruct the gaps. In group C dermal tube were used to bridge the defects. Morphologic studies were carried out after 3 month. RESULTS: The density of nerve fibers was significantly higher in autogenous nerve graft group. The efficacy of nerve growth into the dermal tube group was significantly poor in comparison to other groups. CONCLUSIONS: In the present study, dermis was used as the nerve conduit for the first time. This study indicates that the dermal tube is not a suitable conduit for nerve regeneration till further studies to resolve the problems before clinical application. PMID:21526083

  13. The Prevalence of Anatomical Variations of the Median Nerve in the Carpal Tunnel: A Systematic Review and Meta-Analysis

    PubMed Central

    Roy, Joyeeta; Vikse, Jens; Ramakrishnan, Piravin Kumar; Walocha, Jerzy A.; Tomaszewski, Krzysztof A.

    2015-01-01

    Background and Objective The course and branches of the median nerve (MN) in the wrist vary widely among the population. Due to significant differences in the reported prevalence of such variations, extensive knowledge on the anatomy of the MN is essential to avoid iatrogenic nerve injury. Our aim was to determine the prevalence rates of anatomical variations of the MN in the carpal tunnel and the most common course patterns and variations in its thenar motor branch (TMB). Study Design A systematic search of all major databases was performed to identify articles that studied the prevalence of MN variations in the carpal tunnel and the TMB. No date or language restrictions were set. Extracted data was classified according to Lanz's classification system: variations in the course of the single TMB—extraligamentous, subligamentous, and transligamentous (type 1); accessory branches of the MN at the distal carpal tunnel (type 2); high division of the MN (type 3); and the MN and its accessory branches proximal to the carpal tunnel (type 4). Pooled prevalence rates were calculated using MetaXL 2.0. Results Thirty-one studies (n = 3918 hands) were included in the meta-analysis. The pooled prevalence rates of the extraligamentous, subligamentous, and transligamentous courses were 75.2% (95%CI:55.4%-84.7%), 13.5% (95%CI:3.6%-25.7%), and 11.3% (95%CI:2.4%-23.0%), respectively. The prevalence of Lanz group 2, 3, and 4 were 4.6% (95%CI:1.6%-9.1%), 2.6% (95%CI:0.1%-2.8%), and 2.3% (95%CI:0.3%-5.6%), respectively. Ulnar side of branching of the TMB was found in 2.1% (95%CI:0.9%-3.6%) of hands. The prevalence of hypertrophic thenar muscles over the transverse carpal ligament was 18.2% (95%CI:6.8%-33.0%). A transligamentous course of the TMB was more commonly found in hands with hypertrophic thenar muscles (23.4%, 95%CI:5.0%-43.4%) compared to those without hypertrophic musculature (1.7%, 95%CI:0%-100%). In four studies (n = 423 hands), identical bilateral course of the TMB was

  14. Transverse Movement of the Median Nerve in the Carpal Tunnel during Wrist and Finger Motion in Patients with Carpal Tunnel Syndrome.

    PubMed

    Nanno, Mitsuhiko; Sawaizumi, Takuya; Kodera, Norie; Tomori, Yuji; Takai, Shinro

    2015-01-01

    Carpal tunnel syndrome (CTS) is the most common peripheral compression neuropathy of the upper extremity. Repetitive wrist and finger motion has been suggested as a major factor of pathogenesis of CTS. However, little is known about the pathomechanics of CTS. We aimed to evaluate the movement of the median nerve in the carpal tunnel during wrist and finger motions using transverse ultrasound in 21 patients with CTS (5 men and 16 women with mean age 69.0 years). We examined quantitatively the median nerve location as a coordinate within the carpal tunnel at varied wrist positions with all fingers full extension and flexion respectively in the affected and unaffected sides. We thus found that at all wrist positions during finger motion, the median nerve moved significantly more ulnopalmarly in the affected side compared to the unaffected side (p < 0.05). Especially, at the wrist palmar-flexion position as a provocative test, the nerve moved significantly (p < 0.05) the most ulnopalmarly among all wrist positions in the affected side. The nerve was the most strongly compressed against the transverse carpal ligament by the flexor tendons. Additionally, the displacement amount of the nerve in the dorsal-palmar direction was significantly smaller in the affected side than in the unaffected side. These findings indicate that such a pattern of nerve movement has the potential to distinguish affected from unaffected individuals. This ultrasound information could be useful in better understanding of the pathomechanics of CTS, and in further improvement of diagnosis and treatment for CTS. PMID:26133190

  15. Centrally administered glucagon stimulates sympathetic nerve activity in rat.

    PubMed

    Krzeski, R; Czyzyk-Krzeska, M F; Trzebski, A; Millhorn, D E

    1989-12-18

    The effect of pancreatic glucagon given intravenously, intracerebroventricularly and microinjected into the nucleus of the solitary tract on sympathetic activity in the cervical trunk and adrenal nerve was examined in rat. In each case glucagon caused a relatively long-lasting substantial increase in discharge of both nerves. This finding shows that glucagon can act centrally to stimulate sympathetic activity. The most probable site for the sympathoexcitatory effect of glucagon is the nucleus of the solitary tract. PMID:2598031

  16. Electrical stimulation accelerates nerve regeneration and functional recovery in delayed peripheral nerve injury in rats.

    PubMed

    Huang, Jinghui; Zhang, Yongguang; Lu, Lei; Hu, Xueyu; Luo, Zhuojing

    2013-12-01

    The present study aims to investigate the potential of brief electrical stimulation (ES; 3 V, 20 Hz, 20 min) in improving functional recovery in delayed nerve injury repair (DNIR). The sciatic nerve of Sprague Dawley rats was transected, and the repair of nerve injury was delayed for different time durations (2, 4, 12 and 24 weeks). Brief depolarizing ES was applied to the proximal nerve stump when the transected nerve stumps were bridged with a hollow nerve conduit (5 mm in length) after delayed periods. We found that the diameter and number of regenerated axons, the thickness of myelin sheath, as well as the number of Fluoro-Gold retrograde-labeled motoneurons and sensory neurons were significantly increased by ES, suggesting that brief ES to proximal nerve stumps is capable of promoting nerve regeneration in DNIR with different delayed durations, with the longest duration of 24 weeks. In addition, the amplitude of compound muscle action potential (gastrocnemius muscle) and nerve conduction velocity were also enhanced, and gastrocnemius muscle atrophy was partially reversed by brief ES, indicating that brief ES to proximal nerve stump was able to improve functional recovery in DNIR. Furthermore, brief ES was capable of increasing brain-derived neurotrophic factor (BDNF) expression in the spinal cord in DNIR, suggesting that BDNF-mediated neurotrophin signaling might be one of the contributing factors to the beneficial effect of brief ES on DNIR. In conclusion, the present findings indicate the potential of using brief ES as a useful method to improve functional recovery for delayed repair of peripheral nerve lesions. PMID:24118464

  17. Effect of Frankincense Extract on Nerve Recovery in the Rat Sciatic Nerve Damage Model

    PubMed Central

    Jiang, Xiaowen; Ma, Jun; Wei, Qingwei; Feng, Xinxin; Qiao, Lu; Liu, Lin; Zhang, Binqing; Yu, Wenhui

    2016-01-01

    This study investigated the effect of frankincense extract on peripheral nerve regeneration in a crush injury rat model. Forty-eight Sprague-Dawley rats were randomly divided into four groups: control and frankincense extract low-, medium-, and high-dose groups. At days 7, 14, 21, and 28 following the surgery, nerve regeneration and functional recovery were evaluated using the sciatic functional index (SFI), expression of GAP-43, and the proliferation of Schwann cells (SCs) in vivo and in vitro. At day 7, the SFI in the frankincense extract high-dose group was significantly improved compared with the control group. After day 14, SFI was significantly improved in the medium- and high-dose groups. There was no significant difference in GAP-43 expression among the groups at day 7. However, after day 14, expression of GAP-43 in the high-dose group was higher than that in the control group. Histological evaluation showed that the injured nerve of frankincense extract high-dose group recovered better than the other groups 28 days after surgery. Further, S100 immunohistochemical staining, MTT colorimetry, and flow cytometry assays all showed that frankincense extract could promote the proliferation of SCs. In conclusion, frankincense extract is able to promote sciatic nerve regeneration and improve the function of a crushed sciatic nerve. This study provides a new direction for the repair of peripheral nerve injury. PMID:27143985

  18. Cortical plasticity induced by different degrees of peripheral nerve injuries: a rat functional magnetic resonance imaging study under 9.4 Tesla

    PubMed Central

    2013-01-01

    Background Major peripheral nerve injuries not only result in local deficits but may also cause distal atrophy of target muscles or permanent loss of sensation. Likewise, these injuries have been shown to instigate long-lasting central cortical reorganization. Methods Cortical plasticity changes induced after various types of major peripheral nerve injury using an electrical stimulation technique to the rat upper extremity and functional magnetic resonance imaging (fMRI) were examined. Studies were completed out immediately after injury (acute stage) and at two weeks (subacute stage) to evaluate time affect on plasticity. Results After right-side median nerve transection, cortical representation of activation of the right-side ulnar nerve expanded intra-hemispherically into the cortical region that had been occupied by the median nerve representation After unilateral transection of both median and ulnar nerves, cortical representation of activation of the radial nerve on the same side of the body also demonstrated intra-hemispheric expansion. However, simultaneous electrical stimulation of the contralateral uninjured median and ulnar nerves resulted in a representation that had expanded both intra- and inter-hemispherically into the cortical region previously occupied by the two transected nerve representations. Conclusions After major peripheral nerve injury, an adjacent nerve, with similar function to the injured nerve, may become significantly over-activated in the cortex when stimulated. This results in intra-hemispheric cortical expansion as the only component of cortical plasticity. When all nerves responsible for a certain function are injured, the same nerves on the contralateral side of the body are affected and become significantly over-activated during a task. Both intra- and inter-hemispheric cortical expansion exist, while the latter dominates cortical plasticity. PMID:23659705

  19. Mandibular Branch of the Facial Nerve in Wistar Rats: New Experimental Model to Assess Facial Nerve Regeneration

    PubMed Central

    Bento, Ricardo Ferreira; Salomone, Raquel; Nascimento, Silvia Bona do; Ferreira, Ricardo Jose Rodriguez; Silva, Ciro Ferreira da; Costa, Heloisa Juliana Zabeu Rossi

    2014-01-01

    Introduction The ideal animal model for nerve regeneration studies is the object of controversy, because all models described by the literature have advantages and disadvantages. Objective To describe the histologic and functional patterns of the mandibular branch of the facial nerve of Wistar rats to create a new experimental model of facial nerve regeneration. Methods Forty-two male rats were submitted to a nerve conduction test of the mandibular branch to obtain the compound muscle action potential. Twelve of these rats had the mandibular branch surgically removed and submitted to histologic analysis (number, partial density, and axonal diameter) of the proximal and distal segments. Results There was no statistically significant difference in the functional and histologic variables studied. Conclusion These new histologic and functional standards of the mandibular branch of the facial nerve of rats establish an objective, easy, and greatly reproducible model for future facial nerve regeneration studies. PMID:25992106

  20. Mandibular branch of the facial nerve in wistar rats: new experimental model to assess facial nerve regeneration.

    PubMed

    Bento, Ricardo Ferreira; Salomone, Raquel; Nascimento, Silvia Bona do; Ferreira, Ricardo Jose Rodriguez; Silva, Ciro Ferreira da; Costa, Heloisa Juliana Zabeu Rossi

    2014-07-01

    Introduction The ideal animal model for nerve regeneration studies is the object of controversy, because all models described by the literature have advantages and disadvantages. Objective To describe the histologic and functional patterns of the mandibular branch of the facial nerve of Wistar rats to create a new experimental model of facial nerve regeneration. Methods Forty-two male rats were submitted to a nerve conduction test of the mandibular branch to obtain the compound muscle action potential. Twelve of these rats had the mandibular branch surgically removed and submitted to histologic analysis (number, partial density, and axonal diameter) of the proximal and distal segments. Results There was no statistically significant difference in the functional and histologic variables studied. Conclusion These new histologic and functional standards of the mandibular branch of the facial nerve of rats establish an objective, easy, and greatly reproducible model for future facial nerve regeneration studies. PMID:25992106

  1. Histochemical discrimination of fibers in regenerating rat infraorbital nerve

    NASA Technical Reports Server (NTRS)

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

    1992-01-01

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

  2. Nerve Growth Factor Decreases in Sympathetic and Sensory Nerves of Rats with Chronic Heart Failure

    PubMed Central

    Lu, Jian

    2014-01-01

    Nerve growth factor (NGF) plays a critical role in the maintenance and survival of both sympathetic and sensory nerves. Also, NGF can regulate receptor expression and neuronal activity in the sympathetic and sensory neurons. Abnormalities in NGF regulation are observed in patients and animals with heart failure (HF). Nevertheless, the effects of chronic HF on the levels of NGF within the sympathetic and sensory nerves are not known. Thus, the ELISA method was used to assess the levels of NGF in the stellate ganglion (SG) and dorsal root ganglion (DRG) neurons of control rats and rats with chronic HF induced by myocardial infarction. Our data show for the first time that the levels of NGF were significantly decreased (P < 0.05) in the SG and DRG neurons 6–20 weeks after ligation of the coronary artery. In addition, a close relation was observed between the NGF levels and the left ventricular function. In conclusion, chronic HF impairs the expression of NGF in the sympathetic and sensory nerves. Given that sensory afferent nerves are engaged in the sympathetic nervous responses to somatic stimulation (i.e. muscle activity during exercise) via a reflex mechanism, our data indicate that NGF is likely responsible for the development of muscle reflex-mediated abnormal sympathetic responsiveness observed in chronic HF. PMID:24913185

  3. Variable spatial magnetic field influences peripheral nerves regeneration in rats.

    PubMed

    Suszyński, Krzysztof; Marcol, Wiesław; Szajkowski, Sebastian; Pietrucha-Dutczak, Marita; Cieślar, Grzegorz; Sieroń, Aleksander; Lewin-Kowalik, Joanna

    2014-09-01

    Generator of spatial magnetic field is one of most recent achievements among the magnetostimulators. This apparatus allows to obtain the rotating magnetic field. This new method may be more effective than other widely used techniques of magnetostimulation and magnetotherapy. We investigated the influence of alternating, spatial magnetic field on the regeneration of the crushed rat sciatic nerves. Functional and morphological evaluations were used. After crush injury of the right sciatic nerve, Wistar C rats (n = 80) were randomly divided into four groups (control and three experimental). The experimental groups (A, B, C) were exposed (20 min/day, 5 d/week, 4 weeks) to alternating spatial magnetic field of three different intensities. Sciatic Functional Index (SFI) and tensometric assessments were performed every week after nerve crush. Forty-eight hours before the sacrificing of animals, DiI (1,1'-di-octadecyl-3,3,3',3'-tetramethyloindocarbocyanine perchlorate) was applied 5 mm distally to the crush site. Collected nerves and dorsal root ganglia (DRG) were subjected to histological and immunohistochemical staining. The survival rate of DRG neurons was estimated. Regrowth and myelination of the nerves was examined. The results of SFI and tensometric assessment showed improvement in all experimental groups as compared to control, with best outcome observed in group C, exposed to the strongest magnetic field. In addition, DRG survival rate and nerve regeneration intensity were significantly higher in the C group. Above results indicate that strong spatial alternating magnetic field exerts positive effect on peripheral nerve regeneration and its application could be taken under consideration in the therapy of injured peripheral nerves. PMID:23781984

  4. [The hypertensive effect of vasopressin administered into the median eminence of the hypothalamus in rats].

    PubMed

    Gindeva, R; Pencheva, T

    1991-01-01

    Data about direct effect of vasopressin (VP) on the central arterial pressure (AP) orientated us to investigate the effect of its local administration in the median eminence (ME) of the hypothalamus in rats. For this purpose VP was administered in ME under micropellet form. AP was measured indirectly on the tail of rats up to 96th hour after operation. After implantation of VP there was an elevation of AP with maximum in the first hour, which was statistically significant (p less than 0.01). Identical manipulation (sham operation) was performed to control the lesion effect. Transitory lowering of AP with maximum in the first hour was also established and it was statistically significant (p less than 0.001), For exclusion a nonspecific systemic effect of VP the same dose was administered in the parietal cortex, during which transitory and short-lasting reaction occurred in the first hour after the operation. The data indicate that the peptide, administered in ME under micropellet form, could induce a longlasting hypertensive effect. PMID:1884687

  5. Effects of 90 min of manual repetitive work on skin temperature and median and ulnar nerve conduction parameters: a pilot study in normal subjects.

    PubMed

    Bonfiglioli, Roberta; Mussoni, Patrizia; Graziosi, Francesca; Calabrese, Monica; Farioli, Andrea; Marinelli, Francesco; Violante, Francesco S

    2013-02-01

    To test whether the influence of manual activity should be considered when interpreting the results of nerve conduction study (NCS) of the upper limbs performed during work shifts, we evaluated the short-term effect of 90-min repetitive manual work on NCS parameters. Twenty-eight healthy volunteers underwent NCS of the dominant limb at the end of an interview (T(0)), after a 30-min rest in sitting position (T(1)) and after performing a standardized 90-min manual task (T(2)). The task was designed to simulate typical assembly and packing activities. No significant differences were observed for skin temperature (Ts) and NCS parameters between T(0) and T(1). Significantly (p < 0.001) higher Ts mean values were found at T(2) as compared to the previous tests for both females and males. The regression analysis showed an association between temperature variation and nerve conduction velocity values for the median and ulnar nerve at T(2) as compared to T(1). In females, a reduction of the mean sensory nerve action potential (SNAP) amplitude at T(2) was recorded, whereas an opposite trend was observed among males. Manual work is able to influence hand Ts and to modify NCS parameters. SNAP amplitudes changes suggest gender differences in peripheral nerve characteristics that deserve further investigation. PMID:23063257

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

    PubMed Central

    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.

    2008-01-01

    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. PMID:17969116

  7. (-)-Epigallocatechin-3-gallate (EGCG) attenuates peripheral nerve degeneration in rat sciatic nerve crush injury.

    PubMed

    Renno, Waleed M; Al-Maghrebi, May; Alshammari, Ahmad; George, Preethi

    2013-02-01

    Recently, we have shown that green tea (GT) consumption improves both reflexes and sensation in unilateral chronic constriction injury to the sciatic nerve. Considering the substantial neuroprotective properties of GT polyphenols, we sought to investigate whether (-)-epigallocatechin-3-gallate (EGCG) could protect the sciatic nerve and improve functional impairments induced by a crushing injury. We also examined whether neuronal cell apoptosis induced by the crushing injury is affected by EGCG treatment. Histological examination of sciatic nerves from EGCG-treated (50mg/kg; i.p.) showed that axonotmized rats had a remarkable axonal and myelin regeneration with significant decrease in the number of myelinated axonal fibers compared to vehicle-treated crush group. Similarly, ultrastructural evaluation of EGCG-treated nerves displayed normal unmyelinated and myelinated axons with regular myelin sheath thickness and normalized appearance of Schmidt-Lantermann clefts. Extracellular matrix displayed normal collagen fibers appearance with distinctively organized distribution similar to sham animals. Analysis of foot position and extensor postural thrust test showed a progressive and faster recovery in the EGCG-treated group compared to vehicle-treated animals. EGCG-treated rats showed significant increase in paw withdrawal thresholds to mechanical stimulation compared to vehicle-treated crush group. EGCG treatment also restored the mRNA expression of Bax, Bcl-2 and survivin but not that of p53 to sham levels on days 3 and 7 post-injury. Our results demonstrate that EGCG treatment enhanced functional recovery, advanced morphological nerve rescue and accelerated nerve regeneration following crush injury partly due to the down regulation of apoptosis related genes. PMID:23313191

  8. Multidimensional ultrasound imaging of the wrist: Changes of shape and displacement of the median nerve and tendons in carpal tunnel syndrome.

    PubMed

    Filius, Anika; Scheltens, Marjan; Bosch, Hans G; van Doorn, Pieter A; Stam, Henk J; Hovius, Steven E R; Amadio, Peter C; Selles, Ruud W

    2015-09-01

    Dynamics of structures within the carpal tunnel may alter in carpal tunnel syndrome (CTS) due to fibrotic changes and increased carpal tunnel pressure. Ultrasound can visualize these potential changes, making ultrasound potentially an accurate diagnostic tool. To study this, we imaged the carpal tunnel of 113 patients and 42 controls. CTS severity was classified according to validated clinical and nerve conduction study (NCS) classifications. Transversal and longitudinal displacement and shape (changes) were calculated for the median nerve, tendons and surrounding tissue. To predict diagnostic value binary logistic regression modeling was applied. Reduced longitudinal nerve displacement (p≤ 0.019), increased nerve cross-sectional area (p≤ 0.006) and perimeter (p≤ 0.007), and a trend of relatively changed tendon displacements were seen in patients. Changes were more convincing when CTS was classified as more severe. Binary logistic modeling to diagnose CTS using ultrasound showed a sensitivity of 70-71% and specificity of 80-84%. In conclusion, CTS patients have altered dynamics of structures within the carpal tunnel. PMID:25865180

  9. Carpal Tunnel Syndrome Assessment with Ultrasonography: Value of Inlet-to-Outlet Median Nerve Area Ratio in Patients versus Healthy Volunteers

    PubMed Central

    Liu, Fang; Zhu, Jiaan; Ye, Dongmei; Feng, Xianxuan; Xu, Yiming; Wang, Gang; Bai, Yuehong

    2015-01-01

    Objective To evaluate the diagnostic value of the Inlet-to-outlet median nerve area ratio (IOR) in patients with clinically and electrophysiologically confirmed carpal tunnel syndrome (CTS). Methods Forty-six wrists in 46 consecutive patients with clinical and electrodiagnostic evidence of CTS and forty-four wrists in 44 healthy volunteers were examined with ultrasonography. The cross-sectional area (CSA) of the median nerve was measured at the carpal tunnel inlet (the level of scaphoid-pisiform) and outlet (the level of the hook of the hamate), and the IOR was calculated for each wrist. Ultrasonography and electrodiagnostic tests were performed under blinded conditions. Electrodiagnostic testing combined with clinical symptoms were considered to be the gold standard test. Receiver operating characteristic (ROC) curves were used to evaluate the diagnostic value between the inlet CSA and IOR. Results The study population included 16 men and 30 women (mean age, 45.3 years; range, 18–83 years). The control population included 18 men and 26 women (mean age, 50.4 years; range, 18–79 years). The mean inlet CSA was 8.7 mm2 in healthy controls and 14.6mm2 in CTS group (P<0.001). The mean IOR in healthy volunteers (1.0) was smaller than that in patients (1.6, P<0.001). Receiver operating characteristic analysis revealed a diagnostic advantage to using the IOR rather than the inlet CSA (P<0.01). An IOR cutoff value of ≥ 1.3 would yield 93% specificity and 91% sensitivity in the diagnosis of CTS. Conclusion The IOR of median nerve area promises to be an effective means in the diagnosis of CTS. A large-scale, randomized controlled trial is required to determine how and when this parameter will be used. PMID:25617835

  10. Low-intensity pulsed ultrasound accelerates nerve regeneration following inferior alveolar nerve transection in rats.

    PubMed

    Sato, Mai; Motoyoshi, Mitsuru; Shinoda, Masamichi; Iwata, Koichi; Shimizu, Noriyoshi

    2016-06-01

    Inferior alveolar nerve (IAN) injury, which is frequently caused by orofacial surgery or trauma, induces sensory loss in orofacial regions innervated by the IAN. However, no effective treatment for orofacial sensory loss currently exists. We determined whether sensory loss in facial skin above the mental foramen following IAN transection was recovered by exposure of the transected IAN to low-intensity pulsed ultrasound (LIPUS). Inferior alveolar nerve transection (IANX) was performed in 7-wk-old male Sprague-Dawley rats. On day 7 after IANX, the effect of daily LIPUS (from day 0) on the transected IAN, in terms of sensitivity to mechanical stimulation of the facial skin above the mental foramen, was examined. Moreover, the number of trigeminal ganglion (TG) neurons innervating the facial skin above the mental foramen of rats with IANX treated daily with LIPUS was counted using the retrograde neurotracing technique. Daily exposure of the transected IAN to LIPUS significantly promoted recovery of the head-withdrawal threshold in response to mechanical stimulation of the facial skin above the mental foramen, and the number of TG neurons innervating the facial skin above mental foramen was significantly increased in rats with IANX treated daily with LIPUS compared with sham or LIPUS-unexposed rats. Daily treatment of stumps of the transected IAN with LIPUS facilitated morphological and functional regeneration, suggesting that LIPUS is an effective and novel therapy for IAN injury. PMID:27058986

  11. Sciatic nerve regeneration in rats by a promising electrospun collagen/poly(ε-caprolactone) nerve conduit with tailored degradation rate

    PubMed Central

    2011-01-01

    Background To cope with the limitations faced by autograft acquisitions particularly for multiple nerve injuries, artificial nerve conduit has been introduced by researchers as a substitute for autologous nerve graft for the easy specification and availability for mass production. In order to best mimic the structures and components of autologous nerve, great efforts have been made to improve the designation of nerve conduits either from materials or fabrication techniques. Electrospinning is an easy and versatile technique that has recently been used to fabricate fibrous tissue-engineered scaffolds which have great similarity to the extracellular matrix on fiber structure. Results In this study we fabricated a collagen/poly(ε-caprolactone) (collagen/PCL) fibrous scaffold by electrospinning and explored its application as nerve guide substrate or conduit in vitro and in vivo. Material characterizations showed this electrospun composite material which was made of submicron fibers possessed good hydrophilicity and flexibility. In vitro study indicated electrospun collagen/PCL fibrous meshes promoted Schwann cell adhesion, elongation and proliferation. In vivo test showed electrospun collagen/PCL porous nerve conduits successfully supported nerve regeneration through an 8 mm sciatic nerve gap in adult rats, achieving similar electrophysiological and muscle reinnervation results as autografts. Although regenerated nerve fibers were still in a pre-mature stage 4 months postoperatively, the implanted collagen/PCL nerve conduits facilitated more axons regenerating through the conduit lumen and gradually degraded which well matched the nerve regeneration rate. Conclusions All the results demonstrated this collagen/PCL nerve conduit with tailored degradation rate fabricated by electrospinning could be an efficient alternative to autograft for peripheral nerve regeneration research. Due to its advantage of high surface area for cell attachment, it is believed that this

  12. Low-level laser irradiation improves functional recovery and nerve regeneration in sciatic nerve crush rat injury model.

    PubMed

    Wang, Chau-Zen; Chen, Yi-Jen; Wang, Yan-Hsiung; Yeh, Ming-Long; Huang, Mao-Hsiung; Ho, Mei-Ling; Liang, Jen-I; Chen, Chia-Hsin

    2014-01-01

    The development of noninvasive approaches to facilitate the regeneration of post-traumatic nerve injury is important for clinical rehabilitation. In this study, we investigated the effective dose of noninvasive 808-nm low-level laser therapy (LLLT) on sciatic nerve crush rat injury model. Thirty-six male Sprague Dawley rats were divided into 6 experimental groups: a normal group with or without 808-nm LLLT at 8 J/cm(2) and a sciatic nerve crush injury group with or without 808-nm LLLT at 3, 8 or 15 J/cm(2). Rats were given consecutive transcutaneous LLLT at the crush site and sacrificed 20 days after the crush injury. Functional assessments of nerve regeneration were analyzed using the sciatic functional index (SFI) and hindlimb range of motion (ROM). Nerve regeneration was investigated by measuring the myelin sheath thickness of the sciatic nerve using transmission electron microscopy (TEM) and by analyzing the expression of growth-associated protein 43 (GAP43) in sciatic nerve using western blot and immunofluorescence staining. We found that sciatic-injured rats that were irradiated with LLLT at both 3 and 8 J/cm(2) had significantly improved SFI but that a significant improvement of ROM was only found in rats with LLLT at 8 J/cm(2). Furthermore, the myelin sheath thickness and GAP43 expression levels were significantly enhanced in sciatic nerve-crushed rats receiving 808-nm LLLT at 3 and 8 J/cm(2). Taken together, these results suggest that 808-nm LLLT at a low energy density (3 J/cm(2) and 8 J/cm(2)) is capable of enhancing sciatic nerve regeneration following a crush injury. PMID:25119457

  13. Characteristics of ejaculated rat semen after lesion of scrotal nerves.

    PubMed

    Garcia, Luis I; Soto-Cid, Abraham; Carrillo, Porfirio; Toledo, Rebeca; Hernandez, Maria Elena; Manzo, Jorge

    2007-05-16

    The scrotum, representing the pouch surrounding the testes and their associated structures, plays a significant role in maintaining the gonad at a temperature lower than that of the body. Although thermoregulation of the testes has been ascribed as a main function of the scrotum, here we found that mechanical stimulation of the scrotum is important during mating to facilitate the appropriate expulsion of semen during ejaculation. Previously we showed that the scrotal skin area is innervated by two nerve branches, the proximal (Psb) and distal (Dsb) scrotal branches which supply the proximal or distal half of the scrotum, respectively. The sensory field of each nerve is testosterone-dependent. The decreased androgen levels following castration reduce the sensitive area to mechanical stimuli that can be restored following exogenous administration of the hormone. Here, we tested the effect of scrotal nerve transection on sexual parameters of experienced male rats. Data show that lesion of PSb or DSb alone or combined did not affect the execution of sexual behavior. However, these lesions significantly reduced the proportion of males that expelled semen during ejaculation, with that semen showing a reduced quantity of sperm. Thus, scrotal nerves are important in reproduction not for the appropriate display of sexual behavior, but for the expulsion of a normal quantity of semen and number of sperm during ejaculation. Our suggestion is that scrotal afferents trigger spinal reflexes to activate autonomic efferents supplying the male reproductive tract for the control of seminal emission. PMID:17343882

  14. Behavioural and anatomical analysis of selective tibial nerve branch transfer to the deep peroneal nerve in the rat.

    PubMed

    Kemp, Stephen W P; Alant, Jacob; Walsh, Sarah K; Webb, Aubrey A; Midha, Rajiv

    2010-03-01

    Nerve transfer procedures involving the repair of a distal denervated nerve element with that of a foreign proximal nerve have become increasingly popular for clinical nerve repair as a surgical alternative to autologous nerve grafting. However, the functional outcomes and the central plasticity for these procedures remain poorly defined, particularly for a clinically relevant rodent model of hindlimb nerve transfer. We therefore evaluated the effect of selective tibial branch nerve transfer on behavioural recovery in animals following acute transection of the deep peroneal nerve. The results indicate that not only can hindlimb nerve transfers be successfully accomplished in a rat model but that these animals display a return of skilled locomotor function on a par with animals that underwent direct deep peroneal nerve repair (the current gold standard). At 2 months, ground reaction force analysis demonstrated that partial restoration of braking forces occurred in the nerve transfer group, whereas the direct repair group had fully restored these forces to similar to baseline levels. Ankle kinematic analysis revealed that only animals in the direct repair group significantly recovered flexion during the step cycle, indicating a recovery of surgically induced foot drop. Terminal electrophysiological and myological assessments demonstrated similar levels of reinnervation, whereas retrograde labelling studies confirmed that the peroneal nerve-innervated muscles were innervated by neurons from the tibial nerve pool in the nerve transfer group. Our results demonstrate a task-dependent recovery process, where skilled locomotor recovery is similar between nerve transfer and direct repair animals, whereas flat surface locomotion is significantly better in direct repair animals. PMID:20377620

  15. Diffusion tensor magnetic resonance imaging of regeneration/degeneration after rat sciatic nerve injury

    NASA Astrophysics Data System (ADS)

    Sig Hwang, Min; Perrin, George; Muir, David; Mareci, Thomas

    2005-11-01

    Diffusion tensor imaging was performed to investigate myelination and demyelination spatiotemporally in cut or crushed excised rat sciatic nerves in a 17.6 T magnet with a solenoid RF coil. Orientation independent measures of water diffusion, fractional anisotropy (FA) and averaged diffusivity (), were examined as MR parameters for the quantification of the myelin within the major peripheral nerve. Crushed nerves initially demonstrated decreased FA, followed by increase to FA of normal nerve with time. At 14 days post injury, FA of the nerve is high, 0.85, at the site proximal to the injury then FA decreases in a proximodistal gradient because the nerve remains more demyelinated toward the distal area. Cut sciatic nerves displayed a prolonged decrease of FA with time after injury. Also FA correlates with in these nerves. Therefore FA or may be a good indicator of myelination and demyelination in rat sciatic nerves and FA appears to be a more sensitive indicator of myelin.

  16. Low-Level Laser-Accelerated Peripheral Nerve Regeneration within a Reinforced Nerve Conduit across a Large Gap of the Transected Sciatic Nerve in Rats

    PubMed Central

    Shen, Chiung-Chyi; Yang, Yi-Chin; Huang, Tsung-Bin; Chan, Shiuh-Chuan; Liu, Bai-Shuan

    2013-01-01

    This study proposed a novel combination of neural regeneration techniques for the repair of damaged peripheral nerves. A biodegradable nerve conduit containing genipin-cross-linked gelatin was annexed using beta-tricalcium phosphate (TCP) ceramic particles (genipin-gelatin-TCP, GGT) to bridge the transection of a 15 mm sciatic nerve in rats. Two trigger points were irradiated transcutaneously using 660 nm of gallium-aluminum arsenide phosphide (GaAlAsP) via laser diodes for 2 min daily over 10 consecutive days. Walking track analysis showed a significant improvement in sciatic functional index (SFI) (P < 0.01) and pronounced improvement in the toe spreading ability of rats undergoing laser stimulation. Electrophysiological measurements (peak amplitude and area) illustrated by compound muscle action potential (CMAP) curves demonstrated that laser stimulation significantly improved nerve function and reduced muscular atrophy. Histomorphometric assessments revealed that laser stimulation accelerated nerve regeneration over a larger area of neural tissue, resulting in axons of greater diameter and myelin sheaths of greater thickness than that observed in rats treated with nerve conduits alone. Motor function, electrophysiological reactions, muscular reinnervation, and histomorphometric assessments all demonstrate that the proposed therapy accelerated the repair of transected peripheral nerves bridged using a GGT nerve conduit. PMID:23737818

  17. Pre-differentiation of mesenchymal stromal cells in combination with a microstructured nerve guide supports peripheral nerve regeneration in the rat sciatic nerve model.

    PubMed

    Boecker, Arne Hendrik; van Neerven, Sabien Geraldine Antonia; Scheffel, Juliane; Tank, Julian; Altinova, Haktan; Seidensticker, Katrin; Deumens, Ronald; Tolba, Rene; Weis, Joachim; Brook, Gary Anthony; Pallua, Norbert; Bozkurt, Ahmet

    2016-02-01

    Many bioartificial nerve guides have been investigated pre-clinically for their nerve regeneration-supporting function, often in comparison to autologous nerve transplantation, which is still regarded as the current clinical gold standard. Enrichment of these scaffolds with cells intended to support axonal regeneration has been explored as a strategy to boost axonal regeneration across these nerve guides Ansselin et al. (1998). In the present study, 20 mm rat sciatic nerve defects were implanted with a cell-seeded microstructured collagen nerve guide (Perimaix) or an autologous nerve graft. Under the influence of seeded, pre-differentiated mesenchymal stromal cells, axons regenerated well into the Perimaix nerve guide. Myelination-related parameters, like myelin sheath thickness, benefitted from an additional seeding with pre-differentiated mesenchymal stromal cells. Furthermore, both the number of retrogradely labelled sensory neurons and the axon density within the implant were elevated in the cell-seeded scaffold group with pre-differentiated mesenchymal stromal cells. However, a pre-differentiation had no influence on functional recovery. An additional cell seeding of the Perimaix nerve guide with mesenchymal stromal cells led to an extent of functional recovery, independent of the differentiation status, similar to autologous nerve transplantation. These findings encourage further investigations on pre-differentiated mesenchymal stromal cells as a cellular support for peripheral nerve regeneration. PMID:26296589

  18. Low-energy laser action on median and radial nerve post-traumatic lesion after surgical suture

    NASA Astrophysics Data System (ADS)

    Antipa, Ciprian; Bunila, Daniela; Crangulescu, Nicolae; Nacu, Mihaela; Podoleanu, Adrian Gh.; Stanciulescu, Viorica; Vasiliu, Virgil V.

    1996-01-01

    The low energy laser (LEL) biostimulatory effects on nervous tissue regeneration are well known. Thirty two patients with medial and/or radial nerve traumatic forearm lesion after surgical suture were divided into two groups: A-18 patients were treated with LEL; B-14 patients, witness, were treated with placebo lasers and classical medical and physical therapy. Lasers used were: HeNe, 632.5 nm wavelength, 2 mW power, and GaAlAs diode laser, 880 nm wavelength, pulsed emission with an output power 2 mW. Before, during, and after treatment EMG was done in order to measure objectively the efficiency of the treatment. We obtained good results after 4 - 5 months at 14 patients (77.7%) from group A and about the same results at 10 patients (71.3%) from group B, but after at least 8 months the good results were noticed concerning the improvements of EMG registration and on movements and force of the fingers. Finally we can say that the favorable results were obtained in at least twice shorter time with LEL treatment than with classical therapy.

  19. Immune cell distribution and immunoglobulin levels change following sciatic nerve injury in a rat model

    PubMed Central

    Yuan, Wei; Feng, Xinhong

    2016-01-01

    Objective(s): To investigate the systemic and local immune status of two surgical rat models of sciatic nerve injury, a crushed sciatic nerve, and a sciatic nerve transection Materials and Methods: Twenty-four adult male Sprague-Dawley rats were randomly divided into three groups: sham-operation (control group), sciatic nerve crush, and sciatic nerve transaction. Sciatic nerve surgery was performed. The percentage of CD4+ cells and the CD4+/CD8+ratio were determined by flow cytometry. Serum IgM and IgG levels were analyzed by ELISA. T-cells (CD3) and macrophages (CD68) in sciatic nerve tissue sections were identified through immunohistochemistry. Results: Compared to sham-operated controls, in rats that underwent nerve injury, the percentage of CD4+ cells and the CD4+/CD8+ ratio in the peripheral blood were significantly decreased 7 days after surgery, serum IgM levels were increased 14 days after surgery, and serum IgG levels were increased 21 days after surgery. There were a large number of CD3+ cells and a small number of CD68+ cells in sciatic nerve tissue sections 21 days after surgery, indicating T-cell and macrophage activation and infiltration. Local IgG deposition was also detected at the nerve injury site 21 days after surgery. Conclusion: Rat humoral and cellular immune status changed following sciatic nerve injury, particularly with regard to the cellular immune response at the nerve injury site.

  20. Ex vivo peripheral nerve detection of rats by spontaneous Raman spectroscopy

    PubMed Central

    Minamikawa, Takeo; Harada, Yoshinori; Takamatsu, Tetsuro

    2015-01-01

    Nerve-sparing surgery is increasingly being applied to avoid functional deficits of the limbs and organs following surgery. Peripheral nerves that should be preserved are, however, sometimes misidentified due to similarity of shape and color to non-nerve tissues. To avoid misidentification of peripheral nerves, development of an in situ nerve detection method is desired. In this study, we report the label-free detection of ex vivo peripheral nerves of Wistar rats by using Raman spectroscopy. We obtained Raman spectra of peripheral nerves (myelinated and unmyelinated nerves) and their adjacent tissues of Wistar rats without any treatment such as fixation and/or staining. For the identification of tissue species and further analysis of spectral features, we proposed a principal component regression-based discriminant analysis with representative Raman spectra of peripheral nerves and their adjacent tissues. Our prediction model selectively detected myelinated nerves and unmyelinated nerves of Wistar rats with respective sensitivities of 95.5% and 88.3% and specificities of 99.4% and 93.5%. Furthermore, important spectral features for the identification of tissue species were revealed by detailed analysis of principal components of representative Raman spectra of tissues. Our proposed approach may provide a unique and powerful tool for peripheral nerve detection for nerve-sparing surgery in the future. PMID:26602842

  1. Recording sympathetic nerve activity chronically in rats: surgery techniques, assessment of nerve activity, and quantification

    PubMed Central

    Muntzel, Martin S.

    2013-01-01

    The sympathetic nervous system plays a pivotal role in homeostasis through its direct innervation and functional impact on a variety of end organs. In rats, a number of methods are available to assess sympathetic nervous system function. Traditionally, direct recording of sympathetic nerve activity (SNA) has been restricted to acute, anesthetized preparations or conscious animals within a few days after electrode implantation. However, these approaches provide short-term data in studies designed to investigate changes in SNA during chronic disease states. Over the last several years, chronic SNA recording has been pioneered in rabbits and more recently in rats. The purpose of this article is to provide insights and a “how to” guide for chronic SNA recordings in rats based on experiences from two independent laboratories. We will present common methodologies used to chronically record SNA, characteristics and methods to distinguish sympathetic bursts versus electrical artifacts (and provide corresponding audio clips when available), and provide suggestions for analysis and presentation of data. In many instances, these same guidelines are applicable to acute SNA recordings. Using the surgical approaches described herein, both laboratories have been able to chronically record SNA in >50% of rats for a duration >3 wk. The ability to record SNA over the time course of several weeks will, undoubtedly, greatly impact the field of autonomic and cardiovascular physiology. PMID:24014674

  2. Far-Infrared Therapy Promotes Nerve Repair following End-to-End Neurorrhaphy in Rat Models of Sciatic Nerve Injury

    PubMed Central

    Chen, Tai-Yuan; Yang, Yi-Chin; Sha, Ya-Na; Chou, Jiun-Rou

    2015-01-01

    This study employed a rat model of sciatic nerve injury to investigate the effects of postoperative low-power far-infrared (FIR) radiation therapy on nerve repair following end-to-end neurorrhaphy. The rat models were divided into the following 3 groups: (1) nerve injury without FIR biostimulation (NI/sham group); (2) nerve injury with FIR biostimulation (NI/FIR group); and (3) noninjured controls (normal group). Walking-track analysis results showed that the NI/FIR group exhibited significantly higher sciatic functional indices at 8 weeks after surgery (P < 0.05) compared with the NI/sham group. The decreased expression of CD4 and CD8 in the NI/FIR group indicated that FIR irradiation modulated the inflammatory process during recovery. Compared with the NI/sham group, the NI/FIR group exhibited a significant reduction in muscle atrophy (P < 0.05). Furthermore, histomorphometric assessment indicated that the nerves regenerated more rapidly in the NI/FIR group than in the NI/sham group; furthermore, the NI/FIR group regenerated neural tissue over a larger area, as well as nerve fibers of greater diameter and with thicker myelin sheaths. Functional recovery, inflammatory response, muscular reinnervation, and histomorphometric assessment all indicated that FIR radiation therapy can accelerate nerve repair following end-to-end neurorrhaphy of the sciatic nerve. PMID:25722734

  3. L-carnitine alleviates sciatic nerve crush injury in rats: functional and electron microscopy assessments

    PubMed Central

    Avsar, Ümmü Zeynep; Avsar, Umit; Aydin, Ali; Yayla, Muhammed; Ozturkkaragoz, Berna; Un, Harun; Saritemur, Murat; Mercantepe, Tolga

    2014-01-01

    Several studies have demonstrated that L-carnitine exhibits neuroprotective effects on injured sciatic nerve of rats with diabetes mellitus. It is hypothesized that L-carnitine exhibits neuroprotective effects on injured sciatic nerve of rats. Rat sciatic nerve was crush injured by a forceps and exhibited degenerative changes. After intragastric administration of 50 and 100 mg/kg L-carnitine for 30 days, axon area, myelin sheath area, axon diameter, myelin sheath diameter, and numerical density of the myelinated axons of injured sciatic nerve were similar to normal, and the function of injured sciatic nerve also improved significantly. These findings suggest that L-carnitine exhibits neuroprotective effects on sciatic nerve crush injury in rats. PMID:25206754

  4. Effect of a high-intensity static magnetic field on sciatic nerve regeneration in the rat

    SciTech Connect

    Cordeiro, P.G.; Seckel, B.R.; Miller, C.D.; Gross, P.T.; Wise, R.E.

    1989-02-01

    The effect of a high-intensity static magnetic field on peripheral nerve regeneration is evaluated in rat sciatic nerve. Forty-four rats underwent sciatic nerve repair using polyethylene nerve guides. Postoperatively, the animals were exposed to a 1-tesla magnetic field for 12 hours per day for 4 weeks with appropriate controls. Our results demonstrate that a 1-tesla static magnetic field has no statistically significant effect on nerve regeneration as determined by myelinated axon counts and electrophysiologic studies. Also, the specific orientation of the sciatic nerve with respect to the magnetic field has no influence on axonal growth or nerve conduction. Periods of restraint of 12 hours per day for 4 weeks significantly inhibit weight gain but have no effect on peripheral nerve regeneration.

  5. An attenuated immune response by Schwann cells and macrophages inhibits nerve regeneration in aged rats.

    PubMed

    Scheib, Jami L; Höke, Ahmet

    2016-09-01

    Although peripheral nerves are capable of regeneration, advanced age decreases the potential for functional recovery after injury. The cellular mechanisms for this are not currently understood. Here, we performed sciatic nerve grafting with young (2 months old) and aged (18 months old) Brown-Norway male rats, in which 1 cm nerve grafts from young or aged rats were sutured into nerves of young or aged rats. Axons were allowed to regenerate until the nerve grafts and distal nerves were harvested at 1, 3, and 7 days and 2 and 6 weeks. At 6 weeks, our data suggested that young nerve grafts supported regeneration better than aged nerve grafts. In addition, myelin debris clearance was inhibited in young nerves when grafted into aged rats, but clearance was faster when aged nerves were grafted into young rats. Further analysis revealed that aged macrophages have delayed migration into injured nerve, and macrophages and Schwann cells from aged rats were less phagocytic for myelin debris in vitro. To understand these impairments, expression levels of pro- and anti-inflammatory cytokines were analyzed at 1 day after injury. Based on these levels, there was not a clear polarization to either an M1 or M2 phenotype; however, expression levels of IL-6, IL-10, CCL2 (MCP1), and Arg-1 were decreased in aged nerves. Taken together, both macrophages and Schwann cells had attenuated responses to nerve injury in aged rats, leading to inefficient clearance of debris and impaired axonal regeneration. PMID:27459920

  6. Re-Innervation of the Bladder through End-to-Side Neurorrhaphy of Autonomic Nerve and Somatic Nerve in Rats

    PubMed Central

    Gao, Wan-sheng; Dong, Chuan-jiang; Li, Shu-qiang; Kunwar, Kiran Jang

    2012-01-01

    Abstract End-to-side neurorrhaphy is widely used in the peripheral nervous system for nerve repair; however, the application of this technique has been limited to somatic nerves. The feasibility of nerve regeneration through end-to-side neurorrhaphy between autonomic and somatic nerves with different characteristics in the peripheral nervous system is still undetermined. In this study, rats were divided into three groups for different treatments (n=10 per group). In the end-to-side neurorrhaphy group, left L6 and S1 were transected in the dura, and the distal stump of L6 ventral root was sutured to the lateral face of L4 ventral root through end-to-side coaptation. In the no repair group, the rats did not undergo neurorrhaphy. In the control group, the left L6 dorsal root and S1 roots were transected, respectively, but the L6 ventral root was kept intact. After 16 weeks, the origin and mechanism of nerve regeneration was evaluated by retrograde double labeling technique as well as histological examination and intravesical pressure measurement. Retrograde double labeling indicated that the reconstructed reflex pathway was successfully established and the primary regeneration mechanism involved axon collateral sprouting. Morphological examination and intravesical pressure measurement indicated prominent nerve regeneration and successful re-innervation of the bladder in the neurorrhaphy group, compared with the “no repair” group (p<0.05). No significant changes were observed in the histology of the donor nerve and the bilateral extensor digitorum longus muscles in the neurorrhaphy group. Nerve regeneration may be achievable for nerve repair through end-to-side neurorrhaphy between autonomic and somatic nerves without apparent impairment of donor somatic nerve. PMID:22332710

  7. Morphological specialisations of rat cranial nerve transitional zones.

    PubMed

    Fraher, J P; O'Leary, D

    1994-02-01

    Near their CNS-PNS transitional zones (TZs), many rat cranial nerve rootlets are subdivided to a marked degree by a reticulum of fine cytoplasmic processes. Some of the resulting compartments contain only a single myelinated fibre or a bundle of collagen fibrils. The compartments are aligned with the astrocytic tunnels in which the fibres lie as they traverse the CNS-PNS transitional zone. This marked subdivision may help to insulate individual fibres from one another, preventing functional interaction between them. Rootlet sheath cells commonly are closely apposed to, or interdigitate with, astrocyte processes of the TZ. These features may help to strengthen the delicate TZ. The TZ of the trochlear nerve includes a long, generally avascular, central tissue projection (CTP) into the proximal part of the nerve. This is connected to the brainstem and cerebellum by astrocytic bridges. In contrast to the CTP, which is generally avascular, these contain abundant blood vessels which may facilitate metabolic exchange in the trochlear TZ. PMID:8157484

  8. Dexamethasone enhanced functional recovery after sciatic nerve crush injury in rats.

    PubMed

    Feng, Xinhong; Yuan, Wei

    2015-01-01

    Dexamethasone is currently used for the treatment of peripheral nerve injury, but its mechanisms of action are not completely understood. Inflammation/immune response at the site of nerve lesion is known to be an essential trigger of the pathological changes that have a critical impact on nerve repair and regeneration. In this study, we observed the effects of various doses of dexamethasone on the functional recovery after sciatic nerve crush injury in a rat model. Motor functional recovery was monitored by walking track analysis and gastrocnemius muscle mass ratio. The myelinated axon number was counted by morphometric analysis. Rats administered dexamethasone by local intramuscular injection had a higher nerve function index value, increased gastrocnemius muscle mass ratio, reduced Wallerian degeneration severity, and enhanced regenerated myelinated nerve fibers. Immunohistochemical analysis was performed for CD3 expression, which is a marker for T-cell activation, and infiltration in the sciatic nerve. Dexamethasone-injected rats had fewer CD3-positive cells compared to controls. Furthermore, we found increased expression of GAP-43, which is a factor associated with development and plasticity of the nervous system, in rat nerves receiving dexamethasone. These results provide strong evidence that dexamethasone enhances sciatic nerve regeneration and function recovery in a rat model of sciatic nerve injury through immunosuppressive and potential neurotrophic effects. PMID:25839037

  9. Dexamethasone Enhanced Functional Recovery after Sciatic Nerve Crush Injury in Rats

    PubMed Central

    Feng, Xinhong; Yuan, Wei

    2015-01-01

    Dexamethasone is currently used for the treatment of peripheral nerve injury, but its mechanisms of action are not completely understood. Inflammation/immune response at the site of nerve lesion is known to be an essential trigger of the pathological changes that have a critical impact on nerve repair and regeneration. In this study, we observed the effects of various doses of dexamethasone on the functional recovery after sciatic nerve crush injury in a rat model. Motor functional recovery was monitored by walking track analysis and gastrocnemius muscle mass ratio. The myelinated axon number was counted by morphometric analysis. Rats administered dexamethasone by local intramuscular injection had a higher nerve function index value, increased gastrocnemius muscle mass ratio, reduced Wallerian degeneration severity, and enhanced regenerated myelinated nerve fibers. Immunohistochemical analysis was performed for CD3 expression, which is a marker for T-cell activation, and infiltration in the sciatic nerve. Dexamethasone-injected rats had fewer CD3-positive cells compared to controls. Furthermore, we found increased expression of GAP-43, which is a factor associated with development and plasticity of the nervous system, in rat nerves receiving dexamethasone. These results provide strong evidence that dexamethasone enhances sciatic nerve regeneration and function recovery in a rat model of sciatic nerve injury through immunosuppressive and potential neurotrophic effects. PMID:25839037

  10. The effects of electroacupuncture on peripheral nerve regeneration in rats.

    PubMed

    Inoue, Motohiro; Hojo, Tatsuya; Yano, Tadashi; Katsumi, Yasukazu

    2003-06-01

    This study was designed to examine the effects of electroacupuncture with direct current (DC) on peripheral nerve regeneration. The left sciatic nerve of 55 7-month-old rats was crushed at the thigh. They were ramdomly allocated to four groups: distal cathode DC group (n = 15), distal anode DC group (n = 14), sham operated group (n = 13), and control group (n = 13). In the distal cathode DC group, a cathode electrode was connected to an insulated acupuncture needle inserted at 1 cm distal to the injured site, while an anode electrode was connected to a needle inserted at 1 cm proximal to the lesion. In the distal anode DC group, the anode and the cathode electrode were connected to the needle at 1 cm distal and proximal to the lesion respectively. In the sham operated group, no electrical stimulation was given to the insulated needle inserted at the same site, and in the control group, no treatment was given. Regeneration of the sciatic nerve was evaluated by the number of evoked EMGs recorded at 12 sites in the plantar region, by their latency, and by the weight ratio of the tibialis anterior at four weeks after the crush injury. Regeneration of the peripheral nerve was faster and more accelerated in the distal cathode DC group than in the other groups, while in the distal anode DC group the regeneration was delayed. This result suggested electroacupuncture with cathode distal orientation might be a useful treatment having the advantage of enabling deeper insertion with minimal tissue damage. PMID:12924841

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

    SciTech Connect

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

    2013-10-18

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

  12. Peripheral Nerve Repair in Rats Using Composite Hydrogel-Filled Aligned Nanofiber Conduits with Incorporated Nerve Growth Factor

    PubMed Central

    Jin, Jenny; Limburg, Sonja; Joshi, Sunil K.; Landman, Rebeccah; Park, Michelle; Zhang, Qia; Kim, Hubert T.

    2013-01-01

    Repair of peripheral nerve defects with current synthetic, tubular nerve conduits generally shows inferior recovery when compared with using nerve autografts, the current gold standard. We tested the ability of composite collagen and hyaluronan hydrogels, with and without the nerve growth factor (NGF), to stimulate neurite extension on a promising aligned, nanofiber poly-L-lactide-co-caprolactone (PLCL) scaffold. In vitro, the hydrogels significantly increased neurite extension from dorsal root ganglia explants. Consistent with these results, the addition of hydrogels as luminal fillers within aligned, nanofiber tubular PLCL conduits led to improved sensory function compared to autograft repair in a critical-size defect in the sciatic nerve in a rat model. Sensory recovery was assessed 3 and 12 weeks after repair using a withdrawal assay from thermal stimulation. The addition of hydrogel did not enhance recovery of motor function in the rat model. The NGF led to dose-dependent improvements in neurite out-growth in vitro, but did not have a significant effect in vivo. In summary, composite collagen/hyaluronan hydrogels enhanced sensory neurite outgrowth in vitro and sensory recovery in vivo. The use of such hydrogels as luminal fillers for tubular nerve conduits may therefore be useful in assisting restoration of protective sensation following peripheral nerve injury. PMID:23659607

  13. Low-intensity pulsed ultrasound treatment improved the rate of autograft peripheral nerve regeneration in rat.

    PubMed

    Jiang, Wenli; Wang, Yuexiang; Tang, Jie; Peng, Jiang; Wang, Yu; Guo, Quanyi; Guo, Zhiyuan; Li, Pan; Xiao, Bo; Zhang, Jinxing

    2016-01-01

    Low intensity pulsed ultrasound (LIPUS) has been widely used in clinic for the treatment of repairing pseudarthrosis, bone fractures and of healing in various soft tissues. Some reports indicated that LIPUS accelerated peripheral nerve regeneration including Schwann cells (SCs) and injured nerves. But little is known about its appropriate intensities on autograft nerves. This study was to investigate which intensity of LIPUS improved the regeneration of gold standard postsurgical nerves in experimental rat model. Sprague-Dawley rats were made into 10 mm right side sciatic nerve reversed autologous nerve transplantation and randomly treated with 250 mW/cm(2), 500 mW/cm(2) or 750 mW/cm(2) LIPUS for 2-12 weeks after operation. Functional and pathological results showed that LIPUS of 250 mW/cm(2) significantly induced faster rate of axonal regeneration. This suggested that autograft nerve regeneration was improved. PMID:27102358

  14. Low-intensity pulsed ultrasound treatment improved the rate of autograft peripheral nerve regeneration in rat

    PubMed Central

    Jiang, Wenli; Wang, Yuexiang; Tang, Jie; Peng, Jiang; Wang, Yu; Guo, Quanyi; Guo, Zhiyuan; Li, Pan; Xiao, Bo; Zhang, Jinxing

    2016-01-01

    Low intensity pulsed ultrasound (LIPUS) has been widely used in clinic for the treatment of repairing pseudarthrosis, bone fractures and of healing in various soft tissues. Some reports indicated that LIPUS accelerated peripheral nerve regeneration including Schwann cells (SCs) and injured nerves. But little is known about its appropriate intensities on autograft nerves. This study was to investigate which intensity of LIPUS improved the regeneration of gold standard postsurgical nerves in experimental rat model. Sprague-Dawley rats were made into 10 mm right side sciatic nerve reversed autologous nerve transplantation and randomly treated with 250 mW/cm2, 500 mW/cm2 or 750 mW/cm2 LIPUS for 2–12 weeks after operation. Functional and pathological results showed that LIPUS of 250 mW/cm2 significantly induced faster rate of axonal regeneration. This suggested that autograft nerve regeneration was improved. PMID:27102358

  15. Vagus nerve stimulation delivered during motor rehabilitation improves recovery in a rat model of stroke.

    PubMed

    Khodaparast, Navid; Hays, Seth A; Sloan, Andrew M; Fayyaz, Tabbassum; Hulsey, Daniel R; Rennaker, Robert L; Kilgard, Michael P

    2014-09-01

    Neural plasticity is widely believed to support functional recovery following brain damage. Vagus nerve stimulation paired with different forelimb movements causes long-lasting map plasticity in rat primary motor cortex that is specific to the paired movement. We tested the hypothesis that repeatedly pairing vagus nerve stimulation with upper forelimb movements would improve recovery of motor function in a rat model of stroke. Rats were separated into 3 groups: vagus nerve stimulation during rehabilitation (rehab), vagus nerve stimulation after rehab, and rehab alone. Animals underwent 4 training stages: shaping (motor skill learning), prelesion training, postlesion training, and therapeutic training. Rats were given a unilateral ischemic lesion within motor cortex and implanted with a left vagus nerve cuff. Animals were allowed 1 week of recovery before postlesion baseline training. During the therapeutic training stage, rats received vagus nerve stimulation paired with each successful trial. All 17 trained rats demonstrated significant contralateral forelimb impairment when performing a bradykinesia assessment task. Forelimb function was recovered completely to prelesion levels when vagus nerve stimulation was delivered during rehab training. Alternatively, intensive rehab training alone (without stimulation) failed to restore function to prelesion levels. Delivering the same amount of stimulation after rehab training did not yield improvements compared with rehab alone. These results demonstrate that vagus nerve stimulation repeatedly paired with successful forelimb movements can improve recovery after motor cortex ischemia and may be a viable option for stroke rehabilitation. PMID:24553102

  16. Rat Whisker Movement after Facial Nerve Lesion: Evidence for Autonomic Contraction of Skeletal Muscle

    PubMed Central

    Heaton, James T.; Sheu, Shu-Hsien; Hohman, Marc H.; Knox, Christopher J.; Weinberg, Julie S.; Kleiss, Ingrid J.; Hadlock, Tessa A.

    2014-01-01

    Vibrissal whisking is often employed to track facial nerve regeneration in rats; however, we have observed similar degrees of whisking recovery after facial nerve transection with or without repair. We hypothesized that the source of non-facial nerve-mediated whisker movement after chronic denervation was from autonomic, cholinergic axons traveling within the infraorbital branch of the trigeminal nerve (ION). Rats underwent unilateral facial nerve transection with repair (N=7) or resection without repair (N=11). Post-operative whisking amplitude was measured weekly across 10 weeks, and during intraoperative stimulation of the ION and facial nerves at ≥18 weeks. Whisking was also measured after subsequent ION transection (N=6) or pharmacologic blocking of the autonomic ganglia using hexamethonium (N=3), and after snout cooling intended to elicit a vasodilation reflex (N=3). Whisking recovered more quickly and with greater amplitude in rats that underwent facial nerve repair compared to resection (P<0.05), but individual rats overlapped in whisking amplitude across both groups. In the resected rats, non-facial-nerve mediated whisking was elicited by electrical stimulation of the ION, temporarily diminished following hexamethonium injection, abolished by transection of the ION, and rapidly and significantly (P<0.05) increased by snout cooling. Moreover, fibrillation-related whisker movements decreased in all rats during the initial recovery period (indicative of reinnervation), but re-appeared in the resected rats after undergoing ION transection (indicative of motor denervation). Cholinergic, parasympathetic axons traveling within the ION innervate whisker pad vasculature, and immunohistochemistry for vasoactive intestinal peptide revealed these axons branching extensively over whisker pad muscles and contacting neuromuscular junctions after facial nerve resection. This study provides the first behavioral and anatomical evidence of spontaneous autonomic innervation

  17. Epineurial Window Is More Efficient in Attracting Axons than Simple Coaptation in a Sutureless (Cyanoacrylate-Bound) Model of End-to-Side Nerve Repair in the Rat Upper Limb: Functional and Morphometric Evidences and Review of the Literature

    PubMed Central

    Papalia, Igor; Magaudda, Ludovico; Righi, Maria; Ronchi, Giulia; Viano, Nicoletta; Geuna, Stefano; Colonna, Michele Rosario

    2016-01-01

    End-to-side nerve coaptation brings regenerating axons from the donor to the recipient nerve. Several techniques have been used to perform coaptation: microsurgical sutures with and without opening a window into the epi(peri)neurial connective tissue; among these, window techniques have been proven more effective in inducing axonal regeneration. The authors developed a sutureless model of end-to-side coaptation in the rat upper limb. In 19 adult Wistar rats, the median and the ulnar nerves of the left arm were approached from the axillary region, the median nerve transected and the proximal stump sutured to the pectoral muscle to prevent regeneration. Animals were then randomly divided in two experimental groups (7 animals each, 5 animals acting as control): Group 1: the distal stump of the transected median nerve was fixed to the ulnar nerve by applying cyanoacrylate solution; Group 2: a small epineurial window was opened into the epineurium of the ulnar nerve, caring to avoid damage to the nerve fibres; the distal stump of the transected median nerve was then fixed to the ulnar nerve by applying cyanoacrylate solution. The grasping test for functional evaluation was repeated every 10–11 weeks starting from week-15, up to the sacrifice (week 36). At week 36, the animals were sacrificed and the regenerated nerves harvested and processed for morphological investigations (high-resolution light microscopy as well as stereological and morphometrical analysis). This study shows that a) cyanoacrylate in end-to-side coaptation produces scarless axon regeneration without toxic effects; b) axonal regeneration and myelination occur even without opening an epineurial window, but c) the window is related to a larger number of regenerating fibres, especially myelinated and mature, and better functional outcomes. PMID:26872263

  18. Epineurial Window Is More Efficient in Attracting Axons than Simple Coaptation in a Sutureless (Cyanoacrylate-Bound) Model of End-to-Side Nerve Repair in the Rat Upper Limb: Functional and Morphometric Evidences and Review of the Literature.

    PubMed

    Papalia, Igor; Magaudda, Ludovico; Righi, Maria; Ronchi, Giulia; Viano, Nicoletta; Geuna, Stefano; Colonna, Michele Rosario

    2016-01-01

    End-to-side nerve coaptation brings regenerating axons from the donor to the recipient nerve. Several techniques have been used to perform coaptation: microsurgical sutures with and without opening a window into the epi(peri)neurial connective tissue; among these, window techniques have been proven more effective in inducing axonal regeneration. The authors developed a sutureless model of end-to-side coaptation in the rat upper limb. In 19 adult Wistar rats, the median and the ulnar nerves of the left arm were approached from the axillary region, the median nerve transected and the proximal stump sutured to the pectoral muscle to prevent regeneration. Animals were then randomly divided in two experimental groups (7 animals each, 5 animals acting as control): Group 1: the distal stump of the transected median nerve was fixed to the ulnar nerve by applying cyanoacrylate solution; Group 2: a small epineurial window was opened into the epineurium of the ulnar nerve, caring to avoid damage to the nerve fibres; the distal stump of the transected median nerve was then fixed to the ulnar nerve by applying cyanoacrylate solution. The grasping test for functional evaluation was repeated every 10-11 weeks starting from week-15, up to the sacrifice (week 36). At week 36, the animals were sacrificed and the regenerated nerves harvested and processed for morphological investigations (high-resolution light microscopy as well as stereological and morphometrical analysis). This study shows that a) cyanoacrylate in end-to-side coaptation produces scarless axon regeneration without toxic effects; b) axonal regeneration and myelination occur even without opening an epineurial window, but c) the window is related to a larger number of regenerating fibres, especially myelinated and mature, and better functional outcomes. PMID:26872263

  19. Transcriptome profiling of the rat retina after optic nerve transection

    PubMed Central

    Yasuda, Masayuki; Tanaka, Yuji; Omodaka, Kazuko; Nishiguchi, Koji M.; Nakamura, Orie; Tsuda, Satoru; Nakazawa, Toru

    2016-01-01

    Glaucoma is a group of eye diseases characterized by alterations in the contour of the optic nerve head (ONH), with corresponding visual field defects and progressive loss of retinal ganglion cells (RGCs). This progressive RGC death is considered to originate in axonal injury caused by compression of the axon bundles in the ONH. However, the molecular pathomechanisms of axonal injury-induced RGC death are not yet well understood. Here, we used RNA sequencing (RNA-seq) to examine transcriptome changes in rat retinas 2 days after optic nerve transection (ONT), and then used computational techniques to predict the resulting alterations in the transcriptional regulatory network. RNA-seq revealed 267 differentially expressed genes after ONT, 218 of which were annotated and 49 unannotated. We also identified differentially expressed transcripts, including potentially novel isoforms. An in silico pathway analysis predicted that CREB1 was the most significant upstream regulator. Thus, this study identified genes and pathways that may be involved in the pathomechanisms of axonal injury. We believe that our data should serve as a valuable resource to understand the molecular processes that define axonal injury-driven RGC death and to discover novel therapeutic targets for glaucoma. PMID:27353354

  20. Toxicity and median effective doses of oxime therapies against percutaneous organophosphorus pesticide and nerve agent challenges in the Hartley guinea pig.

    PubMed

    Snider, Thomas H; Babin, Michael C; Jett, David A; Platoff, Gennady E; Yeung, David T

    2016-01-01

    Anticholinesterases, such as organophosphorus pesticides and warfare nerve agents, present a significant health threat. Onset of symptoms after exposure can be rapid, requiring quick-acting, efficacious therapy to mitigate the effects. The goal of the current study was to identify the safest antidote with the highest therapeutic index (TI = oxime 24-hr LD50/oxime ED50) from a panel of four oximes deemed most efficacious in a previous study. The oximes tested were pralidoxime chloride (2-PAM Cl), MMB4 DMS, HLö-7 DMS, and obidoxime Cl2. The 24-hr median lethal dose (LD50) for the four by intramuscular (IM) injection and the median effective dose (ED50) were determined. In the ED50 study, male guinea pigs clipped of hair received 2x LD50 topical challenges of undiluted Russian VX (VR), VX, or phorate oxon (PHO) and, at the onset of cholinergic signs, IM therapy of atropine (0.4 mg/kg) and varying levels of oxime. Survival was assessed at 3 hr after onset clinical signs. The 3-hr 90th percentile dose (ED90) for each oxime was compared to the guinea pig pre-hospital human-equivalent dose of 2-PAM Cl, 149 µmol/kg. The TI was calculated for each OP/oxime combination. Against VR, MMB4 DMS had a higher TI than HLö-7 DMS, whereas 2-PAM Cl and obidoxime Cl2 were ineffective. Against VX, MMB4 DMS > HLö-7 DMS > 2-PAM Cl > obidoxime Cl2. Against PHO, all performed better than 2-PAM Cl. MMB4 DMS was the most effective oxime as it was the only oxime with ED90 < 149 µmol/kg against all three topical OPs tested. PMID:27432237

  1. Intraneural perineurioma of unilateral radial and median nerves manifesting with long-standing focal amyotrophy in a 14-year-old-boy.

    PubMed

    Nagappa, Madhu; Chickabasaviah, Yasha T; Bharath, Rose D; Bindu, Parayil S; Sinha, Sanjib; Taly, Arun B

    2013-12-01

    Intraneural perineuriomas are rare tumors of the peripheral nerves with unique immunohistochemical findings. In this report, we highlight the clinical and imaging findings of an adolescent male with histologically proven intraneural perineurioma involving multiple nerves. The salient features included a clinically progressive course, imaging evidence of involvement of long segments of multiple nerves, enlargement of individual fascicles within the affected nerves, and intense contrast enhancement of the enlarged fascicles. The identification of enlarged fascicles with intense contrast enhancement within the affected and distended nerve segments may aid in distinguishing intraneural perineurioma from other tumors affecting the peripheral nerves. PMID:24263031

  2. Photostimulation of sensory neurons of the rat vagus nerve

    NASA Astrophysics Data System (ADS)

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

    2008-02-01

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

  3. Streptozotocin induced diabetes as a model of phrenic nerve neuropathy in rats.

    PubMed

    Rodrigues Filho, Omar Andrade; Fazan, Valéria Paula Sassoli

    2006-03-15

    Phrenic neuropathies are increasingly recognized in peripheral neuropathies but reports on experimental models of the phrenic nerves diabetic neuropathy are scanty. In the present study, we investigated the phrenic nerve neuropathy, due to experimental diabetes induced by streptozotocin (STZ) and the evolution of this neuropathy in diabetic rats treated with insulin. Proximal and distal segments of the left and right phrenic nerves were morphologically and morphometrically evaluated, from rats rendered diabetic for 12 weeks, by injection of STZ. Control rats received vehicle. Treated rats received a single subcutaneous injection of insulin on a daily basis. The nerves were prepared for light microcopy study by means of conventional techniques. Morphometry was carried out with the aid of computer software. The phrenic nerves of diabetic rats showed smaller myelinated axon diameters compared to controls. The g ratio was significantly smaller for myelinated fibers from diabetic rats compared to controls. Insulin treatment prevented these alterations. Histograms of size distribution for myelinated fibers and axons from control rats were bimodal. For diabetic animals, the myelinated fiber histogram was bimodal while the axon distribution turned to be unimodal. Insulin treatment also prevented these alterations. Our results confirm the phrenic nerve neuropathy in this experimental model of diabetes and suggest that conventional insulin treatment was able to prevent and/or correct the myelinated axon commitment by diabetes. PMID:16125783

  4. Nerve growth factor facilitates redistribution of adrenergic and non-adrenergic non-cholinergic perivascular nerves injured by phenol in rat mesenteric resistance arteries.

    PubMed

    Yokomizo, Ayako; Takatori, Shingo; Hashikawa-Hobara, Narumi; Goda, Mitsuhiro; Kawasaki, Hiromu

    2016-01-01

    We previously reported that nerve growth factor (NGF) facilitated perivascular sympathetic neuropeptide Y (NPY)- and calcitonin gene-related peptide (CGRP)-containing nerves injured by the topical application of phenol in the rat mesenteric artery. We also demonstrated that mesenteric arterial nerves were distributed into tyrosine hydroxylase (TH)-, substance P (SP)-, and neuronal nitric oxide synthase (nNOS)-containing nerves, which had axo-axonal interactions. In the present study, we examined the effects of NGF on phenol-injured perivascular nerves, including TH-, NPY-, nNOS-, CGRP-, and SP-containing nerves, in rat mesenteric arteries in more detail. Wistar rats underwent the in vivo topical application of 10% phenol to the superior mesenteric artery, proximal to the abdominal aorta, under pentobarbital-Na anesthesia. The distribution of perivascular nerves in the mesenteric arteries of the 2nd to 3rd-order branches isolated from 8-week-old Wistar rats was investigated immunohistochemically using antibodies against TH-, NPY-, nNOS-, CGRP-, and SP-containing nerves. The topical phenol treatment markedly reduced the density of all nerves in these arteries. The administration of NGF at a dose of 20µg/kg/day with an osmotic pump for 7 days significantly increased the density of all perivascular nerves over that of sham control levels. These results suggest that NGF facilitates the reinnervation of all perivascular nerves injured by phenol in small resistance arteries. PMID:26671004

  5. Identification of Changes in Gene expression of rats after Sensory and Motor Nerves Injury

    PubMed Central

    Wang, Yu; Guo, Zhi-Yuan; Sun, Xun; Lu, Shi-bi; Xu, Wen-Jing; Zhao, Qing; Peng, Jiang

    2016-01-01

    Wallerian degeneration is a sequence of events in the distal stump of axotomized nerves. Despite large numbers of researches concentrating on WD, the biological mechanism still remains unclear. Hence we constructed a rat model with both motor and sensory nerves injury and then conducted a RNA-seq analysis. Here the rats were divided into the 4 following groups: normal motor nerves (NMN), injured motor nerves (IMN), normal sensory nerves (NSN) and injured sensory nerves (ISN). The transcriptomes of rats were sequenced by the Illumina HiSeq. The differentially expressed genes (DEGs) of 4 combinations including NMN vs. IMN, NSN vs. ISN, NMN vs. NSN and IMN vs. ISN were identified respectively. For the above 4 combinations, we identified 1666, 1514, 95 and 17 DEGs. We found that NMN vs. IMN shared the most common genes with NSN vs. ISN indicating common mechanisms between motor nerves injury and sensory nerves injury. At last, we performed an enrichment analysis and observed that the DEGs of NMN vs IMN and NSN vs. ISN were significantly associated with binding and activity, immune response, biosynthesis, metabolism and development. We hope our study may shed light on the molecular mechanisms of nerves degeneration and regeneration during WD. PMID:27253193

  6. Improved peripheral nerve regeneration in streptozotocin-induced diabetic rats by oral lumbrokinase.

    PubMed

    Lee, Han-Chung; Hsu, Yuan-Man; Tsai, Chin-Chuan; Ke, Cherng-Jyh; Yao, Chun-Hsu; Chen, Yueh-Sheng

    2015-01-01

    We assessed the therapeutic effects of lumbrokinase, a group of enzymes extracted from the earthworm, on peripheral-nerve regeneration using well-defined sciatic nerve lesion paradigms in diabetic rats induced by the injection of streptozotocin (STZ). We found that lumbrokinase therapy could improve the rats' circulatory blood flow and promote the regeneration of axons in a silicone rubber conduit after nerve transection. Lumbrokinase treatment could also improve the neuromuscular functions with better nerve conductive performances. Immunohistochemical staining showed that lumbrokinase could dramatically promote calcitonin gene-related peptide (CGRP) expression in the lamina I-II regions in the dorsal horn ipsilateral to the injury and cause a marked increase in the number of macrophages recruited within the distal nerve stumps. In addition, the lumbrokinase could stimulate the secretion of interleukin-1 (IL-1), nerve growth factor (NGF), platelet-derived growth factor (PDGF), and transforming growth factor-β (TGF-β) in dissected diabetic sciatic nerve segments. In conclusion, the administration of lumbrokinase after nerve repair surgery in diabetic rats was found to have remarkable effects on promoting peripheral nerve regeneration and functional recovery. PMID:25787300

  7. Identification of Changes in Gene expression of rats after Sensory and Motor Nerves Injury.

    PubMed

    Wang, Yu; Guo, Zhi-Yuan; Sun, Xun; Lu, Shi-Bi; Xu, Wen-Jing; Zhao, Qing; Peng, Jiang

    2016-01-01

    Wallerian degeneration is a sequence of events in the distal stump of axotomized nerves. Despite large numbers of researches concentrating on WD, the biological mechanism still remains unclear. Hence we constructed a rat model with both motor and sensory nerves injury and then conducted a RNA-seq analysis. Here the rats were divided into the 4 following groups: normal motor nerves (NMN), injured motor nerves (IMN), normal sensory nerves (NSN) and injured sensory nerves (ISN). The transcriptomes of rats were sequenced by the Illumina HiSeq. The differentially expressed genes (DEGs) of 4 combinations including NMN vs. IMN, NSN vs. ISN, NMN vs. NSN and IMN vs. ISN were identified respectively. For the above 4 combinations, we identified 1666, 1514, 95 and 17 DEGs. We found that NMN vs. IMN shared the most common genes with NSN vs. ISN indicating common mechanisms between motor nerves injury and sensory nerves injury. At last, we performed an enrichment analysis and observed that the DEGs of NMN vs IMN and NSN vs. ISN were significantly associated with binding and activity, immune response, biosynthesis, metabolism and development. We hope our study may shed light on the molecular mechanisms of nerves degeneration and regeneration during WD. PMID:27253193

  8. Hydrogen-rich saline promotes motor functional recovery following peripheral nerve autografting in rats

    PubMed Central

    ZHANG, YONG-GUANG; SHENG, QING-SONG; WANG, ZHI-JUN; LV, LI; ZHAO, WEI; CHEN, JIAN-MEI; XU, HAO

    2015-01-01

    Despite the application of nerve grafts and considerable microsurgical innovations, the functional recovery across a long peripheral nerve gap is generally partial and unsatisfactory. Thus, additional strategies are required to improve nerve regeneration across long nerve gaps. Hydrogen possesses antioxidant and anti-apoptotic properties, which could be neuroprotective in the treatment of peripheral nerve injury; however, such a possibility has not been experimentally tested in vivo. The aim of the present study was to investigate the effectiveness of hydrogen-rich saline in promoting nerve regeneration after 10-mm sciatic nerve autografting in rats. The rats were randomly divided into two groups and intraperitoneally administered a daily regimen of 5 ml/kg hydrogen-rich or normal saline. Axonal regeneration and functional recovery were assessed through a combination of behavioral analyses, electrophysiological evaluations, Fluoro-Gold™ retrograde tracings and histomorphological observations. The data showed that rats receiving hydrogen-rich saline achieved better axonal regeneration and functional recovery than those receiving normal saline. These findings indicated that hydrogen-rich saline promotes nerve regeneration across long gaps, suggesting that hydrogen-rich saline could be used as a neuroprotective agent for peripheral nerve injury therapy. PMID:26622383

  9. Rat sciatic nerve reconstruction across a 30 mm defect bridged by an oriented porous PHBV tube with Schwann cell as artificial nerve graft.

    PubMed

    Karimi, Mina; Biazar, Esmaeil; Keshel, Saeed Heidari; Ronaghi, Abdolaziz; Doostmohamadpour, Jafar; Janfada, Alireza; Montazeri, Arash

    2014-01-01

    An oriented poly(3-hydroxybutyrate-co-3-hydroxyvalerate) nerve conduit has been used to evaluate its efficiency based on the promotion of peripheral nerve regeneration in rats. The oriented porous micropatterned artificial nerve conduit was designed onto the micropatterned silicon wafers, and then their surfaces were modified with oxygen plasma to increase cell adhesion. The designed conduits were investigated by cell culture analyses with Schwann cells (SCs). The conduits were implanted into a 30 mm gap in sciatic nerves of rats. Four months after surgery, the regenerated nerves were monitored and evaluated by macroscopic assessments and histology and behavioral analyses. Results of cellular analyses showed suitable properties of designed conduit for nerve regeneration. The results demonstrated that in the polymeric graft with SCs, the rat sciatic nerve trunk had been reconstructed with restoration of nerve continuity and formatted nerve fibers with myelination. Histological results demonstrated the presence of Schwann and glial cells in regenerated nerves. Functional recovery such as walking, swimming, and recovery of nociceptive function was illustrated for all the grafts especially conduits with SCs. This study proves the feasibility of the artificial nerve graft filled with SCs for peripheral nerve regeneration by bridging a longer defect in an animal model. PMID:24399063

  10. Rat Sciatic Nerve Reconstruction Across a 30 mm Defect Bridged by an Oriented Porous PHBV Tube With Schwann Cell as Artificial Nerve Graft

    PubMed Central

    2014-01-01

    An oriented poly(3-hydroxybutyrate-co-3-hydroxyvalerate) nerve conduit has been used to evaluate its efficiency based on the promotion of peripheral nerve regeneration in rats. The oriented porous micropatterned artificial nerve conduit was designed onto the micropatterned silicon wafers, and then their surfaces were modified with oxygen plasma to increase cell adhesion. The designed conduits were investigated by cell culture analyses with Schwann cells (SCs). The conduits were implanted into a 30 mm gap in sciatic nerves of rats. Four months after surgery, the regenerated nerves were monitored and evaluated by macroscopic assessments and histology and behavioral analyses. Results of cellular analyses showed suitable properties of designed conduit for nerve regeneration. The results demonstrated that in the polymeric graft with SCs, the rat sciatic nerve trunk had been reconstructed with restoration of nerve continuity and formatted nerve fibers with myelination. Histological results demonstrated the presence of Schwann and glial cells in regenerated nerves. Functional recovery such as walking, swimming, and recovery of nociceptive function was illustrated for all the grafts especially conduits with SCs. This study proves the feasibility of the artificial nerve graft filled with SCs for peripheral nerve regeneration by bridging a longer defect in an animal model. PMID:24399063

  11. Biomechanical and functional variation in rat sciatic nerve following cuff electrode implantation

    PubMed Central

    2014-01-01

    Background Nerve cuff electrodes are commonly and successfully used for stimulating peripheral nerves. On the other hand, they occasionally induce functional and morphological changes following chronic implantation, for reasons not always clear. We hypothesize that restriction of nerve mobility due to cuff implantation may alter nerve conduction. Methods We quantified acute changes in nerve-muscle electrophysiology, using electromyography, and nerve kinematics in anesthetized Sprague Dawley rat sciatic nerves during controlled hindlimb joint movement. We compared electrophysiological and biomechanical response in uncuffed nerves and those secured within a cuff electrode using analysis of variance (ANOVA) and regression analysis. Results Tethering resulting from cuff implantation resulted in altered nerve strain and a complex biomechanical environment during joint movement. Coincident with biomechanical changes, electromyography revealed significantly increased variability in the response of conduction latency and amplitude in cuffed, but not free, nerves following joint movement. Conclusion Our findings emphasize the importance of the mechanical interface between peripheral nerves and their devices on neurophysiological performance. This work has implications for nerve device design, implantation, and prediction of long-term efficacy. PMID:24758405

  12. The Effects of Granulocyte-Colony Stimulating Factor on Regeneration in Nerve Crush Injuries in Rats.

    PubMed

    Song, Yi-Sun; Joe, Jun-Ho; Joo, Hyun-Woo; Park, In-Hwa; Shen, Guang-Yin; Kim, Ki-Jun; Lee, Yonggu; Shin, Jeong Hun; Kim, Hyuck; Kim, Kyung-Soo

    2016-07-01

    Granulocyte-colony stimulating factor (G-CSF) is widely known to have a neuroprotective effect, but its effects on function and morphology in mechanical nerve injury are not well understood. The aim of this study was to confirm the time course of the functional changes and morphological effects of G-CSF in a rat model of nerve crush injury. Twelve-eight rats were divided into three group: sham-operated control group, G-CSF-treated group, and saline treated group. 2 weeks after the nerve crush injury, G-CSF was injected for 5 days. After 4 weeks, functional tests such as motor nerve conduction velocity (MNCV), mechanical and cold allodynia tests, and morphological studies were performed. G-CSF-treated rats had significantly improved nerve function including MNCV and mechanical and cold allodynia. In addition, G-CSF-treated rats had significantly higher the density of myelinated fibers than saline-treated rats. In conclusion, we found that 100 μg/kg administration of G-CSF promoted long-term functional recovery in a rat model of nerve crush injury. PMID:26980007

  13. Specific neurotoxin lesions of median raphe serotonergic neurons disrupt maternal behavior in the lactating rat.

    PubMed

    Barofsky, A L; Taylor, J; Tizabi, Y; Kumar, R; Jones-Quartey, K

    1983-11-01

    Impairments in lactation after electrolytic lesions of the median raphe (MR) nucleus have been corrected by treatment with PRL. Specific serotonin neurotoxin lesions were used in the present study to determine whether decrements in litter growth after electrolytic lesions could be attributed to serotonergic neuron damage at the MR locus, and whether MR lesions (MRL) disrupted suckling-induced PRL release. Intracerebral microinjection of 5,7-dihydroxytryptamine (5,7-DHT) into the MR nucleus produced dose-related decrements in litter growth after either 4 micrograms (sham, 1.35 +/- 0.05; MRL, 1.04 +/- 0.05 g/pup X day; P less than 0.001) or 8 micrograms 5,7-DHT (sham, 1.35 +/- 0.06; MRL, 0.87 +/- 0.11 g/pup X day; P less than 0.001). Despite hypothalamic serotonin depletions of 15% and 55%, respectively, for the two doses of 5,7-DHT, there was no difference between sham and MRL animals in either basal or suckling-induced PRL release. When lesions were placed on day 1 of lactation (L) so that killing on day 7-L corresponded to the early maximal neurotoxin effect, MRL mothers still showed litter growth decrements (0.37 +/- 0.07; sham, 0.98 +/- 0.08 g/pup X day; P less than 0.001) and normal PRL values. When maternal behavior was examined, MRL animals exhibited a higher incidence of abnormal behaviors (failure to retrieve pups, cannibalism, and failure to initiate suckling during a 1-h test period; Fisher's exact P, Sham vs. MRL, less than 0.01, less than 0.05, and 0.15, respectively) than sham animals or animals with 5,7-DHT lesions in the dorsal raphe nucleus or superior colliculus. In addition, suckling behavior scores, determined from daily suckling behavior observations, were lowest in the MRL group and correlated with litter growth only in this group (r = 0.789; P less than 0.01). These data suggest that serotonergic elements in the MR nucleus play an obligatory role in maintaining normal maternal behavior during lactation, but they are not involved in suckling

  14. Heterogeneous chloride homeostasis and GABA responses in the median preoptic nucleus of the rat

    PubMed Central

    Grob, Magali; Mouginot, Didier

    2005-01-01

    The median preoptic nucleus (MnPO) is an integrative structure of the hypothalamus receiving periphery-derived information pertinent to hydromineral and cardiovascular homeostasis. In this context, excitability of MnPO neurones is controlled by fast GABAergic, glutamatergic and angiotensinergic projection from the subfornical organ (SFO). Taking advantage of a brain slice preparation preserving synaptic connection between the SFO and the MnPO, and appropriate bicarbonate-free artificial cerebrospinal fluid (CSF), we investigated a possible implication of an active outward Cl− transport in regulating efficacy of the GABAA receptor-mediated inhibitory response at the SFO–MnPO synapse. When somata of the MnPO neurones was loaded with 18 mm chloride, stimulation of the SFO evoked outward inhibitory postsynaptic currents (IPSCs) in 81% of the MnPO neurones held at −60 mV. Accordingly, EIPSC was found 25 mV hyperpolarized from the theoretical value calculated from the Nernst equation, indicating that IPSC polarity and amplitude were driven by an active Cl− extrusion system in these neurones. EIPSC estimated with gramicidin-based perforated-patch recordings amounted −89.2 ± 4.3 mV. Furosemide (100 μm), a pharmacological compound known to block the activity of the neurone-specific K+–Cl− cotransporter, KCC2, reversed IPSC polarity and shifted EIPSC towards its theoretical value. Presence of the KCC2 protein in the MnPO was further detected with immunohistochemistry, revealing a dense network of KCC2-positive intermingled fibres. In the presence of a GABAB receptor antagonist, high-frequency stimulation (5 Hz) of the SFO evoked a train of IPSCs or inhibitory postsynaptic potentials (IPSPs), whose amplitude was maintained throughout the sustained stimulation. Contrastingly, similar 5 Hz stimulation carried out in the presence of furosemide (50 μm) evoked IPSCs/IPSPs, whose amplitude collapsed during the high-frequency stimulation. Similar reduction in

  15. Behavioural pain-related disorders and contribution of the saphenous nerve in crush and chronic constriction injury of the rat sciatic nerve.

    PubMed

    Attal, N; Filliatreau, G; Perrot, S; Jazat, F; Di Giamberardino, L; Guilbaud, G

    1994-11-01

    This study evaluated the pain-related behaviours induced by 2 models of peripheral sciatic nerve injuries in the rat: transient nerve crush and chronic constriction injury (CCI). Various lesions of the saphenous nerve were performed in order to investigate the role of saphenous innervation in behavioural disorders induced by these nerve injuries. Behavioural testing included assessment of responses to phasic stimulation (mechanical and thermal) and observation of 'spontaneous' pain-related behaviour. Results confirmed that the model of CCI induces marked and prolonged phasic and spontaneous pain-related disorders (up to week 7). Rats with crush injury exhibited moderate and transient hyperalgesia and allodynia to mechanical and thermal stimulation on the lesioned side (with a maximum at day 3 and a recovery by week 1). Section plus ligation of the ipsilateral saphenous nerve on the day of surgery prevented nociceptive behaviours and induced persistent mechanical and thermal anaesthesia or hypoesthesia of the lesioned paw in both models (lasting up to 3-4 weeks). Section without ligation of the saphenous nerve induced comparable results in rats with sciatic crush, but did not significantly modify nociceptive behaviours in rats with CCI. These data emphasise the role of adjacent saphenous nerve in the mechanisms of pain-related disorders induced by these peripheral nerve lesions. On the contralateral paw, pain-related modifications were also observed in both models, suggesting that unilateral nerve lesions induce remote modifications extending beyond the site of the injured nerve. PMID:7892028

  16. Restoring motor control and sensory feedback in people with upper extremity amputations using arrays of 96 microelectrodes implanted in the median and ulnar nerves

    NASA Astrophysics Data System (ADS)

    Davis, T. S.; Wark, H. A. C.; Hutchinson, D. T.; Warren, D. J.; O'Neill, K.; Scheinblum, T.; Clark, G. A.; Normann, R. A.; Greger, B.

    2016-06-01

    Objective. An important goal of neuroprosthetic research is to establish bidirectional communication between the user and new prosthetic limbs that are capable of controlling >20 different movements. One strategy for achieving this goal is to interface the prosthetic limb directly with efferent and afferent fibres in the peripheral nervous system using an array of intrafascicular microelectrodes. This approach would provide access to a large number of independent neural pathways for controlling high degree-of-freedom prosthetic limbs, as well as evoking multiple-complex sensory percepts. Approach. Utah Slanted Electrode Arrays (USEAs, 96 recording/stimulating electrodes) were implanted for 30 days into the median (Subject 1-M, 31 years post-amputation) or ulnar (Subject 2-U, 1.5 years post-amputation) nerves of two amputees. Neural activity was recorded during intended movements of the subject’s phantom fingers and a linear Kalman filter was used to decode the neural data. Microelectrode stimulation of varying amplitudes and frequencies was delivered via single or multiple electrodes to investigate the number, size and quality of sensory percepts that could be evoked. Device performance over time was assessed by measuring: electrode impedances, signal-to-noise ratios (SNRs), stimulation thresholds, number and stability of evoked percepts. Main results. The subjects were able to proportionally, control individual fingers of a virtual robotic hand, with 13 different movements decoded offline (r = 0.48) and two movements decoded online. Electrical stimulation across one USEA evoked >80 sensory percepts. Varying the stimulation parameters modulated percept quality. Devices remained intrafascicularly implanted for the duration of the study with no significant changes in the SNRs or percept thresholds. Significance. This study demonstrated that an array of 96 microelectrodes can be implanted into the human peripheral nervous system for up to 1 month durations. Such an

  17. An alternative to nerve repair using an antioxidant compound: a histological study in rats.

    PubMed

    Salles, Marcos B; Gehrke, Sergio A; Koo, Samuel; Allegrini, Sergio; Rogero, Sizue O; Ikeda, Tamiko I; Cruz, Áurea S; Shinohara, Elio H; Yoshimoto, Marcelo

    2015-01-01

    The fascicular composition and organisation of the inferior alveolar nerve (IAN) were determined to confirm the microarchitecture of the IAN bundles into each of the mandibular teeth, including the composition of the mental nerve. The aim of this study was to evaluate peripheral nerve repair after the application of an antioxidant compound to the damaged nerve tissue to elevate the concentration and bioavailability of elements capable of favouring tissue repair. Twenty-five Wistar rats were divided into groups: The Control 1 (Ctl 1) (n = 5) animals had the ischiatic nerve exposed with no suture injury and were sacrificed at 30 days post-operatively. The Control 2 (Ctl 2) (n = 10) animals had the ischiatic nerve exposed, and the nerve was injured using suture in three distinct regions. In the experimental (Exp) animals (n = 10), an antioxidant organic compound was applied to the nerve injury site. The animals with nerve injury (Ctl2 and Exp group) were sacrificed at 15 and 30 days post-operatively. The histological analysis showed less degeneration in the Exp group at 15 and 30 days post-operatively. Nerve neoformation forming a connection between the distal and proximal suture sites was observed in the experimental group. This study presented an alternative to nerve repair using an antioxidant compound. PMID:25578694

  18. [Neuropathic pain intensity depends on the degree of peripheral nerve injury in the rat].

    PubMed

    Abuduhadeer, Tayier

    2004-12-01

    Partial peripheral nerve injury produces a persistent neuropathic pain which is difficult to relieve. In order to determine whether different degrees of peripheral nerve injury are related with the severity of neuropathic pain, we examined pain-related behaviors, histological changes and NGF in the skin in rats treated with different types of spinal nerve injury: tight ligation of the left L5 spinal nerve, incomplete ligation of the left L4 and L5 spinal nerves and incomplete crush of the left L4 and L5 spinal nerves. In all model rats, the thresholds of paw withdrawal in response to mechanical and heat stimuli began to decrease on the injured side 1 day after the operation, and the decreases in the thresholds persisted for more than 1 month. Incomplete ligation and incomplete crush of the left L4 and L5 spinal nerves caused more severe allodynia and hyperalgesia than tight ligation of the left L5 spinal nerve on the injured side. In rats treated with incomplete crush, the threshold of withdrawal response to mechanical or heat stimuli was improved on day 32 after the operation as compared with that on day 15. Histological analysis revealed that about 80% of the fibers in the sciatic nerve were injured after incomplete ligation and incomplete crush of the left L4 and L5 spinal nerves on day 15, while about 50% of the fibers were damaged by tight ligation of the left L5 spinal nerve. In accordance with pain-relieving, the sciatic nerve fibers regenerated to about 50% of the number of the intact sciatic nerve fibers on day 32 in the crush model. Nerve growth factor (NGF) in the skin of the hindpaw on the injured side was accumulated after incomplete ligation and incomplete crush of the left L4 and L5 spinal nerves, but not tight ligation of the left L5 spinal nerve, on day 15 after the operation, possibly due to impairment of transport via unmyelinated primary afferents. Regeneration of the sciatic nerve alleviated the accumulation of NGF in the injured side hindpaw

  19. The Effect of Sildenafil on Recuperation from Sciatic Nerve Injury in Rats

    PubMed Central

    Korkmaz, Mehmet Fatih; Parlakpınar, Hakan; Ceylan, Mehmet Fethi; Ediz, Levent; Şamdancı, Emine; Kekilli, Ersoy; Sağır, Mustafa

    2016-01-01

    Background: Severe functional and anatomical defects can be detected after the peripheral nerve injury. Pharmacological approaches are preferred rather than surgical treatment in the treatment of nerve injuries. Aims: The aim of this study is to perform histopathological, functional and bone densitometry examinations of the effects of sildenafil on nerve regeneration in a rat model of peripheral nerve crush injury. Study Design: Animal experiment. Methods: The study included a total of thirty adult Sprague-Dawley rats that were divided into three groups of ten rats each. In all rats, a crush injury was created by clamping the right sciatic nerve for one minute. One day before the procedure, rats in group 1 were started on a 28-day treatment consisting of a daily dose of 20 mg/kg body weight sildenafil citrate given orally via a nasogastric tube, while the rats in group 2 were started on an every-other-day dose of 10 mg/kg body weight sildenafil citrate. Rats from group 3 were not administered any drugs. Forty-two days after the nerve damage was created, functional and histopathological examination of both sciatic nerves and bone densitometric evaluation of the extremities were conducted. Results: During the rotarod test, rats from group 3 spent the least amount of time on the rod compared to the drug treatment groups at speeds of 20 rpm, 30 rpm and 40 rpm. In addition, the duration for which each animal could stay on the rod throughout the accelerod test significantly reduced in rats from group 3 compared to rats from groups 1 and 2 in the 4-min test. For the hot-plate latency time, there were no differences among the groups in either the basal level or after sciatic nerve injury. Moreover, there was no significant difference between the groups in terms of the static sciatic index (SSI) on the 42nd day (p=0.147). The amplitude was better evaluated in group 1 compared to the other two groups (p<0.05). Under microscopic evaluation, we observed the greatest amount of

  20. Nerve involvement in fluid transport in the inflamed rat jejunum.

    PubMed Central

    Jodal, M; Wingren, U; Jansson, M; Heidemann, M; Lundgren, O

    1993-01-01

    Net fluid transport was measured in denervated jejunal segments of rats infected with larvae of Nippostrongylus brasiliensis. On days 6-9 after nematode inoculation, when the jejunal segment exhibited macroscopic and microscopic signs of inflammation, net fluid absorption was noticeably attenuated compared with control, and in eight of 26 experiments a net fluid secretion was seen. To determine whether enteric nerves participated in the response, intravenous hexamethonium (10 mg/kg body weight) was given or lidocaine (1% solution) was placed on the serosa of the intestinal segment. Both drugs significantly reduced fluid secretion or increased fluid absorption. The effect was more pronounced the lower the rate of fluid absorption or the higher the rate of fluid secretion. The inflammatory response influenced intestinal fluid transport partly via activation of the enteric nervous system. It was estimated that 50-60% of the change in fluid transport caused by the parasite could be ascribed to activation of intramural nervous reflexes. The effect of hexamethonium indicates that a cholinergic synapse is present in the secretory nervous reflux activated by inflammation. Experiments were also performed on animals on days 11-14 after infection when the nematodes had been expelled from the animal. A large net fluid absorption was then recorded. PMID:8244137

  1. An alternative video footprint analysis to assess functional loss following injury to the rat sciatic nerve.

    PubMed

    Bervar, M

    2002-01-01

    The rat sciatic nerve is a well-established animal model for the study of recovery from peripheral nerve injuries. Footprint analysis is the most widely used non-invasive method of measuring functional recovery after injury in this model. We describe a new, alternative video analysis of standing (or static footprint video analysis) to assess functional loss following injury to the rat sciatic nerve, while the animal is standing or at periodic rest on a flat transparent surface. We found that this alternative video analysis is technically easier to perform than the corresponding footprint video analysis while walking, but still preserves all advantages of video versus conventional ink track method: i.e. few non-measurable footprints, better repeatability, high accuracy and more precise quantification of the degree of functional loss after sciatic nerve injury in the rat. PMID:12514995

  2. Retrograde axonal transport of /sup 125/I-nerve growth factor in rat ileal mesenteric nerves. Effect of streptozocin diabetes

    SciTech Connect

    Schmidt, R.E.; Plurad, S.B.; Saffitz, J.E.; Grabau, G.G.; Yip, H.K.

    1985-12-01

    The retrograde axonal transport of intravenously (i.v.) administered /sup 125/I-nerve growth factor (/sup 125/I-NGF) was examined in mesenteric nerves innervating the small bowel of rats with streptozocin (STZ) diabetes using methods described in detail in the companion article. The accumulation of /sup 125/I-NGF distal to a ligature on the ileal mesenteric nerves of diabetic animals was 30-40% less than in control animals. The inhibition of accumulation of /sup 125/I-NGF in diabetic animals was greater at a ligature tied 2 h after i.v. administration than at a ligature tied after 14 h, which suggests that the diabetic animals may have a lag in initiation of NGF transport in the terminal axon or retardation of transport at some site along the axon. The /sup 125/I-NGF transport defect was observed as early as 3 days after the induction of diabetes, a time before the development of structural axonal lesions, and did not worsen at later times when dystrophic axonopathy is present. Both the ileal mesenteric nerves, which eventually develop dystrophic axonopathy in experimental diabetes, and the jejunal mesenteric nerves, which never develop comparable structural alterations, showed similar /sup 125/I-NGF transport deficits, suggesting that the existence of the transport abnormality does not predict the eventual development of dystrophic axonal lesions. Autoradiographic localization of /sup 125/I-NGF in the ileal mesenteric nerves of animals that had been diabetic for 11-13 mo demonstrated decreased amounts of /sup 125/I-NGF in transit in unligated paravascular nerve fascicles. There was, however, no evidence for focal retardation of transported /sup 125/I-NGF at the sites of dystrophic axonal lesions.

  3. Radiation Pretreatment Does Not Protect the Rat Optic Nerve From Elevated Intraocular Pressure–Induced Injury

    PubMed Central

    Johnson, Elaine C.; Cepurna, William O.; Choi, Dongseok; Choe, Tiffany E.; Morrison, John C.

    2015-01-01

    Purpose. Optic nerve injury has been found to be dramatically reduced in a genetic mouse glaucoma model following exposure to sublethal, head-only irradiation. In this study, the same radiation treatment was used prior to experimental induction of elevated intraocular pressure (IOP) to determine if radiation is neuroprotective in another glaucoma model. Methods. Episcleral vein injection of hypertonic saline was used to elevate IOP unilaterally in two groups of rats: (1) otherwise untreated and (2) radiation pretreated, n > 25/group. Intraocular pressure histories were collected for 5 weeks, when optic nerves were prepared and graded for injury. Statistical analyses were used to compare IOP history and nerve injury. The density of microglia and macrophages in two nerve head regions was determined by Iba1 immunolabeling. Results. Mean and peak IOP elevations were not different between the two glaucoma model groups. Mean optic nerve injury grades were not different in glaucoma model optic nerves and were equivalent to approximately 35% of axons degenerating. Nerves selected for lower mean or peak IOP elevations did not differ in optic nerve injury. Similarly, nerves selected for lower injury grade did not differ in IOP exposure. By multiple regression modeling, nerve injury grade was most significantly associated with mean IOP (P < 0.002). There was no significant effect of radiation treatment. Iba1+ cell density was not altered by radiation treatment. Conclusions. In contrast to previous observations in a mouse genetic glaucoma model, head-only irradiation offers the adult rat optic nerve no protection from optic nerve degeneration due to chronic, experimentally induced IOP elevation. PMID:25525172

  4. Reduced Renshaw Recurrent Inhibition after Neonatal Sciatic Nerve Crush in Rats

    PubMed Central

    Shu, Liang; Su, Jingjing; Jing, Lingyan; Huang, Ying; Di, Yu; Peng, Lichao; Liu, Jianren

    2014-01-01

    Renshaw recurrent inhibition (RI) plays an important gated role in spinal motion circuit. Peripheral nerve injury is a common disease in clinic. Our current research was designed to investigate the change of the recurrent inhibitory function in the spinal cord after the peripheral nerve crush injury in neonatal rat. Sciatic nerve crush was performed on 5-day-old rat puppies and the recurrent inhibition between lateral gastrocnemius-soleus (LG-S) and medial gastrocnemius (MG) motor pools was assessed by conditioning monosynaptic reflexes (MSR) elicited from the sectioned dorsal roots and recorded either from the LG-S and MG nerves by antidromic stimulation of the synergist muscle nerve. Our results demonstrated that the MSR recorded from both LG-S or MG nerves had larger amplitude and longer latency after neonatal sciatic nerve crush. The RI in both LG-S and MG motoneuron pools was significantly reduced to virtual loss (15–20% of the normal RI size) even after a long recovery period upto 30 weeks after nerve crush. Further, the degree of the RI reduction after tibial nerve crush was much less than that after sciatic nerve crush indicatig that the neuron-muscle disconnection time is vital to the recovery of the spinal neuronal circuit function during reinnervation. In addition, sciatic nerve crush injury did not cause any spinal motor neuron loss but severally damaged peripheral muscle structure and function. In conclusion, our results suggest that peripheral nerve injury during neonatal early development period would cause a more sever spinal cord inhibitory circuit damage, particularly to the Renshaw recurrent inhibition pathway, which might be the target of neuroregeneration therapy. PMID:24778886

  5. Renal sympathetic nerve activity is increased in monosodium glutamate induced hyperadipose rats.

    PubMed

    da Silva Mattos, Alexandro Márcio; Xavier, Carlos Henrique; Karlen-Amarante, Marlusa; da Cunha, Natália Veronez; Fontes, Marco Antonio Peliky; Martins-Pinge, Marli Cardoso

    2012-08-01

    The literature suggests that both obesity and hypertension are associated with increased sympathetic nerve activity. In the present study we evaluated the renal sympathetic nerve activity (RSNA), mean arterial pressure (MAP) and heart rate (HR) in hyperadipose rats induced by neonatal administration of monosodium glutamate (MSG). Neonatal Wistar male rats were injected with MSG (4 mg/g body weight ID) or equimolar saline (control) for 5 days. At 90th day, all rats were anesthetized (urethane 1.4 g/kg) and prepared for MAP, HR and renal sympathetic nerve activity recordings. The anesthetized MSG rats presented baseline hypertension and increased baseline RSNA compared with control. Our results suggest the involvement of the renal sympathetic nervous system in the physiopathology of the MSG obesity. PMID:22705582

  6. Main trajectories of nerves that traverse and surround the tympanic cavity in the rat

    PubMed Central

    WEIJNEN, J. A. W. M.; SURINK, S.; VERSTRALEN, M. J. M.; MOERKERKEN, A.; DE BREE, G. J.; BLEYS, R. L. A. W.

    2000-01-01

    To guide surgery of nerves that traverse and surround the tympanic cavity in the rat, anatomical illustrations are required that are topographically correct. In this study, maps of this area are presented, extending from the superior cervical ganglion to the otic ganglion. They were derived from observations that were made during dissections using a ventral approach. Major blood vessels, bones, transected muscles of the tongue and neck and supra and infrahyoid muscles serve as landmarks in the illustrations. The course of the mandibular, facial, glossopharyngeal, vagus, accessory and hypoglossal nerves with their branches, and components of the sympathetic system, are shown and discussed with reference to data available in the literature. Discrepancies in this literature can be clarified and new data are presented on the trajectories of several nerves. The course of the tympanic nerve was established. This nerve originates from the glossopharyngeal nerve, enters the tympanic cavity, crosses the promontory, passes the tensor tympani muscle dorsally, and continues its route intracranially to the otic ganglion as the lesser petrosal nerve after intersecting with the greater petrosal nerve. Auricular branches of the glossopharyngeal and of the vagus nerve were noted. We also observed a pterygopalatine branch of the internal carotid nerve, that penetrates the tympanic cavity and courses across the promontory. PMID:11005717

  7. Extracting structural features of rat sciatic nerve using polarization-sensitive spectral domain optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Islam, M. Shahidul; Oliveira, Michael C.; Wang, Yan; Henry, Francis P.; Randolph, Mark A.; Park, B. Hyle; de Boer, Johannes F.

    2012-05-01

    We present spectral domain polarization-sensitive optical coherence tomography (SD PS-OCT) imaging of peripheral nerves. Structural and polarization-sensitive OCT imaging of uninjured rat sciatic nerves was evaluated both qualitatively and quantitatively. OCT and its functional extension, PS-OCT, were used to image sciatic nerve structure with clear delineation of the nerve boundaries to muscle and adipose tissues. A long-known optical effect, bands of Fontana, was also observed. Postprocessing analysis of these images provided significant quantitative information, such as epineurium thickness, estimates of extinction coefficient and birefringence of nerve and muscle tissue, frequency of bands of Fontana at different stretch levels of nerve, and change in average birefringence of nerve under stretched condition. We demonstrate that PS-OCT combined with regular-intensity OCT (compared with OCT alone) allows for a clearer determination of the inner and outer boundaries of the epineurium and distinction of nerve and muscle based on their birefringence pattern. PS-OCT measurements on normal nerves show that the technique is promising for studies on peripheral nerve injury.

  8. The onset and rate of myelination in six peripheral and autonomic nerves of the rat.

    PubMed Central

    Schäfer, K; Friede, R L

    1988-01-01

    A light and electron microscopic study was carried out of the numbers of myelinated fibres in 6 nerves of the rat for 7 age groups from birth to 73 weeks. The hypoglossal nerve and the mandibular branch of the facial nerve had short and early myelination periods, essentially complete by the second week. The glossopharyngeal nerve and the sympathetic rami communicantes myelinated late and over a protracted period. Myelination of the rami communicantes continued up to 20 weeks, followed by a marked loss of fibres in the 73 week animals. Intercostal and saphenous nerves had intermediary patterns. There was evidence of subpopulations myelinating at different times. Measurements of myelin sheath thickness showed variations of relative sheath thickness with age, between nerves and for subpopulations of nerves. Late myelination corresponded to relatively thin myelin sheaths. Statistical two-stage-density cluster analysis by computer was used for analysing complex fibre populations. The developmental changes of three subpopulations of the intercostal nerve are documented. Nerves also differed in their rates of axon growth. The increment in axon calibre was small and late for sympathetic fibres. Intercostal and facial nerve fibres had rapid axon growth with different growth rates for subpopulations. PMID:3248966

  9. Altered protein phosphorylation in sciatic nerve from rats with streptozocin-induced diabetes

    SciTech Connect

    Schrama, L.H.; Berti-Mattera, L.N.; Eichberg, J.

    1987-11-01

    The effect of experimental diabetes on the phosphorylation of proteins in the rat sciatic nerve was studied. Nerves from animals made diabetic with streptozocin were incubated in vitro with (/sup 32/P)orthophosphate and divided into segments from the proximal to the distal end, and proteins from each segment were then separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The principal labeled species were the major myelin proteins, P0, and the basic proteins. After 6 wk of diabetes, the incorporation of isotope into these proteins rose as a function of distance along the nerve in a proximal to distal direction and was significantly higher at the distal end compared with incorporation into nerves from age-matched controls. The overall level of isotope uptake was similar in nerves from diabetic animals and weight-matched controls. The distribution of /sup 32/P among proteins also differed in diabetic nerve compared with both control groups in that P0 and the small basic protein accounted for a greater proportion of total label incorporated along the entire length of nerve. In contrast to intact nerve, there was no significant difference in protein phosphorylation when homogenates from normal and diabetic nerve were incubated with (/sup 32/P)-gamma-ATP. The results suggest that abnormal protein phosphorylation, particularly of myelin proteins, is a feature of experimental diabetic neuropathy and that the changes are most pronounced in the distal portion of the nerve.

  10. Bridging nigrostriatal pathway with fibroblast growth factor-primed peripheral nerves and fetal ventral mesencephalon transplant recuperates from deficits in parkinsonian rats.

    PubMed

    Chiang, Yung-Hsiao; Lin, Shinn-Zong; Zhou, Feng C

    2006-01-01

    Previous studies have indicated that the nigrostriatal dopaminergic (DA) pathway can be reconstructed in hemiparkinsonian rats with a bridge transplantation technique involving fetal ventral mesencephalic transplants and glial cell line-derived neurotrophic factor. In this study, we examined if the nigrostriatal pathway can be restored by combining peripheral nervous tissue with the fetal ventral mesencephalon transplants. Adult rats were injected with 6-hydroxydopamine into left median forebrain bundle. Those with marked rotational behavior, which has been previously shown to indicate complete DA dennervtion, were used for transplant treatments. One month after the lesion, fetal ventral mesencephalic cells were transplanted into the nigral region followed by nigral-striatal grafting of peripheral nerves as a bridge. The bridging nerves (sciatic or intercostals) were pretreated with basic fibrous growth factor (nerve+bFGF+) or Hank's saline (nerve+bFGF-). We found that (a) animals receiving transplants of VM and bFGF+ nerve had a reduction in rotational behavior; (b) animals receiving bFGF-- nerve bridge only had a partial improvement in rotation. Reinnervation of tyrosine hydroxylase (TH)-immunoreactive (ir) fibers into the striatum was found in both of the above groups with more innervation in the former than in the latter. No TH-ir fibers in lesioned striatum or reduction in rotational behavior were found in animals receiving VM only, or VM plus bFGF. Taken together, our data indicate that peripheral nerve, with the aid of bFGF, greatly facilitates the reconstitution of the TH pathway from nigra to striatum and improves motor function in hemiparkinsonian rats. PMID:17121158

  11. Effects of metabolic syndrome on the ultrastructure of the femoral nerve in aging rats.

    PubMed

    Rodrigues de Souza, Romeu; Gama, Eliane F; El-Razi Neto, Semaan; Maldonado, Diogo

    2015-10-01

    The aim of the present study was to characterize the morphometry of the femoral nerve in aging rats with metabolic syndrome compared to controls. Systolic blood pressure and fasting plasma glucose were measured, and myelinated and unmyelinated fibers in the femoral nerves were quantitatively assessed under electron microscopy. Aging rats exposed to a regimen of metabolic syndrome developed elevation of plasma glucose concentration, mild hypertension and polyneuropathy characterized by a decrease in myelin fiber area, axon diameter, myelin sheath thickness and myelin fiber loss in the femoral nerve. The histogram of size distribution for myelinated fibers and axons from the aging rats of the control group was bimodal. For aging MS animals, the histogram turned out to be unimodal. The ultrastructure of unmyelinated fibers and of Schwann cells in 18-month-old rats was well preserved. Granules of lipofuscin were seen in unmyelinated fiber axons of 18-month-old rats with MS. The damage percentage of the large myelinated fibers has increased significantly in 18-month-old and 18-month-old (MS) rats in relation to the controls. No significant difference was observed among the groups for the g-ratio. Comparing the three groups, the number of neurotubules and neurofilaments in myelinated fibers of 18-month-old rats with MS was significantly smaller than for the groups of 18-month-old and 14-month-old rats. The overall changes seen in the femoral nerve from aging rats seem minor compared to the changes in the aging rats with MS, suggesting that long-term MS accelerates the progressive modifications in peripheral nerves that develop in old age. PMID:25866014

  12. Histological Study of Bone Marrow and Umbilical Cord Stromal Cell Transplantation in Regenerating Rat Peripheral Nerve

    PubMed Central

    Zarbakhsh, Sam; Goudarzi, Nasim; Shirmohammadi, Maryam; Safari, Manouchehr

    2016-01-01

    Objective Bone marrow and umbilical cord stromal cells are multipotential stem cells that have the ability to produce growth factors that play an important role in survival and generation of axons. The goal of this study was to evaluate the effects of the two different mesenchymal stem cells on peripheral nerve regeneration. Materials and Methods In this experimental study, a 10 mm segment of the left sciatic nerve of male Wistar rats (250-300 g) was removed with a silicone tube interposed into this nerve gap. Bone marrow stromal cells (BMSCs) and human umbilical cord stromal cells (HUCSCs) were respectively obtained from rat and human. The cells were sepa- rately cultured and transplanted into the nerve gap. The sciatic nerve regeneration was evaluated by immunohistochemistry, and light and electron microscopy. Moreover, histo- morphology of the gastrocnemius muscle was observed. Results The nerve regeneration in the BMSCs and HUCSCs groups that had received the stem cells was significantly more favorable than the control group. In addition, the BM- SCs group was significantly more favorable than the HUCSCs group (P<0.05). Conclusion The results of this study suggest that both homograft BMSCs and het- erograft HUCSCs may have the potential to regenerate peripheral nerve injury and transplantation of BMSCs may be more effective than HUCSCs in rat. PMID:26862526

  13. Alpha-lipoic acid loaded in chitosan conduit enhances sciatic nerve regeneration in rat

    PubMed Central

    Azizi, Saeed; Heshmatian, Behnam; Amini, Keyvan; Raisi, Abbas; Azimzadeh, Mohammad

    2015-01-01

    Objective(s): To investigate the effect of topical administration of alpha-lipoic acid into chitosan conduit on peripheral nerve regeneration using a rat sciatic nerve transection model. Materials and Methods: Forty five Wistar rats were divided into three experimental groups randomly. A 10-mm gap of sciatic nerve was bridged with a chitosan conduit following surgical preparation and anesthesia. In treatment group, the conduit was filled with 30 µl alpha-lipoic acid (10 mg/kg/bw).It was filled with 30 µl phosphate buffered saline solution in control group. In Sham group sciatic nerve was just exposed. Results: The recovery of nerve function was faster in treatment group than in control, at 4 and 8 weeks after surgery (P-value<0.05). Conduction velocity was better in treatment group than in control group at 4 and 12 weeks (P-value<0.05). Recovery index was higher in treatment group than the control group, 8 weeks after surgery (P-value <0.05). Greater nerve fiber diameter, axon diameter, and myelin sheath thickness were observed in treatment group compared to control group at 8 and 12 weeks after surgery (P-value<0.05). The immunoreactivity of regenerated axons and myelin sheath in treatment group were far more similar to sham group. Conclusion: Alpha-lipoic acid when loaded in a chitosan conduit could improve transected sciatic nerve regeneration in rat. PMID:25945234

  14. Acrylamide administration alters protein phosphorylation and phospholipid metabolism in rat sciatic nerve

    SciTech Connect

    Berti-Mattera, L.N.; Eichberg, J.; Schrama, L.; LoPachin, R.M. )

    1990-05-01

    The effects of ACR on protein phosphorylation and phospholipid metabolism were assessed in rat sciatic nerve. After 5 days of ACR administration (50 mg/kg/day) an increase in the incorporation of 32P into phosphatidylinositol-4,5-bisphosphate, phosphatidylinositol-4-phosphate, and phosphatidylcholine was detected in proximal sciatic nerve segments. In contrast, no changes in phospholipid metabolism were observed in distal segments. After 9 days of ACR treatment when neurotoxicological symptoms were clearly apparent, a generalized increase in radiolabel uptake into phospholipids was noted exclusively in proximal nerve regions. ACR-induced increases in phospholipid metabolism were toxicologically specific since comparable administration of MBA (108 mg/kg/day X 5 or 9 days) produced only minor changes. ACR intoxication was also associated with a rise in sciatic nerve protein phosphorylation. After 9 days of ACR treatment, phosphorylation of beta-tubulin, P0, and several unidentified proteins (38 and 180 kDa) was increased in distal segments. In contrast, chronic administration of MBA caused increases in phosphorylation of beta-tubulin and the major myelin proteins of proximal nerve segments. In cell free homogenates prepared from sciatic nerves of treated and control rats, MBA caused an increase in phosphorylation of major myelin proteins similar to its effect in intact proximal nerve segments. The most striking effect observed in nerve homogenates of ACR-treated rats was a marked decrease in phosphorylation of an 80-kDa protein. Addition of ACR (1 mM) to homogenates of normal nerve had no effect on protein phosphorylation. Our results indicate that changes in the phosphorylation of phospholipids and proteins in sciatic nerve might be a component of the neurotoxic mechanism of ACR.

  15. Temperature-controlled optical stimulation of the rat prostate cavernous nerves.

    PubMed

    Tozburun, Serhat; Hutchens, Thomas C; McClain, Michael A; Lagoda, Gwen A; Burnett, Arthur L; Fried, Nathaniel M

    2013-06-01

    Optical nerve stimulation (ONS) may be useful as a diagnostic tool for intraoperative identification and preservation of the prostate cavernous nerves (CN), responsible for erectile function, during prostate cancer surgery. Successful ONS requires elevating the nerve temperature to within a narrow range (~42 to 47°C) for nerve activation without thermal damage to the nerve. This preliminary study explores a prototype temperature-controlled optical nerve stimulation (TC-ONS) system for maintaining a constant (±1°C) nerve temperature during short-term ONS of the rat prostate CNs. A 150-mW, 1455-nm diode laser was operated in continuous-wave mode, with and without temperature control, during stimulation of the rat CNs for 15 to 30 s through a fiber optic probe with a 1-mm-diameter spot. A microcontroller opened and closed an in-line mechanical shutter in response to an infrared sensor, with a predetermined temperature set point. With TC-ONS, higher laser power settings were used to rapidly and safely elevate the CNs to a temperature necessary for a fast intracavernous pressure response, while also preventing excessive temperatures that would otherwise cause thermal damage to the nerve. With further development, TC-ONS may provide a rapid, stable, and safe method for intraoperative identification and preservation of the prostate CNs. PMID:23733025

  16. Temperature-controlled optical stimulation of the rat prostate cavernous nerves

    NASA Astrophysics Data System (ADS)

    Tozburun, Serhat; Hutchens, Thomas C.; McClain, Michael A.; Lagoda, Gwen A.; Burnett, Arthur L.; Fried, Nathaniel M.

    2013-06-01

    Optical nerve stimulation (ONS) may be useful as a diagnostic tool for intraoperative identification and preservation of the prostate cavernous nerves (CN), responsible for erectile function, during prostate cancer surgery. Successful ONS requires elevating the nerve temperature to within a narrow range (˜42 to 47°C) for nerve activation without thermal damage to the nerve. This preliminary study explores a prototype temperature-controlled optical nerve stimulation (TC-ONS) system for maintaining a constant (±1°C) nerve temperature during short-term ONS of the rat prostate CNs. A 150-mW, 1455-nm diode laser was operated in continuous-wave mode, with and without temperature control, during stimulation of the rat CNs for 15 to 30 s through a fiber optic probe with a 1-mm-diameter spot. A microcontroller opened and closed an in-line mechanical shutter in response to an infrared sensor, with a predetermined temperature set point. With TC-ONS, higher laser power settings were used to rapidly and safely elevate the CNs to a temperature necessary for a fast intracavernous pressure response, while also preventing excessive temperatures that would otherwise cause thermal damage to the nerve. With further development, TC-ONS may provide a rapid, stable, and safe method for intraoperative identification and preservation of the prostate CNs.

  17. EFFECTS OF HYPERGLYCEMIA ON RAT CAVERNOUS NERVE AXONS: A FUNCTIONAL AND ULTRASTRUCTURAL STUDY

    PubMed Central

    Zotova, Elena G.; Schaumburg, Herbert H.; Raine, Cedric S.; Cannella, Barbara; Tar, Moses; Melman, Arnold; Arezzo, Joseph C.

    2008-01-01

    The present study explored parallel changes in the physiology and structure of myelinated (Aδ) and unmyelinated (C) small diameter axons in the cavernous nerve of rats associated with streptozotocin-induced hyperglycemia. Damage to these axons is thought to play a key role in diabetic autonomic neuropathy and erectile dysfunction, but their pathophysiology has been poorly studied. Velocities in slow conducting fibers were measured by applying multiple unit procedures; histopathology was evaluated with both light and electron microscopy. To our knowledge, these are the initial studies of slow nerve conduction velocities in the distal segments of the cavernous nerve. We report that hyperglycemia is associated with a substantial reduction in the amplitude of the slow conducting response, as well as a slowing of velocities within this very slow range (<2.5 m/sec). Even with prolonged hyperglycemia (> 4 months), histopathological abnormalities were mild and limited to the distal segments of the cavernous nerve. Structural findings included dystrophic changes in nerve terminals, abnormal accumulations of glycogen granules in unmyelinated and preterminal axons, and necrosis of scattered smooth muscle fibers. The onset of slowing of velocity in the distal cavernous nerve occurred subsequent to slowing in somatic nerves in the same rats. The functional changes in the cavernous nerve anticipated and exceeded the axonal degeneration detected by morphology. The physiologic techniques outlined in these studies are feasible in most electrophysiologic laboratories and could substantially enhance our sensitivity to the onset and progression of small fiber diabetic neuropathy. PMID:18687329

  18. Ginkgo biloba extract (EGb 761) promotes peripheral nerve regeneration and neovascularization after acellular nerve allografts in a rat model.

    PubMed

    Zhu, Zhaowei; Zhou, Xiang; He, Bo; Dai, Ting; Zheng, Canbin; Yang, Chuang; Zhu, Shuang; Zhu, Jiakai; Zhu, Qingtang; Liu, Xiaolin

    2015-03-01

    This study aimed to investigate whether or not ginkgo biloba extract (EGb 761) enhances peripheral nerve regeneration and vascularization after repair using acellular nerve allografts (ANA). Seventy-two Sprague-Dawley rats were randomly divided into three experimental groups: a unilateral 15-mm sciatic nerve defect was created and repaired with an autologous graft (autograft group); the same defect was repaired with an 18 mm ANA with an i.p. injection of normal saline for 10 days (saline group); and in the final group, the same defect was repaired with an 18 mm ANA with an i.p. injection of EGb 761 for 10 days (EGb 761 group). Axon outgrowth and vascularization were evaluated by immunocytochemistry 14 days post-implantation. The expression of genes associated with angiogenesis was analyzed by real-time polymerase chain reaction (PCR) seven days post-implantation. Compared with the saline group, rats in the EGb 761 group significantly increased the number of myelinated fibers and the average diameter of the nerves within the graft. There is no significant difference between the EGb 761 group and the autograft group. The expression of CD34 and NF200 was significantly higher in the EGb 761 group than in the saline group. Additionally, EGb 761 treatment increased the expression of several angiogenesis-related genes, including Vegf, SOX18, Prom 1, and IL-6. In conclusion, ANA repair with EGb 761 treatment demonstrates effects on peripheral nerve regeneration and vascularization that are equal to those of autologous graft repair, and that are superior to ANA repair alone. PMID:25319407

  19. A simple method for reducing autotomy in rats after peripheral nerve lesions.

    PubMed

    Sporel-Ozakat, R E; Edwards, P M; Hepgul, K T; Savas, A; Gispen, W H

    1991-02-01

    Experiments using peripheral nerve lesions (crush or transection) in rats to study repair processes are hampered by the tendency for the animals to attack the limb in which the peripheral nerves are damaged (autotomy). In this paper we describe a simple method which significantly reduces the incidence of autotomy after peripheral nerve lesions. The method consists of painting the hind paws of operated rats with a commercially available non-toxic lotion, which is used to discourage nail-biting and thumb-sucking in humans. Although the method is not absolute, it was extremely beneficial in our experiments, since the number of animals that had to be taken out of the experiment due to severe autotomy was greatly reduced. We believe that this method may prove to be as beneficial to other investigators who are using experimental peripheral nerve lesions to study the regenerative aspects of the nervous system. PMID:2062121

  20. Continuous-wave vs. pulsed infrared laser stimulation of the rat prostate cavernous nerves

    NASA Astrophysics Data System (ADS)

    Tozburun, Serhat; Cilip, Christopher M.; Lagoda, Gwen A.; Burnett, Arthur L.; Fried, Nathaniel M.

    2011-03-01

    Optical nerve stimulation has recently been developed as an alternative to electrical nerve stimulation. However, recent studies have focused primarily on pulsed delivery of the laser radiation and at relatively low pulse rates. The objective of this study is to demonstrate faster optical stimulation of the prostate cavernous nerves using continuouswave (CW) infrared laser radiation, for potential diagnostic applications. A Thulium fiber laser (λ = 1870 nm) was used for non-contact optical stimulation of the rat prostate cavernous nerves, in vivo. Optical nerve stimulation, as measured by an intracavernous pressure (ICP) response in the penis, was achieved with the laser operating in either CW mode, or with a 5-ms pulse duration at 10, 20, 30, 40, 50, and 100 Hz. Successful optical stimulation was observed to be primarily dependent on a threshold nerve temperature (42-45 °C), not an incident fluence, as previously reported. CW optical nerve stimulation provides a significantly faster ICP response time using a laser with lower power output than pulsed stimulation. CW optical nerve stimulation may therefore represent an alternative mode of stimulation for intra-operative diagnostic applications where a rapid response is critical, such as identification of the cavernous nerves during prostate cancer surgery.

  1. Reactive oxygen species (ROS) mediates non-freezing cold injury of rat sciatic nerve

    PubMed Central

    Geng, Zhiwei; Tong, Xiaoyan; Jia, Hongjuan

    2015-01-01

    Non-freezing cold injury is an injury characterized by neuropathy, developing when patients expose to cold environments. Reactive oxygen species (ROS) has been shown as a contributing factor for the non-freezing cold nerve injury. However, the detailed connections between non-freezing cold nerve injury and ROS have not been described. In order to investigate the relationship between non-freezing cold nerve injury and reactive oxygen species, we study the effects of two cooling methods-the continuous cooling and the intermittent cooling with warming intervals-on rat sciatic nerves. Specifically, we assess the morphological changes and ROS production of the sciatic nerves underwent different cooling treatments. Our data shows both types of cooling methods cause nerve injury and ROS production. However, despite of identical cooling degree and duration, the sciatic nerves processed by intermittent cooling with warming intervals present more ROS production, severer reperfusion injury and pathological destructions than the sciatic nerves processed by continuous cooling. This result indicates reactive oxygen species, as a product of reperfusion, facilitates non-freezing cold nerve injury. PMID:26629065

  2. Minimally Invasive Approach to the Lingual and Hypoglossal Nerves in the Adult Rat.

    PubMed

    Doyle, Edward John; Phillips, Grady W; Gratton, Michael Anne; Long, John P; Varvares, Mark A

    2016-06-01

    Surgical manipulation of the sensory and motor nerves of the rat tongue is often employed in studies evaluating the oral cavity functions of mastication and deglutition. A noninvasive, atraumatic approach that will then facilitate sufficient manipulation of these structures is required. In this study, we detail an approach that consistently allows identification of the hypoglossal (motor) and lingual (sensory) nerves of the rat. Six Wistar rats (250-500 g) were anesthetized and dissected either as fresh tissue (N = 3) or following transcardial perfusion with 4% paraformaldehyde (N = 3). Both fixed and non-fixed specimens of the rat head and neck were incised in the right submandibular region. The first animal in each group was used to gain a basic understanding of the regional muscular anatomy with reference to the hypoglossal and lingual nerves. Subsequent animals were used for the development of an efficient and minimally invasive approach to these nerves. The resultant approach begins as an incision through skin and platysma, followed by medial reflection of the digastric muscle. This allows visualization of the hypoglossal nerve in the region of the bifurcation of the common trunk into medial and lateral subdivisions. Next, the lingual nerve dissection is approached by reflection rostrally of the transversus mandibularis muscle and a caudal reflection of the mylohyoid muscle. This dissection reveals the geniohyoid muscle which when separated bluntly using forceps, exposes the lingual nerve. The anatomical approach described and illustrated herein will aid investigators in consistent identification of these two nerves as fundamental methods of their projects. PMID:26633569

  3. Role of oxidative stress in surgical cavernous nerve injury in a rat model.

    PubMed

    Wang, Hui; Ding, Xie-Gang; Li, Shi-Wen; Zheng, Hang; Zheng, Xin-Min; Navin, Shrestha; Li, Lu; Wang, Xing-Huan

    2015-06-01

    This study investigates the role of oxidative stress in surgical cavernous nerve (CN) injury in a rat model. Eighty-four male Sprague-Dawley rats were randomly divided into three groups: group 1, sham-operated rats; group 2, bilateral CN-crushed rats; and group 3, bilateral CN-transection-and-sutured-immediately rats. Oxidative stress was evaluated by malondialdehyde levels, super oxide dismutase (SOD) activities, and glutathione peroxidase (GPX) activities in serum. Erectile function was assessed by CN electrostimulation at 3 months with mean maximal intracavernous pressure (ICP) and maximal ICP per mean arterial pressure. Nerve injury was assessed by toluidine blue staining of CNs and nicotinamide adenine dinucleotide phosphate (NADPH)-diaphorase staining of penile tissue. GPX protein expression and nitrotyrosine-3 (NT-3) levels in penile tissue were measured. Erectile function and the number of myelinated axons of CNs and NADPH-diaphorase-positive nerve fibers were statistically decreased between groups, from sham to crush to transection. For markers, both nerve-injury groups showed increased oxidative stress markers at early time points, with the transection group showing greater oxidative stress than the crushed group and values normalizing to sham levels by week 12. GPX expression and NT-3 levels in penile tissue were in concordance with the results of SOD and GPX. These results show that oxidative stress plays an important role in injured CNs, and different methods of CN injury can lead to different degrees of oxidative stress in a rat model. PMID:25597854

  4. Topography of Synchronization of Somatosensory Evoked Potentials Elicited by Stimulation of the Sciatic Nerve in Rat

    PubMed Central

    Qu, Xuefeng; Yan, Jiaqing; Li, Xiaoli; Zhang, Peixun; Liu, Xianzeng

    2016-01-01

    Purpose: Traditionally, the topography of somatosensory evoked potentials (SEPs) is generated based on amplitude and latency. However, this operation focuses on the physical morphology and field potential-power, so it suffers from difficulties in performing identification in an objective manner. In this study, measurement of the synchronization of SEPs is proposed as a method to explore brain functional networks as well as the plasticity after peripheral nerve injury. Method: SEPs elicited by unilateral sciatic nerve stimulation in twelve adult male Sprague-Dawley (SD) rats in the normal group were compared with SEPs evoked after unilateral sciatic nerve hemisection in four peripheral nerve injured SD rats. The characterization of synchronized networks from SEPs was conducted using equal-time correlation, correlation matrix analysis, and comparison to randomized surrogate data. Eigenvalues of the correlation matrix were used to identify the clusters of functionally synchronized neuronal activity, and the participation index (PI) was calculated to indicate the involvement of each channel in the cluster. The PI value at the knee point of the PI histogram was used as a threshold to demarcate the cortical boundary. Results: Ten out of the twelve normal rats showed only one synchronized brain network. The remaining two normal rats showed one strong and one weak network. In the peripheral nerve injured group, only one synchronized brain network was found in each rat. In the normal group, all network shapes appear regular and the network is largely contained in the posterior cortex. In the injured group, the network shapes appear irregular, the network extends anteriorly and posteriorly, and the network area is significantly larger. There are considerable individual variations in the shape and location of the network after peripheral nerve injury. Conclusion: The proposed method can detect functional brain networks. Compared to the results of the traditional SEP

  5. Choline Acetyltransferase Activity in Striatum of Neonatal Rats Increased by Nerve Growth Factor

    NASA Astrophysics Data System (ADS)

    Mobley, William C.; Rutkowski, J. Lynn; Tennekoon, Gihan I.; Buchanan, Karen; Johnston, Michael V.

    1985-07-01

    Some neurodegenerative disorders may be caused by abnormal synthesis or utilization of trophic molecules required to support neuronal survival. A test of this hypothesis requires that trophic agents specific for the affected neurons be identified. Cholinergic neurons in the corpus striatum of neonatal rats were found to respond to intracerebroventricular administration of nerve growth factor with prominent, dose-dependent, selective increases in choline acetyltransferase activity. Cholinergic neurons in the basal forebrain also respond to nerve growth factor in this way. These actions of nerve growth factor may indicate its involvement in the normal function of forebrain cholinergic neurons as well as in neurodegenerative disorders involving such cells.

  6. Dynamic observation of biomechanic properties of sciatic nerve at the suture site in rats following repairing.

    PubMed

    Jiang, Baoguo; Zhang, Peixun; Yan, Jiazhi; Zhang, Hongbo

    2008-01-01

    To observe the biomechanic properties of the sciatic nerve at the suture site following repairing in rats. The right sciatic nerves of 40 white Sprague-Dawley 300~350 gm rats were exposed, cut and then repaired with 10-0 nylon sutures with four stitches, laced in the epineurium 0, 1, 3, and 6 weeks after operation, the tensile strength of the sciatic nerves were measured, and the data analyzed statistically. The load elongation curves for both the normal unoperated and operated nerves had similar shape. There were significant differences between the tensile strength of the 0th and the 1st, 3rd, and 6th weeks (P < 0.01). No significant difference was found among the 1st, 3rd, and 6th weeks. The tensile strength of the injured nerves recovered 48% of the normal nerve in the 1st week and 54% in 6 weeks after repairing. It may be concluded that the injured nerves can acquire mostly tensile strength stability in 1 week quickly and can maintain this relative tensile strength stability in 6 weeks. PMID:18293160

  7. [Neurons with Different Neurotransmitters in Embryonic Neocortical Allografts in the Rat Sciatic Nerve].

    PubMed

    Petrova, E S

    2016-01-01

    Different subsets of interneurons in the Wistar rat neocortex and in neocortical transplants developing in a damaged nerve were identified by the following immunohistochemical markers: glutamate decarboxylase (GAD 67) for GABAergic nerve cells, NO-synthase (NOS) for NO-ergic neurons, choline acetyltransferase (ChAT) for cholinergic cells, and tyrosine hydroxylase for catecholaminergic structures. Twenty-eight days after surgery, individual GAD 67-ir, NO-ir, ChAT-ir, and very rarely TH-ir cells were detected in the graft. It was shown that the number of GAD 67-ir neurons per unit area in the grafts was less than in the rat neocortex P20. PMID:27396173

  8. A new method of measuring functional recovery after crushing the peripheral nerves in unanesthetized and unrestrained rats.

    PubMed

    Hasegawa, K

    1978-02-15

    The distances between the first and fifth digits and between the second and fourth digits of the rat's hind paw were measured after crushing the sciatic nerve. The distances between the digits recovered significantly faster in weak nerve crushing than in strong crushing, and faster in distal nerve crushing than in proximal crushing. These results suggest that this method is available for evaluating the functional recovery after nerve crushing. PMID:624375

  9. Changes of nitric oxide synthase-containing nerve fibers and parameters for oxidative stress after unilateral cavernous nerve resection or manuplation in rat penis.

    PubMed

    Ozkara, Hamdi; Alan, Cabir; Atukeren, Pinar; Uyaner, Ilhan; Demirci, Cihan; Gümüştaş, M Koray; Alici, Bulent

    2006-06-30

    After pelvic surgeries such as radical prostatectomy, two major complications--urinary incontinence and erectile dysfunction (ED) may occur. Etiologies for ED are multiple pathologic mediators/systems. Oxidative stress, which is known to be induced after surgical trauma, could be a cause of ED. The purposes of in this study are to investigate the effect of unilateral manipulation/ dissection and resection of the cavernous nerve (neurotomy) to NOS (nitric oxide synthase)-containing nerve fibers and pressure after electro stimulation in rat corpus cavernosum, and to determine whether these procedures would produce oxidative stress within rat cavernous tissue 3 weeks and 6 months after the operation. Male rats were divided into 5 groups. Rats in groups 1 and 2 underwent unilateral cavernous nerve manipulation and sacrificed 3 weeks and 6 months after the operation, respectively. Rats in groups 3 and 4 underwent unilateral neurotomy of a 5-mm. segment of the cavernous nerve, and they were sacrificed 3 weeks and 6 months after nerve ablation, respectively. Group 5 rats were control animals for biochemical analysis. Intracavernous pressure following electro stimulation reduced is significantly 3 weeks after unilateral resection, as compared to that of the manipulated nerve (P < 0.05), and it recovered 6 months after neurotomy. The recovery was also confirmed by NADPH (nicotinamide adenine dinucleotide phosphate) diaphorase staining in neurotomy groups. Lipid peroxidation, which is an indicater of oxidative stress, was determined by measuring thiobarbituric acid reacting substance (TBARS) levels and superoxide dismutase (SOD) activity. These markers indicated that unilateral cavernous nerve manipulation or resection produced oxidative stress within rat corpus cavernosum. Oxidative stress was more prominent 3 weeks after unilateral neurotomy (P < 0.05). Also, compared to the control animal group, oxidative stress was observed three weeks after manipulation of unilateral

  10. Activation of sensory nerves participates in stress-induced histamine release from mast cells in rats.

    PubMed

    Huang, Z L; Mochizuki, T; Watanabe, H; Maeyama, K

    1999-08-01

    To elucidate the mechanism by which stress induces rapid histamine release from mast cells, Wistar rats, pretreated as neonates with capsaicin, were subjected to immobilization stress for 2 h, and histamine release was measured in paws of anesthetized rats by using in vivo microdialysis after activation of sensory nerves by electrical or chemical stimulation. Immobilization stress studies indicated that in control rats stress induced a 2.7-fold increase in the level of plasma histamine compared to that in freely moving rats. Whereas pretreatment with capsaicin significantly decreased stress-induced elevation of plasma histamine. Microdialysis studies showed that electrical stimulation of the sciatic nerve resulted in a 4-fold increase of histamine release in rat paws. However, this increase was significantly inhibited in rats pretreated with capsaicin. Furthermore, injection of capsaicin into rat paw significantly increased histamine release in a dose-dependent manner. These results suggest that activation of sensory nerves participates in stress-induced histamine release from mast cells. PMID:10462124

  11. Local and remote immune-mediated inflammation after mild peripheral nerve compression in rats.

    PubMed

    Schmid, Annina B; Coppieters, Michel W; Ruitenberg, Marc J; McLachlan, Elspeth M

    2013-07-01

    After experimental nerve injuries that extensively disrupt axons, such as chronic constriction injury, immune cells invade the nerve, related dorsal root ganglia (DRGs), and spinal cord, leading to hyperexcitability, raised sensitivity, and pain. Entrapment neuropathies, such as carpal tunnel syndrome, involve minimal axon damage, but patients often report widespread symptoms. To understand the underlying pathology, a tube was placed around the sciatic nerve in 8-week-old rats, leading to progressive mild compression as the animals grew. Immunofluorescence was used to examine myelin and axonal integrity, glia, macrophages, and T lymphocytes in the nerve, L5 DRGs, and spinal cord after 12 weeks. Tubes that did not constrict the nerve when applied caused extensive and ongoing loss of myelin, together with compromise of small-, but not large-, diameter axons. Macrophages and T lymphocytes infiltrated the nerve and DRGs. Activated glia proliferated in DRGs but not in spinal cord. Histologic findings were supported by clinical hyperalgesia to blunt pressure and cold allodynia. Tubes that did not compress the nerve induced only minor local inflammation. Thus, progressive mild nerve compression resulted in chronic local and remote immune-mediated inflammation depending on the degree of compression. Such neuroinflammation may explain the widespread symptoms in patients with entrapment neuropathies. PMID:23771220

  12. Histopathological changes in the periphery of the sciatic nerve of rats after knee joint immobilization.

    PubMed

    Yoshida, Shinya; Matsuzaki, Taro; Kamijo, Akio; Araki, Yoshitaka; Sakamoto, Makoto; Moriyama, Shigenori; Hoso, Masahiro

    2013-05-01

    [Purpose] This study was performed to investigate the histological changes that occur in the periphery of the sciatic nerve in rats undergoing knee immobilization. [Subjects and Methods] 29 male 9-week-old Wistar rats were divided randomly into a control group (C group, n = 7) and an immobilized group (I group, n = 22). The animals in the I group had the left knee joint immobilized in maximal flexion with plaster casts for two weeks. After the experimental period, we obtained cross-sections of tissues from the center of the left thigh, and the periphery of the sciatic nerve was observed under an optical microscope after hematoxylin-eosin staining. [Results] In contrast to the rats of C group, the rats in I group showed adherence between the bundle of nerve fibers and perineurium, as well as thickening of the perineurium. These histological changes were statistically significant. [Conclusions] Immobilization of the knee joints of rats resulted in characteristic histological changes in the connective tissue around the sciatic nerve. PMID:24259816

  13. Swim therapy reduces mechanical allodynia and thermal hyperalgesia induced by chronic constriction nerve injury in rats

    PubMed Central

    Shen, Jun; Fox, Lyle E.; Cheng, Jianguo

    2013-01-01

    Objective Neuropathic pain is common and often difficult to treat because it generally does not respond well to the currently available pain medications or nerve blocks. Recent studies in both humans and animals have suggested that exercise may induce a transient analgesia and reduce acute pain in normal healthy individuals. We examined whether swim therapy could alleviate neuropathic pain in rats. Design Rats were trained to swim over a two week period in warm water. After the rats were trained, neuropathic pain was induced by constricting the right sciatic nerve and regular swimming was resumed. The sensitivity of each hind paw was monitored using the Hargreaves test and von Frey test to evaluate the withdrawal response thresholds to heat and touch. Results The paw ipsilateral to the nerve ligation expressed pain-like behaviors including thermal hyperalgesia and mechanical allodynia. Regular swim therapy sessions significantly reduced the mechanical allodynia and thermal hyperalgesia. Swim therapy had little effect on the withdrawal thresholds for the contralateral paw. In addition, swim therapy alone did not alter the thermal or mechanical thresholds of normal rats. Conclusions The results suggest that regular exercise, including swim therapy, may be an effective treatment for neuropathic pain caused by nerve injuries. This study, showing that swim therapy reduces neuropathic pain behavior in rats, provides a scientific rationale for clinicians to test the efficacy of exercise in the management of neuropathic pain. It may prove to be a safe and cost-effective therapy in a variety of neuropathic pain states. PMID:23438327

  14. Nerve growth factor antibody exacerbates neuropathological signs of experimental allergic encephalomyelitis in adult lewis rats.

    PubMed

    Micera, A; Properzi, F; Triaca, V; Aloe, L

    2000-05-01

    In this study, experimental allergic encephalomyelitis (EAE) rats and rats exhibiting EAE expressing high circulating anti-nerve growth factor antibody were daily monitored for clinical signs and chronic relapses. Eighty-five days after EAE induction, blood, spinal cord and brain stem were used for histological examination, nerve growth factor (NGF) and brain derived neurotrophic factor (BDNF) evaluation. The results showed that NGF-deprived rats display more severe clinical signs of disease. These effects were associated with a significant reduction of NGF in the brain stem and spinal cord but not of BDNF, which decreased only in spinal cord. These observations provide additional support to the hypothesis of a protective NGF role in rats exhibiting EAE. PMID:10713350

  15. Atorvastatin is beneficial for muscle reinnervation after complete sciatic nerve section in rats.

    PubMed

    Cloutier, Frédéric-Charles; Rouleau, Dominique M; Hébert-Davies, Jonah; Beaumont, Pierre H; Beaumont, Eric

    2013-12-01

    Nerve regeneration and functional recovery are often incomplete after peripheral neurotmetic lesion. Atorvastatin has been shown to be neuroprotective after transient ischaemia or traumatic injury. The aim of this study was to establish if systemic administration of Atorvastatin could improve functional muscle reinnervation after complete sciatic nerve section. Sixteen female Sprague-Dawley rats were used in this study. After a complete right sciatic nerve section, end-to-end microsuture repair was performed and fibrin glue was added. Three groups were studied: (1) sutures (S) + fibrin glue (F) only + saline administration for 14 days; (2) S+F+Atorvastatin administration for 14 days; and (3) uninjured nerve. Five months later, the sciatic nerve and the gastrocnemius muscle were isolated to perform in vivo electrophysiological measurements. Better kinematics was observed in atorvastatin-treated rats 5 months after its administration. Indeed, a larger excursion of the hip-ankle-toe angle during walking was observed. This effect was associated with the preservation of electromyographic activity (2.91 mV vs 0.77 mV) and maximal muscle force (85.1 g vs 28.6 g) on stimulation of the proximal nerve section. Five months after a neurotmetic lesion, the recovery is incomplete when using suture and fibrin glue only. Furthermore, the systemic administration of Atorvastatin for 14 days after lesion was beneficial in improving locomotion capability associated with the re-establishment of muscle strength and EMG activity. PMID:23848426

  16. S1 nerve is the most efficient nerve rootlet innervating the anal canal and rectum in rats

    PubMed Central

    Fu, Kai; Luo, Pengbo; Zheng, Xianyou; Zhu, Xiaozhong; Wang, Lei; Chai, Yimin

    2015-01-01

    Autonomic and somatic components participate in the defecation process in mammals, combining signals from the brainstem and forebrain. The innervation pattern involved in micturition in rats has been well studied, while defecation has been less studied. The aim of the present study was to identify the most important sensory and motor nerves of the anal canal and rectum involved in defecation. The amplitudes of evoked potential of the anal canal and rectum were higher when L6 and S1 ventral rootlets were stimulated, compared with the other segments (ANOVA and Tukey’s post hoc test, all P < 0.05). The S1 segment was more strongly cholera toxin subunit B conjugated to horseradish peroxidase (CB-HRP) positive compared with the other segments (ANOVA and Tukey’s post hoc test, P < 0.05). Ventral spinal rootlets of L6 and S1 mainly contributed to the pressure change in the anal canal and rectum when the ventral spinal rootlets from L5 to S3 were stimulated electrically. In conclusion, many afferent and efferent nerves innervate the anal canal and rectum and are involved in defecation, but the S1 nerve rootlet could be the most efficient one. These results could provide a basis for defecation reconstruction, especially for patients with spinal cord injuries. PMID:26260583

  17. Early social isolation provokes electrophysiological and structural changes in cutaneous sensory nerves of adult male rats.

    PubMed

    Segura, Bertha; Melo, Angel I; Fleming, Alison S; Mendoza-Garrido, Maria Eugenia; González del Pliego, Margarita; Aguirre-Benitez, Elsa L; Hernández-Falcón, Jesús; Jiménez-Estrada, Ismael

    2014-12-01

    Sensory and social deprivation from the mother and littermates during early life disturbs the development of the central nervous system, but little is known about its effect on the development of the peripheral nervous system. To assess peripheral effects of early isolation, male rat pups were reared artificially in complete social isolation (AR); reared artificially with two same-age conspecifics (AR-Social); or reared by their mothers and with littermates (MR). As adults, the electrophysiological properties of the sensory sural (SU) nerve were recorded. We found that the amplitude and normalized area (with respect to body weight) of the compound action potential (CAP) response provoked by single electrical pulses of graded intensity in the SU nerves of AR animals were shorter than the CAP recorded in SU nerves from MR and AR-Social animals. The slope of the stimulus-response curve of AR SU nerves was smaller than that of the other nerves. The histological characterization of axons in the SU nerves was made and showed that the myelin thickness of axons in AR SU nerves was significant lower (2-7µm) than that of the axons in the other nerves. Furthermore, the area and axon diameter of SU nerves of both AR and AR-Social animals were significant lower than in MR animals. This is the first report to show that maternal and littermate deprivation by AR disturbs the development of the myelination and electrophysiological properties of axons in the SU nerve; the replacement of social cues prevents most of the effects. PMID:24897933

  18. Inhomogeneous derangement of cardiac autonomic nerve control in diabetic rats.

    PubMed

    Sanyal, Shamarendra Nath; Arita, Makoto; Ono, Katsushige

    2002-03-01

    The present study compared autonomic nervous function in Kob [Spontaneously Diabetic, Bio-Breeding (BB)] rats with control Wistar rats to determine the development of cardiac neuropathy in diabetic rats. Telemetric ECG signals were obtained from an ECG radio-transmitter placed in a dorsal subcutaneous pouch of male Kob and Wistar rats for 30min every 6h at a sample rate of 5kHz. Heart rate (HR) and HR variability (HRV) were analyzed in each group by power spectrograms obtained by a fast Fourier transform algorithm. RR interval, total power (TP), low frequency (LF) power (0.04-0.67 Hz), high frequency (HF) power (0.79-1.48 Hz) and LF/HF ratio were also measured. The Kob rats had lower HRV than the control Wistar rats; HR, TP, and HF power, but not the LF/HF ratio, in the Kob rats were significantly lower than those of the control rats (p<0.001). However, in the Kob rats the response of these parameters to a muscarinic antagonist (atropine: 2mg/kg) was left intact, but their response to a beta-adrenergic antagonist (propranolol: 4mg/kg) was impeded. Autonomic nervous control of HR in spontaneously diabetic rats was inhomogeneously deranged in terms of the balance in sympathetic and parasympathetic tone, not only in the baseline condition, but also in the regulatory systems, including postsynaptic receptor function. PMID:11922279

  19. Dithranol abolishes UCH-L1 immunoreactivity in the nerve fibers of the rat orofacial skin.

    PubMed

    Orojan, Ivan; Szigeti, Csaba; Varszegi, Szilvia; Dobo, Endre; Gulya, Karoly

    2006-11-22

    Dithranol has been used to treat psoriasis for decades. Although its beneficial effect may involve the induction of cutaneous inflammation, and inflammation often leads to damages in nerve fibers, these alterations are not well documented. Therefore, we investigated the effects of dithranol on the immunohistochemical characteristics of the cutaneous nerve fibers in the rat skin. Epidermal nerve fiber staining was achieved with ubiquitin carboxyl-terminal hydrolase L1 (UCH-L1) immunohistochemistry in the orofacial skin of control rats, rats treated with (a) dithranol for 5 days, (b) corticosteroid for 5 days following dithranol treatment for 5 days, and (c) corticosteroid for 5 days. The results revealed a complete loss of UCH-L1 immunoreactivity in the dithranol-treated animals. Topical application of corticosteroid onto the inflamed skin for 5 days reversed this effect: the UCH-L1 immunoreactivity was almost completely restored. Steroid treatment for 5 days did not change the appearance of the UCH-L1-immunoreactive nerve fibers. These findings were supported by Western blot analyses. We conclude that dithranol, incidentally similarly to psoriasis, causes inflammation and abolishes UCH-L1 immunoreactivity in the rat orofacial skin in a corticosteroid-reversible manner. This phenomenon may be due to the ability of dithranol to cause oxidative damage to the UCH-L1 protein, and to the antioxidant activity of the corticosteroids countering this effect. PMID:17011532

  20. DETERMINATION OF ACRYLAMIDE IN RAT SERUM AND SCIATIC NERVE BY GAS CHROMATOGRAPHY-ELECTRON-CAPTURE DETECTION

    EPA Science Inventory

    A modified method for the derivatization and analysis of acrylamide as 2-bromopropenamide by gas chromatography/electron capture detection was validated in serum and sciatic nerve from rats. he method was accurate and precise over the concentration range of 2240 to 74700 ppm (w/v...

  1. Acrolein depletes the neuropeptides CGRP and substance P in sensory nerves in rat respiratory tract.

    PubMed Central

    Springall, D R; Edginton, J A; Price, P N; Swanston, D W; Noel, C; Bloom, S R; Polak, J M

    1990-01-01

    The mammalian respiratory tract is densely innervated by autonomic and sensory nerves around airways and blood vessels. Subsets of these nerves contain a number of putative neurotransmitter peptides, such as substance P and calcitonin gene-related peptide (CGRP) in sensory nerves and vasoactive intestinal polypeptide (VIP), possibly serving autonomic functions. CGRP is also found in endocrine cells in rat airway epithelium. These peptides are all pharmacologically potent effectors of bronchial and vascular smooth muscle and bronchial secretion. Their functions in vivo are less well established. We have therefore examined the effects of inhaled acrolein, a sensory irritant, on three pulmonary neuropeptides: CGRP, substance P, and VIP. Groups of rats (n = 3 each) were exposed for 10 min to acrolein in air (Ct = 510, 1858, and 5693 mg.min/m3) or to air alone. Fifteen minutes later they were killed (pentabarbitone IP) and their respiratory tracts were dissected and fixed in 0.4% p-benzoquinone solution. Cryostat sections were stained by indirect immunofluorescence for a general nerve marker (PGP 9.5) and neuropeptides. The acrolein-treated animals had a dose-related decrease in tracheal substance P- and CGRP-immunoreactive nerve fibers compared with controls. No change was seen in total nerve fiber distribution and number (PGP 9.5) or VIP immunoreactivity, nor in CGRP-immunoreactive epithelial endocrine cells. It is concluded that the rat tracheal peptidergic nerves are a sensitive indicator of inhaled irritant substances. Their reduced immunoreactivity may be because of a release of sensory neuropeptides that could play a role in the physiological response to irritant or toxic compounds. Images FIGURE 4. a FIGURE 4. b FIGURE 5. a FIGURE 5. b FIGURE 6. a FIGURE 6. b FIGURE 7. a FIGURE 7. b FIGURE 7. c FIGURE 8. a FIGURE 8. b PMID:1696540

  2. Deciphering the Lipid Architecture of the Rat Sciatic Nerve Using Imaging Mass Spectrometry.

    PubMed

    Fernández, Roberto; Carriel, Víctor; Lage, Sergio; Garate, Jone; Díez-García, Javier; Ochoa, Begoña; Castro, Begoña; Alaminos, Miguel; Fernández, José A

    2016-05-18

    Knowledge on the normal structure and molecular composition of the peripheral nerves is essential to understand their pathophysiology and to select the regeneration strategies after injury. However, the precise lipid composition of the normal peripheral nerve is still poorly known. Here, we present the first study of distribution of individual lipids in the mature sciatic nerve of rats by imaging mass spectrometry. Both positive and negative ion modes were used to detect, identify and in situ map 166 molecular species of mainly glycerophospholipids, sphingomyelins, sulfatides, and diacyl and triacylglycerols. In parallel, lipid extracts were analyzed by LC-MS/MS to verify and complement the identification of lipids directly from the whole tissue. Three anatomical regions were clearly identified by its differential lipid composition: the nerve fibers, the connective tissue and the adipose tissue that surrounds the nerve. Unexpectedly, very little variety of phosphatidylcholine (PC) species was found, being by far PC 34:1 the most abundant species. Also, a rich composition on sulfatides was detected in fibers, probably due to the important role they play in the myelin cover around axons, as well as an abundance of storage lipids in the adipose and connective tissues. The database of lipids here presented for each region and for the whole sciatic nerve is a first step toward understanding the variety of the peripheral nerves' lipidome and its changes associated with different diseases and mechanical injuries. PMID:27043994

  3. PRGD/PDLLA conduit potentiates rat sciatic nerve regeneration and the underlying molecular mechanism.

    PubMed

    Li, Binbin; Qiu, Tong; Iyer, K Swaminathan; Yan, Qiongjiao; Yin, Yixia; Xie, Lijuan; Wang, Xinyu; Li, Shipu

    2015-07-01

    Peripheral nerve injury requires optimal conditions in both macro-environment and micro-environment for reestablishment. Though various strategies have been carried out to improve the macro-environment, the underlying molecular mechanism of axon regeneration in the micro-environment provided by nerve conduit remains unclear. In this study, the rat sciatic nerve of 10 mm defect was made and bridged by PRGD/PDLLA nerve conduit. We investigated the process of nerve regeneration using histological, functional and real time PCR analyses after implantation from 7 to 35 days. Our data demonstrated that the ciliary neurotrophic factor highly expressed and up-regulated the downstream signaling pathways, in the case of activated signals, the expressions of axon sprout relative proteins, such as tubulin and growth-associated protein-43, were strongly augmented. Taken together, these data suggest a possible mechanism of axon regeneration promoted by PRGD/PDLLA conduit, which created a micro-environment for enhancement of diffusion of neurotrophic factors secreted by the injured nerve stumps, and activation of molecular signal transduction involved in growth cone, to potentiate the nerve recovery. PMID:25934451

  4. Polyethylene glycol fusion repair prevents reinnervation accuracy in rat peripheral nerve.

    PubMed

    Robinson, Grant A; Madison, Roger D

    2016-07-01

    Functional recovery following a peripheral nerve injury is made easier when regenerating axons correctly reinnervate their original targets. Polyethylene glycol (PEG) has recently been used in attempts to fuse severed peripheral axons during suture-based repair, but an analysis of target selectivity following such repair has not been undertaken. The rat femoral nerve (in which muscle and cutaneous pathways comingle proximally but segregate distally into separate terminal nerve branches) is a convenient in vivo model for assessing motor neuron regeneration accuracy. The present study uses retrograde labeling of motor neurons to compare reinnervation accuracy after suture-based nerve repair with and without PEG fusion. The results show that adding PEG to the suture repair site blocked the preference of motor neurons to reinnervate correctly the distal terminal nerve branch to muscle that was seen with suture repair. Retrograde transport and diffusion studies also determined that PEG fusion allowed passage of probes across the repair site, as has previously been seen, but did not result in motor neuron labeling in the spinal cord. The results suggest that PEG fusion disrupts the beneficial trophic influence of muscle on motor neuron reinnervation accuracy normally seen after suture repair and that such fusion-based approaches may be best suited to nerve injuries in which accurate target reinnervation at the terminal nerve branch level is not a priority. © 2016 Wiley Periodicals, Inc. PMID:26994857

  5. Effect of long-term weightlessness on retina and optic nerve in tail-suspension rats

    PubMed Central

    Zhao, Hong-Wei; Zhao, Jun; Hu, Lian-Na; Liang, Jing-Nan; Shi, Yuan-Yuan; Nie, Chuang; Qiu, Chang-Yu; Nan, Xin-Shuai; Li, Yu-Xin; Gao, Fu-Lin; Liu, Yi; Dong, Yu; Luo, Ling

    2016-01-01

    AIM To evaluate the effect of long-term weightlessness on retina and optic nerve in tail-suspension (TS) rats. METHODS A stimulated weightlessness model was established by suspending rats' tail. After 12wk, the ultrastructure and the number of optic nerve axons were observed by transmission electron microscope. The number of survival retinal ganglion cells (RGCs) was calculated by fluorescent gold retrograde labeling. Retina cells apoptosis was detected by TUNEL staining. The function of optic nerve and retina was evaluated by the visual evoked potential (VEP) and oscillatory potentials (Ops). RESULTS The optic nerve axons were swollen and sparsely aligned, and the lamellar separation and myelin disintegration occurred after 12wk in TS rats. The density of optic nerve axons was 32.23±3.92 (vs 37.43±4.13, P=0.0145), the RGCs density was 1645±46 cells/mm2 (vs 1867±54 cells/mm2 P=0.0000), the incidence rate of retinal cells apoptosis was 5.38%±0.53% (vs 4.75%±0.54%, P=0.0238), the amplitude of VEP-P100 was 15.43±2.14 µV (vs 17.67±2.17 µV, P=0.0424), the latency of VEP-P100 was 69.05±5.34ms (vs 62.43±4.87ms P=0.0143) and the sum amplitude of Ops was 81.05±8.34 µV (vs 91.67±10.21 µV, P=0.0280) in TS group and the control group, respectively. CONCLUSION Long-term weightlessness can induce the ultrastructural changes and functional depress of the optic nerve, as well as retinal cell damages in TS rats. PMID:27366682

  6. Regeneration of putative sensory and sympathetic cutaneous nerve endings in the rat foot after sciatic nerve injury.

    PubMed

    Stankovic, N; Johansson, O; Hildebrand, C

    1996-01-01

    The present study examines the occurrence of calcitonin gene-related peptide-, substance P- and tyrosine hydroxylase-like immunoreactive profiles in glabrous and hairy foot skin from normal and nerve-injured rats. After neurotomy/suture, glabrous skin samples contain few calcitonin gene-related peptide-, substance P- and tyrosine hydroxylase-like immunoreactive profies. The number of calcitonin gene-related peptide- and substance P-like immunoreacive profiles in the epidermis is significantly subnormal. Hairy skin from these rats does also contain few calcitonin gene-related peptide-, substance P- and tyrosine hydroxylase-like immunoreactive profiles. In addition, the presence of epidermal calcitonin gene-related peptide-like imunoreactive profiles in glabrous skin is subnormal on the contralateral side. After nerve crush injury, the occurrence of calcitonin gene-related peptide-like, but not substance P-like, immunoreactive profiles in th epidermis of the glabrous skin is significantly subnormal. The occurrence of tyrosine hylase-like immnunoreactive fibres in relation to the digital artery is also subnormal. The occurrence in hairy skin of calcitonin gene-related peptide-like immunoreactive, substance P-like immunoreactive and tyrosine hydroxylase-like immunoreactive profiles is subnormal. In both skin types, the contralateral occurrence of such profiles is subjectively normal. These results show that the occurrence of calcitonin gene-related peptide-, substance P-, and tyrosine hydroxylase-like immunoreactive profiles in glabrous and hairy foot skin is clearly subnormal after neurotomy and suture and less abnormal after nerve crush. After neurotomy and suture the contralateral side is also affected. PMID:10970110

  7. Effects of prostaglandin E2 on cells cultured from the rat organum vasculosum laminae terminalis and median preoptic nucleus.

    PubMed

    Simm, B; Ott, D; Pollatzek, E; Murgott, J; Gerstberger, R; Rummel, C; Roth, J

    2016-01-28

    The time course of the induction of enzymes responsible for the formation of prostaglandin E2 (PGE2) after an inflammatory insult, in relation to the concomitant febrile response, suggests that peripherally generated PGE2 is involved in the induction of the early phase of fever, while centrally produced PGE2 exerts pyrogenic capacities during the later stages of fever within the hypothalamic median preoptic nucleus (MnPO). The actions of peripherally derived PGE2 on the brain might occur at the level of the organum vasculosum laminae terminalis (OVLT), which lacks a tight blood-brain barrier and is implicated in fever, while the effects of PGE2 within the MnPO might interfere with glutamatergic neurotransmission within a recently characterized central efferent pathway for the activation of cold-defence reactions. Using the fura-2 ratio imaging technique we, therefore, measured changes of the intracellular Ca(2+)-concentration in primary neuroglial microcultures of rat OVLT and MnPO stimulated with PGE2 and/or glutamate. In cultures from the OVLT, as opposed to those derived from the MnPO, substantial numbers of neurons (8% of 385), astrocytes (19% of 645) and microglial cells (28% of 43) directly responded to PGE2 with a transient increase of intracellular Ca(2+). The most pronounced effect of PGE2 on cells from MnPO microcultures was its modulatory influence on the strength of glutamate-induced Ca(2+)-signals. In 72 out of 512 neurons and in 105 out of 715 astrocytes PGE2 significantly augmented glutamate-induced Ca(2+)-signals. About 30% of these neurons were GABAergic. These observations are in agreement with putative roles of peripheral PGE2 as a directly acting circulating agent at the level of the OVLT, and of central MnPO-intrinsic PGE2 as an enhancer of glutamatergic neurotransmission, which causes disinhibition of thermogenic heat production, a crucial component for the manifestation of fever. In microcultures from both brain sites investigated incubation

  8. The neuroprotective effects of aspirin following crush injury to rat sciatic nerve

    PubMed Central

    Cui, Yi; Li, Jun; Zhu, Yueliang; Tang, Hui; He, Xiaoqing; Xu, Yongqing

    2015-01-01

    Aspirin has been reported to be neuroprotective and produce some benefits for central nervous system diseases. However, the possibility of using aspirin as a neuroprotective agent for peripheral nerve injuries has rarely been reported thus far. The aim of the present study was to investigate the possibly beneficial effects of aspirin on sciatic nerve crush injury therapy in rats. Crush injury animal model was prepared with Sprague-Dawley rats. The animals were evenly divided into high-dose aspirin group, low-dose aspirin group, and vehicle group. Aspirin solution or normal saline were intraperitoneally injected once a day for 28 days after sciatic nerve crush injury. A sham-operative group was also added as normal control. The results from walking track analysis and electrophysiological assessment indicated that motor functional recovery in the aspirin groups were better than that in the vehicle group. Morphometric analysis of regenerated nerves and Fluoro-Gold retrograde tracing demonstrated that axonal regeneration in the aspirin groups was superior to that in the vehicle group. Our findings suggest that aspirin might be used as a neuroprotective agent for treating peripheral nerve injuries. PMID:26770418

  9. Distribution of elements and water in peripheral nerve of streptozocin-induced diabetic rats

    SciTech Connect

    Lowery, J.M.; Eichberg, J.; Saubermann, A.J.; LoPachin, R.M. Jr. )

    1990-12-01

    Accumulating evidence suggests that alterations in Na, Ca, K, and other biologically relevant elements play a role in the mechanism of cell injury. The pathogenesis of experimental diabetic neuropathy is unknown but might include changes in the distribution of these elements in morphological compartments. In this study, this possibility was examined via electron-probe X-ray microanalysis to measure both concentrations of elements (millimoles of element per kilogram dry or wet weight) and cell water content (percent water) in frozen, unfixed, unstained sections of peripheral nerve from control and streptozocin-induced diabetic rats. Our results indicate that after 20 wk of experimental diabetes, mitochondria and axoplasm from myelinated axons of proximal sciatic nerve displayed diminished K and Cl content, whereas in tibial nerve, the intraaxonal levels of these elements increased. In distal sciatic nerve, mitochondrial and axoplasmic levels of Ca were increased, whereas other elemental alterations were not observed. These regional changes resulted in a reversal of the decreasing proximodistal concentration gradients for K and Cl, which exist in nondiabetic rat sciatic nerve. Our results cannot be explained on the basis of altered water. Highly distinctive changes in elemental distribution observed might be a critical component of the neurotoxic mechanism underlying diabetic neuropathy.

  10. Erythropoietin promotes peripheral nerve regeneration in rats by upregulating expression of insulin-like growth factor-1

    PubMed Central

    Wang, Wei; Li, Dongsheng; Li, Qing; Wang, Lei; Bai, Guang; Yang, Tao; Li, Qiang; Zhu, Zhitu

    2015-01-01

    Introduction Erythropoietin (EPO) has been shown to have beneficial effects on peripheral nerve damage, but its mechanism of action remains incompletely understood. In this study we hypothesized that EPO promotes peripheral nerve repair via neurotrophic factor upregulation. Material and methods Thirty adult male Wistar rats were employed to establish a sciatic nerve injury model. They were then randomly divided into two groups to be subjected to different treatment: 0.9% saline (group A) and 5000 U/kg EPO (group B). The walking behavior of rats was evaluated by footprint analysis, and the nerve regeneration was assessed by electron microscopy. The expression of insulin-like growth factor-1 (IGF-1) in the injured sciatic nerves was detected by immunohistochemical analysis. Results Compared to saline treatment, EPO treatment led to the growth of myelin sheath, the recovery of normal morphology of axons and Schwann cells, and higher density of myelinated nerve fibers. Erythropoietin treatment promoted the recovery of SFI in the injured sciatic nerves. In addition, EPO treatment led to increased IGF-1 expression in the injured sciatic nerves. Conclusions Erythropoietin may promote peripheral nerve repair in a rat model of sciatic nerve injury through the upregulation of IGF-1 expression. These findings reveal a novel mechanism underlying the neurotrophic effects of EPO. PMID:25995763

  11. Novel TRPM8 antagonist attenuates cold hypersensitivity after peripheral nerve injury in rats.

    PubMed

    Patel, Ryan; Gonçalves, Leonor; Newman, Robert; Jiang, Feng Li; Goldby, Anne; Reeve, Jennifer; Hendrick, Alan; Teall, Martin; Hannah, Duncan; Almond, Sarah; Brice, Nicola; Dickenson, Anthony H

    2014-04-01

    Abnormal cold sensitivity is a common feature of a range of neuropathies. In the murine somatosensory system, multiple aspects of cold sensitivity are dependent on TRPM8, both short term and in response to peripheral nerve injury. The specialized nature of cold-sensitive afferents and the restricted expression of TRPM8 render it an attractive target for the treatment of cold hypersensitivity. This current study examines the effect of a novel TRPM8 antagonist (M8-An) in naive and spinal nerve-ligated rats through behavioral and in vivo electrophysiological approaches. In vitro, M8-An inhibited icilin-evoked Ca(2+) currents in HEK293 cells stably expressing human TRPM8 with an IC(50) of 10.9 nM. In vivo, systemic M8-An transiently decreased core body temperature. Deep dorsal horn recordings were made in vivo from neurons innervating the hind paw. M8-An inhibited neuronal responses to innocuous and noxious cooling of the receptive field in spinal nerve-ligated rats but not in naive rats. No effect on neuronal responses to mechanical and heat stimulation was observed. In addition, M8-An also attenuated behavioral responses to cold but not mechanical stimulation after nerve ligation without affecting the uninjured contralateral response. The data presented here support a contribution of TRPM8 to the pathophysiology of cold hypersensitivity in this model and highlight the potential of the pharmacological block of TRPM8 in alleviating the associated symptoms. PMID:24472724

  12. Endothelin-1 impairs retrograde axonal transport and leads to axonal injury in rat optic nerve.

    PubMed

    Taniguchi, Takazumi; Shimazawa, Masamitsu; Sasaoka, Masaaki; Shimazaki, Atsushi; Hara, Hideaki

    2006-05-01

    The purpose of this study was to examine the effects of endothelin-1 (ET-1) on retrograde axonal transport in the rat optic nerve. Vehicle or ET-1 (0.2, 1, or 5 pmol/eye) were injected into the vitreous body in Sprague-Dawley rats. Retinal vessels were observed, using a fundus camera, before, and at 10 min, 3 days and 7 days after a single intravitreous injection. Two days after the injection, a neuronal tracer, fluoro gold, was administered via the superior colliculi to retrogradely label active retinal ganglion cells (RGCs). Five days after the tracer administration, retrogradely labeled RGCs were evaluated in the flat-mounted retina, and cross sections from each optic nerve were graded for injury by four independent, masked observers. ET-1 at 5 pmol/eye caused a significant constriction of retinal vessels (versus the vehicle-treated group) at 10 min after the injection. Intravitreous injection of ET-1 caused a dose-related decrease in the number of retrogradely labeled RGCs. Injection of 5 pmol/eye ET-1 led to a statistically significant decrease in the number of retrogradely labeled RGCs (versus the vehicle-treated group). ET-1 at 1 and 5 pmol/eye caused histological optic nerve damage (evaluated using a graded scale). The histological optic nerve damage correlated with the number of retrogradely labeled RGCs. In conclusion, a single intravitreous injection of ET-1 impaired retrograde axonal transport in the rat optic nerve and this impairment correlated with the histological optic nerve damage. PMID:16719791

  13. T Lymphocyte Subsets and Cytokines in Rats Transplanted with Adipose-Derived Mesenchymal Stem Cells and Acellular Nerve for Repairing the Nerve Defects

    PubMed Central

    Chen, Ou; Chu, Ting-gang; Ding, Jian; Yu, Qing

    2015-01-01

    Objective The aim of this study was to explore the immunity in rats transplanted with adipose-derived mesenchymal stem cells (ADSCs) and acellular nerve (ACN) for repairing sciatic nerve defects. Methods ADSCs were isolated from the adipose tissues of Wistar rats. Sprague-Dawley rats were used to establish a sciatic nerve defect model and then divided into four groups, according to the following methods : Group A, allogenic nerve graft; Group B, allograft with ACN; Group C, allograft ADSCs+ACN, and Group D, nerve autograft. Results At the day before transplantation and 3, 7, 14, and 28 days after transplantation, orbital venous blood of the Sprague-Dawley rats in each group was collected to detect the proportion of CD3+, CD4+, and CD8+ subsets using flow cytometry and to determine the serum concentration of interleukin-2 (IL-2), tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ) using enzyme-linked immunosorbent assay (ELISA). At each postoperative time point, the proportion of CD3+, CD4+, and CD8+ subsets and the serum concentration of IL-2, TNF-α, and IFN-γ in group C were all near to those in group B and group D, in which no statistically significant difference was observed. As compared with group A, the proportion of CD3+, CD4+, and CD8+ subsets and the serum concentration of IL-2, TNF-α, and IFN-γ were significantly reduced in group C (p<0.05). Conclusion The artificial nerve established with ADSCs and ACN has no obvious allograft rejection for repairing rat nerve defects. PMID:26361524

  14. Bone Marrow Mesenchymal Stem Cell and Vein Conduit on Sciatic Nerve Repair in Rats

    PubMed Central

    Seyed Foroutan, Kamal; Khodarahmi, Ali; Alavi, Hootan; Pedram, Sepehr; Baghaban Eslaminejad, Mohamad Reza; Bordbar, Sima

    2015-01-01

    Background: Peripheral nerve repair with sufficient functional recovery is an important issue in reconstructive surgery. Stem cells have attracted extensive research interest in recent years. Objectives: The purpose of this study was to compare the vein conduit technique, with and without the addition of mesenchymal stem cells in gap-less nerve injury repair in rats. Materials and Methods: In this study, 36 Wistar rats were randomly allocated to three groups: In the first group, nerve repair was performed with simple neurorrhaphy (control group), in the second group, nerve repair was done with vein conduit over site (vein conduit group) and in the third group, bone marrow stem cells were instilled into the vein conduit (stem cell group) after nerve repair with vein conduit over site. Six weeks after the intervention, the sciatic function index, electrophysiological study and histological examination were performed. Results: All animals tolerated the surgical procedures and survived well. The sciatic function index and latency were significantly improved in the vein conduit (P = 0.04 and 0.03, respectively) and stem cell group (P = 0.02 and 0.03, respectively) compared with the control group. No significant difference was observed in sciatic function and latency between the vein conduit and stem-cell groups. Moreover, histological analysis showed no significant difference in regenerative density between these two groups. Conclusions: The results of this study showed that the meticulous microsurgical nerve repair, which was performed using the vein tubulization induced significantly better sciatic nerve regeneration. However, the addition of bone marrow mesenchymal stem cell to vein conduit failed to promote any significant changes in regeneration outcome. PMID:25825699

  15. Different dose-dependent effects of ebselen in -sciatic nerve ischemia-reperfusion injury in rats

    PubMed Central

    Ozyigit, Filiz; Kucuk, Aysegul; Akcer, Sezer; Tosun, Murat; Kocak, Fatma Emel; Kocak, Cengiz; Kocak, Ahmet; Metineren, Hasan; Genc, Osman

    2015-01-01

    Ebselen is an organoselenium compound which has strong antioxidant and anti-inflammatory effects. We investigated the neuroprotective role of ebselen pretreatment in rats with experimental sciatic nerve ischemia-reperfusion (I/R) injury. Adult male Sprague Dawley rats were divided into four groups (N = 7 in each group). Before sciatic nerve I/R was induced, ebselen was injected intraperitoneally at doses of 15 and 30 mg/kg. After a 2 h ischemia and a 3 h reperfusion period, sciatic nerve tissues were excised. Tissue levels of malondialdehyde (MDA) and nitric oxide (NO), and activities of superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT) were measured. Sciatic nerve tissues were also examined histopathologically. The 15 mg/kg dose of ebselen reduced sciatic nerve damage and apoptosis (P < 0.01), levels of MDA, NO, and inducible nitric oxide synthase (iNOS) positive cells (P < 0.01, P < 0.05, respectively), and increased SOD, GPx, and CAT activities (P < 0.001, P < 0.01, P < 0.05, respectively) compared with the I/R group that did not receive ebselen. Conversely, the 30 mg/kg dose of ebselen increased sciatic nerve damage, apoptosis, iNOS positive cells (P < 0.01, P < 0.05, P < 0.001) and MDA and NO levels (P < 0.05, P < 0.01) and decreased SOD, GPx, and CAT activities (P < 0.05) compared with the sham group. The results of this study suggest that ebselen may cause different effects depending on the dose employed. Ebselen may be protective against sciatic nerve I/R injury via antioxidant and antiapoptotic activities at a 15 mg/kg dose, conversely higher doses may cause detrimental effects. PMID:26614850

  16. N,N-diethyldithiocarbamate produces copper accumulation, lipid peroxidation, and myelin injury in rat peripheral nerve.

    PubMed

    Tonkin, Elizabeth G; Valentine, Holly L; Milatovic, Dejan M; Valentine, William M

    2004-09-01

    Previous studies have demonstrated the ability of the dithiocarbamate, disulfiram, to produce a peripheral neuropathy in humans and experimental animals and have also provided evidence that N,N-diethyldithiocarbamate (DEDC) is a proximate toxic species of disulfiram. The ability of DEDC to elevate copper levels in the brain suggests that it may also elevate levels of copper in peripheral nerve, possibly leading to oxidative stress and lipid peroxidation from redox cycling of copper. The study presented here investigates the potential of DEDC to promote copper accumulation and lipid peroxidation in peripheral nerve. Rats were administered either DEDC or deionized water by ip osmotic pumps and fed a normal diet or diet containing elevated copper, and the levels of metals, isoprostanes, and the severity of lesions in peripheral nerve and brain were assessed by ICP-AES/AAS, GC/MS, and light microscopy, respectively. Copper was the only metal that demonstrated any significant compound-related elevations relative to controls, and total copper was increased in both brain and peripheral nerve in animals administered DEDC on both diets. In contrast, lesions and elevated F2-isoprostanes were significantly increased only in peripheral nerve for the rats administered DEDC on both diets. Autometallography staining of peripheral nerve was consistent with increased metal content along the myelin sheath, but in brain, focal densities were observed, and a periportal distribution occurred in liver. These data are consistent with the peripheral nervous system being more sensitive to DEDC-mediated demyelination and demonstrate the ability of DEDC to elevate copper levels in peripheral nerve. Additionally lipid peroxidation appears to either be a contributing event in the development of demyelination, possibly through an increase of redox active copper, or a consequence of the myelin injury. PMID:15187237

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

    SciTech Connect

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

    2006-04-01

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

  18. Do Resin Cements Alter Action Potentials of Isolated Rat Sciatic Nerve?

    PubMed Central

    Ertan, Ahmet Atila; Beriat, Nilufer Celebi; Onur, Mehmet Ali; Tan, Gamze; Cehreli, Murat Cavit

    2011-01-01

    Objectives: The purpose of this study was to explore the effects dual-cure resin cements on nerve conduction. Methods: Panavia F, RelyX ARC, and Variolink II polymerized either by light-emitting diode (LED) or quartz tungsten halogen (QTH) were used in the study (n=10). The conductance of sciatic nerves of 50 rats were measured before and after contact with the specimens for 1 h. Results: The time-dependent change in nerve conductance and the comparison of LED versus QTH showed that differences between groups are significant (P<.05). For both polymerization techniques, pair-wise comparisons of resin cements showed that the nerve conductance between groups is different (P<.05). RelyX ARC elicited irreversible inhibition of compound action potentials (more than 50% change) and Panavia F and Variolink II polymerized by LED and QTH did not alter nerve conduction beyond physiologic limits. Conclusions: Resin cements may alter nerve conductance and even lead to neurotoxic effects. PMID:21494389

  19. Afferent neurons of the hypoglossal nerve of the rat as demonstrated by horseradish peroxidase tracing.

    PubMed

    Neuhuber, W; Mysicka, A

    1980-01-01

    Cell bodies of sensory neurons of the rat's hypoglossal nerve were demonstrated by the somatopetal horseradish peroxidase (HRP) transport technique. Labelled perikarya were found within the second and third cervical spinal ganglia and in the vagal sensory ganglia. After application of HRP to the cut peripheral trunk of the hypoglossal nerve about 200 labelled cell bodies were counted in each animal. The vast majority of the axons from cervical spinal ganglion cells reach the hypoglossal nerve via the descending ramus (N. descendens hypoglossi). However, there may exist an additional pathway, probably via the cervical sympathetic trunk. Application of HPR to the medial and lateral end branches led to a labelling of much fewer spinal ganglion cells while the number of labelled vegal sensory neurons remained unchanged. Thus, it is suggested that the majority of the cervical afferents of the hypoglossal nerve originates within the extrinsic tongue musculature and the geniohyoid muscle, whereas the vagal afferents may perhaps derive exclusively from the intrinsic muslces. Histograms of the mean diameters of labelled cell bodies show a predominance of very small perikarya. This contrasts with the diameter distribution of sensory perikarya labelled after HRP application to nerves supplying other skeletal muscles. It is therefore assumed that the afferent component of the hypoglossal nerve is composed mainly of small-calibre axons. PMID:7356184

  20. Effects of eugenol on nerve and vascular dysfunction in streptozotocin-diabetic rats.

    PubMed

    Nangle, Matthew R; Gibson, T Michael; Cotter, Mary A; Cameron, Norman E

    2006-05-01

    Hyperglycaemia in diabetes mellitus results in oxidative stress and pro-inflammatory changes which contribute to vascular complications including endothelial dysfunction and peripheral neuropathy. The aim of this study was to examine whether treatment with the dominant ingredient of clove oil, eugenol, which has antioxidant and anti-inflammatory properties, could improve diabetic vascular and nerve function in streptozotocin-induced diabetic rats. Intervention treatment was given for 2 weeks following 6 weeks of untreated diabetes. Dose-ranging studies on diabetic deficits in sciatic nerve motor and saphenous nerve sensory nerve conduction velocities gave ED50 values of 28 mg/kg and 9 mg/kg, respectively, conduction velocity being within the non-diabetic range at a dose of 200 mg/kg. Sciatic nerve endoneurial blood flow was 49% reduced by diabetes and this was completely corrected by 200 mg/kg eugenol treatment. Gastric fundus maximum nitrergic nerve-mediated relaxation was 44% reduced by diabetes; eugenol corrected this deficit by 69%. For renal artery rings, maximum endothelium-dependent relaxation to acetylcholine was 51% reduced by diabetes; eugenol corrected this deficit by 60%, with improvements in both nitric oxide and endothelium-derived hyperpolarising factor (EDHF)-mediated vasorelaxation components. Diabetes increased renal artery sensitivity to phenylephrine-mediated contraction, however, this was unaffected by eugenol treatment. Thus, aspects of both vascular and neural complications in experimental diabetes are improved by eugenol, which could have potential therapeutic implications for diabetic neuropathy and vasculopathy. PMID:16773532

  1. Global analysis of transcriptome in dorsal root ganglia following peripheral nerve injury in rats.

    PubMed

    Gong, Leilei; Wu, Jiancheng; Zhou, Songlin; Wang, Yaxian; Qin, Jing; Yu, Bin; Gu, Xiaosong; Yao, Chun

    2016-09-01

    Peripheral nervous system has intrinsic regeneration ability after injury, accompanied with the coordination of numerous cells, molecules and signaling pathways. These post-injury biological changes are complex with insufficient understanding. Thus, to obtain a global perspective of changes following nerve injury and to elucidate the mechanisms underlying nerve regeneration are of great importance. By RNA sequencing, we detected transcriptional changes in dorsal root ganglia (DRG) neurons at 0 h, 3 h, 9 h, 1 d, 4 d and 7 d following sciatic nerve crush injury in rats. Differentially expressed genes were then selected and classified into major clusters according to their expression patterns. Cluster 2 (with genes high expressed before 9 h and then down expressed) and cluster 6 (combination of cluster 4 and 5 with genes low expressed before 1 d and then up expressed) were underwent GO annotation and KEGG pathway analysis. Gene act networks were then constructed for these two clusters and the expression of pivotal genes was validated by quantitative real-time PCR. This study provided valuable information regarding the transcriptome changes in DRG neurons following nerve injury, identified potential genes that could be used for improving axon regeneration after nerve injury, and facilitated to elucidate the biological process and molecular mechanisms underlying peripheral nerve injury. PMID:27450809

  2. Laser-activated solder weld repair of the inferior alveolar nerve in rats

    NASA Astrophysics Data System (ADS)

    Curtis, Nigel J.; Lauto, Antonio; Trickett, Rodney I.; Owen, Earl R.; Walker, D. M.

    1997-05-01

    A new laser activated solder weld technique is described for the microsurgical repair of the inferior alveolar nerve in rats. The laser weld technique used an albumin based solder, containing indocyanine cardiogreen, plus an infrared diode laser. Seven animals had inferior alveolar nerve repairs performed using the laser weld technique and these were compared against corresponding unoperated controls plus three cases of nerve section without repair. Histochemical analysis was performed utilizing neuron counts and horseradish peroxidase tracer (HRP) uptake in the trigeminal ganglion following sacrifice and staining of frozen sections with cresyl violet and diaminobenzidene. The results of this analysis showed comparable mean neuron counts and mean HRP uptake by neurons for the unoperated control and laser weld groups with considerable reduction of mean values in cases of nerve section with no repair. Sections of the repaired inferior alveolar nerves, stained with Masson's trichrome, showed no adverse reactions by axons or epineurium to the coagulative repair with the solder and demonstrated regeneration of myelinated axons at the time of sacrifice. In summary a new technique of laser weld repair of the inferior alveolar nerve is described which, on initial analysis, appears to be a reliable alternative to traditional techniques.

  3. Influence of cervical sympathetic nerves on ventilation and upper airway resistance in the rat.

    PubMed

    O'Halloran, K D; Curran, A K; Bradford, A

    1998-07-01

    The cervical sympathetic trunks innervate the carotid bodies, carotid baroreceptors, thyroid gland and the upper airway mucosa, structures which can influence breathing and upper airway resistance. However, their role in the control of ventilation and upper airway patency is poorly understood. A constant airflow was applied to the upper airway through a high-cervical tracheostomy in anaesthetized rats breathing spontaneously through a low-cervical tracheostomy. The peripheral ends of the cut cervical sympathetic trunks were stimulated electrically and airflow resistance and ventilation were measured. The effects of cervical sympathetic trunk section on ventilation were also measured in conscious rats. In conscious rats, cutting the sympathetic trunks caused a decrease in ventilation during normoxia but only slightly affected ventilatory responses to hypoxia and hypercapnia. In anaesthetized rats, sympathetic trunk stimulation caused an inhibition of breathing which was sometimes followed by excitation. These responses were unaffected by alpha- or beta-adrenoceptor blockade but were abolished by cutting the carotid sinus nerves. Sympathetic stimulation also caused a fall in upper airway resistance which was reduced by bypassing the nose, unaffected by propranolol or carotid sinus nerve section and abolished by phentolamine. It was concluded that the cervical sympathetic nerves exert important influences on ventilation and upper airway resistance. PMID:9701434

  4. Concentration and State Dependent Reductions in Corn Oil Intakes after Glossopharyngeal Nerve Transections in Rats

    PubMed Central

    Foo, H.; Norgren, R.N.

    2014-01-01

    Previous studies indicate a role for the glossopharyngeal nerve (GL) in the detection of dietary fats. The present experiments examined the effects of bilateral glossopharyngeal nerve transections (GLx) on the intake of low (4.8%), moderate (16%), and full-fat (100%) corn oil in non-deprived, food-deprived, and water-deprived rats. The rats had access to oils, 0.3 M sucrose, and water in a gustometer that measured number of licks and latency to the first lick during brief access trials. The behavioral measures were used as indices of the amount consumed and the motivation to ingest, respectively. After baseline intakes had stabilized, the rats received GLx or sham transections (Sham), and were then re-tested. Pre and post-surgery responses were compared to determine the impact of GLx on intake and the motivation to ingest. In non-deprived rats, GLx reduced the intake of 4.8% and 16% oils and decreased the motivation to ingest these oils. In food-deprived rats, GLx prevented increases in the ingestion of 4.8% and 16% oils and in the motivation to ingest these oils. In water-deprived rats, GLx reduced the intake of 100% oil and produced a general decrease in the motivation to consume low, moderate, and full-fat emulsions. These results indicate that GL is partially involved in corn oil intake and suggest an interactive effect of oil concentration with homeostatic state. PMID:24534178

  5. Enhanced synthesis and secretion of apolipoprotein E from sciatic nerves of streptozotocin-induced diabetic rats after injury

    SciTech Connect

    Ishibashi, S.; Yamada, N.; Oka, Y.; Shimano, H.; Mori, N.; Yoon, T.H.; Shimada, M.; Kanazawa, Y.; Akanuma, Y.; Murase, T.

    1988-08-30

    To elucidate the pathogenesis of diabetic neuropathy, synthesis and secretion of apolipoprotein E (apo E) from sciatic nerves after injury was studied in normal and streptozotocin-induced diabetic rats. Seven, 14, 28, 45 and 59 days after making crush injury on sciatic nerves with concomitant administration of streptozotocin (50 mg/kg body weight), the nerves were taken out and incubated with (/sup 35/S)methionine. The (/sup 35/S)labeled apo E was precipitated with specific antiserum. The amounts of apo E secreted into medium by nerves of diabetic rats were 7 times greater than those of non-diabetic rats 7 days after injury. This enhanced secretion of apo E was relatively selective for this protein, since the ratio of the immunoprecipitable apo E to the TCA preciptitable protein in the medium increased in diabetic rats. Intriguing possibility deduced from these results is that the secretion of apo E is involved in the development of diabetic neuropathy.

  6. Changes in nerve conduction and Pi/PCr ratio during denervation-reinnervation of the gastrocsoleus muscles of rats

    NASA Technical Reports Server (NTRS)

    Lai, K. S.; Jaweed, M. M.; Seestead, R.; Herbison, G. J.; Ditunno, J. F. Jr; McCully, K.; Chance, B.

    1992-01-01

    The purpose of this investigation was to study the changes in nerve conduction and phosphate metabolites of the gastrocsoleus muscles of rats during denervation-reinnervation. Sixteen male Sprague-Dawley rats underwent unilateral crush-denervation of the left sciatic nerves at the sciatic notch. Six rats were used for measurement of motor conduction latency and action potential amplitude of the gastrocsoleus muscle by stimulating the sciatic nerve at one, two and eight weeks after nerve crush. The other ten rats were designated for evaluation of the ratio of inorganic phosphorous (Pi) to phosphocreatine (PCr) by a 31P-phosphoenergetic spectrometer at two weeks and eight weeks after nerve crush. None of the sciatic nerves showed conduction to the gastrocsoleus at one or two weeks after nerve crush. At eight weeks postcrush, the motor conduction latency returned to within normal limits, whereas the action potential amplitude was only 55% of the normal. For the eight-week period of study, the Pi/PCr ratio of the normal control muscles ranged between 0.09 +/- 0.02 and 0.11 +/- 0.02 (mean +/- SD). The denervated muscles showed an increase of Pi/PCr ratio by 54% at two weeks postcrush, compared to the respective contralateral control sides. The ratios returned to the normal value by eight weeks postcrush. In summary, these data suggested that the metabolic recovery of the crush-denervated muscle followed the same pattern as the parameters of nerve conduction.

  7. Stem cell salvage of injured peripheral nerve.

    PubMed

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

    2015-01-01

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

  8. Selectivity of distal reinnervation of regenerating mixed motor and sensory nerve fibres across muscle grafts in rats.

    PubMed

    Rath, S; Green, C J

    1991-04-01

    This study investigated target specificity during axonal regeneration of a mixed motor and sensory nerve towards respective targets. The femoral nerves in rats were divided and allowed to grow across a 6 mm gap interposed with frozen and thawed muscle grafts towards their distal motor and sensory nerve stumps. Fourteen weeks later the number of motoneurons projecting axons into the motor and sensory branches were determined by retrograde axonal tracing using horse-radish peroxidase. There were significantly higher numbers of motoneurons (p = 0.0034) projecting into the motor nerve than the sensory nerve. Efferent axons of a mixed nerve selectivity grew into motor branches when allowed to regenerate across a 6 mm gap interposed with muscle grafts. It is possible that a deliberately created 'structured gap' during repair of mixed nerves could improve axonal matching by allowing expression of neurotropism. PMID:2025759

  9. Androgen induced acceleration of functional recovery after rat sciatic nerve injury.

    PubMed

    Brown, Todd J.; Khan, Talat; Jones, Kathryn J.

    1999-01-01

    PURPOSE: Testosterone (T) treatment accelerates recovery from facial paralysis after facial nerve crush in hamsters. In this study, we extended those studies to another injury model and asked the following question: Will T treatment accelerate recovery from lower limb paralysis following sciatic nerve crush in the rat? METHODS: Castrated adult male rats received a right side sciatic nerve crush at the level of the sciatic notch, with the left side serving as control. Half the animals received a subcutaneous implant of a propionated form of T (TP), the others were sham-implanted. Weekly testing using the Sciatic Functional Index (SFI), a quantitative measure of locomotion, was done for 7 weeks postoperative (wpo). RESULTS: Between 3 and 5 weeks post-op, the average SFI score of the TP-treated group was higher than controls. This difference was significant at 4 wpo, indicating an accelerated degree of functional recovery. At these timepoints, the differences were attributable to the footprint or paw length and associated with calf muscle reinnervation rather than the toespreading component associated with intrinsic foot muscle rein-nervation. Beyond 5 wpo, there were no differences in the SFI scores. CONCLUSION: The results indicate that, as with facial nerve regeneration in the hamster, testosterone accelerates functional recovery from hind limb paralysis following sciatic nerve injury in the rat. While the responses of spinal motoneurons to injury can differ from those of cranial motoneurons, in this case it appears that they share a similar response to the trophic actions of androgen. This is important in the context of designing therapeutic strategies for dealing with direct trauma to motoneurons resulting from both peripheral and central nervous system trauma, such as spinal cord injury. PMID:12671219

  10. An inside-out vein graft filled with platelet-rich plasma for repair of a short sciatic nerve defect in rats.

    PubMed

    Kim, Ji Yeong; Jeon, Woo Joo; Kim, Dong Hwee; Rhyu, Im Joo; Kim, Young Hwan; Youn, Inchan; Park, Jong Woong

    2014-07-15

    Platelet-rich plasma containing various growth factors can promote nerve regeneration. An inside-out vein graft can substitute nerve autograft to repair short nerve defects. It is hypothesized that an inside-out vein graft filled with platelet-rich plasma shows better effects in the repair of short sciatic nerve defects. In this study, an inside-out vein autograft filled with platelet-rich plasma was used to bridge a 10 mm-long sciatic nerve defect in rats. The sciatic nerve function of rats with an inside-out vein autograft filled with platelet-rich plasma was better improved than that of rats with a simple inside-out vein autograft. At 6 and 8 weeks, the sciatic nerve function of rats with an inside-out vein autograft filled with platelet-rich plasma was better than that of rats undergoing nerve autografting. Compared with the sciatic nerve repaired with a simple inside-out vein autograft, the number of myelinated axons was higher, axon diameter and myelin sheath were greater in the sciatic nerve repaired with an inside-out vein autograft filled with platelet-rich plasma and they were similar to those in the sciatic nerve repaired with nerve autograft. These findings suggest that an inside-out vein graft filled with platelet-rich plasma can substitute nerve autograft to repair short sciatic nerve defects. PMID:25221591

  11. Chronically lowering sympathetic activity protects sympathetic nerves in spleens from aging F344 rats

    PubMed Central

    Perez, Sam D.; Kozic, Brooke; Molinaro, Christine; Thyagarajan, Srinivasan; Ghamsary, Mark; Lubahn, Cheri L.; Lorton, Dianne; Bellinger, Denise L.

    2013-01-01

    In the present study, we investigated how increased sympathetic tone during middle-age affects the splenic sympathetic neurotransmission. Fifteen-month-old F344 rats received rilmenidine (0, 0.5 or 1.5 mg/kg/day, i.p. for 90 days) to lower sympathetic tone. Controls for age were untreated 3 or 18M rats. We report that rilmenidine (1) reduced plasma and splenic norepinephrine concentrations and splenic norepinephrine turnover, and partially reversed the sympathetic nerve loss; and (2) increased β-adrenergic receptor (β-AR) density and β-AR-stimulated cAMP production. Collectively, these findings suggest a protective effect of lowering sympathetic tone on sympathetic nerve integrity, and enhanced sympathetic neurotransmission in secondary immune organs. PMID:22546498

  12. Functional and anatomical characteristics of the nerve-brown adipose interaction in the rat

    NASA Technical Reports Server (NTRS)

    Flaim, K. E.; Horowitz, J. M.; Horwitz, B. A.

    1976-01-01

    Experiments were conducted on 12 male rats to study the coupling of signals from the sympathetic nervous system to the brown adipose tissue. Analysis of electron photomicrographs revealed considerable morphological heterogeneity among the nerves entering and leaving the interscapular fat pad. In response to electrical simulation of the nerves, the temperature of the brown fat increased following a rapid but transient temperature drop. Such changes were observed only on the ipsilateral side, indicating that the innervation to the interscapular brown fat of the rat is functionally bilateral rather than diffuse. The finding that brown fat is capable of responding in a graded fashion correlates well with observations suggesting that clusters of brown adipocytes may be electrically coupled.

  13. TGF-β1 is critical for Wallerian degeneration after rat sciatic nerve injury.

    PubMed

    Li, M; Zhang, P; Li, H; Zhu, Y; Cui, S; Yao, D

    2015-01-22

    Wallerian degeneration (WD) is a process of axonal degeneration distal to the injury site followed by a robust regenerative response. It involves degeneration and regeneration which can be directly induced by nerve injury and activated by transcription factors. Although WD has been studied extensively, the precise mechanisms of transcription factors regulating WD are still elusive. In this study, we reported the effect of transforming growth factor-β1 (TGF-β1) on WD after rat sciatic nerve injury. The data showed that TGF-β1 may express in injured rat sciatic nerve and cultured Schwann cells (SCs). Knock down of TGF-β1 expressions resulted in the reduction of SC proliferation and apoptosis, up regulation of cytokines and Smad2, 4. Enhanced expression of TGF-β1 could promote SC proliferation and apoptosis, down regulation of cytokines and Smad2, 4. Altered expressions of TGF-β1 may affect Smad and AKT but not c-Jun and extracellular regulated protein kinase (ERK) pathways. Our results revealed the role of TGF-β1 on WD and provided the basis for the molecular mechanisms of TGF-β1-regulated nerve degeneration and/or regeneration. PMID:25451291

  14. Tactile stimulation during development alters the neuroanatomical organization of the optic nerve in normal rats.

    PubMed

    Horiquini-Barbosa, Everton; Lachat, João-José

    2016-06-01

    This study was designed to investigate the progressive effect of tactile stimulation in the cytoarchitecture of the optic nerve of normal rats during early postnatal development. We used 36 male pups which were randomly assigned to either the tactile-stimulated group (TS-stimulation for 3 min, once a day, from postnatal day (P) 1 to 32) or the non-tactile-stimulated (NTS) group. Morphological analysis were performed to evaluate the alterations caused by tactile stimulation, and morphometric analysis were carried out to determine whether the observed changes in optic nerve cytoarchitecture were significantly different between groups and at three different ages (P18, P22, and P32), thereby covering the entire progression of development of the optic nerve from its start to its completion. The rats of both groups presented similar increase in body weight. The morphometric analysis revealed no difference in the astrocyte density between age-matched groups; however, the oligodendrocyte density of TS group was higher compared to the NTS at P22, and P32, but not at P18. The optic nerve of TS group showed an increase of blood vessels and a reduction of damage fiber density when compared to the age-matched pups of NTS. Taken together, these findings support the view that tactile stimulation, an enriching experience, can positively affects the neuroanatomy of the brain, modifying its cellular components by progressive morphological and morphometric changes. PMID:26879768

  15. Characterization of Endoneurial Fibroblast-like Cells from Human and Rat Peripheral Nerves

    PubMed Central

    Richard, Laurence; Védrenne, Nicolas; Vallat, Jean-Michel

    2014-01-01

    Endoneurial fibroblast-like cells (EFLCs) are one of the cell populations present in the peripheral nervous system. The role and immunophenotypic characteristics of EFLCs are not well known and led us to perform a histological and cytological study of EFLCs in normal human and rat peripheral nerves. We found that all EFLCs express CD34, neural/glial antigen 2 (NG2), and prolyl-4-hydrolase-beta. In addition, half of the EFLCs in normal peripheral nerves express platelet-derived growth factor receptor-β (PDGFR-β) and some also express the intermediate filament nestin in vivo (at a lower level than Schwann cells, which express high levels of nestin). Using cell cultures of purified EFLCs, we characterized subpopulations of EFLCs expressing PDGFR-β alone or PDGFR-β and nestin. Experimental nerve lesions in rat resulted in an increase in nestin-positive EFLCs, which returned to normal levels after 8 days. This suggests that some EFLCs could have a different proliferative and/or regenerative potential than others, and these EFLCs may play a role in the initial phase of nerve repair. These “activated” EFLCs share some immunophenotypic similarities with pericytes and Interstitial cells of Cajal, which have progenitor cell potentials. This raises the questions as to whether a proportion of EFLCs have a possible role as endoneurial progenitor cells. PMID:24670794

  16. The effect of chick embryo amniotic fluid on sciatic nerve regeneration of rats

    PubMed Central

    Farjah, Gh. H.; Fazli, F.

    2015-01-01

    The purpose of this experimental study was to evaluate the effect of chicken amniotic fluid (AF) on a cross section of rat sciatic nerves. Thirty adult male Sprague-Dawley rats weighing 275 to 300 g, were randomized into three groups treated with (1) amniotic fluid or AF (n=10), (2) normal saline or NS (n=10), and (3) sham surgery (n=10). The AF was aspirated from the amniotic cavity of incubating chick embryos at day 14. The sciatic nerve was exposed and sharply transected. Immediate epineurial repair was then performed. AF treated animals were given 2 ml/kg of the chick embryo AF subcutaneously, once daily, five times a week for up to 2 weeks. All animals were evaluated by sciatic functional index (SFI), electrophysiology, histology, and immunohistochemistry at days 28 and 56 after surgery. The SFI difference between AF and NS groups at days 21 and 28 after operation was statistically significant (P<0.05). The number of myelinated fibers in the AF group was significantly greater than that of the NS group at day 28 (P<0.05). At days 28 and 56 after operation, the nerve conduction velocity (NCV) mean of the AF group was faster than that of the NS group, but the difference was not statistically significant (P>0.05). The results of this study demonstrate that chick AF can enhance peripheral nerve regeneration. PMID:27175170

  17. [Effect of stress on the development of deafferentation pain syndrome in rats after sciatic nerve transection].

    PubMed

    Osipov, A V; Kukushkin, M L

    1993-05-01

    Effect of immobilization and painful stress on the development of deafferentation pain syndrome, appeared after sciatic nerve section, has been studied in Wistar rats. It has been determined that both immobilization and painful stress favour the appearance of pain syndrome in rats without clinical signs of pain syndrome up to the moment of stress influence. There has been made a conclusion that both immobilization and painful stress favour the appearance of pathologic algic system, which is the basis of pain syndrome. The fact that stress can cause analgesia in normal animals in contrast to those with potential pain syndrome is explained to different mechanisms of physiological and pathological pain. PMID:8043822

  18. Enhanced release of adenosine in rat hind paw following spinal nerve ligation: involvement of capsaicin-sensitive sensory afferents.

    PubMed

    Liu, X J; White, T D; Sawynok, J

    2002-01-01

    Modulation of endogenous adenosine levels by inhibition of adenosine metabolism produces a peripheral antinociceptive effect in a neuropathic pain model. The present study used microdialysis to investigate the neuronal mechanisms modulating extracellular adenosine levels in the rat hind paw following tight ligation of the L5 and L6 spinal nerves. Subcutaneous injection of 50 microl saline into the nerve-injured paw induced a rapid and short-lasting increase in extracellular adenosine levels in the subcutaneous tissues of the rat hind paw ipsilateral to the nerve injury. Saline injection did not increase adenosine levels in sham-operated rats or non-treated rats. The adenosine kinase inhibitor 5'-amino-5'-deoxyadenosine and the adenosine deaminase inhibitor 2'-deoxycoformycin, at doses producing a peripheral antinociceptive effect, did not further enhance subcutaneous adenosine levels in the nerve-injured paw. Systemic pretreatment with capsaicin, a neurotoxin selective for small-diameter sensory afferents, markedly reduced the saline-evoked release of adenosine in rat hind paw following spinal nerve ligation. Systemic pretreatment with 6-hydroxydopamine, a neurotoxin selective for sympathetic afferent nerves, did not affect release. These results suggest that following nerve injury, peripheral capsaicin-sensitive primary sensory afferent nerve terminals are hypersensitive, and are able to release adenosine following a stimulus that does not normally evoke release in sham-operated or intact rats. Sympathetic postganglionic afferents do not appear to be involved in such release. The lack of effect on such release by the inhibitors of adenosine metabolism suggests an altered peripheral adenosine system following spinal nerve ligation. PMID:12204207

  19. An immunohistochemical study of the sciatic nerve in a rat knee immobilization model.

    PubMed

    Yoshida, Shinya; Matsuzaki, Taro; Hoso, Masahiro

    2016-04-01

    [Purpose] This study was performed to immunohistochemically evaluate changes in the periphery of the sciatic nerve in a rat model of knee immobilization, and to assess the effects of range of motion exercise. [Subjects and Methods] Twenty-one male rats were divided randomly into three groups: control (C), immobilized (I), and exercise (E group). Rats in the I and E groups had the right knee joint immobilized for 2 weeks. In the E group, range of motion exercise was also performed. After the experimental period, the periphery of the sciatic nerve was immunohistochemically observed. [Results] Immunohistochemical staining revealed that the myelin sheath and the perineurium in all groups were laminin positive. In the C and E groups, all rats showed normal staining. In contrast, 4 rats in the I group exhibited weak labeling. [Conclusion] Our results suggest that immobilization alters the perineurium at a molecular level and the range of motion exercise is essential for maintaining the environment of the perineurium. PMID:27190437

  20. An immunohistochemical study of the sciatic nerve in a rat knee immobilization model

    PubMed Central

    Yoshida, Shinya; Matsuzaki, Taro; Hoso, Masahiro

    2016-01-01

    [Purpose] This study was performed to immunohistochemically evaluate changes in the periphery of the sciatic nerve in a rat model of knee immobilization, and to assess the effects of range of motion exercise. [Subjects and Methods] Twenty-one male rats were divided randomly into three groups: control (C), immobilized (I), and exercise (E group). Rats in the I and E groups had the right knee joint immobilized for 2 weeks. In the E group, range of motion exercise was also performed. After the experimental period, the periphery of the sciatic nerve was immunohistochemically observed. [Results] Immunohistochemical staining revealed that the myelin sheath and the perineurium in all groups were laminin positive. In the C and E groups, all rats showed normal staining. In contrast, 4 rats in the I group exhibited weak labeling. [Conclusion] Our results suggest that immobilization alters the perineurium at a molecular level and the range of motion exercise is essential for maintaining the environment of the perineurium. PMID:27190437

  1. Saltatory conduction of peripheral nerve impulse in clioquinol-treated rats.

    PubMed

    Homma, S; Kotaki, H; Mizote, M; Nakajima, Y; Tamura, Z

    1984-04-01

    By using a new method, unidimensional latency-topography, which shows the saltatory conduction pattern of an impulse along peripheral nerve fibers, the internodal length, internodal conduction time and conduction velocity were determined from the L5 ventral and/or dorsal root filaments of clioquinol-treated rats (CTR). The saltatory conduction pattern was preserved in most of the CTR fibers tested, but was not seen in some fibers. A positive correlation was seen between the conduction velocity and the internodal length in the nerve fibers of both the normal rats and CTR. Although there was no difference in the internodal length between normal rats and CTR, conduction velocities determined in CTR fibers were lower than those in normal rat fibers. Myelin length was calculated from the saltatory conduction pattern in the topography to represent the functional length of the saltatory conduction. The functional myelin length of the CTR fiber was shorter than that of normal rats. Shortening of the functional myelin length in CTR is due to the widening of the Ranvier node, which corresponds to the exposure of the Ranvier node, i.e. demyelination. It was concluded that the decrease in conduction velocity in CTR fibers was due to exposure which caused delayed excitation at the Ranvier nodes. PMID:6233507

  2. The influence of bacterial collagenase on regeneration of severed rat sciatic nerves.

    PubMed

    Wehling, P; Pak, M; Cleveland, S; Nieper, R

    1992-01-01

    Regeneration of peripheral nerve fibers is impeded by the formation of scar tissue at the site of injury. The possible beneficial effect of collagenase on nerve regeneration was studied using clinical, neurophysiological (evoked potentials) and histological (nerve fiber counts) methods. The sciatic nerves of rats were transected and the severed ends abutted and sewn together. In one series, the area about the lesion was covered with fibrin adhesive and infused with either isotonic saline (controls) or collagenase (treatment group). In the other series, the severed ends of the nerve were inserted into a silicone tube and separated by a collagen plug, which was infused with either saline or collagenase. Compared to the controls, the treated animals showed a significant improvement of clinical and neurophysiological parameters. After 3 months of observation, the collagen content of the transection site was reduced, and in the silicone series, the total number of myelinated axons 5 mm distal to the site of transection was increased, while the fiber diameter distribution was unchanged. PMID:1336302

  3. Proteomics of the injured rat sciatic nerve reveals protein expression dynamics during regeneration.

    PubMed

    Jiménez, Connie R; Stam, Floor J; Li, Ka Wan; Gouwenberg, Yvonne; Hornshaw, Martin P; De Winter, Fred; Verhaagen, Joost; Smit, August B

    2005-02-01

    Using proteomics, we investigated the temporal expression profiles of proteins in rat sciatic nerve after experimental crush. Extracts of sciatic nerves collected at 5, 10, and 35 days after injury were analyzed by two-dimensional gel electrophoresis and quantitative image analysis. Of the approximately 1,500 protein spots resolved on each gel, 121 showed significant regulation during at least one time point. Using cluster analysis, these proteins were grouped into two expression profiles of down-regulation and four of up-regulation. These profiles mainly reflected differences in cellular origins in addition to different functional roles. Mass spectrometric analysis identified 82 proteins pertaining to several functional classes, i.e. acute-phase proteins, antioxidant proteins, and proteins involved in protein synthesis/maturation/degradation, cytoskeletal (re)organization, and in lipid metabolism. Several proteins not previously implicated in nerve regeneration were identified, e.g. translationally controlled tumor protein, annexin A9/31, vitamin D-binding protein, alpha-crystallin B, alpha-synuclein, dimethylargininases, and reticulocalbin. Real-time PCR analysis of selected genes showed which were expressed in the nerve versus the dorsal root ganglion neurons. In conclusion, this study highlights the complexity and temporal aspect of the molecular process underlying nerve regeneration and points to the importance of glial and inflammatory determinants. PMID:15509515

  4. Nicotine facilitates reinnervation of phenol-injured perivascular adrenergic nerves in the rat mesenteric resistance artery.

    PubMed

    Takatori, Shingo; Fujiwara, Hidetoshi; Hagimori, Kenta; Hashikawa-Hobara, Narumi; Yokomizo, Ayako; Takayama, Fusako; Tangsucharit, Panot; Ono, Nobufumi; Kawasaki, Hiromu

    2015-02-01

    Nicotine has been shown to have neuroprotective and neurotrophic actions in the central nervous system. To elucidate the peripheral neurotrophic effects of nicotine, we determined whether nicotine affected the reinnervation of mesenteric perivascular nerves following a topical phenol treatment. A topical phenol treatment was applied to the superior mesenteric artery proximal to the abdominal aorta in Wistar rats. We examined the immunohistochemistry of the distal small arteries 7 days after the treatment. The topical phenol treatment markedly reduced the density of tyrosine hydroxylase (TH)-LI and calcitonin gene-related peptide (CGRP)-LI fibers in these arteries. The administration of nicotine at a dose of 3 mg/kg/day (1.5 mg/kg/injection, twice a day), but not once a day or its continuous infusion using a mini-pump significantly increased the density of TH-LI nerves without affecting CGRP-LI nerves. A pretreatment with nicotinic acetylcholine receptor antagonists hexamethonium, mecamylamine, and methyllycaconitine, but not dextrometorphan, canceled the TH-LI nerve reinnervation induced by nicotine. Nicotine significantly increased NGF levels in the superior cervical ganglia (SCG) and mesenteric arteries, but not in the dorsal root ganglia, and also up-regulated the expression of NGF receptors (TrkA) in the SCG, which were canceled by hexamethonium. These results suggested that nicotine exhibited neurotrophic effects that facilitated the reinnervation of adrenergic TH-LI nerves by activating α7 nicotinic acetylcholine receptor and NGF in the SCG. PMID:25514605

  5. Recovery from rat sciatic nerve injury in vivo through the use of differentiated MDSCs in vitro

    PubMed Central

    ZENG, XIANGYI; ZHANG, LI; SUN, LIANG; ZHANG, DAI; ZHAO, HENGWU; JIA, JUN; WANG, WEI

    2013-01-01

    In this study, muscle-derived stem cells (MDSCs) whose differentiation into neuron-like cells was induced by ciliary neurotrophic factor (CNTF) and Salvia (Salvia miltiorrhiza) in vitro were used to repair rat sciatic nerve injuries in vivo, in order to investigate their multifunctional characteristics as pluripotent stem cells. The sciatic nerve in the right side of the lower limb was exposed under the anesthetized condition of 10% chloral hydrate (0.3 ml/100 g) injection into the abdominal cavity. The tissue which was 0.5 cm above the sciatic nerve bifurcation was broken using a hemostat. After induction, MDSCs were transferred in sodium hyaluronate gel and were placed into the damaged area. An untreated control group was also included in this study. The surgical area was sutured after washing with gentamycin sulfate solution. Sciatic nerve function index (SFI) was calculated, electrophysiological tests were performed and the recovery rate of gastrocnemius muscle wet weight was also calculated. Four weeks post-surgery, the SFI and the recovery rate of gastrocnemius muscle wet weight in the MDSC group were significantly higher than those in the control group (P<0.05). MDSCs whose differentiation is induced by CNTF and Salvia play an active role in the repair of peripheral nerve injury. PMID:23251266

  6. The Dilator Naris Muscle as a Reporter of Facial Nerve Regeneration in a Rat Model

    PubMed Central

    Weinberg, Julie S.; Kleiss, Ingrid J.; Knox, Christopher J.; Heaton, James T.; Hadlock, Tessa A.

    2015-01-01

    Objective Many investigators study facial nerve regeneration using the rat whisker pad model, though widely standardized outcomes measures of facial nerve regeneration in the rodent have not yet been developed. The intrinsic whisker pad “sling” muscles producing whisker protraction, situated at the base of each individual whisker, are extremely small and difficult to study en bloc. Here, we compare the functional innervation of two potential reporter muscles for whisker pad innervation: the dilator naris and the levator labii superioris, to characterize facial nerve regeneration. Methods Motor supply of the dilator naris and levator labii superioris was elucidated by measuring contraction force and compound muscle action potentials during stimulation of individual facial nerve branches, and by measuring whisking amplitude before and after dilator naris distal tendon release. Results The pattern of dilator naris innervation matched that of the intrinsic whisker pad musculature (i.e. via the buccal and marginal mandibular branches of the facial nerve), whereas the levator labii superioris appeared to be innervated almost entirely by the zygomatic branch, whose primary target is the orbicularis oculi muscle. Conclusion While the levator labii superioris has been commonly used as a reporter muscle of whisker pad innervation, the present data show that its innervation pattern does not overlap substantially with the muscles producing whisker protraction. The dilator naris muscle may serve as a more appropriate reporter for whisker pad innervation because it is innervated by the same facial nerve branches as the intrinsic whisker pad musculature, making structure\\function correlations more accurate, and more relevant to investigators studying facial nerve regeneration. PMID:25643189

  7. Preventive effect of long-term aldose reductase inhibition (ponalrestat) on nerve conduction and sural nerve structure in the spontaneously diabetic Bio-Breeding rat.

    PubMed Central

    Sima, A A; Prashar, A; Zhang, W X; Chakrabarti, S; Greene, D A

    1990-01-01

    To test the hypothesis that aldose reductase inhibition may prevent or delay the development of functional and structural neuropathy in the insulin-deficient diabetic Bio-Breeding rat (BB-rat), hyperglycemic rats were begun on the aldose reductase inhibitor (ARI) ponalrestat 25 mg/kg body wt soon after the onset of diabetes and followed for 4 or 6 mo. Ponalrestat treatment completely prevented the characteristic nerve conduction slowing and structural abnormalities of the node of Ranvier for 4 mo despite only partial preservation of axonal integrity. Ponalrestat treatment for 6 mo achieved a partial but significant prevention of nerve conduction slowing, axoglial dysjunction, and axonal degenerative changes. This incomplete but significant prevention of neuropathy by ponalrestat suggests that additional mechanisms besides polyol-pathway activation may be of importance in the pathogenesis of diabetic neuropathy. Alternatively, the dosage used in the present study may not have been sufficient to achieve a complete prevention. Despite the only partial protective effect of ARI treatment on degenerative peripheral nerve changes in hyperglycemic BB-rats, 6 mo of treatment resulted in a more than threefold increase in regenerating nerve fibers. These data suggest that prophylactic ARI treatment may be efficacious in delaying the development of diabetic neuropathy. Images PMID:2110189

  8. Functional recovery from sciatic nerve crush lesion in the rat correlates with individual differences in responses to chronic intermittent stress.

    PubMed

    van Meeteren, N L; Brakkee, J H; Helders, P J; Wiegant, V M; Gispen, W H

    1997-06-15

    The aim of the present study was to monitor the influence of chronic stress on functional recovery from a sciatic nerve crush lesion in the rat. Male Wistar rats underwent standard unilateral sciatic nerve crush. Subsequently, chronic stress was induced during the recovery phase using a daily 30 min shock box session where rats received three electric footshocks each session (0.5 sec, 1 mA). Reduced body weight gain, adrenal gland hypertrophy, and thymus involution indicated that the stress rats were chronically stressed. Evaluation of sensorimotor function revealed significant differences in recovery between control and stress groups. Correlational analysis of individual stress rats indicated that recovery of the walking pattern was negatively correlated with adrenal gland and medulla enlargement, thymus involution, and plasma levels of adrenocorticotrophic hormone (ACTH) and corticosterone 45 min following the final stress session. In control rats, the index of sciatic nerve function (SF index, expressed as the difference between the injured paw and the intact contralateral paw as a percentage) was significantly correlated with adrenal medulla weight only. The present study reveals that chronic intermittent footshock stress impedes sensorimotor recovery following a sciatic nerve crush lesion and that the consequences of chronic intermittent stress are individually determined. We suggest that the quality of functional locomotor recovery after nerve crush lesion is related to the adaptive capacity or coping style of the individual rat. PMID:9210522

  9. Gallic acid and exercise training improve motor function, nerve conduction velocity but not pain sense reflex after experimental sciatic nerve crush in male rats

    PubMed Central

    Hajimoradi, Maryam; Fazilati, Mohammad; Gharib-Naseri, Mohammad Kazem; Sarkaki, Alireza

    2015-01-01

    Objective: The aim of present study was to evaluate the effects of oral administration of gallic acid (GA) for 21 days alone and in combination with exercise on nerve conduction velocity and sensory and motor functions in rats with sciatic nerve crush. Materials and Methods: Seventy adult male Wistar rats (250-300 g) were divided randomly into 7 groups with 10 in each: 1) Control (Cont), 2) Crushed + Vehicle (Cr +Veh), 3-5) Crushed + gallic acid (Cr+GA) (50, 100, and 200 mg/kg/2 mL, orally), 6) Crushed + exercise (Cr+Exe), and 7) Crushed + exercise + effective dose of gallic acid (Cr+Exe +GA200) for 21 days. In order to establish an animal model of sciatic nerve crush, equivalent to 7 kg of force pressed on 2-3 mm of sciatic nerve for 30 s, three times with 30 s intervals. Pain sense reflex in hot plate, motor coordination in rotarod, and sciatic nerve conduction velocity (SNCV) in all groups were tested. Data were analyzed using one-way ANOVA followed by Tukey’s post hoc test and p<0.05 has assigned as the significant difference. Results: Pain threshold was increased significantly in untreated crushed rats while motor function and SNCV were decreased in all groups with nerve crush (p<0.05, p<0.01, p<0.001 vs. control). Pain reflex latency was not changed in treated groups. Motor coordination and SNCV were improved in groups Cr+GA200 and Cr+Exe + GA200 (p<0.05, p<0.01 vs. Cr+Veh). Conclusion: GA, dose-dependently, may have therapeutic potential to improve the peripheral nerve degeneration, which is most likely related, at least in part, to its antioxidant and therapeutic properties. PMID:26445710

  10. Methods to evaluate functional nerve recovery in adult rats: walking track analysis, video analysis and the withdrawal reflex.

    PubMed

    Dijkstra, J R; Meek, M F; Robinson, P H; Gramsbergen, A

    2000-03-15

    The aim of this study was to compare different methods for the evaluation of functional nerve recovery. Three groups of adult male Wistar rats were studied. In group A, a 12-mm gap between nerve ends was bridged by an autologous nerve graft; in rats of group B we performed a crush lesion of the sciatic nerve and group C consisted of non-operated control rats. The withdrawal reflex, elicited by an electric stimulus, was used to evaluate the recovery of sensory nerve function. To investigate motor nerve recovery we analyzed the walking pattern. Three different methods were used to obtain data for footprint analysis: photographic paper with thickened film developer on the paws, normal white paper with finger paint, and video recordings. The footprints were used to calculate the sciatic function index (SFI). From the video recordings, we also analyzed stepcycles. The withdrawal reflex is a convenient and reproducible test for the evaluation of global sensory nerve recovery. Recording walking movements on video and the analysis of footplacing is a perfect although time-consuming method for the evaluation of functional aspects of motor nerve recovery. PMID:10720672

  11. Efficient bridging of 20 mm rat sciatic nerve lesions with a longitudinally micro-structured collagen scaffold.

    PubMed

    Bozkurt, A; Boecker, A; Tank, J; Altinova, H; Deumens, R; Dabhi, C; Tolba, R; Weis, J; Brook, G A; Pallua, N; van Neerven, S G A

    2016-01-01

    An increasing number of biomaterial nerve guides has been developed that await direct comparative testing with the 'gold-standard' autologous nerve graft in functional repair of peripheral nerve defects. In the present study, 20 mm rat sciatic nerve defects were bridged with either a collagen-based micro-structured nerve guide (Perimaix) or an autologous nerve graft. Axons regenerated well into the Perimaix scaffold and, the majority of these axons grew across the 20 mm defect into the distal nerve segment. In fact, both the total axon number and the number of retrogradely traced somatosensory and motor neurons extending their axons across the implant was similar between Perimaix and autologous nerve graft groups. Implantation of Schwann cell-seeded Perimaix scaffolds provided only a beneficial effect on myelination within the scaffold. Functional recovery supported by the implanted, non-seeded Perimaix scaffold was as good as that observed after the autologous nerve graft, despite the presence of thinner myelin sheaths in the Perimaix implanted nerves. These findings support the potential of the Perimaix collagen scaffold as a future off-the-shelf device for clinical applications in selected cases of traumatic peripheral nerve injury. PMID:26496383

  12. Electrical Stimulation to Conductive Scaffold Promotes Axonal Regeneration and Remyelination in a Rat Model of Large Nerve Defect

    PubMed Central

    Zhang, Yongguang; Liang, Wei; Wu, Siyu; Luo, Zhuojing

    2012-01-01

    Background Electrical stimulation (ES) has been shown to promote nerve regeneration when it was applied to the proximal nerve stump. However, the possible beneficial effect of establishing a local electrical environment between a large nerve defect on nerve regeneration has not been reported in previous studies. The present study attempted to establish a local electrical environment between a large nerve defect, and examined its effect on nerve regeneration and functional recovery. Methodology/Findings In the present study, a conductive scaffold was constructed and used to bridge a 15 mm sciatic nerve defect in rats, and intermittent ES (3 V, 20 Hz) was applied to the conductive scaffold to establish an electrical environment at the site of nerve defect. Nerve regeneration and functional recovery were examined after nerve injury repair and ES. We found that axonal regeneration and remyelination of the regenerated axons were significantly enhanced by ES which was applied to conductive scaffold. In addition, both motor and sensory functional recovery was significantly improved and muscle atrophy was partially reversed by ES localized at the conductive scaffold. Further investigations showed that the expression of S-100, BDNF (brain-derived neurotrophic factor), P0 and Par-3 was significantly up-regulated by ES at the conductive scaffold. Conclusions/Significance Establishing an electrical environment with ES localized at the conductive scaffold is capable of accelerating nerve regeneration and promoting functional recovery in a 15 mm nerve defect in rats. The findings provide new directions for exploring regenerative approaches to achieve better functional recovery in the treatment of large nerve defect. PMID:22737243

  13. The Effects of Phrenic Nerve Degeneration by Axotomy and Crush on the Electrical Activities of Diaphragm Muscles of Rats.

    PubMed

    Alkiş, Mehmet Eşref; Kavak, Servet; Sayır, Fuat; Him, Aydin

    2016-03-01

    The aim of this study was to investigate the effect of axotomy and crush-related degeneration on the electrical activities of diaphragm muscle strips of experimental rats. In the present study, twenty-one male Wistar-albino rats were used and divided into three groups. The animals in the first group were not crushed or axotomized and served as controls. Phrenic nerves of the rats in the second and third groups were crushed or axotomized in the diaphragm muscle. Resting membrane potential (RMP) was decreased significantly in both crush and axotomy of diaphragm muscle strips of experimental rats (p < 0.05). Depolarization time (T DEP) and half-repolarization (1/2 RT) time were significantly prolonged in crush and axotomy rats (p < 0.05). Crushing or axotomizing the phrenic nerves may produce electrical activities in the diaphragm muscle of the rat by depolarization time and half-repolarization time prolonged in crush and axotomy rats. PMID:26972299

  14. Collateral sprouting of sensory axons after end-to-side nerve coaptation--a longitudinal study in the rat.

    PubMed

    Kovacic, Uros; Tomsic, Martin; Sketelj, Janez; Bajrović, Fajko F

    2007-02-01

    The end-to-side nerve coaptation is able to induce collateral sprouting of axons from the donor nerve and to provide functional reinnervation of the target tissue. Sensory axon sprouting and its effects on the donor nerve up to 9 months after the end-to-side nerve coaptation were studied in the rat. Peroneal, tibial and saphenous nerves were transected and ligated, and the distal stump of the transected peroneal nerve was sutured to the side of the uninjured sural nerve. The average skin area of the residual sensitivity to pinch due to the axons sprouting through the recipient peroneal nerve did not change statistically significantly between 4 and 9 months after surgery. Axon counting, measurements of compound action potentials and retrograde neuron labeling indicate that the sprouting of the myelinated sensory axons and unmyelinated axons through the recipient nerve was largely completed by 2 months and 4 months after the end-to-side nerve coaptation, respectively, and remained stable thereafter for at least 9 months. A decrease in the amplitude and area of the CAP of myelinated fibers, observed in the donor nerve up to 4 months after surgery, was probably due to mild degeneration of nerve fibers and a tendency of the diameter of myelinated axons to decline. However, no significant changes in functional, electrophysiological or morphological properties of the donor nerve could be observed at the end of the observational period, indicating that end-to-side nerve coaptation has no detrimental effect on the donor nerve on a long-term scale. PMID:17045263

  15. Neuroprotective effect of 4-(Phenylsulfanyl)butan-2-one on optic nerve crush model in rats.

    PubMed

    Chien, Jia-Ying; Sheu, Jyh-Horng; Wen, Zhi-Hong; Tsai, Rong-Kung; Huang, Shun-Ping

    2016-02-01

    This study is to investigate the effect of coral-related compound, 4-(phenylsulfanyl)butan-2-one (4-PSB-2) on optic nerves (ON) and retinal ganglion cells (RGC) in a rat model subjected to ON crush. The ONs of adult male Wistar rat (150-180 g) were crushed by a standardized method. The control eyes received a sham operation. 4-PSB-2 (5 mg/kg in 0.2 mL phosphate-buffered saline) or phosphate-buffered saline (PBS control) was immediately administered after ON crush once by subcutaneous injection. Rats were euthanized at 2 weeks after the crush injury. RGC density was counted by retrograde labeling with FluoroGold (FG) application to the superior colliculus, and visual function was assessed by flash visual evoked potentials (FVEP). TUNEL assay, immunoblotting analysis of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX2) in the retinas, and immunohistochemistry of ED1 in the ON were evaluated. Two weeks after the insult, the RGC densities in the central and mid-peripheral retinas in ON-crushed, 4-PSB-2-treated rats were significantly higher than that of the corresponding ON-crushed, PBS-treated rats FVEP measurements showed a significantly better preserved latency of the P1 wave in the ON-crushed, 4-PSB-2-treated rats than the ON-crushed, PBS treated rats. TUNEL assays showed fewer TUNEL positive cells in the ON-crushed, 4-PSB-2-treated rats. The number of ED1 positive cells was reduced at the lesion site of the optic nerve in the ON-crushed, 4-PSB-2-treated group. Furthermore, administration of 4-PSB-2 significantly attenuated ON crush insult-stimulated iNOS and COX2 expression in the retinas. These results demonstrated that 4-PSB-2 protects RGCs and helps preserve the visual function in the rat model of optic nerve crush. 4-PSB-2 may work by being anti-apoptotic and by attenuation of the inflammatory responses involving less ED1 positive cells infiltration in ON as well as suppression of iNOS/COX-2 signaling pathway in the retinas to rescue RGCs

  16. L-Ornithine intake affects sympathetic nerve outflows and reduces body weight and food intake in rats.

    PubMed

    Konishi, Yuuki; Koosaka, Yasutaka; Maruyama, Ryuutaro; Imanishi, Kazuki; Kasahara, Kazuaki; Matsuda, Ai; Akiduki, Saori; Hishida, Yukihiro; Kurata, Yasutaka; Shibamoto, Toshishige; Satomi, Jun; Tanida, Mamoru

    2015-02-01

    Ingesting the amino acid l-ornithine effectively improves lipid metabolism in humans, although it is unknown whether it affects the activities of autonomic nerves that supply the peripheral organs related to lipid metabolism, such as adipose tissues. Thus, we investigated the effects of l-ornithine ingestion on autonomic nerves that innervate adipose tissues and the feeding behaviors of rats. Intragastric injection of l-ornithine (2.5%) in urethane-anesthetized rats activated sympathetic nerve activity to white adipose tissue (WAT-SNA), and stimulated sympathetic nerve activity to brown adipose tissue (BAT-SNA). In addition, WAT-SNA responses to l-ornithine were abolished in rats with ablated abdominal vagal nerves. l-ornithine ingestion for 9 weeks also significantly reduced rats' body weight, food intake, and abdominal fat weight. Proopiomelanocortin (POMC) levels in the hypothalamus and uncoupling protein 1 (UCP1) levels in brown adipose tissue were significantly increased in rats that ingested 2.5% l-ornithine for 9 weeks. These results suggested that ingested l-ornithine was taken up in the gastrointestinal organs and stimulated afferent vagal nerves and activated the central nervous system. Subsequently, increased hypothalamic POMC activated sympathetic neurotransmission to adipose tissues and accelerated energy expenditure. PMID:25526897

  17. Leptin differentially increases sympathetic nerve activity and its baroreflex regulation in female rats: role of oestrogen.

    PubMed

    Shi, Zhigang; Brooks, Virginia L

    2015-04-01

    Obesity and hypertension are commonly associated, and activation of the sympathetic nervous system is considered to be a major contributor, at least in part due to the central actions of leptin. However, while leptin increases sympathetic nerve activity (SNA) in males, whether leptin is equally effective in females is unknown. Here, we show that intracerebroventricular (i.c.v.) leptin increases lumbar (LSNA) and renal (RSNA) SNA and baroreflex control of LSNA and RSNA in α-chloralose anaesthetized female rats, but only during pro-oestrus. In contrast, i.c.v. leptin increased basal and baroreflex control of splanchnic SNA (SSNA) and heart rate (HR) in rats in both the pro-oestrus and dioestrus states. The effects of leptin on basal LSNA, RSNA, SSNA and HR were similar in males and pro-oestrus females; however, i.c.v. leptin increased mean arterial pressure (MAP) only in males. Leptin did not alter LSNA or HR in ovariectomized rats, but its effects were normalized with 4 days of oestrogen treatment. Bilateral nanoinjection of SHU9119 into the paraventricular nucleus of the hypothalamus (PVN), to block α-melanocyte-stimulating hormone (α-MSH) type 3 and 4 receptors, decreased LSNA in leptin-treated pro-oestrus but not dioestrus rats. Unlike leptin, i.c.v. insulin infusion increased basal and baroreflex control of LSNA and HR similarly in pro-oestrus and dioestrus rats; these responses did not differ from those in male rats. We conclude that, in female rats, leptin's stimulatory effects on SNA are differentially enhanced by oestrogen, at least in part via an increase in α-MSH activity in the PVN. These data further suggest that the actions of leptin and insulin to increase the activity of various sympathetic nerves occur via different neuronal pathways or cellular mechanisms. These results may explain the poor correlation in females of SNA with adiposity, or of MAP with leptin. PMID:25398524

  18. Acetyl salicylic acid locally enhances functional recovery after sciatic nerve transection in rat.

    PubMed

    Mohammadi, Rahim; Amini, Keyvan; Abdollahi-Pirbazari, Mehdi; Yousefi, Alireza

    2013-01-01

    Local effect of acetyl salicylic acid (ASA) on peripheral nerve regeneration was studied using a rat sciatic nerve transection model. Forty-five male healthy White Wistar rats were divided into three experimental groups (n = 15), randomly: Sham-operation (SHAM), control (SIL), and ASA-treated (SIL/ASA) groups. In SHAM group after anesthesia left sciatic nerve was exposed through a gluteal muscle incision and after homeostasis the muscle was sutured. In SIL group the left sciatic nerve was exposed the same way and transected proximal to tibio-peroneal bifurcation leaving a 10-mm gap. Proximal and distal stumps were each inserted into a silicone tube and filled with 10 μl phosphate buffered solution. In SIL/ASA group defect was bridged using a silicone tube filled with 10 μl acetyl salisylic acid (0.1 mg/ml). Each group was subdivided into three subgroups of five animals each and were studied 4, 8, and 12 weeks after surgery. Data were analyzed statistically by factorial analysis of variance (ANOVA) and the Bonferroni test for pair-wise comparisons. Functional study confirmed faster and better recovery of regenerated axons in SIL/ASA than in SIL group (p < 0.05). Gastrocnemius muscle mass in SIL/ASA was significantly more than in SIL group. Morphometric indices of regenerated fibers showed that the number and diameter of the myelinated fibers in SIL/ASA were significantly higher than in control group. In immuohistochemistry, location of reactions to S-100 in SIL/ASA was clearly more positive than in SIL group. Response to local treatment of ASA demonstrates that it influences and improves functional recovery of peripheral nerve regeneration. PMID:24140781

  19. Interdependency between mechanical parameters and afferent nerve discharge in hypertrophic intestine of rats.

    PubMed

    Yang, Jian; Zhao, Jingbo; Chen, Pengmin; Nakaguchi, Toshiya; Grundy, David; Gregersen, Hans

    2016-03-15

    Partial intestinal obstruction causes smooth muscle hypertrophy, enteric neuronal plasticity, motility disorders, and biomechanical remodeling. In this study we characterized the stimulus-response function of afferent fibers innervating the partially obstructed jejunum. A key question is whether changes in afferent firing arise from remodeled mechanical tissue properties or from adaptive afferent processes. Partial obstruction was created by placing a polyethylene ring for 2 wk in jejunum of seven rats. Sham obstruction was made in six rats and seven rats served as normal controls. Firing from mesenteric afferent nerve bundles was recorded during mechanical ramp, relaxation, and creep tests. Stress-strain, spike rate increase ratio (SRIR), and firing rate in single units were assessed for evaluation of interdependency of the mechanical stimulations, histomorphometry data, and afferent nerve discharge. Partial intestinal obstruction resulted in hypertrophy and jejunal stiffening proximal to the obstruction site. Low SRIR at low strains during fast distension and at high stresses during slow distension was found in the obstructed rats. Single unit analysis showed increased proportion of mechanosensitive units but absent high-threshold (HT) units during slow stimulation, decreased number of HT units during fast stimulation, and shift from HT sensitivity towards low threshold sensitivity in the obstructed jejunum. Biomechanical remodeling and altered afferent response to mechanical stimulations were found in the obstructed jejunum. Afferents from obstructed jejunum preserved their function in encoding ongoing mechanical stimulation but showed changes in their responsiveness. The findings support that mechanical factors rather than adaption are important for afferent remodeling. PMID:26585414

  20. Behavioral side effects in rats treated with acetylcholinesterase inhibitors suggested used as prophylactics against nerve agents.

    PubMed

    Myhrer, Trond; Enger, Siri; Aas, Pål

    2010-05-01

    Acetylcholinesterase inhibitors in combination with an anticholinergic, particularly anticholinergics with antiglutamatergic properties, can effectively protect against nerve agent-induced seizures and lethality. The objective of the present study was to examine potential behavioral side effects of the anticholinesterases physostigmine (0.1mg/kg), galantamine (3mg/kg), huperzine (0.5mg/kg), and donepezil (2.5mg/kg) alone or each drug in combination with anticholinergic procyclidine (3mg/kg). The results showed that rats injected intraperitoneally with galantamine displayed a mild cognitive deficit in terms of reduced preference for novelty that was similarly found among animals treated with procyclidine combined with either galantamine or donepezil. Locomotor activity and rearing were radically depressed in all groups treated with anticholinesterases as well as in combination with procyclidine. Reductions in activity were most prominent for rats injected with galantamine alone. Equalizing effects of cholinesterase inhibitors and anticholinergics were absent in the present context. Findings from previous studies that both systemic and local (amygdala) application of physostigmine cause increased fear-motivated freezing response in rats, may explain the marked reductions in activity among the present rats. In view of these findings, use of anticholinesterases (crossing the blood-brain barrier) as prophylactics against nerve agents must be carefully examined to avoid severe side effects. PMID:20184916

  1. Early co-administration of vitamin E acetate and methylcobalamin improves thermal hyperalgesia and motor nerve conduction velocity following sciatic nerve crush injury in rats.

    PubMed

    Morani, Aashish S; Bodhankar, Subhash L

    2010-01-01

    Our previous studies have shown that early administration of vitamin E acetate (50 mg/kg, ip (VEA)) and methylcobalamin (500 microg/kg, ip (MCA)) for 30 days improved conduction velocity and neuropathic pain behavior. Here, we evaluated the effect of early co-administration of VEA and MCA (MVE) on thermal hyperlagesia (TH) and motor nerve conduction velocity (MNCV) in rats with sciatic nerve crush injury (SNCI). Fifteen days post-surgery, a reduction in paw withdrawal latency (PWL) was observed in untreated (UNTR) rats. However, latency improved in MVE-treated animals, comparable to the placebo. On day 15, a decrease in MNCV was observed in the UNTR group of animals, and this effect was not observed for the MVE and placebo groups of animals. The results of this study indicate that early exposure to MVE attenuates the progression of TH and improves MNCV in rats with SNCI. PMID:20508297

  2. Roles of estrogen and progesterone in modulating renal nerve function in the rat kidney

    PubMed Central

    Graceli, J.B.; Cicilini, M.A.; Bissoli, N.S.; Abreu, G.R.; Moysés, M.R.

    2013-01-01

    The maintenance of extracellular Na+ and Cl- concentrations in mammals depends, at least in part, on renal function. It has been shown that neural and endocrine mechanisms regulate extracellular fluid volume and transport of electrolytes along nephrons. Studies of sex hormones and renal nerves suggested that sex hormones modulate renal function, although this relationship is not well understood in the kidney. To better understand the role of these hormones on the effects that renal nerves have on Na+ and Cl- reabsorption, we studied the effects of renal denervation and oophorectomy in female rats. Oophorectomized (OVX) rats received 17β-estradiol benzoate (OVE, 2.0 mg·kg-1·day-1, sc) and progesterone (OVP, 1.7 mg·kg-1·day-1, sc). We assessed Na+ and Cl- fractional excretion (FENa+ and FECl-, respectively) and renal and plasma catecholamine release concentrations. FENa+, FECl-, water intake, urinary flow, and renal and plasma catecholamine release levels increased in OVX vs control rats. These effects were reversed by 17β-estradiol benzoate but not by progesterone. Renal denervation did not alter FENa+, FECl-, water intake, or urinary flow values vs controls. However, the renal catecholamine release level was decreased in the OVP (236.6±36.1 ng/g) and denervated rat groups (D: 102.1±15.7; ODE: 108.7±23.2; ODP: 101.1±22.1 ng/g). Furthermore, combining OVX + D (OD: 111.9±25.4) decreased renal catecholamine release levels compared to either treatment alone. OVE normalized and OVP reduced renal catecholamine release levels, and the effects on plasma catecholamine release levels were reversed by ODE and ODP replacement in OD. These data suggest that progesterone may influence catecholamine release levels by renal innervation and that there are complex interactions among renal nerves, estrogen, and progesterone in the modulation of renal function. PMID:23828583

  3. High voltage pulsed current stimulation of the sciatic nerve in rats: analysis by the SFI

    PubMed Central

    Leoni, Anita Sofia Leite; Mazzer, Nilton; Guirro, Rinaldo Roberto de Jesus; Jatte, Fernanda Guadallini; Chereguini, Paulo Augusto Costa; Monte-Raso, Vanessa Vilela

    2012-01-01

    Objective To analyze the efficiency of high voltage pulsed current (HVPC) with early application in three different sites, in the regeneration of the sciatic nerve in rats submitted to crush injury, the sciatic functional index (SFI) was used to assess the functional recovery. Methods After crushing of the nerve, 57 animals were submitted to cathodal HVPC at frequency of 50Hz and voltage of 100V, 20 minutes per day, 5 days per week. The rats were divided into five groups: control group; ganglion group; ganglion + muscle group; muscle group; and sham group. The SFI was determined weekly for seven weeks, from the preoperative period to the 6th postoperative week. Results Compared with the control group, the results showed a significantly better performance of group 2 for the first 3 weeks; group 3 showed significantly better performance in the third week; and group 4 showed a significantly negative performance during the 4th and 6th weeks. Conclusion Early application of HVPC had a positive effect in the treatment of the spinal cord region and the sciatic nerve root ganglion with a dispersive electrode on the contralateral lumbar region or on the gastrocnemius. However, HVPC had a negative effect in the treatment with an active electrode on the gastrocnemius and a dispersive electrode on the contralateral thigh. Level of evidence II, Prospective comparative study. PMID:24453588

  4. Effect of Perioperative Perineural Injection of Dexamethasone and Bupivacaine on a Rat Spared Nerve Injury Model

    PubMed Central

    Lee, Jeong Beom; Choi, Seong Soo; Ahn, Eun Hye; Hahm, Kyung Don; Suh, Jeong Hun; Leem, Jung Gil

    2010-01-01

    Background Neuropathic pain resulting from diverse causes is a chronic condition for which effective treatment is lacking. The goal of this study was to test whether dexamethasone exerts a preemptive analgesic effect with bupivacaine when injected perineurally in the spared nerve injury model. Methods Fifty rats were randomly divided into five groups. Group 1 (control) was ligated but received no drugs. Group 2 was perineurally infiltrated (tibial and common peroneal nerves) with 0.4% bupivacaine (0.2 ml) and dexamethasone (0.8 mg) 10 minutes before surgery. Group 3 was infiltrated with 0.4% bupivacaine (0.2 ml) and dexamethasone (0.8 mg) after surgery. Group 4 was infiltrated with normal saline (0.2 ml) and dexamethasone (0.8 mg) 10 minutes before surgery. Group 5 was infiltrated with only 0.4% bupivacaine (0.2 ml) before surgery. Rat paw withdrawal thresholds were measured using the von Frey hair test before surgery as a baseline measurement and on postoperative days 3, 6, 9, 12, 15, 18 and 21. Results In the group injected preoperatively with dexamethasone and bupivacaine, mechanical allodynia did not develop and mechanical threshold forces were significantly different compared with other groups, especially between postoperative days 3 and 9 (P < 0.05). Conclusions In conclusion, preoperative infiltration of both dexamethasone and bupivacaine showed a significantly better analgesic effect than did infiltration of bupivacaine or dexamethasone alone in the spared nerve injury model, especially early on after surgery. PMID:20830261

  5. Changes in the cholinergic system of rat sciatic nerve and skeletal muscle following suspension induced disuse

    NASA Technical Reports Server (NTRS)

    Gupta, R. C.; Misulis, K. E.; Dettbarn, W. D.

    1984-01-01

    Muscle disused induced changes in the cholinergic system of sciatic nerve, slow twitch soleus (SOL) and fast twitch extensor digitorum longus (EDL) muscle were studied in rats. Rats with hindlimbs suspended for 2 to 3 weeks showed marked elevation in the activity of choline acetyltransferase (ChAT) in sciatic nerve (38%), in SOL (108%) and in EDL (67%). Acetylcholinesterase (AChE) activity in SOL increased by 163% without changing the molecular forms pattern of 4S, 10S, 12S, and 16S. No significant changes in activity and molecular forms pattern of AChE were seen in EDL or in AChE activity of sciatic nerve. Nicotinic receptor binding of 3H-acetylcholine was increased in both muscles. When measured after 3 weeks of hindlimb suspension the normal distribution of type 1 fibers in SOL was reduced and a corresponding increase in type IIa and IIb fibers is seen. In EDL no significant change in fiber proportion is observed. Muscle activity, such as loadbearing, appears to have a greater controlling influence on the characteristics of the slow twitch SOL muscle than upon the fast twitch EDL muscle.

  6. Preparation of cross-linked carboxymethyl chitosan for repairing sciatic nerve injury in rats.

    PubMed

    Wang, Gan; Lu, Guangyuan; Ao, Qiang; Gong, Yandao; Zhang, Xiufang

    2010-01-01

    A successful nerve regeneration process was achieved with nerve repair tubes made up of 1-ethyl-3(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC) cross-linked carboxymethyl chitosan (CM-chitosan) with improved biodegradability. Chitosan has a very slow degradation rate, while the EDC cross-linked CM-chitosan tubes degraded to 30% of original weight during 8 weeks of incubation in lysozyme solution. In vitro cell culture indicated that the CM-chitosan films presented no cytotoxicity to Schwann cells. From in vivo studies using a 10 mm rat sciatic nerve defect model investigated by histomorphometry analysis, the average diameter of the fibers and the average thickness of myelin sheath in the CM-chitosan tubes were 3.7 +/- 0.33 and 0.33 +/- 0.04 mum, respectively, which demonstrated equivalence to nerve autografts (the current "gold" standard); furthermore, the average fiber density in the CM-chitosan tubes was 20.5 x 10(3)/mm(2), which was similar to that of autografts (21 x 10(3)/mm(2)) and significantly higher than that of common chitosan tubes (15.3 x 10(3)/mm(2)). PMID:19760120

  7. Expression pattern of myostatin in gastrocnemius muscle of rats after sciatic nerve crush injury.

    PubMed

    Liu, Mei; Zhang, Donglei; Shao, Chenxin; Liu, Jie; Ding, Fei; Gu, Xiaosong

    2007-05-01

    Myostatin is a strong inhibitor of skeletal muscle growth. The purpose of this study was to investigate myostatin expression profiles during denervation-induced muscle atrophy in order to understand the relationship between myostatin expression and muscle atrophy. We constructed a sciatic nerve crush model, undertook morphometric analyses of rat gastrocnemius muscle to evaluate the degree of muscle atrophy, and utilized a real-time quantitative reverse transcription-polymerase chain reaction (RT-PCR) and Western blot analysis to measure myostatin mRNA and protein expression levels, respectively, in the gastrocnemius at different time-points after nerve injury. Muscle atrophy changed in a parabola-like manner from day 1 to day 28 after nerve injury, with a maximum value at day 14. During this time, myostatin expression changed in the reverse manner, with myostatin mRNA or protein expression gradually increasing from days 1-14, and then gradually declining to day 28, when the normal level was reached. Statistical analyses further provided evidence for a significant negative linear correlation between myostatin expression and muscle atrophy within a 28-day period after nerve injury. Our study thus describes the expression pattern of myostatin in response to a specific type of muscle atrophy and raises the possibility of developing myostatin as a therapeutic target for future clinical applications. PMID:17326119

  8. Metanx alleviates multiple manifestations of peripheral neuropathy and increases intraepidermal nerve fiber density in Zucker diabetic fatty rats.

    PubMed

    Shevalye, Hanna; Watcho, Pierre; Stavniichuk, Roman; Dyukova, Elena; Lupachyk, Sergey; Obrosova, Irina G

    2012-08-01

    Metanx is a product containing L-methylfolate, pyridoxal 5'-phosphate, and methylcobalamin for management of endothelial dysfunction. Metanx ingredients counteract endothelial nitric oxide synthase uncoupling and oxidative stress in vascular endothelium and peripheral nerve. This study evaluates Metanx on diabetic peripheral neuropathy in ZDF rats, a model of type 2 diabetes. Metanx was administered to 15-week-old ZDF and ZDF lean rats at either 4.87 mg ⋅ kg(-1) ⋅ day(-1) (a body weight-based equivalent of human dose) or 24.35 mg ⋅ kg(-1) ⋅ day(-1) by oral gavage two times a day for 4 weeks. Both doses alleviated hind limb digital sensory, but not sciatic motor, nerve conduction slowing and thermal and mechanical hypoalgesia in the absence of any reduction of hyperglycemia. Low-dose Metanx increased intraepidermal nerve fiber density but did not prevent morphometric changes in distal tibial nerve myelinated fibers. Metanx treatment counteracted endothelial nitric oxide synthase uncoupling, inducible nitric oxide synthase upregulation, and methylglyoxal-derived advanced glycation end product, nitrotyrosine, and nitrite/nitrate accumulation in the peripheral nerve. In conclusion, Metanx, at a body weight-based equivalent of human dose, increased intraepidermal nerve fiber density and improved multiple parameters of peripheral nerve function in ZDF rats. Clinical studies are needed to determine if Metanx finds use in management of diabetic peripheral neuropathy. PMID:22751692

  9. Identification of binding sites for an insulin-like growth factor (IGF-I) in the median eminence of the rat brain by quantitative autoradiography

    SciTech Connect

    Bohannon, N.J.; Figlewicz, D.P.; Corp, E.S.; Wilcox, B.J.; Porte, D. Jr.; Baskin, D.G.

    1986-08-01

    The microanatomical location of IGF-I binding in the rat brain was determined by in vitro autoradiography with slide-mounted sections of frozen brain. Sections incubated in 0.1 nM (/sup 125/I)-iodo-IGF-I produced a dense grain concentration in regions of the autoradiographic image corresponding to the external palisade zone of the median eminence; other hypothalamic regions were not so heavily labeled. This reaction was significantly reduced in the presence of 100 nM IGF-I. Measurement of binding by computer digital image analysis of autoradiographic images showed that specific binding for IGF-I in the median eminence was 41.3 +/- 8 X 10(-3) fmol/mm2 (mean +/- SEM); nonspecific binding was 11.9 +/- 1.8 X 10(-3) fmol/mm2. In contrast, specific binding to other hypothalamic regions was uniformly lower. In a separate experiment, 1000 nM unlabeled insulin was added. Without insulin, specific binding was 23 +/- 0.9 X 10(-3) fmol/mm2; nonspecific binding was 8 +/- 0.5 X 10(-3) fmol/mm2. In the presence of 1000 nM unlabeled insulin, specific binding for (/sup 125/I)-iodo-IGF-I was 23 +/- 1 X 10(-3) fmol/mm2. The results suggest that a high concentration of receptors for an IGF-I-like molecule is present in the median eminence.

  10. A System for Delivering Mechanical Stimulation and Robot-Assisted Therapy to the Rat Whisker Pad during Facial Nerve Regeneration

    PubMed Central

    Heaton, James T.; Knox, Christopher; Malo, Juan; Kobler, James B.; Hadlock, Tessa A.

    2013-01-01

    Functional recovery is typically poor after facial nerve transection and surgical repair. In rats, whisking amplitude remains greatly diminished after facial nerve regeneration, but can recover more completely if the whiskers are periodically mechanically stimulated during recovery. Here we present a robotic “whisk assist” system for mechanically driving whisker movement after facial nerve injury. Movement patterns were either pre-programmed to reflect natural amplitudes and frequencies, or movements of the contralateral (healthy) side of the face were detected and used to control real-time mirror-like motion on the denervated side. In a pilot study, twenty rats were divided into nine groups and administered one of eight different whisk assist driving patterns (or control) for 5–20 minutes, five days per week, across eight weeks of recovery after unilateral facial nerve cut and suture repair. All rats tolerated the mechanical stimulation well. Seven of the eight treatment groups recovered average whisking amplitudes that exceeded controls, although small group sizes precluded statistical confirmation of group differences. The potential to substantially improve facial nerve recovery through mechanical stimulation has important clinical implications, and we have developed a system to control the pattern and dose of stimulation in the rat facial nerve model. PMID:23475376

  11. Nerve growth factor preserves a critical motor period in rat striatum.

    PubMed

    Wolansky, M J; Paratcha, G C; Ibarra, G R; Azcurra, J M

    1999-01-01

    We previously found the occurrence of a critical motor period during rat postnatal development where circling training starting the 7-day schedule at 30 days-but not before or after-induces a lifetime drop in the binding to cholinergic muscarinic receptors (mAChRs) in striatum. Here, we studied whether nerve growth factor (NGF) participates in this restricted period of muscarinic sensitivity. For this purpose, we administered mouse salival gland 2.5S NGF (1.4 or 0.4 microg/day, infused by means of ALZA minipumps) by intrastriatal unilateral route between days 25 and 39, and then trained rats starting at 40 days. Under these conditions, NGF induced a long-term reduction in the striatal [3H] quinuclidilbenzylate (QNB) binding sites despite the fact that motor training was carried out beyond the natural critical period. Thus, at day 70, measurement of specific QNB binding in infused striata of trained rats showed decreases of 42% (p < .0004) and 33% (p < .02) after administration of the higher and lower NGF doses, respectively, with respect to trained rats treated with cytochrome C, for control. Noncannulated striata of the NGF-treated rats also showed a decrease in QNB binding sites (44%; p < .0001) only at the higher infusion rate. This effect was not found in the respective control groups. Our observations show that NGF modulates the critical period in which activity-dependent mAChR setting takes place during rat striatal maturation. PMID:10027568

  12. Short-term vagal nerve stimulation improves left ventricular function following chronic heart failure in rats

    PubMed Central

    LI, YAN; XUAN, YAN-HUA; LIU, SHUANG-SHUANG; DONG, JING; LUO, JIA-YING; SUN, ZHI-JUN

    2015-01-01

    Increasing numbers of animal and clinical investigations have demonstrated the effectiveness of long-term electrical vagal nerve stimulation (VNS) on chronic heart failure (CHF). The present study investigated the effects of short-term VNS on the hemodynamics of cardiac remodeling and cardiac excitation-contraction coupling (ECP) in an animal model of CHF following a large myocardial infarction. At 3 weeks subsequent to ligation of the left coronary artery, the surviving rats were randomized into vagal and sham-stimulated groups. The right vagal nerve of the CHF rats was stimulated for 72 h. The vagal nerve was stimulated with rectangular pulses of 40 ms duration at 1 Hz, 5 V. The treated rats, compared with the untreated rats, had significantly higher left ventricular ejection fraction (54.86±9.73, vs. 45.60±5.51%; P=0.025) and left ventricular fractional shortening (25.31±6.30, vs. 15.42±8.49%; P=0.013), and lower levels of brain natriuretic peptide (10.07±2.63, vs. 19.95±5.22 ng/ml; P=0.001). The improvement in cardiac pumping function was accompanied by a decrease in left ventricular end diastolic volume (1.11±0.50, vs. 1.54±0.57 cm3; P=0.032) and left ventricular end systolic volume (0.50±0.28, vs. 0.87±0.36 cm3; P=0.007). Furthermore, the expression levels of ryanodine receptor type 2 (RyR2) and sarcoplasmic reticulum calcium adenosine triphosphatase (SERCA2) were significantly higher in the treated rats compared with the untreated rats (P=0.011 and P=0.001 for RyR2 and SERCA2, respectively). Therefore, VNS was beneficial to the CHF rats through the prevention of cardiac remodeling and improvement of cardiac ECP. PMID:25873055

  13. Crucifixion and median neuropathy

    PubMed Central

    Regan, Jacqueline M; Shahlaie, Kiarash; Watson, Joseph C

    2013-01-01

    Crucifixion as a means of torture and execution was first developed in the 6th century B.C. and remained popular for over 1000 years. Details of the practice, which claimed hundreds of thousands of lives, have intrigued scholars as historical records and archaeological findings from the era are limited. As a result, various aspects of crucifixion, including the type of crosses used, methods of securing victims to crosses, the length of time victims survived on the cross, and the exact mechanisms of death, remain topics of debate. One aspect of crucifixion not previously explored in detail is the characteristic hand posture often depicted in artistic renditions of crucifixion. In this posture, the hand is clenched in a peculiar and characteristic fashion: there is complete failure of flexion of the thumb and index finger with partial failure of flexion of the middle finger. Such a “crucified clench” is depicted across different cultures and from different eras. A review of crucifixion history and techniques, median nerve anatomy and function, and the historical artistic depiction of crucifixion was performed to support the hypothesis that the “crucified clench” results from proximal median neuropathy due to positioning on the cross, rather than from direct trauma of impalement of the hand or wrist. PMID:23785656

  14. PGC-1α Mediated Peripheral Nerve Protection of Tongxinluo in STZ-Induced Diabetic Rats

    PubMed Central

    Cui, Xiaopei; Feng, Hua; Xu, Xia; Li, Haijun

    2016-01-01

    Aim. To investigate the effect of Tongxinluo (Txl), a Chinese herbal compound, on diabetic peripheral neuropathy (DPN). Methods and Results. Diabetic rat model was established by peritoneal injection of streptozotocin (STZ). Txl ultrafine powder treatment for 16 weeks from the baseline significantly reversed the impairment of motor nerve conductive velocity (MNCV), mechanical hyperalgesia, and nerve structure. We further proved that Tongxinluo upregulates PGC-1α and its downstream factors including COX IV and SOD, which were involved in mitochondrial biogenesis. Conclusion. Our study indicates that the protective effect of Txl in diabetic neuropathy may be attributed to the induction of PGC-1α and its downstream targets. This finding may further illustrate the pleiotropic effect of the medicine. PMID:27504136

  15. [Histotopography and composition of the microcirculatory bed of the sciatic nerve in the rat].

    PubMed

    Gasymov, E K

    1989-11-01

    By means of macro-microscopical preparation methods, horseradish peroxidase injection, semithin sections, electron microscopy histotopography and composition of microvessels of the sciatic nerve have been studied in 20 mature male white rats. The perineural membrane has been stated to have no its own vascular network. In composition of the sciatic nerve and its large branches muscular venules are revealed; they run longitudinally along the whole length of the endoneural space and are tributaries of the epineural veins. A suggestion is made that presence of the contractile apparatus in the venular wall can play an important role in formation of the postcapillary resistance, regulating the hydrostatic pressure value in the lumen of endoneural capillaries ad intensity of liquor filtration into the interstitial space. PMID:2483607

  16. Berberine Ameliorates Allodynia Induced by Chronic Constriction Injury of the Sciatic Nerve in Rats.

    PubMed

    Kim, Hyun Jee

    2015-08-01

    The objective of this study was to investigate whether berberine could ameliorate allodynia induced by chronic constriction injury (CCI) of the sciatic nerve in rats. After inducement of CCI, significant increases in the number of paw lifts from a cold plate test (cold allodynia) and decreased paw withdrawal threshold in the von Frey hair stimulation test (mechanical allodynia) were observed. However, these cold and mechanical allodynia were markedly alleviated by berberine administration in a dose-dependent manner. Sciatic nerve myeloperoxidase and malondialdehyde activities were also attenuated by berberine administration. Continuous injection for 7 days induced no development of tolerance. The antiallodynic effect of 20 mg/kg berberine was comparable to that of amitriptyline 10 mg/kg. This study demonstrated that berberine could mitigate allodynia induced by CCI, a neuropathic pain model, and it suggested that the anti-inflammatory and antioxidative properties of berberine contributed to the antiallodynic effect in the CCI model. PMID:25674823

  17. Isolated median sensory neuropathy after acupuncture.

    PubMed

    Lee, Chang Ho; Hyun, Jung Keun; Lee, Seong Jae

    2008-12-01

    A 47-year-old left-handed man presented with pain and numbness in his left thumb and index finger after acupuncture treatment on an acupoint in his left wrist. A technique of herbal acupuncture, involving the use of a needle coated with apricot seed extract, was used. Median nerve conduction study showed an absence of sensory nerve action potential in the left index finger, whereas the results were normal in all other fingers. The radial and ulnar nerves in the left thumb and ring finger, respectively, showed no abnormality. Infrared thermography of the left index finger showed severe hypothermia. The patient was diagnosed as having an isolated injury to the sensory nerve fibers of the median nerve innervating the index finger. This is the first case report of complications from an herbal acupuncture treatment, and it highlights the possibility of focal peripheral nerve injury caused by acupuncture. PMID:19061751

  18. Increase of transcription factor EB (TFEB) and lysosomes in rat DRG neurons and their transportation to the central nerve terminal in dorsal horn after nerve injury.

    PubMed

    Jung, J; Uesugi, N; Jeong, N Y; Park, B S; Konishi, H; Kiyama, H

    2016-01-28

    In the spinal dorsal horn (DH), nerve injury activates microglia and induces neuropathic pain. Several studies clarified an involvement of adenosine triphosphate (ATP) in the microglial activation. However, the origin of ATP together with the release mechanism is unclear. Recent in vitro study revealed that an ATP marker, quinacrine, in lysosomes was released from neurite terminal of dorsal root ganglion (DRG) neurons to extracellular space via lysosomal exocytosis. Here, we demonstrate a possibility that the lysosomal ingredient including ATP released from DRG neurons by lysosomal-exocytosis is an additional source of the glial activation in DH after nerve injury. After rat L5 spinal nerve ligation (SNL), mRNA for transcription factor EB (TFEB), a transcription factor controlling lysosomal activation and exocytosis, was induced in the DRG. Simultaneously both lysosomal protein, LAMP1- and vesicular nuclear transporter (VNUT)-positive vesicles were increased in L5 DRG neurons and ipsilateral DH. The quinacrine staining in DH was increased and co-localized with LAMP1 immunoreactivity after nerve injury. In DH, LAMP1-positive vesicles were also co-localized with a peripheral nerve marker, Isolectin B4 (IB4) lectin. Injection of the adenovirus encoding mCherry-LAMP1 into DRG showed that mCherry-positive lysosomes are transported to the central nerve terminal in DH. These findings suggest that activation of lysosome synthesis including ATP packaging in DRG, the central transportation of the lysosome, and subsequent its exocytosis from the central nerve terminal of DRG neurons in response to nerve injury could be a partial mechanism for activation of microglia in DH. This lysosome-mediated microglia activation mechanism may provide another clue to control nociception and pain. PMID:26601776

  19. The effects of gradients of nerve growth factor immobilized PCLA scaffolds on neurite outgrowth in vitro and peripheral nerve regeneration in rats.

    PubMed

    Tang, Shuo; Zhu, Jixiang; Xu, Yangbin; Xiang, Andy Peng; Jiang, Mei Hua; Quan, Daping

    2013-09-01

    Introducing concentration gradients of nerve growth factor (NGF) into conduits for repairing of peripheral nerve injury is crucial for nerve regeneration and guidance. Herein, combining differential adsorption of NGF/silk fibroin (SF) coating, the gradient of NGF-immobilized membranes (G-Ms) and nanofibrous nerve conduits (G-nNCs) were successfully fabricated. The efficacy of NGF gradients was confirmed by a quantitative comparison of dorsal root ganglia (DRG) neurite outgrowth on the G-Ms or uniform NGF-immobilized membranes (U-Ms). Significantly, the neurite turning ratio was 0.48 ± 0.11 for G-M group, but it was close to zero for U-M group. The neurite length of DRGs in the middle of the G-Ms was significantly longer than that of U-M group, even though the average NGF concentration was approximated. Furthermore, 12 weeks after implantation in rats with a 14 mm gap of sciatic nerve injury, G-nNCs achieved satisfying outcomes of nerve regeneration associated with morphological and functional improvements, which was superior to that of the uniform NGF-immobilized nNCs (U-nNCs). Sciatic function index (SFI), compound muscle action potentials (CMAPs), total number of myelinated nerve fibers, thickness of myelin sheath were similar for the G-nNCs and autografts, with the G-nNCs having a higher density of axons than the autografts. Our results demonstrated the significant role of introducing NGF gradients into scaffolds in promoting nerve regeneration. PMID:23791502

  20. Protective effects of cerebrolysin in a rat model of optic nerve crush.

    PubMed

    Huang, Tzu-Lun; Huang, Sun-Ping; Chang, Chung-Hsing; Lin, Kung-Hung; Sheu, Min-Muh; Tsai, Rong-Kung

    2014-07-01

    To investigate the effects of cerebrolysin (Cbl) on optic nerves (ON) and retinal ganglion cells (RGC) in a rat model of ON crush. Rats received intravitreal injection of Cbl (n = 20), intra-ON injection of Cbl (n = 20), intraperitoneal injection (IPI) of Cbl (n = 20), or phosphate buffered saline (PBS; n = 20) every day for 2 weeks after ON crush injury. At 3 weeks post-trauma, RGC density was counted by retrograde labeling with FluoroGold and visual function was assessed by flash visual-evoked potentials. Activities of microglia after insults were quantified by immunohistochemical analysis of the presence of ED1 in the optic nerve. At 3 weeks postcrush, the densities of RGCs in the Cbl-IVI group (1125 ± 166/mm(2)) and in the Cbl-IPI treatment group (1328 ± 119/mm(2)) were significantly higher than those in the PBS group (641 ± 214/mm(2)). The flash visual-evoked potential measurements showed that latency of the P1 wave was significantly shorter in the Cbl-IVI- and Cbl-IPI-treated groups (105 ± 4 ms and 118 ± 26 ms, respectively) than in the PBS-treated group (170 ± 20 ms). However, only Cbl IPI treatment resulted in a significant decrease in the number of ED1-positive cells at the lesion sites of the ON (5 ± 2 cells/vs. 30 ± 4 cells/high-power field in control eyes). Treatment with intra-ON injection of Cbl was harmful to the optic nerve in the crush model. Systemic administration of Cbl had neuroprotective effects on RGC survival and visual function in the optic nerve crush model. PMID:24924838

  1. Histopathological nerve and skeletal muscle changes in rats subjected to persistent insulin-induced hypoglycemia

    PubMed Central

    Jensen, Vivi Flou Hjorth; Mølck, Anne-Marie; Heydenreich, Annette; Jensen, Karin Juul; Bertelsen, Line Olrik; Alifrangis, Lene; Andersen, Lene; Søeborg, Henrik; Chapman, Melissa; Lykkesfeldt, Jens; Bøgh, Ingrid Brück

    2015-01-01

    New insulin analogues with a longer duration of action and a flatter pharmacodynamic profile are developed to improve convenience and safety for diabetic patients. During the nonclinical development of such analogues, safety studies must be conducted in nondiabetic rats, which consequently are rendered chronically hypoglycemic. A rat comparator model using human insulin would be valuable, as it would enable differentiation between effects related to either persistent insulin-induced hypoglycemia (IIH) or a new analogue per se. Such a model could alleviate the need for an in-study-comparator and thereby reduce the number of animals used during development. Thus, the aims of the present study were i) to develop a preclinical animal model of persistent hypoglycemia in rats using human insulin infusion for four weeks and ii) to investigate histopathological changes in sciatic nerves and quadriceps femoris muscle tissue, as little is known about the response to persistent hypoglycemia in these tissues. Histopathologic changes in insulin-infused animals included axonal degeneration and myofibre degeneration. To our knowledge, this is the first study to show that persistent IIH provokes peripheral nerve and skeletal myofiber degeneration within the same animals. This suggests that the model can serve as a nonclinical comparator model during development of long-acting insulin analogues. PMID:26989298

  2. Effects of pulsed electromagnetic field and swimming exercise on rats with experimental sciatic nerve injury.

    PubMed

    Kavlak, Erdoğan; Belge, Ferda; Unsal, Cengiz; Uner, Aykut Göktürk; Cavlak, Uğur; Cömlekçi, Selçuk

    2014-09-01

    [Purpose] The current study aimed to reveal the therapeutic effects of a pulsed electromagnetic field and swimming exercises on rats with experimental sciatic nerve injury, which was induced with crush-type neuropathy model damage, using electrophysiological methods. [Subjects] In the current study, the sample consisted of 28 adult male Wistar albino rats. [Methods] The rats were randomized into four groups (n=7). Swimming exercise and PEMF (2 Hz and 0.3 MT) were applied one hour a day, five days a week, for four weeks. Electroneuromyographic (ENMG) measurements were taken on day 7. [Results] When the data were evaluated, it was found that the 4 weeks of PEMF and swimming exercises led to an increase in motor conduction rates and a decrease in latency values, but the changes were not significant in comparison with the control and injury groups. The compound muscle action potential (CMAP) values of the left leg were lower in weeks 2, 3, and 4 in the swimming exercise group in comparison with the control group, although for the PEMF group, the CMAP values of the left leg reached the level observed in the control group beginning in week 3. [Conclusion] PEMF and swimming exercise made positive contributions to nerve regeneration after week 1, and regeneration was enhanced. PMID:25276015

  3. Effects of Pulsed Electromagnetic Field and Swimming Exercise on Rats with Experimental Sciatic Nerve Injury

    PubMed Central

    Kavlak, Erdoğan; Belge, Ferda; Ünsal, Cengiz; Üner, Aykut Göktürk; Cavlak, Uğur; Çömlekçi, Selçuk

    2014-01-01

    [Purpose] The current study aimed to reveal the therapeutic effects of a pulsed electromagnetic field and swimming exercises on rats with experimental sciatic nerve injury, which was induced with crush-type neuropathy model damage, using electrophysiological methods. [Subjects] In the current study, the sample consisted of 28 adult male Wistar albino rats. [Methods] The rats were randomized into four groups (n=7). Swimming exercise and PEMF (2 Hz and 0.3 MT) were applied one hour a day, five days a week, for four weeks. Electroneuromyographic (ENMG) measurements were taken on day 7. [Results] When the data were evaluated, it was found that the 4 weeks of PEMF and swimming exercises led to an increase in motor conduction rates and a decrease in latency values, but the changes were not significant in comparison with the control and injury groups. The compound muscle action potential (CMAP) values of the left leg were lower in weeks 2, 3, and 4 in the swimming exercise group in comparison with the control group, although for the PEMF group, the CMAP values of the left leg reached the level observed in the control group beginning in week 3. [Conclusion] PEMF and swimming exercise made positive contributions to nerve regeneration after week 1, and regeneration was enhanced. PMID:25276015

  4. Attenuated baroreflex control of sympathetic nerve activity after cardiovascular deconditioning in rats

    NASA Technical Reports Server (NTRS)

    Moffitt, J. A.; Foley, C. M.; Schadt, J. C.; Laughlin, M. H.; Hasser, E. M.

    1998-01-01

    The effect of cardiovascular deconditioning on baroreflex control of the sympathetic nervous system was evaluated after 14 days of hindlimb unloading (HU) or the control condition. Rats were chronically instrumented with catheters and sympathetic nerve recording electrodes for measurement of mean arterial pressure (MAP) and heart rate (HR) and recording of lumbar (LSNA) or renal (RSNA) sympathetic nerve activity. Experiments were conducted 24 h after surgery, with the animals in a normal posture. Baroreflex function was assessed using a logistic function that related HR and LSNA or RSNA to MAP during infusion of phenylephrine and nitroprusside. Baroreflex influence on HR was not affected by HU. Maximum baroreflex-elicited LSNA was significantly reduced in HU rats (204 +/- 11.9 vs. 342 +/- 30.6% baseline LSNA), as was maximum reflex gain (-4.0 +/- 0.6 vs. -7.8 +/- 1.3 %LSNA/mmHg). Maximum baroreflex-elicited RSNA (259 +/- 10.8 vs. 453 +/- 28.0% baseline RSNA), minimum baroreflex-elicited RSNA (-2 +/- 2.8 vs. 13 +/- 4.5% baseline RSNA), and maximum gain (-5.8 +/- 0.5 vs. -13.6 +/- 3.1 %RSNA/mmHg) were significantly decreased in HU rats. Results demonstrate that baroreflex modulation of sympathetic nervous system activity is attenuated after cardiovascular deconditioning in rodents. Data suggest that alterations in the arterial baroreflex may contribute to orthostatic intolerance after a period of bedrest or spaceflight in humans.

  5. Chemical Topography of Efferent Projections from the Median Preoptic Nucleus to Pontine Monoaminergic Cell Groups in the Rat

    NASA Technical Reports Server (NTRS)

    Zardetto-Smith, Andrea M.; Johnson, Alan Kim

    1995-01-01

    This study examined efferent output from the median preoptic nucleus (MNPO) to pontine noradrenergic and serotonergic cell groups using an anterograde tracing technique (Phaseolus vulgaris leucoagglutinin, PHA-L) combined with glucose oxidase immunocytochemistry to serotonin (5-HT) or to dopamine-beta-hydroxylase (DBH). Injections of PHA-L into the ventral MNPO resulted in moderate axonal labeling within the region of the B7 and B8 serotonergic groups in the dorsal raphe. PHA-L labeled fibers and punctate processes were observed in close apposition to many of the 5-HT immunoreactive neurons in these regions. In contrast, sparse terminal labeling was found within the B5 group in the raphe pontis nucleus, and only trace fiber labeling observed in the B3 and B6 groups. Efferents from the MNPO also provided moderate innervation to the A6 and A7 noradrenergic groups. PHA-L labeled punctate processes were found most frequently in close apposition to DBH-immunoreactive neurons at mid- to caudal levels of the locus coeruleus. Some labeled axons were also present within the A7 and A5 groups. Additionally, a close apposition between labeled MNPO efferents and 5-HT fibers within the lateral parabrachial nucleus was observed. The results indicate the MNPO provides a topographic innervation of monoaminergic groups in the upper brainstem.

  6. Chemical Topography of Efferent Projections from the Median Preoptic Nucleus to Pontine Monoaminergic Cell Groups in the Rat

    NASA Technical Reports Server (NTRS)

    Zardetto-Smith, Andrea M.; Johnson, Alan Kim

    1995-01-01

    This study examined efferent output from the median preoptic nucleus (MnPO) to pontine noradrenergic and serotonergic cell groups using an anterograde tracing technique (Phaseolus vulgaris leucoagglutinin, PHA-L) combined with glucose oxidase immunocytochemistry to scrotonin (5-HT) or to dopamine-(beta)-hydroxylase (DBH). Injections of PHA-L into the ventral MNPO resulted in moderate axonal labeling within the region of the B7 and B8 serotonergic groups in the dorsal raphe. PHA-L labeled fibers and punctate processes were observed in close apposition to many of the 5-HT immunoreactive neurons in these regions, In contrast, sparse terminal labeling was found within the B5 group in the raphe pontis nucleus, and only trace fiber labeling observed in the B3 and B6 groups. Efferents from the MNPO also provided moderate innervation to the A6 and A7 noradrenergic groups. PHA-L labeled punctate processes were found most frequently in close apposition to DBH-immunorcactive neurons at mid- to caudal levels of the locus coeruleus. Some labeled axons were also present within the A7 and A5 groups. Additionally, a close apposition between labeled MNPO efferents and 5-HT fibers within the lateral parabrachial nucleus was observed, The results indicate the MNPO provides a topographic innerva- tion of monoaminergic groups in the upper brainstem.

  7. Long-term effect of ropivacaine nanoparticles for sciatic nerve block on postoperative pain in rats

    PubMed Central

    Wang, Zi; Huang, Haizhen; Yang, Shaozhong; Huang, Shanshan; Guo, Jingxuan; Tang, Qi; Qi, Feng

    2016-01-01

    Purpose The analgesic effect of ropivacaine (Rop) for nerve block lasts only ~3–6 hours for single use. The aim of this study was to develop long-acting regional anesthetic Rop nanoparticles and investigate the effects of sciatic nerve block on postoperative pain in rats. Materials and methods Rop nanoparticles were developed using polyethylene glycol-co-polylactic acid (PELA). One hundred and twenty adult male Wistar rats were randomly divided into four groups (n=30, each): Con (control group; 0.9% saline, 200 µL), PELA (PELA group; 10 mg), Rop (Rop group; 0.5%, 200 µL), and Rop-PELA (Rop-PELA group; 10%, 10 mg). Another 12 rats were used for the detection of Rop concentration in plasma. The mechanical withdrawal threshold and thermal withdrawal latency were measured at 2 hours, 4 hours, 8 hours, 1 day, 2 days, 3 days, 5 days, and 7 days after incision. The expression of c-FOS was determined by immunohistochemistry at 2 hours, 8 hours, 48 hours, and 7 days. Nerve and organ toxicities were also evaluated at 7 days. Results The duration of Rop absorption in the plasma of the Rop-PELA group was longer (>8 hours) than that of the Rop group (4 hours). Mechanical withdrawal threshold and thermal withdrawal latency in the Rop-PELA group were higher than that in other groups (4 hours–3 days). c-FOS expression in the Rop-PELA group was lower than that in the control group at 2 hours, 8 hours, and 48 hours and lower than that in the Rop group at 8 hours and 48 hours after paw incision. Slight foreign body reactions were observed surrounding the sciatic nerve at 7 days. No obvious pathophysiological change was found in the major organs after Rop-PELA administration at 7 days. Conclusion Rop-PELA provides an effective analgesia for nerve block over 3 days after single administration, and the analgesic mechanism might be mediated by the regulation of spinal c-FOS expression. However, its potential long-term tissue toxicity needs to be further investigated. PMID:27274236

  8. Effect of adjuvants on the action of local anesthetics in isolated rat sciatic nerves

    PubMed Central

    Yilmaz, Eser; Gold, Michael S.; Hough, Karen A.; Gebhart, G.F.; Williams, Brian A.

    2013-01-01

    Background and Objectives There is increasing clinical use of adjuvant drugs to prolong the duration of local anesthetic-induced block of peripheral nerves. However, the mechanistic understanding regarding drug interactions between these compounds in the periphery is quite limited. Accordingly, we undertook this study to determine whether selected adjuvants are efficacious in blocking action potential propagation in peripheral nerves at concentrations used clinically, and whether these drugs influence peripheral nerve block produced by local anesthetics. Methods Isolated rat sciatic nerves were used to assess (1) the efficacy of buprenorphine, clonidine, dexamethasone, or midazolam, alone and in combination, on action potential propagation; and (2) their influence on the blocking actions of local anesthetics ropivacaine and lidocaine. Compound action potentials (CAPs) from A- and C-fibers were studied before and after drug application. Results At estimated clinical concentrations, neither buprenorphine nor dexamethasone affected either A- or C-waves of the CAP. Clonidine produced a small, but significant attenuation of the C-wave amplitude. Midazolam attenuated both A- and C-wave amplitudes, but with greater potency on the C-wave. The combination of clonidine, buprenorphine, and dexamethasone had no influence on the potency or duration of local anesthetic- or midazolam-induced block of A-and C-waves of the CAP. Conclusions These results suggest that the reported clinical efficacy of clonidine, buprenorphine, and dexamethasone influence the actions of local anesthetics via indirect mechanisms. Further identification of these indirect mechanisms may enable the development of novel approaches to achieve longer duration, modality-specific peripheral nerve block. PMID:22430023

  9. Leptin differentially increases sympathetic nerve activity and its baroreflex regulation in female rats: role of oestrogen

    PubMed Central

    Shi, Zhigang; Brooks, Virginia L

    2015-01-01

    Key points Leptin increases sympathetic nerve activity (SNA) in males, which contributes to obesity-induced hypertension; however, whether leptin is equally effective in females is unknown. We report that leptin does increase SNA and heart rate in female rats; however, for lumbar and renal SNA, this action is only evident in pro-oestrus and in oestrogen-treated ovariectomized rats, but not in ovariectomized or dioestrus rats. Leptin increases SNA and heart rate similarly in male and pro-oestrus female rats; however, leptin increases arterial pressure only in males. Blockade of MC3/4 receptors in the paraventricular nucleus (PVN) with SHU9119 decreases SNA in leptin-treated pro-oestrus rats, suggesting that leptin increases SNA in part by increasing α-melanocyte-stimulating hormone drive of PVN presympathetic neurons. Our data establish sex differences in leptin's effects to increase SNA and arterial pressure, which emphasizes the need for enhanced recognition and investigation of sex differences in obesity-induced sympathoexcitation and hypertension. Abstract Obesity and hypertension are commonly associated, and activation of the sympathetic nervous system is considered to be a major contributor, at least in part due to the central actions of leptin. However, while leptin increases sympathetic nerve activity (SNA) in males, whether leptin is equally effective in females is unknown. Here, we show that intracerebroventricular (i.c.v.) leptin increases lumbar (LSNA) and renal (RSNA) SNA and baroreflex control of LSNA and RSNA in α-chloralose anaesthetized female rats, but only during pro-oestrus. In contrast, i.c.v. leptin increased basal and baroreflex control of splanchnic SNA (SSNA) and heart rate (HR) in rats in both the pro-oestrus and dioestrus states. The effects of leptin on basal LSNA, RSNA, SSNA and HR were similar in males and pro-oestrus females; however, i.c.v. leptin increased mean arterial pressure (MAP) only in males. Leptin did not alter LSNA or HR

  10. Transient Heat Hyperalgesia During Resolution of Ropivacaine Sciatic Nerve Block in the Rat

    PubMed Central

    Kolarczyk, Lavinia M.; Williams, Brian A.

    2011-01-01

    Background Preliminary studies using perineural sciatic ropivacaine in rat demonstrated unexpected heat hyperalgesia after block resolution. To better characterize the time course relative to mechanical anesthesia-analgesia, we tested the hypothesis that ropivacaine 0.5% leads to transient heat hyperalgesia in rat independent of mechanical nociception. We also evaluated functional toxicity (e.g., long-term hyperalgesia and/or tactile allodynia 2 weeks post-injection). Methods Under surgical exposure, left sciatic nerve block was performed in 2 groups of adult male rats – ropivacaine (200 μL, 5 mg/mL, n=14) versus vehicle (n=11). The efficacy and duration of block was assessed with serial heat, mechanical (Randall-Selitto testing), and tactile (von Frey-like monofilaments) tests; motor-proprioceptive (rotarod) and sedation tests were employed 1 hr and 7 hr post-injection. The presence of nerve injury was assessed by repeating the heat, tactile, and motor tests 12–14 days post-injection. Results Ropivacaine-induced anesthesia was fully manifest at 1 hr post-injection. At 3 hr post-injection, heat hypersensitivity was present in the setting of resolved mechanical analgesia. All behavioral measures returned to baseline by 2 wk post-injection. There was no evidence of (i) behavioral sedation, (ii) persistent changes in heat or mechanical sensitivity, or (iii) persistent changes in proprioceptive-motor function at 12–14 days post-injection. Conclusions Ropivacaine 0.5% induces transient heat hyperalgesia in the setting of resolved mechanical analgesia, further suggestive of modality and/or nociceptive fiber specificity. Whether this finding partially translates to “rebound pain” after patients’ nerve blocks wear off requires further study. PMID:21451438

  11. Histochemistry of nerve fibres double labelled with anti-TRPV2 antibodies and sensory nerve marker AM1-43 in the dental pulp of rat molars.

    PubMed

    Nishikawa, Sumio

    2008-09-01

    AM1-43 can label sensory nerve fibres and sensory neurons. Permeation of non-selective cation channels of the nerve cell membrane is suggested to be the mechanism responsible for labelling. To identify these channels, two candidates, TRPV1 and TRPV2 were examined by immunocytochemistry in the dental pulp and trigeminal ganglion of rats injected with AM1-43. A part of AM1-43-labelled nerve fibres was also positive for anti-TRPV2 antibody but negative for anti-TRPV1 antibody in the dental pulp. In the trigeminal ganglion, a part of the neuron showed both bright AM1-43 labelling and anti-TRPV2 immunolabelling, but neurons double labelled with AM1-43 and TRPV1 were rare. These results suggest that TRPV2 channels, but not TRPV1 channels, contribute to the fluorescent labelling of AM1-43 in the dental pulp. PMID:18405879

  12. Effects of pelvic, pudendal, or hypogastric nerve cuts on Fos induction in the rat brain following vaginocervical stimulation.

    PubMed

    Pfaus, James G; Manitt, Colleen; Coopersmith, Carol B

    2006-12-30

    In the female rat, genitosensory input is conveyed to the central nervous system predominantly through the pelvic, pudendal, and hypogastric nerves. The present study examined the relative contribution of those three nerves in the expression of Fos immunoreactivity within brain regions previously shown to be activated by vaginocervical stimulation (VCS). Bilateral transection of those nerves, or sham neurectomy, was conducted in separate groups of ovariectomized, sexually-experienced females. After recovery, females were primed with estrogen and progesterone and given either 50 manual VCSs with a lubricated glass rod over the course of 1 h. VCS increased the number of neurons expressing Fos immunoreactivity in the medial preoptic area, lateral septum, bed nucleus of the stria terminalis, ventromedial hypothalamus, and medial amygdala of sham neurectomized females. Transection of the pelvic nerve reduced Fos immunoreactivity in the medial preoptic area, bed nucleus of the stria terminalis, ventromedial hypothalamus, and medial amygdala, whereas transection of the pudendal nerve had no effect. In contrast, transection of the hypogastric nerve increased Fos immunoreactivity in the medial preoptic area and lateral septum, whereas transaction of the pelvic nerve increased Fos immunoreactivity in the lateral septum, following VCS. All females given VCS, except those with pelvic neurectomy, displayed a characteristic immobility during each application. These data confirm that the pelvic nerve is largely responsible for the neural and behavioral effects of VCS, and support a separate function for the hypogastric nerve. PMID:16959279

  13. Evaluating the effect of polytetrafluoroethylene and extractum cepae-heparin-allantoin gel in peripheral nerve injuries in a rat model

    PubMed Central

    Kahraman, Ahmet; Kahveci, Ramazan

    2015-01-01

    BACKGROUND: Peripheral nerves can be injured by congenital, mechanical, thermal or chemical causes. Peripheral nerve injuries are increasing in frequency, particularly in countries that are becoming more industrialized. Nerve and extremity injuries result in work loss and high treatment costs, and can lead to separation of patients from their social environment. Failure of nerve repair causes muscle functional losses, sensory losses and painful neuropathies. OBJECTIVES: To compare the effects of condensed polytetrafluoroethylene (cPTFE) and cPTFE-extractum cepae-heparin-allantoin (cPTFE-EHA) gel compound on nerve and functional recovery, and the prevention of adhesion and scar tissue formation after total peripheral nerve injury repaired by primary suture in a rat model. RESULTS: cPTFE alone and cPTFE-EHA gel was found to provide better functional recovery and nerve regeneration compared with primary repair only. In the macroscopic evaluation, the cPTFE-EHA gel was found to have no negative effect on wound healing and, despite increasing extra-neural scar tissue and adhesions, it had no negative effect on nerve function; in addition, it facilitated functional recovery. CONCLUSIONS: Compared with the cPTFE application alone, the application of perineural cPTFE-EHA gel during peripheral nerve surgery appeared to provide better functional recovery without causing any significant changes in epineural and extraneural scar tissue formation. PMID:25821766

  14. Reinnervation of sweat glands in the rat hind paw following peripheral nerve injury.

    PubMed

    Bharali, L A; Burgess, S A; Lisney, S J; Pearson, D

    1988-08-01

    Electrophysiological experiments have been carried out to investigate the time course and extent of sweat gland reinnervation in the rat hind paw. The first evidence of functional reinnervation after nerve transection was obtained at 12 weeks, when the extent of innervation was 20% of that measured in control animals. By 20 weeks, reinnervation had reached almost 50% of control values but then there was no further improvement up to 52 weeks. These results are comparable to those for skin reinnervation by polymodal nociceptor afferents. PMID:3171090

  15. Characteristics of sympathetic nerve activity in the rat sciatic nerve in response to microstimulation in a sympathetic fascicle in the contralateral side.

    PubMed

    Sato, Daisuke; Shiwaku, Yutaka; Nakamura, Ryoichi; Koizumi, Shuntaro; Feng, Zhonggang; Kusunoki, Masataka; Nakamura, Takao

    2013-01-01

    Microneurography is used for the monitor of various peripheral nerve activities. We recently reported that the electrical stimulation of peripheral sympathetic nerve fascicle via the microelectrode, i.e., microstimulation, temporarily reduced the blood glucose level in rats in case that the stimulation intensity was set high enough to induce small muscle contraction. However, the nature of microstimulation has little been clarified yet. Therefore, in the present study, we first detected sympathetic nerve signal microneurographically in the bilateral sciatic nerves of rats, and one of the microelectrodes was used for the microstimulation (0.25 ms-width pulse train at a rate of 1 Hz) while sympathetic nerve activity (SNA) was recorded in the contralateral side as a parameter of systemic sympathetic effects. The SNA, expressed as action potential rate, was transiently increased 150 ms after each stimulation pulse in case that the stimulation intensity was set not less than -0.1 V from the contraction threshold (around 0.32 V). To confirm that the increase was not caused by the activation of low threshold, thick fibers such as motor nerves in the vicinity of the microelectrode tip, next, a bipolar hook electrode, instead of the microelectrode, was then used in the stimulation side. As a result, the above-mentioned, transient increase in SNA was not observed any more in the contralateral side. These results suggest that systemic SNA could be enhanced with lower stimulation intensity than that inducing muscle contraction, and that thicker fibers may little affect the increase in the contralateral SNA. PMID:24111188

  16. The influence of vascularization of transplanted processed allograft nerve on return of motor function in rats.

    PubMed

    Giusti, Guilherme; Lee, Joo-Yup; Kremer, Thomas; Friedrich, Patricia; Bishop, Allen T; Shin, Alexander Y

    2016-02-01

    Processed nerve allografts have become an alternative to repair segmental nerve defects, with results comparable with autografts regarding sensory recovery; however, they have failed to reproduce comparable motor recovery. The purpose of this study was to determine how revascularizaton of processed nerve allograft would affect motor recovery. Eighty-eight rats were divided in four groups of 22 animals each. A unilateral 10-mm sciatic nerve defect was repaired with allograft (group I), allograft wrapped with silicone conduit (group II), allograft augmented with vascular endothelial growth factor (group III), or autograft (group IV). Eight animals from each group were sacrificed at 3 days, and the remaining animals at 16 weeks. Revascularization was evaluated by measuring the graft capillary density at 3 days and 16 weeks. Measurements of ankle contracture, compound muscle action potential, tibialis anterior muscle weight and force, and nerve histomorphometry were performed at 16 weeks. All results were normalized to the contralateral side. The results of capillary density at 3 days were 0.99% ± 1.3% for group I, 0.33% ± 0.6% for group II, 0.05% ± 0.1% for group III, and 75.6% ± 45.7% for group IV. At 16 weeks, the results were 69.9% ± 22.4% for group I, 37.0% ± 16.6% for group II, 84.6% ± 46.6% for group III, and 108.3% ± 46.8% for group IV. The results of muscle force were 47.5% ± 14.4% for group I, 21.7% ± 13.5% for group II, 47.1% ± 7.9% for group III, and 54.4% ± 10.6% for group IV. The use of vascular endothelial growth factor in the fashion used in this study improved neither the nerve allograft short-term revascularization nor the functional motor recovery after 16 weeks. Blocking allograft vascularization from surrounding tissues was detrimental for motor recovery. The processed nerve allografts used in this study showed similar functional motor recovery compared with that of the autograft. PMID

  17. Intestinal mucosal mast cells in normal and nematode-infected rat intestines are in intimate contact with peptidergic nerves.

    PubMed Central

    Stead, R H; Tomioka, M; Quinonez, G; Simon, G T; Felten, S Y; Bienenstock, J

    1987-01-01

    Inflammatory or allergic conditions, as well as situations where healing and repair processes occur, are characterized by the presence of increased numbers of mast cells. Previous work on the effect of neuropeptides on mast cell mediator release showed that only substance P caused such release from intestinal mucosal mast cells [Shanahan, F., Denburg, J. A., Fox, J., Bienenstock, J. & Befus, A. D. (1985) J. Immunol. 135, 1331-1337]. Accordingly, we investigated the microanatomical relationship between mast cells and enteric nerves in normal rat intestine and parasite-infected rat intestine, in which mucosal mast cell hyperplasia occurs. Combined immunohistochemistry for neuron-specific enolase and staining with alcian blue at pH 0.5 was employed on paraffin-embedded sections of normal and Nippostrongylus brasiliensis-infected rat jejunum. Sixty-seven percent of intestinal mucosal mast cells were touching subepithelial nerves, and an additional 20% were within 2 micron of nerves. Assessment of the proportion of the lamina propria occupied by mast cells (12.5%), the average mast cell area (121 +/- 28 microns 2), and the density of enteric nerves (one per 788 +/- 151 microns 2) suggested that the association was 5 times greater than would be expected by chance alone (P less than 0.0001). In consecutive sections, the nerves in contact with mast cells were also shown to contain substance P and/or calcitonin-gene-related peptide. Electron microscopy confirmed this association: 8% of the mast cells in infected rats exhibited membrane-membrane contact with unmyelinated axons containing 70- to 170-nm dense-core vesicles, and an additional 31% were situated less than 250 nm from nerves. Other mast cells appeared to embrace nerve bundles through the projection of lamellopodia. These data provide systematic quantitative evidence that a structural foundation for communication between the immune and nervous systems exists in the rat gastrointestinal tract. Images PMID:2437589

  18. Comparison of short-term effects of insulin and essential fatty acids on the slowed nerve conduction of streptozotocin diabetes in rats.

    PubMed

    Julu, P O; Mutamba, A

    1991-11-01

    Early effects of insulin and essential fatty acids on nerve conduction were studied. Insulin-dependent diabetes was induced in rats using streptozocin (65 mg/kg, i.p.); control rats were treated with buffer. Five weeks later, diabetic rats were divided into 5 groups. Two groups were given oral essential fatty acids (75% linoleic and 9% gamma-linolenic acids) for a further 3 and 5 days, respectively. Two other groups received subcutaneous insulin for a further 3 or 5 days. A group of diabetic rats were left without further treatment. Motor nerve conduction velocity was measured terminally in all rats by stimulating the sciatic nerve and recording EMGs in the gastrocnemius muscle under urethane anaesthesia. Sensory nerve conduction velocity was measured by stimulating and recording from the saphenous nerve trunk. Diabetic rats had significantly slowed motor and sensory nerve conduction velocities after 5 weeks (16.7%, P less than 0.001). Three days treatment with either insulin or fatty acids corrected the slowed motor nerve conduction velocity to a normal level. Conduction velocity in myelinated sensory nerves was still 10% slower in diabetic rats treated with insulin for 3 days (P less than 0.01). It was above the control level by 11% in diabetic rats treated with fatty acids for the same period (P less than 0.01). Conduction velocities in both sensory and motor nerves were normal in diabetic rats treated with either insulin or fatty acids for 5 days. It was concluded that both insulin and essential fatty acids had early effects on nerve conduction in diabetic rats. The speed of their actions, and the magnitudes of responses were different in sensory and motor nerves. PMID:1663993

  19. Peripheral nerve metabolism and zinc levels in streptozotocin induced diabetic rats. Effect of diets high in fish and corn oil

    SciTech Connect

    Burke, J.P.; Fenton, M.R. )

    1991-03-15

    This study was designed to assess the effects of diets high in fish and corn oil on peripheral nerve metabolism in streptozotocin (STZ) induced diabetic rats. A type I diabetic state was induced in female Sprague-Dawley rats by injection of STZ. Animals were divided into three dietary groups; normal rat chow, high corn oil diet and high fish oil diet. After 4 weeks animals were analyzed for nerve conduction velocity, bled and then sacrificed. Sciatic nerves were removed, processed and several biochemical parameters determined. Plasma zinc levels were elevated in the STZ normal chow group compared to non-diabetic controls. Both corn oil and fish oil diets tended to eliminate the rise in plasma zinc. Differences in subcellular distribution of zinc in sciatic nerves were also observed. Normal chow STZ animals displayed a 20% decrease in nerve conduction velocity compared to control. Dietary supplementation with either fish or corn oil seemed to ameliorate these effects. Biochemical analysis of Na{sup +}-K{sup +}-ATPase and protein kinase C revealed a decrease in activity in normal chow animals compared to control groups. Again, dietary intervention with either fish or corn oil seemed to return these activities back to normal. The results suggest a link between zinc metabolism and peripheral nerve metabolism which can be modified by dietary intervention.

  20. Contralateral Metabolic Activation Related to Plastic Changes in the Spinal Cord after Peripheral Nerve Injury in Rats

    PubMed Central

    Won, Ran; Lee, Bae Hwan

    2015-01-01

    We have previously reported the crossed-withdrawal reflex in which the rats with nerve injury developed behavioral pain responses of the injured paw to stimuli applied to the contralateral uninjured paw. This reflex indicates that contralateral plastic changes may occur in the spinal cord after unilateral nerve injury. The present study was performed to elucidate the mechanisms and morphological correlates underlying the crossed-withdrawal reflex by using quantitative 14C-2-deoxyglucose (2-DG) autoradiography which can examine metabolic activities and spatial patterns simultaneously. Under pentobarbital anesthesia, rats were subjected to unilateral nerve injury. Mechanical allodynia was tested for two weeks after nerve injury. After nerve injury, neuropathic pain behaviors developed progressively. The crossed-withdrawal reflex was observed at two weeks postoperatively. Contralateral enhancement of 2-DG uptake in the ventral horn of the spinal cord to electrical stimulation of the uninjured paw was observed. These results suggest that the facilitation of information processing from the uninjured side to the injured side may contribute to the crossed-withdrawal reflex by plastic changes in the spinal cord of nerve-injured rats. PMID:26491570

  1. Contralateral Metabolic Activation Related to Plastic Changes in the Spinal Cord after Peripheral Nerve Injury in Rats.

    PubMed

    Won, Ran; Lee, Bae Hwan

    2015-01-01

    We have previously reported the crossed-withdrawal reflex in which the rats with nerve injury developed behavioral pain responses of the injured paw to stimuli applied to the contralateral uninjured paw. This reflex indicates that contralateral plastic changes may occur in the spinal cord after unilateral nerve injury. The present study was performed to elucidate the mechanisms and morphological correlates underlying the crossed-withdrawal reflex by using quantitative (14)C-2-deoxyglucose (2-DG) autoradiography which can examine metabolic activities and spatial patterns simultaneously. Under pentobarbital anesthesia, rats were subjected to unilateral nerve injury. Mechanical allodynia was tested for two weeks after nerve injury. After nerve injury, neuropathic pain behaviors developed progressively. The crossed-withdrawal reflex was observed at two weeks postoperatively. Contralateral enhancement of 2-DG uptake in the ventral horn of the spinal cord to electrical stimulation of the uninjured paw was observed. These results suggest that the facilitation of information processing from the uninjured side to the injured side may contribute to the crossed-withdrawal reflex by plastic changes in the spinal cord of nerve-injured rats. PMID:26491570

  2. Gamma Knife Irradiation of Injured Sciatic Nerve Induces Histological and Behavioral Improvement in the Rat Neuropathic Pain Model

    PubMed Central

    Yagasaki, Yuki; Hayashi, Motohiro; Tamura, Noriko; Kawakami, Yoriko

    2013-01-01

    We examined the effects of gamma knife (GK) irradiation on injured nerves using a rat partial sciatic nerve ligation (PSL) model. GK irradiation was performed at one week after ligation and nerve preparations were made three weeks after ligation. GK irradiation is known to induce immune responses such as glial cell activation in the central nervous system. Thus, we determined the effects of GK irradiation on macrophages using immunoblot and histochemical analyses. Expression of Iba-1 protein, a macrophage marker, was further increased in GK-treated injured nerves as compared with non-irradiated injured nerves. Immunohistochemical study of Iba-1 in GK-irradiated injured sciatic nerves demonstrated Iba-1 positive macrophage accumulation to be enhanced in areas distal to the ligation point. In the same area, myelin debris was also more efficiently removed by GK-irradiation. Myelin debris clearance by macrophages is thought to contribute to a permissive environment for axon growth. In the immunoblot study, GK irradiation significantly increased expressions of βIII-tubulin protein and myelin protein zero, which are markers of axon regeneration and re-myelination, respectively. Toluidine blue staining revealed the re-myelinated fiber diameter to be larger at proximal sites and that the re-myelinated fiber number was increased at distal sites in GK-irradiated injured nerves as compared with non-irradiated injured nerves. These results suggest that GK irradiation of injured nerves facilitates regeneration and re-myelination. In a behavior study, early alleviation of allodynia was observed with GK irradiation in PSL rats. When GK-induced alleviation of allodynia was initially detected, the expression of glial cell line-derived neurotrophic factor (GDNF), a potent analgesic factor, was significantly increased by GK irradiation. These results suggested that GK irradiation alleviates allodynia via increased GDNF. This study provides novel evidence that GK irradiation of

  3. Local Effect of Heparin Binding Neurotrophic Factor Combined With Chitosan Entubulization on Sciatic Nerve Repair in Rats

    PubMed Central

    Mehrshad, Ali; Seddighnia, Ashkan; Shadabi, Mohammadreza; Najafpour, Alireza; Mohammadi, Rahim

    2016-01-01

    Objective: To assess the effect of on sciatic nerve regeneration in animal model of rat. Methods: Seventy-five male Wistar rats were divided into five experimental groups randomly (each group containing 15 animals): Sham operation group (SHAM), autograft group (AUTO), transected control (TC), chitosan conduit (CHIT) and heparin binding neurotrophic factor treated group (CHIT/HBNF). In AUTO group a segment of sciatic nerve was transected and reimplanted reversely. In SHAM group sciatic nerve was exposed and manipulated. In transected group left sciatic nerve was transected and stumps were fixed in adjacent muscle (TC). In treatment group defect was bridged using a chitosan conduit (CHIT) filled with 10 µL HBNF (CHIT/HBNF). Each group was subdivided into four subgroups of five animals each and nerve fibers were studied in a 12-week period. Results: Behavioral, functional, biomechanical, electrophysiological and gastrocnemius muscle mass findings and morphometric indices confirmed faster recovery of regenerated axons in treatment group than in CHIT group (P=0.001). Immunohistochemical reactions to S-100 in treatment group were more positive than that in CHIT group. Conclusion: Local administration of improved functional recovery and morphometric indices of sciatic nerve. It could be considered as an effective treatment for peripheral nerve repair in practice. PMID:27331064

  4. Over-expression of copper/zinc superoxide dismutase in the median preoptic nucleus attenuates chronic angiotensin II-induced hypertension in the rat.

    PubMed

    Collister, John P; Bellrichard, Mitch; Drebes, Donna; Nahey, David; Tian, Jun; Zimmerman, Matthew C

    2014-01-01

    The brain senses circulating levels of angiotensin II (AngII) via circumventricular organs, such as the subfornical organ (SFO), and is thought to adjust sympathetic nervous system output accordingly via this neuro-hormonal communication. However, the cellular signaling mechanisms involved in these communications remain to be fully understood. Previous lesion studies of either the SFO, or the downstream median preoptic nucleus (MnPO) have shown a diminution of the hypertensive effects of chronic AngII, without providing a clear explanation as to the intracellular signaling pathway(s) involved. Additional studies have reported that over-expressing copper/zinc superoxide dismutase (CuZnSOD), an intracellular superoxide (O2·-) scavenging enzyme, in the SFO attenuates chronic AngII-induced hypertension. Herein, we tested the hypothesis that overproduction of O2·- in the MnPO is an underlying mechanism in the long-term hypertensive effects of chronic AngII. Adenoviral vectors encoding human CuZnSOD (AdCuZnSOD) or control vector (AdEmpty) were injected directly into the MnPO of rats implanted with aortic telemetric transmitters for recording of arterial pressure. After a 3 day control period of saline infusion, rats were intravenously infused with AngII (10 ng/kg/min) for ten days. Rats over-expressing CuZnSOD (n = 7) in the MnPO had a blood pressure increase of only 6 ± 2 mmHg after ten days of AngII infusion while blood pressure increased 21 ± 4 mmHg in AdEmpty-infected rats (n = 9). These results support the hypothesis that production of O2·- in the MnPO contributes to the development of chronic AngII-dependent hypertension. PMID:25474089

  5. Derangement of autonomic nerve control in rat with right ventricular failure.

    PubMed

    Sanyal, S N.; Ono, K

    2002-06-01

    The effects of right ventricular hypertrophy and eventual right ventricular failure on autonomic nerve regulation of heart rate variability were investigated using rats with monocrotaline (MCT)-induced pulmonary hypertension. ECG signals were obtained from a radio transmitter placed into the subcutaneous pouch in the back of the male MCT-treated and control rats for 30 min every 6 h at a sample rate of 5 kHz with or without injection of atropine (2 mg/kg I.P.) or propranolol (4 mg/kg I.P.), in a room equipped with a climate controller. Heart rate (HR) and HR variability (HRV) were analyzed in each group by power spectrograms obtained by the fast-Fourier transform algorithm. The RR interval, total power (TP), low-frequency (LF) power (0.04-0.73 Hz), high-frequency (HF) power (0.73-2 Hz) and LF/HF (L/H) ratio were measured. HR was significantly increased in the MCT-treated rats (P<0.001), which also presented lower HRV than that of the control Wistar rats; TP (P<0.05) and HF (P<0.05) power, but not the L/H ratio, were significantly lower than that of the control rats. Responses of these parameters to a muscarinic antagonist (atropine: 2 mg/kg) and a beta-adrenergic antagonist (propranolol: 4 mg/kg), however, remained intact in the MCT-treated rats. Only the parasympathetic component of autonomic nervous controls of HRV was deranged in rats with MCT-induced right ventricular failure. PMID:12039652

  6. Effects of Perineural Administration of Dexmedetomidine in Combination with Levobupivacaine in a Rat Sciatic Nerve Block☆

    PubMed Central

    Ali Erdogan, Mehmet; Polat, Alaaddin; Yucel, Aytac; Aydogan, Mustafa Said; Parlakpinar, Hakan; Tekin, Suat; Durmus, Mahmut; Ozcan Ersoy, Mehmet

    2013-01-01

    Objective The aim of this study was to assess if perineural administration of dexmedetomidine combined with levobupivacaine increases the duration of the sensory and motor blockade of a sciatic peripheral nerve block in rats. Methods Forty male Sprague–Dawley rats were randomly divided into 5 experimental groups: Group 1, sham; Group 2, perineural levobupivacaine (0.2 mL of a 0.5% solution) and subcutaneous saline; Group 3, perineural levobupivacaine (0.2 mL of a 0.5% solution) plus dexmedetomidine (20 µg/kg dexmedetomidine) and subcutaneous saline; Group 4, perineural saline and subcutaneous dexmedetomidine; and Group 5, perineural saline and subcutaneous saline. Pain reflexes in response to a thermal stimulus were measured at 0 and 240 minutes after drug administration by using a hot-plate and tail-flick tests. Neurobehavioral status, including sensory and motor functions, was assessed by an investigator who was blinded to the experimental groups every 30 minutes until normal functioning resumed. Results The sensory and motor blockades of the rats did not increase in the treatment with dexmedetomidine plus levobupivacaine when compared with the treatment with levobupivacaine alone at all the time points (P > 0.05). Compared with rats in Group 2, those in Group 3 showed significantly higher latency times at 30 and 60 minutes in the hot plate test (P < 0.01). At 30 and 60 minutes, the latency times of the rats in Group 3 were longer than those in Group 2 in the tail-flick test (P < 0.01). Furthermore, the durations of the complete sensory and motor blockade were similar when treatment with levobupivacaine plus dexmedetomidine was compared with treatment with levobupivacaine alone. Conclusions A 20µg/kg dose of dexmedetomidine added to levobupivacaine did not increase the duration of the sensory and motor blockades in rats. However, treatment with dexmedetomidine plus levobupivacaine increased the quality of analgesia in rats. PMID:24385106

  7. The phytoestrogenic Cyclopia extract, SM6Met, increases median tumor free survival and reduces tumor mass and volume in chemically induced rat mammary gland carcinogenesis.

    PubMed

    Visser, Koch; Zierau, Oliver; Macejová, Dana; Goerl, Florian; Muders, Michael; Baretton, Gustavo B; Vollmer, Günter; Louw, Ann

    2016-10-01

    SM6Met, a phytoestrogenic extract of Cyclopia subternata indigenous to the Western Cape province of South Africa, displays estrogenic attributes with potential for breast cancer chemoprevention. In this study, we report that SM6Met, in the presence of estradiol, induces a significant cell cycle G0/G1 phase arrest similar to the selective estrogen receptor modulator, tamoxifen. Furthermore, as a proof of concept, in the N-Methyl-N-nitrosourea induced rat mammary gland carcinogenesis model, SM6Met increases tumor latency by 7days and median tumor free survival by 42 days, while decreasing palpable tumor frequency by 32%, tumor mass by 40%, and tumor volume by 53%. Therefore, the current study provides proof of concept that SM6Met has definite potential as a chemopreventative agent against the development and progression of breast cancer. PMID:27142456

  8. Effects of vitamin B12 on the corneal nerve regeneration in rats.

    PubMed

    Romano, Maria Rosaria; Biagioni, Francesca; Carrizzo, Albino; Lorusso, Massimo; Spadaro, Angelo; Micelli Ferrari, Tommaso; Vecchione, Carmine; Zurria, Monia; Marrazzo, Giuseppina; Mascio, Giada; Sacchetti, Benedetto; Madonna, Michele; Fornai, Francesco; Nicoletti, Ferdinando; Lograno, Marcello Diego

    2014-03-01

    The study was designed to investigate the effects of a new ophthalmic solution containing 0.05% vitamin B12 0.05% on corneal nerve regeneration in rats after corneal injury. Eyes of anesthetized male Wistar rats were subjected to corneal injury by removing the corneal epithelium with corneal brush (Algerbrush). After the epithelial debridement, the right eye of each animal received the instillation of one drop of the ophthalmic solution containing vitamin B12 0.05% plus taurine 0.5% and sodium hyaluronate 0.5% four time per day for 10 or 30 days. Left eyes were used as control and treated with solution containing taurine 0.5% and sodium hyaluronate 0.5% alone following the same regimen. Fluorescein staining by slit-lamp and morphological analysis was used to determine corneal wound healing. Immunohistochemistry, immunoblot and confocal microscopy were used to examine corneal re-innervation. Slit-lamp and histological analyses showed that re-epithelization of the corneas was accelerated in rats treated with vitamin B12. A clear-cut difference between the two groups of rats was seen after 10 days of treatment, whereas a near-to-complete re-epithelization was observed in both groups at 30 days. Vitamin B12 treatment had also a remarkable effect on corneal re-innervation, as shown by substantial increased in the expression of neurofilament 160 and β-III tubulin at both 10 and 30 days. The presence of SV2A-positive nerve endings suggests the presence of synapse-like specialized structures in corneal epithelium of the eye treated with vitamin B12. Our findings suggest that vitamin B12 treatment represents a powerful strategy to accelerate not only re-epithelization but also corneal re-innervation after mechanical injury. PMID:24486457

  9. Ex Vivo Assay of Electrical Stimulation to Rat Sciatic Nerves: Cell Behaviors and Growth Factor Expression.

    PubMed

    Du, Zhiyong; Bondarenko, Olexandr; Wang, Dingkun; Rouabhia, Mahmoud; Zhang, Ze

    2016-06-01

    Neurite outgrowth and axon regeneration are known to benefit from electrical stimulation. However, how neuritis and their surroundings react to electrical field is difficult to replicate by monolayer cell culture. In this work freshly harvested rat sciatic nerves were cultured and exposed to two types of electrical field, after which time the nerve tissues were immunohistologically stained and the expression of neurotrophic factors and cytokines were evaluated. ELISA assay was used to confirm the production of specific proteins. All cell populations survived the 48 h culture with little necrosis. Electrical stimulation was found to accelerate Wallerian degeneration and help Schwann cells to switch into migratory phenotype. Inductive electrical stimulation was shown to upregulate the secretion of multiple neurotrophic factors. Cellular distribution in nerve tissue was altered upon the application of an electrical field. This work thus presents an ex vivo model to study denervated axon in well controlled electrical field, bridging monolayer cell culture and animal experiment. It also demonstrated the critical role of electrical field distribution in regulating cellular activities. PMID:26516696

  10. Enhanced 5-hydroxytryptamine (5-HT) release from vascular adrenergic nerves in spontaneously hypertensive rats

    SciTech Connect

    Kawasaki, H.; Urabe, M.; Takasaki, K.

    1986-03-01

    The release of 5-HT from vascular adrenergic nerves was compared between normotensive Wistar Kyoto rats (WKY) and SHR. The mesenteric vascular bed isolated from WKY and SHR was perfused with Krebs solution at a constant flow rate of 5 ml/min. Periarterial nerve stimulation (PNS) was delivered at 4 to 16 Hz for 30 sec. In the SHR preparation, the pressor response to PNS, previously decreased by prazonsin (50 nM), was greatly potentiated after treatment with 5-HT(1 ..mu..M) for 15 min and a frequency-dependent pressor response to PNS reappeared, whereas the 5-HT treatment did not alter the pressor response to exogenous norepinephrine (1 nmol) previously reduced by prazonsin. The potentiation of pressor response to PNS after 5-HT treatment was small in the WKY preparation. This potentiation in both WKY and SHR did not occur in the presence of ketanserin (10 nM). In the preparation labeled with (/sup 3/H)-5-HT, PNS (4-16 Hz) evoked a frequency-dependent increase of (/sup 3/H)-efflux, which was abolished by treatment with tetrodotoxin (100 nM) or 6-hydroxydopamine (50 mg/kg i.p. x 2) and in calcium-free Krebs solution. The PNS evoked-(/sup 3/H)-efflux was much greater in SHR than WKY. These results suggest that the release of 5-HT from vascular adrenergic nerves by PNS is enhanced in the SHR preparation.

  11. Proteomic analysis of microdissected facial nuclei of the rat following facial nerve injury.

    PubMed

    Melle, Christian; Ernst, Günther; Grosheva, Maria; Angelov, Doychin N; Irintchev, Andrey; Guntinas-Lichius, Orlando; von Eggeling, Ferdinand

    2009-12-15

    Recent studies using molecular and genetic techniques just have started to elucidate the complex process that drives successful peripheral nerve regeneration. Introducing proteomics to this field, we unilaterally performed a facial nerve axotomy in 13 adult Wistar rats. Seven days later, a total of 40 20-microm coronary cryostat sections of the operated and contralateral unoperated nucleus facialis were microdissected. On the one hand, microdissected areas were pooled for each side, lysed and applied to ProteinChip Arrays. On the other hand, one microdissected area from the right and left facial nucleus each was directly placed on the affinity chromatographic array. Facial motoneurons were lysed in situ and released their proteins to spatially defined points. 215 laser addressable distinct positions across the surface of the spot enabled a high spatial resolution of measured protein profiles for the analysed tissue area. Protein profiles of the single positions were plotted over the used tissue section to visualize their distribution. The comparative analysis of the protein lysates from operated and normal nuclei facialis revealed, for both approaches used, differentially expressed proteins. Although by direct application of one cryostat section only a few hundred motoneurons were analysed, results comparable to these using lysates were obtained. Additionally, the applied technique revealed differences in the intensity distribution of several proteins of unknown function in the lesioned in comparison to the contralateral normal facial nucleus. This proteomic analysis with ultra high sensitivity paired with potential for a spatial resolution is a promising methodology for peripheral nerve regeneration studies. PMID:19748522

  12. Tolerance to repeated stress in rats with lesions of the serotoninergic neurons of the Median Raphe Nucleus and chronically treated with imipramine.

    PubMed

    Silva, K; Carvalho, M C; Padovan, C M

    2016-04-01

    Repeated exposure to aversive events leads to the development of tolerance to stress, which involves the serotonergic pathway originated in the Median Raphe Nucleus (MnRN) to the Dorsal Hippocampus (DH). However, it is not clear whether these lesion-induced deficits can be attenuated by treatment with antidepressants. Therefore, the aim of this work was to investigate the effects of chronic treatment with Imipramine (IMI) in rats with lesions in the MnRN and exposed to restraint stress. Male Wistar rats with or without neurochemical lesions of the MnRN serotonergic neurons with the neurotoxin 5,7-DHT were submitted to acute (2h) or chronic restraint (2h/day/seven consecutive days) and treated with saline (1 ml/kg) or imipramine (15 mg/kg) via intraperitoneal twice a day during the same period. In acutely restrained rats, stress occurred on the last day of treatment. Test in the elevated plus maze (EPM) was performed 24h later. After EPM test, animals were sacrificed and had their brains removed. Dorsal hippocampus and striatum were dissected and the levels of 5-HT and 5-hydroxy-indoleacetic acid (5-HIAA) measured by HPLC analysis. Our results showed that in control rats exposure to acute restraint stress decreased exploration of the open and enclose arms of the EPM, an effect that was attenuated by imipramine. In rats with 5,7-DHT lesions, acute restraint did not change the exploration of the EPM, independently of the treatment. On the other hand, when chronically restrained, saline treated rat with 5,7-DHT lesion showed a reduced exploration of the open arms of the EPM. This effect was attenuated by simultaneous treatment with imipramine. HPLC analysis showed significantly decreases on 5-HT and 5-HIAA levels in the hippocampus, but not in the striatum. These later results confirm that 5,7-DHT lesions of the MnRN had significant impact on the serotonergic projections to the dorsal hippocampus which seems to be essential for the development of tolerance to repeated

  13. Temporal distribution of the ganglion cell volleys in the normal rat optic nerve

    PubMed Central

    Galambos, Robert; Szabó-Salfay, Orsolya; Barabás, Péter; Pálhalmi, János; Szilágyi, Nóra; Juhász, Gábor

    2000-01-01

    We describe experiments on behaving rats with electrodes implanted on the cornea, in the optic chiasm, and on the visual cortex; in addition, two red light-emitting diodes (LED) are permanently attached to the skull over the left eye. Recordings timelocked to the LED flashes reveal both the local events at each electrode site and the orderly transfer of visual information from retina to cortex. The major finding is that every stimulus, regardless of its luminance, duration, or the state of retinal light adaptation, elicits an optic nerve volley with a latency of about 10 ms and a duration of about 300 ms. This phenomenon has not been reported previously, so far as we are aware. We conclude that the retina, which originates from the forebrain of the developing embryo, behaves like a typical brain structure: it translates, within a few hundred milliseconds, the chemical information in each pattern of bleached photoreceptors into a corresponding pattern of ganglion cell neuronal information that leaves via the optic nerve. The attributes of each rat ganglion cell appear to include whether the retinal neuropile calls on it to leave after a stimulus and, if so when, within a 300-ms poststimulus epoch. The resulting retinal analysis of the scene, on arrival at the cortical level, is presumed to participate importantly in the creation of visual perceptual experiences. PMID:11078526

  14. Respiratory modulation of sympathetic nerve activity is enhanced in male rat offspring following uteroplacental insufficiency.

    PubMed

    Menuet, C; Wlodek, M E; Fong, A Y; Allen, A M

    2016-06-01

    Sympathetic nerve activity to the cardiovascular system displays prominent respiratory-related modulation which leads to the generation of rhythmic oscillations in blood pressure called Traube-Hering waves. An amplification of this respiratory modulation of sympathetic activity is observed in hypertension of both genetic, the spontaneously hypertensive rat, and induced, chronic intermittent hypoxia or maternal protein restriction during gestation, origin. Male offspring of mothers with uteroplacental insufficiency, induced by bilateral uterine vessel ligation at 18 days of gestation, are also hypertensive in adulthood. In this study we examined whether these male offspring display altered respiratory modulation of sympathetic activity at pre-hypertensive ages compared to controls. Respiratory, cardiovascular and sympathetic parameters were examined using the working heart-brainstem preparation in 35 day old male rats that had reduced birth weight due to uteroplacental insufficiency. Whilst all respiratory parameters were not different between groups, we observed an enhanced respiratory-related burst of thoracic sympathetic nerve activity and amplified Traube-Hering waves in the growth-restricted group. This group also showed an increased sympathetic and bradycardic response to activation of peripheral chemoreceptors. The observations add support to the view that altered respiratory modulation of sympathetic activity represents a common mechanism involved in the development of several forms of hypertension. PMID:26593642

  15. Nerve growth factor signaling following unilateral pelvic ganglionectomy in the rat ventral prostate is age dependent.

    PubMed

    Podlasek, Carol A; Ghosh, Rudrani; Onur Cakir, Omer; Bond, Christopher; McKenna, Kevin E; McVary, Kevin T

    2013-11-01

    Benign prostatic hyperplasia (BPH) is a serious health concern and is an underlying cause of lower urinary tract symptoms (LUTS) in many men. In affected men, LUTS/BPH is believed to result from benign proliferation of the prostate resulting in bladder outlet obstruction. Postnatal growth of the prostate is controlled via growth factor and endocrine mechanisms. However, little attention had been given to the function of the autonomic nervous system in prostate growth and differentiation. Nerve growth factor (NGF) is a prostatic mitogen that has a trophic role in autonomic sensory end organ interaction. In this study, we examine how the autonomic nervous system influences prostate growth as a function of age by quantifying NGF in the rat ventral prostate (VP) after pelvic ganglionectomy. Unilateral pelvic ganglionectomy was performed on postnatal days 30 (P30), 60 and 120 Sprague-Dawley rats in comparison to sham controls (n=39). Semiquantitative RT-PCR, Western blotting and immunohistochemical analysis for NGF were performed on denervated, intact (contralateral side) and sham control VP 7 days after surgery. Ngf RNA expression was significantly increased in the denervated and intact hyperplastic VP. Western blotting showed age-dependent increases in NGF protein at P60 in the contralateral intact VP. NGF was localized in the nerves, basal cells and columnar epithelium of the prostatic ducts. Denervation causes age-dependent increases in NGF in the VP, which is a potential mechanism by which the autonomic nervous system may regulate prostate growth and lead to BPH/LUTS. PMID:23872662

  16. Repetitive Diving in Trained Rats Still Increases Fos Production in Brainstem Neurons after Bilateral Sectioning of the Anterior Ethmoidal Nerve

    PubMed Central

    McCulloch, Paul F.; Warren, Erik A.; DiNovo, Karyn M.

    2016-01-01

    This research was designed to investigate the role of the anterior ethmoidal nerve (AEN) during repetitive trained diving in rats, with specific attention to activation of afferent and efferent brainstem nuclei that are part of this reflexive response. The AEN innervates the nose and nasal passages and is thought to be an important component of the afferent limb of the diving response. Male Sprague-Dawley rats (N = 24) were trained to swim and dive through a 5 m underwater maze. Some rats (N = 12) had bilateral sectioning of the AEN, others a Sham surgery (N = 12). Twelve rats (6 AEN cut and 6 Sham) had 24 post-surgical dive trials over 2 h to activate brainstem neurons to produce Fos, a neuronal activation marker. Remaining rats were non-diving controls. Diving animals had significantly more Fos-positive neurons than non-diving animals in the caudal pressor area, ventral medullary dorsal horn, ventral paratrigeminal nucleus, nucleus tractus solitarius, rostral ventrolateral medulla, Raphe nuclei, A5, Locus Coeruleus, and Kölliker-Fuse area. There were no significant differences in brainstem Fos labeling in rats diving with and without intact AENs. Thus, the AENs are not required for initiation of the diving response. Other nerve(s) that innervate the nose and nasal passages, and/or suprabulbar activation of brainstem neurons, may be responsible for the pattern of neuronal activation observed during repetitive trained diving in rats. These results help define the central neuronal circuitry of the mammalian diving response. PMID:27148082

  17. Repetitive Diving in Trained Rats Still Increases Fos Production in Brainstem Neurons after Bilateral Sectioning of the Anterior Ethmoidal Nerve.

    PubMed

    McCulloch, Paul F; Warren, Erik A; DiNovo, Karyn M

    2016-01-01

    This research was designed to investigate the role of the anterior ethmoidal nerve (AEN) during repetitive trained diving in rats, with specific attention to activation of afferent and efferent brainstem nuclei that are part of this reflexive response. The AEN innervates the nose and nasal passages and is thought to be an important component of the afferent limb of the diving response. Male Sprague-Dawley rats (N = 24) were trained to swim and dive through a 5 m underwater maze. Some rats (N = 12) had bilateral sectioning of the AEN, others a Sham surgery (N = 12). Twelve rats (6 AEN cut and 6 Sham) had 24 post-surgical dive trials over 2 h to activate brainstem neurons to produce Fos, a neuronal activation marker. Remaining rats were non-diving controls. Diving animals had significantly more Fos-positive neurons than non-diving animals in the caudal pressor area, ventral medullary dorsal horn, ventral paratrigeminal nucleus, nucleus tractus solitarius, rostral ventrolateral medulla, Raphe nuclei, A5, Locus Coeruleus, and Kölliker-Fuse area. There were no significant differences in brainstem Fos labeling in rats diving with and without intact AENs. Thus, the AENs are not required for initiation of the diving response. Other nerve(s) that innervate the nose and nasal passages, and/or suprabulbar activation of brainstem neurons, may be responsible for the pattern of neuronal activation observed during repetitive trained diving in rats. These results help define the central neuronal circuitry of the mammalian diving response. PMID:27148082

  18. Cauda equina repair in the rat: part 1. Stimulus-evoked EMG for identifying spinal nerves innervating intrinsic tail muscles.

    PubMed

    Blaskiewicz, Don J; Smirnov, Igor; Cisu, Tudor; DeRuisseau, Lara R; Stelzner, Dennis J; Calancie, Blair

    2009-08-01

    Cauda equina injuries may produce severe leg and pelvic floor dysfunction, for which no effective treatments exist. We are developing a rat cauda equina injury model to allow nerve root identification and surgical repair. One possible difficulty in implementing any repair strategy after trauma in humans involves the correct identification of proximal and distal ends of nerve roots separated by the injury. Two series of studies were carried out. In Series 1, we electrically stimulated segmental contributors to the dorsal and ventral caudales nerves in order to characterize the recruitment patterns of muscles controlling rat tail movements. In Series 2, we attempted to identify individual nerve roots forming the cauda equina by both level of origin and function (i.e., dorsal or ventral), based solely upon the recruitment patterns in response to electrical stimulation. For Series 1 studies, electrical stimulation of the segmental contributors showed that all nerve roots-from the sixth lumbar to the first coccygeal-contributed to recruitment of muscles found at the base of the tail. Intrinsic tail muscles lying more distally in the tail showed a more root-specific pattern of innervation. For Series 2, the rate of successful identification of an unknown nerve root as being ventral was very high (>95%), and only somewhat lower (approximately 80%) for dorsal roots. Correctly identifying the level of origin of that root was more difficult, but for ventral roots this rate still exceeded 90%. Using the rat cauda equina model, we have shown that stimulus-evoked EMG can be used to identify ventral nerve roots innervating tail muscles with a high degree of accuracy. These findings support the feasibility of using this conceptual approach for identifying and repairing damaged human cauda equina nerve roots based on stimulus-evoked recruitment of muscles in the leg and pelvic floor. PMID:19203211

  19. Haemodynamic Responses to Selective Vagal Nerve Stimulation under Enalapril Medication in Rats

    PubMed Central

    Gierthmuehlen, Mortimer; Stieglitz, Thomas; Zentner, Josef; Plachta, Dennis T. T.

    2016-01-01

    Selective vagal nerve stimulation (sVNS) has been demonstrated to lower blood pressure (BP) in rats without causing major side effects. This method might be adapted for the treatment of therapy-resistant hypertension in patients. Converting enzyme inhibitors (CEIs) are among the first drugs that are administered for arterial hypertension and prominently reduce BP primarily by interacting with the renin-angiotensin system of the kidneys. Beyond the reduction of BP, CEI have a positive effect on the survival rate after myocardial infarction; they reduce the rates of stroke and improve the neurohormonal status in heart-failure patients. If sVNS might be introduced as a therapy against resistant hypertension, patients will at least partially stay on their CEI medication. It is therefore the aim of this study to investigate the influence of the CEI enalapril on the haemodynamic and respiratory effects of sVNS. In 10 male Wistar rats, a polyimide-based multichannel-cuff-electrode was placed around the vagal nerve bundle to selectively stimulate the aortic depressor nerve fibres. Stimulation parameters were adapted to the thresholds of the individual animals and included repetition frequencies between 30 and 50 Hz, amplitudes of 0.5 to 1.5 mA and pulse widths between 0.4 ms and 1.0 ms. BP responses were detected with a microtip transducer in the left carotid artery, and electrocardiography was recorded with subcutaneous electrodes. After intravenous administration of enalapril (2 mg/kg bodyweight), the animals’ mean arterial blood pressures (MAPs) decreased significantly, while the heart rates (HRs) were not significantly influenced. The effects of sVNS on BP and HR were attenuated by enalapril but were still present. We conclude that sVNS can lower the MAP during enalapril treatment without relevant side effects. PMID:26766419

  20. Haemodynamic Responses to Selective Vagal Nerve Stimulation under Enalapril Medication in Rats.

    PubMed

    Gierthmuehlen, Mortimer; Stieglitz, Thomas; Zentner, Josef; Plachta, Dennis T T

    2016-01-01

    Selective vagal nerve stimulation (sVNS) has been demonstrated to lower blood pressure (BP) in rats without causing major side effects. This method might be adapted for the treatment of therapy-resistant hypertension in patients. Converting enzyme inhibitors (CEIs) are among the first drugs that are administered for arterial hypertension and prominently reduce BP primarily by interacting with the renin-angiotensin system of the kidneys. Beyond the reduction of BP, CEI have a positive effect on the survival rate after myocardial infarction; they reduce the rates of stroke and improve the neurohormonal status in heart-failure patients. If sVNS might be introduced as a therapy against resistant hypertension, patients will at least partially stay on their CEI medication. It is therefore the aim of this study to investigate the influence of the CEI enalapril on the haemodynamic and respiratory effects of sVNS. In 10 male Wistar rats, a polyimide-based multichannel-cuff-electrode was placed around the vagal nerve bundle to selectively stimulate the aortic depressor nerve fibres. Stimulation parameters were adapted to the thresholds of the individual animals and included repetition frequencies between 30 and 50 Hz, amplitudes of 0.5 to 1.5 mA and pulse widths between 0.4 ms and 1.0 ms. BP responses were detected with a microtip transducer in the left carotid artery, and electrocardiography was recorded with subcutaneous electrodes. After intravenous administration of enalapril (2 mg/kg bodyweight), the animals' mean arterial blood pressures (MAPs) decreased significantly, while the heart rates (HRs) were not significantly influenced. The effects of sVNS on BP and HR were attenuated by enalapril but were still present. We conclude that sVNS can lower the MAP during enalapril treatment without relevant side effects. PMID:26766419

  1. Fangchinoline inhibits glutamate release from rat cerebral cortex nerve terminals (synaptosomes).

    PubMed

    Lin, Tzu-Yu; Lu, Cheng-Wei; Tien, Lu-Tai; Chuang, Shu-Han; Wang, Yu-Ru; Chang, Wen-Hsuan; Wang, Su-Jane

    2009-07-01

    Fangchinoline, an active component of radix stephaniae tetrandrinea, has been shown to possess neuroprotective properties. It has been reported that excessive glutamate release has been proposed to be involved in the pathogenesis of several neurological diseases. The primary purpose of the present study was to investigate the effect of fangchinoline on glutamate release in rat cerebral cortex nerve terminals and to explore the possible mechanism. Fangchinoline inhibited the release of glutamate evoked by 4-aminopyridine (4-AP) in a concentration-dependent manner, and this phenomenon resulted from a reduction of vesicular exocytosis but not from an inhibition of Ca(2+)-independent efflux via glutamate transporter. Fangchinoline did not alter the resting synaptosomal membrane potential or 4-AP-mediated depolarization, but significantly reduced depolarization-induced increase in [Ca(2+)](C). Fangchinoline-mediated inhibition of glutamate release was significantly prevented by the N- and P/Q-type Ca(2+) channel blocker omega-conotoxin MVIIC, and by the PKC inhibitors, GF109203X and Ro318220. In addition, the glutamate release mediated by direct Ca(2+) entry with Ca(2+) ionophore (ionomycin) was unaffected by fangchinoline, which suggests that the inhibitory effect of fangchinoline is not due to directly interfering with the release process at some point subsequent to Ca(2+) influx. These results suggest that fangchinoline inhibits glutamate release from the rat cortical synaptosomes through the suppression of voltage-dependent Ca(2+) channel activity and subsequent reduces Ca(2+) entry into nerve terminals, rather than any upstream effect on nerve terminal excitability. This inhibition appears to involve the suppression of PKC signal transduction pathway. This finding may explain the neuroprotective effects of fangchinoline against neurotoxicity. PMID:19428795

  2. Tail arteries from chronically spinalized rats have potentiated responses to nerve stimulation in vitro

    PubMed Central

    Yeoh, Melanie; McLachlan, Elspeth M; Brock, James A

    2004-01-01

    Patients with severe spinal cord lesions that damage descending autonomic pathways generally have low resting arterial pressure but bladder or colon distension or unheeded injuries may elicit a life-threatening hypertensive episode. Such episodes (known as autonomic dysreflexia) are thought to result from the loss of descending baroreflex inhibition and/or plasticity within the spinal cord. However, it is not clear whether changes in the periphery contribute to the exaggerated reflex vasoconstriction. The effects of spinal transection at T7–8 on nerve- and agonist-evoked contractions of the rat tail artery were investigated in vitro. Isometric contractions of arterial segments were recorded and responses of arteries from spinalized animals (‘spinalized arteries’) and age-matched and sham-operated controls were compared. Two and eight weeks after transection, nerve stimulation at 0.1–10 Hz produced contractions of greater force and duration in spinalized arteries. At both stages, the α-adrenoceptor antagonists prazosin (10 nm) and idazoxan (0.1 μm) produced less blockade of nerve-evoked contraction in spinalized arteries. Two weeks after transection, spinalized arteries were supersensitive to the α1-adrenoceptor agonist phenylephrine, and the α2-adrenoceptor agonist, clonidine, but 8 weeks after transection, spinalized arteries were supersensitive only to clonidine. Contractions of spinalized arteries elicited by 60 mm K+ were larger and decayed more slowly at both stages. These findings demonstrate that spinal transection markedly increases nerve-evoked contractions and this can, in part, be accounted for by increased reactivity of the vascular smooth muscle to vasoconstrictor agents. This hyper-reactivity may contribute to the genesis of autonomic dysreflexia in patients. PMID:14766944

  3. The effects of huwentoxin-I on the voltage-gated sodium channels of rat hippocampal and cockroach dorsal unpaired median neurons.

    PubMed

    Wang, Meichi; Rong, Mingqiang; Xiao, Yucheng; Liang, Songping

    2012-03-01

    Huwentoxin-I (HWTX-I) is a 33-residue peptide isolated from the venom of Ornithoctonus huwena and could inhibit TTX-sensitive voltage-gated sodium channels and N-type calcium channels in mammalian dorsal root ganglion (DRG) neurons. However, the effects of HWTX-I on mammalian central neuronal and insect sodium channel subtypes remain unknown. In this study, we found that HWTX-I potently inhibited sodium channels in rat hippocampal and cockroach dorsal unpaired median (DUM) neurons with the IC(50) values of 66.1±5.2 and 4.80±0.58nM, respectively. Taken together with our previous work on DRG neurons (IC(50)≈55nM), the order of sodium channel sensitivity to HWTX-I inhibition was insect central DUM≫mammalian peripheral>mammalian central neurons. HWTX-I exhibited no effect on the steady-state activation and inactivation of sodium channels in rat hippocampal and cockroach DUM neurons. PMID:22094230

  4. The antiallodynic action of pregabalin may depend on the suppression of spinal neuronal hyperexcitability in rats with spared nerve injury

    PubMed Central

    Ding, Lei; Cai, Jie; Guo, Xiang-Yang; Meng, Xiu-Li; Xing, Guo-Gang

    2014-01-01

    BACKGROUND: Pregabalin (PGB) is a novel antiepileptic drug and is also used as a first-line medication for the treatment of neuropathic pain. However, the mechanisms of its analgesic effects remain largely unknown. OBJECTIVES: To elucidate the mechanisms underlying the antiallodynic action of PGB in rats with neuropathic pain. METHODS: In a rat model of neuropathic pain induced by spared nerve injury, mechanical allodynia, as a behavioural sign of neuropathic pain, was assessed by measuring 50% paw withdrawal threshold with von Frey filaments. Activities of dorsal horn wide dynamic range (WDR) neurons were examined by extracellular electrophysiological recording in vivo. RESULTS: Spinal administration of PGB exerted a significant antiallodynic effect and a prominent inhibitory effect on the hypersensitivity of dorsal horn WDR neurons in rats with spared nerve injury. CONCLUSION: The antiallodynic action of PGB is likely dependent on the suppression of WDR neuron hyperexcitability in rats with neuropathic pain. PMID:24851240

  5. Uterine autonomic nerve innervation plays a crucial role in regulating rat uterine mast cell functions during embryo implantation.

    PubMed

    Yuan, Xue-Jun; Huang, Li-Bo; Qiao, Hui-Li; Deng, Ze-Pei; Fa, Jing-Jing

    2009-12-01

    To explore the potential mechanism of how uterine innervations would affect the uterine mast cell (MC) population and functions during the periimplantation. We herein first examined the consequence of uterine neurectomy on embryo implantation events. We observed that amputation of autonomic nerves innervating the uterus led to on-time implantation failure in rats. Exploiting MC culture and ELISA approaches, we then further analyzed the effect of neurectomy on cellular histamine levels and its release from uterine MCs, to elucidate the relation of the autonomic nerves and local cellular immunity in the uterine during early pregnancy. We observed that disconnection of autonomic nerve innervation significantly increased the population of uterine MCs. Most interestingly, these increased number of uterine MCs in neuroectomized rats contained a much reduced cellular level of histamine. Our subsequent challenge experiments revealed that uterine MCs in nerve amputated rats exhibited enhanced histamine releasing rate in response to substance P and antiIgE, suggesting loss of nerve innervation in the uterus not only increases the population of uterine MCs, but also facilitates the release of histamine from MCs, thus subsequently interfere with the normal implantation process. Collectively, our findings provide a new line of evidence supporting the concept that immune-neuro-endocrine network plays important role during pregnancy establishment and maintenance. PMID:19765668

  6. Effects of culture supernatant from Lactobacillus pentosus strain S-PT84 on autonomic nerve activity in rats.

    PubMed

    Beppu, Yoshinori; Izumo, Takayuki; Horii, Yuko; Shen, Jiao; Fujisaki, Yoshiyuki; Nakashima, Toshihiro; Tsuruoka, Nobuo; Nagai, Katsuya

    2012-01-01

    Intestinal administration of various lactobacilli has been reported to affect autonomic neurotransmission, blood pressure, blood glucose, and body weight in rats, however, the mechanisms of action of the lactobacilli remain to be clarified. Therefore, the effect of the culture supernatant of Lactobacillus pentosus strain S-PT84 on the autonomic nerve activity in urethane-anesthetized rats was investigated. Intraduodenal injection of the low-molecular-weight (LMW) fraction (molecules less than 10,000 Da) of the S-PT84 culture supernatant elevated the brown adipose tissue sympathetic nerve activity and reduced the gastric vagal nerve activity. Moreover, intraoral administration of this LMW fraction increased the body temperature of rats above the interscapular brown adipose tissue. These results suggest that the LMW fraction of the S-PT84 culture supernatant affects the autonomic nerve activity and thermogenesis, and that the change in thermogenesis may be caused by the change in the sympathetic nerve activity of brown adipose tissue. PMID:22523286

  7. Thermographic evaluation of hind paw skin temperature and functional recovery of locomotion after sciatic nerve crush in rats

    PubMed Central

    Z. Sacharuk, Viviane; A. Lovatel, Gisele; Ilha, Jocemar; Marcuzzo, Simone; Severo do Pinho, Alexandre; L. Xavier, Léder; A. Zaro, Milton; Achaval, Matilde

    2011-01-01

    INTRODUCTION: Peripheral nerves are often damaged by direct mechanical injury, diseases, and tumors. The peripheral nerve injuries that result from these conditions can lead to a partial or complete loss of motor, sensory, and autonomic functions, which in turn are related to changes in skin temperature, in the involved segments of the body. The aim of this study was to evaluate the changes in hind paw skin temperature after sciatic nerve crush in rats in an attempt to determine whether changes in skin temperature correlate with the functional recovery of locomotion. METHODS: Wistar rats were divided into three groups: control (n = 7), sham (n = 25), and crush (n = 25). All groups were subjected to thermographic, functional, and histological assessments. RESULTS: ΔT in the crush group was different from the control and sham groups at the 1st, 3rd and 7rd postoperative days (p<0.05). The functional recovery from the crush group returned to normal values between the 3rd and 4th week post-injury, and morphological analysis of the nerve revealed incomplete regeneration at the 4th week after injury. DISCUSSION: This study is the first demonstration that sciatic nerve crush in rats induces an increase in hind paw skin temperature and that skin temperature changes do not correlate closely with functional recovery PMID:21876984

  8. Perinatal taurine exposure programs patterns of autonomic nerve activity responses to tooth pulp stimulation in adult male rats

    PubMed Central

    Khimsuksri, Sawita; Wyss, J. Michael; Thaeomor, Atcharaporn; Paphangkorakit, Jarin; Jirakulsomchok, Dusit; Roysommuti, Sanya

    2016-01-01

    Perinatal taurine excess or deficit influences adult health and disease, especially relative to the autonomic nervous system. This study tests the hypothesis that perinatal taurine exposure influences adult autonomic nervous system control of arterial pressure in response to acute electrical tooth pulp stimulation. Female Sprague-Dawley rats were fed normal rat chow with 3% β-alanine (taurine depletion, TD), 3% taurine (taurine supplementation, TS) or water alone (control, C) from conception to weaning. Their male offspring were fed normal rat chow and tap water throughout the experiment. At 8–10 weeks of age, blood chemistry, arterial pressure, heart rate and renal sympathetic nerve activity were measured in anesthetized rats. Age, body weight, mean arterial pressure, heart rate, plasma electrolytes, blood urea nitrogen, plasma creatinine and plasma cortisol were not significantly different among the three groups. Before tooth pulp stimulation, low (0.3–0.5 Hz) and high frequency (0.5–4.0 Hz) power spectral densities of arterial pressure were not significantly different among groups, while the power spectral densities of renal sympathetic nerve activity were significantly decreased in TD compared to control rats. Tooth pulp stimulation did not change arterial pressure, heart rate, renal sympathetic nerve and arterial pressure power spectral densities in the 0.3–4.0 Hz spectrum or renal sympathetic nerve firing rate in any group. In contrast, perinatal taurine imbalance disturbed very low frequency power spectral densities of both arterial pressure and renal sympathetic nerve activity (below 0.1 Hz), both before and after the tooth pulp stimulation. The power densities of TS were most sensitive to ganglionic blockade and central adrenergic inhibition, while those of TD were sensitive to both central and peripheral adrenergic inhibition. The present data indicate that perinatal taurine imbalance can lead to aberrant autonomic nervous system responses in

  9. Plate reader-based cell viability assays for glioprotection using primary rat optic nerve head astrocytes

    PubMed Central

    Kaja, Simon; Payne, Andrew J.; Naumchuk, Yuliya; Levy, Deborah; Zaidi, Danish H.; Altman, Alexa M.; Nawazish, Saba; Ghuman, Jasleen K.; Gerdes, Bryan C.; Moore, Mark A.; Koulen, Peter

    2015-01-01

    Optic nerve head astrocytes (ONHAs) are the major glia cell type in the non-myelinated optic nerve head where they contribute critically to extracellular matrix synthesis during development and throughout life. In glaucoma, and in related disorders affecting the optic nerve and the optic nerve head, pathological changes include altered astrocyte gene and protein expression resulting in their activation and extracellular matrix remodeling. ONHAs are highly sensitive to mechanical and oxidative stress resulting in the initiation of axon damage early during pathogenesis. Furthermore, ONHAs are crucial for the maintenance of retinal ganglion cell physiology and function. Therefore, glioprotective strategies with the goal to preserve and/or restore the structural and functional viability of ONHA in order to slow glaucoma and related pathologies are of high clinical relevance. Herein, we describe the development of standardized methods that will allow for the systematic advancement of such glioprotective strategies. These include isolation, purification and culture of primary adult rat ONHAs, optimized immunocytochemical protocols for cell type validation, as well as plate reader-based assays determining cellular viability, proliferation and the intracellular redox state. We validated and standardized our protocols by performing a glioprotection study using primary ONHAs. Specifically, we measured protection against exogenously-applied oxidative stress using tert-butylhydroperoxide (tBHP) as a model of disease-mediated oxidative stress in the retina and optic nerve head by the prototypic antioxidant, 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid (Trolox). Levels of oxidative stress were increased in the response to exogenously applied tBHP and were assessed by 6-carboxy-2′, 7′ dichlorodihydrofluorescein diacetate (DCFDA) fluorescence. Normalized DCFDA fluorescence showed a maximal 5.1-fold increase; the half-maximal effect (EC50) for tBHP was 212 ± 25

  10. Effect of exercise on the expression of nerve growth factor in the spinal cord of rats with induced osteoarthritis.

    PubMed

    Park, Soo-Jin; Yong, Min-Sik; Na, Sang-Su

    2015-08-01

    [Purpose] We examined the impact of exercise on the expression pattern of nerve growth factor in the spinal cord of rats with induced osteoarthritis of the knee joint. [Subjects and Methods] To produce monosodium iodoacetate-induced arthritis, rats were administered 3 mg/50 µL monosodium iodoacetate through the interarticular space of the right knee. The animals were randomly divided into four groups: rats sacrificed 3 weeks after 0.9% saline solution injection (shame group, n = 10), rats sacrificed 3 weeks after monosodium iodoacetate injection (control group, n = 10), rats with 4 weeks rest from 3 weeks after monosodium iodoacetate injection (no exercise group, n = 10), and rats with 4 weeks treadmill training from 3 weeks after monosodium iodoacetate injection (exercise group, n = 10). Serial coronal sections of the lumbar spine were cut and processed for immunohistochemistry. [Results] The expression of nerve growth factor was significantly increased in the EG compared with the SG, CG, and NEG. [Conclusion] Increased nerve growth factor expression in the spinal cord due to exercise-induced stimulation can be effective in treating chronic pain. Such treatment will contribute not only to improving the joint function of patients with chronic pain but also their quality of life. PMID:26357438

  11. Peripheral nerve reconstruction with epsilon-caprolactone conduits seeded with vasoactive intestinal peptide gene-transfected mesenchymal stem cells in a rat model

    NASA Astrophysics Data System (ADS)

    Hernández-Cortés, P.; Toledo-Romero, M. A.; Delgado, M.; Sánchez-González, C. E.; Martin, F.; Galindo-Moreno, P.; O'Valle, F.

    2014-08-01

    Objective. Attempts have been made to improve nerve conduits in peripheral nerve reconstruction. We investigated the potential therapeutic effect of a vasoactive intestinal peptide (VIP), a neuropeptide with neuroprotective, trophic and developmental regulatory actions, in peripheral nerve regeneration in a severe model of nerve injury that was repaired with nerve conduits. Approach. The sciatic nerve of each male Wistar rat was transected unilaterally at 10 mm and then repaired with Dl-lactic-ɛ-caprolactone conduits. The rats were treated locally with saline, with the VIP, with adipose-derived mesenchymal stem cells (ASCs) or with ASCs that were transduced with the VIP-expressing lentivirus. The rats with the transected nerve, with no repairs, were used as untreated controls. At 12 weeks post-surgery, we assessed their limb function by measuring the ankle stance angle and the percentage of their muscle mass reduction, and we evaluated the histopathology, immunohistochemistry and morphometry of the myelinated fibers. Main results. The rats that received a single injection of VIP-expressing ASCs showed a significant functional recovery in the ankle stance angle (p = 0.049) and a higher number of myelinated fibers in the middle and distal segments of the operated nerve versus the other groups (p = 0.046). Significance. These results suggest that utilization of a cellular substrate, plus a VIP source, is a promising method for enhancing nerve regeneration using Dl-lactic-ɛ-caprolactone conduits and that this method represents a potential useful clinical approach to repairing peripheral nerve damage.

  12. FK506-loaded chitosan conduit promotes the regeneration of injured sciatic nerves in the rat through the upregulation of brain-derived neurotrophic factor and TrkB.

    PubMed

    Zhao, Jia; Zheng, Xifu; Fu, Chongyang; Qu, Wei; Wei, Guoqiang; Zhang, Weiguo

    2014-09-15

    FK506 has been shown to exert neurotrophic and neuroprotective effects, but its long-term application for nerve regeneration is limited. This study evaluated the potential application of a novel FK506-loaded chitosan conduit for peripheral nerve repair, and explored the underlying mechanism. A sciatic nerve injury model was created in male Wistar rats, which were then randomly divided into three treatment groups (n=40, each): chitosan-only, chitosan+FK506 injection, and FK506-loaded chitosan. We found significant recovery of normal morphology of sciatic nerves and higher density of myelinated nerve fibers in rats treated with FK506-loaded chitosan. Similarly, the total number of myelinated nerve fibers, myelin sheath thickness, and axon diameters were significantly higher in this group compared with the others, and the compound muscle action potentials and motor nerve conduction velocity values of sciatic nerves were significantly higher. BDNF and TrkB levels in motor neurons were highest in rats treated with FK506-loaded chitosan. In conclusion, FK506-loaded chitosan promoted peripheral nerve repair and regeneration in a rat model of sciatic nerve injury. These effects are correlated with increased BDNF and TrkB expression in motor neurons. PMID:24954089

  13. Essential oil of Croton zehntneri and its main constituent anethole block excitability of rat peripheral nerve.

    PubMed

    da Silva-Alves, Kerly Shamyra; Ferreira-da-Silva, Francisco Walber; Coelho-de-Souza, Andrelina Noronha; Albuquerque, Aline Alice Cavalcante; do Vale, Otoni Cardoso; Leal-Cardoso, José Henrique

    2015-03-01

    Croton zehntneri is an aromatic plant native to Northeast Brazil and employed by local people to treat various diseases. The leaves of this plant have a rich content of essential oil. The essential oil of C. zehntneri samples, with anethole as the major constituent and anethole itself, have been reported to have several pharmacological activities such as antispasmodic, cardiovascular, and gastroprotective effects and inducing the blockade of neuromuscular transmission and antinociception. Since several works have demonstrated that essential oils and their constituents block cell excitability and in view of the multiple effects of C. zehntneri essential oil and anethole on biological tissues, we undertook this investigation aiming to characterize and compare the effects of this essential oil and its major constituent on nerve excitability. Sciatic nerves of Wistar rats were used. They were mounted in a moist chamber, and evoked compound action potentials were recorded. Nerves were exposed in vitro to the essential oil of C. zehntneri and anethole (0.1-1 mg/mL) up to 180 min, and alterations in excitability (rheobase and chronaxie) and conductibility (peak-to-peak amplitude and conduction velocity) parameters of the compound action potentials were evaluated. The essential oil of C. zehntneri and anethole blocked, in a concentration-dependent manner with similar pharmacological potencies (IC50: 0.32 ± 0.07 and 0.22 ± 0.11 mg/mL, respectively), rat sciatic nerve compound action potentials. Strength-duration curves for both agents were shifted upward and to the right compared to the control curve, and the rheobase and chronaxie were increased following essential oil and anethole exposure. The time courses of the essential oil of C. zehntneri and anethole effects on peak-to-peak amplitude of compound action potentials followed an exponential decay and reached a steady state. The essential oil of C. zehntneri and anethole caused a similar reduction in

  14. Current-clamp analysis of a time-dependent rectification in rat optic nerve.

    PubMed Central

    Eng, D L; Gordon, T R; Kocsis, J D; Waxman, S G

    1990-01-01

    1. Rat optic nerves were studied using intra-axonal and whole-nerve recording techniques in a sucrose-gap chamber. Constant-current pulses were applied across the outer compartments of the chamber to achieve a current clamp. 2. The nerves displayed a prominent time-dependent conductance increase elicited by a hyperpolarizing constant-current pulse, as evidenced by a relaxation or 'sag' in membrane potential towards resting potential. The inward current began at about 80 ms and reached a steady level over the next 100-200 ms. Its magnitude progressively increased with increasing levels of hyperpolarization. 3. The inward current elicited by hyperpolarization was reduced, but not abolished, when Na+ was reduced from the normal bath concentration of 151 mM to 0 mM. In Na(+)-free solutions the bath K+ concentration, [K+]o, was varied between 0 and 5 mM; the inward current was greatest when [K+]o was 5 mM and was abolished when [K+]o was zero. 4. The inward current was not abolished by tetrodotoxin (TTX), tetraethylammonium (TEA) or 4-aminopyridine (4-AP) suggesting that conventional voltage-dependent sodium and potassium channels do not underlie the time-dependent conductance increase. Low concentrations of Cs+ completely blocked the inward current, and Ba2+ induced a partial block. External application of divalent cations (Cd2+ and Mg2+) did not block the inward current. These properties are similar to the inwardly rectifying conductance observed in a central nervous system neurone. 5. Stimulus-response curves obtained during the hyperpolarization pulse, before and during the conductance increase, indicate that excitability is increased during the conductance increase. This along with the intra-axonal recordings demonstrates that the origin of the increased conductance is axonal and not glial. 6. It is concluded that central nervous system myelinated fibres in rat optic nerve display a prominent time-dependent conductance increase in response to hyperpolarization that

  15. Near-infrared reflectance spectroscopy as a novel method to detect demyelination in rat sciatic nerve in vivo

    NASA Astrophysics Data System (ADS)

    Radhakrishnan, Harsha; Senapati, Arun; Peng, Yuan Bo; Kashyap, Dheerendra; Liu, Hanli

    2005-04-01

    This study was done to use near infrared (NIR) spectroscopy to bring out differences in the anatomical substructures in the rat spinal cord and further to differentiate scattering between demyelinated and normal sciatic nerves in rat models, thereby exploring a new methodology to localize MS (multiple Sclerosis) lesions in vivo for animal studies. The experimental setup consisted of a tungsten light source, CCD array spectrometer, and bifurcated optical fibers for light delivery and detection of back scattered light from tissue. The measurement system was calibrated with reflectance standard. The spinal cord of 14 rats was exposed by laminectomy, and the measurements were taken on 8 points at intervals of 1 mm on the right and left lumbar-sacral regions and the central blood vessel. For measurements on the sciatic nerve, the spinal nerves of 84 rats were ligated according to the Chung Model. Measurements were taken on five points on both the ligated and the control nerve side after 1, 4, 7 and 14 days. The reduced scattering coefficient, μs', was found to be higher in the lumbar-sacral regions (34.17 +/- 2.05 cm-1) than that near the central blood vessel (19.9 +/- 3.8 cm-1). Statistically, there was significant difference in scattering between the control side and the ligated side on postoperative days 4, 7, and 14. This study shows a promising diagnostic value in the future for monitoring of demyelinated CNS (central nervous system) diseases, like Multiple Sclerosis.

  16. Functional and morphological assessment of a standardized rat sciatic nerve crush injury with a non-serrated clamp.

    PubMed

    Varejão, Artur S P; Cabrita, António M; Meek, Marcel F; Bulas-Cruz, José; Melo-Pinto, Pedro; Raimondo, Stefania; Geuna, Stefano; Giacobini-Robecchi, Maria G

    2004-11-01

    Peripheral nerve researchers frequently use the rat sciatic nerve crush as a model for axonotmesis. Unfortunately, studies from various research groups report results from different crush techniques and by using a variety of evaluation tools, making comparisons between studies difficult. The purpose of this investigation was to determine the sequence of functional and morphologic changes after an acute sciatic nerve crush injury with a non-serrated clamp, giving a final standardized pressure of p = 9 MPa. Functional recovery was evaluated using the sciatic functional index (SFI), the extensor postural thrust (EPT) and the withdrawal reflex latency (WRL), before injury, and then at weekly intervals until week 8 postoperatively. The rats were also evaluated preoperatively and at weeks 2, 4, and 8 by ankle kinematics, toe out angle (TOA), and gait-stance duration. In addition, the motor nerve conduction velocity (MNCV) and the gastrocnemius-soleus weight parameters were measured just before euthanasia. Finally, structural, ultrastructural and histomorphometric analyses were carried out on regenerated nerve fibers. At 8 weeks after the crush injury, a full functional recovery was predicted by SFI, EPT, TOA, and gait-stance duration, while all the other parameters were still recovering their original values. On the other hand, only two of the histomorphometric parameters of regenerated nerve fibers, namely myelin thickness/axon diameter ratio and fiber/axon diameter ratio, returned to normal values while all other parameters were significantly different from normal values. The employment of traditional methods of functional evaluation in conjunction with the modern techniques of computerized analysis of gait and histomorphometric analysis should thus be recommended for an overall assessment of recovery in the rat sciatic nerve crush model. PMID:15684656

  17. Synergistic effects of low-level laser and mesenchymal stem cells on functional recovery in rats with crushed sciatic nerves.

    PubMed

    Yang, Chen-Chia; Wang, John; Chen, Shyh-Chang; Hsieh, Yueh-Ling

    2016-02-01

    Transplantation of mesenchymal stem cells (MSCs) has been proposed to exert beneficial effects on peripheral nerve regeneration after a peripheral nerve injury, but the functional recovery in the denervated limb is still limited. In this study, we used low-level laser therapy (LLLT) as an adjunct therapy for MSC transplantation on the functional recovery of crushed sciatic nerve in rats. Peripheral nerve injury was induced in 48 Sprague-Dawley rats by crushing the unilateral sciatic nerve, using a vessel clamp. The animals with crushed injury were randomly divided into four groups: control group, with no treatment; MSC group, treated with MSC alone; LLLT group, treated with LLLT alone; and MSCLLLT group, treated with a combination of MSC and LLLT. The sciatic function index (SFI), vertical activity of locomotion (VA) and ankle angle (AA) of rats were examined for functional assessments after treatment. Electrophysiological, morphological and S100 immunohistochemical studies were also conducted. The MSCLLLT group showed a greater recovery in SFI, VA and AA, with significant difference from MSC, LLLT and control groups (p < 0.05). Moreover, markedly enhanced electrophysiological function and expression of S100 immunoreactivity, as well as fewer inflammatory cells and less vacuole formation were also demonstrated after nerve crush injury in the MSCLLLT group when compared with the groups receiving a single treatment (p < 0.05). MSC transplantation combined with LLLT could achieve better results in functional recovery than a conventional treatment of MSC or LLLT alone. LLLT has a synergistic effect in providing greater functional recovery with MSC transplantation after nerve crush injury. PMID:23468370

  18. Spatial distribution of nerve processes and β-adrenoreceptors in the rat atrioventricular node

    PubMed Central

    PETRECCA, KEVIN; SHRIER, ALVIN

    1998-01-01

    Atrioventricular (AV) nodal conduction time is known to be modulated by the autonomic nervous system. The presence of numerous parasympathetic and sympathetic nerve fibres in association with conduction tissue in the heart is well authenticated. In this study, confocal microscopy was used to image the distribution of antibodies directed against the general neuronal marker PGP 9.5, tyrosine hydroxylase (TH), vasoactive intestinal peptide (VIP), calcitonin gene-related peptide (CGRP) and β1 and β2-adrenoreceptors. Serial 12 μm sections of fresh frozen tissue taken from the frontal plane of the rat atrioventricular node, His bundle and bundle branches were processed for histology, acetylcholinesterase (AChE) activity and immunohistochemistry. It was found that the AV and ventricular conduction systems were more densely innervated than the atrial and ventricular myocardium as revealed by PGP 9.5 immunoreactivity. Furthermore, the transitional cell region was more densely innervated than the midnodal cell region, while spatial distribution of total innervation was uniform throughout all AV nodal regions. AChE-reactive nerve processes were found throughout the AV and ventricular conduction systems, the spatial distribution of which was nonuniform exhibiting a paucity of AChE-reactive nerve processes in the central midnodal cell region and a preponderance in the circumferential transitional cell region. TH-immunoreactivity was uniformly distributed throughout the AV and ventricular conduction systems including the central midnodal and circumferential transitional cell regions. β1-adrenoreceptors were found throughout the AV and ventricular conduction systems with a preponderance in the circumferential transitional cell region. β2-adrenoreceptors were localised predominantly in AV and ventricular conduction systems with a paucity of expression in the circumferential transitional cell region. These results demonstrate that the overall uniform distribution of total

  19. Assessment of Neuroprotective Effects of Local Administration of 17- Beta- Estradiol on Peripheral Nerve Regeneration in Ovariectomized Female Rats

    PubMed Central

    Nobakhti-Afshar, Ahmadreza; Najafpour, Alireza; Mohammadi, Rahim; Zarei, Leila

    2016-01-01

    Objective: To assess the neuroprotective effects of local administration of 17- beta- estradiol on nerve regeneration. Methods: Sixty female Wistar rats were overiectomized and divided into four experimental groups (n = 15), randomly: In autograft group a segment of sciatic nerve was transected and re-implanted reversely. In sham-surgery group sciatic nerve was exposed and manipulated. In transected group left sciatic nerve was transected and stumps were fixed in adjacent muscle. In treatment group defect was bridged using a silicon conduit filled with 10 µL (0.1 mg/mL) 17- beta- estradiol. Each group was subdivided into four subgroups of five animals each and nerve fibers were studied in a 12-week period. Results: Behavioral, functional, biomechanical, electrophysiological and gastrocnemius muscle mass findings and morphometric indices confirmed faster recovery of regenerated axons in treatment group than in other groups (p<0.05). Immunohistochemical reactions to S-100 in treatment group were more positive than that in other groups. Conclusion: Local administration of 17-beta-estradiol improved functional recovery and morphometric indices of sciatic nerve. It could have clinical implications for the surgical management of patients after facial nerve transection. PMID:27540548

  20. Trigeminal nerve injury induced thrombospondin-4 upregulation contributes to orofacial neuropathic pain states in a rat model

    PubMed Central

    Li, Kang-Wu; Kim, Doo-Sik; Zaucke, Frank; Luo, Z. David

    2013-01-01

    Background Injury to the trigeminal nerve often results in the development of chronic pain states including tactile allodynia, or hypersensitivity to light touch, in orofacial area, but its underlying mechanisms are poorly understood. Peripheral nerve injury has been shown to cause upregulation of thrombospondin-4 (TSP4) in dorsal spinal cord that correlates with neuropathic pain development. In this study, we examined whether injury-induced TSP4 is critical in mediating orofacial pain development in a rat model of chronic constriction injury to the infraorbital nerve (CCI-ION). Methods Orofacial sensitivity to mechanical stimulation was examined in a unilateral infraorbital nerve ligation rat model. The levels of TSP4 in trigeminal ganglia and associated spinal subnucleus caudalis and C1/C2 spinal cord (Vc/C2) from injured rats were examined at time points correlating with the initiation and peak orofacial hypersensitivity. TSP4 antisense and mismatch oligodeoxynucleotides were intrathecally injected into injured rats to see if antisense oligodeoxynucleotide treatment could reverse injury-induced TSP4 upregulation and orofacial behavioral hypersensitivity. Results Our data indicated that trigeminal nerve injury induced TSP4 upregulation in Vc/C2 at a time point correlated with orofacial tactile allodynia. In addition, intrathecal treatment with TSP4 antisense, but not mismatch, oligodeoxynucleotides blocked both injury-induced TSP4 upregulation in Vc/C2 and behavioral hypersensitivity. Conclusions Our data support that infraorbital nerve injury leads to TSP4 upregulation in trigeminal spinal complex that contributes to orofacial neuropathic pain states. Blocking this pathway may provide an alternative approach in management of orofacial neuropathic pain states. PMID:24019258

  1. Endoneurial pathology of the needlestick-nerve-injury model of Complex Regional Pain Syndrome, including rats with and without pain behaviors

    PubMed Central

    Klein, Max M.; Lee, Jeung Woon; Siegel, Sandra M.; Downs, Heather M.; Oaklander, Anne Louise

    2011-01-01

    Current rodent models of neuropathic pain produce pain hypersensitivity in almost all lesioned animals and not all identified experimental effects are pain specific. 18G needlestick-nerve-injury (NNI) to one tibial nerve of outbred Sprague-Dawley rats models the phenotype of Complex Regional Pain Syndrome (CRPS), a post-traumatic neuropathic pain syndrome, leaving roughly half of NNI rats with hyperalgesia. We compared endoneurial data from these divergent endophenotypes searching for pathological changes specifically associated with pain-behaviors. Tibial, sural, and common sciatic nerves from 12 NNI rats plus 10 nerves from sham-operated controls were removed 14 days post-surgery for morphometric analysis. PGP9.5+ unmyelinated-fibers were quantitated in plantar hindpaw skin. Distal tibial nerves of NNI rats had endoneurial edema, 30% fewer axons, twice as many mast cells, and thicker blood-vessel walls than uninjured tibial nerves. However the only significant difference between nerves from hyperalgesic versus non-hyperalgesic NNI rats was greater endoneurial edema in hyperalgesic rats (p < 0.01). We also discovered significant axonal losses in uninjured ipsilateral sural nerves of NNI rats, demonstrating spread of neuropathy to nearby nerves formerly thought spared. Tibial and sural nerves contralateral to NNI had significant changes in endoneurial bloodvessels. Similar pathological changes have been identified in CRPS-I patients. The current findings suggest that severity of endoneurial vasculopathy and inflammation may correlate better with neuropathic pain behaviors than degree of axonal loss. Spread of pathological changes to nearby ipsilateral and contralesional nerves might potentially contribute to extraterritorial pain in CRPS. PMID:21676634

  2. Vagus Nerve Stimulation Improves Cardiac Function by Preventing Mitochondrial Dysfunction in Obese-Insulin Resistant Rats

    PubMed Central

    Samniang, Bencharunan; Shinlapawittayatorn, Krekwit; Chunchai, Titikorn; Pongkan, Wanpitak; Kumfu, Sirinart; Chattipakorn, Siriporn C.; KenKnight, Bruce H.; Chattipakorn, Nipon

    2016-01-01

    Long-term high-fat diet (HFD) consumption leads to not only obese-insulin resistance, but also impaired left ventricular (LV) function. Vagus nerve stimulation (VNS) has been shown to exert cardioprotection. However, its effects on the heart and metabolic parameters under obese-insulin resistant condition is not known. We determined the effects of VNS on metabolic parameters, heart rate variability (HRV) and LV function in obese-insulin resistant rats. Male Wistar rats were fed with HFD for 12 weeks, and were randomly divided into sham and VNS groups. VNS was applied for the next 12 weeks. Echocardiography, blood pressure and HRV were examined. Blood samples were collected for metabolic parameters. At the end, the heart was removed for determination of apoptosis, inflammation, oxidative stress, and cardiac mitochondrial function. VNS for 12 weeks significantly decreased plasma insulin, HOMA index, total cholesterol, triglyceride, LDL and visceral fat. Serum adiponectin was significantly increased in the VNS group. VNS also significantly decreased blood pressure, improved HRV and LV function, decreased cardiac MDA, TNF-α and Bax levels, and improved cardiac mitochondrial function. VNS improves metabolic and hemodynamic parameters, and the LV function via its ability against apoptosis, inflammation and oxidative stress, and preserved cardiac mitochondrial function in obese-insulin resistant rats. PMID:26830020

  3. Patterns of Phrenic Nerve Discharge after Complete High Cervical Spinal Cord Injury in the Decerebrate Rat.

    PubMed

    Ghali, Michael George Zaki; Marchenko, Vitaliy

    2016-06-15

    Studies conducted since the second half of the 19th century have revealed spontaneous as well as pharmacologically induced phasic/rhythmic discharge in spinal respiratory motor outputs of cats, dogs, rabbits, and neonatal rats following high cervical transection (Tx). The extent to which these various studies validate the existence of a true spinal respiratory rhythm generator remains debated. In this set of studies, we seek to characterize patterns of spontaneous phasic/rhythmic, asphyxia-induced, and pharmacologically induced activity occurring in phrenic nerve (PhN) discharge after complete high cervical (C1-C2) spinal cord transection. Experiments were performed on 20 unanesthetized decerebrate Sprague-Dawley adult male rats. Patterns of spontaneous activity after spinalization included tonic, phasic, slow oscillatory, and long-lasting tonic discharges. Topical application of antagonists of GABAA and glycine receptors to C1- and C2- spinal segments induced left-right synchronized phasic decrementing activity in PhN discharge that was abolished by an additional C2Tx. Asphyxia elicited increases in tonic activity and left-right synchronized gasp-like bursts in PhN discharge, demonstrating the presence of spinal circuits that may underlie a spinal gasping-like mechanism. We conclude that intrinsic slow oscillators and a phasic burst/rhythm generator exist in the spinal cord of the adult rat. If present in humans, this mechanism may be exploited to recover respiratory function in patients sustaining severe spinal cord injury. PMID:26239508

  4. Methylcobalamin increases Erk1/2 and Akt activities through the methylation cycle and promotes nerve regeneration in a rat sciatic nerve injury model.

    PubMed

    Okada, Kiyoshi; Tanaka, Hiroyuki; Temporin, Ko; Okamoto, Michio; Kuroda, Yusuke; Moritomo, Hisao; Murase, Tsuyoshi; Yoshikawa, Hideki

    2010-04-01

    Methylcobalamin is a vitamin B12 analog and is necessary for the maintenance of the nervous system. Although some previous studies have referred to the effects of methylcobalamin on neurons, the precise mechanism of this effect remains obscure. Here we show that methylcobalamin at concentrations above 100 nM promotes neurite outgrowth and neuronal survival and that these effects are mediated by the methylation cycle, a metabolic pathway involving methylation reactions. We also demonstrate that methylcobalamin increases Erk1/2 and Akt activities through the methylation cycle. In a rat sciatic nerve injury model, continuous administration of high doses of methylcobalamin improves nerve regeneration and functional recovery. Therefore, methylcobalamin may provide the basis for better treatments of nervous disorders through effective systemic or local delivery of high doses of methylcobalamin to target organs. PMID:20045411

  5. Comparison of two electrophysiological methods for the assessment of progress in a rat model of nerve repair.

    PubMed

    Han, Dong; Lu, Jiuzhou; Xu, Lei; Xu, Jianguang

    2015-01-01

    There are 2 critical steps in neural regeneration: nerve fibres successfully crossing the suture and restoration of neuromuscular transmission. For the second step, the compound muscle action potential (CMAP) is the standard electrophysiological technique used to assess regeneration, but it is difficult to detect changes in the CMAP during early regeneration after nerve repair. There is a need for better, noninvasive quantitative electrophysiological techniques to assess regeneration in an earlier stage after nerve repair. In this study, we utilized 2 measures, CMAP and single-fibre electromyography (SFEMG), in a rat model of nerve repair. The model was generated by separating the sciatic nerve of the rat hindlimb from the tibial nerve in Sprague-Dawley rats. CMAP and SFEMG were measured in each rat at 1, 2, 3, 4, and 6 weeks after the operation. The muscle weight was measured and both the general structure of the muscle and the changes in muscle atrophy were examined using haematoxylin and eosin staining protocols. The nerve electrophysiological data could be detected at 2 weeks after surgery initially and more data could be collected with passing time. During the period ranging from 2 to 4 weeks after surgery, parameters of SFEMG recordings changed significantly while the CMAP amplitude did not increase until 6 weeks after surgery. While the fibre density (FD) at 2 weeks after surgery was 0.27 ± 0.31, there was a significant increase at 3 weeks relative to 2 weeks (P < 0.01), and the FD increased further at 4 weeks (P < 0.01). The action potential mean consecutive difference (MCD) was significantly higher (60.50 ± 3.53 μs) in the second week relative to the third week (41.12 ± 5.08 μs) after the operation. The results indicated that SFEMG was more sensitive than CMAP amplitudes in detecting neuromuscular transmission after nerve repair. The findings of nerve electrophysiological experiments were consistent with the observed degree of muscle recovery. The

  6. Calpain 3 Expression Pattern during Gastrocnemius Muscle Atrophy and Regeneration Following Sciatic Nerve Injury in Rats

    PubMed Central

    Wu, Ronghua; Yan, Yingying; Yao, Jian; Liu, Yan; Zhao, Jianmei; Liu, Mei

    2015-01-01

    Calpain 3 (CAPN3), also known as p94, is a skeletal muscle-specific member of the calpain family that is involved in muscular dystrophy; however, the roles of CAPN3 in muscular atrophy and regeneration are yet to be understood. In the present study, we attempted to explain the effect of CAPN3 in muscle atrophy by evaluating CAPN3 expression in rat gastrocnemius muscle following reversible sciatic nerve injury. After nerve injury, the wet weight ratio and cross sectional area (CSA) of gastrocnemius muscle were decreased gradually from 1–14 days and then recovery from 14–28 days. The active form of CAPN3 (~62 kDa) protein decreased slightly on day 3 and then increased from day 7 to 14 before a decrease from day 14 to 28. The result of linear correlation analysis showed that expression of the active CAPN3 protein level was negatively correlated with muscle wet weight ratio. CAPN3 knockdown by short interfering RNA (siRNA) injection improved muscle recovery on days 7 and 14 after injury as compared to that observed with control siRNA treatment. Depletion of CAPN3 gene expression could promote myoblast differentiation in L6 cells. Based on these findings, we conclude that the expression pattern of the active CAPN3 protein is linked to muscle atrophy and regeneration following denervation: its upregulation during early stages may promote satellite cell renewal by inhibiting differentiation, whereas in later stages, CAPN3 expression may be downregulated to stimulate myogenic differentiation and enhance recovery. These results provide a novel mechanistic insight into the role of CAPN3 protein in muscle regeneration after peripheral nerve injury. PMID:26569227

  7. The Impact of Different Degrees of Injured C7 Nerve Transfer: An Experimental Rat Study

    PubMed Central

    Tzou, Chieh-Han John; Chang, Tommy Nai-Jen; Lu, Johnny Chuieng-Yi

    2014-01-01

    Background: Ipsilateral C7 nerve transfer is an available procedure in C5C6 2-root avulsion injury of the brachial plexus. However, concomitant injury of a normal-looking C7 cannot be ruled out. The efficiency of a concomitant injury of C7 transfer was investigated. Methods: Forty-two Sprague-Dawley rats were randomly assigned to 5 groups. They all underwent a 2-stage procedure. In the first stage from dorsal spine approach, left C5 and C6 roots were avulsed and C7 was crushed with jeweler’s forceps with different degrees: group A (n = 6), C7 not injured; group B (n = 10), C7 crushed for 10 seconds; group C (n = 10), C7 crushed for 30 seconds; group D (n = 10), C7 doubly crushed for 60 seconds; and group E (n = 6), C7 transected and not repaired. Four weeks later in the second stage, the C7 was reexplored via volar approach, transected, and coapted to the musculocutaneous nerve. At 12 weeks following the nerve transfer, functional outcomes were assessed. Results: Grooming test, muscle weight, electromyography, and muscle tetanic contraction force all showed that the biceps muscles were significantly worse in group C (moderate crush) and group D (severe crush). Group B (mild crush) and group A (uninjured) showed no difference. Group E (C7 cut and not repaired) was the worst. Conclusions: An injured but grossly normal-looking ipsilateral C7 can be used as a motor source but with variable results. The result is directly proportional to the severity of injury, potentially implying that better results will be achieved when longer regeneration time is allowed. PMID:25426347

  8. Episodic phrenic-inhibitory vagus nerve stimulation paradoxically induces phrenic long-term facilitation in rats

    PubMed Central

    Zhang, Yi; McGuire, Michelle; White, David P; Ling, Liming

    2003-01-01

    All respiratory long-term facilitation (LTF) is induced by inspiratory-excitatory stimulation, suggesting that LTF needs inspiratory augmentation and is the result of a Hebbian mechanism (coincident pre- and post-synaptic activity strengthens synapses). The present study examined the long-term effects of episodic inspiratory-inhibitory vagus nerve stimulation (VNS) on phrenic nerve activity. We hypothesized that episodic VNS would induce phrenic long-term depression. The results are compared with those obtained following serotonin receptor antagonism or episodic carotid sinus nerve stimulation (CSNS). Integrated phrenic neurograms were measured before, during and after three episodes of 5 min VNS (50 Hz, 0.1 ms), each separated by a 5 min interval, at a low (˜50 μA), medium (˜200 μA) or high (˜500 μA) stimulus intensity in anaesthetized, vagotomized, neuromuscularly blocked and artificially ventilated rats. Medium- and high-intensity VNS eliminated rhythmic phrenic activity during VNS, while low-intensity VNS only reduced phrenic burst frequency. At 60 min post-VNS, phrenic amplitude was higher than baseline (35 ± 5 % above baseline, mean ± S.E.M., P < 0.05) in the high-intensity group but not in the low- (−4 ± 4 %) or medium-intensity groups (−10 ± 15 %), or in the high-intensity with methysergide group (4 mg kg−1, I.P.) (−11 ± 5 %). These data, which are inconsistent with our hypothesis, indicate that phrenic-inhibitory VNS induces a serotonin-dependent phrenic LTF similar to that induced by phrenic-excitatory CSNS (33 ± 7 %) and may require activation of high-threshold afferent fibres. These data also suggest that the synapses on phrenic motoneurons do not use the Hebbian mechanism in this LTF, as these motoneurons were suppressed during VNS. PMID:12872010

  9. Effects of natural free radical scavengers on peripheral nerve and neurovascular function in diabetic rats.

    PubMed

    Cotter, M A; Love, A; Watt, M J; Cameron, N E; Dines, K C

    1995-11-01

    Increased generation of reactive oxygen species, coupled with impaired endogenous scavenging mechanisms, plays a prominent role in the aetiology of neurovascular abnormalities in experimental diabetes mellitus. We examined the efficacy of the natural anti-oxidants vitamins C, E and beta-carotene in preventing nerve conduction and nutritive blood flow deficits in streptozotocin-diabetic rats. One month of diabetes caused a 19.1% reduction in sciatic motor conduction velocity (p < 0.001). This was approximately prevented 80-90% by high-dose (1000 mg.kg-1.day-1) vitamin E and beta-carotene treatments (p < 0.001). Vitamin C had lesser effects; the maximum protection found for motor conduction velocity was 36% using a dose of 150 mg.kg-1.day-1 (p < 0.001). High dose (500 mg.kg-1.day-1 (p < 0.001). High dose (500 mg.kg-1.day-1) vitamin C had a lesser effect on conduction than intermediate doses. Joint vitamin C and lower dose (500 mg.kg-1.day-1) vitamin E treatment had a predominantly additive preventive effect against nerve dysfunction. Resistance to hypoxic conduction failure for sciatic nerve in vitro was markedly increased by diabetes and this remained relatively unaffected by treatment. Sciatic nutritive endoneurial blood flow, measured using microelectrode polarography and hydrogen clearance, was reduced 46.1% by 1 month of diabetes (p < 0.001). This was prevented to the extent of 87%, 36% and 98% by vitamins E, C and beta-carotene, respectively (p < 0.01). These data emphasize the role of oxidative stress in the development of early neurovascular changes in experimental diabetes and show that naturally available scavengers have a neuroprotective action. PMID:8582537

  10. NMDA-induced rhythmical activity in XII nerve of isolated CNS from newborn rats.

    PubMed

    Katakura, N; Jia, L; Nakamura, Y

    1995-03-01

    We tried to induce rhythmical oro-facial motor activities in an isolated brain stem-spinal cord preparation from newborn rats. Neural activities were monitored from the hypoglossal nerve (XII N) and the ventral roots of the cervical cord. Bath application of N-methyl-D-aspartate (NMDA) as well as glutamate induced rhythmical burst activity in XII N distinct from and much faster than respiratory rhythm. This NMDA-induced rhythmical activity was blocked by simultaneous application of 2-amino-5-phosphonovalerate (AP5). The results demonstrate that NMDA receptor activation can induce rhythmical XII N activity different from respiration in an isolated mammalian CNS. This preparation will be useful for the investigation of neural mechanisms underlying the central generation of food ingestive movements. PMID:7605909

  11. Oxytocin nerve fibers innervate beta-endorphin neurons in the arcuate nucleus of the rat hypothalamus.

    PubMed

    Csiffáry, A; Ruttner, Z; Tóth, Z; Palkovits, M

    1992-09-01

    Fine, varicose oxytocin-containing nerve fibers have been demonstrated in the hypothalamic arcuate nucleus in rats. Using Phaseolus vulgaris leukoagglutinin as an anterograde tracer, fine neuronal fibers of paraventricular nucleus origin could be seen throughout the arcuate nucleus. Using double immunostaining, oxytocin-immunoreactive varicose fibers were observed around or in the close vicinity of beta-endorphin-immunoreactive neurons. Silver-gold-labeled oxytocin-immunoreactive presynaptic boutons were shown to make synaptic contacts with diaminobenzidine-labeled beta-endorphin-immunoreactive neurons by electron microscopy. These findings provide morphological evidence for a possible influence of oxytocin on the activity of the brain beta-endorphin system at the hypothalamic level. PMID:1279446

  12. Enriched Environment Protects the Optic Nerve from Early Diabetes-Induced Damage in Adult Rats

    PubMed Central

    Dorfman, Damián; Aranda, Marcos L.; Rosenstein, Ruth E.

    2015-01-01

    Diabetic retinopathy is a leading cause of reduced visual acuity and acquired blindness. Axoglial alterations of the distal (close to the chiasm) optic nerve (ON) could be the first structural change of the visual pathway in streptozotocin (STZ)-induced diabetes in rats. We analyzed the effect of environmental enrichment on axoglial alterations of the ON provoked by experimental diabetes. For this purpose, three days after vehicle or STZ injection, animals were housed in enriched environment (EE) or remained in a standard environment (SE) for 6 weeks. Anterograde transport, retinal morphology, optic nerve axons (toluidine blue staining and phosphorylated neurofilament heavy immunoreactivity), microglia/macrophages (ionized calcium binding adaptor molecule 1 (Iba-1) immunoreactivity), astrocyte reactivity (glial fibrillary acid protein-immunostaining), myelin (myelin basic protein immunoreactivity), ultrastructure, and brain derived neurotrophic factor (BDNF) levels were assessed in non-diabetic and diabetic animals housed in SE or EE. No differences in retinal morphology or retinal ganglion cell number were observed among groups. EE housing which did not affect the STZ-induced weight loss and hyperglycemia, prevented a decrease in the anterograde transport from the retina to the superior colliculus, ON axon number, and phosphorylated neurofilament heavy immunoreactivity. Moreover, EE housing prevented an increase in Iba-1 immunoreactivity, and astrocyte reactivity, as well as ultrastructural myelin alterations in the ON distal portion at early stages of diabetes. In addition, EE housing avoided a decrease in BDNF levels induced by experimental diabetes. These results suggest that EE induced neuroprotection in the diabetic visual pathway. PMID:26312758

  13. Transcutaneous Auricular Vagus Nerve Stimulation Protects Endotoxemic Rat from Lipopolysaccharide-Induced Inflammation

    PubMed Central

    Zhao, Yu Xue; He, Wei; Jing, Xiang Hong; Liu, Jun Ling; Rong, Pei Jing; Ben, Hui; Liu, Kun; Zhu, Bing

    2012-01-01

    Background. Transcutaneous auricular vagus nerve stimulation (ta-VNS) could evoke parasympathetic activities via activating the brainstem autonomic nuclei, similar to the effects that are produced after vagus nerve stimulation (VNS). VNS modulates immune function through activating the cholinergic anti-inflammatory pathway. Methods. VNS, ta-VNS, or transcutaneous electrical acupoint stimulation (TEAS) on ST36 was performed to modulate the inflammatory response. The concentration of serum proinflammatory cytokines and tissue NF-kappa B p65 (NF-κB p65) were detected in endotoxaemia affected anesthetized rats. Results. Similar to the effect of VNS, ta-VNS suppressed the serum proinflammatory cytokines levels, such as tumour necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β), and interleukin-6 (IL-6) as well as NF-kappa B p65 expressions of lung tissues. ST36 stimulation also decreases LPS-induced high TNF-α level and NF-κB signal, but it did not restrain proinflammatory cytokine IL-1β and IL-6. Neither ta-VNS nor ST36 stimulation could suppress LPS-induced TNF-α and NF-κB after vagotomy or with α7nAChR antagonist injection. Conclusions. The present paper demonstrated that ta-VNS could be utilized to suppress LPS-induced inflammatory responses via α7nAChR-mediated cholinergic anti-inflammatory pathway. PMID:23346208

  14. Nerve-pathways of acupoint Fengch’ih in rat by anterograde transport of HRP

    PubMed Central

    Xi, Gang-Ming; Wang, Hua-Qiao; He, Guo-Hou; Huang, Chao-Feng; Yuan, Qun-Fang; Wei, Guo-Yao; Li, Hua; Liu, Wen-Wen; Fan, Hua-Yan

    2005-01-01

    AIM: To study the nervous-pathways of Fengch’ih acupuncture by means of anterograde transport of aqueous solution of horseradish peroxidase (HRP). METHODS: Fifty Wistar rats were randomly divided into 1, 2, 3, 4, and 5 d groups, and every group had 10 animals. HRP (30% aqueous solution) was injected into a Fengch’ih. Serial, transverse or capital, 40 μm sections of the cervical spinal ganglia, cervical and thoracic spinal cord segment and brain were cut on a cryotome. Sections were incubated for HRP histochemistry according to the tetramethylbenzidine (TMB). Part of the sections were counterstained with neutral red. RESULTS: After 1 d of survival times, many labeled cell bodies were found in 1-4 cervical spinal ganglia, anterior horn of 1-4 cervical spinal cord, ventromedial division of facial nucleus, accessory facial nucleus ipsilaterally. With increasing survival times, the intensity of labeled cells were slightly decreased. CONCLUSION: Fengch’ih may bring into full play its effect by correlation of posterior ear branch of facial nerve and anterior branch of 2-3 cervical nerve with 1-4 cervical the anterior horn of the spinal cord, ventromedial division of facial nucleus, accessory facial nucleus. PMID:15918204

  15. Enriched Environment Protects the Optic Nerve from Early Diabetes-Induced Damage in Adult Rats.

    PubMed

    Dorfman, Damián; Aranda, Marcos L; Rosenstein, Ruth E

    2015-01-01

    Diabetic retinopathy is a leading cause of reduced visual acuity and acquired blindness. Axoglial alterations of the distal (close to the chiasm) optic nerve (ON) could be the first structural change of the visual pathway in streptozotocin (STZ)-induced diabetes in rats. We analyzed the effect of environmental enrichment on axoglial alterations of the ON provoked by experimental diabetes. For this purpose, three days after vehicle or STZ injection, animals were housed in enriched environment (EE) or remained in a standard environment (SE) for 6 weeks. Anterograde transport, retinal morphology, optic nerve axons (toluidine blue staining and phosphorylated neurofilament heavy immunoreactivity), microglia/macrophages (ionized calcium binding adaptor molecule 1 (Iba-1) immunoreactivity), astrocyte reactivity (glial fibrillary acid protein-immunostaining), myelin (myelin basic protein immunoreactivity), ultrastructure, and brain derived neurotrophic factor (BDNF) levels were assessed in non-diabetic and diabetic animals housed in SE or EE. No differences in retinal morphology or retinal ganglion cell number were observed among groups. EE housing which did not affect the STZ-induced weight loss and hyperglycemia, prevented a decrease in the anterograde transport from the retina to the superior colliculus, ON axon number, and phosphorylated neurofilament heavy immunoreactivity. Moreover, EE housing prevented an increase in Iba-1 immunoreactivity, and astrocyte reactivity, as well as ultrastructural myelin alterations in the ON distal portion at early stages of diabetes. In addition, EE housing avoided a decrease in BDNF levels induced by experimental diabetes. These results suggest that EE induced neuroprotection in the diabetic visual pathway. PMID:26312758

  16. Vanilloid receptors mediate adrenergic nerve- and CGRP-containing nerve-dependent vasodilation induced by nicotine in rat mesenteric resistance arteries

    PubMed Central

    Eguchi, Shinji; Tezuka, Satoko; Hobara, Narumi; Akiyama, Shinji; Kurosaki, Yuji; Kawasaki, Hiromu

    2004-01-01

    Previous studies showed that nicotine induces adrenergic nerve-dependent vasodilation that is mediated by endogenous calcitonin gene-related peptide (CGRP) released from CGRP-containing (CGRPergic) nerves. The mechanisms underlying the nicotine-induced vasodilation were further studied. Rat mesenteric vascular beds without endothelium were contracted by perfusion with Krebs solution containing methoxamine, and the perfusion pressure was measured with a pressure transducer. Perfusion of nicotine (1–100 μM) for 1 min caused concentration-dependent vasodilation. Capsazepine (vanilloid receptor-1 antagonist; 1–10 μM) and ruthenium red (inhibitor of vanilloid response; 1–30 μM) concentration-dependently inhibited the nicotine-induced vasodilation without affecting the vasodilator response to exogenous CGRP. Nicotine-induced vasodilation was not inhibited by treatment with 3,4-dihydroxyphenylalanine (DOPA) receptor antagonist (L-DOPA cyclohexyl ester; 0.001–10 μM), dopamine D1 receptor-selective antagonist (SCH23390; 1–10 μM), dopamine D2 receptor antagonist (haloperidol; 0.1–0.5 μM), ATP P2x receptor-desensitizing agonist (α,β-methylene ATP; 1–10 μM), adenosine A2 receptor antagonist (8(p-sulfophenyl)theophylline; 10–50 μM) or neuropeptide Y (NPY)-Y1 receptor antagonist (BIBP3226; 0.1–0.5 μM). Immunohistochemical staining of the mesenteric artery showed dense innervation of CGRP- and vanilloid receptor-1-positive nerves, with both immunostainings appearing in the same neuron. The mesenteric artery was also densely innervated by NPY-positive nerves. Double immunostainings showed that both NPY and CGRP immunoreactivities appeared in the same neuron of the artery. These results suggest that nicotine acts on presynaptic nicotinic receptors to release adrenergic neurotransmitter(s) or related substance(s), which then stimulate vanilloid receptor-1 on CGRPergic nerves, resulting in CGRP release and vasodilation. PMID:15249421

  17. Sodium currents and sodium-current fluctuations in rat myelinated nerve fibres

    PubMed Central

    Neumcke, B.; Stämpfli, R.

    1982-01-01

    1. Sodium currents and fluctuations of sodium currents were measured in myelinated fibres of rat sciatic nerve under voltage clamp at 20 °C. 2. Relaxations of sodium currents during various test potentials were recorded in the presence of 6 nM-TTX in the extracellular solution. The activation of sodium currents at low depolarizations could be described with the m2 formulation. At increasing potentials higher powers of m up to 4 were required. The mid-point of the PNa (E) curve was located near E = -32 mV. Sodium inactivation during various depolarizations developed in two phases. 3. The resistance in series with the nodal membrane was calculated from peak sodium currents without and with 6 nM-TTX in the extracellular solution. The resistance varied between different fibres and ranged between 190 and 620 kΩ. 4. From peak sodium currents at the same mambrane potential without and in the presence of TTX an apparent equilibrium dissociation constant of 1·6 nM was calculated for TTX binding to sodium channels. 5. The conductance γ and the number N0 (corrected for series-resistance effects) of sodium channels were evaluated from ensemble average values of the mean sodium current and the variance of sodium-current fluctuations at the beginning of a test pulse. The mean values were γ = 14·5 pS, N0 = 21,000 per node. 6. The spectral density of stationary sodium-current fluctuations exhibited two relaxation components whose time constants were comparable to those of sodium activation and inactivation. At low depolarizations the variance produced by inactivation fluctuations was larger than predicted by the m3. h formulation. 7. It is concluded that individual sodium channels of rat and frog nerve have similar gating properties. In mammalian nodes the number of sodium channels is lower and the single-channel conductance higher than in amphibian nodes. PMID:6292404

  18. Neuroprotection and reduction of glial reaction by cannabidiol treatment after sciatic nerve transection in neonatal rats.

    PubMed

    Perez, Matheus; Benitez, Suzana U; Cartarozzi, Luciana P; Del Bel, Elaine; Guimarães, Francisco S; Oliveira, Alexandre L R

    2013-11-01

    In neonatal rats, the transection of a peripheral nerve leads to an intense retrograde degeneration of both motor and sensory neurons. Most of the axotomy-induced neuronal loss is a result of apoptotic processes. The clinical use of neurotrophic factors is difficult due to side effects and elevated costs, but other molecules might be effective and more easily obtained. Among them, some are derived from Cannabis sativa. Cannabidiol (CBD) is the major non-psychotropic component found on the surface of such plant leaves. The present study aimed to investigate the neuroprotective potential of CBD. Thus, 2-day-old Wistar rats were divided into the following experimental groups: sciatic nerve axotomy + CBD treatment (CBD group), axotomy + vehicle treatment (phosphate buffer group) and a control group (no-treatment group). The results were analysed by Nissl staining, immunohistochemistry and terminal deoxynucleotidyl transferase dUTP nick end labeling at 5 days post-lesion. Neuronal counting revealed both motor and sensory neuron rescue following treatment with CBD (15 and 30 mg/kg). Immunohistochemical analysis (obtained by synaptophysin staining) revealed 30% greater synaptic preservation within the spinal cord in the CBD-treated group. CBD administration decreased the astroglial and microglial reaction by 30 and 27%, respectively, as seen by glial fibrillary acidic protein and ionised calcium binding adaptor molecule 1 immunolabeling quantification. In line with such results, the terminal deoxynucleotidyl transferase dUTP nick end labeling reaction revealed a reduction of apoptotic cells, mostly located in the spinal cord intermediate zone, where interneurons promote sensory-motor integration. The present results show that CBD possesses neuroprotective characteristics that may, in turn, be promising for future clinical use. PMID:23981015

  19. Nociceptive and Neuronal Evaluation of the Sciatic Nerve of Wistar Rats Subjected to Compression Injury and Treated with Resistive Exercise.

    PubMed

    Antunes, Juliana Sobral; Lovison, Keli; Karvat, Jhenifer; Peretti, Ana Luiza; Vieira, Lizyana; Higuchi, Guilherme Hideaki; Brancalhão, Rose Meire Costa; Ribeiro, Lucinéia de Fátima Chasko; Bertolini, Gladson Ricardo Flor

    2016-01-01

    Background. To investigate the climb stairs resistance exercise on nociception and axonal regeneration in the sciatic nerve of rats. Methods. 24 Wistar rats were divided: control group (CG-no injury), exercise group (EG-no injury with physical exercise), lesion group (LG-injury, but without exercise), and treated group (LEG-injury and physical exercise). LG and LEG were subjected to sciatic nerve compression with hemostat. From the 3rd day after injury began treatment with exercise, and after 22 days occurs the removal of a nerve fragment for morphological analysis. Results. Regarding allodynia, CG obtained values less than EG (p = 0.012) and larger than LG and LEG (p < 0.001). Histological results showed that CG and EG had normal appearance, as LG and LEG showed up with large amounts of inflammatory infiltration, degeneration and disruption of nerve fibers, and reduction of the myelin sheath; however LEG presented some regenerated fibers. From the morphometric data there were significant differences, for nerve fiber diameter, comparing CG with LG and LEG and comparing axon diameter and the thickness of the myelin of the CG to others. Conclusion. Climb stairs resistance exercise was not effective to speed up the regenerative process of axons. PMID:27594795

  20. Nociceptive and Neuronal Evaluation of the Sciatic Nerve of Wistar Rats Subjected to Compression Injury and Treated with Resistive Exercise

    PubMed Central

    Antunes, Juliana Sobral; Lovison, Keli; Karvat, Jhenifer; Peretti, Ana Luiza; Vieira, Lizyana; Higuchi, Guilherme Hideaki; Ribeiro, Lucinéia de Fátima Chasko

    2016-01-01

    Background. To investigate the climb stairs resistance exercise on nociception and axonal regeneration in the sciatic nerve of rats. Methods. 24 Wistar rats were divided: control group (CG—no injury), exercise group (EG—no injury with physical exercise), lesion group (LG—injury, but without exercise), and treated group (LEG—injury and physical exercise). LG and LEG were subjected to sciatic nerve compression with hemostat. From the 3rd day after injury began treatment with exercise, and after 22 days occurs the removal of a nerve fragment for morphological analysis. Results. Regarding allodynia, CG obtained values less than EG (p = 0.012) and larger than LG and LEG (p < 0.001). Histological results showed that CG and EG had normal appearance, as LG and LEG showed up with large amounts of inflammatory infiltration, degeneration and disruption of nerve fibers, and reduction of the myelin sheath; however LEG presented some regenerated fibers. From the morphometric data there were significant differences, for nerve fiber diameter, comparing CG with LG and LEG and comparing axon diameter and the thickness of the myelin of the CG to others. Conclusion. Climb stairs resistance exercise was not effective to speed up the regenerative process of axons. PMID:27594795

  1. Effects of interleukin-1 beta injections into the subfornical organ and median preoptic nucleus on sodium appetite, blood pressure and body temperature of sodium-depleted rats.

    PubMed

    Cerqueira, Diana R; Ferreira, Hilda S; Moiteiro, Andrei L B B; Fregoneze, Josmara B

    2016-09-01

    Interleukin-1β (IL-1β) appears to be the mediator of the reciprocal communication between the brain and the immune system. IL-1β has been shown to modulate homeostatic functions including fever, feeding, drinking and cardiovascular control. The aim of the present study was to investigate the effects of IL-1β injections directly into the subfornical organ (SFO) and the median preoptic nucleus (MnPO) on salt appetite, hedonic response, locomotion, body temperature and blood pressure in sodium-depleted rats. IL-1β injections into the SFO and MnPO at the doses of 0.2, 0.4, 0.8 and 1.6ng/0.2μl promoted a dose-dependent inhibition of salt intake in sodium-depleted rats. Results of the "dessert" test and the "open field" test suggested that the inhibition of salt appetite is not due to any changes in the hedonic aspect of ingestive behavior or to changes in locomotor activity. As expected, IL-1β injections into the SFO and MnPO promoted an increase in body temperature. However, the fever induced by IL-1β injected into the SFO was slower than the increase in body temperature obtained following IL-1β injection into the MnPO. Furthermore, IL-1β at a dose of 1.6ng/0.2μl directly injected into the MnPO led to a significant increase in blood pressure, while injection of the same concentration of IL-1β into the SFO caused no significant change in blood pressure or heart rate. The action of pro-inflammatory cytokines may interfere with the normal control of body temperature, blood pressure and fluid homeostasis, producing the adjustment required to cope with infection and inflammation. Further studies are required to clarify the mechanisms involved in fever, blood pressure increase and inhibition of sodium appetite induced by injections of IL-1β into the SFO and MnPO in sodium-depleted rats. PMID:27163523

  2. An analysis of the anatomical basis for the mechanical response to motor nerve stimulation of the rat vas deferens

    PubMed Central

    Anton, Patricia G.; Duncan, Morag E.; McGrath, J. C.

    1977-01-01

    1. An anatomical basis was sought for the biphasic motor nerve response of the rat vas deferens. The motor nerve pathway to the tissue was stimulated at different points between the vertebral outflow and the intramural fibres, in the pithed rat and in isolated tissues, to examine the possibility of two anatomically separate groups of neurones. Different preparations of the isolated tissue were devised to detect whether different groups of smooth muscle fibres contributed to the two phases. 2. The fibres mediating both phases of the response arose from the upper lumbar vertebral outflows. Both phases were elicited by pre- or post-ganglionic stimulation and could be depressed by hexamethonium. In the pithed rat or with hypogastric nerve stimulation in the isolated tissue, however, the initial `twitch' phase was relatively resistant to such blockade. 3. When the rat vas deferens was perfused through the lumen in situ or in vitro, the perfusion pressure response to motor nerve stimulation exhibited two phases similar to those of the longitudinal contractile response. 4. Isolated rat vasa were bisected into portions, each of which was stimulated and longitudinal tension was recorded. The proportions of the two phases of the response varied along the length of the tissue. At the prostatic end the total response was relatively weak with a dominant `twitch' and at the epididymal end the two phases were comparable in magnitude. The distribution of adrenergic nerve terminals within the muscle layers also varied along the length of the rat vas deferens. 5. The effects of drugs were investigated on the motor responses of the above preparations. The `twitch' phase was relatively susceptible to blockade by reserpine and lysergic acid diethylamide and the `secondary' phase to phentolamine with both equally sensitive to guanethidine. Each phase had similar susceptibilities to blockade irrespective of which part of the tissue was involved. 6. It was concluded that two types of

  3. A System for Studying Facial Nerve Function in Rats through Simultaneous Bilateral Monitoring of Eyelid and Whisker Movements

    PubMed Central

    Heaton, James T.; Kowaleski, Jeffrey M.; Bermejo, Roberto; Zeigler, H. Philip; Ahlgren, David J.; Hadlock, Tessa A.

    2008-01-01

    The occurrence of inappropriate co-contraction of facially innervated muscles in humans (synkinesis) is a common sequela of facial nerve injury and recovery. We have developed a system for studying facial nerve function and synkinesis in restrained rats using non-contact opto-electronic techniques that enable simultaneous bilateral monitoring of eyelid and whisker movements. Whisking is monitored in high spatio-temporal resolution using laser micrometers, and eyelid movements are detected using infrared diode and phototransistor pairs that respond to the increased reflection when the eyelids cover the cornea. To validate the system, eight rats were tested with multiple five-minute sessions that included corneal air puffs to elicit blink and scented air flows to elicit robust whisking. Four rats then received unilateral facial nerve section and were tested at weeks 3–6. Whisking and eye blink behavior occurred both spontaneously and under stimulus control, with no detectable difference from published whisking data. Proximal facial nerve section caused an immediate ipsilateral loss of whisking and eye blink response, but some ocular closures emerged due to retractor bulbi muscle function. The independence observed between whisker and eyelid control indicates that this system may provide a powerful tool for identifying abnormal co-activation of facial zones resulting from aberrant axonal regeneration. PMID:18442856

  4. Hydrogen-Rich Saline Promotes Survival of Retinal Ganglion Cells in a Rat Model of Optic Nerve Crush

    PubMed Central

    Zuo, Qiao; Wang, Ruo-bing; Qi, Ai-qing; Cao, Wen-luo; Sun, Ai-jun; Sun, Xue-jun; Xu, Jiajun

    2014-01-01

    Objective To investigate the effect of molecular hydrogen (H2) in a rat model subjected to optic nerve crush (ONC). Methods We tested the hypothesis that after optic nerve crush (ONC), retinal ganglion cell (RGC) could be protected by H2. Rats in different groups received saline or hydrogen-rich saline every day for 14 days after ONC. Retinas from animals in each group underwent measurements of hematoxylin and eosin (H&E) staining, cholera toxin beta (CTB) tracing, gamma synuclein staining, and terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling (TUNEL) staining 2 weeks post operation. Flash visual evoked potentials (FVEP) and pupillary light reflex (PLR) were then tested to evaluate the function of optic nerve. The malondialdehyde (MDA) level in retina was evaluated. Results H&E, gamma synuclein staining and CTB tracing showed that the survival rate of RGCs in hydrogen saline-treated group was significantly higher than that in saline-treated group. Apoptosis of RGCs assessed by TUNEL staining were less observed in hydrogen saline-treated group. The MDA level in retina of H2 group was much lower than that in placebo group. Furthermore, animals treated with hydrogen saline showed better function of optic nerve in assessments of FVEP and PLR. Conclusion These results demonstrated that H2 protects RGCs and helps preserve the visual function after ONC and had a neuroprotective effect in a rat model subjected to ONC. PMID:24915536

  5. In vivo fibre optic confocal imaging of microvasculature and nerves in the rat vas deferens and colon

    PubMed Central

    PAPWORTH, G. D.; DELANEY, P. M.; BUSSAU, L. J.; VO, L. T.; KING, R. G.

    1998-01-01

    A fluorescence confocal microscopy technique was employed to obtain subsurface images of nerve and microvascular structure in the vas deferens and colon of the living rat. The use of dual labelling with vital dyes and 2-channel confocal acquisition allowed differentiation of microscopic structure at both low and higher magnification. Characteristic staining patterns of nerves and blood vessels were repeatedly obtained in each tissue, suggesting the potential of this technique for studying morphological changes associated with surgical procedures and/or models of neuronal or vascular pathology. PMID:9723976

  6. Inhibition of the NMDA receptor protects the rat sciatic nerve against ischemia/reperfusion injury

    PubMed Central

    KE, TIE; LI, RENBIN; CHEN, WENCHANG

    2016-01-01

    Inhibition of the N-methyl-D-aspartate (NMDA) receptor by MK-801 reduces ischemia/reperfusion (I/R) injury in the central nervous system. However, few previous studies have evaluated the neuroprotective effects of MK-801 against peripheral I/R injury. The present study aimed to investigate the protective effects of MK-801 pretreatment against I/R injury in the rat sciatic nerve (SN). Sprague-Dawley rats were subjected to a sham surgery (n=8) or to a 5-h ischemic insult by femoral artery clamping (I/R and I/R+MK-801 groups; n=48 per group). I/R+MK-801 rats were intraperitoneally injected with MK-801 (0.5 ml or 1 mg/kg) at 15 min prior to reperfusion. The rats were sacrificed at 0, 6, 12, 24, 72 h, or 7 days following reperfusion. Plasma malondialdehyde (MDA) and nitric oxide (NO) concentrations, and SN inducible NO synthase (iNOS) protein expression levels, were measured using colorimetry. In addition, the protein expression levels of tumor necrosis factor-α (TNF-α) were measured using immunohistochemistry, and histological analyses of the rat SN were conducted using light and electron microscopy. Alterations in the mRNA expression levels of TNF-α and TNF-α converting enzyme (TACE) in the rat SN were detected using reverse transcription-quantitative polymerase chain reaction. In the I/R group, plasma concentrations of NO (175.3±4.2 µmol/l) and MDA (16.2±1.9 mmol/l), and the levels of iNOS (2.5±0.3) in the SN, peaked at 24 h post-reperfusion. At 24 h, pretreatment with MK-801 significantly reduced plasma NO (107.3±3.6 µmol/l) and MDA (11.8±1.6 mmol/l), and SN iNOS (1.65±0.2) levels (all P<0.01). The mRNA expression levels of TNF-α and TACE in the SN were significantly reduced in the I/R+MK-801 group, as compared with the I/R group (P<0.05). Furthermore, MK-801 pretreatment was shown to have alleviated histological signs of I/R injury, including immune cell infiltration and axon demyelination. The results of the present study suggested that pretreatment

  7. Effect of Hyaluronic Acid-Carboxymethylcellulose Solution on Perineural Scar Formation after Sciatic Nerve Repair in Rats

    PubMed Central

    Park, Jin Sung; Han, Chung Soo; Chung, Duke Whan; Kim, Gou Young

    2011-01-01

    Background Scar tissue formation is the major cause of failure in peripheral nerve surgery. Use of a hyaluronic acid-carboxymethylcellulose (HA-CMC) membrane (Seprafilm) as a solid anti-adhesion barrier agent is one of the therapeutic approaches to reduce postoperative scar tissue formation. However, a solid membrane may not be suitable for repair of a weak peripheral nerve site. This study examined the effect of HA-CMC solution on perineural scar formation after peripheral nerve repair in rats. Methods The sciatic nerves of 40 rats were transected and then immediately repaired using 10-0 nylon. The nerves were divided randomly into two groups. Saline and HA-CMC solution were applied topically to the nerve repair sites in the control and experimental groups, respectively. Reoperation was performed at 3, 6, 9, and 12 weeks to assess scar tissue formation. The assessment included the quality of wound healing, presence of perinueral adhesion, cellular components of the scar tissue, thickness of the scar tissue and histomorphological organization of the repair site. Results Topical application of the HA-CMC solution significantly decreased the macroscopic nerve adherence score and the numbers of the cellular components such as fibroblasts and inflammatory cells (p < 0.05, Mann-Whitney U-test). The scar tissue formation index was significantly lower in the experimental group at 12 weeks than that in the control group (p < 0.05, Mann-Whitney U-test). The grading scores of the histomorphological axonal organization at the repair site were significantly higher in the experimental group than those in the control group at 12 weeks (p < 0.05, Mann-Whitney U-test). No evidence of wound dehiscence or inflammatory reactions against the HA-CMC solution was noted. Conclusions Topical application of a HA-CMC solution is effective in reducing the perineural scar formation and adhesion after sciatic nerve repair in rats, and is effective in promoting peripheral nerve regeneration at

  8. Electrical stimulation vs. pulsed and continuous-wave optical stimulation of the rat prostate cavernous nerves, in vivo

    NASA Astrophysics Data System (ADS)

    Perkins, William C.; Lagoda, Gwen A.; Burnett, Arthur; Fried, Nathaniel M.

    2015-07-01

    Identification and preservation of the cavernous nerves (CNs) during prostate cancer surgery is critical for post-operative sexual function. Electrical nerve stimulation (ENS) mapping has previously been tested as an intraoperative tool for CN identification, but was found to be unreliable. ENS is limited by the need for electrode-tissue contact, poor spatial precision from electrical current spreading, and stimulation artifacts interfering with detection. Alternatively, optical nerve stimulation (ONS) provides noncontact stimulation, improved spatial selectivity, and elimination of stimulation artifacts. This study compares ENS to pulsed/CW ONS to explore the ONS mechanism. A total of eighty stimulations were performed in 5 rats, in vivo. ENS (4 V, 5 ms, 10 Hz) was compared to ONS using a pulsed diode laser nerve stimulator (1873 nm, 5 ms, 10 Hz) or CW diode laser nerve stimulator (1455 nm). Intracavernous pressure (ICP) response and nerve compound action potentials (nCAPs) were measured. All three stimulation modes (ENS, ONS-CW, ONS-P) produced comparable ICP magnitudes. However, ENS demonstrated more rapid ICP response times and well defined nCAPs compared to unmeasurable nCAPs for ONS. Further experiments measuring single action potentials during ENS and ONS are warranted to further understand differences in the ENS and ONS mechanisms.

  9. An attempt to assess functionally minimal acetylcholinesterase activity necessary for survival of rats intoxicated with nerve agents.

    PubMed

    Bajgar, Jiri; Fusek, Josef; Kassa, Jiri; Jun, Daniel; Kuca, Kamil; Hajek, Petr

    2008-09-25

    Acetylcholinesterase (AChE, EC 3.1.1.7) is an important enzyme for cholinergic nerve transmission. The action of toxic organophosphates such as nerve agents is based on AChE inhibition. The death following acute nerve agent poisoning is due to central or peripheral respiratory/cardiac failure. Therefore, the changes in AChE activity following nerve agents acting predominantly on the central (sarin, soman) or peripheral (VX) level were studied. It is known that AChE activity in different structures exists in relative excess. Female Wistar rats intoxicated with sarin, soman, and VX in different doses (0.5-2.0 x LD(50)) were divided into groups of survived and died animals. AChE activities in diaphragm, brain parts (pontomedullar area, frontal cortex, basal ganglia, in some cases other parts of the brain) were determined and the rest of activity (in %) was correlated with survival/death of animals. More precise elucidation of action of nerve agents and the assessment of minimal AChE activity in different organs compatible with the survival of organism poisoned with nerve agents were the aims of this study. PMID:18579126

  10. Migration and Differentiation of Neural Progenitor Cells after Recurrent Laryngeal Nerve Avulsion in Rats

    PubMed Central

    Zhao, Wan; Xu, Wen

    2014-01-01

    To investigate migration and differentiation of neural progenitor cells (NPCs) from the ependymal layer to the nucleus ambiguus (NA) after recurrent laryngeal nerve (RLN) avulsion. All of the animals received a CM-DiI injection in the left lateral ventricle. Forty-five adult rats were subjected to a left RLN avulsion injury, and nine rats were used as controls. 5-Bromo-2-deoxyuridine (BrdU) was injected intraperitoneally. Immunohistochemical analyses were performed in the brain stems at different time points after RLN injury. After RLN avulsion, the CM-DiI+ NPCs from the ependymal layer migrated to the lesioned NA. CM-DiI+/GFAP+ astrocytes, CM-DiI+/DCX+ neuroblasts and CM-DiI+/NeuN+ neurons were observed in the migratory stream. However, the ipsilateral NA included only CM-DiI+ astrocytes, not newborn neurons. After RLN avulsion, the NPCs in the ependymal layer of the 4th ventricle or central canal attempt to restore the damaged NA. We first confirm that the migratory stream includes both neurons and glia differentiated from the NPCs. However, only differentiated astrocytes are successfully incorporated into the NA. The presence of both cell types in the migratory process may play a role in repairing RLN injuries. PMID:25202908

  11. Reflex control of rat tail sympathetic nerve activity by abdominal temperature

    PubMed Central

    Shafton, Anthony D; Kitchener, Peter; McKinley, Michael J; McAllen, Robin M

    2014-01-01

    The thermoregulatory reflex effects of warming and cooling in the abdomen were investigated in 4 urethane-anesthetized Sprague-Dawley rats. Animals were shaved and surrounded by a water-perfused silastic jacket. Skin temperature under the jacket was recorded by thermocouples at 3 sites and brain temperature was monitored by a thermocouple inserted lateral to the hypothalamus. A heat exchanger made from an array of silicon tubes in parallel loops was placed through a ventral incision into the abdomen; it rested against the intestinal serosa and the temperature of this interface was monitored by a thermocouple. Few- or multi-unit postganglionic activity was recorded from sympathetic nerves supplying tail vessels (tail SNA). Intra-abdominal temperature was briefly lowered or raised between 35–41 °C by perfusing the heat exchanger with cold or warm water. Warming the abdomen inhibited tail SNA while cooling it excited tail SNA in all 4 animals. We also confirmed that cooling the trunk skin activated tail SNA. Multivariate analysis of tail SNA with respect to abdominal, brain and trunk skin temperatures revealed that all had highly significant independent inhibitory actions on tail SNA, but in these experiments abdominal temperature had the weakest and brain temperature the strongest effect. We conclude that abdominal temperature has a significant thermoregulatory action in the rat, but its influence on cutaneous vasomotor control appears to be weaker than that of skin or brain temperatures.

  12. The Role of Lumbar Sympathetic Nerves in Regulation of Blood Flow to Skeletal Muscle during Anaphylactic Hypotension in Anesthetized Rats.

    PubMed

    Song, Jie; Tanida, Mamoru; Shibamoto, Toshishige; Zhang, Tao; Wang, Mofei; Kuda, Yuhichi; Kurata, Yasutaka

    2016-01-01

    During hypovolemic shock, skeletal muscle blood flow could be redistributed to vital organs via vasoconstriction in part evoked by activation of the innervating sympathetic nerve activity. However, it is not well known whether this mechanism operates during anaphylactic shock. We determined the femoral artery blood flow (FBF) and lumbar sympathetic nerve activity (LSNA) mainly regulating the hindquater muscle blood flow during anaphylactic hypotension in anesthetized rats. Anesthetized Sprague-Dawley rats were randomly allocated to the following groups (n = 7/group): (1) non-sensitized, (2) anaphylaxis, (3) anaphylaxis-lumbar sympathectomy (LS) and (4) anaphylaxis-sinoaortic denervation (SAD) groups. Anaphylaxis was induced by an intravenous injection of the ovalbumin antigen to the sensitized rats. The systemic arterial pressure (SAP), heart rate (HR), central venous pressure (CVP), FBF and LSNA were continuously measured. In the anaphylaxis group, LSNA and HR increased, while SAP and FBF decreased after antigen injection. In the anaphylaxis-SAD group, LSNA did not significantly change during the early phase, but the responses of SAP and FBF were similar to those in the anaphylaxis group. In the anaphylaxis-LS group, both FBF and SAP decreased similarly to the anaphylaxis group during anaphylactic hypotension. These results indicated that LSNA increased via baroreceptor reflex, but this sympathoexcitation or LS did not affect antigen-induced decreases in FBF or SAP. Lumbar sympathetic nerves are not involved in regulation of the blood flow to the hindlimb or systemic blood pressure during anaphylactic hypotension in anesthetized rats. PMID:26998924

  13. Greater Superficial Petrosal Nerve Transection in Rats does not Change Unconditioned Licking Responses to Putatively Sweet Taste Stimuli

    PubMed Central

    Jiang, Enshe; Blonde, Ginger; Garcea, Mircea

    2008-01-01

    The greater superficial petrosal nerve (GSP), innervating taste buds in the palate, is known to be exceptionally responsive to sucrose, especially compared with the responsiveness of the chorda tympani nerve (CT). However, whereas transection of the CT (CTX) alone has little or no effect on unconditioned licking responses to many “sweet” stimuli, the impact of GSP transection (GSPX) alone is equivocal. To further examine the role of the GSP on licking responses to putatively sweet-tasting substances, brief-access taste tests were conducted in nondeprived rats before and after sham surgery (SHAM) or CTX or GSPX. A range of concentrations of sucrose, L-alanine, glycine, and L-serine, with and without 1.0 mM inosine monophosphate (IMP) added, were used. All groups showed significant concentration-dependent increases in licking to all stimuli presurgically and postsurgically. CTX decreased licking responses relative to SHAM rats in the first sucrose test. There was also a group × concentration interaction for L-alanine, but post hoc tests did not reveal its basis. Other than this, there were no significant differences among the surgical groups. Interestingly, rats with GSPX tended to initiate fewer trials than SHAM rats. Overall, after GSPX, the remaining gustatory nerves are apparently sufficient to maintain concentration-dependent licking responses to all stimuli tested here. The disparity between our results and others in the literature where GSPX reduced licking responses to sucrose is possibly related to differences in surgical technique or test trial duration. PMID:18635557

  14. The Role of Lumbar Sympathetic Nerves in Regulation of Blood Flow to Skeletal Muscle during Anaphylactic Hypotension in Anesthetized Rats

    PubMed Central

    Shibamoto, Toshishige; Zhang, Tao; Wang, Mofei; Kuda, Yuhichi; Kurata, Yasutaka

    2016-01-01

    During hypovolemic shock, skeletal muscle blood flow could be redistributed to vital organs via vasoconstriction in part evoked by activation of the innervating sympathetic nerve activity. However, it is not well known whether this mechanism operates during anaphylactic shock. We determined the femoral artery blood flow (FBF) and lumbar sympathetic nerve activity (LSNA) mainly regulating the hindquater muscle blood flow during anaphylactic hypotension in anesthetized rats. Anesthetized Sprague-Dawley rats were randomly allocated to the following groups (n = 7/group): (1) non-sensitized, (2) anaphylaxis, (3) anaphylaxis-lumbar sympathectomy (LS) and (4) anaphylaxis-sinoaortic denervation (SAD) groups. Anaphylaxis was induced by an intravenous injection of the ovalbumin antigen to the sensitized rats. The systemic arterial pressure (SAP), heart rate (HR), central venous pressure (CVP), FBF and LSNA were continuously measured. In the anaphylaxis group, LSNA and HR increased, while SAP and FBF decreased after antigen injection. In the anaphylaxis-SAD group, LSNA did not significantly change during the early phase, but the responses of SAP and FBF were similar to those in the anaphylaxis group. In the anaphylaxis-LS group, both FBF and SAP decreased similarly to the anaphylaxis group during anaphylactic hypotension. These results indicated that LSNA increased via baroreceptor reflex, but this sympathoexcitation or LS did not affect antigen-induced decreases in FBF or SAP. Lumbar sympathetic nerves are not involved in regulation of the blood flow to the hindlimb or systemic blood pressure during anaphylactic hypotension in anesthetized rats. PMID:26998924

  15. Effect of an Adipose-Derived Stem Cell and Nerve Growth Factor-Incorporated Hydrogel on Recovery of Erectile Function in a Rat Model of Cavernous Nerve Injury

    PubMed Central

    Kim, In Gul; Piao, Shuyu; Lee, Ji Young; Hong, Sung Hoo; Hwang, Tae-Kon; Kim, Sae Woong; Kim, Choung Soo; Ra, Jeong Chan; Noh, Insup

    2013-01-01

    Postprostatectomy erectile dysfunction (ED) is the major problem for patients with clinically localized prostate cancer. Recently, gene and stem cell-based therapy of the corpus cavernosum has been attempted for postprostatectomy ED, but those therapies are limited by rapid blood flow and disruption of the normal architecture of the corpus cavernosum. In this study, we attempted to regenerate the damaged cavernous nerve (CN), which is the main cause of ED. We investigated the effectiveness of human adipose-derived stem cell (hADSC) and nerve growth factor-incorporated hyaluronic acid-based hydrogel (NGF-hydrogel) application on the CN in a rat model of bilateral cavernous nerve crush injury. Four weeks after the operation, erectile function was assessed by detecting the intracavernous pressure (ICP)/arterial pressure level by CN electrostimulation. The ICP was significantly increased by application of hADSC with NGF-hydrogel compared to the other experimental groups. CN and penile tissue were collected for histological examination. PKH-26 labeled hADSC colocalized with beta III tubulin were shown in CN tissue sections. hADSC/NGF-hydrogel treatment prevented smooth muscle atrophy in the corpus cavernosum. In addition, the hADSC/NGF-hydrogel group showed increased endothelial nitric oxide synthase protein expression. This study suggests that application of hADSCs with NGF-hydrogel on the CN might be a promising treatment for postprostatectomy ED. PMID:22834730

  16. Netrin-1 overexpression in bone marrow mesenchymal stem cells promotes functional recovery in a rat model of peripheral nerve injury

    PubMed Central

    Ke, Xianjin; Li, Qian; Xu, Li; Zhang, Ying; Li, Dongmei; Ma, Jianhua; Mao, Xiaoming

    2015-01-01

    Abstract Transplantation of bone marrow mesenchymal stem cells (BMSCs) has been developed as a new method of treating diseases of the peripheral nervous system. While netrin-1 is a critical molecule for axonal path finding and nerve growth, it may also affect vascular network formation. Here, we investigated the effect of transplanting BMSCs that produce netrin-1 in a rat model of sciatic nerve crush injury. We introduced a sciatic nerve crush injury, and then injected 1×106 BMSCs infected by a recombinant adenovirus expressing netrin-1 Ad5-Netrin-1-EGFP or culture medium into the injured part in the next day. At day 7, 14 and 28 after injection, we measured motor nerve conduction and detected mRNA expressions of netrin-1 receptors UNC5B and Deleted in Colorectal Cancer (DCC), and neurotrophic factors brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF) by real-time PCR. We also detected protein expressions of BDNF and NGF by Western blotting assays and examined BMSCs that incorporated into myelin and vascellum. The results showed that BMSCs infected by Ad5-Netrin-1-EGFP significantly improved the function of the sciatic nerve, and led to increased expression of BDNF and NGF (P<0.05). Moreover, 28 days after injury, more Schwann cells were found in BMSCs infected by Ad5-Netrin-1-EGFP compared to control BMSCs. In conclusion, transplantation of BMSCs that produce netrin-1 improved the function of the sciatic nerve after injury. This method may be a new treatment of nerve injury. PMID:26445571

  17. Changes of the different neuropeptide-containing nerve fibers and immunocells in the diabetic rat's alimentary tract.

    PubMed

    Fehér, Erzsébet; Batbayar, Bayarchimeg; Vér, Agota; Zelles, Tivadar

    2006-11-01

    Peripheral neuropathy is a common complication of diabetes mellitus, where neuropeptides and immunocells might play important roles in the pathogenesis of the disease. In this article we have quantified the different neuropeptide-containing nerve fibers and immunocells in the streptozotocin-induced diabetic rat's alimentary tract (tongue, duodenum, colon) using immunohistochemical and immunocytochemical methods. The immunoreactive (IR) nerve fibers were found in all layers of the alimentary tract and their distribution pattern was similar in both control and diabetic groups. Mast cell-nerve fiber contacts were rarely found in the controls. However, after 4 weeks duration of diabetes the number of IR nerve fibers and the immunocompetent cells increased significantly (P < 0.05), and the number of mast cell-nerve fiber contacts was even more significantly increased (P < 0.001). The distance between nerve fibers and immunocells was about 1 mum or even less. Some of the mast cells were degranulated in the vicinity of nerve fibers. No immunocompetent cells were IR for any antisera in the control. However, after the streptozotocin treatment, a large number of the immunocompetent cells showed immunoreactivity for SP and NPY. Counting all immunocompetent cells in whole sections showed that 12.3% of them were IR for SP and 25.4% were IR for NPY. Increased number of SP-containing nerve fibers and immunocells in diabetes mellitus might be the reason for painful neuropathy and might amplify the inflammatory reaction in an axon reflex manner; the released histamine and leukotrienes, cytokines, and chemokines might cause inflammations and lesions of the mucosa. PMID:17151308

  18. Persistent effects after trigeminal nerve proprioceptive stimulation by mandibular extension on rat blood pressure, heart rate and pial microcirculation.

    PubMed

    Lapi, D; Colantuoni, A; Del Seppia, C; Ghione, S; Tonlorenzi, D; Brunelli, M; Scuri, R

    2013-03-01

    The trigemino-cardiac reflex is a brainstem reflex known to lead to a decrement in heart rate and blood pressure, whereas few data have been collected about its effects on the cerebral hemodynamic. In this study we assess the in vivo effects of trigeminal nerve peripheral stimulation by mandibular extension on pial microcirculation and systemic arterial blood pressure in rats. Experiments were performed in male Wistar rats subjected to mandibular extension obtained inserting an ad hoc developed retractor between the dental arches. Mean arterial blood pressure and heart rate were recorded and the pial arterioles were visualized by fluorescence microscopy to measure the vessel diameters before (15 minutes) during (5-15 minutes) and after (80 minutes) mandibular extension. While in control rats (sham-operated rats) and in rats subjected to the dissection of the trigeminal peripheral branches mean arterial blood pressure, heart rate and pial microcirculation did not change during the whole observation period (110 minutes), in rats submitted to mandibular extension, mean arterial blood pressure, heart rate and arteriolar diameter significantly decreased during stimulation. Afterward mean arterial blood pressure remained reduced as well as heart rate, while arteriolar diameter significantly increased evidencing a vasodilatation persisting for the whole remaining observation time. Therefore, trigeminal nerve proprioceptive stimulation appears to trigger specific mechanisms regulating systemic arterial blood pressure and pial microcirculation. PMID:23807620

  19. Vagus Nerve Stimulation Reduces Body Weight and Fat Mass in Rats

    PubMed Central

    Banni, Sebastiano; Carta, Gianfranca; Murru, Elisabetta; Cordeddu, Lina; Giordano, Elena; Marrosu, Francesco; Puligheddu, Monica; Floris, Gabriele; Asuni, Gino Paolo; Cappai, Angela Letizia; Deriu, Silvia; Follesa, Paolo

    2012-01-01

    Among the manifold effects of vagus nerve stimulation (VNS) delivered as an add-on treatment to patients with drug-resistant epilepsy, a moderate loss of body weight has been observed in some individuals. We have now investigated this effect in rats. Exposure of rats to VNS for 4 weeks reduced feed conversion efficiency as well as body weight gain (by ∼25%) and the amount of mesenteric adipose tissue (by ∼45%) in comparison with those in sham-operated control animals. A pair-fed experiment showed that both lower dietary intake and increase energy expenditure independently contributed to the reduction of body weight and mesenteric adipose tissue. Moreover, VNS increased the level of non-esterified fatty acids in plasma and mesenteric adipose tissue by ∼50 and 80%, respectively, without affecting that in the liver. In addition, VNS reduced the amounts of endocannabinoids and increased N-palmitoylethanolamide, an endogenous ligand of the transcription factor PPARα (peroxisome proliferator–activated receptor α) in mesenteric adipose tissue but not in the hypothalamus. These effects were accompanied by increased expression of the gene for brain-derived neurotrophic factor (BDNF) in the hypothalamus and up-regulation of the abundance of PPARα in the liver. Our results suggest that the reduction in body fat induced by VNS in rats may result from the action of both central and peripheral mediators. The reduced feed conversion efficiency associated with VNS may be mediated by hypothalamic BDNF, down-regulation of endocannabinoid tone in mesenteric adipose tissue and a PPARα-dependent increase in fatty acid oxidation in the liver, which in concerted action may account for the anorexic effect and increased energy expenditure. PMID:23028630

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

    PubMed

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

    2015-09-01

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

  1. Electroacupuncture improves glucose tolerance through cholinergic nerve and nitric oxide synthase effects in rats.

    PubMed

    Lin, Rong-Tsung; Chen, Ching-Yuan; Tzeng, Chung-Yuh; Lee, Yu-Chen; Cheng, Yu-Wen; Chen, Ying-I; Ho, Wai-Jane; Cheng, Juei-Tang; Lin, Jaung-Geng; Chang, Shih-Liang

    2011-04-25

    The purpose of this investigation was to evaluate the effect and mechanisms of electroacupuncture (EA) at the bilateral Zusanli acupoints (ST-36) on glucose tolerance in normal rats. Intravenous glucose tolerance test (IVGTT) was performed to examine the effects of electroacupuncture (EA) on glucose tolerance in rats. The EA group underwent EA at the ST-36, with settings of 15 Hz, 10 mA, and 60 min; the control group underwent the same treatments, but without EA. Atropine, hemicholinium-3 (HC-3) or NG-nitro-L-arginine methyl ester (L-NAME) were injected into the rats alone or simultaneously and EA was performed to investigate differences in plasma glucose levels compared to the control group. Plasma samples were obtained for assaying plasma glucose and free fatty acid (FFA) levels. Western blot was done to determine the insulin signal protein and nNOS to exam the correlation between EA and improvement in glucose tolerance. The EA group had significantly lower plasma glucose levels compared to the control group. Plasma glucose levels differed significantly between the EA and control groups after the administration of L-NAME, atropine, or HC-3 treatments alone, but there were no significant differences in plasma glucose with combined treatment of L-NAME and atropine or L-NAME and HC-3. EA decreased FFA levels and enhanced insulin signal protein (IRS1) and nNOS activities in skeletal muscle during IVGTT. In summary, EA stimulated cholinergic nerves and nitric oxide synthase for lowering plasma FFA levels to improve glucose tolerance. PMID:21376780

  2. Direct conscious telemetry recordings demonstrate increased renal sympathetic nerve activity in rats with chronic kidney disease

    PubMed Central

    Salman, Ibrahim M.; Sarma Kandukuri, Divya; Harrison, Joanne L.; Hildreth, Cara M.; Phillips, Jacqueline K.

    2015-01-01

    Chronic kidney disease (CKD) is associated with sympathetic hyperactivity and impaired blood pressure control reflex responses, yet direct evidence demonstrating these features of autonomic dysfunction in conscious animals is still lacking. Here we measured renal sympathetic nerve activity (RSNA) and mean arterial pressure (MAP) using telemetry-based recordings in a rat model of CKD, the Lewis Polycystic Kidney (LPK) rat, and assessed responses to chemoreflex activation and acute stress. Male LPK and Lewis control animals (total n = 16) were instrumented for telemetric recording of RSNA and MAP. At 12–13 weeks-of-age, resting RSNA and MAP, sympathetic and haemodynamic responses to both peripheral (hypoxia: 10% O2) and central chemoreflex (hypercapnia: 7% CO2) activation and acute stress (open-field exposure), were measured. As indicators of renal function, urinary protein (UPro) and creatinine (UCr) levels were assessed. LPK rats had higher resting RSNA (1.2 ± 0.1 vs. 0.6 ± 0.1 μV, p < 0.05) and MAP (151 ± 8 vs. 97 ± 2 mmHg, p < 0.05) compared to Lewis. MAP was negatively correlated with UCr (r = −0.80, p = 0.002) and positively correlated with RSNA (r = 0.66, p = 0.014), with multiple linear regression modeling indicating the strongest correlation was with Ucr. RSNA and MAP responses to activation of the central chemoreflex and open-field stress were reduced in the LPK relative to the Lewis (all p < 0.05). This is the first description of dual conscious telemetry recording of RSNA and MAP in a genetic rodent model of CKD. Elevated RSNA is likely a key contributor to the marked hypertension in this model, while attenuated RSNA and MAP responses to central chemoreflex activation and acute stress in the LPK indicate possible deficits in the neural processing of autonomic outflows evoked by these sympathoexcitatory pathways. PMID:26300784

  3. Stretch-induced nerve injury: a proposed technique for the study of nerve regeneration and evaluation of the influence of gabapentin on this model

    PubMed Central

    Machado, J.A.; Ghizoni, M.F.; Bertelli, J.; Teske, Gabriel C.; Teske, Guilherme C.; Martins, D.F.; Mazzardo-Martins, L.; Cargnin-Ferreira, E.; Santos, A.R.S.; Piovezan, A.P.

    2013-01-01

    The rat models currently employed for studies of nerve regeneration present distinct disadvantages. We propose a new technique of stretch-induced nerve injury, used here to evaluate the influence of gabapentin (GBP) on nerve regeneration. Male Wistar rats (300 g; n=36) underwent surgery and exposure of the median nerve in the right forelimbs, either with or without nerve injury. The technique was performed using distal and proximal clamps separated by a distance of 2 cm and a sliding distance of 3 mm. The nerve was compressed and stretched for 5 s until the bands of Fontana disappeared. The animals were evaluated in relation to functional, biochemical and histological parameters. Stretching of the median nerve led to complete loss of motor function up to 12 days after the lesion (P<0.001), compared to non-injured nerves, as assessed in the grasping test. Grasping force in the nerve-injured animals did not return to control values up to 30 days after surgery (P<0.05). Nerve injury also caused an increase in the time of sensory recovery, as well as in the electrical and mechanical stimulation tests. Treatment of the animals with GBP promoted an improvement in the morphometric analysis of median nerve cross-sections compared with the operated vehicle group, as observed in the area of myelinated fibers or connective tissue (P<0.001), in the density of myelinated fibers/mm2 (P<0.05) and in the degeneration fragments (P<0.01). Stretch-induced nerve injury seems to be a simple and relevant model for evaluating nerve regeneration. PMID:24270909

  4. Peripheral vagus nerve stimulation significantly affects lipid composition and protein secondary structure within dopamine-related brain regions in rats.

    PubMed

    Surowka, Artur Dawid; Krygowska-Wajs, Anna; Ziomber, Agata; Thor, Piotr; Chrobak, Adrian Andrzej; Szczerbowska-Boruchowska, Magdalena

    2015-06-01

    Recent immunohistochemical studies point to the dorsal motor nucleus of the vagus nerve as the point of departure of initial changes which are related to the gradual pathological developments in the dopaminergic system. In the light of current investigations, it is likely that biochemical changes within the peripheral nervous system may influence the physiology of the dopaminergic system, suggesting a putative role for it in the development of neurodegenerative disorders. By using Fourier transform infrared microspectroscopy, coupled with statistical analysis, we examined the effect of chronic, unilateral electrical vagus nerve stimulation on changes in lipid composition and in protein secondary structure within dopamine-related brain structures in rats. It was found that the chronic vagal nerve stimulation strongly affects the chain length of fatty acids within the ventral tegmental area, nucleus accumbens, substantia nigra, striatum, dorsal motor nucleus of vagus and the motor cortex. In particular, the level of lipid unsaturation was found significantly increasing in the ventral tegmental area, substantia nigra and motor cortex as a result of vagal nerve stimulation. When it comes to changes in protein secondary structure, we could see that the mesolimbic, mesocortical and nigrostriatal dopaminergic pathways are particularly affected by vagus nerve stimulation. This is due to the co-occurrence of statistically significant changes in the content of non-ordered structure components, alpha helices, beta sheets, and the total area of Amide I. Macromolecular changes caused by peripheral vagus nerve stimulation may highlight a potential connection between the gastrointestinal system and the central nervous system in rat during the development of neurodegenerative disorders. PMID:25893743

  5. Up-regulated uridine kinase gene identified by RLCS in the ventral horn after crush injury to rat sciatic nerves.

    PubMed

    Yuh, I; Yaoi, T; Watanabe, S; Okajima, S; Hirasawa, Y; Fushiki, S

    1999-12-01

    Rat sciatic nerve crush injury is one of the models commonly employed for studying the mechanisms of nerve regeneration. In this study, we analyzed the temporal change of gene expression after injury in this model, to elucidate the molecular mechanisms involved in nerve regeneration. First, a cDNA analysis method, Restriction Landmark cDNA Scanning (RLCS), was applied to cells in the ventral horn of the spinal cord during a 7-day period after the crush injury. A total of 1991 cDNA species were detected as spots on gels, and 37 of these were shown to change after the injury. Temporally changed patterns were classified into three categories: the continuously up-regulated type (10 species), the transiently up-regulated type (22 species), and the down-regulated type (5 species). These complex patterns of gene expression demonstrated after the injury suggest that precise regulation in molecular pathways is required for accomplishing nerve regeneration. Secondly, the rat homologue of uridine kinase gene was identified as one of the up-regulated genes. Northern blot analysis on rat ventral horn tissue and brain revealed that the UK gene had three transcripts with different sizes (4.3, 1. 4, and 1.35 kb, respectively). All of the transcripts, especially the 4.3 kb one, were up-regulated mainly in a bimodal fashion during the 28-day period after the injury. The RLCS method that we employed in the present study shows promise as a means to fully analyze molecular changes in nerve regeneration in detail. PMID:10581173

  6. Effect of Dipsaci radix on hind limb muscle atrophy of sciatic nerve transected rats.

    PubMed

    Jung, Hyuk-Sang; Noh, Chung-Ku; Ma, Sun-Ho; Hong, Eun Ki; Sohn, Nak-Won; Kim, Yoon-Bum; Kim, Sung-Hoon; Sohn, Youngjoo

    2009-01-01

    It was reported that Dipsaci radix (DR) has a reinforcement effect on the bone-muscle dysfunction in the oriental medical classics and the experimental animal studies. The muscle atrophy was induced by unilateral transection of the sciatic nerve of the rats. Water-extract of DR was used as treatment once a day for 12 days. The muscle weights of the hind limb, atrophic changes, glycogen contents, compositions and cross-section areas of muscle fiber types in soleus and medial gastrocnemius were investigated. Muscle fiber type was classified to type-I and type-II with MHCf immunohistochemistry. Furthermore, Bax and Bcl-2 expressions were observed with immunohistochemiatry. DR treatment significantly increased muscle weights of soleus, medial gastrocnemius, lateral gastrocnemius, and posterior tibialis of the damaged hind limb. DR treatment reduced apoptotic muscle nuclei and hyaline-degenerated muscle fibers in soleus and medial gastrocnemius of the damaged hind limb. DR treatment also significantly increased glycogen contents in medial gastrocnemius of the damaged hind limb. DR treatment significantly attenuated the slow-to-fast shift in soleus of the damaged hind limb but not in medial gastrocnemius. DR treatment significantly increased cross-section areas of type-I and type-II fibers in soleus and medial gastrocnemius of the damaged hind limb. In soleus and medial gastrocnemius, DR treatment significantly reduced Bax positive muscle nuclei in the damaged hind limb. These results suggest that DR treatment has an anti-atrophic effect and an anti-apoptotic effect against myonuclear apoptosis induced by the peripheral nerve damage. PMID:19938217

  7. Motoneuron firing patterns underlying fast oscillations in phrenic nerve discharge in the rat

    PubMed Central

    Marchenko, Vitaliy; Ghali, Michael G. Z.

    2012-01-01

    Fast oscillations are ubiquitous throughout the mammalian central nervous system and are especially prominent in respiratory motor outputs, including the phrenic nerves (PhNs). Some investigators have argued for an epiphenomenological basis for PhN high-frequency oscillations because phrenic motoneurons (PhMNs) firing at these same frequencies have never been recorded, although their existence has never been tested systematically. Experiments were performed on 18 paralyzed, unanesthetized, decerebrate adult rats in which whole PhN and individual PhMN activity were recorded. A novel method for evaluating unit-nerve time-frequency coherence was applied to PhMN and PhN recordings. PhMNs were classified according to their maximal firing rate as high, medium, and low frequency, corresponding to the analogous bands in PhN spectra. For the first time, we report the existence of PhMNs firing at rates corresponding to high-frequency oscillations during eupneic motor output. The majority of PhMNs fired only during inspiration, but a small subpopulation possessed tonic activity throughout all phases of respiration. Significant time-varying PhMN-PhN coherence was observed for all PhMN classes. High-frequency, early-recruited units had significantly more consistent onset times than low-frequency, early/middle-recruited and medium-frequency, middle/late-recruited PhMNs. High- and medium-frequency PhMNs had significantly more consistent offset times than low-frequency units. This suggests that startup and termination of PhMNs with higher firing rates are more precisely controlled, which may contribute to the greater PhMN-PhN coherence at the beginning and end of inspiration. Our findings provide evidence that near-synchronous discharge of PhMNs firing at high rates may underlie fast oscillations in PhN discharge. PMID:22815408

  8. Optimal Vagus Nerve Stimulation Frequency for Suppression of Spike-and-Wave Seizures in Rats.

    PubMed

    Jiao, Jianhang; Harreby, Kristian R; Sevcencu, Cristian; Jensen, Winnie

    2016-06-01

    Vagus nerve stimulation (VNS) is used as an adjunctive therapy for drug-resistant epilepsy and results in a 50% seizure reduction in up to 50% of treated patients. The VNS frequency used in the clinic today is in the range of 10-30 Hz. The evidence for choosing the stimulation frequency is limited, and little knowledge is available on the effect of other VNS frequencies. Deep brain, trigeminal nerve, or spinal cord stimulation studies have suggested the use of stimulation frequencies above 80 Hz for seizure control. Therefore, our objective for the present study was to investigate if VNS using frequencies higher than those currently used in the clinic could be more effective in attenuating seizures. Spike-and-wave (SW) discharges were induced in 11 rats, which then were subjected to VNS sessions applied at the frequencies of 10, 30, 80, 130, and 180 Hz combined with control intervals without stimulation. The anticonvulsive effect of VNS was evaluated by comparing the normalized mean power (nMP) and frequency (nMSF) of the SW discharges derived from intracortical recordings collected during the stimulation and control intervals. Compared with the control intervals, all the tested VNS frequencies significantly reduced the nMP (in the range of 9-21%). However, we found that 130 and 180 Hz VNS induced a 50% larger attenuation of seizures than that achieved by 30 Hz VNS. In addition, we found that 80, 130, and 180 Hz VNS induced a significant reduction of the nMSF, that is by 5, 7, and 8%, respectively. These results suggest that a VNS stimulation frequency in the range of 130-180 Hz may be more effective in inhibiting seizures than the 30 Hz VNS applied in the clinic today. PMID:26713661

  9. Nerve Protective Effect of Asiaticoside against Ischemia-Hypoxia in Cultured Rat Cortex Neurons

    PubMed Central

    Sun, Tao; Liu, Bin; Li, Peng

    2015-01-01

    Background Asiaticoside is one of the main functional components of the natural plant Centella asiatica urban. Studies have reported it has several functions such as anti-depression and nerve cell protection. Asiaticoside can reduce the cerebral infarct size in acute focal cerebral ischemia in a mouse model and asiatic acid glycosides can significantly improve neurobehavioral scores. Currently, there is a lack of understanding of asiaticoside in regard to its neural protective mechanism in cerebral ischemia. This study aimed to solve this problem by using an ischemia-hypoxia cell model in vitro. Material/Methods An in vitro ischemia hypoxia cell model was successfully established by primary cultured newborn rat cortical neurons. After being treated by asiaticoside for 24 h, cell survival rate, lactate dehydrogenase release quantity, and B-cell lymphoma gene-2 (BCL-2), Bax, and caspase-3 protein expressions was detected. Results After 10 nmol/L or 100 nmol/L of asiaticoside were given to the cells, cell survival rate increased significantly and presented concentration dependence. Asiaticoside can reduce lactate dehydrogenase release. Lactate dehydrogenase release in model cells is gradually reduced with the increase of asiaticoside concentration. The lactate dehydrogenase release in asiaticoside 10 nmol/L group, asiaticoside 100 nmol/L group and ischemia hypoxia group were 26.75±1.05, 22.36±2.87 and 52.35±5.46%, respectively (p<0.05). It was also found that asiaticoside could modulate the expression of apoptotic factors, including bcl-2, Bax, and caspase-3. Conclusions Asiaticoside helps to protect in vitro ischemia hypoxia neurons. This nerve cell protection may be mediated by the BCL-2 protein. PMID:26447863

  10. Melatonin preserves superoxide dismutase activity in hypoglossal motoneurons of adult rats following peripheral nerve injury.

    PubMed

    Chang, Hung-Ming; Huang, Yi-Lun; Lan, Chyn-Tair; Wu, Un-In; Hu, Ming-E; Youn, Su-Chung

    2008-03-01

    Peripheral nerve injury (PNI) produces functional changes in lesioned neurons in which oxidative stress is considered to be the main cause of neuronal damage. As superoxide dismutase (SOD) is an important antioxidative enzyme involved in redox regulation of oxidative stress, the present study determined whether melatonin would exert its beneficial effects by preserving the SOD reactivity following PNI. Adult rats subjected to hypoglossal nerve transection were intraperitoneally injected with melatonin at ones for 3, 7, 14, 30 and 60 days successively. The potential neuroprotective effects of melatonin were quantitatively demonstrated by neuronal nitric oxide synthase (nNOS), mitochondrial manganese SOD (Mn-SOD), and cytosolic copper-zinc SOD (Cu/Zn-SOD) immunohistochemistry. The functional recovery of the lesioned neurons was evaluated by choline acetyltransferase (ChAT) immunohistochemistry along with the electromyographic (EMG) recordings of denervation-induced fibrillation activity. The results indicate that following PNI, the nNOS immunoreactivity was significantly increased in lesioned neurons peaking at 14 days. The up-regulation of nNOS temporally coincided with the reduction of ChAT and SOD in which the Cu/Zn-SOD showed a greater diminution than Mn-SOD. However, following melatonin administration, the nNOS augmentation was successfully suppressed and the activities of Mn-SOD, Cu/Zn-SOD, and ChAT were effectively preserved at all postaxotomy periods. EMG data also showed a decreased fibrillation in melatonin-treated groups, suggesting a potential effect of melatonin in promoting functional recovery. In association with its significant capacity in preserving SOD reactivity, melatonin is suggested to serve as a powerful therapeutic agent for treating PNI-relevant oxidative damage. PMID:18289169

  11. Effects of exogenous neurotrophin-3 on myocyte apoptosis and Ca2+-ATP enzyme levels following nerve injury in rats

    PubMed Central

    Dong, Yu-Zhen; Yang, Lin; Lu, Tan; Zhao, Hong-Xing; Ma, Chao; Zhao, Yi-Lei

    2015-01-01

    This study aims to determine the influence of neurotrophin-3 (NT-3) plasmids on neuronal apoptosis and Ca2+-ATP enzyme levels in injured muscles. We also investigated the mechanism underlying the role of NT-3 in delaying muscle atrophy following a peripheral nerve injury. Sixty adult Wistar rats were used to generate the peripheral nerve injury models. The rats were randomly assigned to the saline and NT-3 groups. Related indicators, such as caspase-3 protein expression, skeletal muscle cell apoptosis, and Ca2+-ATP enzyme expression were quantified. The expression levels of caspase-3 and the histone-muscle cell apoptosis rate in the NT-3 group decreased at different post-operative times following peripheral nerve injury, whereas NT-3 expression and the sarcoplasmic reticulum Ca2+-ATP enzyme levels increased. Statistically significant differences were observed in the NT-3 group as compared to the saline group (P < 0.05). NT-3 mitigated muscle atrophy following peripheral nerve damage by inhibiting caspase-3 gene expression and increasing Ca2+-ATP enzymatic activity, ultimately reducing muscle apoptosis. PMID:26770627

  12. Berberine Inhibits the Release of Glutamate in Nerve Terminals from Rat Cerebral Cortex

    PubMed Central

    Lu, Cheng-Wei; Huang, Shu-Kuei; Wang, Su-Jane

    2013-01-01

    Berberine, an isoquinoline plant alkaloid, protects neurons against neurotoxicity. An excessive release of glutamate is considered to be one of the molecular mechanisms of neuronal damage in several neurological diseases. In this study, we investigated whether berberine could affect endogenous glutamate release in nerve terminals of rat cerebral cortex (synaptosomes) and explored the possible mechanism. Berberine inhibited the release of glutamate evoked by the K+ channel blocker 4-aminopyridine (4-AP), and this phenomenon was prevented by the chelating extracellular Ca2+ ions and the vesicular transporter inhibitor bafilomycin A1, but was insensitive to the glutamate transporter inhibitor DL-threo-beta-benzyl-oxyaspartate. Inhibition of glutamate release by berberine was not due to it decreasing synaptosomal excitability, because berberine did not alter 4-AP-mediated depolarization. The inhibitory effect of berberine on glutamate release was associated with a reduction in the depolarization-induced increase in cytosolic free Ca2+ concentration. Involvement of the Cav2.1 (P/Q-type) channels in the berberine action was confirmed by blockade of the berberine-mediated inhibition of glutamate release by the Cav2.1 (P/Q-type) channel blocker ω-agatoxin IVA. In addition, the inhibitory effect of berberine on evoked glutamate release was prevented by the mitogen-activated/extracellular signal-regulated kinase kinase (MEK) inhibitors. Berberine decreased the 4-AP-induced phosphorylation of extracellular signal-regulated kinase 1 and 2 (ERK1/2) and synapsin I, the main presynaptic target of ERK; this decrease was also blocked by the MEK inhibition. Moreover, the inhibitory effect of berberine on evoked glutamate release was prevented in nerve terminals from mice lacking synapsin I. Together, these results indicated that berberine inhibits glutamate release from rats cortical synaptosomes, through the suppression of presynaptic Cav2.1 channels and ERK/synapsin I signaling

  13. Down-regulation of semaphorin 3F in rat retinal ganglion cells in response to optic nerve crush.

    PubMed

    Ko, Ji-Ae; Minamoto, Akira; Sugimoto, Yosuke; Kiuchi, Yoshiaki

    2016-07-01

    Glaucoma is characterized by degeneration of optic nerve axons and death of retinal ganglion cells (RGCs). Nerve crush and axotomy of the optic nerve are studied as models of RGC death in glaucoma and of axon regeneration. The mechanisms underlying the response of RGCs to axonal injury remain unclear, however. We have now examined the effects of optic nerve crush on the expression of members of the semaphorin family of neuronal guidance proteins in the rat retina. The expression of semaphorin 3F (Sema3F) in the retina was down-regulated at both the mRNA and protein levels at 7 days after optic nerve injury, whereas that of Sema3A, Sema3B or Sema3C remained unaffected. Immunohistofluorescence analysis and laser capture microdissection followed by reverse transcription-polymerase chain reaction analysis revealed that this loss of Sema3F expression occurred in the RGC layer of the retina. Furthermore, antibody-mediated neutralization of secreted Sema3F in retinal organ culture resulted in down-regulation of neuron-specific βIII-tubulin (Tuj-1 antigen), a marker of RGCs. Our results suggest that Sema3F may contribute to the regulation of RGC function or survival and therefore warrants further investigation as a potential mediator of neuroprotection. Copyright © 2016 John Wiley & Sons, Ltd. PMID:27309587

  14. Electron microscopic studies of macrophages in Wallerian degeneration of rat optic nerve after intravenous injection of colloidal carbon.

    PubMed Central

    Ling, E A

    1978-01-01

    The origin of macrophages in the degenerating optic nerve of rats after eye enucleation was investigated electron microscopically following intravenous labelling of mononuclear leucoytes with colloidal carbon. In the various post-operative periods studied carbon-labelled macrophages were seen at the site of lesion. At 4 and 7 days after enucleation carbon-labelled cells were seen at the site of Wallerian degeneration of the optic nerve over 4 mm distal to the site of the lesion. In the electron microscope these cells showed a flattened nucleus bearing coarse chromatin clumps, their cytoplasm contained a prominent Golgi complex and long isolate profiles of rough endoplasmic reticulum. Clusters of carbon particles in the cytoplasms were membrane-bound. Lysosomal bodies embedded with carbon particles were also observed. In relation to the blood vessels of the optic nerve, endothelial cells and pericytes with ingested carbon were seen. Macrophages in the meninges covering the optic nerve were also labelled. The results suggest that some macrophages in the region of Wallerian degeneration in the optic nerve, as well as those at the actual site of the lesion, were transformed blood leucocytes. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7 Fig. 8 Fig. 9 Fig. 10 Fig. 11 PMID:649492

  15. Sufficient virus-neutralizing antibody in the central nerve system improves the survival of rabid rats

    PubMed Central

    2012-01-01

    Background Rabies is known to be lethal in human. Treatment with passive immunity for the rabies is effective only when the patients have not shown the central nerve system (CNS) signs. The blood–brain barrier (BBB) is a complex functional barrier that may compromise the therapeutic development in neurological diseases. The goal of this study is to determine the change of BBB integrity and to assess the therapeutic possibility of enhancing BBB permeability combined with passive immunity in the late stage of rabies virus infection. Methods The integrity of BBB permeability in rats was measured by quantitative ELISA for total IgG and albumin levels in the cerebrospinal fluid (CSF) and by exogenously applying Evans blue as a tracer. Western blotting of occludin and ZO-1, two tight junction proteins, was used to assess the molecular change of BBB structure. The breakdown of BBB with hypertonic arabinose, recombinant tumor necrosis factor-alpha (rTNF-γ), and focused ultrasound (FUS) were used to compare the extent of BBB disruption with rabies virus infection. Specific humoral immunity was analyzed by immunofluorescent assay and rapid fluorescent focus inhibition test. Virus-neutralizing monoclonal antibody (mAb) 8-10E was administered to rats with hypertonic breakdown of BBB as a passive immunotherapy to prevent the death from rabies. Results The BBB permeability was altered on day 7 post-infection. Increased BBB permeability induced by rabies virus infection was observed primarily in the cerebellum and spinal cord. Occludin was significantly decreased in both the cerebral cortex and cerebellum. The rabies virus-specific antibody was not strongly elicited even in the presence of clinical signs. Disruption of BBB had no direct association with the lethal outcome of rabies. Passive immunotherapy with virus-neutralizing mAb 8-10E with the hypertonic breakdown of BBB prolonged the survival of rabies virus-infected rats. Conclusions We demonstrated that the BBB

  16. A New Preparation Method for Anisotropic Silk Fibroin Nerve Guidance Conduits and Its Evaluation In Vitro and in a Rat Sciatic Nerve Defect Model.

    PubMed

    Teuschl, Andreas Herbert; Schuh, Christina; Halbweis, Robert; Pajer, Krisztián; Márton, Gábor; Hopf, Rudolf; Mosia, Shorena; Rünzler, Dominik; Redl, Heinz; Nógrádi, Antal; Hausner, Thomas

    2015-09-01

    Over the past decade, silk fibroin (SF) has been emergently used in peripheral nerve tissue engineering. Current approaches aiming at producing SF-based nerve guidance conduits (SF-NGCs) used dissolved silk based on either aqueous solutions or organic solvents. In this study, we describe a novel procedure to produce SF-NGCs: A braided tubular structure of raw Bombyx mori silk is subsequently processed with the ternary solvent CaCl2/H2O/ethanol, formic acid, and methanol to improve its mechanical and topographical characteristics. Topographically, the combination of the treatments results in a fusion of the outer single silk fibers to a closed layer with a thickness ranging from about 40 to 75 μm. In contrast to the outer wall, the inner lumen (not treated with processing solvents) still represents the braided structure of single fibers. Mechanical stability, elasticity, and kink characteristics were evaluated with a custom-made test system. The modification procedure described here drastically improved the elastic properties of our tubular raw scaffold, favoring its use as a NGC. A cell migration assay with NIH/3T3-fibroblasts revealed the impermeability of the SF-NGC wall for possible invading and scar-forming cells. Moreover, the potential of the SF-NGC to serve as a substratum for Schwann cells has been demonstrated by cytotoxicity tests and live-dead stainings of Schwann cells grown on the inner surface of the SF-NGC. In vivo, the SF-NGC was tested in a rat sciatic nerve injury model. In short-term in vivo studies, it was proved that SF-NGCs are not triggering host inflammatory reactions. After 12 weeks, we could demonstrate morphological and functional reinnervation of the distal targets. Filled with collagen, a higher number of axons could be found in the distal to the graft (1678±303), compared with the empty SF-NGC (1274±146). The novel SF-NGC presented here shows promising results for the treatment of peripheral nerve injuries. The modification of

  17. Diet composition exacerbates or attenuates soman toxicity in rats: implied metabolic control of nerve agent toxicity.

    PubMed

    Myers, Todd M; Langston, Jeffrey L

    2011-06-01

    To evaluate the role of diet composition on nerve agent toxicity, rats were fed four distinct diets ad libitum for 28 d prior to challenge with 110 μg/kg (1.0 LD(50), sc) soman. The four diets used were a standard rodent diet, a choline-enriched diet, a glucose-enriched diet, and a ketogenic diet. Body weight was recorded throughout the study. Toxic signs and survival were evaluated at key times for up to 72 h following soman exposure. Additionally, acquisition of discriminated shuttlebox avoidance performance was characterized beginning 24h after soman challenge and across the next 8 d (six behavioral sessions). Prior to exposure, body weight was highest in the standard diet group and lowest in the ketogenic diet group. Upon exposure, differences in soman toxicity as a function of diet became apparent within the first hour, with mortality in the glucose-enriched diet group reaching 80% and exceeding all other groups (in which mortality ranged from 0 to 6%). At 72 h after exposure, mortality was 100% in the glucose-enriched diet group, and survival approximated 50% in the standard and choline-enriched diet groups, but equaled 87% in the ketogenic diet group. Body weight loss was significantly reduced in the ketogenic and choline-enriched diet groups, relative to the standard diet group. At 1 and 4h after exposure, rats in the ketogenic diet group had significantly lower toxic sign scores than all other groups. The ketogenic diet group performed significantly better than the standard diet group on two measures of active avoidance performance. The exacerbated soman toxicity observed in the glucose-enriched diet group coupled with the attenuated soman toxicity observed in the ketogenic diet group implicates glucose availability in the toxic effects of soman. This increased glucose availability may enhance acetylcholine synthesis and/or utilization, thereby exacerbating peripheral and central soman toxicity. PMID:21396400

  18. Vagus nerve electrical stimulation inhibits serum levels of S100A8 protein in septic shock rats.

    PubMed

    Lei, Ming; Liu, Xin-Xin

    2016-05-01

    The vagus nerve and the released acetylcholine exert anti-inflammatory effects and inhibit septic shock. However, their detailed mechanisms remain to be elucidated. The present study aimed to investigate the effects of vagus nerve electrical stimulation on serum S100A8 levels in septic shock rats. A total of 36 male Sprague-Dawley rats were randomly divided into six equal groups: i) Sham group, receiving sham operation; ii) CLP group, subjected to cecal ligation and puncture (CLP) to establish a model of polymicrobial sepsis; iii) VGX group, subjected to CLP and bilateral cervical vagotomy; iv) STM group, subjected to CLP, bilateral cervical vagotomy and electrical stimulation on the left vagus nerve trunk; v) α‑bungarotoxin (BGT) group was administered α‑BGT prior to electrical stimulation; vi) Anti‑receptor for advanced glycation end products (RAGE) group, administered intraperitoneal injection of anti‑RAGE antibody prior to electrical stimulation. The right carotid artery was cannulated to monitor mean artery pressure (MAP). The serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels were measured to assess the liver function. Serum S100A8 and advanced glycation end product (AGE) levels were measured using enzyme‑linked immunosorbent assays. The expression of hepatic RAGE was determined by western blotting. The present study revealed that Sprague‑Dawley rats exhibited progressive hypotension and significantly increased serum AST and ALT levels following CLP challenge compared with the sham group. The levels of S100A8 and AGEs, and the protein expression of hepatic RAGE were significantly increased following CLP compared with the sham group. Vagus nerve electrical stimulation significantly prevented the development of CLP‑induced hypotension, alleviated the hepatic damage, reduced serum S100A8 and AGEs production, and reduced the expression of hepatic RAGE. The inhibitory effect of vagus nerve electrical

  19. Nerve fibers that were not stained with the non-specific acetylcholinesterase (NsAchE) method, and TRPV1- and IB4-positive nerve fibers in the rat cornea.

    PubMed

    Nakagawa, Hiroshi; Hiura, Akio; Mitome, Masato; Ishimura, Kazunori

    2009-08-01

    Previously, we noticed the presence of nerve fiber-like structures in a whole mount preparation of the rat cornea that had not been stained with the non-specific acetylcholinesterase (NsAchE) method. These nerve-like fibers were projected into the central area of the cornea, forming a mesh-like pattern. The aim of this study is to examine the properties of these mesh-like fibers using the following two methods: their sensitivity to capsaicin and the detection of isolectin B4 (IB4)- and capsaicin receptor TRPV1 (transient receptor potential vanilloid 1)-reactivities. The mean disappeared area of non-stained fibers after NsAchE treatment was 26% of the total areas in the neonatally capsaicin-treated cornea. Bunches composed of fine IB4-positive nerve fibers were seen in a whole mount preparation. There were connections between the bunches, producing a mesh-like pattern similar to that of the fibers that were not stained with NsAchE. Fine TRPV1-immunoreactive (ir) nerve fibers were also shown to form bunches, with connections between each bunch observed in whole mount preparations. Thus, TRPV1-ir nerve fibers seem to densely innervate the rat corneal subepithelial stroma and are distinct from the NsAchE-positive nerve fibers. The TRPV1-ir fine nerve fibers overlapped with the IB4-positive nerve fibers, suggesting that the mesh-like fibers that were not stained with NsAchE are fine nociceptive sensory nerve fibers because of their sensitivity to capsaicin and similar distribution pattern to IB4- and TRPV1-positive nerve fibers. PMID:19763029

  20. Generation of New Neurons in Dorsal Root Ganglia in Adult Rats after Peripheral Nerve Crush Injury

    PubMed Central

    2015-01-01

    The evidence of neurons generated ex novo in sensory ganglia of adult animals is still debated. In the present study, we investigated, using high resolution light microscopy and stereological analysis, the changes in the number of neurons in dorsal root ganglia after 30 days from a crush lesion of the rat brachial plexus terminal branches. Results showed, as expected, a relevant hypertrophy of dorsal root ganglion neurons. In addition, we reported, for the first time in the literature, that neuronal hypertrophy was accompanied by massive neuronal hyperplasia leading to a 42% increase of the number of primary sensory neurons. Moreover, ultrastructural analyses on sensory neurons showed that there was not a relevant neuronal loss as a consequence of the nerve injury. The evidence of BrdU-immunopositive neurons and neural progenitors labeled with Ki67, nanog, nestin, and sox-2 confirmed the stereological evidence of posttraumatic neurogenesis in dorsal root ganglia. Analysis of morphological changes following axonal damage in addition to immunofluorescence characterization of cell phenotype suggested that the neuronal precursors which give rise to the newly generated neurons could be represented by satellite glial cells that actively proliferate after the lesion and are able to differentiate toward the neuronal lineage. PMID:25722894

  1. Essential Oil of Ocimum basilicum L. and (-)-Linalool Blocks the Excitability of Rat Sciatic Nerve.

    PubMed

    Medeiros Venancio, Antonio; Ferreira-da-Silva, Francisco Walber; da Silva-Alves, Kerly Shamyra; de Carvalho Pimentel, Hugo; Macêdo Lima, Matheus; Fraga de Santana, Michele; Barreto Alves, Péricles; Batista da Silva, Givanildo; Leal-Cardoso, José Henrique; Marchioro, Murilo

    2016-01-01

    The racemate linalool and its levogyrus enantiomer [(-)-LIN] are present in many essential oils and possess several pharmacological activities, such as antinociceptive and anti-inflammatory. In this work, the effects of essential oil obtained from the cultivation of the Ocimum basilicum L. (EOOb) derived from Germplasm Bank rich in (-)-LIN content in the excitability of peripheral nervous system were studied. We used rat sciatic nerve to investigate the EOOb and (-)-LIN effects on neuron excitability and the extracellular recording technique was used to register the compound action potential (CAP). EOOb and (-)-LIN blocked the CAP in a concentration-dependent way and these effects were reversible after washout. EOOb blocked positive amplitude of 1st and 2nd CAP components with IC50 of 0.38 ± 0.2 and 0.17 ± 0.0 mg/mL, respectively. For (-)-LIN, these values were 0.23 ± 0.0 and 0.13 ± 0.0 mg/mL. Both components reduced the conduction velocity of CAP and the 2nd component seems to be more affected than the 1st component. In conclusion EOOb and (-)-LIN inhibited the excitability of peripheral nervous system in a similar way and potency, revealing that the effects of EOOb on excitability are due to the presence of (-)-LIN in the essential oil. PMID:27446227

  2. Elevated Neurosteroids in the Lateral Thalamus Relieve Neuropathic Pain in Rats with Spared Nerve Injury.

    PubMed

    Zhang, Meng; Liu, Jia; Zhou, Meng-Meng; Wu, Honghai; Hou, Yanning; Li, Yun-Feng; Yin, Yuxin; Zheng, Lemin; Liu, Feng-Yu; Yi, Ming; Wan, You

    2016-08-01

    Neurosteroids are synthesized in the nervous system from cholesterol or steroidal precursors imported from peripheral sources. These compounds are important allosteric modulators of γ-aminobutyric acid A receptors (GABAARs), which play a vital role in pain modulation in the lateral thalamus, a main gate where somatosensory information enters the cerebral cortex. Using high-performance liquid chromatography/tandem mass spectrometry, we found increased levels of neurosteroids (pregnenolone, progesterone, deoxycorticosterone, allopregnanolone, and tetrahydrodeoxycorticosterone) in the chronic stage of neuropathic pain (28 days after spared nerve injury) in rats. The expression of the translocator protein TSPO, the upstream steroidogenesis rate-limiting enzyme, increased at the same time. In vivo stereotaxic microinjection of neurosteroids or the TSPO activator AC-5216 into the lateral thalamus (AP -3.0 mm, ML ±3.0 mm, DV 6.0 mm) alleviated the mechanical allodynia in neuropathic pain, while the TSPO inhibitor PK 11195 exacerbated it. The analgesic effects of AC-5216 and neurosteroids were significantly attenuated by the GABAAR antagonist bicuculline. These results suggested that elevated neurosteroids in the lateral thalamus play a protective role in the chronic stage of neuropathic pain. PMID:27325509

  3. Lead (Pb) alters the norepinephrine-induced secretion of luteinizing hormone releasing hormone from the median eminence of adult male rats in vitro

    SciTech Connect

    Bratton, G.R.; Hiney, J.K.; Dees, W.L. )

    1994-01-01

    In the present study, the authors evaluated the in vitro effects of lead (Pb) on basal and stimulated luteinizing hormone releasing hormone (LHRH) and Prostaglandin E[sub 2] (PGE[sub 2]) secretion. Median eminences (ME) were removed from brains of adult male rats and preincubated for 15 minutes in Krebs-Ringer bicarbonate glucose buffer in an atmosphere of 95% O[sub 2]-5% CO[sub 2]. These media were discarded and all MEs were subjected to one of the following experiments. In Experiment 1, all MEs were incubated for 30 minutes in medium only. These media were collected and replaced with medium only (controls) or with medium containing Pb doses ranging from 5 to 20 [mu]M. After this 60-minute incubation, media were collected, then replaced with new medium containing 60 [mu]M norepinephrine (NE), or NE plus each dose of Pb, then incubated for a final 30-minute period. Experiment 2 was conducted as above, except PGE[sub 2] (2.8 [mu]M) replaced the NE. In both experiments, the amounts of LHRH released was measured by RIA. In experiment 3, NE was again used for the challenge; however, this time, the amount of PGE[sub 2] released was measured by RIA. Results indicate that Pb did not alter basal LHRH release, but compared with controls, significantly blocked NE-induced LHRH release in a dose-related manner. Conversely, Pb had no effect on the PGE[sub 2]-induced release of LHRH. Additionally, Pb did not alter basal PGE[sub 2] release; however, it significantly blocked the NE-induced release of PGE[sub 2]. Since NE-induced LHRH release is mediated by PGE[sub 2], these results support the hypothesis that Pb is capable of altering the hypothalamus and suggest that this effect is due, at least in part, to the diminished PGE[sub 2] synthesis/release within the ME, resulting in diminished LHRH secretion.

  4. Hybrid electro-optical stimulation of the rat sciatic nerve induces force generation in the plantarflexor muscles

    NASA Astrophysics Data System (ADS)

    Duke, Austin R.; Peterson, Erik; Mackanos, Mark A.; Atkinson, James; Tyler, Dustin; Jansen, E. Duco

    2012-12-01

    Objective. Optical methods of neural activation are becoming important tools for the study and treatment of neurological disorders. Infrared nerve stimulation (INS) is an optical technique exhibiting spatially precise activation in the native neural system. While this technique shows great promise, the risk of thermal damage may limit some applications. Combining INS with traditional electrical stimulation, a method known as hybrid electro-optical stimulation, reduces the laser power requirements and mitigates the risk of thermal damage while maintaining spatial selectivity. Here we investigate the capability of inducing force generation in the rat hind limb through hybrid stimulation of the sciatic nerve. Approach. Hybrid stimulation was achieved by combining an optically transparent nerve cuff for electrical stimulation and a diode laser coupled to an optical fiber for infrared stimulation. Force generation in the rat plantarflexor muscles was measured in response to hybrid stimulation with 1 s bursts of pulses at 15 and 20 Hz and with a burst frequency of 0.5 Hz. Main results. Forces were found to increase with successive stimulus trains, ultimately reaching a plateau by the 20th train. Hybrid evoked forces decayed at a rate similar to the rate of thermal diffusion in tissue. Preconditioning the nerve with an optical stimulus resulted in an increase in the force response to both electrical and hybrid stimulation. Histological evaluation showed no signs of thermally induced morphological changes following hybrid stimulation. Our results indicate that an increase in baseline temperature is a likely contributor to hybrid force generation. Significance. Extraneural INS of peripheral nerves at physiologically relevant repetition rates is possible using hybrid electro-optical stimulation.

  5. Dexamethasone and vitamin B12 synergistically promote peripheral nerve regeneration in rats by upregulating the expression of brain-derived neurotrophic factor

    PubMed Central

    Sun, Hongzhi; Yang, Tao; Li, Qing; Zhu, Zhitu; Wang, Lei; Bai, Guang; Li, Dongsheng; Li, Qiang

    2012-01-01

    Introduction Dexamethasone and vitamin B12 are currently used in the clinic to treat peripheral nerve damage but their mechanisms of action remain incompletely understood. In this study we hypothesized that dexamethasone and vitamin B12 promote the production of endogenous neurotrophic factors, thereby enhancing peripheral nerve repair. Material and methods Ninety-six adult male Wistar rats were employed to establish a sciatic nerve injury model. They were then randomly divided into 4 groups to be subjected to different treatment: saline (group A), dexamethasone (group B), vitamin B12 (group C), and dexamethasone combined with vitamin B12 (group D). The walking behavior of rats was evaluated by footprint analysis, and the nerve regeneration was assessed by electrophysiological analysis and ultrastructural examination. The expression of brain-derived neurotrophic factor (BDNF), glial cell-derived neurotrophic factor, NT-3 and IL-6 in the injured sciatic nerves was detected by immunohistochemical and RT-PCR analysis. Results Dexamethasone and vitamin B12 promoted the regeneration of myelinated nerve fibers and the proliferation of Schwann cells. Furthermore, dexamethasone and vitamin B12 promoted the recovery of sciatic functional index and sensory nerve conduction velocity, and upregulated BDNF expression in the injured sciatic nerves. Conclusions Dexamethasone and vitamin B12 promote peripheral nerve repair in a rat model of sciatic nerve injury through the upregulation of BDNF expression. These findings provide new insight into the neurotrophic effects of dexamethasone and vitamin B12 and support the application of these agents in clinical treatment of peripheral nerve injury. PMID:23185205

  6. ELECTRICAL STIMULATION OF THE VAGUS NERVE DERMATOME IN THE EXTERNAL EAR IS PROTECTIVE IN RAT CEREBRAL ISCHEMIA

    PubMed Central

    Ay, Ilknur; Napadow, Vitaly; Ay, Hakan

    2014-01-01

    Background Although cervical vagus nerve stimulation is effective for reducing infarct volume in rats, it is not feasible for acute human stroke as it requires surgical incision of the neck. We hypothesized that stimulation of the dermatome in the external ear innervated by the vagus nerve (auricular vagus nerve stimulation; aVNS) reduces infarct volume after transient focal ischemia in rats. Methods Animals were randomized to active aVNS or sham stimulation. For aVNS, electrical stimulation of the left cavum concha (1 hour duration) using percutaneous needles was initiated 30 min after induction of ischemia. Behavioral and tissue outcome were measured 24 hours after induction of ischemia. In a separate experimental dataset, c-Fos immunohistochemistry was performed to identify the brain regions activated after the stimulation. Results Stimulation of the left cavum concha resulted in bilateral c-Fos staining in the nuclei tractus solitarii and the loci coerulei in all animals. There was no c-Fos staining in any part of the brainstem in sham control animals. The mean infarct volume (SD) as calculated by indirect method was 44.20 ± 7.58% in controls and 31.65 ± 9.67% in treated animals (p<0.0001). The effect of aVNS on tissue outcome was associated with better neurological scores at 24 hours after ischemia (p<0.0001). Conclusions Electric stimulation of the vagus nerve dermatome in the external ear activates brainstem afferent vagal nuclei and reduces infarct volume in rats. This finding has potential to facilitate the development of treatments that leverage the brain’s endogenous neuroprotective pathways at the setting of acute ischemic stroke. PMID:25312600

  7. Engrafted Human Induced Pluripotent Stem Cell-Derived Anterior Specified Neural Progenitors Protect the Rat Crushed Optic Nerve

    PubMed Central

    Satarian, Leila; Javan, Mohammad; Kiani, Sahar; Hajikaram, Maryam; Mirnajafi-Zadeh, Javad; Baharvand, Hossein

    2013-01-01

    Background Degeneration of retinal ganglion cells (RGCs) is a common occurrence in several eye diseases. This study examined the functional improvement and protection of host RGCs in addition to the survival, integration and neuronal differentiation capabilities of anterior specified neural progenitors (NPs) following intravitreal transplantation. Methodology/Principal Findings NPs were produced under defined conditions from human induced pluripotent stem cells (hiPSCs) and transplanted into rats whose optic nerves have been crushed (ONC). hiPSCs were induced to differentiate into anterior specified NPs by the use of Noggin and retinoic acid. The hiPSC-NPs were labeled by green fluorescent protein or a fluorescent tracer 1,1′ -dioctadecyl-3,3,3′,3′-tetramethylindocarbocyanine perchlorate (DiI) and injected two days after induction of ONC in hooded rats. Functional analysis according to visual evoked potential recordings showed significant amplitude recovery in animals transplanted with hiPSC-NPs. Retrograde labeling by an intra-collicular DiI injection showed significantly higher numbers of RGCs and spared axons in ONC rats treated with hiPSC-NPs or their conditioned medium (CM). The analysis of CM of hiPSC-NPs showed the secretion of ciliary neurotrophic factor, basic fibroblast growth factor, and insulin-like growth factor. Optic nerve of cell transplanted groups also had increased GAP43 immunoreactivity and myelin staining by FluoroMyelin™ which imply for protection of axons and myelin. At 60 days post-transplantation hiPSC-NPs were integrated into the ganglion cell layer of the retina and expressed neuronal markers. Conclusions/Significance The transplantation of anterior specified NPs may improve optic nerve injury through neuroprotection and differentiation into neuronal lineages. These NPs possibly provide a promising new therapeutic approach for traumatic optic nerve injuries and loss of RGCs caused by other diseases. PMID:23977164

  8. Hispidulin inhibits the release of glutamate in rat cerebrocortical nerve terminals

    SciTech Connect

    Lin, Tzu-Yu; Lu, Cheng-Wei; Wang, Chia-Chuan; Lu, Jyh-Feng; Wang, Su-Jane

    2012-09-01

    Hispidulin, a naturally occurring flavone, has been reported to have an antiepileptic profile. An excessive release of glutamate is considered to be related to neuropathology of epilepsy. We investigated whether hispidulin affected endogenous glutamate release in rat cerebral cortex nerve terminals (synaptosomes) and explored the possible mechanism. Hispidulin inhibited the release of glutamate evoked by the K{sup +} channel blocker 4-aminopyridine (4-AP). The effects of hispidulin on the evoked glutamate release were prevented by the chelation of extracellular Ca{sup 2+} ions and the vesicular transporter inhibitor bafilomycin A1. However, the glutamate transporter inhibitor DL-threo-beta-benzyl-oxyaspartate did not have any effect on hispidulin action. Hispidulin reduced the depolarization-induced increase in cytosolic free Ca{sup 2+} concentration ([Ca{sup 2+}]{sub C}), but did not alter 4-AP-mediated depolarization. Furthermore, the effect of hispidulin on evoked glutamate release was abolished by blocking the Ca{sub v}2.2 (N-type) and Ca{sub v}2.1 (P/Q-type) channels, but not by blocking ryanodine receptors or mitochondrial Na{sup +}/Ca{sup 2+} exchange. Mitogen-activated protein kinase kinase (MEK) inhibition also prevented the inhibitory effect of hispidulin on evoked glutamate release. Western blot analyses showed that hispidulin decreased the 4-AP-induced phosphorylation of extracellular signal-regulated kinase 1 and 2 (ERK1/2) and synaptic vesicle-associated protein synapsin I, a major presynaptic substrate for ERK; this decrease was also blocked by the MEK inhibitor. Moreover, the inhibition of glutamate release by hispidulin was strongly attenuated in mice without synapsin I. These results show that hispidulin inhibits glutamate release from cortical synaptosomes in rats through the suppression of presynaptic voltage-dependent Ca{sup 2+} entry and ERK/synapsin I signaling pathway. -- Highlights: ► Hispidulin inhibited glutamate release from rat

  9. Subsurface optical stimulation of the rat prostate nerves using continuous-wave near-infrared laser radiation

    NASA Astrophysics Data System (ADS)

    Tozburun, Serhat; Lagoda, Gwen A.; Burnett, Arthur L.; Fried, Nathaniel M.

    2012-02-01

    Successful identification and preservation of the cavernous nerves (CN), which are responsible for sexual function, during prostate cancer surgery, will require subsurface detection of the CN beneath a thin fascia layer. This study explores optical nerve stimulation (ONS) in the rat with a fascia layer placed over the CN. Two near-IR diode lasers (1455 nm and 1550 nm lasers) were used to stimulate the CN in CW mode with a 1-mm-diameter spot in 8 rats. The 1455 nm wavelength provides an optical penetration depth (OPD) of ~350 μm, while 1550 nm provides an OPD of ~1000 μm (~3 times deeper than 1455 nm and 1870 nm wavelengths previously tested). Fascia layers with thicknesses of 85 - 600 μm were placed over the CN. Successful ONS was confirmed by an intracavernous pressure (ICP) response in the rat penis at 1455 nm through fascia 110 μm thick and at 1550 nm through fascia 450 μm thick. Higher incident laser power was necessary and weaker and slower ICP responses were observed as fascia thickness was increased. Subsurface ONS of the rat CN at a depth of 450 μm using a 1550 nm laser is feasible.

  10. Sensory nerve endings in the rat oro-facial region labeled by the anterograde and transganglionic transport of horseradish peroxidase: a new method for tracing peripheral nerve fibers.

    PubMed

    Marfurt, C F; Turner, D F

    1983-02-14

    The purpose of the present investigation is to introduce the enzyme horseradish peroxidase (HRP) for the study of the morphology and peripheral distribution of sensory nerve endings. HRP was injected into the trigeminal ganglion or trigeminal brainstem nuclear complex (TBNC) in separate adult rats. HRP injected into the trigeminal ganglion was taken up by the neuronal perikarya and transported anterogradely in massive amounts to sensory nerve endings in the cornea, vibrissal hair follicles, tooth pulps, and periodontal ligaments. HRP injected into the TBNC was taken up by trigeminal primary afferent fibers that terminated there and transported transganglionically, i.e., past or through the trigeminal ganglion, to peripheral sensory endings. The results of the present study demonstrate for the first time that: (1) anterograde HRP transport is a highly successful method of labeling with an intracellular marker trigeminal sensory endings in a variety of oro-facial tissues, and (2) trigeminal primary sensory neurons possess intra-axonal transport mechanisms by which HRP, and possibly other substances, taken up in the central nervous system may be transported to the periphery. PMID:6601506

  11. Behavioral and cellular consequences of high-electrode count Utah Arrays chronically implanted in rat sciatic nerve

    NASA Astrophysics Data System (ADS)

    Wark, H. A. C.; Mathews, K. S.; Normann, R. A.; Fernandez, E.

    2014-08-01

    Objective. Before peripheral nerve electrodes can be used for the restoration of sensory and motor functions in patients with neurological disorders, the behavioral and histological consequences of these devices must be investigated. These indices of biocompatibility can be defined in terms of desired functional outcomes; for example, a device may be considered for use as a therapeutic intervention if the implanted subject retains functional neurons post-implantation even in the presence of a foreign body response. The consequences of an indwelling device may remain localized to cellular responses at the device-tissue interface, such as fibrotic encapsulation of the device, or they may affect the animal more globally, such as impacting behavioral or sensorimotor functions. The objective of this study was to investigate the overall consequences of implantation of high-electrode count intrafascicular peripheral nerve arrays, High Density Utah Slanted Electrode Arrays (HD-USEAs; 25 electrodes mm-2). Approach. HD-USEAs were implanted in rat sciatic nerves for one and two month periods. We monitored wheel running, noxious sensory paw withdrawal reflexes, footprints, nerve morphology and macrophage presence at the tissue-device interface. In addition, we used a novel approach to contain the arrays in actively behaving animals that consisted of an organic nerve wrap. A total of 500 electrodes were implanted across all ten animals. Main results. The results demonstrated that chronic implantation (⩽8 weeks) of HD-USEAs into peripheral nerves can evoke behavioral deficits that recover over time. Morphology of the nerve distal to the implantation site showed variable signs of nerve fiber degeneration and regeneration. Cytology adjacent to the device-tissue interface also showed a variable response, with some electrodes having many macrophages surrounding the electrodes, while other electrodes had few or no macrophages present. This variability was also seen along the length

  12. MORPHOMETRIC AND ELECTROPHYSIOLOGICAL EVIDENCE FOR A DIAMETER-BASED RATE OF DEGENERATION IN THE OPTIC NERVE OF THE RAT (JOURNAL VERSION)

    EPA Science Inventory

    The diameter-based rate of degeneration in the rat's optic nerve was examined using coordinated morphological and electrophysiological techniques. Long-Evans male rats were implanted with indwelling stimulating electrodes in the optic chiasm and recording electrodes in the stratu...

  13. Nitric oxide modulates bladder afferent nerve activity in the in vitro urinary bladder-pelvic nerve preparation from rats with cyclophosphamide induced cystitis.

    PubMed

    Yu, Yongbei; de Groat, William C

    2013-01-15

    Effects of a nitric oxide (NO) donor (SNAP), NO substrate (l-arginine), and NO synthase inhibitor (l-NAME) on bladder afferent nerve (BAN) activity were studied in an in vitro bladder-pelvic nerve preparation from untreated or cyclophosphamide (CYP) treated rats. Distension of the bladder induced phasic bladder contractions (PBC) that were accompanied by multiunit afferent firing. Intravesical administration of SNAP (2mM) which did not change the amplitude of PBC significantly decreased peak afferent firing from 79 ± 15 spikes/s to 44 ± 8 spikes/s in CYP pretreated but not untreated preparations. In CYP treated preparations SNAP also decreased by 33-55% BAN firing induced by isotonic distension of the bladder at 10-40 cmH(2)O pressures. Electrical stimulation on the surface of the bladder elicited action potentials (AP) in BAN. SNAP significantly increased the voltage threshold by 75% (p<0.05) and decreased by 45% (p<0.05) the area of the AP evoked at submaximal stimulus intensity. Bath application of SNAP (2mM) or l-arginine (50mM) elicited similar inhibitory effects on the distension evoked BAN firing. The effects of l-arginine were blocked by bath application of l-NAME (20mM). l-NAME alone did not alter BAN firing. In preparations from normal rats SNAP or l-arginine did not alter BAN activity. These results suggest that exogenous as well as endogenously generated NO depresses the excitability of sensitized but not normal BAN and that NO may have an antinociceptive function and modulate bladder hyperactivity induced by pathological conditions. PMID:23063886

  14. Targeted NGF siRNA Delivery Attenuates Sympathetic Nerve Sprouting and Deteriorates Cardiac Dysfunction in Rats with Myocardial Infarction

    PubMed Central

    Wang, Ye; Xue, Mei; Suo, Fei; Li, Xiaolu; Cheng, Wenjuan; Li, Xinran; Yin, Jie; Liu, Ju; Yan, Suhua

    2014-01-01