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  1. Changes in ganglion cells during retinal degeneration.

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    Saha, Susmita; Greferath, Ursula; Vessey, Kirstan A; Grayden, David B; Burkitt, Anthony N; Fletcher, Erica L

    2016-08-04

    Inherited retinal degeneration such as retinitis pigmentosa (RP) is associated with photoreceptor loss and concomitant morphological and functional changes in the inner retina. It is not known whether these changes are associated with changes in the density and distribution of synaptic inputs to retinal ganglion cells (RGCs). We quantified changes in ganglion cell density in rd1 and age-matched C57BL/6J-(wildtype, WT) mice using the immunocytochemical marker, RBPMS. Our data revealed that following complete loss of photoreceptors, (∼3months of age), there was a reduction in ganglion cell density in the peripheral retina. We next examined changes in synaptic inputs to A type ganglion cells by performing double labeling experiments in mice with the ganglion cell reporter lines, rd1-Thy1 and age-matched wildtype-Thy1. Ribbon synapses were identified by co-labelling with CtBP2 (RIBEYE) and conventional synapses with the clustering molecule, gephyrin. ON RGCs showed a significant reduction in RIBEYE-immunoreactive synapse density while OFF RGCs showed a significant reduction in the gephyrin-immmunoreactive synapse density. Distribution patterns of both synaptic markers across the dendritic trees of RGCs were unchanged. The change in synaptic inputs to RGCs was associated with a reduction in the number of immunolabeled rod bipolar and ON cone bipolar cells. These results suggest that functional changes reported in ganglion cells during retinal degeneration could be attributed to loss of synaptic inputs. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

  2. Brimonidine prevents axonal and somatic degeneration of retinal ganglion cell neurons

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    Crish Samuel D

    2011-01-01

    Full Text Available Abstract Background Brimonidine is a common drug for lowering ocular pressure and may directly protect retinal ganglion cells in glaucoma. The disease involves early loss of retinal ganglion cell transport to brain targets followed by axonal and somatic degeneration. We examined whether brimonidine preserves ganglion cell axonal transport and abates degeneration in rats with elevated ocular pressure induced by laser cauterization of the episcleral veins. Results Ocular pressure was elevated unilaterally by 90% for a period of 8 weeks post- cauterization. During this time, brimonidine (1mg/kg/day or vehicle (phosphate-buffered saline was delivered systemically and continuously via subcutaneous pump. Animals received bilateral intravitreal injections of fluorescent cholera toxin subunit β (CTB two days before sacrifice to assess anterograde transport. In retinas from the vehicle group, elevated pressure induced a 44% decrease in the fraction of ganglion cells with intact uptake of CTB and a 14-42% reduction in the number of immuno-labelled ganglion cell bodies, with the worst loss occurring nasally. Elevated pressure also caused a 33% loss of ganglion cell axons in vehicle optic nerves and a 70% decrease in CTB transport to the superior colliculus. Each of these components of ganglion cell degeneration was either prevented or significantly reduced in the brimonidine treatment group. Conclusions Continuous and systemic treatment with brimonidine by subcutaneous injection significantly improved retinal ganglion cell survival with exposure to elevated ocular pressure. This effect was most striking in the nasal region of the retina. Brimonidine treatment also preserved ganglion cell axon morphology, sampling density and total number in the optic nerve with elevated pressure. Consistent with improved outcome in the optic projection, brimonidine also significantly reduced the deficits in axonal transport to the superior colliculus associated with

  3. Taurine Provides Neuroprotection against Retinal Ganglion Cell Degeneration

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    Froger, Nicolas; Cadetti, Lucia; Lorach, Henri; Martins, Joao; Bemelmans, Alexis-Pierre; Dubus, Elisabeth; Degardin, Julie; Pain, Dorothée; Forster, Valérie; Chicaud, Laurent; Ivkovic, Ivana; Simonutti, Manuel; Fouquet, Stéphane; Jammoul, Firas; Léveillard, Thierry; Benosman, Ryad; Sahel, José-Alain; Picaud, Serge

    2012-01-01

    Retinal ganglion cell (RGC) degeneration occurs in numerous retinal diseases leading to blindness, either as a primary process like in glaucoma, or secondary to photoreceptor loss. However, no commercial drug is yet directly targeting RGCs for their neuroprotection. In the 70s, taurine, a small sulfonic acid provided by nutrition, was found to be essential for the survival of photoreceptors, but this dependence was not related to any retinal disease. More recently, taurine deprivation was incriminated in the retinal toxicity of an antiepileptic drug. We demonstrate here that taurine can improve RGC survival in culture or in different animal models of RGC degeneration. Taurine effect on RGC survival was assessed in vitro on primary pure RCG cultures under serum-deprivation conditions, and on NMDA-treated retinal explants from adult rats. In vivo, taurine was administered through the drinking water in two glaucomatous animal models (DBA/2J mice and rats with vein occlusion) and in a model of Retinitis pigmentosa with secondary RGC degeneration (P23H rats). After a 6-day incubation, 1 mM taurine significantly enhanced RGCs survival (+68%), whereas control RGCs were cultured in a taurine-free medium, containing all natural amino-acids. This effect was found to rely on taurine-uptake by RGCs. Furthermore taurine (1 mM) partly prevented NMDA-induced RGC excitotoxicity. Finally, taurine supplementation increased RGC densities both in DBA/2J mice, in rats with vein occlusion and in P23H rats by contrast to controls drinking taurine-free water. This study indicates that enriched taurine nutrition can directly promote RGC survival through RGC intracellular pathways. It provides evidence that taurine can positively interfere with retinal degenerative diseases. PMID:23115615

  4. Expression of EFR3A in the mouse cochlea during degeneration of spiral ganglion following hair cell loss.

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    Chen Nie

    Full Text Available Retrograde degeneration of spiral ganglion cells in the cochlea following hair cell loss is similar to dying back in pathology. The EFR3A gene has recently been discovered to be involved in the pathogenesis of dying back. The relationship of EFR3A and spiral ganglion degeneration, however, was rarely investigated. In this study, we destroyed the hair cells of the mouse cochlea by co-administration of kanamycin and furosemide and then investigated the EFR3A expression during the induced spiral ganglion cell degeneration. Our results revealed that co-administration of kanamycin and furosemide quickly induced hair cell loss in the C57BL/6J mice and then resulted in progressive degeneration of the spiral ganglion beginning at day 5 following drug administration. The number of the spiral ganglion cells began to decrease at day 15. The expression of EFR3A increased remarkably in the spiral ganglion at day 5 and then decreased to near normal level within the next 10 days. Our study suggested that the change of EFR3A expression in the spiral ganglion was coincident with the time of the spiral ganglion degeneration, which implied that high expression of EFR3A may be important to prompt initiation of spiral ganglion degeneration following hair cell loss.

  5. Changes in ganglion cell physiology during retinal degeneration influence excitability by prosthetic electrodes

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    Cho, Alice; Ratliff, Charles; Sampath, Alapakkam; Weiland, James

    2016-04-01

    Objective. Here we investigate ganglion cell physiology in healthy and degenerating retina to test its influence on threshold to electrical stimulation. Approach. Age-related Macular Degeneration and Retinitis Pigmentosa cause blindness via outer retinal degeneration. Inner retinal pathways that transmit visual information to the central brain remain intact, so direct electrical stimulation from prosthetic devices offers the possibility for visual restoration. Since inner retinal physiology changes during degeneration, we characterize physiological properties and responses to electrical stimulation in retinal ganglion cells (RGCs) of both wild type mice and the rd10 mouse model of retinal degeneration. Main results. Our aggregate results support previous observations that elevated thresholds characterize diseased retinas. However, a physiology-driven classification scheme reveals distinct sub-populations of ganglion cells with thresholds either normal or strongly elevated compared to wild-type. When these populations are combined, only a weakly elevated threshold with large variance is observed. The cells with normal threshold are more depolarized at rest and exhibit periodic oscillations. Significance. During degeneration, physiological changes in RGCs affect the threshold stimulation currents required to evoke action potentials.

  6. Degeneration and regeneration in the superior cervical sympathetic ganglion after Latrodectus venom.

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    Daniel, S E

    1989-06-01

    The effects of the venom of the spider Latrodectus mactans hasselti on the superior cervical ganglion were studied in the guinea pig. Under anaesthesia the ganglion was bathed in venom solution for 15 min. Shortly afterwards animals salivated profusely and later developed unilateral ptosis and enophthalmos. Postoperative survival times ranged from 15 min to 10 weeks. Electron microscopy showed acute swelling of preganglionic cholinergic nerve terminals, followed by degeneration with separation of synapses. Other ganglionic elements appeared to be undamaged, although after detachment of synapses the dendritic postsynaptic specializations were reduced in number. Recovery was very rapid; axon growth cones were identifiable at 18 h and synapse reformation was well established by 2 weeks. With longer survival times there was progressive restoration of normal morphology such that by 8 weeks regeneration appeared complete. These experiments indicate that the preganglionic cholinergic nerve terminals are selectively affected by Latrodectus venom and have a considerable capacity for appropriate regeneration.

  7. Cystic degeneration of the tibial nerve. Magnetic resonance neurography and sonography appearances of an intraneural ganglion cyst

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    Sampaio Silveira, Claudio Regis [Sao Carlos Imaging/Sao Carlos Hospital, Musculoskeletal Imaging Division, Fortaleza, CE (Brazil); Maia Vieira, Clarissa Gadelha; Machado Pereira, Brenda [Sao Carlos Imaging/Sao Carlos Hospital, Fortaleza, CE (Brazil); Pinto Neto, Luiz Holanda [Articular Clinic, Fortaleza, CE (Brazil); Chhabra, Avneesh [UT Southwestern, Radiology and Orthopaedic Surgery, Dallas, TX (United States)

    2017-12-15

    Extra- and intraneural ganglion cysts have been described in the literature. The tibial nerve ganglion is uncommon and its occurrence without intra-articular extension is atypical. The pathogenesis of cystic degeneration localized to connective and perineural tissue secondary to chronic mechanical irritation or idiopathic mucoid degeneration is hypothesized. Since the above pathology is extremely rare and the magnetic resonance imaging examination detects the defining characteristics of the intrinsic alterations of the tibial nerve, the authors illustrate such a case of tibial intaneural ganglion cyst with its magnetic resonance neurography and sonography appearances. (orig.)

  8. Effect of eye NGF administration on two animal models of retinal ganglion cells degeneration

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    Valeria Colafrancesco

    2011-01-01

    Full Text Available The aim of this study was to investigate the effect of nerve growth factor (NGF administration on retinal ganglion cells (RGCs in experimentally induced glaucoma (GL and diabetic retinopathy (DR. GL was induced in adult rats by injection of hypertonic saline into the episcleral vein of the eye and diabetes (DT was induced by administration of streptozoticin. Control and experimental rats were treated daily with either ocular application of NGF or vehicle solution. We found that both animal models present a progressive degeneration of RGCs and changing NGF and VEGF levels in the retina and optic nerve. We then proved that NGF eye drop administration exerts a protective effect on these models of retinal degeneration. In brief, our findings indicate that NGF can play a protective role against RGC degeneration occurring in GL and DR and suggest that ocular NGF administration might be an effective pharmacological approach.

  9. Rescuing axons from degeneration does not affect retinal ganglion cell death

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    S. de Lima

    2016-01-01

    Full Text Available After a traumatic injury to the central nervous system, the distal stumps of axons undergo Wallerian degeneration (WD, an event that comprises cytoskeleton and myelin breakdown, astrocytic gliosis, and overexpression of proteins that inhibit axonal regrowth. By contrast, injured neuronal cell bodies show features characteristic of attempts to initiate the regenerative process of elongating their axons. The main molecular event that leads to WD is an increase in the intracellular calcium concentration, which activates calpains, calcium-dependent proteases that degrade cytoskeleton proteins. The aim of our study was to investigate whether preventing axonal degeneration would impact the survival of retinal ganglion cells (RGCs after crushing the optic nerve. We observed that male Wistar rats (weighing 200-400 g; n=18 treated with an exogenous calpain inhibitor (20 mM administered via direct application of the inhibitor embedded within the copolymer resin Evlax immediately following optic nerve crush showed a delay in the onset of WD. This delayed onset was characterized by a decrease in the number of degenerated fibers (P<0.05 and an increase in the number of preserved fibers (P<0.05 4 days after injury. Additionally, most preserved fibers showed a normal G-ratio. These results indicated that calpain inhibition prevented the degeneration of optic nerve fibers, rescuing axons from the process of axonal degeneration. However, analysis of retinal ganglion cell survival demonstrated no difference between the calpain inhibitor- and vehicle-treated groups, suggesting that although the calpain inhibitor prevented axonal degeneration, it had no effect on RGC survival after optic nerve damage.

  10. Intercondylar Ganglion Cyst with Mucoid Degeneration of Posterior Cruciate Ligament of Knee: Report of A Rare Case and Review of Literature

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    Vandana V Ahluwalia

    2014-01-01

    Full Text Available Introduction: Mucoid degeneration and Ganglion cysts arising from the posterior cruciate ligament (PCL of the knee are rare. The aetiology, clinical features and Magnetic resonance imaging (MRI appearance of PCL mucoid degeneration and intercondylar ganglion cyst are discussed. Case Report: We present a 36 year-old male patient who presented with chronic right knee pain for the duration of 5-6 months. No evidence of ligament instability on clinical examination was found. A diagnosis of PCL mucoid degeneration and intercondylar ganglion cyst was made on MRI. Conclusion: Mucoid degeneration and ganglion cyst involving PCL are uncommon lesions and represents the spectrum of same pathology. MR imaging is sensitive, specific, accurate and noninvasive, while providing multiplanar imaging and superior identification of the anatomical and morphological relationship of the synovial tissue to the surrounding structures, an additional intra-articular lesions can also be detected. Keywords: Ganglion cyst, mucoid degeneration, intercondylar, posterior cruciate ligament.

  11. Elevated intracranial pressure causes optic nerve and retinal ganglion cell degeneration in mice.

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    Nusbaum, Derek M; Wu, Samuel M; Frankfort, Benjamin J

    2015-07-01

    The purpose of this study was to develop a novel experimental system for the modulation and measurement of intracranial pressure (ICP), and to use this system to assess the impact of elevated ICP on the optic nerve and retinal ganglion cells (RGCs) in CD1 mice. This system involved surgical implantation of an infusion cannula and a radiowave based pressure monitoring probe through the skull and into the subarachnoid space. The infusion cannula was used to increase ICP, which was measured by the probe and transmitted to a nearby receiver. The system provided robust and consistent ICP waveforms, was well tolerated, and was stable over time. ICP was elevated to approximately 30 mmHg for one week, after which we assessed changes in optic nerve structure with transmission electron microscopy in cross section and RGC numbers with antibody staining in retinal flat mounts. ICP elevation resulted in optic nerve axonal loss and disorganization, as well as RGC soma loss. We conclude that the controlled manipulation of ICP in active, awake mice is possible, despite their small size. Furthermore, ICP elevation results in visual system phenotypes of optic nerve and RGC degeneration, suggesting that this model can be used to study the impact of ICP on the visual system. Potentially, this model can also be used to study the relationship between ICP and IOP, as well diseases impacted by ICP variation such as glaucoma, idiopathic intracranial hypertension, and the spaceflight-related visual impairment intracranial pressure syndrome. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Molecular mechanisms of retinal ganglion cell degeneration in glaucoma and future prospects for cell body and axonal protection

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    Yasunari eMunemasa

    2013-01-01

    Full Text Available Glaucoma, which affects more than 70 million people worldwide, is a heterogeneous group of disorders with a resultant common denominator; optic neuropathy, eventually leading to irreversible blindness. The clinical manifestations of primary open-angle glaucoma (POAG, the most common subtype of glaucoma, include excavation of the optic disc and progressive loss of visual field. Axonal degeneration of retinal ganglion cells (RGCs and apoptotic death of their cell bodies are observed in glaucoma, in which the reduction of intraocular pressure is known to slow progression of the disease. A pattern of localized retinal nerve fiber layer defects in glaucoma patients indicates that axonal degeneration may precede RGC body death in this condition. The mechanisms of degeneration of neuronal cell bodies and their axons may differ. In this review, we addressed the molecular mechanisms of cell body death and axonal degeneration in glaucoma and proposed axonal protection in addition to cell body protection. The concept of axonal protection may become a new therapeutic strategy to prevent further axonal degeneration or revive dying axons in patients with preperimetric glaucoma. Further study will be needed to clarify whether the combination therapy of axonal protection and cell body protection will have greater protective effects in early or progressive glaucomatous optic neuropathy.

  13. The dark phase intraocular pressure elevation and retinal ganglion cell degeneration in a rat model of experimental glaucoma☆

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    Kwong, Jacky M.K.; Vo, Nancy; Quan, Ann; Nam, Michael; Kyung, Haksu; Yu, Fei; Piri, Natik; Caprioli, Joseph

    2013-01-01

    Intraocular pressure (IOP) elevation is considered as a major risk factor causing the progression of vision deterioration in glaucoma. Although it is known that the IOP level changes widely throughout the day and night, how the dark or light phase IOP elevation contributes to retinal ganglion cell (RGC) degeneration is still largely unclear. To examine the profile of IOP, modified laser photocoagulation was applied to the trabecular meshwork of Brown Norway rats and both light and dark phase IOPs were monitored approximately 1–2 times a week. The relationship between IOP elevation and RGC degeneration was investigated while RGC body loss was analyzed with Rbpms immunolabeling on retinal wholemount and axonal injury in the optic nerve was semi-quantified. The baseline awake dark and light IOPs were 30.4 ± 2.7 and 20.2 ± 2.1 mmHg respectively. The average dark IOP was increased to 38.2 ± 3.2 mmHg for five weeks after the laser treatment on 270° trabecular meshwork. However, there was no significant loss of RGC body and axonal injury. After laser treatment on 330° trabecular meshwork, the dark and light IOPs were significantly increased to 43.8 ± 4.6 and 23 ± 3.7 mmHg respectively for 5 weeks. The cumulative dark and light IOP elevations were 277 ± 86 and 113 ± 50 mmHg days respectively while the cumulative total (light and dark) IOP elevation was 213 ± 114 mmHg days. After 5 weeks, regional RGC body loss of 29.5 ± 15.5% and moderate axonal injury were observed. Axonal injury and loss of RGC body had a high correlation with the cumulative total IOP elevation (R2 = 0.60 and 0.65 respectively). There was an association between the cumulative dark IOP elevation and RGC body loss (R2 = 0.37) and axonal injury (R2 = 0.51) whereas the associations between neuronal damages and the cumulative light IOP elevation were weak (for RGC body loss, R2 = 0.01; for axonal injury, R2 = 0.26). Simple linear regression model analysis showed statistical significance for the

  14. Regional differences in myelination of chick vestibulocochlear ganglion cells.

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    Sun, Ying-Jie; Kobayashi, Hiroto; Yoshida, Saori; Shirasawa, Nobuyuki; Naito, Akira

    2013-11-01

    In vertebrates, vestibular and cochlear ganglion (VG and CG, respectively) cells are bipolar neurons with myelinated axons and perikarya. The time course of the myelination of the VG and CG cells during development of chick embryos was investigated. Chick VG and CG from embryonic day at 7-20 (E7-20) were prepared for a transmission electron microscopy, myelin basic protein immunohistochemistry, and real-time quantitative RT-PCR. In the VG cells, myelination was first observed on the peripheral axons of the ampullar nerves at E10, on the utricular and saccular nerves at E12, and on the lagenar and neglecta nerves at E13. In the VG central axons, myelination was first seen on the ampullar nerves at E11, on the utricular and saccular nerves at E13, and on the lagenar nerves at E13. In the CG cells, the myelination was first observed on the peripheral and central axons at E14. In both VG and CG, myelination was observed on the perikarya at E17. These results suggest that the onset of the axonal myelination on the VG cells occurred earlier than that on the CG cells, whereas the perikaryal myelination occurred at about the same time on the both types of ganglion cells. Moreover, the myelination on the ampullar nerves occurred earlier than that on the utricular and saccular nerves. The myelination on the peripheral axons occurred earlier than that on the central axons of the VG cells, whereas that on the central and peripheral axons of the CG cells occurred at about the same time. The regional differences in myelination in relation to the onset of functional activities in the VG and CG cells are discussed. Copyright © 2013 ISDN. Published by Elsevier Ltd. All rights reserved.

  15. Patterns of Retinal Ganglion Cell Damage in Neurodegenerative Disorders: Parvocellular vs Magnocellular Degeneration in Optical Coherence Tomography Studies

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    Chiara La Morgia

    2017-12-01

    Full Text Available Many neurodegenerative disorders, such as Parkinson’s disease (PD and Alzheimer’s disease (AD, are characterized by loss of retinal ganglion cells (RGCs as part of the neurodegenerative process. Optical coherence tomography (OCT studies demonstrated variable degree of optic atrophy in these diseases. However, the pattern of degenerative changes affecting the optic nerve (ON can be different. In particular, neurodegeneration is more evident for magnocellular RGCs in AD and multiple system atrophy with a pattern resembling glaucoma. Conversely, in PD and Huntington’s disease, the parvocellular RGCs are more vulnerable. This latter pattern closely resembles that of mitochondrial optic neuropathies, possibly pointing to similar pathogenic mechanisms. In this review, the currently available evidences on OCT findings in these neurodegenerative disorders are summarized with particular emphasis on the different pattern of RGC loss. The ON degeneration could become a validated biomarker of the disease, which may turn useful to follow natural history and possibly assess therapeutic efficacy.

  16. APP upregulation contributes to retinal ganglion cell degeneration via JNK3.

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    Liu, Chao; Zhang, Cheng-Wu; Zhou, Yi; Wong, Wan Qing; Lee, Liying Corinne; Ong, Wei Yi; Yoon, Sung Ok; Hong, Wanjin; Fu, Xin-Yuan; Soong, Tuck Wah; Koo, Edward H; Stanton, Lawrence W; Lim, Kah-Leong; Xiao, Zhi-Cheng; Dawe, Gavin S

    2018-03-01

    Axonal injury is a common feature of central nervous system insults. Upregulation of amyloid precursor protein (APP) is observed following central nervous system neurotrauma and is regarded as a marker of central nervous system axonal injury. However, the underlying mechanism by which APP mediates neuronal death remains to be elucidated. Here, we used mouse optic nerve axotomy (ONA) to model central nervous system axonal injury replicating aspects of retinal ganglion cell (RGC) death in optic neuropathies. APP and APP intracellular domain (AICD) were upregulated in retina after ONA and APP knockout reduced Tuj1 + RGC loss. Pathway analysis of microarray data combined with chromatin immunoprecipitation and a luciferase reporter assay demonstrated that AICD interacts with the JNK3 gene locus and regulates JNK3 expression. Moreover, JNK3 was found to be upregulated after ONA and to contribute to Tuj1 + RGC death. APP knockout reduced the ONA-induced enhanced expression of JNK3 and phosphorylated JNK (pJNK). Gamma-secretase inhibitors prevented production of AICD, reduced JNK3 and pJNK expression similarly, and protected Tuj1 + RGCs from ONA-induced cell death. Together these data indicate that ONA induces APP expression and that gamma-secretase cleavage of APP releases AICD, which upregulates JNK3 leading to RGC death. This pathway may be a novel target for neuronal protection in optic neuropathies and other forms of neurotrauma.

  17. Network oscillations drive correlated spiking of ON and OFF ganglion cells in the rd1 mouse model of retinal degeneration.

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    David J Margolis

    Full Text Available Following photoreceptor degeneration, ON and OFF retinal ganglion cells (RGCs in the rd-1/rd-1 mouse receive rhythmic synaptic input that elicits bursts of action potentials at ∼ 10 Hz. To characterize the properties of this activity, RGCs were targeted for paired recording and morphological classification as either ON alpha, OFF alpha or non-alpha RGCs using two-photon imaging. Identified cell types exhibited rhythmic spike activity. Cross-correlation of spike trains recorded simultaneously from pairs of RGCs revealed that activity was correlated more strongly between alpha RGCs than between alpha and non-alpha cell pairs. Bursts of action potentials in alpha RGC pairs of the same type, i.e. two ON or two OFF cells, were in phase, while bursts in dissimilar alpha cell types, i.e. an ON and an OFF RGC, were 180 degrees out of phase. This result is consistent with RGC activity being driven by an input that provides correlated excitation to ON cells and inhibition to OFF cells. A2 amacrine cells were investigated as a candidate cellular mechanism and found to display 10 Hz oscillations in membrane voltage and current that persisted in the presence of antagonists of fast synaptic transmission and were eliminated by tetrodotoxin. Results support the conclusion that the rhythmic RGC activity originates in a presynaptic network of electrically coupled cells including A2s via a Na(+-channel dependent mechanism. Network activity drives out of phase oscillations in ON and OFF cone bipolar cells, entraining similar frequency fluctuations in RGC spike activity over an area of retina that migrates with changes in the spatial locus of the cellular oscillator.

  18. Network oscillations drive correlated spiking of ON and OFF ganglion cells in the rd1 mouse model of retinal degeneration.

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    Margolis, David J; Gartland, Andrew J; Singer, Joshua H; Detwiler, Peter B

    2014-01-01

    Following photoreceptor degeneration, ON and OFF retinal ganglion cells (RGCs) in the rd-1/rd-1 mouse receive rhythmic synaptic input that elicits bursts of action potentials at ∼ 10 Hz. To characterize the properties of this activity, RGCs were targeted for paired recording and morphological classification as either ON alpha, OFF alpha or non-alpha RGCs using two-photon imaging. Identified cell types exhibited rhythmic spike activity. Cross-correlation of spike trains recorded simultaneously from pairs of RGCs revealed that activity was correlated more strongly between alpha RGCs than between alpha and non-alpha cell pairs. Bursts of action potentials in alpha RGC pairs of the same type, i.e. two ON or two OFF cells, were in phase, while bursts in dissimilar alpha cell types, i.e. an ON and an OFF RGC, were 180 degrees out of phase. This result is consistent with RGC activity being driven by an input that provides correlated excitation to ON cells and inhibition to OFF cells. A2 amacrine cells were investigated as a candidate cellular mechanism and found to display 10 Hz oscillations in membrane voltage and current that persisted in the presence of antagonists of fast synaptic transmission and were eliminated by tetrodotoxin. Results support the conclusion that the rhythmic RGC activity originates in a presynaptic network of electrically coupled cells including A2s via a Na(+)-channel dependent mechanism. Network activity drives out of phase oscillations in ON and OFF cone bipolar cells, entraining similar frequency fluctuations in RGC spike activity over an area of retina that migrates with changes in the spatial locus of the cellular oscillator.

  19. Macular ganglion cell complex and retinal nerve fiber layer comparison in different stages of age-related macular degeneration.

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    Zucchiatti, Ilaria; Parodi, Maurizio Battaglia; Pierro, Luisa; Cicinelli, Maria Vittoria; Gagliardi, Marco; Castellino, Niccolò; Bandello, Francesco

    2015-09-01

    To employ optical coherence tomography (OCT) to analyze the morphologic changes in the inner retina in different categories of age-related macular degeneration (AMD). Observational cross-sectional study. Single-center study. Inclusion criteria were age over 50, diagnosis of Age-Related Eye Disease Study (AREDS) category 2 and 3, naïve neovascular AMD, and atrophic AMD. Healthy patients of similar age acted as a control group. Primary outcome measures were the changes in ganglion cell complex (GCC) and retinal nerve fiber layer (RNFL). Secondary outcomes included modifications of rim area and cup-to-disc ratio. One hundred and thirty eyes of 130 patients were recruited: 26 eyes for AREDS category 2, 26 for AREDS category 3, 26 for neovascular AMD, 26 with atrophic AMD, and 26 controls. Mean peripapillary RNFL thickness was significantly lower in neovascular AMD, compared to controls (P = .004); peripapillary RNFL did not significantly vary among AREDS category 2 and 3 and atrophic AMD groups, compared to controls. Mean GCC thickness was higher in the control group, becoming progressively thinner up to neovascular and atrophic AMD groups (P < .0001). Rim area was significantly thinner in the neovascular AMD group compared with controls (P = .047); cup-to-disc ratio was higher in the neovascular AMD group compared with the control group (P = .047). This study demonstrates that eyes with neovascular AMD display reduced RNFL and GCC thickness. RNFL is partially spared in atrophic advanced AMD. The identification of alteration in RNFL and GCC thickness may reveal useful for future therapeutic implications. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. EFFECT OF INTRAVITREAL RANIBIZUMAB ON GANGLION CELL COMPLEX AND PERIPAPILLARY RETINAL NERVE FIBER LAYER IN NEOVASCULAR AGE-RELATED MACULAR DEGENERATION USING SPECTRAL DOMAIN OPTICAL COHERENCE TOMOGRAPHY.

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    Zucchiatti, Ilaria; Cicinelli, Maria V; Parodi, Maurizio Battaglia; Pierro, Luisa; Gagliardi, Marco; Accardo, Agostino; Bandello, Francesco

    2017-07-01

    To analyze the changes in ganglion cell complex and peripapillary retinal nerve fiber layer thickness, in central macular thickness and choroidal thickness on spectral domain optical coherence tomography in patients with neovascular age-related macular degeneration treated with intravitreal ranibizumab injections. All consecutive patients with untreated neovascular age-related macular degeneration received loading phase of three monthly intravitreal ranibizumab, followed by retreatments on a pro re nata protocol for 12 months. changes in ganglion cell complex and retinal nerve fiber layer at the end of follow-up. Secondary outcome: changes in best-corrected visual acuity, central macular thickness, and choroidal thickness at the end of follow-up. Choroidal thickness was measured at 500 μm, 1000 μm, and 1,500 μm intervals nasally, temporally, superiorly, and inferiorly to the fovea, respectively, on horizontal and vertical line scans centered on the fovea. Twenty-four eyes were included. Ganglion cell complex and peripapillary retinal nerve fiber layer thickness did not show statistically significant changes through 12 months (55.6 ± 18.5 and 81.9 ± 9.9 μm at baseline, 52.7 ± 19.3 and 84.6 ± 15.5 μm at month 12, P > 0.05). Central macular thickness showed progressive decrease from baseline to month 12, with maximum reduction at month 3 (P retinal nerve fiber layer and ganglion cell complex thickness in 1-year follow-up. Choroidal thickness in papillomacular area and central macular thickness was significantly reduced at the end of treatment. Further studies, with larger sample, longer follow-up, and greater number of injections, are warranted.

  1. Time-Dependent Nerve Growth Factor Signaling Changes in the Rat Retina During Optic Nerve Crush-Induced Degeneration of Retinal Ganglion Cells.

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    Mesentier-Louro, Louise A; De Nicolò, Sara; Rosso, Pamela; De Vitis, Luigi A; Castoldi, Valerio; Leocani, Letizia; Mendez-Otero, Rosalia; Santiago, Marcelo F; Tirassa, Paola; Rama, Paolo; Lambiase, Alessandro

    2017-01-05

    Nerve growth factor (NGF) is suggested to be neuroprotective after nerve injury; however, retinal ganglion cells (RGC) degenerate following optic-nerve crush (ONC), even in the presence of increased levels of endogenous NGF. To further investigate this apparently paradoxical condition, a time-course study was performed to evaluate the effects of unilateral ONC on NGF expression and signaling in the adult retina. Visually evoked potential and immunofluorescence staining were used to assess axonal damage and RGC loss. The levels of NGF, proNGF, p75 NTR , TrkA and GFAP and the activation of several intracellular pathways were analyzed at 1, 3, 7 and 14 days after crush (dac) by ELISA/Western Blot and PathScan intracellular signaling array. The progressive RGC loss and nerve impairment featured an early and sustained activation of apoptotic pathways; and GFAP and p75 NTR enhancement. In contrast, ONC-induced reduction of TrkA, and increased proNGF were observed only at 7 and 14 dac. We propose that proNGF and p75 NTR contribute to exacerbate retinal degeneration by further stimulating apoptosis during the second week after injury, and thus hamper the neuroprotective effect of the endogenous NGF. These findings might aid in identifying effective treatment windows for NGF-based strategies to counteract retinal and/or optic-nerve degeneration.

  2. Time-Dependent Nerve Growth Factor Signaling Changes in the Rat Retina During Optic Nerve Crush-Induced Degeneration of Retinal Ganglion Cells

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    Louise A. Mesentier-Louro

    2017-01-01

    Full Text Available Nerve growth factor (NGF is suggested to be neuroprotective after nerve injury; however, retinal ganglion cells (RGC degenerate following optic-nerve crush (ONC, even in the presence of increased levels of endogenous NGF. To further investigate this apparently paradoxical condition, a time-course study was performed to evaluate the effects of unilateral ONC on NGF expression and signaling in the adult retina. Visually evoked potential and immunofluorescence staining were used to assess axonal damage and RGC loss. The levels of NGF, proNGF, p75NTR, TrkA and GFAP and the activation of several intracellular pathways were analyzed at 1, 3, 7 and 14 days after crush (dac by ELISA/Western Blot and PathScan intracellular signaling array. The progressive RGC loss and nerve impairment featured an early and sustained activation of apoptotic pathways; and GFAP and p75NTR enhancement. In contrast, ONC-induced reduction of TrkA, and increased proNGF were observed only at 7 and 14 dac. We propose that proNGF and p75NTR contribute to exacerbate retinal degeneration by further stimulating apoptosis during the second week after injury, and thus hamper the neuroprotective effect of the endogenous NGF. These findings might aid in identifying effective treatment windows for NGF-based strategies to counteract retinal and/or optic-nerve degeneration.

  3. Fatty Acids Dietary Supplements Exert Anti-Inflammatory Action and Limit Ganglion Cell Degeneration in the Retina of the EAE Mouse Model of Multiple Sclerosis

    Directory of Open Access Journals (Sweden)

    Massimo Dal Monte

    2018-03-01

    Full Text Available Optic neuritis is an acute inflammatory demyelinating disorder of the optic nerve (ON and is an initial symptom of multiple sclerosis (MS. Optic neuritis is characterized by ON degeneration and retinal ganglion cell (RGC loss that contributes to permanent visual disability and lacks a reliable treatment. Here, we used the experimental autoimmune encephalomyelitis (EAE mouse model of MS, a well-established model also for optic neuritis. In this model, C57BL6 mice, intraperitoneally injected with a fragment of the myelin oligodendrocyte glycoprotein (MOG, were found to develop inflammation, Müller cell gliosis, and infiltration of macrophages with increased production of oncomodulin (OCM, a calcium binding protein that acts as an atypical trophic factor for neurons enabling RGC axon regeneration. Immunolabeling of retinal whole mounts with a Brn3a antibody demonstrated drastic RGC loss. Dietary supplementation with Neuro-FAG (nFAG®, a balanced mixture of fatty acids (FAs, counteracted inflammatory and gliotic processes in the retina. In contrast, infiltration of macrophages and their production of OCM remained at elevated levels thus eventually preserving OCM trophic activity. In addition, the diet supplement with nFAG exerted a neuroprotective effect preventing MOG-induced RGC death. In conclusion, these data suggest that the balanced mixture of FAs may represent a useful form of diet supplementation to limit inflammatory events and death of RGCs associated to optic neuritis. This would occur without affecting macrophage infiltration and the release of OCM thus favoring the maintenance of OCM neuroprotective role.

  4. Exploring the nearly degenerate stop region with sbottom decays

    Energy Technology Data Exchange (ETDEWEB)

    An, Haipeng [California Institute of Technology, Pasadena, CA (United States). Walter Burke Inst. for Theoretical Physics; Gu, Jiayin [Chinese Academy of Sciences, Beijing (China). Inst. of High Energy Physics; Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Wang, Lian-Tao [Chicago Univ., IL (United States). Enrico Fermi Inst.; Chicago Univ., IL (United States). Kavli Inst. for Cosmological Physics

    2016-11-15

    A light stop with mass almost degenerate with the lightest neutralino has important connections with both naturalness and dark matter relic abundance. This region is also very hard to probe at colliders. In this paper, we demonstrate the potential of searching for such stop particles at the LHC from sbottom decays, focusing on two channels with final states 2l+E{sup miss}{sub T} and 1b1l+E{sup miss}{sub T}. We found that, if the lightest sbottom has mass around or below 1 TeV and has a significant branching ratio to decay to stop and W (b→tW), a stop almost degenerate with neutralino can be excluded up to about 500-600 GeV at the 13 TeV LHC with 300 fb{sup -1} data. The searches we propose are complementary to other SUSY searches at the LHC and could have the best sensitivity to the stop-bino coannihilation region. Since they involve final states which have already been used in LHC searches, a reinterpretation of the search results already has sensitivity. Further optimization could deliver the full potential of these channels.

  5. Exploring the nearly degenerate stop region with sbottom decays

    Energy Technology Data Exchange (ETDEWEB)

    An, Haipeng [Walter Burke Institute for Theoretical Physics, California Institute of Technology,1200 E. California Blvd, Pasadena, CA, 91125 (United States); Gu, Jiayin [Center for Future High Energy Physics, Institute of High Energy Physics,19B YuquanLu, Chinese Academy of Sciences, Beijing, 100049 (China); DESY,Notkestraße 85, Hamburg, D-22607 (Germany); Wang, Lian-Tao [Enrico Fermi Institute, University of Chicago,5640 S Ellis Ave., Chicago, IL, 60637 (United States); Kavli Institute for Cosmological Physics, University of Chicago,5640 S Ellis Ave., Chicago, IL, 60637 (United States)

    2017-04-13

    A light stop with mass almost degenerate with the lightest neutralino has important connections with both naturalness and dark matter relic abundance. This region is also very hard to probe at colliders. In this paper, we demonstrate the potential of searching for such stop particles at the LHC from sbottom decays, focusing on two channels with final states 2ℓ+E{sub T}{sup miss} and 1b1ℓ+E{sub T}{sup miss}. We found that, if the lightest sbottom has mass around or below 1 TeV and has a significant branching ratio to decay to stop and W (b̃→t̃ W), a stop almost degenerate with neutralino can be excluded up to about 500–600 GeV at the 13 TeV LHC with 300 fb{sup −1} data. The searches we propose are complementary to other SUSY searches at the LHC and could have the best sensitivity to the stop-bino coannihilation region. Since they involve final states which have already been used in LHC searches, a reinterpretation of the search results already has sensitivity. Further optimization could deliver the full potential of these channels.

  6. Expanding the spectrum of human ganglionic eminence region anomalies on fetal magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Righini, Andrea; Parazzini, Cecilia; Izzo, Giana [Children' s Hospital ' ' V. Buzzi' ' , Department of Radiology and Neuroradiology, Milan (Italy); Cesaretti, Claudia [Children' s Hospital ' ' V. Buzzi' ' , Department of Radiology and Neuroradiology, Milan (Italy); Ospedale Maggiore Policlinico, Medical Genetics Unit, Fondazione I.R.C.C.S. Ca' Granda, Milan (Italy); Conte, Giorgio [Children' s Hospital ' ' V. Buzzi' ' , Department of Radiology and Neuroradiology, Milan (Italy); University of Milan, Department of Health Sciences, Milan (Italy); Frassoni, Carolina; Inverardi, Francesca [Fondazione I.R.C.C.S. Istituto Neurologico ' ' C. Besta' ' , Clinical Epileptology and Experimental Neurophysiology Unit, Milan (Italy); Bulfamante, Gaetano; Avagliano, Laura [San Paolo Hospital, Division of Human Pathology, Milan (Italy); Rustico, Mariangela [Children' s Hospital ' ' V. Buzzi' ' , Department of Obstetrics and Gynaecology, Prenatal Diagnosis, Milan (Italy)

    2016-03-15

    Ganglionic eminence (GE) is a transient fetal brain structure that harvests a significant amount of precursors of cortical GABA-ergic interneurons. Prenatal magnetic resonance (MR) imaging features of GE anomalies (i.e., cavitations) have already been reported associated with severe micro-lissencephaly. The purpose of this report was to illustrate the MR imaging features of GE anomalies in conditions other than severe micro-lissencephalies. Among all the fetuses submitted to prenatal MR imaging at our center from 2005 to 2014, we collected eight cases with GE anomalies and only limited associated brain anomalies. The median gestational age at the time of MR imaging was 21 weeks ranging from 19 to 29 weeks. Two senior pediatric neuroradiologists categorized the anomalies of the GE region in two groups: group one showing cavitation in the GE region and group two showing enlarged GE region. For each fetal case, associated cranial anomalies were also reported. Five out of the eight cases were included in group one and three in group two. Besides the GE region abnormality, all eight cases had additional intracranial anomalies, such as mild partial callosal agenesis, vermian hypoplasia and rotation, cerebellar hypoplasia, ventriculomegaly, enlarged subarachnoid spaces, molar tooth malformation. Ultrasound generally detected most of the associated intracranial anomalies, prompting the MR investigation; on the contrary in none of the cases, GE anomalies had been detected by ultrasound. Our observation expands the spectrum of human GE anomalies, demonstrating that these may take place also without associated severe micro-lissencephalies. (orig.)

  7. The meniscus ganglion

    International Nuclear Information System (INIS)

    Schaefer, H.

    1982-01-01

    Normal dimensions of the meniscus quoted in the literature vary somewhat; measurements were therefore carried out on the height and width on standardised arthrograms. This made it possible to evaluate changes in the height of the meniscus objectively and to diagnose degeneration with a ganglion at an earlier stage. Taking into account other, secondary, signs, 261 meniscus ganglia were diagnosed amongst 3133 meniscus lesions (8.3%) in the course of 5650 knee arthrograms. These were confirmed at operation and histologically. For the first time it has been possible to provide an estimate of the frequency of meniscus ganglion in the radiological literature. (orig.) [de

  8. Ganglion Cysts

    Science.gov (United States)

    ... cyst Figure 3 - Cross-section of wrist showing the root of a ganglion cyst PDF Ganglion Cysts Related Conditions Trigger Finger Hand Tumors and Wrist Tumors de Quervain's Tenosynovitis Carpometacarpal Boss Other Links CME Mission Statement and ...

  9. Regional cerebral glucose metabolism in frontotemporal lobar degeneration

    International Nuclear Information System (INIS)

    Park, J.M.; Cho, S.S.; Lee, K.-H.; Choi, Y.; Choe, Y.S.; Kim, B.-T.; Kim, S.E.; Kwon, J.C.; Na, D.L.

    2002-01-01

    Purpose: Frontotemporal lobar degeneration (FTLD) is the third most common cause of dementia, following Alzheimer's disease and Lewy body disease. Four prototypic neuro behavioral syndromes can be produced by FTLD: frontotemporal dementia (FTD), frontotemporal dementia with motor neuron disease (MND), semantic dementia (SD), and progressive aphasia (PA). We investigated patterns of metabolic impairment in patients with FTLD presented with four different clinical syndromes. Methods: We analyzed glucose metabolic patterns on FDG PET images obtained from 34 patients with a clinical diagnosis of FTLD (19 FTD, 6 MND, 6 SD, and 3 PA, according to a consensus criteria for clinical syndromes associated with FTLD) and 7 age-matched healthy controls using SPM99. Results: Patients with FTD had metabolic deficit in the left frontal cortex and bilateral anterior temporal cortex. Hypometabolism in the bilateral pre-motor area was shown in patients with MND. Patients with SD had metabolic deficit in the left posterior temporal cortex including Wernicke's area, while hypometabolism in the bilateral inferior frontal gyrus including Broca's area and left angular gyrus was seen in patients with PA. These metabolic patterns were well correlated with clinical and neuropsychological features of FTLD syndromes. Conclusion: These data provide a biochemical basis of clinical classification of FTLD. FDG PET may help evaluate and classify patients with FTLD

  10. THICKNESS OF THE MACULA, RETINAL NERVE FIBER LAYER, AND GANGLION CELL-INNER PLEXIFORM LAYER IN THE AGE-RELATED MACULAR DEGENERATION: The Repeatability Study of Spectral Domain Optical Coherence Tomography.

    Science.gov (United States)

    Shin, Il-Hwan; Lee, Woo-Hyuk; Lee, Jong-Joo; Jo, Young-Joon; Kim, Jung-Yeul

    2018-02-01

    To determine the repeatability of measuring the thickness of the central macula, retinal nerve fiber layer, and ganglion cell-inner plexiform layer (GC-IPL) using spectral domain optical coherence tomography (Cirrus HD-OCT) in eyes with age-related macular degeneration. One hundred and thirty-four eyes were included. The measurement repeatability was assessed by an experienced examiner who performed two consecutive measurements using a 512 × 128 macular cube scan and a 200 × 200 optic disk cube scan. To assess changes in macular morphology in patients with age-related macular degeneration, the patients were divided into the following three groups according to the central macular thickness (CMT): A group, CMT 300 μm. Measurement repeatability was assessed using test-retest variability, a coefficient of variation, and an intraclass correlation coefficient. The mean measurement repeatability for the central macular, retinal nerve fiber layer, and GC-IPL thickness was high in the B group. The mean measurement repeatability for both the central macula and retinal nerve fiber layer thickness was high in the A and C groups, but was lower for the GC-IPL thickness. The measurement repeatability for GC-IPL thickness was high in the B group, but low in the A group and in the C group. The automated measurement repeatability for GC-IPL thickness was significantly lower in patients with age-related macular degeneration with out of normal CMT range. The effect of changes in macular morphology should be considered when analyzing GC-IPL thicknesses in a variety of ocular diseases.

  11. Intravenous regional block is similar to sympathetic ganglion block for pain management in patients with complex regional pain syndrome type I

    Directory of Open Access Journals (Sweden)

    M.S.A. Nascimento

    2010-12-01

    Full Text Available Sympathetic ganglion block (SGB or intravenous regional block (IVRB has been recommended for pain management in patients with complex regional pain syndrome type I (CRPS-I. Forty-five patients were initially selected but only 43 were accepted for the study. The present study evaluated the efficacy of IVRB produced by combining 70 mg lidocaine with 30 µg clonidine (14 patients, 1 male/13 females, age range: 27-50 years versus SGB produced by the injection of 70 mg lidocaine alone (14 patients, 1 male/13 females, age range: 27-54 years or combined with 30 µg clonidine (15 patients, 1 male/14 females, age range: 25-50 years into the stellate ganglion for pain management in patients with upper extremity CRPS-I. Each procedure was repeated five times at 7-day intervals, and pain intensity and duration were measured using a visual analog scale immediately before each procedure. A progressive and significant reduction in pain scores and a significant increase in the duration of analgesia were observed in all groups following the first three blocks, but no further improvement was obtained following the last two blocks. Drowsiness, the most frequent side effect, and dry mouth occurred only in patients submitted to SGB with lidocaine combined with clonidine. The three methods were similar regarding changes in pain intensity and duration of analgesia. However, IVRB seems to be preferable to SGB due to its easier execution and lower risk of undesirable effects.

  12. Selective Fiber Degeneration in the Peripheral Nerve of a Patient With Severe Complex Regional Pain Syndrome

    Directory of Open Access Journals (Sweden)

    Adrien Yvon

    2018-04-01

    Full Text Available Aims: Complex regional pain syndrome (CRPS is characterized by chronic debilitating pain disproportional to the inciting event and accompanied by motor, sensory, and autonomic disturbances. The pathophysiology of CRPS remains elusive. An exceptional case of severe CRPS leading to forearm amputation provided the opportunity to examine nerve histopathological features of the peripheral nerves.Methods: A 35-year-old female developed CRPS secondary to low voltage electrical injury. The CRPS was refractory to medical therapy and led to functional loss of the forelimb, repeated cutaneous wound infections leading to hospitalization. Specifically, the patient had exhausted a targeted conservative pain management programme prior to forearm amputation. Radial, median, and ulnar nerve specimens were obtained from the amputated limb and analyzed by light and transmission electron microscopy (TEM.Results: All samples showed features of selective myelinated nerve fiber degeneration (47–58% of fibers on electron microscopy. Degenerating myelinated fibers were significantly larger than healthy fibers (p < 0.05, and corresponded to the larger Aα fibers (motor/proprioception whilst smaller Aδ (pain/temperature fibers were spared. Groups of small unmyelinated C fibers (Remak bundles also showed evidence of degeneration in all samples.Conclusions: We are the first to show large fiber degeneration in CRPS using TEM. Degeneration of Aα fibers may lead to an imbalance in nerve signaling, inappropriately triggering the smaller healthy Aδ fibers, which transmit pain and temperature. These findings suggest peripheral nerve degeneration may play a key role in CRPS. Improved knowledge of pathogenesis will help develop more targeted treatments.

  13. Continuous Thoracic Sympathetic Ganglion Block in Complex Regional Pain Syndrome Patients with Spinal Cord Stimulation Implantation

    Directory of Open Access Journals (Sweden)

    EungDon Kim

    2016-01-01

    Full Text Available The sympathetic block is widely used for treating neuropathic pain such as complex regional pain syndrome (CRPS. However, single sympathetic block often provides only short-term effect. Moreover, frequent procedures for sympathetic block may increase the risk of complications. The use of epidural route may be limited by concern of infection in case of previous implantation of the spinal cord stimulation (SCS. In contrast, a continuous sympathetic block can be administered without such concerns. The continuous thoracic sympathetic block (TSGB has been used to treat the ischemic disease and other neuropathic conditions such as postherpetic neuralgia. We administered continuous thoracic sympathetic block using catheter in CRPS patients who underwent SCS implantations and achieved desirable outcomes. We believe a continuous sympathetic block is a considerable option before performing neurolysis or radiofrequency rhizotomy and even after SCS implantation.

  14. Sub-regional hippocampal injury is associated with fornix degeneration in Alzheimer's disease

    Directory of Open Access Journals (Sweden)

    Dong Young Lee

    2012-04-01

    Full Text Available We examined in vivo evidence of axonal degeneration in association with neuronal pathology in Alzheimer’s disease (AD through analysis of fornix microstructural integrity and measures of hippocampal subfield atrophy. Based on known anatomical topography, we hypothesized that the local thickness of subiculum and CA1 hippocampus fields would be associated with fornix integrity, reflecting an association between AD-related injury to hippocampal neurons and degeneration of associated axon fibers. To test this hypothesis, multi-modal imaging, combining measures of local hippocampal radii with diffusion tensor imaging (DTI, was applied to 44 individuals clinically diagnosed with AD, 44 individuals clinically diagnosed with mild cognitive impairment (MCI, and 96 cognitively normal individuals. Fornix microstructural degradation, as measured by reduced DTI-based fractional anisotropy (FA, was prominent in both MCI and AD, and was associated with reduced hippocampal volumes. Further, reduced fornix FA was associated with reduced anterior CA1 and antero-medial subiculum thickness. Finally, while both lesser fornix FA and lesser hippocampal volume were associated with lesser episodic memory, only the hippocampal measures were significant predictors of episodic memory in models including both hippocampal and fornix predictors. The region-specific association between fornix integrity and hippocampal neuronal death may provide in vivo evidence for degenerative white matter injury in AD: axonal pathology that is closely linked to neuronal injury.

  15. Sub-Regional Hippocampal Injury is Associated with Fornix Degeneration in Alzheimer’s Disease

    Science.gov (United States)

    Lee, Dong Young; Fletcher, Evan; Carmichael, Owen Thomas; Singh, Baljeet; Mungas, Dan; Reed, Bruce; Martinez, Oliver; Buonocore, Michael H.; Persianinova, Maria; DeCarli, Charles

    2012-01-01

    We examined in vivo evidence of axonal degeneration in association with neuronal pathology in Alzheimer’s disease (AD) through analysis of fornix microstructural integrity and measures of hippocampal subfield atrophy. Based on known anatomical topography, we hypothesized that the local thickness of subiculum and CA1 hippocampus fields would be associated with fornix integrity, reflecting an association between AD-related injury to hippocampal neurons and degeneration of associated axon fibers. To test this hypothesis, multi-modal imaging, combining measures of local hippocampal radii with diffusion tensor imaging (DTI), was applied to 44 individuals clinically diagnosed with AD, 44 individuals clinically diagnosed with mild cognitive impairment (MCI), and 96 cognitively normal individuals. Fornix microstructural degradation, as measured by reduced DTI-based fractional anisotropy (FA), was prominent in both MCI and AD, and was associated with reduced hippocampal volumes. Further, reduced fornix FA was associated with reduced anterior CA1 and antero-medial subiculum thickness. Finally, while both lesser fornix FA and lesser hippocampal volume were associated with lesser episodic memory, only the hippocampal measures were significant predictors of episodic memory in models including both hippocampal and fornix predictors. The region-specific association between fornix integrity and hippocampal neuronal death may provide in vivo evidence for degenerative white matter injury in AD: axonal pathology that is closely linked to neuronal injury. PMID:22514534

  16. Dorsal root ganglion stimulation attenuates the BOLD signal response to noxious sensory input in specific brain regions: Insights into a possible mechanism for analgesia.

    Science.gov (United States)

    Pawela, Christopher P; Kramer, Jeffery M; Hogan, Quinn H

    2017-02-15

    Targeted dorsal root ganglion (DRG) electrical stimulation (i.e. ganglionic field stimulation - GFS) is an emerging therapeutic approach to alleviate chronic pain. Here we describe blood oxygen-level dependent (BOLD) functional magnetic resonance imaging (fMRI) responses to noxious hind-limb stimulation in a rat model that replicates clinical GFS using an electrode implanted adjacent to the DRG. Acute noxious sensory stimulation in the absence of GFS caused robust BOLD fMRI response in brain regions previously associated with sensory and pain-related response, such as primary/secondary somatosensory cortex, retrosplenial granular cortex, thalamus, caudate putamen, nucleus accumbens, globus pallidus, and amygdala. These regions differentially demonstrated either positive or negative correlation to the acute noxious stimulation paradigm, in agreement with previous rat fMRI studies. Therapeutic-level GFS significantly attenuated the global BOLD response to noxious stimulation in these regions. This BOLD signal attenuation persisted for 20minutes after the GFS was discontinued. Control experiments in sham-operated animals showed that the attenuation was not due to the effect of repetitive noxious stimulation. Additional control experiments also revealed minimal BOLD fMRI response to GFS at therapeutic intensity when presented in a standard block-design paradigm. High intensity GFS produced a BOLD signal map similar to acute noxious stimulation when presented in a block-design. These findings are the first to identify the specific brain region responses to neuromodulation at the DRG level and suggest possible mechanisms for GFS-induced treatment of chronic pain. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. Uptake of Retrograde Tracers by Intact Optic Nerve Axons: A New Way to Label Retinal Ganglion Cells

    OpenAIRE

    Liang, Yu-Xiang; Yang, Jian; Yuan, Ti-Fei; So, Kwok-Fai

    2015-01-01

    Retrograde labelling of retinal ganglion cells with optic nerve transection often leads to degeneration of ganglion cells in prolonged experiments. Here we report that an intact optic nerve could uptake retrograde tracers applied onto the surface of the nerve, leading to high efficiency labelling of ganglion cells in the retina with long-term survival of cells. This method labelled a similar number of ganglion cells (2289 +/- 174 at 2 days) as the retrograde labeling technique from the superi...

  18. Spiral ganglion cell morphology in guinea pigs after deafening and neurotrophic treatment

    NARCIS (Netherlands)

    van Loon, M.C.; Ramekers, D.; Agterberg, M.J.H.; de Groot, J.C.M.J.; Grolman, W.; Klis, S.F.L.; Versnel, H.

    2013-01-01

    It is well known that spiral ganglion cells (SGCs) degenerate in hair-cell-depleted cochleas and that treatment with exogenous neurotrophins can prevent this degeneration. Several studies reported that, in addition, SGC size decreases after deafening and increases after neurotrophic treatment. The

  19. Degeneration of auditory nerve fibers in guinea pigs with severe sensorineural hearing loss

    NARCIS (Netherlands)

    Kroon, Steven; Ramekers, Dyan; Smeets, Emma M; Hendriksen, Ferry G J; Klis, Sjaak F L; Versnel, Huib

    Damage to and loss of the organ of Corti leads to secondary degeneration of the spiral ganglion cell (SGC) somata of the auditory nerve. Extensively examined in animal models, this degeneration process of SGC somata following deafening is well known. However, degeneration of auditory nerve axons,

  20. Striatonigral Degeneration

    Science.gov (United States)

    ... See More About Research The NINDS supports and conducts research on disorders of the brain and nervous system such as striatonigral degeneration. This research ... Publications Definition Striatonigral ...

  1. Retinal ganglion cell topography in elasmobranchs.

    Science.gov (United States)

    Bozzano, A; Collin, S P

    2000-04-01

    Retinal wholemounts are used to examine the topographic distribution of retinal cells within the ganglion cell layer in a range of elasmobranchs from different depths. The retina is examined for regional specializations for acute vision in six species of selachians, Galeocerdo cuvieri, Hemiscyllium ocellatum, Scyliorhinus canicula, Galeus melastomus, Etmopterus spinax, Isistius brasiliensis, one species of batoid, Raja bigelowi and one species of chimaera, Hydrolagus mirabilis. These species represent a range of lifestyles including pelagic, mesopelagic and benthic habitats, living from shallow water to the sea bottom at a depth of more than 3000 m. The topography of cells within the ganglion cell layer is non-uniform and changes markedly across the retina. Most species possess an increased density of cells across the horizontal (dorsal) meridian or visual streak, with a density range of 500 to 2,500 cells per mm(2) with one or more regional increases in density lying within this specialized horizontal area. It is proposed that the higher spatial resolving power provided by the horizontal streak in these species mediates panoramic vision in the lower frontal visual field. Only I. brasiliensis possesses a concentric arrangement of retinal iso-density contours in temporal retina or an area centralis, thereby increasing spatial resolving power in a more specialized part of the visual field, an adaptation for its unusual feeding behavior. In Nissl-stained material, amacrine and ganglion cell populations could be distinguished on the criteria of soma size, soma shape and nuclear staining. Quantitative analyses show that the proportion of amacrine cells lying within the ganglion cell layer is non-uniform and ranges between 0.4 and 12.3% in specialized retinal areas and between 8.2 and 48.1% in the peripheral non-specialized regions. Analyses of soma area of the total population of cells in the ganglion cell layer also show that the pelagic species possess significantly

  2. Thorny ganglion cells in marmoset retina: Morphological and neurochemical characterization with antibodies against calretinin.

    Science.gov (United States)

    Chandra, Ashleigh J; Lee, Sammy C S; Grünert, Ulrike

    2017-12-15

    In primates, over 17 morphological types of retinal ganglion cell have been distinguished by their dendritic morphology and stratification, but reliable markers for specific ganglion cell populations are still rare. The calcium binding protein calretinin is known to be expressed in the inner nuclear and the ganglion cell layer of marmoset retina, however, the specific cell type(s) expressing calretinin in the ganglion cell layer are yet to be determined. Here, we identified calretinin positive retinal ganglion cells in the common marmoset Callithrix jacchus. Double labeling with the ganglion cell marker RBPMS demonstrated that the large majority (80%) of the calretinin positive cells in the ganglion cell layer are ganglion cells, and 20% are displaced amacrine cells. The calretinin positive ganglion cells made up on average 12% of the total ganglion cell population outside of the foveal region and their proportion increased with eccentricity. Prelabeling with antibodies against calretinin and subsequent intracellular injection with DiI revealed that the large majority of the injected cells (n = 74) were either narrow thorny or broad thorny ganglion cells, 14 cells were displaced amacrine cells. Narrow thorny cells were further distinguished into outer and inner stratifying cells. In addition, weakly labeled cells with a large soma were identified as parasol ganglion cells. Our results show that three types of thorny ganglion cells in marmoset retina can be identified with antibodies against calretinin. Our findings are also consistent with the idea that the proportion of wide-field ganglion cell types increases in peripheral retina. © 2017 Wiley Periodicals, Inc.

  3. Hepatocerebral degeneration

    Science.gov (United States)

    Hepatocerebral degeneration is a brain disorder that occurs in people with liver damage. ... This condition may occur in any case of acquired liver failure, ... can damage brain tissue. Specific areas of the brain, such as ...

  4. Incomplete segregation of endorgan-specific vestibular ganglion cells in mice and rats

    Science.gov (United States)

    Maklad, A.; Fritzsch, B.

    1999-01-01

    The endorgan-specific distribution of vestibular ganglion cells was studied in neonatal and postnatal rats and mice using indocarbocyanine dye (DiI) and dextran amines for retrograde and anterograde labeling. Retrograde DiI tracing from the anterior vertical canal labeled neurons scattered throughout the whole superior vestibular ganglion, with denser labeling at the dorsal and central regions. Horizontal canal neurons were scattered along the dorsoventral axis with more clustering toward the dorsal and ventral poles of this axis. Utricular ganglion cells occupied predominantly the central region of the superior vestibular ganglion. This utricular population overlapped with both the anterior vertical and horizontal canals' ganglion cells. Posterior vertical canal neurons were clustered in the posterior part of the inferior vestibular ganglion. The saccular neurons were distributed in the two parts of the vestibular ganglion, the superior and inferior ganglia. Within the inferior ganglion, the saccular neurons were clustered in the anterior part. In the superior ganglion, the saccular neurons were widely scattered throughout the whole ganglion with more numerous neurons at the posterior half. Small and large neurons were labeled from all endorgans. Examination of the fiber trajectory within the superior division of the vestibular nerve showed no clear lamination of the fibers innervating the different endorgans. These results demonstrate an overlapping pattern between the different populations within the superior ganglion, while in the inferior ganglion, the posterior canal and saccular neurons show tighter clustering but incomplete segregation. This distribution implies that the ganglion cells are assigned for their target during development in a stochastic rather than topographical fashion.

  5. Treatment of temporomandibular joint ganglion cyst.

    Science.gov (United States)

    Wu, Chao-I; Liu, Ka-Wai; Hsu, Yung-Chang; Chiang, I-Ping; Chang, Sophia Chia-Ning

    2011-09-01

    Ganglion cysts of the temporomandibular joint are very rare and always misdiagnosed as synovial cyst, parotid gland tumor, or other cystic lesions. They present with pain, swelling, or dysfunction. Image studies could facilitate to identify the tumor mass from the adjacent soft tissue, but a definitive diagnosis could be made from the pathologic report.A 59-year-old woman presented to the clinics with a chief complaint of a painless swelling mass in the right preauricular region of 3-month duration. Computed tomography was performed, which showed a small radiolucent lesion adjacent to the right condyle. Local excision was performed, and the specimen was sent for histologic examination.Microscopic examination showed a cystic space walled by dense fibrous connective tissue without epithelial or endothelial lining. Immunohistochemical staining of these lining cells showed positivity for vimentin and negativity for cytokeratin. These findings were consistent with the diagnosis of ganglion cyst.Ganglion cysts present as unilobulate or multilobulate cysts that arise from the collagenous tissue and is filled with highly viscous fluid. It does not communicate with the joint cavity. In contrast, synovial cyst is a true cyst lined by cuboidal or flattened cells from the synoviocytes and is filled with gelatinous fluid. It may or may not communicate with the joint cavity. Excision is the treatment of choice of symptomatic cystic lesions. Incomplete excision of these lesions may cause further recurrence or infection. Thus, injection of hydrocortisone or aspiration may be considered as an alternative management.

  6. Alterations of neurochemical expression of the coeliac-superior mesenteric ganglion complex (CSMG) neurons supplying the prepyloric region of the porcine stomach following partial stomach resection.

    Science.gov (United States)

    Palus, Katarzyna; Całka, Jarosław

    2016-03-01

    The purpose of the present study was to determine the response of the porcine coeliac-superior mesenteric ganglion complex (CSMG) neurons projecting to the prepyloric area of the porcine stomach to peripheral neuronal damage following partial stomach resection. To identify the sympathetic neurons innervating the studied area of stomach, the neuronal retrograde tracer Fast Blue (FB) was applied to control and partial stomach resection (RES) groups. On the 22nd day after FB injection, following laparotomy, the partial resection of the previously FB-injected stomach prepyloric area was performed in animals of RES group. On the 28th day, all animals were re-anaesthetized and euthanized. The CSMG complex was then collected and processed for double-labeling immunofluorescence. In control animals, retrograde-labelled perikarya were immunoreactive to tyrosine hydroxylase (TH), dopamine β-hydroxylase (DβH), neuropeptide Y (NPY) and galanin (GAL). Partial stomach resection decreased the numbers of FB-positive neurons immunopositive for TH and DβH. However, the strong increase of NPY and GAL expression, as well as de novo-synthesis of neuronal nitric oxide synthase (nNOS) and leu5-Enkephalin (LENK) was noted in studied neurons. Furthermore, FB-positive neurons in all pigs were surrounded by a network of cocaine- and amphetamine-regulated transcript peptide (CART)-, calcitonin gene-related peptide (CGRP)-, and substance P (SP)-, vasoactive intestinal peptide (VIP)-, LENK- and nNOS- immunoreactive nerve fibers. This may suggest neuroprotective contribution of these neurotransmitters in traumatic responses of sympathetic neurons to peripheral axonal damage. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Vascular mechanism of axonal degeneration in peripheral nerves in hemiplegic sides after cerebral hemorrhage: An experimental study

    Directory of Open Access Journals (Sweden)

    Bayram Ednan

    2008-04-01

    Full Text Available Abstract Background Though retrograde neuronal death and vascular insufficiency have been well established in plegics following intracerebral hemorrhage, the effects of plegia on arterial nervorums of peripheral nerves have not been reported. In this study, the histopathological effects of the intracerebral hemorrhage on the dorsal root ganglions and sciatic nerves via affecting the arterial nervorums were investigated. Methods This study was conducted on 13 male hybrid rabbits. Three animals were taken as control group and did not undergo surgery. The remaining 10 subjects were anesthetized and were injected with 0.50 ml of autologous blood into their right sensory-motor region. All rabbits were followed-up for two months and then sacrificed. Endothelial cell numbers and volume values were estimated a three dimensionally created standardized arterial nervorums model of lumbar 3. Neuron numbers of dorsal root ganglions, and axon numbers in the lumbar 3 nerve root and volume values of arterial nervorums were examined histopathologically. The results were analyzed by using a Mann-Whitney-U test. Results Left hemiplegia developed in 8 animals. On the hemiplegic side, degenerative vascular changes and volume reduction in the arterial nervorums of the sciatic nerves, neuronal injury in the dorsal root ganglions, and axonal injury in the lumbar 3 were detected. Statistical analyses showed a significant correlation between the normal or nonplegic sides and plegic sides in terms of the neurodegeneration in the dorsal root ganglions (p Conclusion Intracerebral hemorrhage resulted in neurodegeneration in the dorsal root ganglion and axonolysis in the sciatic nerves, endothelial injury, and volume reduction of the arterial nervorums in the sciatic nerves. The interruption of the neural network connection in the walls of the arterial nervorums in the sciatic nerves may be responsible for circulation disorders of the arterial nervorums, and arterial

  8. Wallerian-like axonal degeneration in the optic nerve after excitotoxic retinal insult: an ultrastructural study

    Directory of Open Access Journals (Sweden)

    Saggu Sarabjit K

    2010-08-01

    Full Text Available Abstract Background Excitotoxicity is involved in the pathogenesis of a number neurodegenerative diseases, and axonopathy is an early feature in several of these disorders. In models of excitotoxicity-associated neurological disease, an excitotoxin delivered to the central nervous system (CNS, could trigger neuronal death not only in the somatodendritic region, but also in the axonal region, via oligodendrocyte N-methyl-D-aspartate (NMDA receptors. The retina and optic nerve, as approachable regions of the brain, provide a unique anatomical substrate to investigate the "downstream" effect of isolated excitotoxic perikaryal injury on central nervous system (CNS axons, potentially providing information about the pathogenesis of the axonopathy in clinical neurological disorders. Herein, we provide ultrastructural information about the retinal ganglion cell (RGC somata and their axons, both unmyelinated and myelinated, after NMDA-induced retinal injury. Male Sprague-Dawley rats were killed at 0 h, 24 h, 72 h and 7 days after injecting 20 nM NMDA into the vitreous chamber of the left eye (n = 8 in each group. Saline-injected right eyes served as controls. After perfusion fixation, dissection, resin-embedding and staining, ultrathin sections of eyes and proximal (intraorbital and distal (intracranial optic nerve segments were evaluated by transmission electron tomography (TEM. Results TEM demonstrated features of necrosis in RGCs: mitochondrial and endoplasmic reticulum swelling, disintegration of polyribosomes, rupture of membranous organelle and formation of myelin bodies. Ultrastructural damage in the optic nerve mimicked the changes of Wallerian degeneration; early nodal/paranodal disturbances were followed by the appearance of three major morphological variants: dark degeneration, watery degeneration and demyelination. Conclusion NMDA-induced excitotoxic retinal injury causes mainly necrotic RGC somal death with Wallerian-like degeneration of the

  9. Volumetric MRI for evaluation of regional pattern and progression of neocortical degeneration in Alzheimer's disease; MR-Volumetrie zur Darstellung von Verteilung und zeitlicher Abfolge neokortikaler Degeneration bei Morbus Alzheimer

    Energy Technology Data Exchange (ETDEWEB)

    Leinsinger, G. [Institut fuer Klinische Radiologie, Klinikum der Ludwig-Maximilians-Universitaet Muenchen, Muenchen (Germany); Institut fuer Klinische Radiologie, LMU Muenchen, Ziemssenstrasse 1, 80336, Muenchen (Germany); Teipel, S.; Pruessner, J.; Hampel, H. [Klinik fuer Psychiatrie, Ludwig-Maximilians-Universitaet Muenchen, Muenchen (Germany); Wismueller, A.; Born, C.; Meindl, T.; Flatz, W.; Schoenberg, S.; Reiser, M. [Institut fuer Klinische Radiologie, Klinikum der Ludwig-Maximilians-Universitaet Muenchen, Muenchen (Germany)

    2003-07-01

    Volumetric analysis of the corpus callosum and hippocampus using MRI in Alzheimer's disease (AD) to evaluate the regional pattern and progression of neocortical neurodegeneration. In subsequent studies we investigated patients with AD and healthy controls. Volumetry was based on MRI-data from a sagittal 3D T1w-gradient echo sequence. The corpus callosum (CC) was measured in a midsagittal slice, and subdivided into 5 subregions. Volumetry of the hippocampus/amygdala-formation (HAF) was performed by segmentation in coronary reoriented slices. In AD patients we found a significant atrophy in the rostrum und splenium of CC. The atrophy was correlated with the severity of dementia, but no correlation was found with the load of white matter lesions. In comparison with {sup 18}FDG-PET, we found a significant correlation of regional CC-atrophy with the regional decline of cortical glucose metabolism. A ROC-analysis demonstrated no significant differences in the diagostic accuracy of HAF volumetry and regional CC volumetry of the splenium (region C5) even in mild stages of dementia. Regional atrophy of CC can be used as a marker of neocortical degeneration even in early stages of dementia in AD. (orig.) [German] Volumetrische Analyse des Corpus callosum und Hippokampus mittels MRT bei der Alzheimer-Erkrankung (AD), mit dem Ziel die regionale Verteilung und Progression der neokortikalen relativ zur allokortikalen Neurodegeneration zu erfassen. In mehreren Studienabschnitten wurden Patienten mit AD und gesunde Kontrollen untersucht. Als Grundlage fuer die Volumetrie diente eine sagittale 3D-T1w-Gradientenechosequenz. Die Vermessung des Corpus callosum (CC) erfolgte in der mittsagittalen Schicht, wobei 5 Subregionen definiert wurden. Die Volumetrie des Hippokampus-Amygdala-Komplexes (HAK) wurde durch Segmentierung an koronar reorientierten Schichten durchgefuehrt. Bei Patienten mit AD fand sich eine signifikante Atrophie in Rostrum und Splenium des CC. Dabei zeigte sich

  10. Use of conserved genomic regions and degenerate primers in a PCR-based assay for the detection of members of the genus Caulimovirus.

    Science.gov (United States)

    Pappu, H R; Druffel, K L

    2009-04-01

    The genus Caulimovirus consists of several distinct virus species with a double-stranded DNA genome that infect diverse plant species. A comparative analysis of the sequences of known Caulimovirus species revealed two regions that are conserved in all Caulimovirus species with the exception of Strawberry vein banding virus. Degenerate primers based on these two regions were designed and tested in a polymerase chain reaction-based assay for broad spectrum detection of members of this genus. Cauliflower mosaic virus, Figwort mosaic virus and three distinct caulimoviruses associated with dahlia (Dahlia variabilis) were used to show the utility of this test in detecting diverse caulimoviruses. The primer pair gave an amplicon of expected size (840bp). Amplicons from each virus were cloned and sequenced to verify their identity. The primer pair and the PCR assay provide approach for the broad spectrum detection of several members of the genus Caulimovirus.

  11. Diversity in spatial scope of contrast adaptation among mouse retinal ganglion cells.

    Science.gov (United States)

    Khani, Mohammad Hossein; Gollisch, Tim

    2017-12-01

    Retinal ganglion cells adapt to changes in visual contrast by adjusting their response kinetics and sensitivity. While much work has focused on the time scales of these adaptation processes, less is known about the spatial scale of contrast adaptation. For example, do small, localized contrast changes affect a cell's signal processing across its entire receptive field? Previous investigations have provided conflicting evidence, suggesting that contrast adaptation occurs either locally within subregions of a ganglion cell's receptive field or globally over the receptive field in its entirety. Here, we investigated the spatial extent of contrast adaptation in ganglion cells of the isolated mouse retina through multielectrode-array recordings. We applied visual stimuli so that ganglion cell receptive fields contained regions where the average contrast level changed periodically as well as regions with constant average contrast level. This allowed us to analyze temporal stimulus integration and sensitivity separately for stimulus regions with and without contrast changes. We found that the spatial scope of contrast adaptation depends strongly on cell identity, with some ganglion cells displaying clear local adaptation, whereas others, in particular large transient ganglion cells, adapted globally to contrast changes. Thus, the spatial scope of contrast adaptation in mouse retinal ganglion cells appears to be cell-type specific. This could reflect differences in mechanisms of contrast adaptation and may contribute to the functional diversity of different ganglion cell types. NEW & NOTEWORTHY Understanding whether adaptation of a neuron in a sensory system can occur locally inside the receptive field or whether it always globally affects the entire receptive field is important for understanding how the neuron processes complex sensory stimuli. For mouse retinal ganglion cells, we here show that both local and global contrast adaptation exist and that this diversity in

  12. ["Point by point" approach to structure-function correlation of glaucoma on the ganglion cell complex in the posterior pole].

    Science.gov (United States)

    Zeitoun, M

    2017-01-01

    the two previous ones. In pathologically thin areas, the distribution of these three functional groups seems to correspond to the progression of glaucomatous visual degradation, including a period of resistance, a period of rapid decline, finally leading to complete functional loss. In the studied area, the analysis of retinal ganglion cell complex is relevant to identify areas which are still functional when they exceed 70 microns. Scotomas correspond to the thin areas less than 70 microns. The functionality of areas which are pathologically thinned by glaucomatous degeneration is not correlated to their thickness. In the future, the correlation between structure and function, currently "regional" may be realized "point by point" once automation of the visual field superimposition is made available for the ganglion cell complex. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  13. Differential regional cerebral glucose metabolism in clinical syndromes of frontotemporal lobar degeneration: a study with FDG PET

    Energy Technology Data Exchange (ETDEWEB)

    Park, J. M.; Cho, S. S.; Na, D. L.; Lee, K. H.; Choi, Y.; Choe, Y. S.; Kim, B. T.; Kim, S. E. [College of Medicine, Sungkyunkwan Univ., Seoul (Korea, Republic of)

    2001-07-01

    Frontotemporal lobar degeneration( FTLD) is the third most common dementia, following Alzheimer's disease and Lewy body disease. Four prototypic neurobehavioral syndromes can be produced by FTLD: frontotemporal dementia (FTD), frontotemporal dementia with motor neuron disease (MND), semantic dementia (SD), and progressive aphasia (PA). We investigated patterns of metabolic impairment in patient with FTLD presented with four different clinical syndromes. We analysed glucose metabolic patterns on FDG PET images obtained from 34 patients with a clinical diagnosis of FTLD (19 FTD, 6 MND, 6 SD, and 3 PA, according to a consensus criteria for clinical syndromes associated with FTLD) and 7 age-matched healthy controls using SPM99. Patients with FTD had metabolic deficit in the left frontal cortex and bilateral anterior temporal cortex. Hypometabolism in the bilateral premotor are was shown in patients with MND. Patients with SD had metabolic deficit in the left posterior temporal cortex including Wernicke's area, while hypometabolism in the bilateral inferior frontal gyrus including Broca's area and left angular gyrus was seen in patients with PA. These metabolic patterns were well correlated with clinical features of FTLD syndromes. These data provide a biochemical basis of clinical classification of FTLD. FDG PET may help evaluate and classify patients with FTLD.

  14. Degeneration of articular cartilage in osteonecrosis of the femoral head begins at the necrotic region after collapse: a preliminary study using T1 rho MRI

    Energy Technology Data Exchange (ETDEWEB)

    Sonoda, Kazuhiko; Motomura, Goro; Nakashima, Yasuharu [Kyushu University, Department of Orthopaedic Surgery, Graduate School of Medical Sciences, Higashi-ku, Fukuoka (Japan); Kawanami, Satoshi; Takayama, Yukihisa; Honda, Hiroshi [Kyushu University, Department of Clinical Radiology, Graduate School of Medical Sciences, Higashi-ku, Fukuoka (Japan); Yamamoto, Takuaki [Fukuoka University, Department of Orthopaedic Surgery, Faculty of Medicine, Jonan-ku, Fukuoka (Japan)

    2017-04-15

    The purpose of this study is to evaluate the role of collapse on the degeneration of articular cartilage in patients with osteonecrosis of the femoral head (ONFH). Sixteen hips in 12 patients (four men, eight women; mean age, 34.8 years) with a history of systemic corticosteroid treatment were studied using T1 rho magnetic resonance imaging (MRI). Six hips had collapsed ONFH, five had non-collapsed ONFH, and five had no osteonecrosis (controls). Using oblique coronal images, we divided the articular surface of necrotic femoral heads into a region just above the necrotic bone (necrotic zone) and another above the living bone (living zone). T1 rho value was evaluated for each zone. The mean T1 rho value in the necrotic zone was significantly higher in the collapsed ONFH group (48.4 ± 2.7 ms) than in the non-collapsed ONFH group (41.0 ± 0.9 ms). In the collapsed ONFH group, the mean T1 rho value was significantly higher in the necrotic zone (48.4 ± 2.7 ms) than in the living zone (43.5 ± 2.5 ms). In the non-collapsed ONFH group, there was no significant difference between the mean T1 rho values of the necrotic and living zones. In the collapsed ONFH group, the mean T1 rho value of the necrotic zone and the interval from pain onset to the MRI examination were positively correlated. The current T1 rho MRI study suggested that the degeneration of articular cartilage in ONFH begins at the necrotic region after collapse. (orig.)

  15. Degeneration of articular cartilage in osteonecrosis of the femoral head begins at the necrotic region after collapse: a preliminary study using T1 rho MRI

    International Nuclear Information System (INIS)

    Sonoda, Kazuhiko; Motomura, Goro; Nakashima, Yasuharu; Kawanami, Satoshi; Takayama, Yukihisa; Honda, Hiroshi; Yamamoto, Takuaki

    2017-01-01

    The purpose of this study is to evaluate the role of collapse on the degeneration of articular cartilage in patients with osteonecrosis of the femoral head (ONFH). Sixteen hips in 12 patients (four men, eight women; mean age, 34.8 years) with a history of systemic corticosteroid treatment were studied using T1 rho magnetic resonance imaging (MRI). Six hips had collapsed ONFH, five had non-collapsed ONFH, and five had no osteonecrosis (controls). Using oblique coronal images, we divided the articular surface of necrotic femoral heads into a region just above the necrotic bone (necrotic zone) and another above the living bone (living zone). T1 rho value was evaluated for each zone. The mean T1 rho value in the necrotic zone was significantly higher in the collapsed ONFH group (48.4 ± 2.7 ms) than in the non-collapsed ONFH group (41.0 ± 0.9 ms). In the collapsed ONFH group, the mean T1 rho value was significantly higher in the necrotic zone (48.4 ± 2.7 ms) than in the living zone (43.5 ± 2.5 ms). In the non-collapsed ONFH group, there was no significant difference between the mean T1 rho values of the necrotic and living zones. In the collapsed ONFH group, the mean T1 rho value of the necrotic zone and the interval from pain onset to the MRI examination were positively correlated. The current T1 rho MRI study suggested that the degeneration of articular cartilage in ONFH begins at the necrotic region after collapse. (orig.)

  16. Macular degeneration (image)

    Science.gov (United States)

    Macular degeneration is a disease of the retina that affects the macula in the back of the eye. ... see fine details. There are two types of macular degeneration, dry and wet. Dry macular degeneration is more ...

  17. American Macular Degeneration Foundation

    Science.gov (United States)

    ... Policy Disclaimer Contact Us Donate Store The American Macular Degeneration Foundation The American Macular Degeneration Foundation (AMDF) is ... Ed Asner Video Clip An Inspiring Her-story Macular Degeneration is the leading cause of vision loss, affecting ...

  18. Sphenopalatine ganglion neuromodulation in migraine

    DEFF Research Database (Denmark)

    Khan, Sabrina; Schoenen, Jean; Ashina, Messoud

    2014-01-01

    OBJECTIVE: The objective of this article is to review the prospect of treating migraine with sphenopalatine ganglion (SPG) neurostimulation. BACKGROUND: Fuelled by preliminary studies showing a beneficial effect in cluster headache patients, the potential of treating migraine with neurostimulation...... has gained increasing interest within recent years, as current treatment strategies often fail to provide adequate relief from this debilitating headache. Common migraine symptoms include lacrimation, nasal congestion, and conjunctival injection, all parasympathetic manifestations. In addition......, studies have suggested that parasympathetic activity may also contribute to the pain of migraineurs. The SPG is the largest extracranial parasympathetic ganglion of the head, innervating the meninges, lacrimal gland, nasal mucosa, and conjunctiva, all structures involved in migraine with cephalic...

  19. Cerebral blood flow and metabolism in patients with aphasia due to basal ganglionic lesion

    International Nuclear Information System (INIS)

    Kitamura, Shin; Kato, Toshiaki; Ujike, Takashi; Kuroki, Soemu; Terashi, Akiro

    1987-01-01

    Cerebral blood flow and metabolism in right handed eight patients with subcortical lesion and aphasia were measured to investigate the correlation between aphasia and functional changes in cerebral blood flow (CBF) and cerebral oxygen consumption (CMRO 2 ) in the cortex and the basal ganglionic region. All patients had no lesion in the cortex, but in the basal ganglionic region (putamen, caudate nucleus, internal capsule, and periventricular white matter) on CT images. Patients with bilateral lesion were excluded in this study. Six patients with cerebral infarction in the left basal ganglionic region and two patients with the left putammal hemorrhage were examined. Five patients had non fluent Broca's type speech, two patients had poor comprehension, fluent Wernicke-type speech and one patient was globally aphasic. CBF, CMRO 2 , and oxygen extraction fraction were measured by the positron emission tomography using 15 O 2 , C 15 O 2 inhalation technique. In addition to reduction of CBF and CMRO 2 in the basal ganglionic region, CBF and CMRO 2 decreased in the left frontal cortex especially posterior part in four patients with Broca's aphasia. In two patients with Wernicke type aphasia, CBF and CMRO 2 decreased in the basal ganglionic region and the left temporal cortex. In a globally aphasic patient, marked reduction of CBF and CMRO 2 was observed in the left frontal and temporal cortex, in addition to the basal ganglionic region. These results suggest that dysfunction of cortex as well as that of basal ganglionic region might be related to the occurence of aphasia. However, in one patient with Broca's ahasia, CBF and CMRO 2 were preserved in the cortex and metabolic reduction was observed in only basal ganglia. This case indicates the relation between basal ganglionic lesion and the occurrence of aphasia. These results suggest that measurements of cerebral blood flow and metabolism were necessary to study the responsible lesion for aphasia. (author)

  20. [Regional Differences in the Care of Patients with Neovascular Age-Related Macular Degeneration, Based on the Non-Interventional OCEAN Study].

    Science.gov (United States)

    Ziemssen, F; Hufenbach, U; Wiedon, A; Scheffler, M; Bertelmann, T

    2016-12-01

    Background: The main cause of blindness in the elderly in Germany is neovascular age-related macular degeneration (nAMD). In the non-interventional OCEAN study, data were prospectively collected on the routine clinical care of patients treated with the drug ranibizumab. Patients: As part of an interim analysis within the ongoing study (NCT02194803), stratification was performed by the 17 regions of the German associations of panel physicians and by areas of different population density. Only data were analysed for patients for whom the first treatment with ranibizumab was documented. Results: A total of 5,606 patients were documented. The present manuscript reviews 2,658 treatment-naive patients with nAMD, documented by 324 ophthalmologists. Most patients receiving an intravitreal injection were female (60 %). The average patient was aged 77.7 ± 8.2 years at study start. The great majority of patients had statutory health insurance (91 %). At baseline, fluorescein angiography (FLA) was performed for 72 % of patients, while optical coherence tomography (OCT) was carried out for 76 %. A combination of both was performed for 54 % of patients, varying regionally from 26 % (Saxony-Anhalt) to 100 % (Berlin). The average waiting time between the first examination and the first injection was 20.0 ± 18.5 days. With different statistical models (ANOVA adjusted, with/without interactions), significant effects on treatment delay were found for district type (population density), federal state and type of specialist. Conclusion: No major regional differences were observed in the demographic characteristics of the patient population. The main regional disparities in the care of nAMD patients were in the application of diagnostic methods and the waiting times between the first examination and the first drug administration. The regional variations in treatment delays could clearly influence the risk of worse functional outcome. Georg Thieme Verlag KG

  1. Spatially and Temporally Regulated NRF2 Gene Therapy Using Mcp-1 Promoter in Retinal Ganglion Cell Injury

    Directory of Open Access Journals (Sweden)

    Kosuke Fujita

    2017-06-01

    Full Text Available Retinal ganglion cell degeneration triggered by axonal injury is believed to underlie many ocular diseases, including glaucoma and optic neuritis. In these diseases, retinal ganglion cells are affected unevenly, both spatially and temporally, such that healthy and unhealthy cells coexist in different patterns at different time points. Herein, we describe a temporally and spatially regulated adeno-associated virus gene therapy aiming to reduce undesired off-target effects on healthy retinal neurons. The Mcp-1 promoter previously shown to be activated in stressed retinal ganglion cells following murine optic nerve injury was combined with the neuroprotective intracellular transcription factor Nrf2. In this model, Mcp-1 promoter-driven NRF2 expression targeting only stressed retinal ganglion cells showed efficacy equivalent to non-selective cytomegalovirus promoter-driven therapy for preventing cell death. However, cytomegalovirus promoter-mediated NRF2 transcription induced cellular stress responses and death of Brn3A-positive uninjured retinal ganglion cells. Such undesired effects were reduced substantially by adopting the Mcp-1 promoter. Combining a stress-responsive promoter and intracellular therapeutic gene is a versatile approach for specifically targeting cells at risk of degeneration. This strategy may be applicable to numerous chronic ocular and non-ocular conditions.

  2. Fine structure of the ganglion of Cephalodiscus gracilis (Pterobranchia, Hemichordata).

    Science.gov (United States)

    Rehkämper, G; Welsch, U; Dilly, P N

    1987-05-08

    The ganglion of Cephalodiscus gracilis M'Intosh 1882 is entirely intraepithelial and located in the dorsal epidermis immediately behind the tentacular apparatus that is formed by the mesosome (collar). A characteristic feature of the ganglion is a well-developed neuropile in which different types of nerve fibres can be discerned, many of which contain small granules with electron-dense contents. There are no glia-like cells in association with these fibres. Only slender basal processes of epidermal epithelial cells traverse the neuropile. In the depth of the epithelium the neuropile borders the epidermal basal lamina; apically it is covered by a layer of cell bodies, the majority of which belong to what appear to be ordinary ciliated epidermal cells. Besides these epidermal cells the perikarya of two additional types of cells, which are considered to be neurons, can be discerned. One type is characterised by many rough endoplasmic reticulum cisterns and mitochondria, the other by abundant small, electron-dense granules. The nuclei of these cells are comparatively pale and contain a prominent nucleolus. The neuron cell bodies do not form a distinct layer; but they are loosely distributed somewhat deeper than those of the ordinary epidermal cells. They probably send off an apical process to the epidermal surface and a basally directed one into the neuropile. The ganglion has been compared to the nervous systems in cnidarians, some spiralians, and especially other hemichordates, echinoderms, and chordates; it is found to be of primitive rather than degenerate nature. Furthermore, the possible functional significance of its close connection to the food-capturing tentacular apparatus is discussed.

  3. Stratification of alpha ganglion cells and ON/OFF directionally selective ganglion cells in the rabbit retina

    OpenAIRE

    ZHANG, JIAN; LI, WEI; HOSHI, HIDEO; MILLS, STEPHEN L.; MASSEY, STEPHEN C.

    2005-01-01

    The correlation between cholinergic sensitivity and the level of stratification for ganglion cells was examined in the rabbit retina. As examples, we have used ON or OFF α ganglion cells and ON/OFF directionally selective (DS) ganglion cells. Nicotine, a cholinergic agonist, depolarized ON/OFF DS ganglion cells and greatly enhanced their firing rates but it had modest excitatory effects on ON or OFF α ganglion cells. As previously reported, we conclude that DS ganglion cells are the most sens...

  4. Reduction of Endogenous Angiogenesis Inhibitors in Bruch’s Membrane of the Submacular Region in Eyes With Age-Related Macular Degeneration

    Science.gov (United States)

    Bhutto, Imran A.; Uno, Koichi; Merges, Carol; Zhang, Lei; McLeod, D. Scott; Lutty, Gerard A.

    2016-01-01

    Objectives To determine the relative levels of 3 potent inhibitors of angiogenesis (endostatin, pigment epithelium–derived factor, and thrombospondin 1) in the retinal pigment epithelium–Bruch’s membrane–choriocapillaris complex in the submacular region in aged control eyes and eyes with age-related macular degeneration (AMD). Methods Immunohistochemical analysis with antibodies against endostatin, pigment epithelium–derived factor, and thrombospondin 1 was performed on the macular region of aged control donor eyes (n=8; mean age, 79.8 years) and eyes with AMD (n=12; mean age, 83.9 years). Three independent masked observers scored the reaction product (scored from 0–7). Mean scores from the control eyes and the eyes with AMD were analyzed using 1-way analysis of variance and unpaired t test. Results In control eyes, strong immunoreactivity of all 3 inhibitors was observed in the retinal pigment epithelium–Bruch’s membrane–choriocapillaris complex. Immunoreactivity for endostatin, pigment epithelium–derived factor, and thrombospondin 1 in Bruch’s membrane was significantly lower in eyes with AMD compared with aged control eyes (analysis of variance, P=.003, P = .009, and P< .001, respectively). In the choriocapillaris, a significant reduction was observed in endostatin (analysis of variance, P=.02) and thrombospondin 1 (analysis of variance, P=.005) in eyes with AMD. Conclusions These findings suggest that endogenous angiogenesis inhibitors in the retinal pigment epithelium–Bruch’s membrane–choriocapillaris complex may provide a biochemical barrier for choroidal neovascular invasion. Clinical Relevance Decreased levels of angiogenic inhibitors at the retinal pigment epithelium–Bruch’s membrane–choriocapillaris complex in eyes with AMD make Bruch’s membrane vulnerable to choroidal neovascularization. PMID:18474778

  5. Regulation of Taurine transporter activity in cultured rat retinal ganglion cells and rat retinal Muller Cells

    International Nuclear Information System (INIS)

    Eissa, Laila A.; Smith, Sylvia B.; El-sherbeny, Amira A.

    2006-01-01

    Diabetic retinopathy is one of the most common complications of diabetes. The amino acid taurine is believed to play an antioxidant protective role in diabetic retinopathy through the scavenging of the reactive species. It is not well established whether taurine uptake is altered in retina cells during diabetic conditions. Thus, the present study was designed to investigate the changes in taurine transport in cultures of rat retinal Muller cells and rat retinal ganglion cells under conditions associated with diabetes. Taurine was abundantly taken up by retinal Muller cells and rat retinal ganglion cells under normal glycemic condition. Taurine was actively transported to rat Muller cells and rat retinal ganglion cells in a Na and Cl dependant manner. Taurine uptake further significantly elevated in both type of cells after the incubation with high glucose concentration. This effect could be attributed to the increase in osmolarity. Because Nitric Oxide (NO) is a molecule implicated in the pathogenesis of diabetes, we also determined the activity of taurine transporter in cultured rat retinal Muller cells and rat retinal ganglion cells in the presence of the NO donors, SIN-1 and SNAP. Taurine uptake was elevated above control value after 24-h incubation with low concentration of NO donors. We finally investigated the ability of neurotoxic glutamate to change taurine transporter activity in both types of cells. Uptake of taurine was significantly increased in rat retinal ganglion cells when only incubated with high concentration of glutamate. Our data provide evidence that taurine transporter is present in cultured rat retinal ganglion and Muller cells and is regulated by hyperosmolarity. The data are relevant to disease such as diabetes and neuronal degeneration where retinal cell volume may dramatically change. (author)

  6. Progress toward the maintenance and repair of degenerating retinal circuitry.

    Science.gov (United States)

    Vugler, Anthony A

    2010-01-01

    Retinal diseases such as age-related macular degeneration and retinitis pigmentosa remain major causes of severe vision loss in humans. Clinical trials for treatment of retinal degenerations are underway and advancements in our understanding of retinal biology in health/disease have implications for novel therapies. A review of retinal biology is used to inform a discussion of current strategies to maintain/repair neural circuitry in age-related macular degeneration, retinitis pigmentosa, and Type 2 Leber congenital amaurosis. In age-related macular degeneration/retinitis pigmentosa, a progressive loss of rods/cones results in corruption of bipolar cell circuitry, although retinal output neurons/photoreceptive melanopsin cells survive. Visual function can be stabilized/enhanced after treatment in age-related macular degeneration, but in advanced degenerations, reorganization of retinal circuitry may preclude attempts to restore cone function. In Type 2 Leber congenital amaurosis, useful vision can be restored by gene therapy where central cones survive. Remarkable progress has been made in restoring vision to rodents using light-responsive ion channels inserted into bipolar cells/retinal ganglion cells. Advances in genetic, cellular, and prosthetic therapies show varying degrees of promise for treating retinal degenerations. While functional benefits can be obtained after early therapeutic interventions, efforts should be made to minimize circuitry changes as soon as possible after rod/cone loss. Advances in retinal anatomy/physiology and genetic technologies should allow refinement of future reparative strategies.

  7. REDUCED GANGLION CELL VOLUME ON OPTICAL COHERENCE TOMOGRAPHY IN PATIENTS WITH GEOGRAPHIC ATROPHY.

    Science.gov (United States)

    Ramkumar, Hema L; Nguyen, Brian; Bartsch, Dirk-Uwe; Saunders, Luke J; Muftuoglu, Ilkay Kilic; You, Qisheng; Freeman, William R

    2017-11-07

    Geographic atrophy (GA) is the sequelae of macular degeneration. Automated inner retinal analysis using optical coherence tomography is flawed because segmentation software is calibrated for normal eyes. The purpose of this study is to determine whether ganglion cell layer (GCL) volume is reduced in GA using manual analysis. Nineteen eyes with subfoveal GA and 22 controls were selected for morphometric analyses. Heidelberg scanning laser ophthalmoscope optical coherence tomography images of the optic nerve and macula were obtained, and the Viewing Module was used to manually calibrate retinal layer segmentation. Retinal layer volumes in the central 3-mm and surrounding 6-mm diameter were measured. Linear mixed models were used for statistics. The GCL volume in the central 3 mm of the macula is less (P = 0.003), and the retinal nerve fiber layer volume is more (P = 0.02) in patients with GA when compared with controls. Ganglion cell layer volume positively correlated with outer nuclear layer volume (P = 0.020). The patients with geographic atrophy have a small significant loss of the GCL. Ganglion cell death may precede axonal loss, and increased macular retinal nerve fiber layer volumes are not indicative of GCL volume. Residual ganglion cell stimulation by interneurons may enable vision in patients with GA.

  8. Compression of the trigeminal ganglion produces prolonged nociceptive behavior in rats.

    Science.gov (United States)

    Ahn, Dong K; Lim, Eun J; Kim, Byung C; Yang, Gwi Y; Lee, Min K; Ju, Jin S; Han, Seung R; Bae, Yong C

    2009-07-01

    The present study is the first demonstration of prolonged nociceptive behavior in the trigeminal region following compression of the trigeminal ganglion in rats. Experiments were carried out on male Sprague-Dawley rats mounted onto a stereotaxic frame under pentobarbital sodium anesthesia. For compression of the trigeminal ganglion, a 4% agar solution (8microl) was injected into the trigeminal ganglion through a stainless steel injector (24 gauge), which extended 2mm beyond the end of a guide cannula (21 gauge). Following agar injection, the injector and guide cannula were removed. In the control group, rats were sham operated without agar injection. Air-puff thresholds (mechanical allodynia), pin prick responses (mechanical hyperalgesia), and spontaneous scratching behavior were examined 3 days before surgery and at 3, 7, 10, 14, 17, 21, 24, 30, and 40 days after surgery. Data were analyzed using a repeated measures ANOVA followed by multiple group comparisons using the LSD post-hoc test. Air-puff thresholds significantly decreased after compression of the trigeminal ganglion. Mechanical allodynia was established within 3 days and lasted beyond postoperative day 24. Mechanical hyperalgesia was also evident 3 days after compression and persisted until the 40th postoperative day. Although mechanical allodynia and hyperalgesia appeared bilaterally, the ipsilateral side was significantly more sensitive. Intraperitoneal treatment with carbamazepine significantly blocked mechanical allodynia produced by compression of the trigeminal ganglion. These findings suggest that prolonged nociceptive behavior following compression of the trigeminal ganglion may mimic trigeminal neuralgia in this animal model.

  9. Melanopsin Ganglion Cells Are the Most Resistant Retinal Ganglion Cell Type to Axonal Injury in the Rat Retina

    OpenAIRE

    Pérez de Sevilla Müller, Luis; Sargoy, Allison; Rodriguez, Allen R.; Brecha, Nicholas C.

    2014-01-01

    We report that the most common retinal ganglion cell type that remains after optic nerve transection is the M1 melanopsin ganglion cell. M1 ganglion cells are members of the intrinsically photosensitive retinal ganglion cell population that mediates non-image-forming vision, comprising ∼2.5% of all ganglion cells in the rat retina. In the present study, M1 ganglion cells comprised 1.7±1%, 28±14%, 55±13% and 82±8% of the surviving ganglion cells 7, 14, 21 and 60 days after optic nerve transect...

  10. Inner retinal change in a novel rd1-FTL mouse model of retinal degeneration

    Directory of Open Access Journals (Sweden)

    Ursula eGreferath

    2015-07-01

    Full Text Available While photoreceptor loss is the most devastating result of inherited retinal degenerations such as retinitis pigmentosa, inner retinal neurons also undergo significant alteration. Detailing these changes has become important as many vision restorative therapies target the remaining neurons. In this study, the rd1-Fos-Tau-LacZ (rd1-FTL mouse model was used to explore inner retinal change at a late stage of retinal degeneration, after the loss of photoreceptor nuclei. The rd1-FTL model carries a mutation in the phosphodiesterase gene, Pde6b, and an axonally targeted transgenic beta galactosidase reporter system under the control of the c-fos promoter. Retinae of transgenic rd1-FTL mice and control FTL animals aged 2 to 12 months were processed for indirect fluorescence immunocytochemistry. At 2 months of age, a time when the majority of photoreceptor nuclei are lost, there was negligible c-fos reporter (FTL expression, however, from 4 months, reporter expression was observed to increase within subpopulations of amacrine and ganglion cells within the central retina. These areas of inner retinal FTL expression coincided with regions that contained aberrant Müller cells. Specifically, these cells exhibited reduced glutamine synthetase and Kir4.1 immunolabelling, whilst showing evidence of proliferative gliosis (increased cyclinD1 and GFAP expression. These changes were limited to distinct regions where cone photoreceptor terminals were absent. Overall, these results highlight that distinct areas of the rd1-FTL central retina undergo significant glial alterations after cone photoreceptor loss. These areas coincide with up-regulation of the c-fos reporter in the inner retina, which may represent a change in neuronal function/plasticity. The rd1-FTL mouse is a useful model system to probe changes that occur in the inner retina at later stages of retinal degeneration.

  11. CT-guided injection for ganglion impar blockade: a radiological approach to the management of coccydynia

    Energy Technology Data Exchange (ETDEWEB)

    Datir, A., E-mail: apdatir@gmail.co [Jackson Memorial Hospital, Miami, FL (United States); Connell, D. [Royal National Orthopaedic Hospital NHS Trust, Stanmore, Middlesex (United Kingdom)

    2010-01-15

    -guided injection over those performed under fluoroscopy may include accurate and confident needle placement in the sacro-coccygeal region, ease of wide area coverage, lesser risk of complications due to inadvertent injections into the major pelvic structures, and increased likelihood of reaching the ganglion impar, especially in cases with anatomical variation in the ganglion impar location. These factors may have implications in the overall success rate of ganglion impar blockade.

  12. Retinal Ganglion Cell Distribution and Spatial Resolving Power in Deep-Sea Lanternfishes (Myctophidae)

    KAUST Repository

    De Busserolles, Fanny

    2014-01-01

    Topographic analyses of retinal ganglion cell density are very useful in providing information about the visual ecology of a species by identifying areas of acute vision within the visual field (i.e. areas of high cell density). In this study, we investigated the neural cell distribution in the ganglion cell layer of a range of lanternfish species belonging to 10 genera. Analyses were performed on wholemounted retinas using stereology. Topographic maps were constructed of the distribution of all neurons and both ganglion and amacrine cell populations in 5 different species from Nissl-stained retinas using cytological criteria. Amacrine cell distribution was also examined immunohistochemically in 2 of the 5 species using anti-parvalbumin antibody. The distributions of both the total neuron and the amacrine cell populations were aligned in all of the species examined, showing a general increase in cell density toward the retinal periphery. However, when the ganglion cell population was topographically isolated from the amacrine cell population, which comprised up to 80% of the total neurons within the ganglion cell layer, a different distribution was revealed. Topographic maps of the true ganglion cell distribution in 18 species of lanternfishes revealed well-defined specializations in different regions of the retina. Different species possessed distinct areas of high ganglion cell density with respect to both peak density and the location and/or shape of the specialized acute zone (i.e. elongated areae ventro-temporales, areae temporales and large areae centrales). The spatial resolving power was calculated to be relatively low (varying from 1.6 to 4.4 cycles per degree), indicating that myctophids may constitute one of the less visually acute groups of deep-sea teleosts. The diversity in retinal specializations and spatial resolving power within the family is assessed in terms of possible ecological functions and evolutionary history.

  13. Degenerate Euler zeta function

    OpenAIRE

    Kim, Taekyun

    2015-01-01

    Recently, T. Kim considered Euler zeta function which interpolates Euler polynomials at negative integer (see [3]). In this paper, we study degenerate Euler zeta function which is holomorphic function on complex s-plane associated with degenerate Euler polynomials at negative integers.

  14. Transsacrococcygeal approach to ganglion impar block for treatment of chronic coccygodynia after spinal arachnoid cyst removal

    Science.gov (United States)

    Cha, Young Deog; Yang, Chun Woo; Han, Jung Uk; Song, Jang Ho; Na, WonJu; Oh, Sora; Kim, Byung-Gun

    2016-01-01

    Abstract Background: Coccygodynia is a pain in the region of the coccyx that radiates to the sacral, perineal area. The cause of the pain is often unknown. Coccygodynia is diagnosed through the patient's past history, a physical examination, and dynamic radiographic study, but the injection of local anesthetics or a diagnostic nerve blockade are needed to distinguish between somatic, neuropathic, and combined pain. Ganglion impar is a single retroperitoneal structure made of both paravertebral sympathetic ganglions. Although there are no standard guidelines for the treatment of coccygodynia, ganglion impar blockade is one of the effective options for treatment. Methods: Here, we report a 42-year-old female patient presenting with severe pain in the coccygeal area after spinal arachnoid cyst removal. Results: Treatment involved neurolysis with absolute alcohol on the ganglion impar through the transsacrococcygeal junction. Pain was relieved without any complications. Conclusion: Our case report offers the ganglion impar blockade using the transsacrococcygeal approach with absolute alcohol can improve intractable coccydynia. PMID:27684866

  15. Case report: intra-tendinous ganglion of the anterior cruciate ligament in a young footballer

    Directory of Open Access Journals (Sweden)

    Watson Thomas P

    2006-11-01

    Full Text Available Abstract A 20-year-old male medical student and keen rugby player presented with a 12-month history of progressively worsening right knee pain and stiffness with no history of trauma. Clinical examination revealed effusion and posterior knee pain exacerbated by end range movement and an extension lag of 15 degrees. Physiotherapy to improve the range of motion proved unsuccessful. Magnetic resonance imaging showed that the ACL was grossly thickened and displaced by material reported as mucoid in nature. There were also areas of focally high signal in relation to its tibial attachment and intra osseous small cysts. Arthroscopic examination revealed a ganglion related to the tibial attachment of the ACL and gross thickening and discoloration of the ACL. Biopsies were taken showing foci of mucoid degeneration in the ACL. A large intra-ACL mass of brownish coloured tissue was excised arthroscopically. Already at 2 weeks follow up the patient had greatly improved range of movement and was pain free. However, upon returning to rugby, joint instability was noticed and a tear of the ACL was confirmed. This rare clinical condition can be diagnosed with MRI and arthroscopic debridement effectively relieves symptoms. This case report illustrates that augmentation or reconstruction may end up being the definitive treatment for athletes. It may also offer some support to the argument that mucoid degeneration and ganglion cyst formation share a similar pathogenesis to intra-osseous cyst formation.

  16. Piriformis ganglion: An uncommon cause of sciatica.

    Science.gov (United States)

    Park, J H; Jeong, H J; Shin, H K; Park, S J; Lee, J H; Kim, E

    2016-04-01

    Sciatica can occur due to a spinal lesion, intrapelvic tumor, diabetic neuropathy, and rarely piriformis syndrome. The causes of piriformis syndrome vary by a space-occupying lesion. A ganglionic cyst can occur in various lesions in the body but seldom around the hip joint. In addition, sciatica due to a ganglionic cyst around the hip joint has been reported in one patient in Korea who underwent surgical treatment. We experienced two cases of sciatica from a piriformis ganglionic cyst and we report the clinical characterics and progress after non-operative treatment by ultrasonography-guided aspiration. The two cases were diagnosed by magnetic resonance imaging and were treated by ultrasonography-guided aspiration. We followed the patients for more than 6months. The symptoms of piriformis syndrome from the ganglion improved following aspiration and this conservative treatment is a treatment method that can be used without extensive incision or cyst excision. Level IV historical case. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  17. A Case of Corticobasal Degeneration Studied with Positron Emission Tomography

    Directory of Open Access Journals (Sweden)

    H. Nagasawa

    1993-01-01

    Full Text Available We measured cerebral blood flow, oxygen metabolism, glucose utilization, and dopamine metabolism in the brain of a patient with corticobasal degeneration using positron emission tomography (PET. The clinical picture is distinctive, comprising features referable to both cortical and basal ganglionic dysfunction. Brain imagings of glucose and dopamine metabolism can demonstrate greater abnormalities in the cerebral cortex and in the striatum contralateral to the more affected side than those of blood flow and oxygen metabolism. This unique combination study measuring both cerebral glucose utilization and dopamine metabolism in the nigrostriatal system can provide efficient information about the dysfunctions which are correlated with individual clinical symptoms, and this study is essential to diagnosis of corticobasal degeneration.

  18. Degenerate nonlinear diffusion equations

    CERN Document Server

    Favini, Angelo

    2012-01-01

    The aim of these notes is to include in a uniform presentation style several topics related to the theory of degenerate nonlinear diffusion equations, treated in the mathematical framework of evolution equations with multivalued m-accretive operators in Hilbert spaces. The problems concern nonlinear parabolic equations involving two cases of degeneracy. More precisely, one case is due to the vanishing of the time derivative coefficient and the other is provided by the vanishing of the diffusion coefficient on subsets of positive measure of the domain. From the mathematical point of view the results presented in these notes can be considered as general results in the theory of degenerate nonlinear diffusion equations. However, this work does not seek to present an exhaustive study of degenerate diffusion equations, but rather to emphasize some rigorous and efficient techniques for approaching various problems involving degenerate nonlinear diffusion equations, such as well-posedness, periodic solutions, asympt...

  19. Degenerate Gauss hypergeometric functions

    OpenAIRE

    Vidunas, Raimundas

    2004-01-01

    This is a study of terminating and ill-defined Gauss hypergeometric functions. Corresponding hypergeometric equations have a degenerate set of of 24 Kummer's solutions. We describe those solutions and relations between them.

  20. Effects of phenolic acid metabolites formed after chlorogenic acid consumption on retinal degeneration in vivo.

    Science.gov (United States)

    Jang, Holim; Choi, Yongsoo; Ahn, Hong Ryul; Jung, Sang Hoon; Lee, Chang Yong

    2015-10-01

    Although ingestion of coffee and its constituent chlorogenic acid (CGA) protects the retina from oxidative stress, the bioaccessibility and bioavailability of coffee metabolites are not well understood. The aim of this study was to determine which coffee metabolites reach the retina and protect against retinal degeneration. UPLC-MS/MS was used to detect CGA and coffee metabolites in the rat eye. The methyl thiazolyl tetrazolium assay and double staining with Hoechst and propidium iodide showed that CGA, caffeic acid (CA), and dihydrocaffeic acid (DHCA) protect retinal ganglion cells from hypoxia-induced damage. Western blots showed that treatment with coffee metabolites up-regulated anti-apoptotic proteins such as Bcl-2 and Bcl-XL and down-regulated pro-apoptotic proteins such as Bad, PARP, and cleaved caspase 3. Adult ICR mice were subjected to optic nerve crush-induced retinal ganglion cell death with intravitreal pre-treatment with coffee metabolites 1 day before and 1 h after the procedure. Retrograde Fluorogold(TM) labeling showed severe retinal ganglion cell loss after optic nerve crushing, and coffee metabolites significantly reduced damage to retinal ganglion cells. CGA and coffee metabolites, especially, CA, and DHCA, reach the eye, where they can significantly reduce apoptosis induced by hypoxia and optic nerve crush stress, and thus prevent retinal degeneration. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Retinal Ganglion Cell Loss in X-linked Adrenoleukodystrophy with anABCD1Mutation (Gly266Arg).

    Science.gov (United States)

    Ohkuma, Yasuhiro; Hayashi, Takaaki; Yoshimine, Syouyou; Tsuneoka, Hiroshi; Terao, Yoko; Akiyama, Masaharu; Ida, Hiroyuki; Ohashi, Toya; Okumura, Akihisa; Ebihara, Nobuyuki; Murakami, Akira; Shimozawa, Nobuyuki

    2014-01-01

    The authors here report a single case of a 10-year-old male patient who presented with severe vision loss associated with progressive demyelination. The patient was diagnosed with X-linked childhood cerebral adrenoleukodystrophy (ALD). Genetic analysis demonstrated a missense mutation (Gly266Arg) in exon 1 of the ABCD1 gene. His corrected visual acuity confirmed the absolute lack of light perception in both eyes. Funduscopy revealed severe pallor of the optic disc in both eyes. Spectral-domain optical coherence tomography showed thinning of the retinal ganglion cell and inner plexiform layers (GCL and IPL). Thinning of the GCL and IPL may be due to transneuronal retrograde degeneration of ganglion cells secondary to optic tract demyelination.

  2. Topographic prominence discriminator for the detection of short-latency spikes of retinal ganglion cells

    Science.gov (United States)

    Choi, Myoung-Hwan; Ahn, Jungryul; Park, Dae Jin; Lee, Sang Min; Kim, Kwangsoo; Cho, Dong-il Dan; Senok, Solomon S.; Koo, Kyo-in; Goo, Yong Sook

    2017-02-01

    Objective. Direct stimulation of retinal ganglion cells in degenerate retinas by implanting epi-retinal prostheses is a recognized strategy for restoration of visual perception in patients with retinitis pigmentosa or age-related macular degeneration. Elucidating the best stimulus-response paradigms in the laboratory using multielectrode arrays (MEA) is complicated by the fact that the short-latency spikes (within 10 ms) elicited by direct retinal ganglion cell (RGC) stimulation are obscured by the stimulus artifact which is generated by the electrical stimulator. Approach. We developed an artifact subtraction algorithm based on topographic prominence discrimination, wherein the duration of prominences within the stimulus artifact is used as a strategy for identifying the artifact for subtraction and clarifying the obfuscated spikes which are then quantified using standard thresholding. Main results. We found that the prominence discrimination based filters perform creditably in simulation conditions by successfully isolating randomly inserted spikes in the presence of simple and even complex residual artifacts. We also show that the algorithm successfully isolated short-latency spikes in an MEA-based recording from degenerate mouse retinas, where the amplitude and frequency characteristics of the stimulus artifact vary according to the distance of the recording electrode from the stimulating electrode. By ROC analysis of false positive and false negative first spike detection rates in a dataset of one hundred and eight RGCs from four retinal patches, we found that the performance of our algorithm is comparable to that of a generally-used artifact subtraction filter algorithm which uses a strategy of local polynomial approximation (SALPA). Significance. We conclude that the application of topographic prominence discrimination is a valid and useful method for subtraction of stimulation artifacts with variable amplitudes and shapes. We propose that our algorithm

  3. Learning LM Specificity for Ganglion Cells

    Science.gov (United States)

    Ahumada, Albert J.

    2015-01-01

    Unsupervised learning models have been proposed based on experience (Ahumada and Mulligan, 1990;Wachtler, Doi, Lee and Sejnowski, 2007) that allow the cortex to develop units with LM specific color opponent receptive fields like the blob cells reported by Hubel and Wiesel on the basis of visual experience. These models used ganglion cells with LM indiscriminate wiring as inputs to the learning mechanism, which was presumed to occur at the cortical level.

  4. Laenderyggens degeneration og radiologi

    DEFF Research Database (Denmark)

    Jacobsen, Steffen; Gosvig, Kasper Kjaerulf; Sonne-Holm, Stig

    2006-01-01

    Low back pain (LBP) is one of the most common conditions, and at the same time one of the most complex nosological entities. The lifetime prevalence is approximately 80%, and radiological features of lumbar degeneration are almost universal in adults. The individual risk factors for LBP and signi...... is cyclic: exacerbations relieved by asymptomatic periods. New imaging modalities, including the combination of MR imaging and multiplanar 3-D CT scans, have broadened our awareness of possible pain-generating degenerative processes of the lumbar spine other than disc degeneration....

  5. Imaging of corticobasal degeneration syndrome

    International Nuclear Information System (INIS)

    Koyama, Masamichi; Yagishita, Akira; Nakata, Yasuhiro; Hayashi, Masaharu; Bandoh, Mitsuaki; Mizutani, Toshio

    2007-01-01

    Diagnosing corticobasal degeneration is often difficult on the basis of clinical symptoms and radiological images. We aimed to clarify the imaging findings of corticobasal degeneration syndrome (CBDS). Included in the study were 16 patients (8 men, 8 women, 46-75 years old) with clinically diagnosed CBDS. We evaluated the patients' symptoms and signs, and MR and single-photon emission CT (SPECT) imaging findings. All the patients had cerebral atrophy. Asymmetric cerebral atrophy was observed in 13 patients (81%) predominantly contralateral to the side clinically more affected. Atrophy in the cerebral peduncle was observed in seven patients. FLAIR images showed hyperintensity in the subcortical white matter in the frontoparietal lobes in the clinically more affected side in 14 patients, and in the rolandic region in 13 patients. Asymmetric hypoperfusion in the frontoparietal lobes on SPECT images was observed in all of the patients, and in the basal ganglia in 11 patients. CBDS might be unique in showing hyperintensity in the subcortical white matter in the rolandic region on FLAIR images with asymmetric atrophy predominantly contralateral to the side clinically more severely affected. Asymmetric atrophy in the cerebral peduncle without signal abnormalities was also characteristic of CBDS. Atrophy in the midbrain tegmentum was also seen in patients with CBDS. (orig.)

  6. KYNA analogue SZR72 modifies CFA-induced dural inflammation- regarding expression of pERK1/2 and IL-1β in the rat trigeminal ganglion

    DEFF Research Database (Denmark)

    Lukács, M; Warfvinge, K; Kruse, L S

    2016-01-01

    BACKGROUND: Neurogenic inflammation has for decades been considered an important part of migraine pathophysiology. In the present study, we asked the question if administration of a novel kynurenic acid analogue (SZR72), precursor of an excitotoxin antagonist and anti-inflammatory substance, can...... modify the neurogenic inflammatory response in the trigeminal ganglion. METHODS: Inflammation in the trigeminal ganglion was induced by local dural application of Complete Freunds Adjuvant (CFA). Levels of phosphorylated MAP kinase pERK1/2 and IL-1β expression in V1 region of the trigeminal ganglion were...

  7. Kraepelin and degeneration theory.

    Science.gov (United States)

    Hoff, Paul

    2008-06-01

    Emil Kraepelin's contribution to the clinical and scientific field of psychiatry is recognized world-wide. In recent years, however, there have been a number of critical remarks on his acceptance of degeneration theory in particular and on his political opinion in general, which was said to have carried "overtones of proto-fascism" by Michael Shepherd [28]. The present paper discusses the theoretical cornerstones of Kraepelinian psychiatry with regard to their relevance for Kraepelin's attitude towards degeneration theory. This theory had gained wide influence not only in scientific, but also in philosophical and political circles in the last decades of the nineteenth century. There is no doubt that Kraepelin, on the one hand, accepted and implemented degeneration theory into the debate on etiology and pathogenesis of mental disorders. On the other hand, it is not appropriate to draw a simple and direct line from early versions of degeneration theory to the crimes of psychiatrists and politicians during the rule of national socialism. What we need, is a differentiated view, since this will be the only scientific one. Much research needs to be done here in the future, and such research will surely have a significant impact not only on the historical field, but also on the continuous debate about psychiatry, neuroscience and neurophilosophy.

  8. Isolation and Molecular Profiling of Primary Mouse Retinal Ganglion Cells: Comparison of Phenotypes from Healthy and Glaucomatous Retinas

    OpenAIRE

    Chintalapudi, Sumana R.; Djenderedjian, Levon; Stiemke, Andrew B.; Steinle, Jena J.; Jablonski, Monica M.; Morales-Tirado, Vanessa M.

    2016-01-01

    Loss of functional retinal ganglion cells (RGC) is an element of retinal degeneration that is poorly understood. This is in part due to the lack of a reliable and validated protocol for the isolation of primary RGCs. Here we optimize a feasible, reproducible, standardized flow cytometry-based protocol for the isolation and enrichment of homogeneous RGC with the Thy1.2hiCD48negCD15negCD57neg surface phenotype. A three-step validation process was performed by: (1) genomic profiling of 25-genes ...

  9. Rgcs1, a dominant QTL that affects retinal ganglion cell death after optic nerve crush in mice

    Directory of Open Access Journals (Sweden)

    Schlamp Cassandra L

    2008-07-01

    Full Text Available Abstract Background Intrinsic apoptosis of neuronal somas is one aspect of neurodegenerative diseases that can be influenced by genetic background. Genes that affect this process may act as susceptibility alleles that contribute to the complex genetic nature of these diseases. Retinal ganglion cell death is a defining feature of the chronic and genetically complex neurodegenerative disease glaucoma. Previous studies using an optic nerve crush procedure in inbred mice, showed that ganglion cell resistance to crush was affected by the Mendelian-dominant inheritance of 1–2 predicted loci. To assess this further, we bred and phenotyped a large population of F2 mice derived from a resistant inbred strain (DBA/2J and a susceptible strain (BALB/cByJ. Results Genome wide mapping of the F2 mice using microsatellite markers, detected a single highly significant quantitative trait locus in a 25 cM (58 Mb interval on chromosome 5 (Chr5.loc34-59 cM. No interacting loci were detected at the resolution of this screen. We have designated this locus as Retinal ganglion cell susceptible 1, Rgcs1. In silico analysis of this region revealed the presence of 578 genes or expressed sequence tags, 4 of which are highly expressed in the ganglion cell layer of the mammalian retina, and 2 of which are suspected susceptibility alleles in chronic neurodegenerative diseases. In addition, 25 genes contain 36 known single nucleotide polymorphisms that create nonsynonymous amino acid changes between the two parental strains. Collectively, this analysis has identified 7 potential candidate genes that may affect ganglion cell death. Conclusion The process of ganglion cell death is likely one of the many facets of glaucoma susceptibility. A novel dominant locus has been identified that affects sensitivity of ganglion cells to optic nerve crush. The allele responsible for this sensitivity may also be a susceptibility allele for glaucoma.

  10. Subchondral synovial cysts (intra-osseous ganglion)

    International Nuclear Information System (INIS)

    Graf, L.; Freyschmidt, J.

    1988-01-01

    Twelve cases of subchondral synovial cysts (intra-osseous ganglion) have been seen and their clinical features, radiological findings and differential diagnosis are described. The lesion is a benign cystic tumour-like mass in the subchondral portion of a synovial joint. Our findings in respect of age, sex and localisation are compared with those of other authors. The aetiology and pathogenesis of the lesion is not completely understood. There is an increased incidence in middle life and joints with high dynamic and static stress are favoured, particularly in the lower extremities. Chronic stress or microtrauma, causing damage to the involved joint, therefore appears to be a plausible explanation. (orig.) [de

  11. Decreased Expression of DREAM Promotes the Degeneration of Retinal Neurons

    Science.gov (United States)

    Chintala, Shravan; Cheng, Mei; Zhang, Xiao

    2015-01-01

    The intrinsic mechanisms that promote the degeneration of retinal ganglion cells (RGCs) following the activation of N-Methyl-D-aspartic acid-type glutamate receptors (NMDARs) are unclear. In this study, we have investigated the role of downstream regulatory element antagonist modulator (DREAM) in NMDA-mediated degeneration of the retina. NMDA, phosphate-buffered saline (PBS), and MK801 were injected into the vitreous humor of C57BL/6 mice. At 12, 24, and 48 hours after injection, expression of DREAM in the retina was determined by immunohistochemistry, western blot analysis, and electrophoretic mobility-shift assay (EMSA). Apoptotic death of cells in the retina was determined by terminal deoxynucleotidyl transferace dUTP nick end labeling (TUNEL) assays. Degeneration of RGCs in cross sections and in whole mount retinas was determined by using antibodies against Tuj1 and Brn3a respectively. Degeneration of amacrine cells and bipolar cells was determined by using antibodies against calretinin and protein kinase C (PKC)-alpha respectively. DREAM was expressed constitutively in RGCs, amacrine cells, bipolar cells, as well as in the inner plexiform layer (IPL). NMDA promoted a progressive decrease in DREAM levels in all three cell types over time, and at 48 h after NMDA-treatment very low DREAM levels were evident in the IPL only. DREAM expression in retinal nuclear proteins was decreased progressively after NMDA-treatment, and correlated with its decreased binding to the c-fos-DRE oligonucleotides. A decrease in DREAM expression correlated significantly with apoptotic death of RGCs, amacrine cells and bipolar cells. Treatment of eyes with NMDA antagonist MK801, restored DREAM expression to almost normal levels in the retina, and significantly decreased NMDA-mediated apoptotic death of RGCs, amacrine cells, and bipolar cells. Results presented in this study show for the first time that down-regulation of DREAM promotes the degeneration of RGCs, amacrine cells, and

  12. Laenderyggens degeneration og radiologi

    DEFF Research Database (Denmark)

    Jacobsen, Steffen; Gosvig, Kasper Kjaerulf; Sonne-Holm, Stig

    2006-01-01

    Low back pain (LBP) is one of the most common conditions, and at the same time one of the most complex nosological entities. The lifetime prevalence is approximately 80%, and radiological features of lumbar degeneration are almost universal in adults. The individual risk factors for LBP and signi......Low back pain (LBP) is one of the most common conditions, and at the same time one of the most complex nosological entities. The lifetime prevalence is approximately 80%, and radiological features of lumbar degeneration are almost universal in adults. The individual risk factors for LBP...... and significant relationships between radiological findings and subjective symptoms have both been notoriously difficult to identify. The lack of consensus on clinical criteria and radiological definitions has hampered the undertaking of properly executed epidemiological studies. The natural history of LBP...

  13. Interleukin-6 Deficiency Attenuates Retinal Ganglion Cell Axonopathy and Glaucoma-Related Vision Loss

    Directory of Open Access Journals (Sweden)

    Franklin D. Echevarria

    2017-05-01

    Full Text Available The pleotropic cytokine interleukin-6 (IL-6 is implicated in retinal ganglion cell (RGC survival and degeneration, including that associated with glaucoma. IL-6 protects RGCs from pressure-induced apoptosis in vitro. However, it is unknown how IL-6 impacts glaucomatous degeneration in vivo. To study how IL-6 influences glaucomatous RGC axonopathy, accompanying glial reactivity, and resultant deficits in visual function, we performed neural tracing, histological, and neurobehavioral assessments in wildtype (B6;129SF2/J; WT and IL-6 knock-out mice (B6;129S2-IL6tm1kopf/J; IL-6-/- after 8 weeks of unilateral or bilateral microbead-induced glaucoma (microbead occlusion model. IOP increased by 20% following microbead injection in both genotypes (p < 0.05. However, deficits in wound healing at the site of corneal injection were noted. In WT mice, elevated IOP produced degenerating axon profiles and decreased axon density in the optic nerve by 15% (p < 0.01. In IL-6-/- mice, axon density in the optic nerve did not differ between microbead- and saline-injected mice (p > 0.05 and degenerating axon profiles were minimal. Preservation of RGC axons was reflected in visual function, where visual acuity decreased significantly in a time-dependent manner with microbead-induced IOP elevation in WT (p < 0.001, but not IL-6-/- mice (p > 0.05. Despite this preservation of RGC axons and visual acuity, both microbead-injected WT and IL-6-/- mice exhibited a 50% decrease in anterograde CTB transport to the superior colliculus, as compared to saline-injected controls (p < 0.01. Assessment of glial reactivity revealed no genotype- or IOP-dependent changes in retinal astrocytes. IOP elevation decreased microglia density and percent retinal area covered in WT mice (p < 0.05, while IL-6-/- mice exhibited only a decrease in density (p < 0.05. Together, our findings indicate that two defining features of RGC axonopathy—axon transport deficits and structural degeneration of

  14. Multicompartment retinal ganglion cells response to high frequency bi-phasic pulse train stimulation: Simulation results.

    Science.gov (United States)

    Maturana, Matias I; Grayden, David B; Burkitt, Anthony N; Meffin, Hamish; Kameneva, Tatiana

    2013-01-01

    Retinal ganglion cells (RGCs) are the sole output neurons of the retina that carry information about a visual scene to the brain. By stimulating RGCs with electrical stimulation, it is possible to elicit a sensation of light for people with macular degeneration or retinitis pigmentosa. To investigate the responses of RGCs to high frequency bi-phasic pulse train stimulation, we use previously constrained models of multi-compartment OFF RGCs. The morphologies of mouse RGCs are taken from the Chalupa set of the NeuroMorpho database. The cell models are divided into compartments representing the dendrites, soma and axon that vary between the cells. A total of 132 cells are simulated in the NEURON environment. Results show that the cell morphology plays an important role in the response characteristics of the cell to high frequency bi-phasic pulse train stimulation.

  15. Adjacent segment degeneration

    OpenAIRE

    Birjandi, Alireza

    2012-01-01

    Abstract: Adjacent segment disease (ASD) is defined as degeneration that develops at mobile segments above or below a fused spinal segment and usually develops after spinal fusion or other back surgeries. Nearly 5 decades ago, the medical findings related to ASD were usually released in case reports as a relatively unusual complication of lumbar or lumbosacral fusions. Since the initial reports, ASD has been found to occur more often than the earlier predictions for its prospect incidence. It...

  16. Calpain Inhibition Attenuates Apoptosis of Retinal Ganglion Cells in Acute Optic Neuritis

    Science.gov (United States)

    Smith, Amena W.; Das, Arabinda; Guyton, M. Kelly; Ray, Swapan K.; Rohrer, Baerbel

    2011-01-01

    Purpose. Optic neuritis (ON), inflammation of the optic nerve, is strongly associated with the pathogenesis of multiple sclerosis (MS) and is initiated by the attack of autoreactive T cells against self-myelin antigens, resulting in demyelination, degeneration of retinal ganglion cells (RGCs), and cumulative visual impairment. Methods. Experimental autoimmune encephalomyelitis (EAE) was induced in Lewis rats on day 0, and animals received daily intraperitoneal injections of calpain inhibitor (calpeptin) or vehicle from day 1 until killed. Retinal cell death was analyzed by DNA fragmentation, and surviving ganglion cells were quantified after double labeling of retinal tissue with TUNEL and Brn3a. The expression of apoptotic and inflammatory proteins was determined by Western blotting. Results. It was demonstrated that calpain inhibition downregulates expression of proapoptotic proteins and the proinflammatory molecule nuclear factor-kappa B (NF-κB) in the retina of Lewis rats with acute EAE. Immunofluorescent labeling revealed that apoptotic cells in the RGC layer of vehicle-treated EAE animals were Brn3a positive, and a moderate dose of calpeptin dramatically reduced the frequency of apoptotic RGCs. Conclusions. These results suggest that calpain inhibition might be a useful supplement to immunomodulatory therapies such as corticosteroids in ON, due to its neuroprotective effect on RGCs. PMID:21613375

  17. Anterior cruciate ligament ganglion: case report

    Directory of Open Access Journals (Sweden)

    André Pedrinelli

    Full Text Available CONTEXT: A ganglion is a cystic formation close to joints or tendinous sheaths, frequently found in the wrist, foot or knee. Intra-articular ganglia of the knee are rare, and most of them are located in the anterior cruciate ligament. The clinical picture for these ganglia comprises pain and movement restrictions in the knee, causing significant impairment to the patient. Symptoms are non-specific, and anterior cruciate ligament ganglia are usually diagnosed through magnetic resonance imaging or arthroscopy. Not all ganglia diagnosed through magnetic resonance imaging need to undergo surgical treatment: only those that cause clinical signs and symptoms do. Surgical results are considered good or excellent in the vast majority of cases. CASE REPORT: A 29-year-old male presented with pain in the left knee during a marathon race. Physical examination revealed limitation in the maximum range of knee extension and pain in the posterior aspect of the left knee. Radiographs of the left knee were normal, but magnetic resonance imaging revealed a multi-lobed cystic structure adjacent to the anterior cruciate ligament, which resembled a ganglion cyst. The mass was removed through arthroscopy, and pathological examination revealed a synovial cyst. Patient recovery was excellent, and he resumed his usual training routine five months later.

  18. Sciatica and claudication caused by ganglion cyst.

    Science.gov (United States)

    Yang, Guang; Wen, Xiaoyu; Gong, Yubao; Yang, Chen

    2013-12-15

    Case report. We report a rare case that a ganglion cyst compressed the sciatic nerve and caused sciatica and claudication in a 51-year-old male. Sciatica and claudication commonly occurs in spinal stenosis. To our knowledge, only 4 cases have been reported on sciatica resulting from posterior ganglion cyst of hip. A 51-year-old male had a 2-month history of radiating pain on his right leg. He could only walk 20 to 30 m before stopping and standing to rest for 1 to 3 minutes. Interestingly, he was able to walk longer distances (about 200 m) when walking slowly in small steps, without any rest. He had been treated as a case of lumbar disc herniation, but conservative treatment was ineffective. On buttock examination, a round, hard, and fixative mass was palpated at the exit of the sciatic nerve. MR imaging of hip revealed a multilocular cystic mass located on the posterior aspect of the superior gemellus and obturator internus, compressing the sciatic nerve. On operation, we found that the cyst extended to the superior gemellus and the obturator internus, positioned right at the outlet of the sciatic nerve. At 18 months of follow-up, the patient continued to be symptom free. He returned to comprehensive physical activity with no limitations. For an extraspinal source, a direct compression on the sciatic nerve also resulted in sciatica and claudication. A meticulous physical examination is very important for the differential diagnosis of extraspinal sciatica from spinal sciatica.

  19. Intravitreal NGF administration counteracts retina degeneration after permanent carotid artery occlusion in rat

    Directory of Open Access Journals (Sweden)

    De Sordi Nadia

    2009-05-01

    Full Text Available Abstract Background The neurotrophin nerve growth factor (NGF is produced by different cell types in the anterior and posterior eye, exerting a neuroprotective role in the adult life. The visual system is highly sensitive to NGF and the retina and optic nerve provides suitable subjects for the study of central nervous system degeneration. The model of bilateral carotid occlusion (two-vessel occlusion, 2VO is a well-established model for chronic brain hypoperfusion leading to brain capillary pathology, to retina and optic nerve degeneration. In order to study if a single intravitreal injection of NGF protects the retina and the optic nerve from degeneration during systemic circulatory diseases, we investigated morphological and molecular changes occurring in the retina and optic nerve of adult rats at different time-points (8, 30 and 75 days after bilateral carotid occlusion. Results We demonstrated that a single intravitreal injection of NGF (5 μg/3 μl performed 24 hours after 2VO ligation has a long-lasting protective effect on retina and optic nerve degeneration. NGF counteracts retinal ganglion cells degeneration by early affecting Bax/Bcl-2 balance- and c-jun- expression (at 8 days after 2VO. A single intravitreal NGF injection regulates the demyelination/remyelination balance after ischemic injury in the optic nerve toward remyelination (at 75 days after 2VO, as indicated by the MBP expression regulation, thus preventing optic nerve atrophy and ganglion cells degeneration. At 8 days, NGF does not modify 2VO-induced alteration in VEFG and related receptors mRNA expression. Conclusion The protective effect of exogenous NGF during this systemic circulatory disease seems to occur also by strengthening the effect of endogenous NGF, the synthesis of which is increased by vascular defect and also by the mechanical lesion associated with NGF or even vehicle intraocular delivery.

  20. Naturalness of nearly degenerate neutrinos

    CERN Document Server

    Casas, J A; Ibarra, Alejandro; Navarro, I

    1999-01-01

    If neutrinos are to play a relevant cosmological role, they must be essentially degenerate. We study whether radiative corrections can or cannot be responsible for the small mass splittings, in agreement with all the available experimental data. We perform an exhaustive exploration of the bimaximal mixing scenario, finding that (i) the vacuum oscillations solution to the solar neutrino problem is always excluded; (ii) if the mass matrix is produced by a see-saw mechanism, there are large regions of the parameter space consistent with the large angle MSW solution, providing a natural origin for the Delta m^2_{sol} << Delta m^2_{atm} hierarchy; (iii) the bimaximal structure becomes then stable under radiative corrections. We also provide analytical expressions for the mass splittings and mixing angles and present a particularly simple see-saw ansatz consistent with all the observations.

  1. Synaptopathy in the noise-exposed and aging cochlea: Primary neural degeneration in acquired sensorineural hearing loss.

    Science.gov (United States)

    Kujawa, Sharon G; Liberman, M Charles

    2015-12-01

    The classic view of sensorineural hearing loss (SNHL) is that the "primary" targets are hair cells, and that cochlear-nerve loss is "secondary" to hair cell degeneration. Our recent work in mouse and guinea pig has challenged that view. In noise-induced hearing loss, exposures causing only reversible threshold shifts (and no hair cell loss) nevertheless cause permanent loss of >50% of cochlear-nerve/hair-cell synapses. Similarly, in age-related hearing loss, degeneration of cochlear synapses precedes both hair cell loss and threshold elevation. This primary neural degeneration has remained hidden for three reasons: 1) the spiral ganglion cells, the cochlear neural elements commonly assessed in studies of SNHL, survive for years despite loss of synaptic connection with hair cells, 2) the synaptic terminals of cochlear nerve fibers are unmyelinated and difficult to see in the light microscope, and 3) the degeneration is selective for cochlear-nerve fibers with high thresholds. Although not required for threshold detection in quiet (e.g. threshold audiometry or auditory brainstem response threshold), these high-threshold fibers are critical for hearing in noisy environments. Our research suggests that 1) primary neural degeneration is an important contributor to the perceptual handicap in SNHL, and 2) in cases where the hair cells survive, neurotrophin therapies can elicit neurite outgrowth from spiral ganglion neurons and re-establishment of their peripheral synapses. This article is part of a Special Issue entitled . Copyright © 2015 Elsevier B.V. All rights reserved.

  2. Laenderyggens degeneration og radiologi

    DEFF Research Database (Denmark)

    Jacobsen, Steffen; Gosvig, Kasper Kjaerulf; Sonne-Holm, Stig

    2006-01-01

    and significant relationships between radiological findings and subjective symptoms have both been notoriously difficult to identify. The lack of consensus on clinical criteria and radiological definitions has hampered the undertaking of properly executed epidemiological studies. The natural history of LBP......Low back pain (LBP) is one of the most common conditions, and at the same time one of the most complex nosological entities. The lifetime prevalence is approximately 80%, and radiological features of lumbar degeneration are almost universal in adults. The individual risk factors for LBP...

  3. Morphological patterns in children with ganglion related enteric neuronal abnormalities.

    Science.gov (United States)

    Henna, Nausheen; Nagi, Abdul H; Sheikh, Muhammad A; Shaukat, Mahmood

    2011-01-01

    Hirschsprung's Disease (HD) is a developmental disorder of enteric nervous system characterised by the absence of ganglion cells in submucosal (Meissner's) and myenteric (Aurbach's) plexuses of distal bowel. The purpose of the present study was to observe and report the morphological patterns of ganglion related enteric neuronal abnormalities in children presented with clinical features of (HD) in a Pakistani population. A total of 92 patients with clinical presentation of HD were enrolled between March 2009 and October 2009. Among them, 8 were excluded according to the exclusion criteria. After detailed history and physical examination, paraffin embedded H and E stained sections were prepared from the serial open biopsies from colorectum. The data was analysed using SPSS-17. Frequencies and percentages are given for qualitative variables. Non-parametric Binomial Chi-Square test was applied to observe within group associations and pganglionic whereas 71 (84.5%) showed ganglion related enteric neuronal abnormalities namely isolated hypoganglionosis 9 (12.7%), immaturity of ganglion cells 9 (12.7%), isolated hyperganglionosis (IND Type B) 2 (2.8%) and Hirschsprung's disease 51 (71.8%). Among HD group, 34 (66.7%) belonged to isolated form and 17 (33.3%) showed combined ganglion related abnormalities. Hirschsprung's disease is common in Pakistani population, followed by hypoganglionosis, immaturity of ganglion cells and IND type B. The presence of hypertrophic nerve fibres was significant in HD, hyperganglionosis and hypoganglionosis, whereas, no hypertrophic nerve fibres were appreciated in immaturity of ganglion cell group.

  4. Biophysical Variation within the M1 Type of Ganglion Cell Photoreceptor

    Directory of Open Access Journals (Sweden)

    Alan J. Emanuel

    2017-10-01

    Full Text Available Intrinsically photosensitive retinal ganglion cells of the M1 type encode environmental irradiance for functions that include circadian and pupillary regulation. Their distinct role, morphology, and molecular markers indicate that they are stereotyped circuit elements, but their physiological uniformity has not been investigated in a systematic fashion. We have profiled the biophysical parameters of mouse M1s and found that extreme variation is their hallmark. Most parameters span 1–3 log units, and the full range is evident in M1s that innervate brain regions serving divergent functions. Biophysical profiles differ among cells possessing similar morphology and between neighboring M1s recorded simultaneously. Variation in each parameter is largely independent of that in others, allowing for flexible individualization. Accordingly, a common stimulus drives heterogeneous spike outputs across cells. By contrast, a population of directionally selective retinal ganglion cells appeared physiologically uniform under similar conditions. Thus, M1s lack biophysical constancy and send diverse signals downstream.

  5. Differential calcium signaling mediated by voltage-gated calcium channels in rat retinal ganglion cells and their unmyelinated axons.

    Directory of Open Access Journals (Sweden)

    Allison Sargoy

    Full Text Available Aberrant calcium regulation has been implicated as a causative factor in the degeneration of retinal ganglion cells (RGCs in numerous injury models of optic neuropathy. Since calcium has dual roles in maintaining homeostasis and triggering apoptotic pathways in healthy and injured cells, respectively, investigation of voltage-gated Ca channel (VGCC regulation as a potential strategy to reduce the loss of RGCs is warranted. The accessibility and structure of the retina provide advantages for the investigation of the mechanisms of calcium signalling in both the somata of ganglion cells as well as their unmyelinated axons. The goal of the present study was to determine the distribution of VGCC subtypes in the cell bodies and axons of ganglion cells in the normal retina and to define their contribution to calcium signals in these cellular compartments. We report L-type Ca channel α1C and α1D subunit immunoreactivity in rat RGC somata and axons. The N-type Ca channel α1B subunit was in RGC somata and axons, while the P/Q-type Ca channel α1A subunit was only in the RGC somata. We patch clamped isolated ganglion cells and biophysically identified T-type Ca channels. Calcium imaging studies of RGCs in wholemounted retinas showed that selective Ca channel antagonists reduced depolarization-evoked calcium signals mediated by L-, N-, P/Q- and T-type Ca channels in the cell bodies but only by L-type Ca channels in the axons. This differential contribution of VGCC subtypes to calcium signals in RGC somata and their axons may provide insight into the development of target-specific strategies to spare the loss of RGCs and their axons following injury.

  6. Microvascularization in trigeminal ganglion of the common tree shrew (Tupaia glis).

    Science.gov (United States)

    Kongstaponkit, S; Pradidarcheep, W; Toutip, S; Chunhabundit, P; Somana, R

    1997-01-01

    Since there is only a limited number of studies of the blood supply to the trigeminal ganglion (TG) in mammalian species, the TG from 16 common tree shrews (Tupaia glis) were investigated by light microscope, transmission electron microscope (TEM) and the corrosion cast technique in conjunction with scanning electron microscope (SEM). It was found that the TG contained clusters of neurons in the peripheral region whereas the bundles of nerve fibers were located more centrally. Each ganglionic neuron had a concentric nucleus and was ensheathed by satellite cells. It was noted that blood vessels of a continuous type were predominantly found in the area where the neurons were densely located and were much less frequently observed in the area occupied by nerve fibers. With TEM, the TG was shown to be mainly associated with large neurons containing big nuclei and prominent nucleoli. The blood supply of the TG is derived from the most rostral branch of the pontine artery, from the stapedial artery or sometimes from the supraorbital artery, and from the accessory meningeal artery which is a branch of the maxillary artery passing through the foramen ovale. These arteries give off branches and become capillary networks in the ganglion before draining blood to the peripheral region. The veins at the medial border drained into the cavernous sinus directly or through the inferior hypophyseal vein, while those at the lateral side of the ganglion carried the blood into the pterygoid plexus via an accessory meningeal vein. The veins along the trigeminal nerve root joined the posterior part of the cavernous sinus. These studies establish a unique anatomical distribution of the TG blood supply in the tree shrew and the utility of the cast/SEM technique in discerning detailed features of the blood supply in the nervous system.

  7. The 5-HTTLPR variant in the serotonin transporter gene modifies degeneration of brain regions important for emotion in behavioral variant frontotemporal dementia

    Directory of Open Access Journals (Sweden)

    Jennifer S. Yokoyama

    2015-01-01

    Full Text Available The serotonin transporter length polymorphism (5-HTTLPR short allele (5-HTTLPR-s has been associated with differential susceptibility for anxiety and depression in multiple psychiatric disorders. 5-HTTLPR-s modifies the serotonergic systems that support emotion and behavioral regulation by reducing gene expression, which slows the reuptake of serotonin, and is associated with distinct morphological and functional effects. Serotonergic systems are also shown to be dysfunctional in behavioral variant frontotemporal dementia (bvFTD, a disease characterized by marked socioemotional dysfunction. However, studies of 5-HTTLPR-s effects in bvFTD have been inconsistent. Our objective was to investigate the patterns of gray matter volume by 5-HTTLPR-s genotype in both healthy older controls and bvFTD patients. We performed voxel-based morphometry of 179 cognitively normal older adults and 24 bvFTD cases to determine brain changes associated with dose (0/1/2 of 5-HTTLPR-s allele. 5-HTTLPR-s frequency did not differ between controls and bvFTD. We found a significant interaction effect whereby carrying more 5-HTTLPR-s alleles in bvFTD was associated with smaller volume in left inferior frontal gyrus (T = 4.86, PFWE = 0.03 and larger volume in right temporal lobe (T = 5.01, PFWE = 0.01. These results suggest that the 5-HTTLPR-s allele differentially influences brain morphology in bvFTD. We propose that patients with bvFTD and 5-HTTLPR-s have altered volumes in regions that support socioemotional behavior, which may be a developmental or disease-related compensation for altered serotonergic activity.

  8. Stellate ganglion blockade for analgesia following upper limb surgery.

    LENUS (Irish Health Repository)

    McDonnell, J G

    2012-01-31

    We report the successful use of a stellate ganglion block as part of a multi-modal postoperative analgesic regimen. Four patients scheduled for orthopaedic surgery following upper limb trauma underwent blockade of the stellate ganglion pre-operatively under ultrasound guidance. Patients reported excellent postoperative analgesia, with postoperative VAS pain scores between 0 and 2, and consumption of morphine in the first 24 h ranging from 0 to 14 mg. While these are preliminary findings, and must be confirmed in a clinical trial, they highlight the potential for stellate ganglion blockade to provide analgesia following major upper limb surgery.

  9. Imipramine protects retinal ganglion cells from oxidative stress through the tyrosine kinase receptor B signaling pathway

    Directory of Open Access Journals (Sweden)

    Ming-lei Han

    2016-01-01

    Full Text Available Retinal ganglion cell (RGC degeneration is irreversible in glaucoma and tyrosine kinase receptor B (TrkB-associated signaling pathways have been implicated in the process. In this study, we attempted to examine whether imipramine, a tricyclic antidepressant, may protect hydrogen peroxide (H 2 O 2 -induced RGC degeneration through the activation of the TrkB pathway in RGC-5 cell lines. RGC-5 cell lines were pre-treated with imipramine 30 minutes before exposure to H 2 O 2 . Western blot assay showed that in H 2 O 2 -damaged RGC-5 cells, imipramine activated TrkB pathways through extracellular signal-regulated protein kinase/TrkB phosphorylation. TUNEL staining assay also demonstrated that imipramine ameliorated H 2 O 2 -induced apoptosis in RGC-5 cells. Finally, TrkB-IgG intervention was able to reverse the protective effect of imipramine on H 2 O 2 -induced RGC-5 apoptosis. Imipramine therefore protects RGCs from oxidative stress-induced apoptosis through the TrkB signaling pathway.

  10. Posterior Lattice Degeneration Characterized by Spectral Domain Optical Tomography

    OpenAIRE

    Manjunath, Varsha; Taha, Mohammed; Fujimoto, James G.; Duker, Jay S.

    2011-01-01

    PURPOSE: To utilize high-resolution spectral domain optical coherence tomography (SD-OCT) in the characterization of retinal and vitreal morphological changes overlying posterior lattice degeneration. METHODS: A cross-sectional, retrospective analysis was performed on 13 eyes of 13 nonconsecutive subjects with posterior lattice degeneration seen at the New England Eye Center, Tufts Medical Center between October 2009 and January 2010. SD-OCT images taken through the region of latti...

  11. Degeneration of auditory nerve fibers in guinea pigs with severe sensorineural hearing loss.

    Science.gov (United States)

    Kroon, Steven; Ramekers, Dyan; Smeets, Emma M; Hendriksen, Ferry G J; Klis, Sjaak F L; Versnel, Huib

    2017-03-01

    Damage to and loss of the organ of Corti leads to secondary degeneration of the spiral ganglion cell (SGC) somata of the auditory nerve. Extensively examined in animal models, this degeneration process of SGC somata following deafening is well known. However, degeneration of auditory nerve axons, which conduct auditory information towards the brainstem, and its relation to SGC soma degeneration are largely unknown. The consequences of degeneration of the axons are relevant for cochlear implantation, which is applied to a deafened system but depends on the condition of the auditory nerve. We investigated the time sequence of degeneration of myelinated type I axons in deafened guinea pigs. Auditory nerves in six normal-hearing and twelve deafened animals, two, six and fourteen weeks (for each group four) after deafening were histologically analyzed. We developed a semi-automated method for axon counting, which allowed for a relatively large sample size (20% of the total cross-sectional area of the auditory nerve). We observed a substantial loss of auditory nerve area (29%), reduction in axon number (59%) and decrease in axoplasm area (41%) fourteen weeks after deafening compared to normal-hearing controls. The correlation between axonal degeneration and that of the SGC somata in the same cochleas was high, although axonal structures appeared to persist longer than the somata, suggesting a slower degeneration process. In the first two weeks after induction of deafness, the axonal cross-sectional area decreased but the axon number did not. In conclusion, the data strongly suggest that each surviving SGC possesses an axon. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Second order degenerate elliptic equations

    International Nuclear Information System (INIS)

    Duong Minh Duc.

    1988-08-01

    Using an improved Sobolev inequality we study a class of elliptic operators which is degenerate inside the domain and strongly degenerate near the boundary of the domain. Our results are applicable to the L 2 -boundary value problem and the mixed boundary problem. (author). 18 refs

  13. Intervertebral disc degeneration in dogs

    NARCIS (Netherlands)

    Bergknut, Niklas

    Back pain is common in both dogs and humans, and is often associated with intervertebral disc (IVD) degeneration. The IVDs are essential structures of the spine and degeneration can ultimately result in diseases such as IVD herniation or spinal instability. In order to design new treatments halting

  14. Intervertebral disc degeneration in dogs

    NARCIS (Netherlands)

    Bergknut, N.|info:eu-repo/dai/nl/314418059

    2011-01-01

    Back pain is common in both dogs and humans, and is often associated with intervertebral disc (IVD) degeneration. The IVDs are essential structures of the spine and degeneration can ultimately result in diseases such as IVD herniation or spinal instability. In order to design new treatments halting

  15. CT brain demonstration of basal ganglion calcification in adult HIV ...

    African Journals Online (AJOL)

    brain barrier has been postulated. Calcification of the basal ganglia in encephalopathic HIV/AIDS children has been relatively well documented. Only two adult HIV cases with basal ganglion calcification (BGC) have been reported in the literature.

  16. Ionic channel changes in glaucomatous retinal ganglion cells: multicompartment modeling.

    Science.gov (United States)

    Maturana, Matias I; Turpin, Andrew; McKendrick, Allison M; Kameneva, Tatiana

    2014-01-01

    This research takes a step towards discovering underlying ionic channel changes in the glaucomatous ganglion cells. Glaucoma is characterized by a gradual death of retinal ganglion cells. In this paper, we propose a hypothesis that the ionic channel concentrations change during the progression of glaucoma. We use computer simulation of a multi-compartment morphologically correct model of a mouse retinal ganglion cell to verify our hypothesis. Using published experimental data, we alter the morphology of healthy ganglion cells to replicate glaucomatous cells. Our results suggest that in glaucomatous cell, the sodium channel concentration decreases in the soma by 30% and by 60% in the dendrites, calcium channel concentration decreases by 10% in all compartments, and leak channel concentration increases by 40% in the soma and by 100% in the dendrites.

  17. Evaluation of new approach to ultrasound guided stellate ganglion block

    Directory of Open Access Journals (Sweden)

    Anju Ghai

    2016-01-01

    Conclusion: There is a significant variation in the anatomy of stellate ganglion at the level of C 6 and C 7 . Ultrasound guided lateral approach increases the efficacy of SGB by deposition of drug subfascially with real-time imaging.

  18. Melanopsin retinal ganglion cell loss in Alzheimer's disease

    DEFF Research Database (Denmark)

    La Morgia, Chiara; Ross-Cisneros, Fred N; Koronyo, Yosef

    2015-01-01

    OBJECTIVE: Melanopsin retinal ganglion cells (mRGCs) are photoreceptors driving circadian photoentrainment, and circadian dysfunction characterizes Alzheimer's disease (AD). We investigated mRGCs in AD, hypothesizing their contribution to circadian dysfunction. METHODS: We assessed retinal nerve...

  19. THE MODULATORY ROLE OF TAURINE IN RETINAL GANGLION CELLS

    OpenAIRE

    Jiang, Zheng; Bulley, Simon; Guzzone, Joseph; Ripps, Harris; Shen, Wen

    2013-01-01

    Taurine (2-aminoethylsuphonic acid) is present in nearly all animal tissues, and is the most abundant free amino acid in muscle, heart, CNS and retina. Although it is known to be a major cytoprotectant and essential for normal retinal development, its role in retinal neurotransmission and modulation is not well understood. We investigated the response of taurine in retinal ganglion cells, and its effect on synaptic transmission between ganglion cells and their pre-synaptic neurons. We find th...

  20. Recurrence of a Periosteal Ganglion in the Tibia

    Directory of Open Access Journals (Sweden)

    Ka-Kin Samuel Ling

    2013-12-01

    Full Text Available Periosteal ganglion is a rare type of ganglia most commonly located in the tibia. The clinical outcomes after surgical excision have not been documented in literature. We report a case of a periosteal ganglion in the proximal tibia with repeated recurrences despite surgical excisions. Magnetic resonance imaging (MRI, contrast arthrogram, and arthroscopy may have their values, especially for the detection of intra-articular communication in juxta-articular lesions.

  1. Troxler Fading, Eye Movements, and Retinal Ganglion Cell Properties

    Directory of Open Access Journals (Sweden)

    Romain Bachy

    2014-12-01

    Full Text Available We present four movies demonstrating the effect of flicker and blur on the magnitude and speed of adaptation for foveal and peripheral vision along the three color axes that isolate retinal ganglion cells projecting to magno, parvo, and konio layers of the LGN. The demonstrations support the eye movement hypothesis for Troxler fading for brightness and color, and demonstrate the effects of flicker and blur on adaptation of each class of retinal ganglion cells.

  2. Scene from above: retinal ganglion cell topography and spatial resolving power in the giraffe (Giraffa camelopardalis).

    Science.gov (United States)

    Coimbra, João Paulo; Hart, Nathan S; Collin, Shaun P; Manger, Paul R

    2013-06-15

    The giraffe (Giraffa camelopardalis) is a browser that uses its extensible tongue to selectively collect leaves during foraging. As the tallest extant terrestrial mammal, its elevated head height provides panoramic surveillance of the environment. These aspects of the giraffe's ecology and phenotype suggest that vision is of prime importance. Using Nissl-stained retinal wholemounts and stereological methods, we quantitatively assessed the retinal specializations in the ganglion cell layer of the giraffe. The mean total number of retinal ganglion cells was 1,393,779 and their topographic distribution revealed the presence of a horizontal visual streak and a temporal area. With a mean peak of 14,271 cells/mm(2), upper limits of spatial resolving power in the temporal area ranged from 25 to 27 cycles/degree. We also observed a dorsotemporal extension (anakatabatic area) that tapers toward the nasal retina giving rise to a complete dorsal arch. Using neurofilament-200 immunohistochemistry, we also detected a dorsal arch formed by alpha ganglion cells with density peaks in the temporal (14-15 cells/mm(2)) and dorsonasal (10 cells/mm(2)) regions. As with other artiodactyls, the giraffe shares the presence of a horizontal streak and a temporal area which, respectively, improve resolution along the horizon and in the frontal visual field. The dorsal arch is related to the giraffe's head height and affords enhanced resolution in the inferior visual field. The alpha ganglion cell distribution pattern is unique to the giraffe and enhances acquisition of motion information for the control of tongue movement during foraging and the detection of predators. Copyright © 2012 Wiley Periodicals, Inc.

  3. The modulatory role of taurine in retinal ganglion cells.

    Science.gov (United States)

    Jiang, Zheng; Bulley, Simon; Guzzone, Joseph; Ripps, Harris; Shen, Wen

    2013-01-01

    Taurine (2-aminoethylsuphonic acid) is present in nearly all animal tissues, and is the most abundant free amino acid in muscle, heart, CNS, and retina. Although it is known to be a major cytoprotectant and essential for normal retinal development, its role in retinal neurotransmission and modulation is not well understood. We investigated the response of taurine in retinal ganglion cells, and its effect on synaptic transmission between ganglion cells and their presynaptic neurons. We find that taurine-elicited currents in ganglion cells could be fully blocked by both strychnine and SR95531, glycine and GABA(A) receptor antagonists, respectively. This suggests that taurine-activated receptors might share the antagonists with GABA and glycine receptors. The effect of taurine at micromolar concentrations can effectively suppress spontaneous vesicle release from the presynaptic neurons, but had limited effects on light-evoked synaptic signals in ganglion cells. We also describe a metabotropic effect of taurine in the suppression of light-evoked response in ganglion cells. Clearly, taurine acts in multiple ways to modulate synaptic signals in retinal output neurons, ganglion cells.

  4. Topography of ganglion cell production in the cat's retina

    International Nuclear Information System (INIS)

    Walsh, C.; Polley, E.H.

    1985-01-01

    The ganglion cells of the cat's retina form several classes distinguishable in terms of soma size, axon diameter, dendritic morphology, physiological properties, and central connections. Labeling with [ 3 H]thymidine shows that the ganglion cells which survive in the adult are produced as several temporally shifted, overlapping waves: medium-sized cells are produced before large cells, whereas the smallest ganglion cells are produced throughout the period of ganglion cell generation. Large cells and medium-sized cells show the same distinctive pattern of production, forming rough spirals around the area centralis. The oldest cells tend to lie superior and nasal to the area centralis, whereas cells in the inferior nasal retina and inferior temporal retina are, in general, progressively younger. Within each retinal quadrant, cells nearer the area centralis tend to be older than cells in the periphery, but there is substantial overlap. The retinal raphe divides the superior temporal quadrant into two zones with different patterns of cell addition. Superior temporal retina near the vertical meridian adds cells only slightly later than superior nasal retina, whereas superior temporal retina near the horizontal meridian adds cells very late, contemporaneously with inferior temporal retina. The broader wave of production of smaller ganglion cells seems to follow this same spiral pattern at its beginning and end. The presence of the area centralis as a nodal point about which ganglion cell production in the retinal quadrants pivots suggests that the area centralis is already an important retinal landmark even at the earliest stages of retinal development

  5. THE MODULATORY ROLE OF TAURINE IN RETINAL GANGLION CELLS

    Science.gov (United States)

    Jiang, Zheng; Bulley, Simon; Guzzone, Joseph; Ripps, Harris; Shen, Wen

    2017-01-01

    Taurine (2-aminoethylsuphonic acid) is present in nearly all animal tissues, and is the most abundant free amino acid in muscle, heart, CNS and retina. Although it is known to be a major cytoprotectant and essential for normal retinal development, its role in retinal neurotransmission and modulation is not well understood. We investigated the response of taurine in retinal ganglion cells, and its effect on synaptic transmission between ganglion cells and their pre-synaptic neurons. We find that taurine-elicited currents in ganglion cells could be fully blocked by both strychnine and SR95531, glycine and GABAA receptor antagonists, respectively. This suggests that taurine-activated receptors might share the antagonists with GABA and glycine receptors. The effect of taurine at micromolar concentrations can effectively suppress spontaneous vesicle release from the pre-synaptic neurons, but had limited effects on light-evoked synaptic signals in ganglion cells. We also describe a metabotropic effect of taurine in the suppression of light-evoked response in ganglion cells. Clearly, taurine acts in multiple ways to modulate synaptic signals in retinal output neurons, ganglion cells. PMID:23392924

  6. Stimulation of nicotinamide adenine dinucleotide biosynthetic pathways delays axonal degeneration after axotomy.

    Science.gov (United States)

    Sasaki, Yo; Araki, Toshiyuki; Milbrandt, Jeffrey

    2006-08-16

    Axonal degeneration occurs in many neurodegenerative diseases and after traumatic injury and is a self-destructive program independent from programmed cell death. Previous studies demonstrated that overexpression of nicotinamide mononucleotide adenylyltransferase 1 (Nmnat1) or exogenous application of nicotinamide adenine dinucleotide (NAD) can protect axons of cultured dorsal root ganglion (DRG) neurons from degeneration caused by mechanical or neurotoxic injury. In mammalian cells, NAD can be synthesized from multiple precursors, including tryptophan, nicotinic acid, nicotinamide, and nicotinamide riboside (NmR), via multiple enzymatic steps. To determine whether other components of these NAD biosynthetic pathways are capable of delaying axonal degeneration, we overexpressed each of the enzymes involved in each pathway and/or exogenously administered their respective substrates in DRG cultures and assessed their capacity to protect axons after axotomy. Among the enzymes tested, Nmnat1 had the strongest protective effects, whereas nicotinamide phosphoribosyl transferase and nicotinic acid phosphoribosyl transferase showed moderate protective activity in the presence of their substrates. Strong axonal protection was also provided by Nmnat3, which is predominantly located in mitochondria, and an Nmnat1 mutant localized to the cytoplasm, indicating that the subcellular location of NAD production is not crucial for protective activity. In addition, we showed that exogenous application of the NAD precursors that are the substrates of these enzymes, including nicotinic acid mononucleotide, nicotinamide mononucleotide, and NmR, can also delay axonal degeneration. These results indicate that stimulation of NAD biosynthetic pathways via a variety of interventions may be useful in preventing or delaying axonal degeneration.

  7. Stimulation of autophagy prevents amyloid-β peptide-induced neuritic degeneration in PC12 cells.

    Science.gov (United States)

    Yang, Yi; Chen, Sicong; Zhang, Jiafeng; Li, Chentan; Sun, Yonghong; Zhang, Lihui; Zheng, Xiaoxiang

    2014-01-01

    Autophagy is a lysosomal degradative process essential for neuronal homeostasis, whereas autophagic failure has been linked to accumulating neurodegenerative disorders. However, the precise role of autophagy in axonal and dendritic degeneration in Alzheimer's disease (AD) remains unclear. In this study, we aim to investigate the precise effect of autophagy in amyloid-β peptide (Aβ)25-35-mediated neurite degeneration. Aβ35-25, the non-neurotoxic reverse sequence analogue of Aβ25-35, was used as a negative control. Our results showed that Aβ25-35 dose-dependently suppressed PC12 proliferation and induced autophagy induction in neurites (axons and dendrites). A high proportion of autophagic structures in PC12 neurites were autolysosomes after 24 h of Aβ25-35 treatment. Autophagy inhibition by 3-methyladenine (3MA), LY294002, and chloroquine (CQ) could not relieve the Aβ25-35-induced neurite degeneration, while administration of autophagy stimulator rapamycin or AR-12 efficiently suppressed neurite degeneration. Autophagosomes colocalized with fragmented mitochondria after Aβ25-35 treatment. Similar results were obtained using in vitro cultured superior cervical ganglion neurons. These findings demonstrate that autophagy stimulation may prevent neuritic degeneration following Aβ25-35 treatment. Upregulation of autophagic activity may provide a valuable approach for the treatment of axonal and dendritic dystrophy in AD patients.

  8. Lycium barbarum (wolfberry reduces secondary degeneration and oxidative stress, and inhibits JNK pathway in retina after partial optic nerve transection.

    Directory of Open Access Journals (Sweden)

    Hongying Li

    Full Text Available Our group has shown that the polysaccharides extracted from Lycium barbarum (LBP are neuroprotective for retinal ganglion cells (RGCs in different animal models. Protecting RGCs from secondary degeneration is a promising direction for therapy in glaucoma management. The complete optic nerve transection (CONT model can be used to study primary degeneration of RGCs, while the partial optic nerve transection (PONT model can be used to study secondary degeneration of RGCs because primary degeneration of RGCs and secondary degeneration can be separated in location in the same retina in this model; in other situations, these types of degeneration can be difficult to distinguish. In order to examine which kind of degeneration LBP could delay, both CONT and PONT models were used in this study. Rats were fed with LBP or vehicle daily from 7 days before surgery until sacrifice at different time-points and the surviving numbers of RGCs were evaluated. The expression of several proteins related to inflammation, oxidative stress, and the c-jun N-terminal kinase (JNK pathways were detected with Western-blot analysis. LBP did not delay primary degeneration of RGCs after either CONT or PONT, but it did delay secondary degeneration of RGCs after PONT. We found that LBP appeared to exert these protective effects by inhibiting oxidative stress and the JNK/c-jun pathway and by transiently increasing production of insulin-like growth factor-1 (IGF-1. This study suggests that LBP can delay secondary degeneration of RGCs and this effect may be linked to inhibition of oxidative stress and the JNK/c-jun pathway in the retina.

  9. Polymodal Sensory Integration in Retinal Ganglion Cells.

    Science.gov (United States)

    Križaj, David

    2016-01-01

    An animal's ability to perceive the external world is conditioned by its capacity to extract and encode specific features of the visual image. The output of the vertebrate retina is not a simple representation of the 2D visual map generated by photon absorptions in the photoreceptor layer. Rather, spatial, temporal, direction selectivity and color "dimensions" of the original image are distributed in the form of parallel output channels mediated by distinct retinal ganglion cell (RGC) populations. We propose that visual information transmitted to the brain includes additional, light-independent, inputs that reflect the functional states of the retina, anterior eye and the body. These may include the local ion microenvironment, glial metabolism and systemic parameters such as intraocular pressure, temperature and immune activation which act on ion channels that are intrinsic to RGCs. We particularly focus on light-independent mechanical inputs that are associated with physical impact, cell swelling and intraocular pressure as excessive mechanical stimuli lead to the counterintuitive experience of "pressure phosphenes" and/or debilitating blinding disease such as glaucoma and diabetic retinopathy. We point at recently discovered retinal mechanosensitive ion channels as examples through which molecular physiology brings together Greek phenomenology, modern neuroscience and medicine. Thus, RGC output represents a unified picture of the embodied context within which vision takes place.

  10. [Lattice degeneration of the retina].

    Science.gov (United States)

    Boĭko, E V; Suetov, A A; Mal'tsev, D S

    2014-01-01

    Lattice degeneration of the retina is a clinically important type of peripheral retinal dystrophies due to its participation in the pathogenesis of rhegmatogenous retinal detachment. In spite of extensive epidemiological, morphological, and clinical data, the question on causes of this particular type of retinal dystrophies currently remains debatable. Existing hypotheses on pathogenesis of retinal structural changes in lattice degeneration explain it to a certain extent. In clinical ophthalmology it is necessary to pay close attention to this kind of degenerations and distinguish between cases requiring preventive treatment and those requiring monitoring.

  11. Degenerate asymptotic perturbation theory

    International Nuclear Information System (INIS)

    Hunziker, W.; Pillet, C.A.

    1983-01-01

    Asymptotic Rayleigh-Schroedinger perturbation theory for discrete eigenvalues is developed systematically in the general degenerate case. For this purpose we study the spectral properties of mxm - matrix functions A(kappa) of a complex variable kappa which have an asymptotic expansion ΣAsub(k)kappasup(k) as kappa->0. We show that asymptotic expansions for groups of eigenvalues and for the corresponding spectral projections of A(kappa) can be obtained from the set [Asub(k)] by analytic perturbation theory. Special attention is given to the case where A(kappa) is Borel-summable in some sector originating from kappa=0 with opening angle >π. Here we prove that the asymptotic series describe individual eigenvalues and eigenprojections of A(kappa) which are shown to be holomorphic in S near kappa=0 and Borel summable if Asub(k)sup(*)=Asub(k) for all k. We then fit these results into the scheme of Rayleigh-Schroedinger perturbation theory and we give some examples of asymptotic estimates for Schroedinger operators. (orig.)

  12. Temporal response properties of retinal ganglion cells in rd1 mice evoked by amplitude-modulated electrical pulse trains.

    Science.gov (United States)

    Ryu, Sang Baek; Ye, Jang Hee; Goo, Yong Sook; Kim, Chi Hyun; Kim, Kyung Hwan

    2010-12-01

    The electrophysiological properties of degenerated retinas responding to amplitude-modulated electrical pulse trains were investigated to provide a guideline for the development of a stimulation strategy for retinal prostheses. The activities of retinal ganglion cells (RGCs) in response to amplitude-modulated pulse trains were recorded from an in vitro model of retinal prosthesis, which consisted of an rd1 mouse retinal patch attached to a planar multielectrode array. The ability of the population activities of RGCs to effectively represent, or encode, the information on the visual intensity time series, when the intensity of visual input is transformed to pulse amplitudes, was investigated. An optimal pulse amplitude range was selected so that RGC firing rates increased monotonically and linearly. An approximately 10-Hz rhythm was observed in the field potentials from degenerated retinas, which resulted in a rhythmic burst of spontaneous spikes. Multiple peaks were present in poststimulus time histograms, with interpeak intervals corresponding to the oscillation frequency of the field potentials. Phase resetting of the field potential oscillation by stimulation was consistently observed. Despite a prominent alteration of the properties of electrically evoked firing with respect to normal retinas, RGC response strengths could be modulated by pulse amplitude. Accordingly, the temporal information of stimulation could be faithfully represented in the RGC firing patterns by an amplitude-modulated pulse train. The results suggest that pulse amplitude modulation is a feasible means of implementing a stimulation strategy for retinal prostheses, despite the marked change in the physiological properties of RGCs in degenerated retinas.

  13. Lateral geniculate atrophy in Parkinson's with visual hallucination: A trans-synaptic degeneration?

    Science.gov (United States)

    Lee, Jee-Young; Yoon, Eun Jin; Lee, Woong Woo; Kim, Yu Kyeong; Lee, Jun-Young; Jeon, Beomseok

    2016-04-01

    Defective visual information processing contributes to visual hallucination in PD, for which "top-down" and "bottom-up" impairment are suggested mechanisms. This study was aimed to investigate macro- and microstructural neural changes in afferent visual pathways in relation to visual hallucination in nondemented PD patients. This study included 24 nondemented, nondepressed PD patients (10 hallucinating and 14 nonhallucinating) and 15 age-matched healthy controls. We analyzed volumetric and diffusion tensor MRI data by applying region of interest analyses on the visual pathways, including the optic chiasm, bilateral optic nerves, lateral geniculate bodies, optic radiations, and primary visual cortex. Patients' demographic characteristics, daily medication doses, as well as duration and motor severity of PD were similar in the two PD groups. Compared to PD patients without hallucination, those with hallucination had fractional anisotropy decrease in the left optic nerve and showed atrophy of lateral geniculate bodies, especially in the left side. In addition, the PD with hallucination group had diffusivity increase in the left optic radiation compared to that in the PD without hallucination and healthy control groups. There were no differences in the primary visual cortex volume among the study groups. We found microstructural alterations in visual pathways in nondemented PD patients with hallucination, mainly in first-order neurons and atrophy in the lateral geniculate body where the retinal ganglion cells synapse to second-order neurons. Afferent visual pathway degeneration may occur in a trans-synaptic way in PD. Further studies warrant to be conducted. © 2016 International Parkinson and Movement Disorder Society.

  14. Endothelin B receptors contribute to retinal ganglion cell loss in a rat model of glaucoma.

    Directory of Open Access Journals (Sweden)

    Alena Z Minton

    Full Text Available Glaucoma is an optic neuropathy, commonly associated with elevated intraocular pressure (IOP characterized by optic nerve degeneration, cupping of the optic disc, and loss of retinal ganglion cells which could lead to loss of vision. Endothelin-1 (ET-1 is a 21-amino acid vasoactive peptide that plays a key role in the pathogenesis of glaucoma; however, the receptors mediating these effects have not been defined. In the current study, endothelin B (ET(B receptor expression was assessed in vivo, in the Morrison's ocular hypertension model of glaucoma in rats. Elevation of IOP in Brown Norway rats produced increased expression of ET(B receptors in the retina, mainly in retinal ganglion cells (RGCs, nerve fiber layer (NFL, and also in the inner plexiform layer (IPL and inner nuclear layer (INL. To determine the role of ET(B receptors in neurodegeneration, Wistar-Kyoto wild type (WT and ET(B receptor-deficient (KO rats were subjected to retrograde labeling with Fluoro-Gold (FG, following which IOP was elevated in one eye while the contralateral eye served as control. IOP elevation for 4 weeks in WT rats caused an appreciable loss of RGCs, which was significantly attenuated in KO rats. In addition, degenerative changes in the optic nerve were greatly reduced in KO rats compared to those in WT rats. Taken together, elevated intraocular pressure mediated increase in ET(B receptor expression and its activation may contribute to a decrease in RGC survival as seen in glaucoma. These findings raise the possibility of using endothelin receptor antagonists as neuroprotective agents for the treatment of glaucoma.

  15. Computed tomography of Wallerian degeneration

    International Nuclear Information System (INIS)

    Uchino, Akira; Maeda, Fumihiko

    1986-01-01

    CT findings of wallerian degeneration of the pyramidal tract at the midbrain (atrophy of cerebral peduncle following cerebrovascular accident) were studied in 34 patients (44 CT scans) with old cerebrovascular accidents. Severe atrophy of cerebral peduncle was noted when the ipsilateral motor cortex was involved. However, when the posterior limb of the internal capsule was involved, atrophy of the ipsilateral cerebral peduncle was mild. In this series, the shortest interval between cerebrovascular accident and wallerian degeneration was 8 month. (author)

  16. Frequency Responses of Rat Retinal Ganglion Cells.

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    Alex E Hadjinicolaou

    Full Text Available There are 15-20 different types of retinal ganglion cells (RGC in the mammalian retina, each encoding different aspects of the visual scene. The mechanism by which post-synaptic signals from the retinal network generate spikes is determined by each cell's intrinsic electrical properties. Here we investigate the frequency responses of morphologically identified rat RGCs using intracellular injection of sinusoidal current waveforms, to assess their intrinsic capabilities with minimal contributions from the retinal network. Recorded cells were classified according to their morphological characteristics (A, B, C or D-type and their stratification (inner (i, outer (o or bistratified in the inner plexiform layer (IPL. Most cell types had low- or band-pass frequency responses. A2, C1 and C4o cells were band-pass with peaks of 15-30 Hz and low-pass cutoffs above 56 Hz (A2 cells and ~42 Hz (C1 and C4o cells. A1 and C2i/o cells were low-pass with peaks of 10-15 Hz (cutoffs 19-25 Hz. Bistratified D1 and D2 cells were also low-pass with peaks of 5-10 Hz (cutoffs ~16 Hz. The least responsive cells were the B2 and C3 types (peaks: 2-5 Hz, cutoffs: 8-11 Hz. We found no difference between cells stratifying in the inner and outer IPL (i.e., ON and OFF cells or between cells with large and small somas or dendritic fields. Intrinsic physiological properties (input resistance, spike width and sag had little impact on frequency response at low frequencies, but account for 30-40% of response variability at frequencies >30 Hz.

  17. Senso-Neuroendocrine Cells Within The Cerebral Ganglion Of The Earthworm Aporrectodea Caliginosa

    OpenAIRE

    Al Yousuf, Shoa'a [شعاع السيد اليوسف

    1992-01-01

    Ciliated neurones of probable endocrine function are present inside and outside the cerebral ganglion of the earthworm Aporrectodea caliginosa. Cell fibers contain clusters ofsynaptoid vesicles in regions adjacent to the brain capsule or muscles. The cell bodies also send axons to terminate within the neuropile, where synapses and exocytosis of their secretory granules occur. Cytochemical studies indicate the presence of catecholamines within these granules. باستخدام المجهر الالكتروني النف...

  18. Paranode Abnormalities and Oxidative Stress in Optic Nerve Vulnerable to Secondary Degeneration: Modulation by 670 nm Light Treatment.

    Directory of Open Access Journals (Sweden)

    Charis R Szymanski

    Full Text Available Secondary degeneration of nerve tissue adjacent to a traumatic injury results in further loss of neurons, glia and function, via mechanisms that may involve oxidative stress. However, changes in indicators of oxidative stress have not yet been demonstrated in oligodendrocytes vulnerable to secondary degeneration in vivo. We show increases in the oxidative stress indicator carboxymethyl lysine at days 1 and 3 after injury in oligodendrocytes vulnerable to secondary degeneration. Dihydroethidium staining for superoxide is reduced, indicating endogenous control of this particular reactive species after injury. Concurrently, node of Ranvier/paranode complexes are altered, with significant lengthening of the paranodal gap and paranode as well as paranode disorganisation. Therapeutic administration of 670 nm light is thought to improve oxidative metabolism via mechanisms that may include increased activity of cytochrome c oxidase. Here, we show that light at 670 nm, delivered for 30 minutes per day, results in in vivo increases in cytochrome c oxidase activity co-localised with oligodendrocytes. Short term (1 day 670 nm light treatment is associated with reductions in reactive species at the injury site. In optic nerve vulnerable to secondary degeneration superoxide in oligodendrocytes is reduced relative to handling controls, and is associated with reduced paranode abnormalities. Long term (3 month administration of 670 nm light preserves retinal ganglion cells vulnerable to secondary degeneration and maintains visual function, as assessed by the optokinetic nystagmus visual reflex. Light at a wavelength of 670 nm may serve as a therapeutic intervention for treatment of secondary degeneration following neurotrauma.

  19. Posterior lattice degeneration characterized by spectral domain optical coherence tomography.

    Science.gov (United States)

    Manjunath, Varsha; Taha, Mohammed; Fujimoto, James G; Duker, Jay S

    2011-03-01

    The purpose of this study was to use high-resolution spectral domain optical coherence tomography in the characterization of retinal and vitreal morphological changes overlying posterior lattice degeneration. A cross-sectional retrospective analysis was performed on 13 eyes of 13 nonconsecutive subjects with posterior lattice degeneration seen at the New England Eye Center, Tufts Medical Center between October 2009 and January 2010. Spectral domain optical coherence tomography images taken through the region of lattice degeneration were qualitatively analyzed. Four characteristic changes of the retina and vitreous were seen in the 13 eyes with lattice degeneration: 1) anterior/posterior U-shaped vitreous traction; 2) retinal breaks; 3) focal retinal thinning; and 4) vitreous membrane formation. The morphologic appearance of vitreous traction and retinal breaks were found to be consistent with previous histologic reports. It is possible to image posterior lattice degeneration in many eyes using spectral domain optical coherence tomography and to visualize the spectrum of retinal and vitreous changes throughout the area of lattice degeneration.

  20. A model for the receptive field of retinal ganglion cells.

    Science.gov (United States)

    Cho, Myoung Won; Choi, M Y

    2014-01-01

    Most retina ganglion cells have center-surround receptive fields, where the center may be either ON or OFF while the surround is the opposite. We clarify the functional roles of the receptive field structure, on the basis of the modern theory of natural data processing. It is suggested that the retina shares the principal mechanism and performance of image processing with a video codec in computers, where the antagonism in spatial or temporal receptive fields originates from the orthogonality condition between linear filters for optimal coding of visual signals. We also reveal what visual information is multiplexed across the discharges of an ensemble of ganglion cells. Our theory makes it possible to predict the cross-correlations between ganglion cell spikes, which are optimized for LGN cells to respond accurately and quickly to their receptive fields. Copyright © 2013 Elsevier Ltd. All rights reserved.

  1. Valproic acid prevents NMDA-induced retinal ganglion cell death via stimulation of neuronal TrkB receptor signaling.

    Science.gov (United States)

    Kimura, Atsuko; Namekata, Kazuhiko; Guo, Xiaoli; Noro, Takahiko; Harada, Chikako; Harada, Takayuki

    2015-03-01

    Valproic acid (VPA) is widely prescribed for treatment of epilepsy, mood disorders, migraines, and neuropathic pain. It exerts its therapeutic benefits through multiple mechanisms, including enhancement of GABAergic activity, activation of prosurvival protein kinases, and inhibition of histone deacetylase. Increasing evidence suggests that VPA possesses neuroprotective properties. We examined neuroprotective effects of VPA in an N-methyl-d-aspartate (NMDA) excitotoxicity model, which mimics some of the pathological features of glaucoma. In vivo retinal imaging using optical coherence tomography revealed that NMDA-induced retinal degeneration was suppressed in the VPA-treated retina, and histological analyses confirmed that VPA reduced retinal ganglion cell death. In vivo electrophysiological analyses demonstrated that visual impairment was prevented in the VPA-treated retina, clearly establishing both histological and functional effects of VPA. Brain-derived neurotrophic factor (BDNF) expression was up-regulated in Müller glial cells, and neuroprotective effects of VPA on retinal ganglion cells were significantly reduced in a conditional knockout mouse strain with deletion of tropomyosin receptor kinase B (TrkB), a receptor for BDNF from retinal ganglion cells. The results show that VPA stimulates BDNF up-regulation in Müller glial cells and provides direct evidence that neuronal TrkB is important in VPA-mediated neuroprotection. Also, VPA suppresses oxidative stress induced by NMDA in the retina. Our findings raise intriguing possibilities that the widely prescribed drug VPA may be useful for treatment of glaucoma. Copyright © 2015 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

  2. Comparative study of photoreceptor and retinal ganglion cell topography and spatial resolving power in Dipsadidae snakes.

    Science.gov (United States)

    Hauzman, Einat; Bonci, Daniela M O; Grotzner, Sonia R; Mela, Maritana; Liber, André M P; Martins, Sonia L; Ventura, Dora F

    2014-01-01

    The diurnal Dipsadidae snakes Philodryas olfersii and P. patagoniensis are closely related in their phylogeny but inhabit different ecological niches. P. olfersii is arboreal, whereas P. patagoniensis is preferentially terrestrial. The goal of the present study was to compare the density and topography of neurons, photoreceptors, and cells in the ganglion cell layer in the retinas of these two species using immunohistochemistry and Nissl staining procedures and estimate the spatial resolving power of their eyes based on the ganglion cell peak density. Four morphologically distinct types of cones were observed by scanning electron microscopy, 3 of which were labeled with anti-opsin antibodies: large single cones and double cones labeled by the antibody JH492 and small single cones labeled by the antibody JH455. The average densities of photoreceptors and neurons in the ganglion cell layer were similar in both species (∼10,000 and 7,000 cells·mm(-2), respectively). The estimated spatial resolving power was also similar, ranging from 2.4 to 2.7 cycles·degree(-1). However, the distribution of neurons had different specializations. In the arboreal P. olfersii, the isodensity maps had a horizontal visual streak, with a peak density in the central region and a lower density in the dorsal retina. This organization might be relevant for locomotion and hunting behavior in the arboreal layer. In the terrestrial P. patagoniensis, a concentric pattern of decreasing cell density emanated from an area centralis located in the naso-ventral retina. Lower densities were observed in the dorsal region. The ventrally high density improves the resolution in the superior visual field and may be an important adaptation for terrestrial snakes to perceive the approach of predators from above. © 2014 S. Karger AG, Basel.

  3. Effect of Extracellular Zinc Chelator on Rat Retinal Ganglion Cell Number, and Taurine and Zinc Transporters in These Cells

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    Asarí Márquez García

    2017-05-01

    Full Text Available Zinc deficiency in humans causes decreased antioxidants in the retina and is related with abnormal darkness adaptation, cataracts, blindness, and macular degeneration. There is little information about the effects of zinc on the taurine system in mammalian retinal cells. Therefore, we studied the effect of zinc on the taurine transporter (TAUT and zinc transporters (ZnT-1 and 3 using the extracellular zinc chelator, diethylenetriaminepentaacetic acid (DTPA by fluorescence immunocytochemistry and immunohistochemistry in the ganglion cells (CG and cell layers of the retina of rats. Three days after administration of DTPA (10µM primary antibodies and secondary antibodies conjugated with rhodamine or fluorescein isothiocyanate (FITC were used as required. For immunocytochemical labeling approximately three hundred cells per condition were counted. For immunohistochemical labeling, the fluorescence intensity was measured as integrated optical density (DOI in four areas for each layer of tissue. DTPA produced a decrease of 32 % and 29 % in GC of the total cells labeled with antibody against glycoprotein Thy 1.1 and γ-synuclein, respectively. It also produced a significant decrease in TAUT localization in 27 and 28 % compared to controls. DTPA produced a decrease in the localization of ZnT-1 and ZnT-3 in the retina layers (ganglion cells, GCC and the outer and inner plexiform, CEP and CIP. The study of these molecules in the retina is relevant to understanding the interactions of taurine and zinc in this structure.

  4. Metabolic anatomy of paraneoplastic cerebellar degeneration

    International Nuclear Information System (INIS)

    Anderson, N.E.; Posner, J.B.; Sidtis, J.J.; Moeller, J.R.; Strother, S.C.; Dhawan, V.; Rottenberg, D.A.

    1988-01-01

    Eleven patients with acquired cerebellar degeneration (10 of whom had paraneoplastic cerebellar degeneration [PCD]) were evaluated using neuropsychological tests and 18 F-fluorodeoxyglucose/positron emission tomography to (1) quantify motor, cognitive, and metabolic abnormalities; (2) determine if characteristic alterations in the regional cerebral metabolic rate for glucose (rCMRGlc) are associated with PCD; and (3) correlate behavioral and metabolic measures of disease severity. Eighteen volunteer subjects served as normal controls. Although some PCD neuropsychological test scores were abnormal, these results could not, in general, be dissociated from the effects of dysarthria and ataxia. rCMRGlc was reduced in patients with PCD (versus normal control subjects) in all regions except the brainstem. Analysis of patient and control rCMRGlc data using a mathematical model of regional metabolic interactions revealed two metabolic pattern descriptors, SSF1 and SSF2, which distinguished patients with PCD from normal control subjects; SSF2, which described a metabolic coupling between cerebellum, cuneus, and posterior temporal, lateral frontal, and paracentral cortex, correlated with quantitative indices of cerebellar dysfunction. Our inability to document substantial intellectual impairment in 7 of 10 patients with PCD contrasts with the 50% incidence of dementia in PCD reported by previous investigators. Widespread reductions in PCD rCMRGlc may result from the loss of cerebellar efferents to thalamus and forebrain structures, a reverse cerebellar diaschisis

  5. Metabolic anatomy of paraneoplastic cerebellar degeneration

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, N.E.; Posner, J.B.; Sidtis, J.J.; Moeller, J.R.; Strother, S.C.; Dhawan, V.; Rottenberg, D.A.

    1988-06-01

    Eleven patients with acquired cerebellar degeneration (10 of whom had paraneoplastic cerebellar degeneration (PCD)) were evaluated using neuropsychological tests and /sup 18/F-fluorodeoxyglucose/positron emission tomography to (1) quantify motor, cognitive, and metabolic abnormalities; (2) determine if characteristic alterations in the regional cerebral metabolic rate for glucose (rCMRGlc) are associated with PCD; and (3) correlate behavioral and metabolic measures of disease severity. Eighteen volunteer subjects served as normal controls. Although some PCD neuropsychological test scores were abnormal, these results could not, in general, be dissociated from the effects of dysarthria and ataxia. rCMRGlc was reduced in patients with PCD (versus normal control subjects) in all regions except the brainstem. Analysis of patient and control rCMRGlc data using a mathematical model of regional metabolic interactions revealed two metabolic pattern descriptors, SSF1 and SSF2, which distinguished patients with PCD from normal control subjects; SSF2, which described a metabolic coupling between cerebellum, cuneus, and posterior temporal, lateral frontal, and paracentral cortex, correlated with quantitative indices of cerebellar dysfunction. Our inability to document substantial intellectual impairment in 7 of 10 patients with PCD contrasts with the 50% incidence of dementia in PCD reported by previous investigators. Widespread reductions in PCD rCMRGlc may result from the loss of cerebellar efferents to thalamus and forebrain structures, a reverse cerebellar diaschisis.

  6. An alternative pathway for signal flow from rod photoreceptors to ganglion cells in mammalian retina.

    OpenAIRE

    DeVries, S H; Baylor, D A

    1995-01-01

    Rod signals in the mammalian retina are thought to reach ganglion cells over the circuit rod-->rod depolarizing bipolar cell-->AII amacrine cell-->cone bipolar cells-->ganglion cells. A possible alternative pathway involves gap junctions linking the rods and cones, the circuit being rod-->cone-->cone bipolar cells-->ganglion cells. It is not clear whether this second pathway indeed relays rod signals to ganglion cells. We studied signal flow in the isolated rabbit retina with a multielectrode...

  7. Dopaminergic modulation of tracer coupling in a ganglion-amacrine cell network

    OpenAIRE

    MILLS, STEPHEN L.; XIA, XIAO-BO; HOSHI, HIDEO; FIRTH, SALLY I.; RICE, MARGARET E.; FRISHMAN, LAURA J.; MARSHAK, DAVID W.

    2007-01-01

    Many retinal ganglion cells are coupled via gap junctions with neighboring amacrine cells and ganglion cells. We investigated the extent and dynamics of coupling in one such network, the OFF α ganglion cell of rabbit retina and its associated amacrine cells. We also observed the relative spread of Neurobiotin injected into a ganglion cell in the presence of modulators of gap junctional permeability. We found that gap junctions between amacrine cells were closed via stimulation of a D1 dopamin...

  8. Characterization of cytochrome c as marker for retinal cell degeneration by uv/vis spectroscopic imaging

    Science.gov (United States)

    Hollmach, Julia; Schweizer, Julia; Steiner, Gerald; Knels, Lilla; Funk, Richard H. W.; Thalheim, Silko; Koch, Edmund

    2011-07-01

    Retinal diseases like age-related macular degeneration have become an important cause of visual loss depending on increasing life expectancy and lifestyle habits. Due to the fact that no satisfying treatment exists, early diagnosis and prevention are the only possibilities to stop the degeneration. The protein cytochrome c (cyt c) is a suitable marker for degeneration processes and apoptosis because it is a part of the respiratory chain and involved in the apoptotic pathway. The determination of the local distribution and oxidative state of cyt c in living cells allows the characterization of cell degeneration processes. Since cyt c exhibits characteristic absorption bands between 400 and 650 nm wavelength, uv/vis in situ spectroscopic imaging was used for its characterization in retinal ganglion cells. The large amount of data, consisting of spatial and spectral information, was processed by multivariate data analysis. The challenge consists in the identification of the molecular information of cyt c. Baseline correction, principle component analysis (PCA) and cluster analysis (CA) were performed in order to identify cyt c within the spectral dataset. The combination of PCA and CA reveals cyt c and its oxidative state. The results demonstrate that uv/vis spectroscopic imaging in conjunction with sophisticated multivariate methods is a suitable tool to characterize cyt c under in situ conditions.

  9. Tyro3 Modulates Mertk-Associated Retinal Degeneration.

    Directory of Open Access Journals (Sweden)

    Douglas Vollrath

    2015-12-01

    Full Text Available Inherited photoreceptor degenerations (IPDs are the most genetically heterogeneous of Mendelian diseases. Many IPDs exhibit substantial phenotypic variability, but the basis is usually unknown. Mutations in MERTK cause recessive IPD phenotypes associated with the RP38 locus. We have identified a murine genetic modifier of Mertk-associated photoreceptor degeneration, the C57BL/6 (B6 allele of which acts as a suppressor. Photoreceptors degenerate rapidly in Mertk-deficient animals homozygous for the 129P2/Ola (129 modifier allele, whereas animals heterozygous for B6 and 129 modifier alleles exhibit an unusual intermixing of degenerating and preserved retinal regions, with females more severely affected than males. Mertk-deficient mice homozygous for the B6 modifier allele display degeneration only in the far periphery, even at 8 months of age, and have improved retinal function compared to animals homozygous for the 129 allele. We genetically mapped the modifier to an approximately 2-megabase critical interval that includes Tyro3, a paralog of Mertk. Tyro3 expression in the outer retina varies with modifier genotype in a manner characteristic of a cis-acting expression quantitative trait locus (eQTL, with the B6 allele conferring an approximately three-fold higher expression level. Loss of Tyro3 function accelerates the pace of photoreceptor degeneration in Mertk knockout mice, and TYRO3 protein is more abundant in the retinal pigment epithelium (RPE adjacent to preserved central retinal regions of Mertk knockout mice homozygous for the B6 modifier allele. Endogenous human TYRO3 protein co-localizes with nascent photoreceptor outer segment (POS phagosomes in a primary RPE cell culture assay, and expression of murine Tyro3 in cultured cells stimulates phagocytic ingestion of POS. Our findings demonstrate that Tyro3 gene dosage modulates Mertk-associated retinal degeneration, provide strong evidence for a direct role for TYRO3 in RPE phagocytosis

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  1. File list: Pol.Neu.20.AllAg.Superior_Cervical_Ganglion [Chip-atlas[Archive

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  12. File list: Oth.Neu.20.AllAg.Superior_Cervical_Ganglion [Chip-atlas[Archive

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  13. Correspondence between visual and electrical input filters of ON and OFF mouse retinal ganglion cells

    Science.gov (United States)

    Sekhar, S.; Jalligampala, A.; Zrenner, E.; Rathbun, D. L.

    2017-08-01

    Objective. Over the past two decades retinal prostheses have made major strides in restoring functional vision to patients blinded by diseases such as retinitis pigmentosa. Presently, implants use single pulses to activate the retina. Though this stimulation paradigm has proved beneficial to patients, an unresolved problem is the inability to selectively stimulate the on and off visual pathways. To this end our goal was to test, using white noise, voltage-controlled, cathodic, monophasic pulse stimulation, whether different retinal ganglion cell (RGC) types in the wild type retina have different electrical input filters. This is an important precursor to addressing pathway-selective stimulation. Approach. Using full-field visual flash and electrical and visual Gaussian noise stimulation, combined with the technique of spike-triggered averaging (STA), we calculate the electrical and visual input filters for different types of RGCs (classified as on, off or on-off based on their response to the flash stimuli). Main results. Examining the STAs, we found that the spiking activity of on cells during electrical stimulation correlates with a decrease in the voltage magnitude preceding a spike, while the spiking activity of off cells correlates with an increase in the voltage preceding a spike. No electrical preference was found for on-off cells. Comparing STAs of wild type and rd10 mice revealed narrower electrical STA deflections with shorter latencies in rd10. Significance. This study is the first comparison of visual cell types and their corresponding temporal electrical input filters in the retina. The altered input filters in degenerated rd10 retinas are consistent with photoreceptor stimulation underlying visual type-specific electrical STA shapes in wild type retina. It is therefore conceivable that existing implants could target partially degenerated photoreceptors that have only lost their outer segments, but not somas, to selectively activate the on and off

  14. Characterization of intravitreally delivered capsid mutant AAV2-Cre vector to induce tissue-specific mutations in murine retinal ganglion cells.

    Science.gov (United States)

    Langouet-Astrie, Christophe J; Yang, Zhiyong; Polisetti, Sraavya M; Welsbie, Derek S; Hauswirth, William W; Zack, Donald J; Merbs, Shannath L; Enke, Raymond A

    2016-10-01

    Targeted expression of Cre recombinase in murine retinal ganglion cells (RGCs) by viral vector is an effective strategy for creating tissue-specific gene knockouts for investigation of genetic contribution to RGC degeneration associated with optic neuropathies. Here we characterize dosage, efficacy and toxicity for sufficient intravitreal delivery of a capsid mutant Adeno-associated virus 2 (AAV2) vector encoding Cre recombinase. Wild type and Rosa26 (R26) LacZ mice were intravitreally injected with capsid mutant AAV2 viral vectors. Murine eyes were harvested at intervals ranging from 2 weeks to 15 weeks post-injection and were assayed for viral transduction, transgene expression and RGC survival. 10(9) vector genomes (vg) were sufficient for effective in vivo targeting of murine ganglion cell layer (GCL) retinal neurons. Transgene expression was observed as early as 2 weeks post-injection of viral vectors and persisted to 11 weeks. Early expression of Cre had no significant effect on RGC survival, while significant RGC loss was detected beginning 5 weeks post-injection. Early expression of viral Cre recombinase was robust, well-tolerated and predominantly found in GCL neurons suggesting this strategy can be effective in short-term RGC-specific mutation studies in experimental glaucoma models such as optic nerve crush and transection experiments. RGC degeneration with Cre expression for more than 4 weeks suggests that Cre toxicity is a limiting factor for targeted mutation strategies in RGCs. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Ganglion Plexus Ablation in Advanced Atrial Fibrillation: The AFACT Study

    NARCIS (Netherlands)

    Driessen, Antoine H. G.; Berger, Wouter R.; Krul, Sébastien P. J.; van den Berg, Nicoline W. E.; Neefs, Jolien; Piersma, Femke R.; Chan Pin Yin, Dean R. P. P.; de Jong, Jonas S. S. G.; van Boven, WimJan P.; de Groot, Joris R.

    2016-01-01

    Patients with long duration of atrial fibrillation (AF), enlarged atria, or failed catheter ablation have advanced AF and may require more extensive treatment than pulmonary vein isolation. The aim of this study was to investigate the efficacy and safety of additional ganglion plexus (GP) ablation

  16. A Comparative Analysis of Ganglion Cell Complex Parameters in ...

    African Journals Online (AJOL)

    Aim: To evaluate the differences between ganglion cell complex (GCC) of primary open angle glaucoma and ocular disorders affecting the macula. Methods and Materials: Forty-seven patients diagnosed with primary open angle glaucoma and 27 patients with macular diseases of different aetiology were enrolled in this ...

  17. Processing of natural temporal stimuli by macaque retinal ganglion cells

    NARCIS (Netherlands)

    Hateren, J.H. van; Rüttiger, L.; Lee, B.B.

    2002-01-01

    This study quantifies the performance of primate retinal ganglion cells in response to natural stimuli. Stimuli were confined to the temporal and chromatic domains and were derived from two contrasting environments, one typically northern European and the other a flower show. The performance of the

  18. Bilateral ganglion cyst of the common peroneal nerve

    Energy Technology Data Exchange (ETDEWEB)

    Pedrazzini, Massimo; Cusmano, Ferdinando; Armaroli, Sara; Pavone, Paolo [Institute of Radiology, University of Parma, Viale Gramsci 14, 43100 Parma (Italy); Pogliacomi, Francesco; Rinaldi, Elio [Institute of Clinical Orthopedics and Traumatology, University of Parma, Viale Gramsci 14, 43100 Parma (Italy)

    2002-11-01

    Ganglion cysts of the common peroneal nerve are rarely described in the literature and a bilateral lesion has not been previously reported. We present a case of a 41-year-old man with a bilateral cyst of the common peroneal nerve diagnosed with ultrasound and magnetic resonance imaging. (orig.)

  19. Encoding visual information in retinal ganglion cells with prosthetic stimulation

    Science.gov (United States)

    Freeman, Daniel K.; Rizzo, Joseph F., III; Fried, Shelley I.

    2011-06-01

    Retinal prostheses aim to restore functional vision to those blinded by outer retinal diseases using electric stimulation of surviving retinal neurons. The ability to replicate the spatiotemporal pattern of ganglion cell spike trains present under normal viewing conditions is presumably an important factor for restoring high-quality vision. In order to replicate such activity with a retinal prosthesis, it is important to consider both how visual information is encoded in ganglion cell spike trains, and how retinal neurons respond to electric stimulation. The goal of the current review is to bring together these two concepts in order to guide the development of more effective stimulation strategies. We review the experiments to date that have studied how retinal neurons respond to electric stimulation and discuss these findings in the context of known retinal signaling strategies. The results from such in vitro studies reveal the advantages and disadvantages of activating the ganglion cell directly with the electric stimulus (direct activation) as compared to activation of neurons that are presynaptic to the ganglion cell (indirect activation). While direct activation allows high temporal but low spatial resolution, indirect activation yields improved spatial resolution but poor temporal resolution. Finally, we use knowledge gained from in vitro experiments to infer the patterns of elicited activity in ongoing human trials, providing insights into some of the factors limiting the quality of prosthetic vision.

  20. The molecular genetic basis of age-related macular degeneration ...

    Indian Academy of Sciences (India)

    Keywords. AMD; epidemiology; genes; polymorphism; risk. Abstract. Age-related macular degeneration (AMD) is a complex disorder of the eye and the third leading cause of blindness worldwide. With a multifactorial etiology, AMD results in progressive loss of central vision affecting the macular region of the eye in elderly.

  1. Petrosal Ganglion: a more complex role than originally imagined.

    Directory of Open Access Journals (Sweden)

    Mauricio Antonio Retamal

    2014-12-01

    Full Text Available The petrosal ganglion is a peripheral sensory ganglion, composed of pseudomonopolar sensory neurons that innervate the posterior third of the tongue and the carotid sinus and body. According to their electrical properties petrosal ganglion neurons can be ascribed to one of two categories: i neurons with action potentials presenting an inflection (hump on its repolarizing phase and ii neurons with fast and brisk action potentials. Although there is some correlation between the electrophysiological properties and the sensory modality of the neurons in some species, no general pattern can be easily recognized. On the other hand, petrosal neurons projecting to the carotid body are activated by several transmitters, with acetylcholine and ATP being the most conspicuous in most species. Petrosal neurons are completely surrounded by a multi-cellular sheet of glial (satellite cells that prevents the formation of chemical or electrical synapses between neurons. Thus, petrosal ganglion neurons are regarded as mere wires that communicate the periphery (i.e., carotid body and the central nervous system. However, it has been shown that in other sensory ganglia satellite glial cells and their neighboring neurons can interact, partly by the release of chemical neuro-glio transmitters. This intercellular communication can potentially modulate the excitatory status of sensory neurons and thus the afferent discharge. In this mini review, we will briefly summarize the general properties of petrosal ganglion neurons and the current knowledge about the glial-neuron communication in sensory neurons and how this phenomenon could be important in the chemical sensory processing generated in the carotid body.

  2. Age-related macular degeneration

    DEFF Research Database (Denmark)

    la Cour, Morten; Kiilgaard, Jens Folke; Nissen, Mogens Holst

    2002-01-01

    Age-related macular degeneration (AMD) is a common macular disease affecting elderly people in the Western world. It is characterised by the appearance of drusen in the macula, accompanied by choroidal neovascularisation (CNV) or geographic atrophy. The disease is more common in Caucasian...

  3. Age-related macular degeneration

    Directory of Open Access Journals (Sweden)

    Wanjiku Mathenge

    2014-12-01

    Full Text Available Age-related macular degeneration (AMD is a disease of the retina that usually develops in people aged 60 years and older. It affects about 8.7% of the world’s population and is the leading cause of blindness among people aged 50 and older in industrialised countries.

  4. Age-Related Macular Degeneration.

    Science.gov (United States)

    Mehta, Sonia

    2015-09-01

    Age-related macular degeneration (AMD) is the leading cause of vision loss in the elderly. AMD is diagnosed based on characteristic retinal findings in individuals older than 50. Early detection and treatment are critical in increasing the likelihood of retaining good and functional vision. Copyright © 2015 Elsevier Inc. All rights reserved.

  5. Degenerated differential pair with controllable transconductance

    NARCIS (Netherlands)

    Mensink, Clemens; Mensink, Clemens H.J.; Nauta, Bram

    1998-01-01

    A differential pair with input transistors and provided with a variable degeneration resistor. The degeneration resistor comprises a series arrangement of two branches of coupled resistors which are shunted in mutually corresponding points by respective control transistors whose gates are

  6. [Progression of nerve fiber layer defects in retrobulbar optic neuritis by the macular ganglion cell complex].

    Science.gov (United States)

    Hong, D; Bosc, C; Chiambaretta, F

    2017-11-01

    Recent studies with SD OCT had shown early axonal damage to the macular ganglion cell complex (which consists of the three innermost layers of the retina: Inner Plexiform Layer [IPL], Ganglion Cell Layer [GCL], Retinal Nerve Fibre layer [RNFL]) in optic nerve pathology. Retrobulbar optic neuritis (RBON), occurring frequently in demyelinating diseases, leads to atrophy of the optic nerve fibers at the level of the ganglion cell axons, previously described in the literature. The goal of this study is to evaluate the progression of optic nerve fiber defects and macular ganglion cell complex defects with the SPECTRALIS OCT via a reproducible method by calculating a mean thickness in each quadrant after an episode of retrobulbar optic neuritis. This is a prospective monocentric observational study including 8 patients at the Clermont-Ferrand university medical center. All patients underwent ocular examination with macular and disc OCT analysis and a Goldmann visual field at the time of inclusion (onset or recurrence of RBON), at 3 months and at 6 months. Patients were 40-years-old on average at the time of inclusion. After 6 months of follow-up, there was progression of the atrophy of the macular ganglion cell complex in the affected eye on (11.5% or 11μm) predominantly inferonasally (13.9% or 16μm) and superonasally (12.9% or 14μm) while the other eye remained stable. The decrease in thickness occurred mainly in the most internal 3 layers of the retina. On average, the loss in thickness of the peripapillary RNFL was predominantly inferotemporal (24.9% or 39μm) and superotemporal (21.8% or 28μm). In 3 months of progression, the loss of optic nerve fibers is already seen on macular and disc OCT after an episode of RBON, especially in inferior quadrants in spite of the improvement in the Goldmann visual field and visual acuity. Segmentation by quadrant was used here to compare the progression of the defect by region compared to the fovea in a global and reproducible

  7. The Relationship Between Insertion Angles, Default Frequency Allocations, and Spiral Ganglion Place Pitch in Cochlear Implants.

    Science.gov (United States)

    Landsberger, David M; Svrakic, Maja; Roland, J Thomas; Svirsky, Mario

    2015-01-01

    Commercially available cochlear implant systems attempt to deliver frequency information going down to a few hundred Hertz, but the electrode arrays are not designed to reach the most apical regions of the cochlea, which correspond to these low frequencies. This may cause a mismatch between the frequencies presented by a cochlear implant electrode array and the frequencies represented at the corresponding location in a normal-hearing cochlea. In the following study, the mismatch between the frequency presented at a given cochlear angle and the frequency expected by an acoustic hearing ear at the corresponding angle is examined for the cochlear implant systems that are most commonly used in the United States. The angular insertion of each of the electrodes on four different electrode arrays (MED-EL Standard, MED-EL Flex28, Advanced Bionics HiFocus 1J, and Cochlear Contour Advance) was estimated from X-ray. For the angular location of each electrode on each electrode array, the predicted spiral ganglion frequency was estimated. The predicted spiral ganglion frequency was compared with the center frequency provided by the corresponding electrode using the manufacturer's default frequency-to-electrode allocation. Differences across devices were observed for the place of stimulation for frequencies below 650 Hz. Longer electrode arrays (i.e., the MED-EL Standard and Flex28) demonstrated smaller deviations from the spiral ganglion map than the other electrode arrays. For insertion angles up to approximately 270°, the frequencies presented at a given location were typically approximately an octave below what would be expected by a spiral ganglion frequency map, while the deviations were larger for angles deeper than 270°. For frequencies above 650 Hz, the frequency to angle relationship was consistent across all four electrode models. A mismatch was observed between the predicted frequency and the default frequency provided by every electrode on all electrode arrays

  8. Direct Reprogramming of Spiral Ganglion Non-neuronal Cells into Neurons: Toward Ameliorating Sensorineural Hearing Loss by Gene Therapy

    Directory of Open Access Journals (Sweden)

    Teppei Noda

    2018-02-01

    Full Text Available Primary auditory neurons (PANs play a critical role in hearing by transmitting sound information from the inner ear to the brain. Their progressive degeneration is associated with excessive noise, disease and aging. The loss of PANs leads to permanent hearing impairment since they are incapable of regenerating. Spiral ganglion non-neuronal cells (SGNNCs, comprised mainly of glia, are resident within the modiolus and continue to survive after PAN loss. These attributes make SGNNCs an excellent target for replacing damaged PANs through cellular reprogramming. We used the neurogenic pioneer transcription factor Ascl1 and the auditory neuron differentiation factor NeuroD1 to reprogram SGNNCs into induced neurons (iNs. The overexpression of both Ascl1 and NeuroD1 in vitro generated iNs at high efficiency. Transcriptome analyses revealed that iNs displayed a transcriptome profile resembling that of endogenous PANs, including expression of several key markers of neuronal identity: Tubb3, Map2, Prph, Snap25, and Prox1. Pathway analyses indicated that essential pathways in neuronal growth and maturation were activated in cells upon neuronal induction. Furthermore, iNs extended projections toward cochlear hair cells and cochlear nucleus neurons when cultured with each respective tissue. Taken together, our study demonstrates that PAN-like neurons can be generated from endogenous SGNNCs. This work suggests that gene therapy can be a viable strategy to treat sensorineural hearing loss caused by degeneration of PANs.

  9. The novel cyclophilin D inhibitor compound 19 protects retinal pigment epithelium cells and retinal ganglion cells from UV radiation.

    Science.gov (United States)

    Xie, Laiqing; Cheng, Long; Xu, Guoxu; Zhang, Ji; Ji, Xiaoyan; Song, E

    2017-06-10

    Excessive Ultra violet (UV) radiation induces injuries to retinal pigment epithelium (RPE) cells (RPEs) and retinal ganglion cells (RGCs), causing retinal degeneration. Cyclophilin D (Cyp-D)-dependent mitochondrial permeability transition pore (mPTP) opening mediates UV-induced cell death. In this study, we show that a novel Cyp-D inhibitor compound 19 efficiently protected RPEs and RGCs from UV radiation. Compound 19-mediated cytoprotection requires Cyp-D, as it failed to further protect RPEs/RGCs from UV when Cyp-D was silenced by targeted shRNAs. Compound 19 almost blocked UV-induced p53-Cyp-D mitochondrial association, mPTP opening and subsequent cytochrome C release. Further studies showed that compound 19 inhibited UV-induced reactive oxygen species (ROS) production, lipid peroxidation and DNA damage. Together, compound 19 protects RPEs and RGCs from UV radiation, possibly via silencing Cyp-D-regulated intrinsic mitochondrial death pathway. Compound 19 could a lead compound for treating UV-associated retinal degeneration diseases. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Direct Reprogramming of Spiral Ganglion Non-neuronal Cells into Neurons: Toward Ameliorating Sensorineural Hearing Loss by Gene Therapy.

    Science.gov (United States)

    Noda, Teppei; Meas, Steven J; Nogami, Jumpei; Amemiya, Yutaka; Uchi, Ryutaro; Ohkawa, Yasuyuki; Nishimura, Koji; Dabdoub, Alain

    2018-01-01

    Primary auditory neurons (PANs) play a critical role in hearing by transmitting sound information from the inner ear to the brain. Their progressive degeneration is associated with excessive noise, disease and aging. The loss of PANs leads to permanent hearing impairment since they are incapable of regenerating. Spiral ganglion non-neuronal cells (SGNNCs), comprised mainly of glia, are resident within the modiolus and continue to survive after PAN loss. These attributes make SGNNCs an excellent target for replacing damaged PANs through cellular reprogramming. We used the neurogenic pioneer transcription factor Ascl1 and the auditory neuron differentiation factor NeuroD1 to reprogram SGNNCs into induced neurons (iNs). The overexpression of both Ascl1 and NeuroD1 in vitro generated iNs at high efficiency. Transcriptome analyses revealed that iNs displayed a transcriptome profile resembling that of endogenous PANs, including expression of several key markers of neuronal identity: Tubb3, Map2, Prph, Snap25, and Prox1. Pathway analyses indicated that essential pathways in neuronal growth and maturation were activated in cells upon neuronal induction. Furthermore, iNs extended projections toward cochlear hair cells and cochlear nucleus neurons when cultured with each respective tissue. Taken together, our study demonstrates that PAN-like neurons can be generated from endogenous SGNNCs. This work suggests that gene therapy can be a viable strategy to treat sensorineural hearing loss caused by degeneration of PANs.

  11. Sentinel Ganglions in Malignant Tumors of the Oral Cavity

    International Nuclear Information System (INIS)

    Cambrea, M.; Vlad, D.; Hincu, Mihaela; Sivoglo, V.

    2006-01-01

    Full text: Objectives: The use of lymphoscintigraphy in order to show lymphatic invasion, for a better precision of the surgical act as well as for the delimitation of the volumes-target to settle the radio therapeutic treatment. Material And Method: A group of 20 patients (18 men and 2 women) diagnosed with malign tumors of the oral cavity with no clinical adenopathy (N0), investigated clinically and para clinically (laboratory examinations and lymphoscintigraphy associated with bone scintigraphy). The lymphoscintigraphy was performed by the pritumoral injection of 18.5MBq 99m Tc-Nanocoll in 4 points. Before the lymphoscintigraphy was performed each patient had been injected with 750MBq Medronat. The images were taken with a GE eNTEGRA 2.5202. system. Pre-operatory (20 min.) intra vital coloring was performed with metilen blue by peritumoral injection. The surgery addressed to the primary tumor was completed by a supraomohioidian cervical vacuuming. Results: The lymphoscintigraphy showed the lymphatic drain of the malign tumors in 95% of the cases. All malign tumors of the oral cavity drain in the latero-cervical lymphatic ganglions (bilateral), most frequently the sentinel ganglions being found at the level IIb (48%), followed by level III (32%), level I-a (16%) and others (4%).The identification of the lymphatic ganglions pre-operatory by inter vital coloration was of 90.62%. The morphology of the satellite lymphoganglions is closely related to the histological type and the degree of differentiation of the tumors. In the invasive forms the frequency of the nodal metastases varies with the clinical stage of the tumor. In a single case multiple bone metastases were found by scintigraphy fact that led to the change of therapeutic attitude. Conclusions: Lymphoscintigraphy is essential for the settling of the therapeutic attitude towards the malign tumors of the oral cavity, due to: - the early detection of the invaded lymphatic ganglions (83 sentinel ganglions found

  12. Superior cervical gangliectomy induces non-exudative age-related macular degeneration in mice

    Directory of Open Access Journals (Sweden)

    Hernán H. Dieguez

    2018-02-01

    Full Text Available Non-exudative age-related macular degeneration, a prevalent cause of blindness, is a progressive and degenerative disease characterized by alterations in Bruch's membrane, retinal pigment epithelium, and photoreceptors exclusively localized in the macula. Although experimental murine models exist, the vast majority take a long time to develop retinal alterations and, in general, these alterations are ubiquitous, with many resulting from non-eye-specific genetic manipulations; additionally, most do not always reproduce the hallmarks of human age-related macular degeneration. Choroid vessels receive sympathetic innervation from the superior cervical ganglion, which, together with the parasympathetic system, regulates blood flow into the choroid. Choroid blood flow changes have been involved in age-related macular degeneration development and progression. At present, no experimental models take this factor into account. The aim of this work was to analyze the effect of superior cervical gangliectomy (also known as ganglionectomy on the choroid, Bruch's membrane, retinal pigment epithelium and retina. Adult male C57BL/6J mice underwent unilateral superior cervical gangliectomy and a contralateral sham procedure. Although superior cervical gangliectomy induced ubiquitous choroid and choriocapillaris changes, it induced Bruch's membrane thickening, loss of retinal pigment epithelium melanin content and retinoid isomerohydrolase, the appearance of drusen-like deposits, and retinal pigment epithelium and photoreceptor atrophy, exclusively localized in the temporal side. Moreover, superior cervical gangliectomy provoked a localized increase in retinal pigment epithelium and photoreceptor apoptosis, and a decline in photoreceptor electroretinographic function. Therefore, superior cervical gangliectomy recapitulated the main features of human non-exudative age-related macular degeneration, and could become a new experimental model of dry age

  13. Superior cervical gangliectomy induces non-exudative age-related macular degeneration in mice.

    Science.gov (United States)

    Dieguez, Hernán H; Romeo, Horacio E; González Fleitas, María F; Aranda, Marcos L; Milne, Georgia A; Rosenstein, Ruth E; Dorfman, Damián

    2018-02-07

    Non-exudative age-related macular degeneration, a prevalent cause of blindness, is a progressive and degenerative disease characterized by alterations in Bruch's membrane, retinal pigment epithelium, and photoreceptors exclusively localized in the macula. Although experimental murine models exist, the vast majority take a long time to develop retinal alterations and, in general, these alterations are ubiquitous, with many resulting from non-eye-specific genetic manipulations; additionally, most do not always reproduce the hallmarks of human age-related macular degeneration. Choroid vessels receive sympathetic innervation from the superior cervical ganglion, which, together with the parasympathetic system, regulates blood flow into the choroid. Choroid blood flow changes have been involved in age-related macular degeneration development and progression. At present, no experimental models take this factor into account. The aim of this work was to analyze the effect of superior cervical gangliectomy (also known as ganglionectomy) on the choroid, Bruch's membrane, retinal pigment epithelium and retina. Adult male C57BL/6J mice underwent unilateral superior cervical gangliectomy and a contralateral sham procedure. Although superior cervical gangliectomy induced ubiquitous choroid and choriocapillaris changes, it induced Bruch's membrane thickening, loss of retinal pigment epithelium melanin content and retinoid isomerohydrolase, the appearance of drusen-like deposits, and retinal pigment epithelium and photoreceptor atrophy, exclusively localized in the temporal side. Moreover, superior cervical gangliectomy provoked a localized increase in retinal pigment epithelium and photoreceptor apoptosis, and a decline in photoreceptor electroretinographic function. Therefore, superior cervical gangliectomy recapitulated the main features of human non-exudative age-related macular degeneration, and could become a new experimental model of dry age-related macular degeneration, and

  14. Ganglion block. When and how?; Ganglienblockade. Wann und wie?

    Energy Technology Data Exchange (ETDEWEB)

    Bale, R. [Medizinische Universitaet Innsbruck, Sektion fuer Mikroinvasive Therapie Universitaetsklinik fuer Radiologie, Innsbruck (Austria)

    2015-10-15

    Increasing understanding of the anatomy and physiology of neural structures has led to the development of surgical and percutaneous neurodestructive methods in order to target and destroy various components of afferent nociceptive pathways. The dorsal root ganglia and in particular the ganglia of the autonomous nervous system are targets for radiological interventions. The autonomous nervous system is responsible for the regulation of organ functions, sweating, visceral and blood vessel-associated pain. Ganglia of the sympathetic chain and non-myelinized autonomous nerves can be irreversibly destroyed by chemical and thermal ablation. Computed tomography (CT)-guided sympathetic nerve blocks are well established interventional radiological procedures which lead to vasodilatation, reduction of sweating and reduction of pain associated with the autonomous nervous system. Sympathetic blocks are applied for the treatment of various vascular diseases including critical limb ischemia. Other indications for thoracic and lumbar sympathectomy include complex regional pain syndrome (CRPS), chronic tumor associated pain and hyperhidrosis. Neurolysis of the celiac plexus is an effective palliative pain treatment particularly in patients suffering from pancreatic cancer. Percutaneous dorsal root ganglion rhizotomy can be performed in selected patients with radicular pain that is resistant to conventional pharmacological and interventional treatment. (orig.) [German] Anatomische und physiologische Kenntnisse ueber die Funktion von Schmerzbahnen fuehrten zur Entwicklung chirurgischer und perkutaner destruktiver Verfahren, um einzelne Komponenten afferenter Schmerzbahnen anzusteuern bzw. auszuschalten. Neben anderen nervalen Strukturen gelten Hinterstrangganglien und insbesondere die Ganglien des autonomen Nervensystems als Ziele fuer radiologische Interventionen. Das vegetative Nervensystem ist fuer die Organfunktion durch Regulation des Gefaesstonus und fuer die Leitung

  15. Age-Related Change in Vestibular Ganglion Cell Populations in Individuals With Presbycusis and Normal Hearing.

    Science.gov (United States)

    Gluth, Michael B; Nelson, Erik G

    2017-04-01

    We sought to establish that the decline of vestibular ganglion cell counts uniquely correlates with spiral ganglion cell counts, cochlear hair cell counts, and hearing phenotype in individuals with presbycusis. The relationship between aging in the vestibular system and aging in the cochlea is a topic of ongoing investigation. Histopathologic age-related changes the vestibular system may mirror what is seen in the cochlea, but correlations with hearing phenotype and the impact of presbycusis are not well understood. Vestibular ganglion cells, spiral ganglion cells, and cochlear hair cells were counted in specimens from individuals with presbycusis and normal hearing. These were taken from within a large collection of processed human temporal bones. Correlations between histopathology and hearing phenotype were investigated. Vestibular ganglion cell counts were positively correlated with spiral ganglion cell counts and cochlear hair cell counts and were negatively correlated with hearing phenotype. There was no statistical evidence on linear regression to suggest that the relationship between age and cell populations differed significantly according to whether presbycusis was present or not. Superior vestibular ganglion cells were more negatively correlated with age than inferior ganglion cells. No difference in vestibular ganglion cells was noted based on sex. Vestibular ganglion cell counts progressively deteriorate with age, and this loss correlates closely with changes in the cochlea, as well as hearing phenotype. However, these correlations do not appear to be unique in individuals with presbycusis as compared with those with normal hearing.

  16. Methane rescues retinal ganglion cells and limits retinal mitochondrial dysfunction following optic nerve crush.

    Science.gov (United States)

    Wang, Ruobing; Sun, Qinglei; Xia, Fangzhou; Chen, Zeli; Wu, Jiangchun; Zhang, Yuelu; Xu, Jiajun; Liu, Lin

    2017-06-01

    Secondary degeneration is a common event in traumatic central nervous system disorders, which involves neuronal apoptosis and mitochondrial dysfunction. Exogenous methane exerts the therapeutic effects in many organ injury. Our study aims to investigate the potential neuroprotection of methane in a rat model of optic nerve crush (ONC). Adult male Sprague-Dawley rats were subjected to ONC and administrated intraperitoneally with methane-saturated or normal saline (10 ml/kg) once per day for one week after ONC. The retinal ganglion cells (RGCs) density was assessed by hematoxylin and eosin staining and Fluoro-Gold retrogradely labeling. Visual function was evaluated by flash visual evoked potentials (FVEP). The retinal apoptosis was measured by terminal-deoxy-transferase-mediated dUTP nick end labeling (TUNEL) assay and the expression of apoptosis-related factors, such as phosphorylated Bcl-2-associated death promoter (pBAD), phosphorylated glycogen synthase kinase-3β (pGSK-3β), Bcl-2 associated X protein (Bax) and Bcl-2 extra large (Bcl-xL). Retinal mitochondrial function was assessed by the mRNA expressions of peroxisome proliferator-activated receptor gamma coactivator-1α (PGC-1α), nuclear respiratory factor 1 (NRF1) and mitochondrial transcription factor A (TFAM), the mitochondrial DNA (mtDNA) copy number, citrate synthase activity and ATP content. Methane treatment significantly improved the RGC loss and visual dysfunction following ONC. As expected, methane also remarkably inhibited the retinal neural apoptosis, such as the fewer TUNEL-positive cells in ganglion cell layer, accompanied by the up-regulations of anti-apoptotic factors (pGSK-3β, pBAD, Bcl-xL) and the down-regulation of pro-apoptotic factor (Bax). Furthermore, methane treatment suppressed up-regulations of critical mitochondrial components (PGC-1α, NRF1 and TFAM) mRNA and mtDNA copy number, as well as improved the reduction of functional mitochondria markers, including citrate synthase

  17. Light and inherited retinal degeneration

    OpenAIRE

    Paskowitz, D M; LaVail, M M; Duncan, J L

    2006-01-01

    Light deprivation has long been considered a potential treatment for patients with inherited retinal degenerative diseases, but no therapeutic benefit has been demonstrated to date. In the few clinical studies that have addressed this issue, the underlying mutations were unknown. Our rapidly expanding knowledge of the genes and mechanisms involved in retinal degeneration have made it possible to reconsider the potential value of light restriction in specific genetic contexts. This review summ...

  18. Palmar hyperhidrosis treated by noninvasive ultrasound stellate ganglion block.

    Science.gov (United States)

    Heinig, Birgit; Koch, Andrè; Wollina, Uwe

    2016-07-05

    Focal palmar hyperhidrosis is a common and often debilitating eccrine sweat gland disorder with negative impact on quality of life and self-esteem. For treatment of recalcitrant cases, a stellate ganglion block is a nonsurgical alternative. Although this method has only a temporary effect, surgical risks can be avoided. The usual way to perform the block is by ultrasound-guided injection of local anesthetics. Here we describe the use of therapeutic ultrasound at 0.8 MHz for stellate ganglion block. Ultrasound was applied for 1 min unilaterally every other day for 6 days. The efficacy was monitored by video capillaroscopy and Minor's iodine starch test. Treatment was well tolerated and no adverse effects were noted. Sweating was stopped and capillary blood flow increased. The effect lasted for several weeks.

  19. Development of rat embryonic spinal ganglion cells in damaged nerve.

    Science.gov (United States)

    Petrova, E S; Isaeva, E N; Korzhevskii, D E

    2014-09-01

    The development of dissociated cells from rat embryonic spinal ganglion after transplantation to damaged nerve of adult animals was studied using immunohistochemical differentiation markers of neural and glial cells. The cell suspension obtained after dissociation of rat embryonic spinal ganglia (embryonic day 15) was injected into the proximal segment of crushed sciatic nerve. The nerve was damaged by ligation for 40 sec. Progenitor cells were labeled with 5-bromo-2'-deoxyuridine (BrdU) before transplantation. BrdU-immunopositive cells were detected in the nerve trunks of recipients on days 1, 21, and 28 after transplantation. Dissociated cells of rat embryonic spinal ganglion (embryonic day 15) survived for at least 4 weeks after transplantation to the nerve and differentiate into NeuN-immunopositive neurons with morphological properties of sensory neurons and satellite cells containing S100 protein.

  20. Retinal Ganglion Cell Loss in Diabetes Associated with Elevated Homocysteine

    Directory of Open Access Journals (Sweden)

    Kenneth S. Shindler

    2009-11-01

    Full Text Available A number of studies have suggested that homocysteine may be a contributing factor to development of retinopathy in diabetic patients based on observed correlations between elevated homocysteine levels and the presence of retinopathy. The significance of such a correlation remains to be determined, and potential mechanisms by which homocysteine might induce retinopathy have not been well characterized. Ganapathy and colleagues1 used mutant mice that have endogenously elevated homocysteine levels due to heterozygous deletion of the cystathionine-β-synthase gene to examine changes in retinal pathology following induction of diabetes. Their finding that elevated homocysteine levels hastens loss of cells in the retinal ganglion cell layer suggests that toxicity to ganglion cells may warrant further investigation as a potential mechanism of homocysteine enhanced susceptibility to diabetic retinopathy.

  1. High speed coding for velocity by archerfish retinal ganglion cells

    Directory of Open Access Journals (Sweden)

    Kretschmer Viola

    2012-06-01

    Full Text Available Abstract Background Archerfish show very short behavioural latencies in response to falling prey. This raises the question, which response parameters of retinal ganglion cells to moving stimuli are best suited for fast coding of stimulus speed and direction. Results We compared stimulus reconstruction quality based on the ganglion cell response parameters latency, first interspike interval, and rate. For stimulus reconstruction of moving stimuli using latency was superior to using the other stimulus parameters. This was true for absolute latency, with respect to stimulus onset, as well as for relative latency, with respect to population response onset. Iteratively increasing the number of cells used for reconstruction decreased the calculated error close to zero. Conclusions Latency is the fastest response parameter available to the brain. Therefore, latency coding is best suited for high speed coding of moving objects. The quantitative data of this study are in good accordance with previously published behavioural response latencies.

  2. Intrinsically photosensitive retinal ganglion cell function in relation to age

    DEFF Research Database (Denmark)

    Herbst, Kristina; Sander, Birgit; Lund-Andersen, Henrik

    2012-01-01

    The activity of melanopsin containing intrinsically photosensitive ganglion retinal cells (ipRGC) can be assessed by a means of pupil responses to bright blue (appr.480 nm) light. Due to age related factors in the eye, particularly, structural changes of the lens, less light reaches retina. The aim...... of this study was to examine how age and in vivo measured lens transmission of blue light might affect pupil light responses, in particular, mediated by the ipRGC....

  3. Ganglion impar block in patients with chronic coccydynia

    Directory of Open Access Journals (Sweden)

    Nitesh Gonnade

    2017-01-01

    Full Text Available Introduction: Coccydynia refers to pain in the terminal segment of the spinecaused by abnormal sitting and standing posture. Coccydynia is usually managed conservatively, however in nonresponsive patients, ganglion impar block is used as a good alternate modality for pain relief. This article studies the effect of ganglion impar block in coccydynia patients who were not relieved by conservative management. Materials and Methods: The study was carried out at the pain clinic in the departments of Physical Medicine and Rehabilitation and Radiology in a tertiary centre in India.It was a prospective hospital-based study, in which 35 patients with coccydynia were considered for fluoroscopy-guided trans-sacro-coccygeal ganglion impar block. The outcome assessment was done using Numerical Rating Scale (NRS and Oswestry Disability Index (ODI scores for a follow-up period of 6 months. Of the 35 patients, 4 were lost to follow-up. Analysis was done usingthe data from the remaining 31 patients. Results: The mean age of the patients suffering from chronic coccydynia was 42.9 ± 8.39 years, and patients' age range was 28–57 years. The mean score of NRS and ODI before the procedure was 7.90 ± 0.16 and 48.97 ± 1.05, respectively. The interquartile range (IQR of NRS score remained almost unchanged during pre and postprocedure, however, IQR of ODI varied during the pre and post procedural events. The NRS and ODI scores immediately after the procedure decreased drastically showing significant pain relief in patients, and the difference of scores till the end of study was statistically significant. Conclusion: This study recommends the trans-sacro-coccygeal “needle inside needle” technique for local anesthetic block of the ganglion impar for pain relief in patients with coccydynia. This should be integrated with rehabilitative measures including ergonomical modification for prolonging pain free period.

  4. Caudal mesenteric ganglion in the sheep - macroanatomical and immunohistochemical study.

    Science.gov (United States)

    Sienkiewicz, W; Chrószcz, A; Dudek, A; Janeczek, M; Kaleczyc, J

    2015-01-01

    The caudal mesenteric ganglion (CaMG) is a prevetrebral ganglion which provides innervation to a number of organs in the abdominal and pelvic cavity. The morphology of CaMG and the chemical coding of neurones in this ganglion have been described in humans and many animal species, but data on this topic in the sheep are entirely lacking. This prompted us to undertake a study to determine the localization and morphology of sheep CaMG as well as immunohistochemical properties of its neurons. The study was carried out on 8 adult sheep, weighing from 40 to 60 kg each. The sheep were deeply anaesthetised and transcardially perfused with 4% paraformaldehyde. CaMG-s were exposed and their location was determined. Macroanatomical observations have revealed that the ovine CaMG is located at the level of last two lumbar (L5 or L6) and the first sacral (S1) vertebrae. The ganglion represents an unpaired structure composed of several, sequentially arranged aggregates of neurons. Immunohistochemical investigations revealed that nearly all (99.5%) the neurons were DβH-IR and were richly supplied by VACHT-IR nerve terminals forming "basket-like" structures around the perikarya. VACHT-IR neurones were not determined. Many neurons (55%) contained immunoreactivity to NPY, some of them (10%) stained for Met-ENK and solitary nerve cells were GAL-positive. CGRP-IR nerve fibres were numerous and a large number of them simultaneously expressed immunoreactivity to SP. Single, weakly stained neurones were SP-IR and only very few nerve cells weakly stained for VIP.

  5. Ganglionic cysts related to the scapula: MR findings

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Ae Kyeong; Kim, Sung Moon; Kim, Kyung Sook; Shin, Myung Jin; Chun, Jae Myeung [Ulsan Univ. College of Medicine, Seoul (Korea, Republic of); Ahn, Joong Mo [Sungkyunkwan Univ. College of Medicine, Seoul (Korea, Republic of)

    1999-07-01

    To evaluate the magnetic resonance (MR) imaging characteristics of ganglionic cysts related to the scapula. We retrospectively reviewed 15 ganglionic cysts diagnosed by MR imaging in 14 patients who subsequently underwent surgical excision (n=8) or needle aspiration (n=1). Five other patients whose lesion-related symptoms were not too severe to manage underwent conservative treatment. We analyzed MR findings with regard to the size, shape and presence of internal septa, the location and signal intensity of the lesion, and associated findings such as change of rotator cuff muscle, labral tear and bone erosion. We also evaluated the presence of tear of rotator cuff tendon, tendinosis, and subacromial enthesophyte. The diameter of ganglionic cysts was 0.5-5.5 (mean, 2.8)cm, and they were round (n=2), ovoid (n=6), or elongated (n=7). Where internal septa were present (n=13), cysts were lobulated. Lesions were located in both scapular and spinoglenoid notches (n=9), only in the scapular notch (n=2), only in the spinoglenoid notch (n=2) or within the bone (n=2). In eleven cases they were very close to the superoposterior aspect of the glenoid labrum (n=11). On T1-weighted images, all lesions were seen to be iso- or hypointense to muscle, while on T2-weighted images, they were hyperintense, resembling joint fluid (n=14), except in one patient with hemorrhage. Associated findings were edema of the infraspinatus muscle (n=4), pressure erosion of the scapular neck (n=1), and labral tear (n=1). A torn supraspinatus tendon (n=2), supraspinatus tendinosis (n=3), and subacromial enthesophyte (n=2) were also present. MR imaging was helpful in diagnosing ganglionic cysts and detecting associated lesions.

  6. Nitric oxide prevents axonal degeneration by inducing HIF-1-dependent expression of erythropoietin.

    Science.gov (United States)

    Keswani, Sanjay C; Bosch-Marcé, Marta; Reed, Nicole; Fischer, Angela; Semenza, Gregg L; Höke, Ahmet

    2011-03-22

    Nitric oxide (NO) is a signaling molecule that can trigger adaptive (physiological) or maladaptive (pathological) responses to stress stimuli in a context-dependent manner. We have previously reported that NO may signal axonal injury to neighboring glial cells. In this study, we show that mice deficient in neuronal nitric oxide synthase (nNOS-/-) are more vulnerable than WT mice to toxin-induced peripheral neuropathy. The administration of NO donors to primary dorsal root ganglion cultures prevents axonal degeneration induced by acrylamide in a dose-dependent manner. We demonstrate that NO-induced axonal protection is dependent on hypoxia-inducible factor (HIF)-1-mediated transcription of erythropoietin (EPO) within glial (Schwann) cells present in the cultures. Transduction of Schwann cells with adenovirus AdCA5 encoding a constitutively active form of HIF-1α results in amelioration of acrylamide-induced axonal degeneration in an EPO-dependent manner. Mice that are partially deficient in HIF-1α (HIF-1α+/-) are also more susceptible than WT littermates to toxic neuropathy. Our results indicate that NO→HIF-1→EPO signaling represents an adaptive mechanism that protects against axonal degeneration.

  7. Compromised Integrity of Central Visual Pathways in Patients With Macular Degeneration.

    Science.gov (United States)

    Malania, Maka; Konrad, Julia; Jägle, Herbert; Werner, John S; Greenlee, Mark W

    2017-06-01

    Macular degeneration (MD) affects the central retina and leads to gradual loss of foveal vision. Although, photoreceptors are primarily affected in MD, the retinal nerve fiber layer (RNFL) and central visual pathways may also be altered subsequent to photoreceptor degeneration. Here we investigate whether retinal damage caused by MD alters microstructural properties of visual pathways using diffusion-weighted magnetic resonance imaging. Six MD patients and six healthy control subjects participated in the study. Retinal images were obtained by spectral-domain optical coherence tomography (SD-OCT). Diffusion tensor images (DTI) and high-resolution T1-weighted structural images were collected for each subject. We used diffusion-based tensor modeling and probabilistic fiber tractography to identify the optic tract (OT) and optic radiations (OR), as well as nonvisual pathways (corticospinal tract and anterior fibers of corpus callosum). Fractional anisotropy (FA) and axial and radial diffusivity values (AD, RD) were calculated along the nonvisual and visual pathways. Measurement of RNFL thickness reveals that the temporal circumpapillary retinal nerve fiber layer was significantly thinner in eyes with macular degeneration than normal. While we did not find significant differences in diffusion properties in nonvisual pathways, patients showed significant changes in diffusion scalars (FA, RD, and AD) both in OT and OR. The results indicate that the RNFL and the white matter of the visual pathways are significantly altered in MD patients. Damage to the photoreceptors in MD leads to atrophy of the ganglion cell axons and to corresponding changes in microstructural properties of central visual pathways.

  8. Corneal and Retinal Neuronal Degeneration in Early Stages of Diabetic Retinopathy.

    Science.gov (United States)

    Srinivasan, Sangeetha; Dehghani, Cirous; Pritchard, Nicola; Edwards, Katie; Russell, Anthony W; Malik, Rayaz A; Efron, Nathan

    2017-12-01

    To examine the neuronal structural integrity of cornea and retina as markers for neuronal degeneration in nonproliferative diabetic retinopathy (NPDR). Participants were recruited from the broader Brisbane community, Queensland, Australia. Two hundred forty-one participants (187 with diabetes and 54 nondiabetic controls) were examined. Diabetic retinopathy (DR) was graded according to the Early Treatment Diabetic Retinopathy Study (ETDRS) scale. Corneal nerve fiber length (CNFL), corneal nerve branch density (CNBD), corneal nerve fiber tortuosity (CNFT), full retinal thickness, retinal nerve fiber layer (RNFL), ganglion cell complex (GCC), focal (FLV) and global loss volumes (GLV), hemoglobin A1c (HbA1c), nephropathy, neuropathy, and cardiovascular measures were examined. The central zone (P = 0.174), parafoveal thickness (P = 0.090), perifovea (P = 0.592), RNFL (P = 0.866), GCC (P = 0.798), and GCC GLV (P = 0.338) did not differ significantly between the groups. In comparison to the control group, those with very mild NPDR and those with mild NPDR had significantly higher focal loss in GCC volume (P = 0.036). CNFL was significantly lower in those with mild NPDR (P = 0.004) in comparison to the control group and those with no DR. The CNBD (P = 0.094) and CNFT (P = 0.458) did not differ between the groups. Both corneal and retinal neuronal degeneration may occur in early stages of diabetic retinopathy. Further studies are required to examine these potential markers for neuronal degeneration in the absence of clinical signs of DR.

  9. Ganglion dynamics and its implications to geologic carbon dioxide storage.

    Science.gov (United States)

    Wang, Yifeng; Bryan, Charles; Dewers, Thomas; Heath, Jason E; Jove-Colon, Carlos

    2013-01-02

    Capillary trapping of a nonwetting fluid phase in the subsurface has been considered as an important mechanism for geologic storage of carbon dioxide (CO(2)). This mechanism can potentially relax stringent requirements for the integrity of cap rocks for CO(2) storage and therefore can significantly enhance storage capacity and security. We here apply ganglion dynamics to understand the capillary trapping of supercritical CO(2) (scCO(2)) under relevant reservoir conditions. We show that, by breaking the injected scCO(2) into small disconnected ganglia, the efficiency of capillary trapping can be greatly enhanced, because the mobility of a ganglion is inversely dependent on its size. Supercritical CO(2) ganglia can be engineered by promoting CO(2)-water interface instability during immiscible displacement, and their size distribution can be controlled by injection mode (e.g., water-alternating-gas) and rate. We also show that a large mobile ganglion can potentially break into smaller ganglia due to CO(2)-brine interface instability during buoyant rise, thus becoming less mobile. The mobility of scCO(2) in the subsurface is therefore self-limited. Vertical structural heterogeneity within a reservoir can inhibit the buoyant rise of scCO(2) ganglia. The dynamics of scCO(2) ganglia described here provides a new perspective for the security and monitoring of subsurface CO(2) storage.

  10. Paracoccygeal corkscrew approach to ganglion impar injections for tailbone pain.

    Science.gov (United States)

    Foye, Patrick M; Patel, Shounuck I

    2009-01-01

    A new technique for performing nerve blocks of the ganglion impar (ganglion Walther) is presented. These injections have been reported to relieve coccydynia (tailbone pain), as well as other malignant and nonmalignant pelvic pain syndromes. A variety of techniques have been previously described for blocking this sympathetic nerve ganglion, which is located in the retrorectal space just anterior to the upper coccygeal segments. Prior techniques have included approaches through the anococcygeal ligament, through the sacrococcygeal joint, and through intracoccygeal joint spaces. This article presents a new, paracoccygeal approach whereby the needle is inserted alongside the coccyx and the needle is guided through three discrete steps with a rotating or corkscrew trajectory. Compared with some of the previously published techniques, this paracoccygeal corkscrew approach has multiple potential benefits, including ease of fluoroscopic guidance using the lateral view, ability to easily use a stylet for the spinal needle, and use of a shorter, thinner needle. While no single technique works best for all patients and each technique has potential advantages and disadvantages, this new technique adds to the available options.

  11. Veratridine increases the survival of retinal ganglion cells in vitro

    Directory of Open Access Journals (Sweden)

    S.P.F. Pereira

    1997-12-01

    Full Text Available Neuronal cell death is an important phenomenon involving many biochemical pathways. This degenerative event has been studied to understand how the cells activate the mechanisms that lead to self-destruction. Target cells and afferent cells play a relevant role in the regulation of natural cell death. We studied the effect of veratridine (1.5, 3.0, 4.5 and 6.0 µM on the survival of neonatal rat retinal ganglion cells in vitro. Veratridine (3.0 µM, a well-known depolarizing agent that opens the Na+ channel, promoted a two-fold increase in the survival of retinal ganglion cells kept in culture for 48 h. This effect was dose-dependent and was blocked by 1.0 µM tetrodotoxin (a classical voltage-dependent Na+ channel blocker and 30.0 µM flunarizine (a Na+ and Ca2+ channel blocker. These results indicate that electrical activity is also important for the maintenance of retinal ganglion cell survival in vitro

  12. Rapid glutamate receptor 2 trafficking during retinal degeneration

    Directory of Open Access Journals (Sweden)

    Lin Yanhua

    2012-02-01

    Full Text Available Abstract Background Retinal degenerations, such as age-related macular degeneration (AMD and retinitis pigmentosa (RP, are characterized by photoreceptor loss and anomalous remodeling of the surviving retina that corrupts visual processing and poses a barrier to late-stage therapeutic interventions in particular. However, the molecular events associated with retinal remodeling remain largely unknown. Given our prior evidence of ionotropic glutamate receptor (iGluR reprogramming in retinal degenerations, we hypothesized that the edited glutamate receptor 2 (GluR2 subunit and its trafficking may be modulated in retinal degenerations. Results Adult albino Balb/C mice were exposed to intense light for 24 h to induce light-induced retinal degeneration (LIRD. We found that prior to the onset of photoreceptor loss, protein levels of GluR2 and related trafficking proteins, including glutamate receptor-interacting protein 1 (GRIP1 and postsynaptic density protein 95 (PSD-95, were rapidly increased. LIRD triggered neuritogenesis in photoreceptor survival regions, where GluR2 and its trafficking proteins were expressed in the anomalous dendrites. Immunoprecipitation analysis showed interaction between KIF3A and GRIP1 as well as PSD-95, suggesting that KIF3A may mediate transport of GluR2 and its trafficking proteins to the novel dendrites. However, in areas of photoreceptor loss, GluR2 along with its trafficking proteins nearly vanished in retracted retinal neurites. Conclusions All together, LIRD rapidly triggers GluR2 plasticity, which is a potential mechanism behind functionally phenotypic revisions of retinal neurons and neuritogenesis during retinal degenerations.

  13. Common Variants in the COL4A4 Gene Confer Susceptibility to Lattice Degeneration of the Retina

    OpenAIRE

    Meguro, Akira; Ideta, Hidenao; Ota, Masao; Ito, Norihiko; Ideta, Ryuichi; Yonemoto, Junichi; Takeuchi, Masaki; Uemoto, Riyo; Nishide, Tadayuki; Iijima, Yasuhito; Kawagoe, Tatsukata; Okada, Eiichi; Shiota, Tomoko; Hagihara, Yuta; Oka, Akira

    2012-01-01

    Lattice degeneration of the retina is a vitreoretinal disorder characterized by a visible fundus lesion predisposing the patient to retinal tears and detachment. The etiology of this degeneration is still uncertain, but it is likely that both genetic and environmental factors play important roles in its development. To identify genetic susceptibility regions for lattice degeneration of the retina, we performed a genome-wide association study (GWAS) using a dense panel of 23,465 microsatellite...

  14. Agmatine protects retinal ganglion cells from hypoxia-induced apoptosis in transformed rat retinal ganglion cell line

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    Kim Chan

    2007-10-01

    Full Text Available Abstract Background Agmatine is an endogenous polyamine formed by the decarboxylation of L-arginine. We investigated the protective effects of agmatine against hypoxia-induced apoptosis of immortalized rat retinal ganglion cells (RGC-5. RGC-5 cells were cultured in a closed hypoxic chamber (5% O2 with or without agmatine. Cell viability was determined by lactate dehydrogenase (LDH assay and apoptosis was examined by annexin V and caspase-3 assays. Expression and phosphorylation of mitogen-activated protein kinases (MAPKs; JNK, ERK p44/42, and p38 and nuclear factor-kappa B (NF-κB were investigated by Western immunoblot analysis. The effects of agmatine were compared to those of brain-derived neurotrophic factor (BDNF, a well-known protective neurotrophin for retinal ganglion cells. Results After 48 hours of hypoxic culture, the LDH assay showed 52.3% cell loss, which was reduced to 25.6% and 30.1% when agmatine and BDNF were administered, respectively. This observed cell loss was due to apoptotic cell death, as established by annexin V and caspase-3 assays. Although total expression of MAPKs and NF-κB was not influenced by hypoxic injury, phosphorylation of these two proteins was increased. Agmatine reduced phosphorylation of JNK and NF-κB, while BDNF suppressed phosphorylation of ERK and p38. Conclusion Our results show that agmatine has neuroprotective effects against hypoxia-induced retinal ganglion cell damage in RGC-5 cells and that its effects may act through the JNK and NF-κB signaling pathways. Our data suggest that agmatine may lead to a novel therapeutic strategy to reduce retinal ganglion cell injury related to hypoxia.

  15. Ganglion of the Flexor Tendon Sheath at the A2 Pulley - Case Report

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    P Gunaseelan

    2015-03-01

    Full Text Available There are few reported cases of flexor tendon sheath ganglion arising from the A2 pulley. We report a case of a flexor tendon sheath ganglion in a 17-year old female who presented with pain, triggering and a swelling at the base of her right ring finger. During the excision biopsy, a ganglion measuring 0.5×0.8×0.4 cm in size was removed from the A2 pulley area.

  16. Expression of Fos protein in the rat central nervous system in response to noxious stimulation: effects of chronic inflammation of the superior cervical ganglion

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    Laudanna A.

    1998-01-01

    Full Text Available The aim of this study was to investigate the possible interactions between the nociceptive system, the sympathetic system and the inflammatory process. Thus, the superior cervical ganglion of rats was submitted to chronic inflammation and Fos expression was used as a marker for neuronal activity throughout central neurons following painful peripheral stimulation. The painful stimulus consisted of subcutaneously injected formalin applied to the supra-ocular region. Fos-positive neurons were identified by conventional immunohistochemical techniques, and analyzed from the obex through the cervical levels of the spinal cord. In the caudal sub-nucleus of the spinal trigeminal nuclear complex, the number of Fos-positive neurons was much higher in rats with inflammation of the superior cervical ganglion than in control rats, either sham-operated or with saline applied to the ganglion. There was a highly significant difference in the density of Fos-positive neurons between the inflamed and control groups. No significant difference was found between control groups. These results suggest that the inflammation of the superior cervical ganglion generated an increased responsiveness to painful stimuli, which may have been due to a diminished sympathetic influence upon the sensory peripheral innervation.

  17. KYNA analogue SZR72 modifies CFA-induced dural inflammation- regarding expression of pERK1/2 and IL-1β in the rat trigeminal ganglion.

    Science.gov (United States)

    Lukács, M; Warfvinge, K; Kruse, L S; Tajti, J; Fülöp, F; Toldi, J; Vécsei, L; Edvinsson, L

    2016-12-01

    Neurogenic inflammation has for decades been considered an important part of migraine pathophysiology. In the present study, we asked the question if administration of a novel kynurenic acid analogue (SZR72), precursor of an excitotoxin antagonist and anti-inflammatory substance, can modify the neurogenic inflammatory response in the trigeminal ganglion. Inflammation in the trigeminal ganglion was induced by local dural application of Complete Freunds Adjuvant (CFA). Levels of phosphorylated MAP kinase pERK1/2 and IL-1β expression in V1 region of the trigeminal ganglion were investigated using immunohistochemistry and Western blot. Pretreatment with one dose of SZR72 abolished the CFA-induced pERK1/2 and IL-1β activation in the trigeminal ganglion. No significant change was noted in case of repeated treatment with SZR72 as compared to a single dose. This is the first study that demonstrates that one dose of KYNA analog before application of CFA can give anti-inflammatory response in a model of trigeminal activation, opening a new line for further investigations regarding possible effects of KYNA derivates.

  18. Intracerebroventricular gene therapy that delays neurological disease progression is associated with selective preservation of retinal ganglion cells in a canine model of CLN2 disease.

    Science.gov (United States)

    Whiting, Rebecca E H; Jensen, Cheryl A; Pearce, Jacqueline W; Gillespie, Lauren E; Bristow, Daniel E; Katz, Martin L

    2016-05-01

    CLN2 disease is one of a group of lysosomal storage disorders called the neuronal ceroid lipofuscinoses (NCLs). The disease results from mutations in the TPP1 gene that cause an insufficiency or complete lack of the soluble lysosomal enzyme tripeptidyl peptidase-1 (TPP1). TPP1 is involved in lysosomal protein degradation, and lack of this enzyme results in the accumulation of protein-rich autofluorescent lysosomal storage bodies in numerous cell types including neurons throughout the central nervous system and the retina. CLN2 disease is characterized primarily by progressive loss of neurological functions and vision as well as generalized neurodegeneration and retinal degeneration. In children the progressive loss of neurological functions typically results in death by the early teenage years. A Dachshund model of CLN2 disease with a null mutation in TPP1 closely recapitulates the human disorder with a progression from disease onset at approximately 4 months of age to end-stage at 10-11 months. Delivery of functional TPP1 to the cerebrospinal fluid (CSF), either by periodic infusion of the recombinant protein or by a single administration of a TPP1 gene therapy vector to the CSF, significantly delays the onset and progression of neurological signs and prolongs life span but does not prevent the loss of vision or modest retinal degeneration that occurs by 11 months of age. In this study we found that in dogs that received the CSF gene therapy treatment, the degeneration of the retina and loss of retinal function continued to progress during the prolonged life spans of the treated dogs. Eventually the normal cell layers of the retina almost completely disappeared. An exception was the ganglion cell layer. In affected dogs that received TPP1 gene therapy to the CSF and survived an average of 80 weeks, ganglion cell axons were present in numbers comparable to those of normal Dachshunds of similar age. The selective preservation of the retinal ganglion cells suggests

  19. Intratendinous ganglion cyst of the extensor digitorum longus tendon: A case report.

    Science.gov (United States)

    Robinson, Cal; Kocialkowski, Cezary; Bhosale, Abhijit; Pillai, Anand

    2016-06-01

    Ganglion cysts are benign lesions, common in the hand and wrist. Intratendinous ganglion, however, are rare. We present the first reported case of an intratendinous ganglion cyst in an extensor digitorum longus (EDL) tendon of the foot. A 35-year old presented with a left-sided painful dorsolateral foot swelling. Ultrasound suggested a ganglion cyst in proximity to the EDL tendon of the 5th toe. Two distinct swellings were identified on surgical exploration, including a 6×1cm ganglion lying within the EDL tendon substance that had resulted in tendon splitting. The lesions were excised and EDL tendon repaired. Histological analysis confirmed that both lesions were ganglion cysts. Post-operative recovery was uneventful. Intratendinous ganglion cysts are rare lesions that pose a unique set of diagnostic and treatment challenges. Unlike conventional ganglion, their diagnosis may not be possible until surgical exploration. They have been reported to increase the risk of spontaneous tendon rupture. As such, a lower operative threshold should be applied to prevent their progression. A high index of suspicion should be applied to any ganglion reported radiologically to be in close contact with tendons. If diagnosed upon surgical exploration, it is essential that the operating surgeon is prepared to appropriately modify the procedure to involve primary tendon repair, tendon transfer or tenodesis. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Revalidation of a modified and safe approach of stellate ganglion block

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    Ashok Jadon

    2011-01-01

    Full Text Available Stellate ganglion block (SGB is very effective in management of chronic regional pain syndrome (CRPS-1. However, serious complication may occur due to accidental intravascular (intra-arterial injection of local anaesthetic agents. Abdi and others, has suggested a modified technique in which fluoroscopy-guided block is given at the junction of uncinate process and body of vertebra at C7 level. In this approach vascular structures remain away from the trajectory of needle and thus avoid accidental vascular injection. We have used this technique of SGB in nine patients who were treated for CRPS-I. The blocks were effective in all the patients all the time without any vascular or other serious complication.

  1. Disc degeneration: current surgical options

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    C Schizas

    2010-10-01

    Full Text Available Chronic low back pain attributed to lumbar disc degeneration poses a serious challenge to physicians. Surgery may be indicated in selected cases following failure of appropriate conservative treatment. For decades, the only surgical option has been spinal fusion, but its results have been inconsistent. Some prospective trials show superiority over usual conservative measures while others fail to demonstrate its advantages. In an effort to improve results of fusion and to decrease the incidence of adjacent segment degeneration, total disc replacement techniques have been introduced and studied extensively. Short-term results have shown superiority over some fusion techniques. Mid-term results however tend to show that this approach yields results equivalent to those of spinal fusion. Nucleus replacement has gained some popularity initially, but evidence on its efficacy is scarce. Dynamic stabilisation, a technique involving less rigid implants than in spinal fusion and performed without the need for bone grafting, represents another surgical option. Evidence again is lacking on its superiority over other surgical strategies and conservative measures. Insertion of interspinous devices posteriorly, aiming at redistributing loads and relieving pain, has been used as an adjunct to disc removal surgery for disc herniation. To date however, there is no clear evidence on their efficacy. Minimally invasive intradiscal thermocoagulation techniques have also been tried, but evidence of their effectiveness is questioned. Surgery using novel biological solutions may be the future of discogenic pain treatment. Collaboration between clinicians and basic scientists in this multidisciplinary field will undoubtedly shape the future of treating symptomatic disc degeneration.

  2. Optimal voltage stimulation parameters for network-mediated responses in wild type and rd10 mouse retinal ganglion cells

    Science.gov (United States)

    Jalligampala, Archana; Sekhar, Sudarshan; Zrenner, Eberhart; Rathbun, Daniel L.

    2017-04-01

    To further improve the quality of visual percepts elicited by microelectronic retinal prosthetics, substantial efforts have been made to understand how retinal neurons respond to electrical stimulation. It is generally assumed that a sufficiently strong stimulus will recruit most retinal neurons. However, recent evidence has shown that the responses of some retinal neurons decrease with excessively strong stimuli (a non-monotonic response function). Therefore, it is necessary to identify stimuli that can be used to activate the majority of retinal neurons even when such non-monotonic cells are part of the neuronal population. Taking these non-monotonic responses into consideration, we establish the optimal voltage stimulation parameters (amplitude, duration, and polarity) for epiretinal stimulation of network-mediated (indirect) ganglion cell responses. We recorded responses from 3958 mouse retinal ganglion cells (RGCs) in both healthy (wild type, WT) and a degenerating (rd10) mouse model of retinitis pigmentosa—using flat-mounted retina on a microelectrode array. Rectangular monophasic voltage-controlled pulses were presented with varying voltage, duration, and polarity. We found that in 4-5 weeks old rd10 mice the RGC thresholds were comparable to those of WT. There was a marked response variability among mouse RGCs. To account for this variability, we interpolated the percentage of RGCs activated at each point in the voltage-polarity-duration stimulus space, thus identifying the optimal voltage-controlled pulse (-2.4 V, 0.88 ms). The identified optimal voltage pulse can activate at least 65% of potentially responsive RGCs in both mouse strains. Furthermore, this pulse is well within the range of stimuli demonstrated to be safe and effective for retinal implant patients. Such optimized stimuli and the underlying method used to identify them support a high yield of responsive RGCs and will serve as an effective guideline for future in vitro investigations of

  3. Lattice degeneration of the retina.

    Science.gov (United States)

    Byer, N E

    1979-01-01

    Lattice degeneration of the retina is the most important of all clinically distinct entities that effect the peripheral fundus and are related to retinal detachment. The purpose of this review is to survey the extensive literature, to evaluate the many diverse opinions on this subject, and to correlate and summarize all the known facts regarding this disease entity. The disease is fully defined and described, both clinically and histologically. Some aspects of the disease are still poorly understood, and some remain controversial, especially in the area of management. For this reason, the indications for treatment are discussed under eight subsections, with a view toward providing practical guidelines for recommendations in management.

  4. Age-related macular degeneration

    DEFF Research Database (Denmark)

    la Cour, Morten; Kiilgaard, Jens Folke; Nissen, Mogens Holst

    2002-01-01

    Age-related macular degeneration (AMD) is a common macular disease affecting elderly people in the Western world. It is characterised by the appearance of drusen in the macula, accompanied by choroidal neovascularisation (CNV) or geographic atrophy. The disease is more common in Caucasian....... Smoking is probably also a risk factor. Preventive strategies using macular laser photocoagulation are under investigation, but their efficacy in preventing visual loss is as yet unproven. There is no treatment with proven efficacy for geographic atrophy. Optimal treatment for exudative AMD requires...

  5. Bovine explant model of degeneration of the intervertebral disc

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    Sivan Sarit

    2008-02-01

    Full Text Available Abstract Background Many new treatments for degeneration of the intervertebral disc are being developed which can be delivered through a needle. These require testing in model systems before being used in human patients. Unfortunately, because of differences in anatomy, there are no ideal animal models of disc degeneration. Bovine explant model systems have many advantages but it is not possible to inject any significant volume into an intact disc. Therefore we have attempted to mimic disc degeneration in an explant bovine model via enzymatic digestion. Methods Bovine coccygeal discs were incubated with different concentrations of the proteolytic enzymes, trypsin and papain, and maintained in culture for up to 3 weeks. A radio-opaque solution was injected to visualise cavities generated. Degenerative features were monitored histologically and biochemically (water and glycosaminoglycan content, via dimethylmethylene blue. Results and Conclusion The central region of both papain and trypsin treated discs was macro- and microscopically fragmented, with severe loss of metachromasia. The integrity of the surrounding tissue was mostly in tact with cells in the outer annulus appearing viable. Biochemical analysis demonstrated greatly reduced glycosaminoglycan content in these compared to untreated discs. We have shown that bovine coccygeal discs, treated with proteolytic enzymes can provide a useful in vitro model system for developing and testing potential new treatments of disc degeneration, such as injectable implants or biological therapies.

  6. Ezh2 does not mediate retinal ganglion cell homeostasis or their susceptibility to injury.

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    Lin Cheng

    Full Text Available Epigenetic predisposition is thought to critically contribute to adult-onset disorders, such as retinal neurodegeneration. The histone methyltransferase, enhancer of zeste homolog 2 (Ezh2, is transiently expressed in the perinatal retina, particularly enriched in retinal ganglion cells (RGCs. We previously showed that embryonic deletion of Ezh2 from retinal progenitors led to progressive photoreceptor degeneration throughout life, demonstrating a role for embryonic predisposition of Ezh2-mediated repressive mark in maintaining the survival and function of photoreceptors in the adult. Enrichment of Ezh2 in RGCs leads to the question if Ezh2 also mediates gene expression and function in postnatal RGCs, and if its deficiency changes RGC susceptibility to cell death under injury or disease in the adult. To test this, we generated mice carrying targeted deletion of Ezh2 from RGC progenitors driven by Math5-Cre (mKO. mKO mice showed no detectable defect in RGC development, survival, or cell homeostasis as determined by physiological analysis, live imaging, histology, and immunohistochemistry. Moreover, RGCs of Ezh2 deficient mice revealed similar susceptibility against glaucomatous and acute optic nerve trauma-induced neurodegeneration compared to littermate floxed or wild-type control mice. In agreement with the above findings, analysis of RNA sequencing of RGCs purified from Ezh2 deficient mice revealed few gene changes that were related to RGC development, survival and function. These results, together with our previous report, support a cell lineage-specific mechanism of Ezh2-mediated gene repression, especially those critically involved in cellular function and homeostasis.

  7. Rac1 selective activation improves retina ganglion cell survival and regeneration.

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    Erika Lorenzetto

    Full Text Available In adult mammals, after optic nerve injury, retinal ganglion cells (RGCs do not regenerate their axons and most of them die by apoptosis within a few days. Recently, several strategies that activate neuronal intracellular pathways were proposed to prevent such degenerative processes. The rho-related small GTPase Rac1 is part of a complex, still not fully understood, intracellular signaling network, mediating in neurons many effects, including axon growth and cell survival. However, its role in neuronal survival and regeneration in vivo has not yet been properly investigated. To address this point we intravitreally injected selective cell-penetrating Rac1 mutants after optic nerve crush and studied the effect on RGC survival and axonal regeneration. We injected two well-characterized L61 constitutively active Tat-Rac1 fusion protein mutants, in which a second F37A or Y40C mutation confers selectivity in downstream signaling pathways. Results showed that, 15 days after crush, both mutants were able to improve survival and to prevent dendrite degeneration, while the one harboring the F37A mutation also improved axonal regeneration. The treatment with F37A mutant for one month did not improve the axonal elongation respect to 15 days. Furthermore, we found an increase of Pak1 T212 phosphorylation and ERK1/2 expression in RGCs after F37A treatment, whereas ERK1/2 was more activated in glial cells after Y40C administration. Our data suggest that the selective activation of distinct Rac1-dependent pathways could represent a therapeutic strategy to counteract neuronal degenerative processes in the retina.

  8. PHOTODYNAMIC THERAPY OF MACULAR DEGENERATION

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    Davorin Sevšek

    2004-05-01

    Full Text Available Background. University Eye Clinic in Ljubljana began to perform a photodynamic therapy (PDT in July 2002. Up to September 2003 there were 51 PDT interventions on 36 eyes. Almost half of the eyes had one or more reinterventions. PDT was used on 29 eyes with age related macular degeneration (AMD. Just before the treatment all of them had visual acuity (VA 6/60 or better and there were predominantly classical or classical choroidal neovascular (CNV membranes. Most VA did not changed significantly in follow-up visits but diameter of CNV membranes was obviously reduced. In macular degeneration due to pathologic myopia (MMD, photodynamic therapy was performed on 7 eyes with mainly occult CNV and VA was 12/60 or better. VA was mostly better in follow-up visits than before treatment with PDT.Conclusions. There were no serious complications during and after PDT interventions. Two patients had back pain during the infusion of Verteporfin but there was no need to stop the intervention.

  9. Age-related macular degeneration

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    Querques G

    2011-05-01

    Full Text Available Giuseppe Querques¹, Fernando Onofrio Avellis1,2, Lea Querques1,3, Francesco Bandello³, Eric H Souied¹ ¹Service d'Ophtalmologie, Centre Hospitalier Intercommunal Créteil, Université Paris-Est Créteil, Créteil, France; ²Parma Eye Clinic University Hospital, Università degli Studi di Parma, Parma, Italy; ³Department of Ophthalmology, Università Vita-Salute San Raffaele Milano, Milano, Italy Date of preparation: March 3, 2011 Conflict of interest: None declaredClinical question: Is there any new knowledge about the pathogenesis and treatment of age-related macular degeneration (AMD?Results: We now understand better the biochemical and pathological pathways involved in the genesis of AMD. Treatment of exudative AMD is based on intravitreal injection of new antivascular endothelial growth factor drugs for which there does not yet exist a unique recognized strategy of administration. No therapies are actually available for atrophic AMD, despite some experimental new pharmacological approaches.Implementation: strategy of administration, safety of intravitreal injectionKeywords: age-related macular degeneration, antivascular endothelial growth factor, choroidal neovascularization, drusen, geographic atrophy

  10. Analysis of the impact responses in a degenerated spinal motion segment FE model

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Young Eun; Choi, Hae Won [Dankook University, Yongin (Korea, Republic of)

    2009-01-15

    A three-dimensional non-linear poroelastic finite element model of an L3/L4 motion segment was used to analyze the biomechanical effects of degeneration under impact loading on the spinal segment. A previously developed degeneration algorithm was applied to generate a degenerated disc model. Regional variation in intact vertebral body bone morphology was simulated by assigning different void ratios of 4.0-5.02, which were assessed for 27 regions of vertebral cancellous bone. For the osteoporotic structure of the vertebral body, the body was divided into 5 regions with 10- 24 void ratios. Different material properties were assigned to the annulus fibers; hereupon our annulus model reflected variation in tensile behavior of multiple layer annulus samples. The impact load applied to the top of the L3 vertebral body was assumed to be a triangular impulsive force with a maximum compressive impact load of 3 kN and 20ms impact duration time. Calculated results indicated that the effect of the degeneration was predominant at the center of the vertebral body. The maximum von Mises stress was found at the region of near the endplate. The degeneration increased the averaged stress at the center of the vertebral body of L3 from 1.54 MPa to 1.69 MPa, the stress remaining relatively small at L4. Decreased fluid volume ratio of the degenerated nucleus tended to increase pressure slightly at the nucleus, and the averaged stress at the nucleus was almost doubled compared to the intact case. The innermost layers of the anterior annulus showed the highest stress concentration, followed by outermost anterior and posterior regions, for both the degenerated and the intact models. Despite an irregular stress distribution in the degenerated model, pore pressure showed relatively uniform distribution

  11. Curcumin inhibits neuronal and vascular degeneration in retina after ischemia and reperfusion injury.

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    Leilei Wang

    Full Text Available Neuron loss, glial activation and vascular degeneration are common sequelae of ischemia-reperfusion (I/R injury in ocular diseases. The present study was conducted to explore the ability of curcumin to inhibit retinal I/R injury, and to investigate underlying mechanisms of the drug effects.Different dosages of curcumin were administered. I/R injury was induced by elevating the intraocular pressure for 60 min followed by reperfusion. Cell bodies, brn3a stained cells and TUNEL positive apoptotic cells in the ganglion cell layer (GCL were quantitated, and the number of degenerate capillaries was assessed. The activation of glial cells was measured by the expression level of GFAP. Signaling pathways including IKK-IκBα, JAK-STAT1/3, ERK/MAPK and the expression levels of β-tubulin III and MCP-1 were measured by western blot analysis. Pre-treatment using 0.01%-0.25% curcumin in diets significantly inhibited I/R-induced cell loss in GCL. 0.05% curcumin pre-treatment inhibited I/R-induced degeneration of retinal capillaries, TUNEL-positive apoptotic cell death in the GCL, brn3a stained cell loss, the I/R-induced up-regulation of MCP-1, IKKα, p-IκBα and p-STAT3 (Tyr, and down-regulation of β-tubulin III. This dose showed no effect on injury-induced GFAP overexpression. Moreover, 0.05% curcumin administered 2 days after the injury also showed a vaso-protective effect.Curcumin protects retinal neurons and microvessels against I/R injury. The beneficial effects of curcumin on neurovascular degeneration may occur through its inhibitory effects on injury-induced activation of NF-κB and STAT3, and on over-expression of MCP-1. Curcumin may therefore serve as a promising candidate for retinal ischemic diseases.

  12. The pterygopalatine ganglion in humans: a morphological study.

    Science.gov (United States)

    Rusu, M C; Pop, F; Curcă, G C; Podoleanu, L; Voinea, L M

    2009-04-01

    As a rule the pterygopalatine ganglion (PPG) is considered to be a single structure of the parasympathetic nervous system, associated with the maxillary nerve in the pterygopalatine fossa (PPF). A few structural studies in humans are available in the indexed references. We designed the present study of the PPG in order to provide evidence of possible variations in morphological patterns of the PPG. We performed dissections of the PPF on 20 human adult heads, using different approaches. The dissected specimens were stained with hematoxylin-eosin and silver (Bielschowsky) or prepared for immunohistochemistry for synaptophisin and neurofilament. Four morphological types of the PPG were defined macroscopically: A (10%): partitioned PPG, the upper partition receiving the vidian nerve; B (55%): single, the upper part (base) receiving the vidian nerve; C (15%): single, but the vidian nerve reaches the lower part (tip) of the ganglion; D (20%): partitioned, the lower partition receiving the vidian nerve. We propose that it may be inappropriate to invariably regard the PPG as a single morphological structure. From individual to individual the PPG may present either as a single ganglion or as a partitioned one, with distinct superior and inferior components. Nevertheless, the presence of the dispersed pterygopalatine microganglia (DPPG) evidenced by histochemistry and immunohistochemistry serves to complete an individually variable morphological pattern of a structure usually described as single. The individual variation may be the reason for failures in ablation procedures of the PPG; partitions of the PPG and/or the DPPG may functionally correlate with specific territories and targets and further tracing studies may be helpful in validating or invalidating this theory.

  13. Pulsed Radiofrequency to the Dorsal Root Ganglion in Acute Herpes Zoster and Postherpetic Neuralgia.

    Science.gov (United States)

    Kim, Koohyun; Jo, Daehyun; Kim, EungDon

    2017-03-01

    Latent varicella zoster virus reactivates mainly in sensory ganglia such as the dorsal root ganglion (DRG) or trigeminal ganglion. The DRG contains many receptor channels and is an important region for pain signal transduction. Sustained abnormal electrical activity to the spinal cord via the DRG in acute herpes zoster can result in neuropathic conditions such as postherpetic neuralgia (PHN). Although the efficacy of pulsed radiofrequency (PRF) application to the DRG in various pain conditions has been previously reported, the application of PRF to the DRG in patients with herpes zoster has not yet been studied. The aim of the present study was to compare the clinical effects of PRF to the DRG in patients with herpes zoster to those of PRF to the DRG in patients with PHN. Retrospective comparative study. University hospital pain center in Korea. The medical records of 58 patients who underwent PRF to the DRG due to zoster related pain (herpes zoster or PHN) were retrospectively analyzed. Patients were divided into 2 groups according to the timing of PRF after zoster onset: an early PRF group (within 90 days) and a PHN PRF group (more than 90 days). The efficacy of PRF was assessed by a numeric rating scale (NRS) and by recording patient medication doses before PRF and at one week, 4 weeks, 8 weeks, and 12 weeks after PRF. Pain intensity was decreased after PRF in all participants. However, the degree of pain reduction was significantly higher in the early PRF group. Moreover, more patients discontinued their medication in the early PRF group, and the PRF success rate was also higher in the early PRF group. The relatively small sample size from a single center, short duration of review of medical records, and the retrospective nature of the study. PRF to the DRG is a useful treatment for treatment-resistant cases of herpes zoster and PHN. Particularly in herpes zoster patients with intractable pain, application of PRF to the DRG should be considered for pain control

  14. Suppressed retinal degeneration in aged wild type and APPswe/PS1ΔE9 mice by bone marrow transplantation.

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    Yue Yang

    Full Text Available Alzheimer's disease (AD is an age-related condition characterized by accumulation of neurotoxic amyloid β peptides (Aβ in brain and retina. Because bone marrow transplantation (BMT results in decreased cerebral Aβ in experimental AD, we hypothesized that BMT would mitigate retinal neurotoxicity through decreased retinal Aβ. To test this, we performed BMT in APPswe/PS1ΔE9 double transgenic mice using green fluorescent protein expressing wild type (wt mice as marrow donors. We first examined retinas from control, non-transplanted, aged AD mice and found a two-fold increase in microglia compared with wt mice, prominent inner retinal Aβ and paired helical filament-tau, and decreased retinal ganglion cell layer neurons. BMT resulted in near complete replacement of host retinal microglia with BMT-derived cells and normalized total AD retinal microglia to non-transplanted wt levels. Aβ and paired helical filament-tau were reduced (61.0% and 44.1% respectively in BMT-recipient AD mice, which had 20.8% more retinal ganglion cell layer neurons than non-transplanted AD controls. Interestingly, aged wt BMT recipients also had significantly more neurons (25.4% compared with non-transplanted aged wt controls. Quantitation of retinal ganglion cell layer neurons in young mice confirmed age-related retinal degeneration was mitigated by BMT. We found increased MHC class II expression in BMT-derived microglia and decreased oxidative damage in retinal ganglion cell layer neurons. Thus, BMT is neuroprotective in age-related as well as AD-related retinal degeneration, and may be a result of alterations in innate immune function and oxidative stress in BMT recipient mice.

  15. Melanopsin-expressing retinal ganglion cells: implications for human diseases

    DEFF Research Database (Denmark)

    La Morgia, Chiara; Ross-Cisneros, Fred N; Hannibal, Jens

    2011-01-01

    interest on these cells, mainly focused on animal models. Only recently, a few studies have started to address the relevance of the mRGC system in humans and related diseases. We recently discovered that mRGCs resist neurodegeneration in two inherited mitochondrial disorders that cause blindness, i......In the last decade, there was the seminal discovery of melanopsin-expressing retinal ganglion cells (mRGCs) as a new class of photoreceptors that subserve the photoentrainment of circadian rhythms and other non-image forming functions of the eye. Since then, there has been a growing research...

  16. The Sphenopalatine Ganglion: Anatomy, Pathophysiology, and Therapeutic Targeting in Headache.

    Science.gov (United States)

    Robbins, Matthew S; Robertson, Carrie E; Kaplan, Eugene; Ailani, Jessica; Charleston, Larry; Kuruvilla, Deena; Blumenfeld, Andrew; Berliner, Randall; Rosen, Noah L; Duarte, Robert; Vidwan, Jaskiran; Halker, Rashmi B; Gill, Nicole; Ashkenazi, Avi

    2016-02-01

    The sphenopalatine ganglion (SPG) has attracted the interest of practitioners treating head and face pain for over a century because of its anatomical connections and role in the trigemino-autonomic reflex. In this review, we discuss the anatomy of the SPG, as well as what is known about its role in the pathophysiology of headache disorders, including cluster headache and migraine. We then address various therapies that target the SPG, including intranasal medication delivery, new SPG blocking catheter devices, neurostimulation, chemical neurolysis, and ablation procedures. © 2015 American Headache Society.

  17. Seborrheic dermatitis treatment with stellate ganglion block: a case report.

    Science.gov (United States)

    Kim, Gun Woo; Mun, Ki Ho; Song, Jeong Yun; Kim, Byung Gun; Jung, Jong Kwon; Lee, Choon Soo; Cha, Young Deog; Song, Jang Ho

    2016-04-01

    Seborrheic dermatitis is a chronic recurrent inflammatory disorder presumed to be caused by increased sebaceous gland secretion, metabolic changes in the cutaneous microflora, and changes in the host immune function. Stellate ganglion block (SGB) is known to increase the blood flow rate without altering the blood pressure, heart rate, or cardiac output, to stabilize hypertonic conditions of the sympathetic nerves, and to affect the endocrine and immune systems. It is used in the differential diagnosis and treatment of autonomic nervous system disorders of the head, neck, and upper limbs. The authors report the first case of successful treatment of a patient with seborrheic dermatitis through repeated SGB trials.

  18. Transgenic inhibition of astroglial NF-κB protects from optic nerve damage and retinal ganglion cell loss in experimental optic neuritis

    Directory of Open Access Journals (Sweden)

    Brambilla Roberta

    2012-09-01

    Full Text Available Abstract Background Optic neuritis is an acute, demyelinating neuropathy of the optic nerve often representing the first appreciable symptom of multiple sclerosis. Wallerian degeneration of irreversibly damaged optic nerve axons leads to death of retinal ganglion cells, which is the cause of permanent visual impairment. Although the specific mechanisms responsible for triggering these events are unknown, it has been suggested that a key pathological factor is the activation of immune-inflammatory processes secondary to leukocyte infiltration. However, to date, there is no conclusive evidence to support such a causal role for infiltrating peripheral immune cells in the etiopathology of optic neuritis. Methods To dissect the contribution of the peripheral immune-inflammatory response versus the CNS-specific inflammatory response in the development of optic neuritis, we analyzed optic nerve and retinal ganglion cells pathology in wild-type and GFAP-IκBα-dn transgenic mice, where NF-κB is selectively inactivated in astrocytes, following induction of EAE. Results We found that, in wild-type mice, axonal demyelination in the optic nerve occurred as early as 8 days post induction of EAE, prior to the earliest signs of leukocyte infiltration (20 days post induction. On the contrary, GFAP-IκBα-dn mice were significantly protected and showed a nearly complete prevention of axonal demyelination, as well as a drastic attenuation in retinal ganglion cell death. This correlated with a decrease in the expression of pro-inflammatory cytokines, chemokines, adhesion molecules, as well as a prevention of NAD(PH oxidase subunit upregulation. Conclusions Our results provide evidence that astrocytes, not infiltrating immune cells, play a key role in the development of optic neuritis and that astrocyte-mediated neurotoxicity is dependent on activation of a transcriptional program regulated by NF-κB. Hence, interventions targeting the NF-κB transcription

  19. Ultrastructure of the ovary of Dermatobia hominis (Diptera: Cuterebridae: III. Gonial cell degeneration

    Directory of Open Access Journals (Sweden)

    V. N. D. P. Secco

    1992-09-01

    Full Text Available We studied the ultrastructural aspects of pre-pupae and pupae ovaries of Dermatobia hominis. Physiological degeneration of gonial cells was observed: (a after the ovarioles differentiation, in the oogonia residing in the apical region of the ovary; (b at the beginning of vitellogenesis, in the cystoblasts close to the terminal filament. The significance of gonial cell degeneration was correlated with the physiological changes wich occur in the ovary during development.

  20. The role of connectivity and stochastic osteocyte behavior in the distribution of perilabyrinthine bone degeneration

    DEFF Research Database (Denmark)

    Bloch, Sune Land; Sørensen, Mads Sølvsten

    2016-01-01

    and the distribution is not entirely smooth and predictable, but rather multifocal and chaotic with a centripetal predilection at the window regions, as in otosclerosis. Based on the observed histological patterns, the fundamental preconditions of perilabyrinthine bone cell behavior can be deduced. When...... observations and the effect of connectivity may account for gradual centripetal degeneration as well as occasional focal degeneration of the cellular anti resorptive signaling pathway around the fluid space of the inner ear and create a permissive environment for otosclerosis....

  1. Salicylate selectively kills cochlear spiral ganglion neurons by paradoxically up-regulating superoxide.

    Science.gov (United States)

    Deng, Lili; Ding, Dalian; Su, Jiping; Manohar, Senthilvelan; Salvi, Richard

    2013-10-01

    Aspirin and its active ingredient salicylate are potent antioxidants that have been reported to be neuro- and otoprotective. However, when consumed in large quantities, these drugs can cause temporary hearing loss and tinnitus. Moreover, recent studies indicate that after several days of treatment, salicylate selectively destroys the spiral ganglion neurons and auditory nerve fibers that relay sounds from the sensory hair cells to the brain. Why salicylate selectively damages spiral ganglion neurons while sparing the hair cells and supports cells is unclear. Here we show that high dose of salicylate trigger an apoptotic response in spiral ganglion neurons characterized morphologically by soma shrinkage and nuclear condensation and fragmentation plus activation of extrinsic initiator caspase-8 and intrinsic initiator caspase-9 several days after the onset of drug treatment. Salicylate treatment triggered an upsurge in the toxic superoxide radical only in spiral ganglion neurons, but not in neighboring hair cells and support cells. Mn TMPyP pentachloride, a cell permeable scavenger of superoxide blocked the expression of superoxide staining in spiral ganglion neurons and almost completely blocked the damage to the nerve fibers and spiral ganglion neurons. NMDA receptor activation is known to increase neuronal superoxide levels. Since NMDA receptors are mainly found on spiral ganglion neurons and since salicylate enhances NMDA receptor currents, the selective killing of spiral ganglion neurons is likely a consequence of enhanced and sustained activation of NMDA receptors by salicylate.

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

    Science.gov (United States)

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

    2015-02-01

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

  3. Target recognition and synapse formation by ciliary-ganglion neurons in tissue culture

    NARCIS (Netherlands)

    Stevens, W.F.; Slaaf, D.W.; Hooisma, J.; Magchielse, T.; Meeter, E.

    1978-01-01

    A less complicated source of neurons suitable for this type of studies is the parasympathetic ciliary ganglion. In the pigeon and in the chick this ganglion is known to contain only two classes of neurons, both of which are cholinoceptive and cholinergic and that innervate the muscle fibres of the

  4. Inflammatory profiles in canine intervertebral disc degeneration

    NARCIS (Netherlands)

    Willems, Nicole; Tellegen, Anna R; Bergknut, Niklas; Creemers, Laura B; Wolfswinkel, Jeannette; Freudigmann, Christian; Benz, Karin; Grinwis, Guy C M; Tryfonidou, Marianna A; Meij, Björn P

    2016-01-01

    BACKGROUND: Intervertebral disc (IVD) disease is a common spinal disorder in dogs and degeneration and inflammation are significant components of the pathological cascade. Only limited studies have studied the cytokine and chemokine profiles in IVD degeneration in dogs, and mainly focused on gene

  5. Genetic association studies in lumbar disc degeneration

    DEFF Research Database (Denmark)

    Eskola, Pasi J; Lemmelä, Susanna; Kjaer, Per

    2012-01-01

    Low back pain is associated with lumbar disc degeneration, which is mainly due to genetic predisposition. The objective of this study was to perform a systematic review to evaluate genetic association studies in lumbar disc degeneration as defined on magnetic resonance imaging (MRI) in humans....

  6. Coding properties of three intrinsically distinct retinal ganglion cells under periodic stimuli: a computational study

    Directory of Open Access Journals (Sweden)

    Lei Wang

    2016-09-01

    Full Text Available As the sole output neurons in the retina, ganglion cells play significant roles in transforming visual information into spike trains, and then transmitting them to the higher visual centers. However, coding strategies that retinal ganglion cells (RGCs adopt to accomplish these processes are not completely clear yet. To clarify these issues, we investigate the coding properties of three types of RGCs (repetitive spiking, tonic firing, and phasic firing by two different measures (spike-rate and spike-latency. Model results show that for periodic stimuli, repetitive spiking RGC and tonic RGC exhibit similar spike-rate patterns. Their spike-rates decrease gradually with increased stimulus frequency, moreover, variation of stimulus amplitude would change the two RGCs’ spike-rate patterns. For phasic RGC, it activates strongly at medium levels of frequency when the stimulus amplitude is low. While if high stimulus amplitude is applied, phasic RGC switches to respond strongly at low frequencies. These results suggest that stimulus amplitude is a prominent factor in regulating RGCs in encoding periodic signals. Similar conclusions can be drawn when analyzes spike-latency patterns of the three RGCs. More importantly, the above phenomena can be accurately reproduced by Hodgkin’s three classes of neurons, indicating that RGCs can perform the typical three classes of firing dynamics, depending on the distinctions of ion channel densities. Consequently, model results from the three RGCs may be not specific, but can also applicable to neurons in other brain regions which exhibit part(s or all of the Hodgkin’s three excitabilities.

  7. Type I vs type II spiral ganglion neurons exhibit differential survival and neuritogenesis during cochlear development

    Directory of Open Access Journals (Sweden)

    Housley Gary D

    2011-10-01

    Full Text Available Abstract Background The mechanisms that consolidate neural circuitry are a major focus of neuroscience. In the mammalian cochlea, the refinement of spiral ganglion neuron (SGN innervation to the inner hair cells (by type I SGNs and the outer hair cells (by type II SGNs is accompanied by a 25% loss of SGNs. Results We investigated the segregation of neuronal loss in the mouse cochlea using β-tubulin and peripherin antisera to immunolabel all SGNs and selectively type II SGNs, respectively, and discovered that it is the type II SGN population that is predominately lost within the first postnatal week. Developmental neuronal loss has been attributed to the decline in neurotrophin expression by the target hair cells during this period, so we next examined survival of SGN sub-populations using tissue culture of the mid apex-mid turn region of neonatal mouse cochleae. In organotypic culture for 48 hours from postnatal day 1, endogenous trophic support from the organ of Corti proved sufficient to maintain all type II SGNs; however, a large proportion of type I SGNs were lost. Culture of the spiral ganglion as an explant, with removal of the organ of Corti, led to loss of the majority of both SGN sub-types. Brain-derived neurotrophic factor (BDNF added as a supplement to the media rescued a significant proportion of the SGNs, particularly the type II SGNs, which also showed increased neuritogenesis. The known decline in BDNF production by the rodent sensory epithelium after birth is therefore a likely mediator of type II neuron apoptosis. Conclusion Our study thus indicates that BDNF supply from the organ of Corti supports consolidation of type II innervation in the neonatal mouse cochlea. In contrast, type I SGNs likely rely on additional sources for trophic support.

  8. Nerve degeneration in inguinal hernia specimens.

    Science.gov (United States)

    Amato, G; Ober, E; Romano, G; Salamone, G; Agrusa, A; Gulotta, G; Bussani, R

    2011-02-01

    The histological study of the herniated inguinal area is rare in the literature. This report is focused on the detection of structural changes of the nerves within tissues bordering the inguinal hernia of cadavers. Their physiopathological consequences are hypothesized. Primary inguinal hernia was diagnosed in 30 fresh cadavers. Tissue specimens from the inguinal region close to and around the hernia opening were excised for histological examination. A control of the data was achieved through tissue samples excised from equivalent sites of the inguinal region in 15 cadavers without hernia. The detected nerves in the inguinal area demonstrated pathological changes such as fibrotic degeneration, atrophy, and fatty dystrophy of the axons. The thickening of the perineural sheath was constantly seen. These findings were consistently present, independent of the hernia type. The detected nerve alterations lead us to imagine a worsening, or even the cessation, of the nervous impulse to the muscles, leading to atrophy and weakening of the abdominal wall. This could represent one of the multifactorial causes of hernia genesis.

  9. Age-related macular degeneration

    DEFF Research Database (Denmark)

    la Cour, Morten; Kiilgaard, Jens Folke; Nissen, Mogens Holst

    2002-01-01

    cause of blindness among Caucasian individuals in developed countries. Blindness resulting from AMD rarely occurs before age 70, and most cases occur after age 80. The age-standardised 1-year incidence of legal blindness resulting from AMD is 212 cases per million. Two-thirds of AMD cases have CNV......Age-related macular degeneration (AMD) is a common macular disease affecting elderly people in the Western world. It is characterised by the appearance of drusen in the macula, accompanied by choroidal neovascularisation (CNV) or geographic atrophy. The disease is more common in Caucasian...... individuals than in pigmented races. In predominantly Caucasian populations, the age-standardised prevalence of AMD in at least one eye is 7760 cases per million. The age-standardised cumulated 1-year incidence of AMD in at least one eye is 1051 cases per million individuals. AMD is the most important single...

  10. Efficacy of Noninvasive Stellate Ganglion Blockade Performed Using Physical Agent Modalities in Patients with Sympathetic Hyperactivity-Associated Disorders: A Systematic Review and Meta-Analysis

    OpenAIRE

    Liao, Chun-De; Tsauo, Jau-Yih; Liou, Tsan-Hon; Chen, Hung-Chou; Rau, Chi-Lun

    2016-01-01

    Background Stellate ganglion blockade (SGB) is mainly used to relieve symptoms of neuropathic pain in conditions such as complex regional pain syndrome and has several potential complications. Noninvasive SGB performed using physical agent modalities (PAMs), such as light irradiation and electrical stimulation, can be clinically used as an alternative to conventional invasive SGB. However, its application protocols vary and its clinical efficacy remains controversial. This study investigated ...

  11. Starburst cells nondirectionally facilitate the responses of direction-selective retinal ganglion cells.

    Science.gov (United States)

    Chiao, Chuan-Chin; Masland, Richard H

    2002-12-15

    The mechanism of direction selectivity in retinal ganglion cells remains controversial. An important issue is how the starburst amacrine cells, which are known to provide a major synaptic input to the direction-selective ganglion cells, participate in the directional discrimination. Here, we present evidence that the cholinergic outputs of the starburst cells affect the responses of the ganglion cells symmetrically; they provide a feedforward excitation that facilitates the response of the ganglion cells to movement in both the preferred and null directions. This seems to place a constraint on models of the directional discrimination in which the starburst cells participate, namely, that their cholinergic synapses be nondirectional in their effects on the ganglion cells.

  12. Omitting histopathology in wrist ganglions. A risky proposition

    Science.gov (United States)

    Zubairi, Akbar J.; Kumar, Santosh; Mohib, Yasir; Rashid, Rizwan H.; Noordin, Shahryar

    2016-01-01

    Objectives: To identify incidence and utility of histopathology in wrist ganglions. Methods: A retrospective study of 112 patients operated for wrist swellings between January 2009 and March 2014 at Aga Khan University Hospital, Karachi, Pakistan, was conducted. Medical records were reviewed for demographics, history, location and associated symptoms, provisional diagnosis and operative details. Histopathology reports were reviewed to confirm the final diagnosis. Results: One hundred and twelve patients were included in the study (34 males and 78 females) with a mean age of 28 ± 12 years. Ninety-five percent of ganglia were dorsally located and 85% were solitary in nature. Histopathology reports confirmed 107 as ganglion cysts, whereas 3 had giant cell tumor of tendon sheath and 2 were reported to be tuberculous tenosynovitis. Conclusion: Although most of the time, the clinical diagnosis conforms to the final diagnosis, the possibility of an alternate diagnosis cannot be ignored (4% in this study). We suggest routine histopathological analysis so that such diagnoses are not missed. PMID:27464871

  13. Lumbosacral intraspinal extradural ganglion cyst in a cat.

    Science.gov (United States)

    de Strobel, Francesca; Taeymans, Olivier; Rosati, Marco; Cherubini, Giunio B

    2015-01-01

    A 16-year-old neutered female domestic shorthair cat was referred for chronic history of reluctance to jump, stiffness of the tail and lower back pain. Mild pelvic limb ataxia, reduced perianal reflex and lumbosacral discomfort were present on neurological examination. On magnetic resonance imaging, a well-defined rounded structure of 3 mm in diameter was identified on the right dorsal aspect of the epidural space at L7-S1, causing displacement of the cauda equina. The lesion was hyperintense to spinal cord parenchyma on T2-weighted images and hypointense on T1-weighted images, consistent with a fluid-filled structure. A Lumbosacral dorsal laminectomy was performed. A clear fluid-containing structure was identified between the right L7 nerve root and the cauda equina. Following surgical excision, histopathology confirmed the cystic nature of the lesion and revealed thick disorganised sheaths of fibrocollagenous tissue and flattened mesenchymal cells lining the luminal part of the cyst wall. A diagnosis of intraspinal ganglion cyst was made. The cat recovered uneventfully. Seven months after surgery euthanasia was performed for unrelated reasons; no neurological deficits were present. This is the first reported case of intraspinal ganglion cyst in a cat. Intraspinal extradural cysts should be considered among other differential diagnoses for cats with lumbosacral myelopathy/radiculopathy.

  14. Intraneural ganglion cyst: a 200-year-old mystery solved.

    Science.gov (United States)

    Spinner, Robert J; Vincent, Jean-François; Wolanskyj, Alexandra P; Scheithauer, Bernd W

    2008-10-01

    We describe the first reported case of an intraneural ganglion cyst, an ulnar ("cubital") intraneural cyst, which, on literature review, dated to 1810. For over 80 years, its original brief description by Beauchêne was wrongly attributed to Duchenne, effectively making the reference and specimen inaccessible to scrutiny. Fortunately, the intact cyst had been safely housed in the Musée Dupuytren, Paris, France, thus permitting its examination. Although originally described as a "serous" cyst, our present understanding of the anatomy of the ulnar nerve and of peripheral nerve pathology allowed us to reinterpret it as a mucin-filled, elbow-level, ulnar intraneural ganglion cyst. In addition to its description as a fusiform cystic enlargement of the nerve, we documented similar enlargement of a lumen-bearing branch, the articular branch at the level of the elbow. Based on our assessment of the specimen and with a modern perspective, we concluded that the origin of the cyst was from the postero-medial aspect of the elbow joint and that its fluid content, having dissected through a capsular defect, followed the path of the articular branch into the parent ulnar nerve. The purpose of this report is to clarify historical misconceptions regarding the pathogenesis of this controversial entity. (c) 2008 Wiley-Liss, Inc.

  15. The circadian response of intrinsically photosensitive retinal ganglion cells.

    Directory of Open Access Journals (Sweden)

    Andrew J Zele

    Full Text Available Intrinsically photosensitive retinal ganglion cells (ipRGC signal environmental light level to the central circadian clock and contribute to the pupil light reflex. It is unknown if ipRGC activity is subject to extrinsic (central or intrinsic (retinal network-mediated circadian modulation during light entrainment and phase shifting. Eleven younger persons (18-30 years with no ophthalmological, medical or sleep disorders participated. The activity of the inner (ipRGC and outer retina (cone photoreceptors was assessed hourly using the pupil light reflex during a 24 h period of constant environmental illumination (10 lux. Exogenous circadian cues of activity, sleep, posture, caffeine, ambient temperature, caloric intake and ambient illumination were controlled. Dim-light melatonin onset (DLMO was determined from salivary melatonin assay at hourly intervals, and participant melatonin onset values were set to 14 h to adjust clock time to circadian time. Here we demonstrate in humans that the ipRGC controlled post-illumination pupil response has a circadian rhythm independent of external light cues. This circadian variation precedes melatonin onset and the minimum ipRGC driven pupil response occurs post melatonin onset. Outer retinal photoreceptor contributions to the inner retinal ipRGC driven post-illumination pupil response also show circadian variation whereas direct outer retinal cone inputs to the pupil light reflex do not, indicating that intrinsically photosensitive (melanopsin retinal ganglion cells mediate this circadian variation.

  16. Lumbosacral intraspinal extradural ganglion cyst in a cat

    Directory of Open Access Journals (Sweden)

    Francesca de Strobel

    2015-09-01

    Full Text Available Case summary A 16-year-old neutered female domestic shorthair cat was referred for chronic history of reluctance to jump, stiffness of the tail and lower back pain. Mild pelvic limb ataxia, reduced perianal reflex and lumbosacral discomfort were present on neurological examination. On magnetic resonance imaging, a well-defined rounded structure of 3 mm in diameter was identified on the right dorsal aspect of the epidural space at L7–S1, causing displacement of the cauda equina. The lesion was hyperintense to spinal cord parenchyma on T2-weighted images and hypointense on T1-weighted images, consistent with a fluid-filled structure. A Lumbosacral dorsal laminectomy was performed. A clear fluid-containing structure was identified between the right L7 nerve root and the cauda equina. Following surgical excision, histopathology confirmed the cystic nature of the lesion and revealed thick disorganised sheaths of fibrocollagenous tissue and flattened mesenchymal cells lining the luminal part of the cyst wall. A diagnosis of intraspinal ganglion cyst was made. The cat recovered uneventfully. Seven months after surgery euthanasia was performed for unrelated reasons; no neurological deficits were present. Relevance and novel information This is the first reported case of intraspinal ganglion cyst in a cat. Intraspinal extradural cysts should be considered among other differential diagnoses for cats with lumbosacral myelopathy/radiculopathy.

  17. Association of HTRA1 rs11200638 with age-related macular degeneration (AMD) in Brazilian patients.

    Science.gov (United States)

    Lana, Tamires Prates; da Silva Costa, Sueli Matilde; Ananina, Galina; Hirata, Fábio Endo; Rim, Priscila Hae Hyun; Medina, Flávio MacCord; de Vasconcellos, José Paulo Cabral; de Melo, Mônica Barbosa

    2018-01-01

    Age-related macular degeneration is a multifactorial disease that can lead to vision impairment in older individuals. Although the etiology of age-related macular degeneration remains unknown, risk factors include age, ethnicity, smoking, hypertension, obesity, and genetic factors. Two main loci have been identified through genome-wide association studies, on chromosomes 1 and 10. Among the variants located at the 10q26 region, rs11200638, located at the HTRA1 gene promoter, has been associated with age-related macular degeneration in several populations and is considered the main polymorphism. We conducted a replication case-control study to analyze the frequency and participation of rs11200638 in the etiology of age-related macular degeneration in a sample of patients and controls from the State of São Paulo, Brazil, through polymerase chain reaction and enzymatic digestion. The frequency of the A allele was 57.60% in patients with age-related macular degeneration and 36.45% in controls (p value macular degeneration group compared to the control group (p = 1.21 e-07 and 0.0357, respectively). No statistically significant results were observed after stratification in dry versus wet types or advanced versus non-advanced forms. To our knowledge, this is the first time the association between rs11200638 and overall age-related macular degeneration has been reported in South America.

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  6. Intra-articular ganglion cysts of the knee: clinical and MR imaging features

    Energy Technology Data Exchange (ETDEWEB)

    Kim, M.G.; Cho, W.H. [Dept. of Radiology, Sanggye Paik Hospital, Inje University, Seoul (Korea); Kim, B.H.; Choi, J.A.; Lee, N.J.; Chung, K.B. [Dept. of Diagnostic Radiology, College of Medicine, Korea University, Seoul (Korea); Choi, Y.S.; Cho, S.B. [Dept. of Radiology, School of Medicine, Eulji University, Seoul (Korea); Lim, H.C. [Dept. of Orthopedic Surgery, College of Medicine, Korea University, Seoul (Korea)

    2001-05-01

    The purpose of this study was to present clinical and MR imaging features of intra-articular ganglion cysts of the knee. Retrospective review of 1685 consecutive medical records and MR examinations of the knee performed at three imaging centers allowed identification of 20 patients (13 men and 7 women; mean age 35 years), in whom evidence of intra-articular ganglion cyst was seen. Of the 20 ganglion cysts, 5 were found in the infrapatellar fat pad, 10 arose from the posterior cruciate ligament, and 5 from the anterior cruciate ligament. Three of five patients with ganglion cyst in the infrapatellar fat pad had a palpable mass. In 7 of 15 patients with ganglion cyst in the intercondylar notch, exacerbation of pain occurred in a squatting position. On four MR arthrographies, ganglion cysts were an intra-articular round, lobulated, low signal intensity lesion. Five cases of fat-suppressed contrast-enhanced T1-weighted SE images demonstrated peripheral thin rim enhancement. The clinical presentation of intra-articular ganglion cyst is varied according to its intra-articular location. The MR appearance of intra-articular ganglion cyst is characteristic and usually associated with the cruciate ligament or the infrapatellar fat pad. Magnetic resonance arthrography has no definite advantage over conventional MR in the evaluation of the lesion. For intra-articular ganglion cyst in the infrapatellar fat pad, fat-suppressed contrast-enhanced MR imaging could be useful, because a thin, rim-enhancing feature of intra-articular ganglion cyst allows it to be distinguished from synovial hemangioma and synovial sarcoma. (orig.)

  7. Quantitative and Topographical Analysis of the Losses of Cone Photoreceptors and Retinal Ganglion Cells Under Taurine Depletion.

    Science.gov (United States)

    Hadj-Saïd, Wahiba; Froger, Nicolas; Ivkovic, Ivana; Jiménez-López, Manuel; Dubus, Élisabeth; Dégardin-Chicaud, Julie; Simonutti, Manuel; Quénol, César; Neveux, Nathalie; Villegas-Pérez, María Paz; Agudo-Barriuso, Marta; Vidal-Sanz, Manuel; Sahel, Jose-Alain; Picaud, Serge; García-Ayuso, Diego

    2016-09-01

    Taurine depletion is known to induce photoreceptor degeneration and was recently found to also trigger retinal ganglion cell (RGC) loss similar to the retinal toxicity of vigabatrin. Our objective was to study the topographical loss of RGCs and cone photoreceptors, with a distinction between the two cone types (S- and L- cones) in an animal model of induced taurine depletion. We used the taurine transporter (Tau-T) inhibitor, guanidoethane sulfonate (GES), to induce taurine depletion at a concentration of 1% in the drinking water. Spectral-domain optical coherence tomography (SD-OCT) and electroretinograms (ERG) were performed on animals after 2 months of GES treatment administered through the drinking water. Retinas were dissected as wholemounts and immunodetection of Brn3a (RGC), S-opsin (S-cones), and L-opsin (L-cones) was performed. The number of Brn3a+ RGCs, and L- and S-opsin+ cones was automatically quantified and their retinal distribution studied using isodensity maps. The treatment resulted in a significant reduction in plasma taurine levels and a profound dysfunction of visual performance as shown by ERG recordings. Optical coherence tomography analysis revealed that the retina was thinner in the taurine-depleted group. S-opsin+cones were more affected (36%) than L-opsin+cones (27%) with greater cone cell loss in the dorsal area whereas RGC loss (12%) was uniformly distributed. This study confirms that taurine depletion causes RGC and cone loss. Electroretinograms results show that taurine depletion induces retinal dysfunction in photoreceptors and in the inner retina. It establishes a gradient of cell loss depending on the cell type from S-opsin+cones, L-opsin+cones, to RGCs. The greater cell loss in the dorsal retina and of the S-cone population may underline different cellular mechanisms of cellular degeneration and suggests that S-cones may be more sensitive to light-induced retinal toxicity enhanced by the taurine depletion.

  8. Isolation and Molecular Profiling of Primary Mouse Retinal Ganglion Cells: Comparison of Phenotypes from Healthy and Glaucomatous Retinas.

    Science.gov (United States)

    Chintalapudi, Sumana R; Djenderedjian, Levon; Stiemke, Andrew B; Steinle, Jena J; Jablonski, Monica M; Morales-Tirado, Vanessa M

    2016-01-01

    Loss of functional retinal ganglion cells (RGC) is an element of retinal degeneration that is poorly understood. This is in part due to the lack of a reliable and validated protocol for the isolation of primary RGCs. Here we optimize a feasible, reproducible, standardized flow cytometry-based protocol for the isolation and enrichment of homogeneous RGC with the Thy1.2(hi)CD48(neg)CD15(neg)CD57(neg) surface phenotype. A three-step validation process was performed by: (1) genomic profiling of 25-genes associated with retinal cells; (2) intracellular labeling of homogeneous sorted cells for the intracellular RGC-markers SNCG, brain-specific homeobox/POU domain protein 3A (BRN3A), TUJ1, and RNA-binding protein with multiple splicing (RBPMS); and (3) by applying the methodology on RGC from a mouse model with elevated intraocular pressure (IOP) and optic nerve damage. Use of primary RGC cultures will allow for future careful assessment of important cell specific pathways in RGC to provide mechanistic insights into the declining of visual acuity in aged populations and those suffering from retinal neurodegenerative diseases.

  9. Isolation and Molecular Profiling of Primary Mouse Retinal Ganglion Cells: Comparison of Phenotypes from Healthy and Glaucomatous Retinas

    Science.gov (United States)

    Chintalapudi, Sumana R.; Djenderedjian, Levon; Stiemke, Andrew B.; Steinle, Jena J.; Jablonski, Monica M.; Morales-Tirado, Vanessa M.

    2016-01-01

    Loss of functional retinal ganglion cells (RGC) is an element of retinal degeneration that is poorly understood. This is in part due to the lack of a reliable and validated protocol for the isolation of primary RGCs. Here we optimize a feasible, reproducible, standardized flow cytometry-based protocol for the isolation and enrichment of homogeneous RGC with the Thy1.2hiCD48negCD15negCD57neg surface phenotype. A three-step validation process was performed by: (1) genomic profiling of 25-genes associated with retinal cells; (2) intracellular labeling of homogeneous sorted cells for the intracellular RGC-markers SNCG, brain-specific homeobox/POU domain protein 3A (BRN3A), TUJ1, and RNA-binding protein with multiple splicing (RBPMS); and (3) by applying the methodology on RGC from a mouse model with elevated intraocular pressure (IOP) and optic nerve damage. Use of primary RGC cultures will allow for future careful assessment of important cell specific pathways in RGC to provide mechanistic insights into the declining of visual acuity in aged populations and those suffering from retinal neurodegenerative diseases. PMID:27242509

  10. N-Acetylcysteine protects inner ear hair cells and spiral ganglion neurons from manganese exposure by regulating ROS levels.

    Science.gov (United States)

    Wang, Weilong; Li, Dan; Ding, Xuerui; Zhao, Qianqian; Chen, Jiawei; Tian, Keyong; Qiu, Yang; Lu, Lianjun

    2017-09-05

    Manganese (Mn) is an indispensable cofactor for many enzymes and a basic factor for many reproductive and metabolic pathways. However, exposure to high concentrations of Mn can result in deleterious effects on the central nervous system and peripheral nerves, including nerves associated with the auditory system. Based on our studies of cochlear organotypic cultures, Mn exposure induces a significant loss of hair cells (HCs), auditory nerve fibers (ANFs) and spiral ganglion neurons (SGNs) in a concentration-dependent manner. Additionally, N-acetylcysteine (NAC), a glutathione (GSH) provider and a direct scavenger of reactive oxygen species (ROS), clearly decreases Mn-induced ROS accumulation, caspase-3 activation and TUNEL staining, which indicate increased cell survival. Based on these results, Mn exposure exerts ototoxic and neurotoxic effects on the auditory system. Furthermore, 20mM NAC may prevent 1mM Mn-induced hair cell loss and axonal degeneration, indicating that NAC could be a promising drug for clinical applications. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Identification of degenerate nuclei and development of a SCAR marker for Flammulina velutipes.

    Directory of Open Access Journals (Sweden)

    Sun Young Kim

    Full Text Available Flammulina velutipes is one of the major edible mushrooms in the world. Recently, abnormalities that have a negative impact on crop production have been reported in this mushroom. These symptoms include slow vegetative growth, a compact mycelial mat, and few or even no fruiting bodies. The morphologies and fruiting capabilities of monokaryons of wild-type and degenerate strains that arose through arthrospore formation were investigated through test crossing. Only one monokaryotic group of the degenerate strains and its hybrid strains showed abnormal phenotypes. Because the monokaryotic arthrospore has the same nucleus as the parent strain, these results indicated that only one aberrant nucleus of the two nuclei in the degenerate strain was responsible for the degeneracy. A sequence-characterized amplified region marker that is linked to the degenerate monokaryon was identified based on a polymorphic sequence that was generated using random primers. Comparative analyses revealed the presence of a degenerate-specific genomic region in a telomere, which arose via the transfer of a genomic fragment harboring a putative helicase gene. Our findings have narrowed down the potential molecular targets responsible for this phenotype for future studies and have provided a marker for the detection of degenerate strains.

  12. Characterizing degenerate Sturm-Liouville problems

    Directory of Open Access Journals (Sweden)

    Angelo B. Mingarelli

    2004-11-01

    Full Text Available Consider the Dirichlet eigenvalue problem associated with the real two-term weighted Sturm-Liouville equation $$-(p(xy'' = lambda r(xy$$ on the finite interval [a,b]. This eigenvalue problem will be called degenerate provided its spectrum fills the whole complex plane. Generally, in degenerate cases the coefficients $p(x, r(x$ must each be sign indefinite on [a,b]. Indeed, except in some special cases, the quadratic forms induced by them on appropriate spaces must also be indefinite. In this note we present a necessary and sufficient condition for this boundary problem to be degenerate. Some extensions are noted.

  13. Morphometric analysis of thoracic ganglion neurons in subjects with and without primary palmar hyperhidrosis.

    Science.gov (United States)

    de Oliveira, Flavio Roberto Garbelini; Moura, Nabor B; de Campos, Jose Ribas M; Wolosker, Nelson; Parra, Edwin R; Capelozzi, Vera L; Pêgo-Fernandes, Paulo

    2014-05-01

    Hyperhidrosis (HH) is a disease whose physiopathology remains poorly understood and that adversely affects quality of life. There is no morphologic study that includes an adequate control group that allows for comparison of the ganglion of HH to those of normal individuals. The purpose of study was to analyze morphologic and morphometric characteristics of the ganglion from patients with HH and normal individuals (organ donators). This was a transversal study. The sympathetic thoracic ganglia were obtained from 2 groups of patients. Group PH (palmar hyperhidrosis), 40 patients with palmar HH submitted to surgery by video-assisted thoracoscopy, and group C (control group), 14 deceased individuals (control group of organ donators) without any history of HH. The third left sympathetic thoracic ganglion was resected in all patients. We observed higher number of cells in the PH group than in the control group (14.25 + 3.81 vs. 10.65 + 4.93) with P = 0.007; the mean percentage of ganglion cells stained by caspases-3 in the PH group was significantly greater than that of the C group (2.37 + 0.79 vs. 0.77 + 0.28) with P ganglion cells within the ganglion and a higher number of cells in apoptosis. Also, the subjects of PH group have less collagen in the sympathetic ganglion when compared with the control group, but not statistically significant. Copyright © 2014 Elsevier Inc. All rights reserved.

  14. Mouse models for cone degeneration.

    Science.gov (United States)

    Samardzija, Marijana; Grimm, Christian

    2014-01-01

    Loss of cone vision has devastating effects on everyday life. Even though much effort has been made to understand cone physiology and pathophysiology, no successful therapies are available for patients suffering from cone disorders. As complex retinal interactions cannot be studied in vitro, utilization of different animal models is inevitable. Due to recent advances in transgenesis, mice became the most popular animal model to study human diseases, also in ophthalmology. While there are similarities in retinal anatomy and pathophysiology between mice and humans, there are also differences, most importantly the lack of a cone-rich macula in mice. Instead, cones in mice are rare and distributed over the whole retina, which makes the analysis of cone pathophysiology very difficult in these animals. This hindrance is one of the reasons why our understanding of rod pathophysiological processes is much more advanced. Recently, however, the sparseness of cones was overcome by the generation of the Nrl (- / -) mouse that expresses only cone photoreceptors in the retina. This paper will give a brief overview of some of the known mouse models to study cone degeneration and discuss the current knowledge gained from the analysis of these models.

  15. Degeneration of biogenic superparamagnetic magnetite.

    Science.gov (United States)

    Li, Y-L; Pfiffner, S M; Dyar, M D; Vali, H; Konhauser, K; Cole, D R; Rondinone, A J; Phelps, T J

    2009-01-01

    Magnetite crystals precipitated as a consequence of Fe(III) reduction by Shewanella algae BrY after 265 h incubation and 5-year anaerobic storage were investigated with transmission electron microscopy, Mössbauer spectroscopy and X-ray diffraction. The magnetite crystals were typically superparamagnetic with an approximate size of 13 nm. The lattice constants of the 265 h and 5-year crystals are 8.4164A and 8.3774A, respectively. The Mössbauer spectra indicated that the 265 h magnetite had excess Fe(II) in its crystal-chemistry (Fe(3+) (1.990)Fe(2+) (1.015)O(4)) but the 5-year magnetite was Fe(II)-deficient in stoichiometry (Fe(3+) (2.388)Fe(2+) (0.419)O(4)). Such crystal-chemical changes may be indicative of the degeneration of superparamagnetic magnetite through the aqueous oxidization of Fe(II) anaerobically, and the concomitant oxidation of the organic phases (fatty acid methyl esters) that were present during the initial formation of the magnetite. The observation of a corona structure on the aged magnetite corroborates the anaerobic oxidation of Fe(II) on the outer layers of magnetite crystals. These results suggest that there may be a possible link between the enzymatic activity of the bacteria and the stability of Fe(II)-excess magnetite, which may help explain why stable nano-magnetite grains are seldom preserved in natural environments.

  16. Degeneration of Biogenic Superparamagnetic Magnetite

    Energy Technology Data Exchange (ETDEWEB)

    Li, Dr. Yi-Liang [University of Tennessee, Knoxville (UTK); Pfiffner, Susan M. [University of Tennessee, Knoxville (UTK); Dyar, Dr. M Darby [Mount Holyoke College; Vali, Dr. Hojatolah [McGill University, Montreal, Quebec; Konhauser, Dr, Kurt [University of Alberta; Cole, David R [ORNL; Rondinone, Adam Justin [ORNL; Phelps, Tommy Joe [ORNL

    2009-01-01

    ABSTRACT. Magnetite crystals precipitated as a consequence of Fe(III) reduction by Shewanella algae BrY after 265 hours incubation and 5-year storage were investigated with transmission electron microscopy, M ssbauer spectroscopy and X-ray diffraction. The magnetite crystals were typically superparamagnetic with an approximate size of 13 nm. The lattice constants of the 265 hour and 5-year crystals are 8.4164 and 8.3774 , respectively. The M ssbauer spectra indicated that the 265 hour magnetite had excess Fe(II) in its crystal-chemistry (Fe3+1.9901Fe2+ 1.0149O4) but the 5-year magnetite was Fe(II)-deficient in stoichiometry (Fe3+2.3875Fe2+0.4188O4). Such crystal-hemical changes may be indicative of the degeneration of superparamagnetic magnetite through the aqueous oxidization of Fe(II) anaerobically, and the concomitant oxidation of the organic phases(fatty acid methyl esters) that were present during the initial formation of the magnetite. The observation of a corona structure on the aged magnetite corroborates the oxidation of Fe(II) on the outer layers of magnetite crystals. These results suggest that there may be a possible link between the enzymatic activity of the bacteria and the stability of Fe(II)-excess magnetite, which may help explain why stable nano-magnetite grains are seldom preserved in natural environments.

  17. Very Degenerate Higgsino Dark Matter

    Energy Technology Data Exchange (ETDEWEB)

    Chun, Eung Jin [Korea Institute for Advanced Study,Seoul 130-722 (Korea, Republic of); Jung, Sunghoon [SLAC National Accelerator Laboratory,Menlo Park, CA 94025 (United States); Kavli Institute for Theoretical Physics,Santa Barbara, CA 93106 (United States); Park, Jong-Chul [Department of Physics, Chungnam National University,Daejeon 34134 (Korea, Republic of)

    2017-01-03

    We present a study of the Very Degenerate Higgsino Dark Matter (DM), whose mass splitting between the lightest neutral and charged components is O(1) MeV, much smaller than radiative splitting of 355 MeV. The scenario is realized in the minimal supersymmetric standard model by small gaugino mixings. In contrast to the pure Higgsino DM with the radiative splitting only, various observable signatures with distinct features are induced. First of all, the very small mass splitting makes (a) sizable Sommerfeld enhancement and Ramsauer-Townsend (RT) suppression relevant to ∼1 TeV Higgsino DM, and (b) Sommerfeld-Ramsauer-Townsend effect saturate at lower velocities v/c≲10{sup −3}. As a result, annihilation signals can be large enough to be observed from the galactic center and/or dwarf galaxies, while the relative signal sizes can vary depending on the locations of Sommerfeld peaks and RT dips. In addition, at collider experiments, stable chargino signatures can be searched for to probe the model in the future. DM direct detection signals, however, depend on the Wino mass; even no detectable signals can be induced if the Wino is heavier than about 10 TeV.

  18. Texture-based quantification of lumbar intervertebral disc degeneration from conventional T2-weighted MRI

    Energy Technology Data Exchange (ETDEWEB)

    Michopoulou, Sofia; Speller, Robert; Todd-Pokropek, Andrew (Dept. of Medical Physics and Bioengineering, University College London (United Kingdom)), e-mail: s.michopoulou@ucl.ac.uk; Costaridou, Lena (Dept. of Medical Physics, School of Medicine, Univ. of Patras (Greece)); Vlychou, Marianna (Dept. of Radiology, Univ. Hospital of Larissa, Univ. of Thessaly (Greece))

    2011-02-15

    Background: Disc degeneration quantification is important for monitoring the effects of new therapeutic methods, such as cell and growth factor therapy. Magnetic resonance (MR) image texture reflects biochemical and structural tissue properties and has been used for differentiating between normal and pathological status in a variety of medical applications. Purpose: To investigate the suitability of textural descriptors for the quantification of intervertebral disc degeneration using conventional T2-weighted magnetic resonance images of the lumbar spine. Material and Methods:: A 3 Tesla scanner was used, and conventional T2- weighted MR images were obtained, and a total of 255 lumbar discs were analyzed. An atlas-based method was used for segmenting the disc regions from the images. A set of first and second order statistics describing texture of each region were calculated. The validity and reliability of these descriptors for disc degeneration severity quantification was tested through their correlation with patient age and qualitative clinical grading of degeneration severity. Texture quantification results were compared to a widely accepted method for disc degeneration quantification based on the measurement of disc's mean signal intensity. Results: Out of the set of texture descriptors tested, two descriptors quantifying image intensity inhomogeneity, i.e. the grey level standard deviation and co-occurrence derived sum of squares displayed the strongest association to patient age and clinical grading of disc degeneration severity (P < 0.001). This is attributed to these inhomogeneity descriptors' capability to capture the progressive loss of nucleus-annulus distinction in the degenerative progress. Statistical analysis indicates that these descriptors can effectively separate between early stages of degeneration. Quantitative measurements are highly repeatable (intraclass correlation >0.98). Conclusion: Inhomogeneity descriptors could be a valuable

  19. Imaging of compound palmar ganglion with pathologic correlation

    Directory of Open Access Journals (Sweden)

    Sourav Talukder

    2014-12-01

    Full Text Available Compound palmar ganglion, or chronic flexor tenosynovitis, most commonly of tuberculousorigin, is a rare extrapulmonary manifestation of tuberculosis (TB. The flexor synovialsheath is not a common site for TB but, once involved, causes rapid involvement of all flexortendons. We discuss the case of a 70-year-old farmer who presented to us with pain and progressive swelling of the palmar aspect of the wrist. On clinical examination, swelling both above and below the proximal wrist crease was found, with positive cross-fluctuation. Onultrasonography and magnetic resonance imaging, features suggestive of compound palmarganglion were present. The patient underwent surgical resection (extensive tenosynovectomyand chemotherapy. Post-operative histopatholgical findings correlated with the radiological features.

  20. Neurogenic inflammation: a study of rat trigeminal ganglion

    DEFF Research Database (Denmark)

    Kristiansen, Kim Anker; Edvinsson, Lars

    2010-01-01

    Calcitonin gene-related peptide (CGRP) is linked to neurogenic inflammation and to migraine. Activation of the trigeminovascular system plays a prominent role during migraine attacks with the release of CGRP. The trigeminal ganglion (TG) contains three main cell types: neurons, satellite glial...... cells (SGC) and Schwann cells; the first two have before been studied in vitro separately. Culture of rat TG provides a method to induce inflammation and the possibility to evaluate the different cell types in the TG simultaneously. We investigated expression levels of various inflammatory cytokines...... inhibitor SP600125. This method may be of value to examine local TG inflammation, putatively involved in the pathophysiology of some forms of primary headaches....

  1. Activation of ganglion cells and axon bundles using epiretinal electrical stimulation.

    Science.gov (United States)

    Grosberg, Lauren E; Ganesan, Karthik; Goetz, Georges A; Madugula, Sasidhar S; Bhaskhar, Nandita; Fan, Victoria; Li, Peter; Hottowy, Pawel; Dabrowski, Wladyslaw; Sher, Alexander; Litke, Alan M; Mitra, Subhasish; Chichilnisky, E J

    2017-09-01

    Epiretinal prostheses for treating blindness activate axon bundles, causing large, arc-shaped visual percepts that limit the quality of artificial vision. Improving the function of epiretinal prostheses therefore requires understanding and avoiding axon bundle activation. This study introduces a method to detect axon bundle activation on the basis of its electrical signature and uses the method to test whether epiretinal stimulation can directly elicit spikes in individual retinal ganglion cells without activating nearby axon bundles. Combined electrical stimulation and recording from isolated primate retina were performed using a custom multielectrode system (512 electrodes, 10-μm diameter, 60-μm pitch). Axon bundle signals were identified by their bidirectional propagation, speed, and increasing amplitude as a function of stimulation current. The threshold for bundle activation varied across electrodes and retinas, and was in the same range as the threshold for activating retinal ganglion cells near their somas. In the peripheral retina, 45% of electrodes that activated individual ganglion cells (17% of all electrodes) did so without activating bundles. This permitted selective activation of 21% of recorded ganglion cells (7% of expected ganglion cells) over the array. In one recording in the central retina, 75% of electrodes that activated individual ganglion cells (16% of all electrodes) did so without activating bundles. The ability to selectively activate a subset of retinal ganglion cells without axon bundles suggests a possible novel architecture for future epiretinal prostheses. NEW & NOTEWORTHY Large-scale multielectrode recording and stimulation were used to test how selectively retinal ganglion cells can be electrically activated without activating axon bundles. A novel method was developed to identify axon activation on the basis of its unique electrical signature and was used to find that a subset of ganglion cells can be activated at single

  2. Hypoxia-ischemia and retinal ganglion cell damage

    Directory of Open Access Journals (Sweden)

    Charanjit Kaur

    2008-08-01

    Full Text Available Charanjit Kaur1, Wallace S Foulds2, Eng-Ang Ling11Department of Anatomy, Yong Loo Lin School of Medicine, National University of Singapore, Singapore; 2Singapore Eye Research Institute, SingaporeAbstract: Retinal hypoxia is the potentially blinding mechanism underlying a number of sight-threatening disorders including central retinal artery occlusion, ischemic central retinal vein thrombosis, complications of diabetic eye disease and some types of glaucoma. Hypoxia is implicated in loss of retinal ganglion cells (RGCs occurring in such conditions. RGC death occurs by apoptosis or necrosis. Hypoxia-ischemia induces the expression of hypoxia inducible factor-1α and its target genes such as vascular endothelial growth factor (VEGF and nitric oxide synthase (NOS. Increased production of VEGF results in disruption of the blood retinal barrier leading to retinal edema. Enhanced expression of NOS results in increased production of nitric oxide which may be toxic to the cells resulting in their death. Excess glutamate release in hypoxic-ischemic conditions causes excitotoxic damage to the RGCs through activation of ionotropic and metabotropic glutamate receptors. Activation of glutamate receptors is thought to initiate damage in the retina by a cascade of biochemical effects such as neuronal NOS activation and increase in intracellular Ca2+ which has been described as a major contributing factor to RGC loss. Excess production of proinflammatory cytokines also mediates cell damage. Besides the above, free-radicals generated in hypoxic-ischemic conditions result in RGC loss because of an imbalance between antioxidant- and oxidant-generating systems. Although many advances have been made in understanding the mediators and mechanisms of injury, strategies to improve the damage are lacking. Measures to prevent neuronal injury have to be developed.Keywords: retinal hypoxia, retinal ganglion cells, glutamate receptors, neuronal injury, retina

  3. Activity patterns of cochlear ganglion neurones in the starling.

    Science.gov (United States)

    Manley, G A; Gleich, O; Leppelsack, H J; Oeckinghaus, H

    1985-09-01

    Spontaneous activity and responses to simple tonal stimuli were studied in cochlear ganglion neurones of the starling. Both regular and irregular spontaneous activity were recorded. Non-auditory cells have their origin in the macula lagenae. Mean spontaneous rate for auditory cells (all irregularly spiking) was 45 spikes s-1. In half the units having characteristic frequencies (CFs) less than 1.5 kHz, time-interval histograms (TIHs) of spontaneous activity showed regularly-spaced peaks or 'preferred' intervals. The spacing of the peak intervals was, on average, 15% greater than the CF-period interval of the respective units. In TIH of lower-frequency cells without preferred intervals, the modal interval was also on average about 15% longer than the CF-period interval. Apparently, the resting oscillation frequency of these cells lies below their CF. Tuning curves (TCs) of neurones to short tone bursts show no systematic asymmetry as in mammals. Below CF 1 kHz, the low-frequency flanks of the TCs are, on average, steeper than the high-frequency flanks. Above CF 1 kHz, the reverse is true. The cochlear ganglion and nerve are tonotopically organized. Low-frequency fibres arise apically in the papilla basilaris and are found near non-auditory (lagenar) fibres. Discharge rates to short tones were monotonically related to sound pressure level. Saturation rates often exceeded 300 spikes s-1. 'On-off' responses and primary suppression of spontaneous activity were observed. A direct comparison of spontaneous activity and tuning-curve symmetry revealed that, apart from quantitative differences, fundamental qualitative differences exist between starling and guinea-pig primary afferents.

  4. [Sphenopalatine ganglion block for postdural puncture headache in ambulatory setting].

    Science.gov (United States)

    Cardoso, José Miguel; Sá, Miguel; Graça, Rita; Reis, Hugo; Almeida, Liliana; Pinheiro, Célia; Machado, Duarte

    Postdural puncture headache (PDPH) is a common complication following subarachnoid blockade and its incidence varies with the size of the needle used and the needle design. Supportive therapy is the usual initial approach. Epidural blood patch (EBP) is the gold-standard when supportive therapy fails but has significant risks associated. Sphenopalatine ganglion block (SPGB) may be a safer alternative. We observed a 41 year-old female patient presenting with PDPH after a subarachnoid blockade a week before. We administrated 1l of crystalloids, Dexamethasone 4mg, parecoxib 40mg, acetaminophen 1g and caffeine 500mg without significant relief after 2hours. We performed a bilateral SPGB with a cotton-tipped applicator saturated with 0.5% Levobupivacaine under standard ASA monitoring. Symptoms relief was reported 5minutes after the block. The patient was monitored for an hour after which she was discharged and prescribed acetaminophen 1g and ibuprofen 400mg every 8hours for the following 2 days. She was contacted on the next day and again after a week reporting no pain in both situations. SPGB may attenuate cerebral vasodilation induced by parasympathetic stimulation transmitted through neurons that have synapses in the sphenopalatine ganglion. This would be in agreement with the Monro-Kellie concept and would explain why caffeine and sumatriptan can have some effect in the treatment of PDPH. Apparently, SPGB has a faster onset than EBP with better safety profile. We suggest that patients presenting with PDPH should be considered primarily for SPGB. Patients may have a rescue EBP if needed. Copyright © 2016 Sociedade Brasileira de Anestesiologia. Publicado por Elsevier Editora Ltda. All rights reserved.

  5. Sphenopalatine ganglion block for postdural puncture headache in ambulatory setting

    Directory of Open Access Journals (Sweden)

    José Miguel Cardoso

    Full Text Available Abstract Background and objectives: Postdural puncture headache (PDPH is a common complication following subarachnoid blockade and its incidence varies with the size of the needle used and the needle design. Suportive therapy is the usual initial approach. Epidural blood patch (EBP is the gold-standard when supportive therapy fails but has significant risks associated. Sphenopalatine ganglion block (SPGB may be a safer alternative. Case report: We observed a 41 year-old female patient presenting with PDPH after a subarachnoid blockade a week before. We administrated 1 l of crystalloids, Dexamethasone 4 mg, parecoxib 40 mg, acetaminophen 1 g and caffeine 500 mg without significant relief after 2 hours. We performed a bilateral SPGB with a cotton-tipped applicator saturated with 0.5% Levobupivacaine under standard ASA monitoring. Symptoms relief was reported 5 minutes after the block. The patient was monitored for an hour after which she was discharged and prescribed acetaminophen 1 g and ibuprofen 400 mg every 8 hours for the following 2 days. She was contacted on the next day and again after a week reporting no pain in both situation. Conclusions: SPGB may attenuate cerebral vasodilation induced by parasympathetic stimulation transmitted through neurons that have synapses in the sphenopalatine ganglion. This would be in agreement with the Monro-Kellie concept and would explain why caffeine and sumatriptan can have some effect in the treatment of PDPH. Apparently, SPGB has a faster onset than EBP with better safety profile. We suggest that patients presenting with PDPH should be considered primarily for SPGB. Patients may have a rescue EBP if needed.

  6. Light-induced fos expression in intrinsically photosensitive retinal ganglion cells in melanopsin knockout (opn4 mice.

    Directory of Open Access Journals (Sweden)

    Gary E Pickard

    Full Text Available Retinal ganglion cells that express the photopigment melanopsin are intrinsically photosensitive (ipRGCs and exhibit robust synaptically driven ON-responses to light, yet they will continue to depolarize in response to light when all synaptic input from rod and cone photoreceptors is removed. The light-evoked increase in firing of classical ganglion cells is determined by synaptic input from ON-bipolar cells in the proximal sublamina of the inner plexiform layer. OFF-bipolar cells synapse with ganglion cell dendrites in the distal sublamina of the inner plexiform layer. Of the several types of ipRGC that have been described, M1 ipRGCs send dendrites exclusively into the OFF region of the inner plexiform layer where they stratify near the border of the inner nuclear layer. We tested whether M1 ipRGCs with dendrites restricted to the OFF sublamina of the inner plexiform layer receive synaptic ON-bipolar input by examining light-induced gene expression in vivo using melanopsin knockout mice. Mice in which both copies of the melanopsin gene (opn4 have been replaced with the tau-lacZ gene (homozygous tau-lacZ(+/+ knockin mice are melanopsin knockouts (opn4(-/- but M1 ipRGCs are specifically identified by their expression of beta-galactosidase. Approximately 60% of M1 ipRGCs in Opn4(-/- mice exposed to 3 hrs of light expressed c-Fos; no beta-galactosidase-positive RGCs expressed c-Fos in the dark. Intraocular application of L-AP4, a compound which blocks transmission of visual signals between photoreceptors and ON-bipolar cells significantly reduced light-evoked c-Fos expression in M1 ipRGCs compared to saline injected eyes (66% saline vs 27% L-AP4. The results are the first description of a light-evoked response in an ipRGC lacking melanopsin and provide in vivo confirmation of previous in vitro observations illustrating an unusual circuit in the retina in which ganglion cells sending dendrites to the OFF sublamina of the inner plexiform layer

  7. Magnetic resonance imaging of intervertebral disc degeneration

    International Nuclear Information System (INIS)

    Maeda, Hiroshi; Noguchi, Masao; Kira, Hideaki; Fujiki, Hiroshi; Shimokawa, Isao; Hinoue, Kaichi.

    1993-01-01

    The aim of this study was to correlate the degree of lumbar intervertebral disc degeneration with findings of magnetic resonance imaging (MRI). Seventeen autopsied (from 7 patients) and 21 surgical (from 20 patients) intervertebral discs were used as specimens for histopathological examination. In addition, 21 intervertebral discs were examined on T2-weighted images. Histopathological findings from both autopsied and surgical specimens were well correlated with MRI findings. In particular, T2-weighted images reflected increased collagen fibers and rupture within the fibrous ring accurately. However, when severely degenerated intervertebral discs and hernia protruding the posterior longitudinal ligament existed, histological findings were not concordant well with T2-weighted images. Morphological appearances of autopsy specimens, divided into four on T2-weighted images, were well consistent with histological degeneration. This morphological classification, as shown on T2-weighted images, could also be used in the evaluation of intervertebral disc degeneration. (N.K.)

  8. Magnetic resonance imaging of intervertebral disc degeneration

    Energy Technology Data Exchange (ETDEWEB)

    Maeda, Hiroshi; Noguchi, Masao (Kitakyushu City Yahata Hospital, Fukuoka (Japan)); Kira, Hideaki; Fujiki, Hiroshi; Shimokawa, Isao; Hinoue, Kaichi

    1993-02-01

    The aim of this study was to correlate the degree of lumbar intervertebral disc degeneration with findings of magnetic resonance imaging (MRI). Seventeen autopsied (from 7 patients) and 21 surgical (from 20 patients) intervertebral discs were used as specimens for histopathological examination. In addition, 21 intervertebral discs were examined on T2-weighted images. Histopathological findings from both autopsied and surgical specimens were well correlated with MRI findings. In particular, T2-weighted images reflected increased collagen fibers and rupture within the fibrous ring accurately. However, when severely degenerated intervertebral discs and hernia protruding the posterior longitudinal ligament existed, histological findings were not concordant well with T2-weighted images. Morphological appearances of autopsy specimens, divided into four on T2-weighted images, were well consistent with histological degeneration. This morphological classification, as shown on T2-weighted images, could also be used in the evaluation of intervertebral disc degeneration. (N.K.).

  9. Assessment of Rod, Cone, and Intrinsically Photosensitive Retinal Ganglion Cell Contributions to the Canine Chromatic Pupillary Response

    Science.gov (United States)

    Yeh, Connie Y.; Koehl, Kristin L.; Harman, Christine D.; Iwabe, Simone; Guzman, José M.; Petersen-Jones, Simon M.; Kardon, Randy H.; Komáromy, András M.

    2017-01-01

    Purpose The purpose of this study was to evaluate a chromatic pupillometry protocol for specific functional assessment of rods, cones, and intrinsically photosensitive retinal ganglion cells (ipRGCs) in dogs. Methods Chromatic pupillometry was tested and compared in 37 dogs in different stages of primary loss of rod, cone, and combined rod/cone and optic nerve function, and in 5 wild-type (WT) dogs. Eyes were stimulated with 1-s flashes of dim (1 cd/m2) and bright (400 cd/m2) blue light (for scotopic conditions) or bright red (400 cd/m2) light with 25-cd/m2 blue background (for photopic conditions). Canine retinal melanopsin/Opn4 was cloned, and its expression was evaluated using real-time quantitative reverse transcription-PCR and immunohistochemistry. Results Mean ± SD percentage of pupil constriction amplitudes induced by scotopic dim blue (scDB), scotopic bright blue (scBB), and photopic bright red (phBR) lights in WT dogs were 21.3% ± 10.6%, 50.0% ± 17.5%, and 19.4% ± 7.4%, respectively. Melanopsin-mediated responses to scBB persisted for several minutes (7.7 ± 4.6 min) after stimulus offset. In dogs with inherited retinal degeneration, loss of rod function resulted in absent scDB responses, followed by decreased phBR responses with disease progression and loss of cone function. Primary loss of cone function abolished phBR responses but preserved those responses to blue light (scDB and scBB). Although melanopsin/Opn4 expression was diminished with retinal degeneration, melanopsin-expressing ipRGCs were identified for the first time in both WT and degenerated canine retinas. Conclusions Pupil responses elicited by light stimuli of different colors and intensities allowed differential functional assessment of canine rods, cones, and ipRGCs. Chromatic pupillometry offers an effective tool for diagnosing retinal and optic nerve diseases. PMID:28061512

  10. The effects of immune protein CD3ζ development and degeneration of retinal neurons after optic nerve injury.

    Directory of Open Access Journals (Sweden)

    Tao He

    Full Text Available Major histocompatibility complex (MHC class I molecules and their receptors play fundamental roles in neuronal death during diseases. T-cell receptors (TCR function as MHCI receptor on T-cells and both MHCI and a key component of TCR, CD3ζ, are expressed by mouse retinal ganglion cells (RGCs and displaced amacrine cells. Mutation of these molecules compromises the development of RGCs. We investigated whether CD3ζ regulates the development and degeneration of amacrine cells after RGC death. Surprisingly, mutation of CD3ζ not only impairs the proper development of amacrine cells expressing CD3ζ but also those not expressing CD3ζ. In contrast to effects of MHCI and its receptor, PirB, on other neurons, mutation of CD3ζ has no effect on RGC death and starburst amacrine cells degeneration after optic nerve crush. Thus, unlike MHCI and PirB, CD3ζ regulates the development of RGCs and amacrine cells but not their degeneration after optic nerve crush.

  11. Diffusion tensor imaging of nigral degeneration in Parkinson's disease: A region-of-interest and voxel-based study at 3 T and systematic review with meta-analysis.

    Science.gov (United States)

    Schwarz, Stefan T; Abaei, Maryam; Gontu, Vamsi; Morgan, Paul S; Bajaj, Nin; Auer, Dorothee P

    2013-01-01

    There is increasing interest in developing a reliable, affordable and accessible disease biomarker of Parkinson's disease (PD) to facilitate disease modifying PD-trials. Imaging biomarkers using magnetic resonance imaging (MRI) and diffusion tensor imaging (DTI) can describe parameters such as fractional anisotropy (FA), mean diffusivity (MD) or apparent diffusion coefficient (ADC). These parameters, when measured in the substantia nigra (SN), have not only shown promising but also varying and controversial results. To clarify the potential diagnostic value of nigral DTI in PD and its dependency on selection of region-of-interest, we undertook a high resolution DTI study at 3 T. 59 subjects (32 PD patients, 27 age and sex matched healthy controls) were analysed using manual outlining of SN and substructures, and voxel-based analysis (VBA). We also performed a systematic literature review and meta-analysis to estimate the effect size (DES) of disease related nigral DTI changes. We found a regional increase in nigral mean diffusivity in PD (mean ± SD, PD 0.80 ± 0.10 vs. controls 0.73 ± 0.06 · 10(- 3) mm(2)/s, p = 0.002), but no difference using a voxel based approach. No significant disease effect was seen using meta-analysis of nigral MD changes (10 studies, DES = + 0.26, p = 0.17, I(2) = 30%). None of the nigral regional or voxel based analyses of this study showed altered fractional anisotropy. Meta-analysis of 11 studies on nigral FA changes revealed a significant PD induced FA decrease. There was, however, a very large variation in results (I(2) = 86%) comparing all studies. After exclusion of five studies with unusual high values of nigral FA in the control group, an acceptable heterogeneity was reached, but there was non-significant disease effect (DES = - 0.5, p = 0.22, I(2) = 28%). The small PD related nigral MD changes in conjunction with the negative findings on VBA and meta-analysis limit the usefulness of nigral MD

  12. The nature of apraxia in corticobasal degeneration.

    OpenAIRE

    Leiguarda, R; Lees, A J; Merello, M; Starkstein, S; Marsden, C D

    1994-01-01

    Although apraxia is one of the most frequent signs in corticobasal degeneration, the phenomenology of this disorder has not been formally examined. Hence 10 patients with corticobasal degeneration were studied with a standardised evaluation for different types of apraxia. To minimise the confounding effects of the primary motor disorder, apraxia was assessed in the least affected limb. Whereas none of the patients showed buccofacial apraxia, seven showed deficits on tests of ideomotor apraxia...

  13. Myxomatous degeneration of the lumbar intervertebral disc.

    Science.gov (United States)

    Beatty, R A

    1985-08-01

    Sixteen patients were operated on for lumbar pain and pain radiating into the sciatic nerve distribution. In all 16, when the anulus fibrosus was incised, soft, gray disc material extruded under pressure like toothpaste being squeezed from a tube. This syndrome of myxomatous degeneration is a distinct entity, different from classical fibrotic disc degeneration or herniated nucleus pulposus. Surgical removal associated with partial facetectomy produced excellent results. The concept of incompetence of the anulus fibrosis is discussed.

  14. Hamiltonization of theories with degenerate coordinates

    International Nuclear Information System (INIS)

    Gitman, D.M.; Tyutin, I.V.

    2002-01-01

    We consider a class of Lagrangian theories where part of the coordinates does not have any time derivatives in the Lagrange function (we call such coordinates degenerate). We advocate that it is reasonable to reconsider the conventional definition of singularity based on the usual Hessian and, moreover, to simplify the conventional hamiltonization procedure. In particular, in such a procedure, it is not necessary to complete the degenerate coordinates with the corresponding conjugate momenta

  15. Chronic neurotrophin delivery promotes ectopic neurite growth from the spiral ganglion of deafened cochleae without compromising the spatial selectivity of cochlear implants.

    Science.gov (United States)

    Landry, Thomas G; Fallon, James B; Wise, Andrew K; Shepherd, Robert K

    2013-08-15

    Cochlear implants restore hearing cues in the severe-profoundly deaf by electrically stimulating spiral ganglion neurons (SGNs). However, SGNs degenerate following loss of cochlear hair cells, due at least in part to a reduction in the endogenous neurotrophin (NT) supply, normally provided by hair cells and supporting cells of the organ of Corti. Delivering exogenous NTs to the cochlea can rescue SGNs from degeneration and can also promote the ectopic growth of SGN neurites. This resprouting may disrupt the cochleotopic organization upon which cochlear implants rely to impart pitch cues. Using retrograde labeling and confocal imaging of SGNs, we determined the extent of neurite growth following 28 days of exogenous NT treatment in deafened guinea pigs with and without chronic electrical stimulation (ES). On completion of this treatment, we measured the spread of neural activation to intracochlear ES by recording neural responses across the cochleotopically organized inferior colliculus using multichannel recording techniques. Although NT treatment significantly increased both the length and the lateral extent of growth of neurites along the cochlea compared with deafened controls, these anatomical changes did not affect the spread of neural activation when examined immediately after 28 days of NT treatment. NT treatment did, however, result in lower excitation thresholds compared with deafened controls. These data support the application of NTs for improved clinical outcomes for cochlear implant patients. Copyright © 2013 Wiley Periodicals, Inc.

  16. The Relationship Between the Renin-Angiotensin-Aldosterone System and NMDA Receptor-Mediated Signal and the Prevention of Retinal Ganglion Cell Death.

    Science.gov (United States)

    Kobayashi, Mamoru; Hirooka, Kazuyuki; Ono, Aoi; Nakano, Yuki; Nishiyama, Akira; Tsujikawa, Akitaka

    2017-03-01

    Excitotoxicity, which is due to glutamate-induced toxic effects on the retinal ganglion cell (RGC), is one of several mechanisms of RGC loss. The renin-angiotensin-aldosterone system (RAAS) has also been implicated in RGC death. Therefore, it is important to determine the exact relationship between the RAAS and N-methyl-d-aspartate (NMDA) receptor-mediated signal in order to prevent RGC death. N-methyl-d-aspartate or aldosterone was injected into the vitreous body. After intravitreal injection of NMDA or aldosterone, animals were treated with spironolactone or memantine. Retinal damage was evaluated by measuring the number of RGCs at 4 weeks after local administration of aldosterone or at 2 weeks after local administration of NMDA. Vitreous humor levels of aldosterone were measured using enzyme immunoassay kits. A significantly decreased number of RGCs were observed after intravitreal injection of NMDA. Although spironolactone did not show any neuroprotective effects, memantine significantly reduced NMDA-induced degeneration in the retina. Furthermore, a significant decrease in the number of RGCs was observed after an intravitreal injection of aldosterone. While memantine did not exhibit any neuroprotective effects, spironolactone caused a significant reduction in the aldosterone-induced degeneration in the retina. There was no change in the aldosterone concentration in the vitreous humor after an NMDA injection. Our findings indirectly show that there is no relationship between the RAAS and NMDA receptor-mediated signal with regard to RGC death.

  17. Hydrostatic pressure does not cause detectable changes in survival of human retinal ganglion cells.

    Directory of Open Access Journals (Sweden)

    Andrew Osborne

    Full Text Available PURPOSE: Elevated intraocular pressure (IOP is a major risk factor for glaucoma. One consequence of raised IOP is that ocular tissues are subjected to increased hydrostatic pressure (HP. The effect of raised HP on stress pathway signaling and retinal ganglion cell (RGC survival in the human retina was investigated. METHODS: A chamber was designed to expose cells to increased HP (constant and fluctuating. Accurate pressure control (10-100 mmHg was achieved using mass flow controllers. Human organotypic retinal cultures (HORCs from donor eyes (<24 h post mortem were cultured in serum-free DMEM/HamF12. Increased HP was compared to simulated ischemia (oxygen glucose deprivation, OGD. Cell death and apoptosis were measured by LDH and TUNEL assays, RGC marker expression by qRT-PCR (THY-1 and RGC number by immunohistochemistry (NeuN. Activated p38 and JNK were detected by Western blot. RESULTS: Exposure of HORCs to constant (60 mmHg or fluctuating (10-100 mmHg; 1 cycle/min pressure for 24 or 48 h caused no loss of structural integrity, LDH release, decrease in RGC marker expression (THY-1 or loss of RGCs compared with controls. In addition, there was no increase in TUNEL-positive NeuN-labelled cells at either time-point indicating no increase in apoptosis of RGCs. OGD increased apoptosis, reduced RGC marker expression and RGC number and caused elevated LDH release at 24 h. p38 and JNK phosphorylation remained unchanged in HORCs exposed to fluctuating pressure (10-100 mmHg; 1 cycle/min for 15, 30, 60 and 90 min durations, whereas OGD (3 h increased activation of p38 and JNK, remaining elevated for 90 min post-OGD. CONCLUSIONS: Directly applied HP had no detectable impact on RGC survival and stress-signalling in HORCs. Simulated ischemia, however, activated stress pathways and caused RGC death. These results show that direct HP does not cause degeneration of RGCs in the ex vivo human retina.

  18. Ganglionated plexi stimulation induces pulmonary vein triggers and promotes atrial arrhythmogenecity: In silico modeling study.

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    Minki Hwang

    Full Text Available The role of the autonomic nervous system (ANS on atrial fibrillation (AF is difficult to demonstrate in the intact human left atrium (LA due to technical limitations of the current electrophysiological mapping technique. We examined the effects of the ANS on the initiation and maintenance of AF by employing a realistic in silico human left atrium (LA model integrated with a model of ganglionated plexi (GPs.We incorporated the morphology of the GP and parasympathetic nerves in a three-dimensional (3D realistic LA model. For the model of ionic currents, we used a human atrial model. GPs were stimulated by increasing the IK[ACh], and sympathetic nerve stimulation was conducted through a homogeneous increase in the ICa-L. ANS-induced wave-dynamics changes were evaluated in a model that integrated a patient's LA geometry, and we repeated simulation studies using LA geometries from 10 different patients.The two-dimensional model of pulmonary vein (PV cells exhibited late phase 3 early afterdepolarization-like activity under 0.05μM acetylcholine (ACh stimulation. In the 3D simulation model, PV tachycardia was induced, which degenerated to AF via GP (0.05μM ACh and sympathetic (7.0×ICa-L stimulations. Under sustained AF, local reentries were observed at the LA-PV junction. We also observed that GP stimulation reduced the complex fractionated atrial electrogram (CFAE-cycle length (CL, p<0.01 and the life span of phase singularities (p<0.01. GP stimulation also increased the overlap area of the GP and CFAE areas (CFAE-CL≤120ms, p<0.01. When 3 patterns of virtual ablations were applied to the 3D AF models, circumferential PV isolation including the GP was the most effective in terminating AF.Cardiac ANS stimulations demonstrated triggered activity, automaticity, and local reentries at the LA-PV junction, as well as co-localized GP and CFAE areas in the 3D in silico GP model of the LA.

  19. Efficacy of stellate ganglion block with an adjuvant ketamine for peripheral vascular disease of the upper limbs

    Directory of Open Access Journals (Sweden)

    Kalpana R Kulkarni

    2010-01-01

    Full Text Available Stellate ganglion block (STGB is commonly indicated in painful conditions like reflex sympathetic dystrophy, malignancies of head and neck, Reynaud′s disease and vascular insufficiency of the upper limbs. The sympathetic blockade helps to relieve pain and ischaemia. Diagnostic STGB is usually performed with local anaesthetics followed by therapeutic blockade with steroids, neurolytic agents or radiofrequency ablation of ganglion. There is increasing popularity and evidence for the use of adjuvants like opioid, clonidine and N Methyl d Aspartate (NMDA receptor antagonist - ketamine - for the regional and neuroaxial blocks. The action of ketamine with sympatholytic block is through blockade of peripherally located NMDA receptors that are the target in the management of neuropathic pain, with the added benefit of counteracting the "wind-up" phenomena of chronic pain. We studied ketamine as an adjuvant to the local anaesthetic for STGB in 20 cases of peripheral vascular disease of upper limbs during the last 5 years at our institution. STGB was given for 2 days with 2 ml of 2% lignocaine + 8 ml of 0.25% bupivacaine, followed by block with the addition of 0.5 mg/kg of ketamine for three consecutive days. There was significant pain relief of longer duration with significant rise in hand temperature. We also observed complete healing of the gangrenous fingers in 17/19 patients.

  20. Dynamic expression pattern of Sonic hedgehog in developing cochlear spiral ganglion neurons.

    Science.gov (United States)

    Liu, Zhiyong; Owen, Thomas; Zhang, Lingli; Zuo, Jian

    2010-06-01

    Sonic hedgehog (Shh) signaling plays important roles in the formation of the auditory epithelium. However, little is known about the detailed expression pattern of Shh and the cell sources from which Shh is secreted. By analyzing Shh(CreEGFP/+) mice, we found that Shh was first expressed in all cochlear spiral ganglion neurons by embryonic day 13.5, after which its expression gradually decreased from base to apex. By postnatal day 0, it was not detected in any spiral ganglion neurons. Genetic cell fate mapping results also confirmed that Shh was exclusively expressed in all spiral ganglion neurons and not in surrounding glia cells. The basal-to-apical wave of Shh decline strongly resembles that of hair cell differentiation, supporting the idea that Shh signaling inhibits hair cell differentiation. Furthermore, this Shh(CreEGFP/+) mouse is a useful Cre line in which to delete floxed genes specifically in spiral ganglion neurons of the developing cochlea.

  1. A Guyon's canal ganglion presenting as occupational overuse syndrome: A case report.

    LENUS (Irish Health Repository)

    Chan, Jeffrey C Y

    2008-01-01

    Occupational overuse syndrome (OOS) can present as Guyon\\'s canal syndrome in computer keyboard users. We report a case of Guyon\\'s canal syndrome caused by a ganglion in a computer user that was misdiagnosed as OOS.

  2. Cortical Proteins are Chemokinetic to Cells from the Medial Ganglionic Eminence

    Science.gov (United States)

    2011-05-28

    Neuroscience Program Director During embryonic development, a majority of neocortical interneurons originate from the medial ganglionic eminence (MGE...day vaginal plug is seen) EGF Epidermal growth factor ErbB EGF receptor GABA Gamma-aminobutyric acid GE Ganglionic eminence HGF Hepatocyte...species, all mammals have GABAergic precursors residing in the GE producing neurons that migrate along the same tangential route to the neocortex

  3. Overexpression of Pax6 results in microphthalmia, retinal dysplasia and defective retinal ganglion cell axon guidance

    Directory of Open Access Journals (Sweden)

    Jeffery Glen

    2008-05-01

    Full Text Available Abstract Background The transcription factor Pax6 is expressed by many cell types in the developing eye. Eyes do not form in homozygous loss-of-function mouse mutants (Pax6Sey/Sey and are abnormally small in Pax6Sey/+ mutants. Eyes are also abnormally small in PAX77 mice expressing multiple copies of human PAX6 in addition to endogenous Pax6; protein sequences are identical in the two species. The developmental events that lead to microphthalmia in PAX77 mice are not well-characterised, so it is not clear whether over- and under-expression of Pax6/PAX6 cause microphthalmia through similar mechanisms. Here, we examined the consequences of over-expression for the eye and its axonal connections. Results Eyes form in PAX77+/+ embryos but subsequently degenerate. At E12.5, we found no abnormalities in ocular morphology, retinal cell cycle parameters and the incidence of retinal cell death. From E14.5 on, we observed malformations of the optic disc. From E16.5 into postnatal life there is progressively more severe retinal dysplasia and microphthalmia. Analyses of patterns of gene expression indicated that PAX77+/+ retinae produce a normal range of cell types, including retinal ganglion cells (RGCs. At E14.5 and E16.5, quantitative RT-PCR with probes for a range of molecules associated with retinal development showed only one significant change: a slight reduction in levels of mRNA encoding the secreted morphogen Shh at E16.5. At E16.5, tract-tracing with carbocyanine dyes in PAX77+/+ embryos revealed errors in intraretinal navigation by RGC axons, a decrease in the number of RGC axons reaching the thalamus and an increase in the proportion of ipsilateral projections among those RGC axons that do reach the thalamus. A survey of embryos with different Pax6/PAX6 gene dosage (Pax6Sey/+, Pax6+/+, PAX77+ and PAX77+/+ showed that (1 the total number of RGC axons projected by the retina and (2 the proportions that are sorted into the ipsilateral and

  4. Progressive neuronal degeneration of childhood with liver disease

    International Nuclear Information System (INIS)

    Kendall, B.E.; Boyd, S.G.; Egger, J.; Harding, B.N.

    1987-01-01

    The clinical, electrophysiological and neuroradiological features of thirteen patients suffering from progressive neuronal degeneration of childhood with liver failure are presented. The disease commonly presents very early in life with progressive mental retardation, followed by intractable epilepsy, and should be suspected clinically especially if there is a family history of similar disorder in a sibling. On computed tomography there are low density regions, particularly in the occipital and posterior temporal lobes, involving both cortex and white matter, combined with or followed by progressive atrophy. Typical EEG findings may be confirmatory. (orig.)

  5. Etanercept, a widely used inhibitor of tumor necrosis factor-α (TNF-α, prevents retinal ganglion cell loss in a rat model of glaucoma.

    Directory of Open Access Journals (Sweden)

    Miin Roh

    Full Text Available Visual loss in glaucoma is associated with pathological changes in retinal ganglion cell (RGC axons and a slow decline in the RGC population. Age and elevated intraocular pressure (IOP are the main risk factors for glaucomatous loss of vision. Several studies have implicated the proinflammatory cytokine tumor necrosis factor-α (TNF-α as a link between elevated IOP and RGC death, but the cellular source of TNF-α and its causative role in RGC death remain uncertain. Here, using a rat model of glaucoma, we investigated the source of elevated TNF-α and examined whether Etanercept, a TNF-α blocker that is in common clinical use for other indications, is protective against RGC death.Episcleral vein cauterization (EVC caused intraocular pressure (IOP to be elevated for at least 28 days. IOP elevation resulted in a dramatic increase in TNF-α levels within a few days, axonal degeneration, and a 38% loss of RGCs by 4 weeks. Immunostaining coupled with confocal microscopy showed that OHT induced robust induction of TNF-α in Iba-1-positive microglia around the optic nerve head (ONH. Despite persistent elevation of IOP, Etanercept reduced microglial activation, TNF-α levels, axon degeneration in the optic nerve, and the loss of RGCs.Ocular hypertension (OHT triggers an inflammatory response characterized by the appearance of activated microglia around the ONH that express TNF-α. Blocking TNF-α activity with a clinically approved agent inhibits this microglial response and prevents axonal degeneration and loss of RGCs. These findings suggest a new treatment strategy for glaucoma using TNF-α antagonists or suppressors of inflammation.

  6. Spontaneous activity in the statoacoustic ganglion of the chicken embryo.

    Science.gov (United States)

    Jones, T A; Jones, S M

    2000-03-01

    Statoacoustic ganglion cells in the mature bird include neurons that are responsive to sound (auditory) and those that are not (nonauditory). Those that are nonauditory have been shown to innervate an otolith organ, the macula lagena, whereas auditory neurons innervate the basilar papilla. In the present study, single-unit recordings of statoacoustic ganglion cells were made in embryonic (E19, mean = 19.2 days of incubation) and hatchling (P6-P14, mean = 8.6 days posthatch) chickens. Spontaneous activity from the two age groups was compared with developmental changes. Activity was evaluated for 47 auditory, 11 nonauditory, and 6 undefined eighth nerve neurons in embryos and 29 auditory, 26 nonauditory, and 1 undefined neurons in hatchlings. For auditory neurons, spontaneous activity displayed an irregular pattern [discharge interval coefficient of variation (CV) was >0.5, mean CV for embryos was 1.46 +/- 0.58 and for hatchlings was 1.02 +/- 0.25; means +/- SD]. Embryonic discharge rates ranged from 0.05 to 97.6 spikes per second (sp/s) for all neurons (mean 18.6 +/- 16.9 sp/s). Hatchling spontaneous rates ranged from 1.2 to 185.2 sp/s (mean 66.5 +/- 39.6 sp/s). Discharge rates were significantly higher for hatchlings (P embryonic auditory neurons displayed long silent periods between irregular bursts of neural activity, a feature not seen posthatch. All regular bursting discharge patterns were correlated with heart rate in both embryos and hatchlings. Preferred intervals were visible in the time interval histograms (TIHs) of only one embryonic neuron in contrast to 55% of the neurons in posthatch animals. Generally, the embryonic auditory TIH displayed a modified quasi-Poisson distribution. Nonauditory units generally displayed regular (CV 0.5) activity and Gaussian and modified-Gaussian TIHs. Long silent periods or bursting patterns were not a characteristic of embryonic nonauditory neurons. CV varied systematically as a function of discharge rate in nonauditory

  7. The brain basis of musicophilia: evidence from frontotemporal lobar degeneration

    Directory of Open Access Journals (Sweden)

    Phillip David Fletcher

    2013-06-01

    Full Text Available Musicophilia, or abnormal craving for music, is a poorly understood phenomenon that has been associated in particular with focal degeneration of the temporal lobes. Here we addressed the brain basis of musicophilia using voxel-based morphometry (VBM on MR volumetric brain images in a retrospectively ascertained cohort of patients meeting clinical consensus criteria for frontotemporal lobar degeneration: of 37 cases ascertained, 12 had musicophilia and 25 did not exhibit the phenomenon. The syndrome of semantic dementia was relatively over-represented among the musicophilic subgroup. A VBM analysis revealed significantly increased regional grey matter volume in left posterior hippocampus in the musicophilic subgroup relative to the non-musicophilic group (p<0.05 corrected for regional comparisons; at a relaxed significance threshold (P<0.001 uncorrected across the brain volume musicophilia was associated with additional relative sparing of regional grey matter in other temporal lobe and prefrontal areas and atrophy of grey matter in posterior parietal and orbitofrontal areas. The present findings suggest a candidate brain substrate for musicophilia as a signature of distributed network damage that may reflect a shift of hedonic processing toward more abstract (non-social stimuli, with some specificity for particular neurodegenerative pathologies.

  8. Spatially divergent cardiac responses to nicotinic stimulation of ganglionated plexus neurons in the canine heart.

    Science.gov (United States)

    Cardinal, René; Pagé, Pierre; Vermeulen, Michel; Ardell, Jeffrey L; Armour, J Andrew

    2009-01-28

    Ganglionated plexuses (GPs) are major constituents of the intrinsic cardiac nervous system, the final common integrator of regional cardiac control. We hypothesized that nicotinic stimulation of individual GPs exerts divergent regional influences, affecting atrial as well as ventricular functions. In 22 anesthetized canines, unipolar electrograms were recorded from 127 atrial and 127 ventricular epicardial loci during nicotine injection (100 mcg in 0.1 ml) into either the 1) right atrial (RA), 2) dorsal atrial, 3) left atrial, 4) inferior vena cava-inferior left atrial, 5) right ventricular, 6) ventral septal ventricular or 7) cranial medial ventricular (CMV) GP. In addition to sinus and AV nodal function, neural effects on atrial and ventricular repolarization were identified as changes in the area subtended by unipolar recordings under basal conditions and at maximum neurally-induced effects. Animals were studied with intact AV node or following ablation to achieve ventricular rate control. Atrial rate was affected in response to stimulation of all 7 GPs with an incidence of 50-95% of the animals among the different GPs. AV conduction was affected following stimulation of 6/7 GP with an incidence of 22-75% among GPs. Atrial and ventricular repolarization properties were affected by atrial as well as ventricular GP stimulation. Distinct regional patterns of repolarization changes were identified in response to stimulation of individual GPs. RAGP predominantly affected the RA and posterior right ventricular walls whereas CMVGP elicited biatrial and biventricular repolarization changes. Spatially divergent and overlapping cardiac regions are affected in response to nicotinic stimulation of neurons in individual GPs.

  9. Crocetin prevents retinal degeneration induced by oxidative and endoplasmic reticulum stresses via inhibition of caspase activity.

    Science.gov (United States)

    Yamauchi, Mika; Tsuruma, Kazuhiro; Imai, Shunsuke; Nakanishi, Tomohiro; Umigai, Naofumi; Shimazawa, Masamitsu; Hara, Hideaki

    2011-01-10

    Crocetin is a carotenoid that is the aglicone of crocin, which are found in saffron stigmas (Crocus sativus L.) and gardenia fruit (Gardenia jasminoides Ellis). In this study, we investigated the effects of crocetin on retinal damage. To examine whether crocetin affects stress pathways, we investigated intracellular oxidation induced by reactive oxygen species, expression of endoplasmic reticulum (ER) stress-related proteins, disruption of the mitochondrial membrane potential (ΔΨ(m)), and caspases activation. In vitro, we employed cultured retinal ganglion cells (RGC-5, a mouse ganglion cell-line transformed using E1A virus). Cell damage was induced by tunicamycin or hydrogen peroxide (H(2)O(2)) exposure. Crocetin at a concentration of 3μM showed the inhibitory effect of 50-60% against tunicamycin- and H(2)O(2)-induced cell death and inhibited increase in caspase-3 and -9 activity. Moreover, crocetin inhibited the enzymatic activity of caspase-9 in a cell-free system. In vivo, retinal damage in mice was induced by exposure to white light at 8000lx for 3h after dark adaptation. Photoreceptor damage was evaluated by measuring the outer nuclear layer thickness at 5days after light exposure and recording the electroretinogram (ERG). Retinal cell damage was also detected with Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining at 48h after light exposure. Crocetin at 100mg/kg, p.o. significantly inhibited photoreceptor degeneration and retinal dysfunction and halved the expression of TUNEL-positive cells. These results indicate that crocetin has protective effects against retinal damage in vitro and in vivo, suggesting that the mechanism may inhibit increase in caspase-3 and -9 activities after retinal damage. Copyright © 2010 Elsevier B.V. All rights reserved.

  10. Inner nuclear layer thickening is inversley proportional to retinal ganglion cell loss in optic neuritis.

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    Megha Kaushik

    Full Text Available AIM: To examine the relationship between retinal ganglion cell loss and changes in the inner nuclear layer (INL in optic neuritis (ON. METHODS: 36 multiple sclerosis (MS patients with a history of ON and 36 age and sex-matched controls underwent Optical Coherence Tomography. The paramacular retinal nerve fiber layer (RNFL, combined ganglion cell and inner plexiform layers (GCL/IPL and inner nuclear layer (INL thickness were measured at 36 points around the fovea. To remove inter-subject variability, the difference in thickness of each layer between the ON and fellow eye of each patient was calculated. A topographic analysis was conducted. RESULTS: The INL of the ON patients was thicker than the controls (42.9µm versus 39.6µm, p=0.002. ON patients also had a thinner RNFL (27.8µm versus 32.2µm, p<0.001 and GCL/IPL (69.3µm versus 98.1µm, p<0.001. Among the controls, there was no correlation between RNFL and GCL/IPL as well as RNFL and INL, but a positive correlation was seen between GCL/IPL and INL (r=0.65, p<0.001. In the ON group, there was a positive correlation between RNFL and GCL/IPL (r=0.80, p<0.001 but a negative correlation between RNFL and INL (r=-0.61, p<0.001 as well as GCL/IPL and INL (r=-0.44, p=0.007. The negative correlation between GCL/IPL and INL strengthened in the ON group when inter-subject variability was removed (r=-0.75, p<0.001. Microcysts within the INL were present in 5 ON patients, mainly in the superior and infero-nasal paramacular regions. While patients with microcysts lay at the far end of the correlation curve between GCL/IPL and INL (i.e. larger INL and smaller GCL/IPL compared to other patients, their exclusion did not affect the correlation (r= -0.76, p<0.001. CONCLUSIONS: INL enlargement in MS-related ON is associated with the severity of GCL loss. This is a continuous relationship and patients with INL microcysts may represent the extreme end of the scale.

  11. Dendritic relationship between starburst amacrine cells and direction-selective ganglion cells in the rabbit retina.

    Science.gov (United States)

    Dong, Wei; Sun, Wenzhi; Zhang, Yingye; Chen, Xiaorong; He, Shigang

    2004-04-01

    We investigated the dendritic relationship between starburst amacrine cells (SAs) and morphologically and physiologically characterized ON and ON-OFF direction-selective ganglion cells (DSGCs) in the rabbit retina. ON and ON-OFF DSGCs were found to exhibit tight dendritic cofasciculation with the SA plexus, visualized by immunolabelling of the vesicular acetylcholine transporter (VAChT). The degree of cofasciculation of both types of DSGC dendrites and SA plexus was found to be significant, unlike the relationship between non-DS cells and the SA plexus, which was close to chance distribution. No difference in the degree of cofasciculation in different regions of the DS dendritic field was observed. Individual SAs intracellularly injected both on the 'preferred' and 'null' side of the DSGCs showed the same degree of cofasciculation with the DSGCs. Therefore, the computation of motion direction is unlikely to result from apparent asymmetry in geometric proximity between SAs and DSGCs. Highly selective synaptic connections between SAs and DSGCs are necessary.

  12. Electrical activity of ON and OFF retinal ganglion cells: a modelling study

    Science.gov (United States)

    Guo, Tianruo; Tsai, David; Morley, John W.; Suaning, Gregg J.; Kameneva, Tatiana; Lovell, Nigel H.; Dokos, Socrates

    2016-04-01

    Objective. Retinal ganglion cells (RGCs) demonstrate a large range of variation in their ionic channel properties and morphologies. Cell-specific properties are responsible for the unique way RGCs process synaptic inputs, as well as artificial electrical signals such as that from a visual prosthesis. A cell-specific computational modelling approach allows us to examine the functional significance of regional membrane channel expression and cell morphology. Approach. In this study, an existing RGC ionic model was extended by including a hyperpolarization activated non-selective cationic current as well as a T-type calcium current identified in recent experimental findings. Biophysically-defined model parameters were simultaneously optimized against multiple experimental recordings from ON and OFF RGCs. Main results. With well-defined cell-specific model parameters and the incorporation of detailed cell morphologies, these models were able to closely reconstruct and predict ON and OFF RGC response properties recorded experimentally. Significance. The resulting models were used to study the contribution of different ion channel properties and spatial structure of neurons to RGC activation. The techniques of this study are generally applicable to other excitable cell models, increasing the utility of theoretical models in accurately predicting the response of real biological neurons.

  13. Chemo- and thermosensory responsiveness of Grueneberg ganglion neurons relies on cyclic guanosine monophosphate signaling elements.

    Science.gov (United States)

    Mamasuew, Katharina; Hofmann, Nina; Kretzschmann, Verena; Biel, Martin; Yang, Ruey-Bing; Breer, Heinz; Fleischer, Joerg

    2011-01-01

    Neurons of the Grueneberg ganglion (GG) in the anterior nasal region of mouse pups respond to cool temperatures and to a small set of odorants. While the thermosensory reactivity appears to be mediated by elements of a cyclic guanosine monophosphate (cGMP) cascade, the molecular mechanisms underlying the odor-induced responses are unclear. Since odor-responsive GG cells are endowed with elements of a cGMP pathway, specifically the transmembrane guanylyl cyclase subtype GC-G and the cyclic nucleotide-gated ion channel CNGA3, the possibility was explored whether these cGMP signaling elements may also be involved in chemosensory GG responses. Experiments with transgenic mice deficient for GC-G or CNGA3 revealed that GG responsiveness to given odorants was significantly diminished in these knockout animals. These findings suggest that a cGMP cascade may be important for both olfactory and thermosensory signaling in the GG. However, in contrast to the thermosensory reactivity, which did not decline over time, the chemosensory response underwent adaptation upon extended stimulation, suggesting that the two transduction processes only partially overlap. Copyright © 2011 S. Karger AG, Basel.

  14. Anatomy of Meckel's cave and the trigeminal ganglion: anatomical landmarks for a safer approach to them.

    Science.gov (United States)

    Arslan, Mehmet; Deda, Haluk; Avci, Emel; Elhan, Alaittin; Tekdemir, Ibrahim; Tubbs, R Shane; Silav, Gokalp; Yilmaz, Erdal; Baskaya, Mustafa Kemal

    2012-01-01

    Surgical approaches to Meckel's cave (MC) are often technically difficult and sometimes associated with postoperative morbidity. The relationship of surgical landmarks to relevant anatomy is important. Therefore, we attempted to delineate quantitatively their anatomy and the relationships between MC and surrounding structures. With the aid of a surgical microscope, MC and its contents were studied in 15 formalin-fixed cadaver head specimens. Measurements were made and their relationships were observed. The distance from the zygomatic arch and the lateral end of the petrous ridge to MC was 26.5 and 34.4 mm, respectively. The distance from the arcuate eminence, the facial nerve hiatus, and the foramen spinosum to MC was 16.6, 12.8 and 7.46 mm respectively. The TG lay 5.81 mm posterior to the foramen ovale. The distance from the abducens, trochlear and oculomotor nerves to the trigeminal ganglion was 1.87, 5.53 and 6.57 mm respectively. The distance from the posterior and the anterior walls of the sigmoid sinus to the trigeminal porus was 43.6 and 33.1 mm respectively. The trigeminal porus was on average 7.19 mm from the anterior wall of the internal acoustic meatus. The anatomical landmarks as presented herein regarding MC may be used for a safer skull base approach to the region.

  15. Anatomical study and clinical significance of the rami communicantes between cervicothoracic ganglion and brachial plexus.

    Science.gov (United States)

    Song, Zhan-Feng; Sun, Mao-Min; Wu, Zhan-Yong; Xia, Chun-Lin

    2010-10-01

    The aim of this study was to provide a detailed characterization of the rami communicantes between the stellate (or cervicothoraic) ganglion (CTG) and brachial plexus (BP). Rami communicantes of 33 fixed adult cadavers were macroscopically observed, and connection between CTG and spinal nerves and branching was investigated. In all cases, except one, the hibateral medial rami communicantes was found to be positioned symmetrically between the CTG and C7, C8 spinal nerves. Gray rami communicantes arising from the CTG joined C8, C7, C6 nerve roots on 66, 63, and 6 sides, respectively, and branched from the rami communicantes to C7, C6, C5 nerve roots lying on 51, 41, and 2 sides, respectively. Forty-five sides of the branches from rami communicantes derived from CTG to C8 were observed to ascend through the transverse foramina of the C7 nerve. The branches from rami communicantes derived from CTG to C7 to the C6 nerve were observed ascending through the foramen transversarium of the six cervical vertebrae along with the vertebral artery and joining the C6 spinal nerve in 41 sides. Knowledge about the general distribution and individual variations of the rami communicantes between CTG and BP will be useful toward studies involving the inference of sympathetic nerve stimulation of the upper limbs and could be important for surgeons who perform surgical procedures in the cervical region or medical blockade of nerve fibers. Copyright © 2010 Wiley-Liss, Inc.

  16. Changes in number of water-filled vesicles of choroid plexus in early and late phase of experimental rabbit subarachnoid hemorrhage model: the role of petrous ganglion of glossopharyngeal nerve.

    Science.gov (United States)

    Aydin, Mehmet Dumlu; Kanat, Ayhan; Turkmenoglu, Osman Nuri; Yolas, Coskun; Gundogdu, Cemal; Aydın, Nazan

    2014-07-01

    Cerebrospinal fluid (CSF) secretion may be increased in the early phases of subarachnoid hemorrhage (SAH), possibly via ischemic glossopharyngeal nerve discharges, and decreased due to glossopharyngeal nerve degeneration in the late phase of SAH; but this reflex pathway has not been definitively investigated. We studied the relationship between petrous ganglion of the glossopharyngeal nerve (GPN) and water vesicles of the choroid plexus (CP) in the early and late phases of SAH. This study was conducted on 30 rabbits, divided into four groups, with five rabbits in the control group (group I), five rabbits in the sham group (Group II), and 20 rabbits in the SAH group. In the SAH group, five of the animals were decapitated after 4 days of cisternal blood injections (Group III), and the other 15 animals were decapitated after 20 days of injections (Group IV). The Petrous Ganglia and CPs of lateral ventricles were removed and stained for stereological analysis. The mean number of follicles per cubic millimeter was 5.3 ± 1.2 the in control group (Group I), 4.5 ± 0.9 in the sham group (Group II), 16.60 ± 3.77 the in early decapitated group (Group III), and 4.30 ± 0.84 in the late decapitated group (Group IV). The mean number of degenerated neuron density of petrous ganglions was 6 ± 2, 50 ± 6, 742 ± 96, and 2.420 ± 350 in the control (Group I), sham (Group II), early decapitated (Group III), and late decapitated group (Group IV), respectively. The mean number of water vesicles was statistically different after SAH between the early decapitated group (group III) and the late decapitated group (group IV) (P ganglion cells of the GPN and water vesicles of CP in the early and late phases of SAH, and found that CP vesicles are increased in the early phase of SAH due to irritation of GPN, and decreased in the late phase due to ischemic insult of the petrous ganglion and parasympathetic innervation of the CP.

  17. Characteristics of sodium currents in rat geniculate ganglion neurons.

    Science.gov (United States)

    Nakamura, Shiro; Bradley, Robert M

    2011-12-01

    Geniculate ganglion (GG) cell bodies of chorda tympani (CT), greater superficial petrosal (GSP), and posterior auricular (PA) nerves transmit orofacial sensory information to the rostral nucleus of the solitary tract. We have used whole cell recording to investigate the characteristics of the Na(+) channels in isolated Fluorogold-labeled GG neurons that innervate different peripheral receptive fields. GG neurons expressed two classes of Na(+) channels, TTX sensitive (TTX-S) and TTX resistant (TTX-R). The majority of GG neurons expressed TTX-R currents of different amplitudes. TTX-R currents were relatively small in 60% of the neurons but were large in 12% of the sampled population. In a further 28% of the neurons, TTX completely abolished all Na(+) currents. Application of TTX completely inhibited action potential generation in all CT and PA neurons but had little effect on the generation of action potentials in 40% of GSP neurons. Most CT, GSP, and PA neurons stained positively with IB(4), and 27% of the GSP neurons were capsaicin sensitive. The majority of IB(4)-positive GSP neurons with large TTX-R Na(+) currents responded to capsaicin, whereas IB(4)-positive GSP neurons with small TTX-R Na(+) currents were capsaicin insensitive. These data demonstrate the heterogeneity of GG neurons and indicate the existence of a subset of GSP neurons sensitive to capsaicin, usually associated with nociceptors. Since there are no reports of nociceptors in the GSP receptive field, the role of these capsaicin-sensitive neurons is not clear.

  18. [Peripheral retinal degenerations--treatment recommendations].

    Science.gov (United States)

    Joussen, A M; Kirchhof, B

    2004-10-01

    This report reviews the clinical appearance of degenerative diseases of the peripheral retina in relationship to the risk of developing a rhegmatogenous retinal detachment. We present recommendations for preventive treatment in eyes at increased risk of developing retinal detachment. Retinal degenerations are common lesions involving the peripheral retina but most of them are clinically insignificant. Lattice degeneration, degenerative retinoschisis, cystic retinal tufts, and very rarely zonular traction tufts can result in rhegmatogenous retinal detachment. Therefore, these lesions have been considered for prophylactic treatment; however, adequate studies have not been performed to date. Most of the peripheral retinal degenerations may not require treatment except in rare, high-risk situations. According to current knowledge there is no higher incidence of secondary pucker or other side effects after laser coagulation. Therefore, generous laser indication is recommended if risk factors apply.

  19. Families and degenerations of conformal field theories

    Energy Technology Data Exchange (ETDEWEB)

    Roggenkamp, D.

    2004-09-01

    In this work, moduli spaces of conformal field theories are investigated. In the first part, moduli spaces corresponding to current-current deformation of conformal field theories are constructed explicitly. For WZW models, they are described in detail, and sigma model realizations of the deformed WZW models are presented. The second part is devoted to the study of boundaries of moduli spaces of conformal field theories. For this purpose a notion of convergence of families of conformal field theories is introduced, which admits certain degenerated conformal field theories to occur as limits. To such a degeneration of conformal field theories, a degeneration of metric spaces together with additional geometric structures can be associated, which give rise to a geometric interpretation. Boundaries of moduli spaces of toroidal conformal field theories, orbifolds thereof and WZW models are analyzed. Furthermore, also the limit of the discrete family of Virasoro minimal models is investigated. (orig.)

  20. Intramuscular degeneration process in Duchenne muscular dystrophy

    International Nuclear Information System (INIS)

    Hasegawa, Takeshi; Matsumra, Kiichiro; Hashimoto, Takahiro; Ikehira, Hiroo; Fukuda, Hiroshi; Tateno, Yukio.

    1992-01-01

    Intramuscular degeneration process of Duchenne dystrophy skeletal muscles was investigated by longitudinal skeletal muscle imaging with high-field-strength NMR-CT of 1.5 Tesla. Thigh muscles in 10 cases ranging in age from 4 to 19 years were examined by T 1 -weighted longitudinal images (TR=215∼505 ms, TE=19∼20 ms). The following results were obtained. Skeletal muscle degeneration was depicted as high signal intensity area reflecting its high fat contents. These high signal intensity areas had a longitudinally streaky appearance in parallel direction with myofibers. These findings were more prominent toward myotendon junction than muscle bellies. Skeletal muscle degeneration progressed rapidly between 7 to 10 years of age, and reached a plateau after that. (author)

  1. Motor axon excitability during Wallerian degeneration

    DEFF Research Database (Denmark)

    Moldovan, Mihai; Alvarez, Susana; Krarup, Christian

    2008-01-01

    Axonal loss and degeneration are major factors in determining long-term outcome in patients with peripheral nerve disorders or injury. Following loss of axonal continuity, the isolated nerve stump distal to the lesion undergoes Wallerian degeneration in several phases. In the initial 'latent' phase...... at ankle distal to axotomy were monitored by 'threshold-tracking'. The plantar compound muscle action potentials (CMAPs) were recorded under anesthesia in three animal models: 8-week-old wild-type mice, 8-week-old slow Wallerian degeneration mutant mice and 3-year-old cats. We found that the progressive...... decrease in CMAP following crush injury was associated with slowing of conduction and marked abnormalities in excitability: increased peak threshold deviations during both depolarizing and hyperpolarizing threshold electrotonus, enhanced superexcitability during the recovery cycle and increased rheobase...

  2. Phase space methods for degenerate quantum gases

    CERN Document Server

    Dalton, Bryan J; Barnett, Stephen M

    2015-01-01

    Recent experimental progress has enabled cold atomic gases to be studied at nano-kelvin temperatures, creating new states of matter where quantum degeneracy occurs - Bose-Einstein condensates and degenerate Fermi gases. Such quantum states are of macroscopic dimensions. This book presents the phase space theory approach for treating the physics of degenerate quantum gases, an approach already widely used in quantum optics. However, degenerate quantum gases involve massive bosonic and fermionic atoms, not massless photons. The book begins with a review of Fock states for systems of identical atoms, where large numbers of atoms occupy the various single particle states or modes. First, separate modes are considered, and here the quantum density operator is represented by a phase space distribution function of phase space variables which replace mode annihilation, creation operators, the dynamical equation for the density operator determines a Fokker-Planck equation for the distribution function, and measurable...

  3. Bilateral sphenopalatine ganglion blockade improves postoperative analgesia after endoscopic sinus surgery.

    Science.gov (United States)

    DeMaria, Samuel; Govindaraj, Satish; Chinosorvatana, Nina; Kang, Stanley; Levine, Adam I

    2012-01-01

    Endoscopic sinus surgery (ESS) is a common procedure preferably done with an anesthetic technique ensuring effective postoperative analgesia while speeding discharge home. Although anesthesia administered locally in conjunction with vasoconstricting agents is known to minimize intraoperative bleeding, its usefulness in providing postoperative analgesia has not been well characterized. The results supporting the use of regional anesthesia for sinus surgery have also been limited. Using a randomized, double-blinded and placebo-controlled design, we evaluated recovery times, opioid consumption, and nausea and vomiting after ESS when patients were randomized to either general anesthesia (GA) alone or with regional blockade. Subjects were 70 adults scheduled for sinus surgery. All participants underwent propofol/remifentanil/nitrous oxide anesthesia and similar intraoperative care. Patients received either GA alone or with sphenopalatine ganglion (SPG) blocks in a double-masked study design. Independent observers recorded readiness for discharge, incidence of nausea/vomiting, and pain scores every 15 minutes until discharge. Overall opioid use in the recovery area was also a secondary end point. Twenty-four hours later, patients were called and asked to rate their pain and overall satisfaction with their pain control. Block group participants were considered ready for discharge after 45 minutes and discharged from the hospital ∼40 minutes sooner than GA group participants. The block group required less total fentanyl in the recovery room than did the GA group. The incidences of nausea and vomiting did not differ significantly. Data at 24 hours postoperatively did not differ significantly between groups but trended toward increased satisfaction in the block group. No lasting adverse events were observed. Regional anesthesia using targeted nerve blocks is effective in ESS. The combination of GA and SPG blockade appears to shorten hospital stay and reduce narcotic

  4. [New aspects in age related macular degeneration].

    Science.gov (United States)

    Turlea, C

    2012-01-01

    Being the leading cause of blindness in modern world Age Related Macular Degeneration has beneficiated in the last decade of important progress in diagnosis, classification and the discovery of diverse factors who contribute to the etiology of this disease. Treatments have arised who can postpone the irreversible evolution of the disease and thus preserve vision. Recent findings have identified predisposing genetic factors and also inflamatory and imunological parameters that can be modified trough a good and adequate prevention and therapy This articole reviews new aspects of patology of Age Related Macular Degeneration like the role of complement in maintaining inflamation and the role of oxidative stress on different structures of the retina.

  5. Late complications following cryotherapy of lattice degeneration.

    Science.gov (United States)

    Benson, W E; Morse, P H; Nantawan, P

    1977-10-01

    We observed 341 patients who had received cryotherapy for lattice degeneration in order to identify possible late complications. Sequelae such as retinal tears posterior to an operculum or flap tears within treated areas showed that treatment did not necessarily prevent subsequent vitreous traction. Moreover, the newly created flap tears may extend beyond the treated area and can cause retinal detachment. Even scleral buckling did not necesserily prevent further traction. Therefore, we concluded that when cryotherapy is used to treat lattice degeneration, an adequate margin of surrounding retina should be treated and the treatment should extend to the ora serrata.

  6. Genetics of lattice degeneration of the retina.

    Science.gov (United States)

    Murakami, F; Ohba, N

    1982-01-01

    First-degree relatives of proband patients with lattice degeneration of the retina revealed a significantly higher prevalence of the disease than the prevalence in the general population: the former had the disease about three times as frequently as the latter. The observed data were analyzed in terms of their accordance with recognized genetic models. The inheritance pattern did not fit well to a monogenic mode of inheritance, and it was hypothesized that a polygenic or multifactorial mode of inheritance is the most likely for lattice degeneration of the retina.

  7. CT of sarcomatous degeneration in neurofibromatosis

    International Nuclear Information System (INIS)

    Coleman, B.G.; Arger, P.H.; Dalinka, M.K.; Obringer, A.C.; Raney, B.R.; Meadows, A.T.

    1983-01-01

    Neurofibromatosis is a relatively common disorder that often involves many organ systems. One of the least understood aspects of this malady is a well documented potential for sarcomatous degeneration of neurofibromas. The inability to identify patients at risk and the lack of noninvasive screening methods for symptomatic patients often leads to late diagnosis. In six of seven subsequently proven neurofibrosarcomas, CT demonstrated low-density areas that histopathologically appeared to be due to necrosis, hemorrhage, and/or cystic degeneration. The density differences within these sarcomas were enhanced by the intravenous adminstration of iodinated contrast agents

  8. Magnetic resonance imaging of corticobasal degeneration

    International Nuclear Information System (INIS)

    Ozaki, Yutaka; Maehara, Tadayuki; Izawa, Nana; Suzuki, Michimasa; Komura, Shinji; Nakanishi, Atsushi

    2005-01-01

    The purpose of this paper is to clarify the frequency of each magnetic resonance (MR) finding in corticobasal degeneration (CBD) patients, and to evaluate correlations between the predominant side of MR findings and the most affected side of cortical dysfunction and extrapyramidal symptoms. In 30 patients with clinically diagnosed CBD, MR images were reviewed retrospectively. Two experienced neuroradiologists evaluated previously reported MR findings of CBD (cortical atrophy, subcortical high intensity on T2WI, ventricular dilatation, atrophy of basal ganglia, high or low intensity of basal ganglia on T2WI, and atrophy of corpus callosum) using a 4 step-scale (absent, mild, moderate, and severe). Asymmetrical changes in the cortex and basal ganglia were also evaluated. A neurologist reviewed clinical records of all 30 patients and determined the most affected side of cortical dysfunction and extrapyramidal symptoms. Cortical atrophy was observed in all 30 CBD patients (mild=10, moderate=14, severe=6), particularly at paracentral region (17/30), frontotemporal lobe (6/30), and whole cerebrum (7/30). Other findings such as subcortical high intensity on T2WI (n=11), ventricular dilatation (n=26), atrophy of basal ganglia (n=16), high or low intensity of putamen on T2WI (n=15) were also observed. Asymmetrical atrophic and/or intensity changes were seen in cortex (n=26) and basal ganglia (n=13). Atrophy of corpus callosum was observed in 10 out of the 19 patients who underwent sagittal imaging, and was limited to the middle of corpus callosum. In 16 patients with predominantly left-sided body symptoms due to cortical dysfunction, MR images showed right dominant (n=12) or symmetrical (n=4) cortical atrophy. All 13 patients with predominantly right body symptoms due to cortical dysfunction showed left dominant cortical atrophy on MR images. In 13 patients with predominantly left body extrapyramidal symptoms, MR images showed right dominant (n=3), symmetrical (n=4), or no

  9. MR-guided perineural injection of the ganglion impar: technical considerations and feasibility

    International Nuclear Information System (INIS)

    Marker, David R.; Carrino, John A.; Fritz, Jan; U-Thainual, Paweena; Ungi, Tamas; Fichtinger, Gabor; Flammang, Aaron J.; Iordachita, Iulian I.

    2016-01-01

    Perineural ganglion impar injections are used in the management of pelvic pain syndromes; however, there is no consensus regarding the optimal image guidance. Magnetic resonance imaging (MRI) provides high soft tissue contrast and the potential to directly visualize and target the ganglion. The purpose of this study was to assess the feasibility of MR-guided percutaneous perineural ganglion impar injections. Six MR-guided ganglion impar injections were performed in six human cadavers. Procedures were performed with a clinical 1.5-Tesla MRI system through a far lateral transgluteus approach. Ganglion impar visibility, distance from the sacrococcygeal joint, number of intermittent MRI control steps required to place the needle, target error between the intended and final needle tip location, inadvertent punctures of non-targeted vulnerable structures, injectant distribution, and procedure time were determined. The ganglion impar was seen on MRI in 4/6 (66 %) of cases and located 0.8 mm cephalad to 16.3 mm caudad (average 1.2 mm caudad) to the midpoint of the sacrococcygeal joint. Needle placement required an average of three MRI control steps (range, 2-6). The average target error was 2.2 ± 2.1 mm. In 6/6 cases (100 %), there was appropriate periganglionic distribution and filling of the presacrococcygeal space. No punctures of non-targeted structures occurred. The median procedure time was 20 min (range, 12-29 min). Interventional MRI can visualize and directly target the ganglion impar for accurate needle placement and successful periganglionic injection with the additional benefit of no ionizing radiation exposure to patient and staff. Our results support clinical evaluation. (orig.)

  10. Melanopsin ganglion cells extend dendrites into the outer retina during early postnatal development.

    Science.gov (United States)

    Renna, Jordan M; Chellappa, Deepa K; Ross, Christopher L; Stabio, Maureen E; Berson, David M

    2015-09-01

    Melanopsin ganglion cells express the photopigment melanopsin and are the first functional photoreceptors to develop in the mammalian retina. They have been shown to play a variety of important roles in visual development and behavior in the early postnatal period (Johnson et al., 2010; Kirkby and Feller, 2013; Rao et al., 2013; Renna et al., 2011). Here, we probed the maturation of the dendritic arbors of melanopsin ganglion cells during this developmental period in mice. We found that some melanopsin ganglion cells (mainly the M1-subtype) transiently extend their dendrites not only into the inner plexiform layer (where they receive synaptic inputs from bipolar and amacrine cells) but also into the outer plexiform layer, where in mature retina, rod and cone photoreceptors are thought to contact only bipolar and horizontal cells. Thus, some immature melanopsin ganglion cells are biplexiform. This feature is much less common although still present in the mature retina. It reaches peak incidence 8-12 days after birth, before the eyes open and bipolar cells are sufficiently mature to link rods and cones to ganglion cells. At this age, some outer dendrites of melanopsin ganglion cells lie in close apposition to the axon terminals of cone photoreceptors and express a postsynaptic marker of glutamatergic transmission, postsynaptic density-95 protein (PSD-95). These findings raise the possibility of direct, monosynaptic connections between cones and melanopsin ganglion cells in the early postnatal retina. We provide a detailed description of the developmental profile of these processes and consider their possible functional and evolutionary significance. © 2015 Wiley Periodicals, Inc.

  11. Spatial distribution of excitatory synapses on the dendrites of ganglion cells in the mouse retina.

    Directory of Open Access Journals (Sweden)

    Yin-Peng Chen

    Full Text Available Excitatory glutamatergic inputs from bipolar cells affect the physiological properties of ganglion cells in the mammalian retina. The spatial distribution of these excitatory synapses on the dendrites of retinal ganglion cells thus may shape their distinct functions. To visualize the spatial pattern of excitatory glutamatergic input into the ganglion cells in the mouse retina, particle-mediated gene transfer of plasmids expressing postsynaptic density 95-green fluorescent fusion protein (PSD95-GFP was used to label the excitatory synapses. Despite wide variation in the size and morphology of the retinal ganglion cells, the expression of PSD95 puncta was found to follow two general rules. Firstly, the PSD95 puncta are regularly spaced, at 1-2 µm intervals, along the dendrites, whereby the presence of an excitatory synapse creates an exclusion zone that rules out the presence of other glutamatergic synaptic inputs. Secondly, the spatial distribution of PSD95 puncta on the dendrites of diverse retinal ganglion cells are similar in that the number of excitatory synapses appears to be less on primary dendrites and to increase to a plateau on higher branch order dendrites. These observations suggest that synaptogenesis is spatially regulated along the dendritic segments and that the number of synaptic contacts is relatively constant beyond the primary dendrites. Interestingly, we also found that the linear puncta density is slightly higher in large cells than in small cells. This may suggest that retinal ganglion cells with a large dendritic field tend to show an increased connectivity of excitatory synapses that makes up for their reduced dendrite density. Mapping the spatial distribution pattern of the excitatory synapses on retinal ganglion cells thus provides explicit structural information that is essential for our understanding of how excitatory glutamatergic inputs shape neuronal responses.

  12. Retinal ganglion cell projections to the hamster suprachiasmatic nucleus, intergeniculate leaflet, and visual midbrain: bifurcation and melanopsin immunoreactivity

    Science.gov (United States)

    Morin, Lawrence P.; Blanchard, Jane H.; Provencio, Ignacio

    2003-01-01

    The circadian clock in the suprachiasmatic nucleus (SCN) receives direct retinal input via the retinohypothalamic tract (RHT), and the retinal ganglion cells contributing to this projection may be specialized with respect to direct regulation of the circadian clock. However, some ganglion cells forming the RHT bifurcate, sending axon collaterals to the intergeniculate leaflet (IGL) through which light has secondary access to the circadian clock. The present studies provide a more extensive examination of ganglion cell bifurcation and evaluate whether ganglion cells projecting to several subcortical visual nuclei contain melanopsin, a putative ganglion cell photopigment. The results showed that retinal ganglion cells projecting to the SCN send collaterals to the IGL, olivary pretectal nucleus, and superior colliculus, among other places. Melanopsin-immunoreactive (IR) ganglion cells are present in the hamster retina, and some of these cells project to the SCN, IGL, olivary pretectal nucleus, or superior colliculus. Triple-label analysis showed that melanopsin-IR cells bifurcate and project bilaterally to each SCN, but not to the other visual nuclei evaluated. The melanopsin-IR cells have photoreceptive characteristics optimal for circadian rhythm regulation. However, the presence of moderately widespread bifurcation among ganglion cells projecting to the SCN, and projection by melanopsin-IR cells to locations distinct from the SCN and without known rhythm function, suggest that this ganglion cell type is generalized, rather than specialized, with respect to the conveyance of photic information to the brain. Copyright 2003 Wiley-Liss, Inc.

  13. Establishment of a long-term spiral ganglion neuron culture with reduced glial cell number: Effects of AraC on cell composition and neurons.

    Science.gov (United States)

    Schwieger, Jana; Esser, Karl-Heinz; Lenarz, Thomas; Scheper, Verena

    2016-08-01

    Sensorineural deafness is mainly caused by damage to hair cells and degeneration of the spiral ganglion neurons (SGN). Cochlear implants can functionally replace lost hair cells and stimulate the SGN electrically. The benefit from cochlear implantation depends on the number and excitability of these neurons. To identify potential therapies for SGN protection, in vitro tests are carried out on spiral ganglion cells (SGC). A glial cell-reduced and neuron-enhanced culture of neonatal rat SGC under mitotic inhibition (cytarabine (AraC)) for up to seven days is presented. Serum containing and neurotrophin-enriched cultures with and without AraC-addition were analyzed after 4 and 7 days. The total number of cells was significantly reduced, while the proportion of neurons was greatly increased by AraC-treatment. Cell type-specific labeling demonstrated that nearly all fibroblasts and most of the glial cells were removed. Neither the neuronal survival, nor the neurite outgrowth or soma diameter were negatively affected. Additionally neurites remain partly free of surrounding non-neuronal cells. Recent culture conditions allow only for short-term cultivation of neonatal SGC and lack information on the influence of non-neuronal cells on SGN and of direct contact of neurites with test-materials. AraC-addition reduces the number of non-neuronal cells and increases the ratio of SGN in culture, without negative impact on neuronal viability. This treatment allows longer-term cultivation of SGC and provides deeper insight into SGN-glial cell interaction and the attachment of neurites on test-material surfaces. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  14. Spatially restricted electrical activation of retinal ganglion cells in the rabbit retina by hexapolar electrode return configuration

    Science.gov (United States)

    Habib, Amgad G.; Cameron, Morven A.; Suaning, Gregg J.; Lovell, Nigel H.; Morley, John W.

    2013-06-01

    Objective. Visual prostheses currently in development aim to restore some form of vision to patients suffering from diseases such as age-related macular degeneration and retinitis pigmentosa. Most rely on electrically stimulating inner retinal cells via electrodes implanted on or near the retina, resulting in percepts of light termed ‘phosphenes’. Activation of spatially distinct populations of cells in the retina is key for pattern vision to be produced. To achieve this, the electrical stimulation must be localized, activating cells only in the direct vicinity of the stimulating electrode(s). With this goal in mind, a hexagonal return (hexapolar) configuration has been proposed as an alternative to the traditional monopolar or bipolar return configurations for electrically stimulating the retina. This study investigated the efficacy of the hexapolar configuration in localizing the activation of retinal ganglion cells (RGCs), compared to a monopolar configuration. Approach. Patch-clamp electrophysiology was used to measure the activation thresholds of RGCs in whole-mount rabbit retina to monopolar and hexapolar electrical stimulation, applied subretinally. Main results. Hexapolar activation thresholds for RGCs located outside the hex guard were found to be significantly (>2 fold) higher than those located inside the area of tissue bounded by the hex guard. The hexapolar configuration localized the activation of RGCs more effectively than its monopolar counterpart. Furthermore, no difference in hexapolar thresholds or localization was observed when using cathodic-first versus anodic-first stimulation. Significance. The hexapolar configuration may provide an improved method for electrically stimulating spatially distinct populations of cells in retinal tissue.

  15. Development of a cell-based treatment for long-term neurotrophin expression and spiral ganglion neuron survival.

    Science.gov (United States)

    Zanin, M P; Hellström, M; Shepherd, R K; Harvey, A R; Gillespie, L N

    2014-09-26

    Spiral ganglion neurons (SGNs), the target cells of the cochlear implant, undergo gradual degeneration following loss of the sensory epithelium in deafness. The preservation of a viable population of SGNs in deafness can be achieved in animal models with exogenous application of neurotrophins such as brain-derived neurotrophic factor (BDNF) and neurotrophin-3. For translation into clinical application, a suitable delivery strategy that provides ongoing neurotrophic support and promotes long-term SGN survival is required. Cell-based neurotrophin treatment has the potential to meet the specific requirements for clinical application, and we have previously reported that Schwann cells genetically modified to express BDNF can support SGN survival in deafness for 4 weeks. This study aimed to investigate various parameters important for the development of a long-term cell-based neurotrophin treatment to support SGN survival. Specifically, we investigated different (i) cell types, (ii) gene transfer methods and (iii) neurotrophins, in order to determine which variables may provide long-term neurotrophin expression and which, therefore, may be the most effective for supporting long-term SGN survival in vivo. We found that fibroblasts that were nucleofected to express BDNF provided the most sustained neurotrophin expression, with ongoing BDNF expression for at least 30 weeks. In addition, the secreted neurotrophin was biologically active and elicited survival effects on SGNs in vitro. Nucleofected fibroblasts may therefore represent a method for safe, long-term delivery of neurotrophins to the deafened cochlea to support SGN survival in deafness. Copyright © 2014 IBRO. Published by Elsevier Ltd. All rights reserved.

  16. Neuroprotective effects of tempol acyl esters against retinal ganglion cell death in a rat partial optic nerve crush model.

    Science.gov (United States)

    Thaler, Sebastian; Fiedorowicz, Michal; Grieb, Pawel; Wypych, Zbigniew; Knap, Narcyz; Borowik, Tomasz; Zawada, Katarzyna; Kaminski, Jaroslaw; Wozniak, Michal; Rejdak, Robert; Zrenner, Eberhart; Schuettauf, Frank

    2011-11-01

    The aim of this study is to search for more effective derivatives of the superoxide dismutase mimetic tempol (4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl). Although tempol is neuroprotective in a rat partial optic nerve crush (PONC) model, relatively high doses are required to exert this effect. Tempol acyl esters with different-length fatty acids (tempol-C4, tempol-C8, tempol-C12 and tempol-C16) were synthesized and the following properties were evaluated: water-octanol partition coefficient, liposome-liposome energy transfer, and electron paramagnetic resonance (EPR). Brown Norway rats underwent PONC and received tempol or acyl esters intraperitoneally once daily for 7 consecutive days. We then compared the effects of tempol and its four esters on retinal ganglion cell (RGC) damage using a retrograde labelling method. The water-octanol partition coefficient increased with increasing length of attached acyl chain. However, the energy of the liposome-liposome transfer seemed to be optimal for tempol-C8 and tempol-C12. The EPR signal was very similar for all tested compounds, suggesting similar efficiency of superoxide scavenging. Partial optic nerve crush in vehicle-treated animals reduced RGC numbers by approx. 59% when compared with sham-operated eyes. Tempol did not affect RGC loss at a dose of 1 mg/kg. In contrast, at molar doses equivalent to 1 mg/kg of tempol, tempol-C8 showed a significant neuroprotective effect, whereas tempol-C4, tempol-C12 and tempol-C16 did not act neuroprotectively. Manipulating the hydrophobicity of tempol seems to be a promising tool for developing more potent neuroprotectants in the PONC degeneration model. However, the resulting compounds need further pharmacological evaluation. © 2011 The Authors. Acta Ophthalmologica © 2011 Acta Ophthalmologica Scandinavica Foundation.

  17. Nonthermal leptogenesis with almost degenerate superheavy neutrinos

    NARCIS (Netherlands)

    Allahverdi, Rouzbeh; Mazumdar, Anupam

    We present a model with minimal assumptions for nonthermal leptogenesis with almost degenerate superheavy right-handed neutrinos in a supersymmetric setup. In this scenario the gauge singlet inflaton is directly coupled to the right-handed (s)neutrinos with a mass heavier than the inflaton mass.

  18. Degenerate parabolic stochastic partial differential equations

    Czech Academy of Sciences Publication Activity Database

    Hofmanová, Martina

    2013-01-01

    Roč. 123, č. 12 (2013), s. 4294-4336 ISSN 0304-4149 R&D Projects: GA ČR GAP201/10/0752 Institutional support: RVO:67985556 Keywords : kinetic solutions * degenerate stochastic parabolic equations Subject RIV: BA - General Mathematics Impact factor: 1.046, year: 2013 http://library.utia.cas.cz/separaty/2013/SI/hofmanova-0397241.pdf

  19. MR findings of degenerating parenchymal neurocysticercosis

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Yul; Chung, Eun A; Yang, Ik; Park, Hae Jung; Chung, Soo Young [Hallym Univ. Kangnam Sungshim Hospital, Seoul (Korea, Republic of)

    1996-06-01

    To evaluate MR imaging findings of degenerating parenchymal neurocysticercosis and to determine the characteristics which distinguish it from other brain diseases. MR imagings of 19 patients (56 lesions) of degenerating parenchymal neurocysticercosis were retrospectively evaluated, focusing on the size and location of lesions signal intensity patterns of cyst fluid and wall, the extent of the surrounding edema and features of contrast enhancement. Degenerating parenchymal neurocysticercosis was located in gray or subcortical while matter in 89.3% of 56 lesions (50/56) ; most of these (98.2%) were smaller than 2 cm in diameter. Cyst fluid signal was hyperintense relative to CSF on T1 and proton density weighted images (92.9%). A hypointense signal rim of the cyst wall was noted in the lesions on proton density (92.9%) and T2 weighted (98.2%) images, Surrounding edema was mostly mild. Peripheral rim enhancement was noted in all lesions, and this was frequently irregular and lobulated (67.9%) with a focal defect in the enhancing rim(41.1%). Findings which could be helpful in distinguishing degenerating parencymal neurocysticercosis from other brain diseases are as follows : small, superficial lesions ; hyperintense signal of the cyst fluid on T1 and proton density weighted images ; hypointense signal of the cyst wall on proton density and T2 weighted images ; relatively mild extent of surrounding edema, and peripheral rim enhancement which is frequently irregular and lobulated with a focal defect in the enhancing rim.

  20. Geometry of non-degenerate Susskind fermions

    International Nuclear Information System (INIS)

    Mitra, P.

    1983-01-01

    The Dirac-Kaehler equation on the lattice is known to describe the degenerate ''flavours'' appering in Susskind's approach to lattice fermions. We study the modification that has to be made in this equation in order to lift the degeneracy and give the flavours arbitrary different masses. (orig.)

  1. MR findings of degenerating parenchymal neurocysticercosis

    International Nuclear Information System (INIS)

    Lee, Yul; Chung, Eun A; Yang, Ik; Park, Hae Jung; Chung, Soo Young

    1996-01-01

    To evaluate MR imaging findings of degenerating parenchymal neurocysticercosis and to determine the characteristics which distinguish it from other brain diseases. MR imagings of 19 patients (56 lesions) of degenerating parenchymal neurocysticercosis were retrospectively evaluated, focusing on the size and location of lesions signal intensity patterns of cyst fluid and wall, the extent of the surrounding edema and features of contrast enhancement. Degenerating parenchymal neurocysticercosis was located in gray or subcortical while matter in 89.3% of 56 lesions (50/56) ; most of these (98.2%) were smaller than 2 cm in diameter. Cyst fluid signal was hyperintense relative to CSF on T1 and proton density weighted images (92.9%). A hypointense signal rim of the cyst wall was noted in the lesions on proton density (92.9%) and T2 weighted (98.2%) images, Surrounding edema was mostly mild. Peripheral rim enhancement was noted in all lesions, and this was frequently irregular and lobulated (67.9%) with a focal defect in the enhancing rim(41.1%). Findings which could be helpful in distinguishing degenerating parencymal neurocysticercosis from other brain diseases are as follows : small, superficial lesions ; hyperintense signal of the cyst fluid on T1 and proton density weighted images ; hypointense signal of the cyst wall on proton density and T2 weighted images ; relatively mild extent of surrounding edema, and peripheral rim enhancement which is frequently irregular and lobulated with a focal defect in the enhancing rim

  2. Pigment epithelium-derived factor protects retinal ganglion cells

    Directory of Open Access Journals (Sweden)

    Fleenor Debra L

    2007-01-01

    Full Text Available Abstract Background Retinal ganglion cells (RGCs are responsible for the transmission of visual signals to the brain. Progressive death of RGCs occurs in glaucoma and several other retinal diseases, which can lead to visual impairment and blindness. Pigment epithelium-derived factor (PEDF is a potent antiangiogenic, neurotrophic and neuroprotective protein that can protect neurons from a variety of pathologic insults. We tested the effects of PEDF on the survival of cultured adult rat RGCs in the presence of glaucoma-like insults, including cytotoxicity induced by glutamate or withdrawal of trophic factors. Results Cultured adult rat RGCs exposed to glutamate for 3 days showed signs of cytotoxicity and death. The toxic effect of glutamate was concentration-dependent (EC50 = 31 μM. In the presence of 100 μM glutamate, RGC number decreased to 55 ± 4% of control (mean ± SEM, n = 76; P 50 values of 13.6 ng/mL (glutamate and 3.4 ng/mL (trophic factor withdrawal, respectively. At 100 ng/mL, PEDF completely protected the cells from both insults. Inhibitors of the nuclear factor κB (NFκB and extracellular signal-regulated kinases 1/2 (ERK1/2 significantly reduced the protective effects of PEDF. Conclusion We demonstrated that PEDF potently and efficaciously protected adult rat RGCs from glutamate- and trophic factor withdrawal-mediated cytotoxicity, via the activation of the NFκB and ERK1/2 pathways. The neuroprotective effect of PEDF represents a novel approach for potential treatment of retinopathies, such as glaucoma.

  3. Stellate ganglion block attenuates chronic stress induced depression in rats.

    Directory of Open Access Journals (Sweden)

    Weiwei Wang

    Full Text Available Stress is a significant factor in the etiology of depression. Stellate ganglion block (SGB has been shown to maintain the stability of the autonomic system and to affect the neuroendocrine system, including the hypothalamic-pituitary-adrenal (HPA axis. The objective of this study was to determine the antidepressant-like effects of SGB on the autonomic system and the HPA axis, apoptosis-related proteins, related spatial learning and memory impairment, and sensorimotor dysfunction.Forty-eight Sprague Dawley rats were assigned to four experimental groups: control + saline (sham group, control + SGB (SGB group, unpredictable chronic mild stress (UCMS + saline (UCMS group, and UCMS + SGB (UCSG group. Stress-induced effects and the function of SGB were assessed using measures of body weight, coat state, sucrose consumption, and behavior in open-field and Y-maze tests. Neuronal damage was assessed histologically using the hematoxylin-eosin (HE staining method, while western blotting was used to investigate changes in the expression of apoptosis-related proteins. Plasma corticotropin-releasing factor (CRF, adrenocorticotropic hormone (ACTH, corticosterone (CORT, noradrenaline and adrenaline were measured to evaluate changes in the autonomic system and HPA axis.SGB treatment significantly improved sensorimotor dysfunction and spatial learning and memory impairment following UCMS. Moreover, UCMS significantly decreased body weight, sucrose preference and anti-apoptotic protein Bcl-2, and increased scores on measures of coat state, adrenal gland weight, levels of CORT, CRF, ACTH, noradrenaline and adrenaline, as well as increased neuronal loss, cell shrinkage, nuclear condensation, and the pro-apoptotic protein Bax. These symptoms were attenuated by treatment with SGB.These findings suggest that SGB can attenuate depression-like behaviors induced by chronic stress. These protective effects appear to be due to an anti-apoptotic mechanism of two stress

  4. The celiac ganglion modulates LH-induced inhibition of androstenedione release in late pregnant rat ovaries

    Directory of Open Access Journals (Sweden)

    Rastrilla Ana M

    2006-12-01

    Full Text Available Abstract Background Although the control of ovarian production of steroid hormones is mainly of endocrine nature, there is increasing evidence that the nervous system also influences ovarian steroidogenic output. The purpose of this work was to study whether the celiac ganglion modulates, via the superior ovarian nerve, the anti-steroidogenic effect of LH in the rat ovary. Using mid- and late-pregnant rats, we set up to study: 1 the influence of the noradrenergic stimulation of the celiac ganglion on the ovarian production of the luteotropic hormone androstenedione; 2 the modulatory effect of noradrenaline at the celiac ganglion on the anti-steroidogenic effect of LH in the ovary; and 3 the involvement of catecholaminergic neurotransmitters released in the ovary upon the combination of noradrenergic stimulation of the celiac ganglion and LH treatment of the ovary. Methods The ex vivo celiac ganglion-superior ovarian nerve-ovary integrated system was used. This model allows studying in vitro how direct neural connections from the celiac ganglion regulate ovarian steroidogenic output. The system was incubated in buffer solution with the ganglion and the ovary located in different compartments and linked by the superior ovarian nerve. Three experiments were designed with the addition of: 1 noradrenaline in the ganglion compartment; 2 LH in the ovarian compartment; and 3 noradrenaline and LH in the ganglion and ovarian compartments, respectively. Rats of 15, 19, 20 and 21 days of pregnancy were used, and, as an end point, the concentration of the luteotropic hormone androstenedione was measured in the ovarian compartment by RIA at various times of incubation. For some of the experimental paradigms the concentration of various catecholamines (dihydroxyphenylalanine, dopamine, noradrenaline and adrenaline was also measured in the ovarian compartment by HPLC. Results The most relevant result concerning the action of noradrenaline in the celiac ganglion

  5. Phakic retinal detachment associated with atrophic hole of lattice degeneration of the retina.

    Science.gov (United States)

    Murakami-Nagasako, F; Ohba, N

    1983-01-01

    Forty patients with phakic nontraumatic retinal detachment caused by atrophic retinal hole of lattice degeneration were reviewed. The condition was characterized by insidious, slowly developing shallow detachment, with frequent formation of demarcation lines. Often, the patients did not recognize their visual problems until the detachment had extended to the macular region. Young patients under 40 years of age were more common than older patients. Myopic refractive errors were frequently associated. The results of surgical repair were favorable. The risk of retinal detachment in lattice degeneration with atrophic holes was estimated to be about 1 in 90 patients, and prophylactic treatment for this common anomaly is not readily recommended.

  6. Sphenopalatine ganglion: block, radiofrequency ablation and neurostimulation - a systematic review.

    Science.gov (United States)

    Ho, Kwo Wei David; Przkora, Rene; Kumar, Sanjeev

    2017-12-28

    Sphenopalatine ganglion is the largest collection of neurons in the calvarium outside of the brain. Over the past century, it has been a target for interventional treatment of head and facial pain due to its ease of access. Block, radiofrequency ablation, and neurostimulation have all been applied to treat a myriad of painful syndromes. Despite the routine use of these interventions, the literature supporting their use has not been systematically summarized. This systematic review aims to collect and summarize the level of evidence supporting the use of sphenopalatine ganglion block, radiofrequency ablation and neurostimulation. Medline, Google Scholar, and the Cochrane Central Register of Controlled Trials (CENTRAL) databases were reviewed for studies on sphenopalatine ganglion block, radiofrequency ablation and neurostimulation. Studies included in this review were compiled and analyzed for their treated medical conditions, study design, outcomes and procedural details. Studies were graded using Oxford Center for Evidence-Based Medicine for level of evidence. Based on the level of evidence, grades of recommendations are provided for each intervention and its associated medical conditions. Eighty-three publications were included in this review, of which 60 were studies on sphenopalatine ganglion block, 15 were on radiofrequency ablation, and 8 were on neurostimulation. Of all the studies, 23 have evidence level above case series. Of the 23 studies, 19 were on sphenopalatine ganglion block, 1 study on radiofrequency ablation, and 3 studies on neurostimulation. The rest of the available literature was case reports and case series. The strongest evidence lies in using sphenopalatine ganglion block, radiofrequency ablation and neurostimulation for cluster headache. Sphenopalatine ganglion block also has evidence in treating trigeminal neuralgia, migraines, reducing the needs of analgesics after endoscopic sinus surgery and reducing pain associated with nasal packing

  7. Cardiovascular Disease and its Association with Histological Changes of the Left stellate Ganglion

    Directory of Open Access Journals (Sweden)

    Adam Wood

    2010-01-01

    Full Text Available Mounting evidence has demonstrated that the autonomic system plays a role in the morbidity and mortality of certain cardiovascular disease states. Ventricular arrhythmias have been associated with the level of sympathetic activation. We attempted to determine if the presence of fibrosis, a marker for previous ischemic events, correlates with an increase in the number of left stellate ganglion nerve cell bodies which is indicative of hypersympathetic stimulation to the myocardial tissue. Left stellate ganglia were removed, sectioned and prepared using hematoxylin and eosin and Masson's trichrome stain. The interventricular septum of the heart corresponding to the stellate ganglion samples were removed, serially sectioned, and stained with hematoxylin and eosin and Masson's trichrome stain. The samples were described using a grading scale to quantify the percentage of fibrosis. Ganglion nerve cell bodies were then individually counted in three separate high-powered fields. A student's T-test was used to statistically evaluate the data. Stellate ganglions were sampled from 32 cadavers. Fibrosis was present within 72% (23/32 of the interventricular septums that were sampled. Nine interventricular septums were found to be free of fibrosis. For those interventricular septums that were positive for the presence of fibrosis, the mean left stellate ganglion nerve cell bodies was 39.8 (Range: 26-51. For those interventricular septums that were negative for the presence of fibrosis, the mean left stellate ganglion nerve cell bodies was 34.3 (Range: 27-46. The difference between the mean nerve cell bodies for interventricular septums with fibrosis and without fibrosis was found to be statistically significant ( P = 0.048. Histological changes in terms of the number of left stellate ganglion nerve cell bodies seem to be dependent upon the presence of fibrosis within the interventricular septum. Considering fibrosis of the interventricular septum is a marker

  8. Ganglion cysts of the cruciate ligaments. MR findings with clinical correlation

    Energy Technology Data Exchange (ETDEWEB)

    Huang, G.S.; Hsueh, C.-J.; Juan, C.J.; Chen, C.Y. [Tri-Service General Hospital and National Defense Medical Center, Taipei (China). Dept. of Radiology; Lee, C.H. [Tri-Service General Hospital and National Defense Medical Center, Taipei (China). Dept. of Orthopedic Surgery; Chan, W.P. [Taipei Medical Univ., Wan Fang Hospital, Taipei (China). Dept. of Radiology; Taylor, J.A.M. [New York Chiropractic College, Seneca Falls, NY (United States). Dept. of Diagnosis; Yu, J.S. [Ohio State Univ. Medical Center, Columbus, OH (United States). Dept. of Radiology

    2002-07-01

    Purpose: To evaluate the MR findings of ganglion cysts of the cruciate ligaments in correlation with clinical findings. Material and Methods:We reviewed 12 patients with ganglion cysts of the cruciate ligaments obtained from a medical record of 4153 consecutive patients referred for knee MR examinations. All patients presented with chronic knee pain and 4 had restriction of knee motion. The MR imaging findings of the cysts were evaluated and correlated with clinical manifestations. Results:Seven ganglion cysts were found in the posterior cruciate ligaments and 5 in the anterior cruciate ligaments. All cysts were lobulated (n=7) or fusiform (n=5) in shape, 1.8-4.5 cm in size, along the posterior surface in the proximal or distal end of the ligaments. Ten patients had arthroscopic resection or aspiration of their cysts, became symptom free and had no recurrence on follow-up MR examinations. Two cysts reduced in size spontaneously by conservative treatment. Conclusion:MR imaging can offer useful information in detection and diagnosis of patients with chronic knee pain due to ganglion cysts of the cruciate ligaments. The size and location of the ganglion cysts can attribute to the clinical manifestations.

  9. Hypothermia Protects and Prolongs the Tolerance Time of Retinal Ganglion Cells against Ischemia.

    Directory of Open Access Journals (Sweden)

    Maximilian Schultheiss

    Full Text Available Hypothermia has been shown to be neuroprotective in the therapy of ischemic stroke in the brain. To date no studies exist on the level of the inner retina and it is unclear if hypothermia would prolong the ischemic tolerance time of retinal ganglion cells, which are decisive in many ischemic retinopathies.Bovine eyes were enucleated and stored either at 21°C or 37°C for 100 or 340 minutes, respectively. Afterwards the globes were dissected, the retina was prepared and either the spontaneous ganglion cell responses were measured or the retina was incubated as an organotypic culture for additional 24 hours. After incubation the retina was either processed for histology (H&E and DAPI staining or real-time PCR (Thy-1 expression was performed.Hypothermia prolonged ganglion cell survival up to 340 minutes under ischemic conditions. In contrast to eyes kept at 37°C the eyes stored at 21°C still showed spontaneous ganglion cell spiking (56.8% versus 0%, a 5.8 fold higher Thy-1 mRNA expression (not significant, but a trend and a preserved retinal structure after 340 minutes of ischemia.Hypothermia protects retinal ganglion cells against ischemia and prolongs their ischemic tolerance time.

  10. TRPC1 is required for survival and proliferation of cochlear spiral ganglion stem/progenitor cells.

    Science.gov (United States)

    Chen, Hsin-Chien; Wang, Chih-Hung; Shih, Cheng-Ping; Chueh, Sheau-Huei; Liu, Shu-Fan; Chen, Hang-Kang; Lin, Yi-Chun

    2015-12-01

    The present studies were designed to test the hypothesis that canonical transient receptor potential channel 1 (TRPC1) is required for the proliferation of cochlear spiral ganglion stem/progenitor cells (SPCs). TRPC1 were detected and evaluated in postnatal day 1 CBA/CaJ mice pups derived-cochlear spiral ganglion SPCs by reverse transcription-polymerase chain reaction, Western blot, immunocytochemistry, and calcium imaging. The cell viability and proliferation of the spiral ganglion SPCs following si-RNA mediated knockdown of TRPC1 or addition of TRPC channel blocker SKF9635 were compared to controls. In spiral ganglion SPCs, TRPC1 was found to be the most abundantly expressed TRPC subunit and shown to contribute to store-operated calcium entry. Silencing of TRPC1 or addition of TRPC channel blockers significantly decreased the rate of cell proliferation. The results suggest that TRPC1 might serve as an essential molecule in regulating the proliferation of spiral ganglion SPCs. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  11. Ganglion cysts of the cruciate ligaments. MR findings with clinical correlation

    International Nuclear Information System (INIS)

    Huang, G.S.; Hsueh, C.-J.; Juan, C.J.; Chen, C.Y.; Lee, C.H.; Chan, W.P.; Taylor, J.A.M.; Yu, J.S.

    2002-01-01

    Purpose: To evaluate the MR findings of ganglion cysts of the cruciate ligaments in correlation with clinical findings. Material and Methods:We reviewed 12 patients with ganglion cysts of the cruciate ligaments obtained from a medical record of 4153 consecutive patients referred for knee MR examinations. All patients presented with chronic knee pain and 4 had restriction of knee motion. The MR imaging findings of the cysts were evaluated and correlated with clinical manifestations. Results:Seven ganglion cysts were found in the posterior cruciate ligaments and 5 in the anterior cruciate ligaments. All cysts were lobulated (n=7) or fusiform (n=5) in shape, 1.8-4.5 cm in size, along the posterior surface in the proximal or distal end of the ligaments. Ten patients had arthroscopic resection or aspiration of their cysts, became symptom free and had no recurrence on follow-up MR examinations. Two cysts reduced in size spontaneously by conservative treatment. Conclusion:MR imaging can offer useful information in detection and diagnosis of patients with chronic knee pain due to ganglion cysts of the cruciate ligaments. The size and location of the ganglion cysts can attribute to the clinical manifestations

  12. Electrical receptive fields of retinal ganglion cells: Influence of presynaptic neurons.

    Science.gov (United States)

    Maturana, Matias I; Apollo, Nicholas V; Garrett, David J; Kameneva, Tatiana; Cloherty, Shaun L; Grayden, David B; Burkitt, Anthony N; Ibbotson, Michael R; Meffin, Hamish

    2018-02-01

    Implantable retinal stimulators activate surviving neurons to restore a sense of vision in people who have lost their photoreceptors through degenerative diseases. Complex spatial and temporal interactions occur in the retina during multi-electrode stimulation. Due to these complexities, most existing implants activate only a few electrodes at a time, limiting the repertoire of available stimulation patterns. Measuring the spatiotemporal interactions between electrodes and retinal cells, and incorporating them into a model may lead to improved stimulation algorithms that exploit the interactions. Here, we present a computational model that accurately predicts both the spatial and temporal nonlinear interactions of multi-electrode stimulation of rat retinal ganglion cells (RGCs). The model was verified using in vitro recordings of ON, OFF, and ON-OFF RGCs in response to subretinal multi-electrode stimulation with biphasic pulses at three stimulation frequencies (10, 20, 30 Hz). The model gives an estimate of each cell's spatiotemporal electrical receptive fields (ERFs); i.e., the pattern of stimulation leading to excitation or suppression in the neuron. All cells had excitatory ERFs and many also had suppressive sub-regions of their ERFs. We show that the nonlinearities in observed responses arise largely from activation of presynaptic interneurons. When synaptic transmission was blocked, the number of sub-regions of the ERF was reduced, usually to a single excitatory ERF. This suggests that direct cell activation can be modeled accurately by a one-dimensional model with linear interactions between electrodes, whereas indirect stimulation due to summated presynaptic responses is nonlinear.

  13. Distribution of 5-HT1FReceptors in Monkey Vestibular and Trigeminal Ganglion Cells.

    Science.gov (United States)

    Usman, Habiba O; Balaban, Carey D

    2016-01-01

    Evidence of serotonergic involvement in vestibular pathway contributions to migraine and balance disorders is compelling. Serotonergic 5-HT 1B and 5-HT 1D receptors are expressed extensively in inner ear ganglia of monkeys and rats. The serotonergic 5-HT 1F receptor is also a target of triptans. This study describes its distribution in vestibular and trigeminal ganglia of monkeys. Using primary polyclonal antibodies raised against oligopeptides specific for the human 5-HT 1F receptor, neuronal somatic area and intensity of immunoreactive vestibular and trigeminal ganglia were quantified. Virtually all vestibular and considerable trigeminal ganglia showed positive 5-HT 1F receptor immunoreactivity. Inferior and superior vestibular ganglia staining appeared confined to distinct cell regions, varying considerably among cells of different sizes: more intense in small, punctate in some medium and regionally polarized in some large cells. Analyses of average somatic vestibular neuronal immunoreactive intensity identified mainly medium sized cells with high standard deviation of intensity corresponding to punctately stained cells. Less variability occurred in somatic intensity staining and cellular distribution among 5-HT 1F receptor immunopositive trigeminal ganglia. Most exhibited similar punctate staining patterns, higher mean somatic immunoreactive intensity and larger neuronal somatic size proportions per size distribution subpopulation compared to vestibular ganglia size distribution populations. Centrally directed vestibular ganglion neuronal processes, cochlear inner hair cells, vestibular hair cells and blood vessels in vestibular maculae and cristae were immunoreactive. The 5-HT 1F receptor expression in vestibular ganglia shows complex variable staining intensity patterns associated with cell size of immunopositive neurons, not seen in immunopositive trigeminal ganglia and not previously evident with 5-HT 1B and 5-HT 1D receptor subtype immunoreactivity in

  14. MR imaging of central nervous system white matter tract degeneration (Wallerian degeneration)

    International Nuclear Information System (INIS)

    Kuhn, M.J.; Johnson, K.A.; Davis, K.R.

    1987-01-01

    Wallerian degeneration is readily demonstrated by MR imaging. Twenty-one patients with MR signal abnormalities in various central nervous system (CNS) white matter tracts were evaluated with regard to (1) nature of signal abnormality, (2) MR anatomy of the involved tract, and (3) primary pathology (e.g., infarct, tumor, hemorrhage). Most examples of wallerian degeneration result in a thin, continuous band of long T1, long T2 signal abnormality conforming to the known anatomic pathway of a CNS axonal tract. Old, large cortical infarcts have the greatest propensity to show subsequent white-matter tract degeneration. Corticospinal tract degeneration is the type most readily visualized, often seen extending completely from the cerebral cortex through the medulla

  15. Ethanol Exposure Causes Muscle Degeneration in Zebrafish

    Directory of Open Access Journals (Sweden)

    Elizabeth C. Coffey

    2018-03-01

    Full Text Available Alcoholic myopathies are characterized by neuromusculoskeletal symptoms such as compromised movement and weakness. Although these symptoms have been attributed to neurological damage, EtOH may also target skeletal muscle. EtOH exposure during zebrafish primary muscle development or adulthood results in smaller muscle fibers. However, the effects of EtOH exposure on skeletal muscle during the growth period that follows primary muscle development are not well understood. We determined the effects of EtOH exposure on muscle during this phase of development. Strikingly, muscle fibers at this stage are acutely sensitive to EtOH treatment: EtOH induces muscle degeneration. The severity of EtOH-induced muscle damage varies but muscle becomes more refractory to EtOH as muscle develops. NF-kB induction in muscle indicates that EtOH triggers a pro-inflammatory response. EtOH-induced muscle damage is p53-independent. Uptake of Evans blue dye shows that EtOH treatment causes sarcolemmal instability before muscle fiber detachment. Dystrophin-null sapje mutant zebrafish also exhibit sarcolemmal instability. We tested whether Trichostatin A (TSA, which reduces muscle degeneration in sapje mutants, would affect EtOH-treated zebrafish. We found that TSA and EtOH are a lethal combination. EtOH does, however, exacerbate muscle degeneration in sapje mutants. EtOH also disrupts adhesion of muscle fibers to their extracellular matrix at the myotendinous junction: some detached muscle fibers retain beta-Dystroglycan indicating failure of muscle end attachments. Overexpression of Paxillin, which reduces muscle degeneration in zebrafish deficient for beta-Dystroglycan, is not sufficient to rescue degeneration. Taken together, our results suggest that EtOH exposure has pleiotropic deleterious effects on skeletal muscle.

  16. The morphological characterization of orientation-biased displaced large-field ganglion cells in the central part of goldfish retina.

    Science.gov (United States)

    Hoshi, Hideo; Sato, Fumi

    2018-02-01

    The vertebrate retina has about 30 subtypes of ganglion cells. Each ganglion cell receives synaptic inputs from specific types of bipolar and amacrine cells ramifying at the same depth of the inner plexiform layer (IPL), each of which is thought to process a specific aspect of visual information. Here, we identified one type of displaced ganglion cell in the goldfish retina which had a large and elongated dendritic field. As a population, all of these ganglion cells were oriented in the horizontal axis and perpendicular to the dorsal-ventral axis of the goldfish eye in the central part of retina. This ganglion cell has previously been classified as Type 1.2. However, the circuit elements which synapse with this ganglion cell are not yet characterized. We found that this displaced ganglion cell was directly tracer-coupled only with homologous ganglion cells at sites containing Cx35/36 puncta. We further illustrated that the processes of dopaminergic neurons often terminated next to intersections between processes of ganglion cells, close to where dopamine D1 receptors were localized. Finally, we showed that Mb1 ON bipolar cells had ribbon synapses in the axonal processes passing through the IPL and made ectopic synapses with this displaced ganglion cell that stratified into stratum 1 of the IPL. These results suggest that the displaced ganglion cell may synapse with both Mb1 cells using ectopic ribbon synapses and OFF cone bipolar cells with regular ribbon synapses in the IPL to function in both scotopic and photopic light conditions. © 2017 Wiley Periodicals, Inc.

  17. Matrix Remodeling During Intervertebral Disc Growth and Degeneration Detected by Multichromatic FAST Staining

    Science.gov (United States)

    Leung, Victor Y.L.; Chan, Wilson C.W.; Hung, Siu-Chun; Cheung, Kenneth M.C.; Chan, Danny

    2009-01-01

    Various imaging techniques have been used to assess degeneration of the intervertebral disc, including many histological methods, but cartilage-oriented histological stains do not clearly show the comparatively complex structures of the disc. In addition, there is no integrated method to assess efficiently both the compartmental organization and matrix composition in disc samples. In this study, a novel histological method, termed FAST staining, has been developed to investigate disc growth and degeneration by sequential staining with fast green, Alcian blue, Safranin-O, and tartrazine to generate multichromatic histological profiles (FAST profiles). This identifies the major compartments of the vertebra-disc region, including the cartilaginous endplate and multiple zones of the annulus fibrosus, by specific FAST profile patterns. A disc degeneration model in rabbit established using a previously described puncture method showed gradual but profound alteration of the FAST profile during disc degeneration, supporting continual alteration of glycosaminoglycan. Changes of the FAST profile pattern in the nucleus pulposus and annulus fibrosus of the postnatal mouse spine suggested matrix remodeling activity during the growth of intervertebral discs. In summary, we developed an effective staining method capable of defining intervertebral disc compartments in detail and showing matrix remodeling events within the disc. The FAST staining method may be used to develop a histopathological grading system to evaluate disc degeneration or malformation. (J Histochem Cytochem 57:249–256, 2009) PMID:19001641

  18. Valproic acid prevents retinal degeneration in a murine model of normal tension glaucoma.

    Science.gov (United States)

    Kimura, Atsuko; Guo, Xiaoli; Noro, Takahiko; Harada, Chikako; Tanaka, Kohichi; Namekata, Kazuhiko; Harada, Takayuki

    2015-02-19

    Valproic acid (VPA) is widely used for treatment of epilepsy, mood disorders, migraines and neuropathic pain. It exerts its therapeutic benefits through modulation of multiple mechanisms including regulation of gamma-aminobutyric acid and glutamate neurotransmissions, activation of pro-survival protein kinases and inhibition of histone deacetylase. The evidence for neuroprotective properties associated with VPA is emerging. Herein, we investigated the therapeutic potential of VPA in a mouse model of normal tension glaucoma (NTG). Mice with glutamate/aspartate transporter gene deletion (GLAST KO mice) demonstrate progressive retinal ganglion cell (RGC) loss and optic nerve degeneration without elevated intraocular pressure, and exhibit glaucomatous pathology including glutamate neurotoxicity and oxidative stress in the retina. VPA (300mg/kg) or vehicle (PBS) was administered via intraperitoneal injection in GLAST KO mice daily for 2 weeks from the age of 3 weeks, which coincides with the onset of glaucomatous retinal degeneration. Following completion of the treatment period, the vehicle-treated GLAST KO mouse retina showed significant RGC death. Meanwhile, VPA treatment prevented RGC death and thinning of the inner retinal layer in GLAST KO mice. In addition, in vivo electrophysiological analyses demonstrated that visual impairment observed in vehicle-treated GLAST KO mice was ameliorated with VPA treatment, clearly establishing that VPA beneficially affects both histological and functional aspects of the glaucomatous retina. We found that VPA reduces oxidative stress induced in the GLAST KO retina and stimulates the cell survival signalling pathway associated with extracellular-signal-regulated kinases (ERK). This is the first study to report the neuroprotective effects of VPA in an animal model of NTG. Our findings raise intriguing possibilities that the widely prescribed drug VPA may be a novel candidate for treatment of glaucoma. Copyright © 2015 Elsevier

  19. A novel retinal oscillation mechanism in an autosomal dominant photoreceptor degeneration mouse model

    Directory of Open Access Journals (Sweden)

    Hung-Ya eTu

    2016-01-01

    Full Text Available It has been shown in rd1 and rd10 models of photoreceptor degeneration (PD that inner retinal neurons display spontaneous and rhythmic activities. Furthermore, the rhythmic activity has been shown to require the gap junction protein connexin 36, which is likely located in AII amacrine cells (AII-ACs. In the present study, an autosomal dominant PD model called rhoΔCTA, whose rods overexpress a C-terminally truncated mutant rhodopsin and degenerate with a rate similar to that of rd1, was used to investigate the generality and mechanisms of heightened inner retinal activity following PD. To fluorescently identify cholinergic starburst amacrine cells (SACs, the rhoΔCTA mouse was introduced into a combined ChAT-IRES-Cre and Ai9 background. In this mouse, we observed large amplitude excitatory postsynaptic currents (EPSCs oscillations and non-rhythmic inhibitory postsynaptic currents (IPSCs in both ON- and OFF-SACs. The IPSCs were more noticeable in OFF- than in ON-SACs. Similar to reported retinal ganglion cell (RGC oscillation in rd1 mice, EPSC oscillation was synaptically driven by glutamate and sensitive to blockade of NaV channels and gap junctions. These data suggest that akin to rd1 mice, AII-AC is a prominent oscillator in rhoΔCTA mice. Surprisingly, OFF-SAC but not ON-SAC EPSC oscillation could readily be enhanced by GABAergic blockade. More importantly, weakening the AII-AC gap junction network by activating retinal dopamine receptors abolished oscillations in ON-SACs but not in OFF-SACs. Furthermore, the latter persisted in the presence of flupirtine, an M-type potassium channel activator recently reported to dampen intrinsic AII-AC bursting. These data suggest the existence of a novel oscillation mechanism in mice with PD.

  20. Calcium channel blockers inhibit retinal degeneration in the retinal-degeneration-B mutant of Drosophila.

    Science.gov (United States)

    Sahly, I; Bar Nachum, S; Suss-Toby, E; Rom, A; Peretz, A; Kleiman, J; Byk, T; Selinger, Z; Minke, B

    1992-01-01

    Light accelerates degeneration of photoreceptor cells of the retinal degeneration B (rdgB) mutant of Drosophila. During early stages of degeneration, light stimuli evoke spikes from photoreceptors of the mutant fly; no spikes can be recorded from photoreceptors of the wild-type fly. Production of spike potentials from mutant photoreceptors was blocked by diltiazem, verapamil hydrochloride, and cadmium. Little, if any, effect of the (-)-cis isomer or (+)-cis isomer of diltiazem on the light response was seen. Further, the (+)-cis isomer was approximately 50 times more effective than the (-)-cis isomer in blocking the Ca2+ spikes, indicating that diltiazem action on the rdgB eye is mediated by means of blocking voltage-sensitive Ca2+ channels, rather than by blocking the light-sensitive channels. Application of the Ca(2+)-channel blockers (+)-cis-diltiazem and verapamil hydrochloride to the eyes of rdgB flies over a 7-day period largely inhibited light-dependent degeneration of the photoreceptor cells. Pulse labeling with [32P]phosphate showed much greater incorporation into eye proteins of [32P]phosphate in rdgB flies than in wild-type flies. Retarding the light-induced photoreceptor degeneration in the mutant by Ca(2+)-channel blockers, thus, suggests that toxic increase in intracellular Ca2+ by means of voltage-gated Ca2+ channels, possibly secondary to excessive phosphorylation, leads to photoreceptor degeneration in the rdgB mutant. Images PMID:1309615

  1. Mucoid degeneration of the anterior cruciate Ligament: a case report ...

    African Journals Online (AJOL)

    We report a case of mucoid degeneration of the anterior cruciate ligament (ACL). Mucoid degeneration of the ACL is a very rare cause of knee pain. There have been only some reported cases of mucoid degeneration of the ACL in the English literature. We reviewed previous reports and summarized clinical features and ...

  2. Degenerate r-Stirling Numbers and r-Bell Polynomials

    Science.gov (United States)

    Kim, T.; Yao, Y.; Kim, D. S.; Jang, G.-W.

    2018-01-01

    The purpose of this paper is to exploit umbral calculus in order to derive some properties, recurrence relations, and identities related to the degenerate r-Stirling numbers of the second kind and the degenerate r-Bell polynomials. Especially, we will express the degenerate r-Bell polynomials as linear combinations of many well-known families of special polynomials.

  3. Genetics and molecular pathology of Stargardt-like macular degeneration.

    Science.gov (United States)

    Vasireddy, Vidyullatha; Wong, Paul; Ayyagari, Radha

    2010-05-01

    Stargardt-like macular degeneration (STGD3) is an early onset, autosomal dominant macular degeneration. STGD3 is characterized by a progressive pathology, the loss of central vision, atrophy of the retinal pigment epithelium, and accumulation of lipofuscin, clinical features that are also characteristic of age-related macular degeneration. The onset of clinical symptoms in STGD3, however, is typically observed within the second or third decade of life (i.e., starting in the teenage years). The clinical profile at any given age among STGD3 patients can be variable suggesting that, although STGD3 is a single gene defect, other genetic or environmental factors may play a role in moderating the final disease phenotype. Genetic studies localized the STGD3 disease locus to a small region on the short arm of human chromosome 6, and application of a positional candidate gene approach identified protein truncating mutations in the elongation of very long chain fatty acids-4 gene (ELOVL4) in patients with this disease. The ELOVL4 gene encodes a protein homologous to the ELO group of proteins that participate in fatty acid elongation in yeast. Pathogenic mutations found in the ELOVL4 gene result in altered trafficking of the protein and behave with a dominant negative effect. Mice carrying an Elovl4 mutation developed photoreceptor degeneration and depletion of very long chain fatty acids (VLCFA). ELOVL4 protein participates in the synthesis of fatty acids with chain length longer than 26 carbons. Studies on ELOVL4 indicate that VLCFA may be necessary for normal function of the retina, and the defective protein trafficking and/or altered VLCFA elongation underlies the pathology associated with STGD3. Determining the role of VLCFA in the retina and discerning the implications of abnormal trafficking of mutant ELOVL4 and depleted VLCFA content in the pathology of STGD3 will provide valuable insight in understanding the retinal structure, function, and pathology underlying STGD3

  4. Tibial nerve intraneural ganglion cyst in a 10-year-old boy

    Energy Technology Data Exchange (ETDEWEB)

    Squires, Judy H. [University of Cincinnati College of Medicine, Department of Radiology, Cincinnati, OH (United States); Emery, Kathleen H.; Johnson, Neil [Cincinnati Children' s Hospital Medical Center, Division of Radiology, Cincinnati, OH (United States); Sorger, Joel [Cincinnati Children' s Hospital Medical Center, Division of Orthopedics, Cincinnati, OH (United States)

    2014-04-15

    Intraneural ganglion cysts are uncommon cystic lesions of peripheral nerves that are typically encountered in adults. In the lower extremity, the peroneal nerve is most frequently affected with involvement of the tibial nerve much less common. This article describes a tibial intraneural ganglion cyst in a 10-year-old boy. Although extremely rare, intraneural ganglion cysts of the tibial nerve should be considered when a nonenhancing cystic structure with intra-articular extension is identified along the course of the nerve. This report also details the unsuccessful attempt at percutaneous treatment with US-guided cyst aspiration and steroid injection, an option recently reported as a viable alternative to open surgical resection. (orig.)

  5. A rare case of intraneural ganglion cyst involving the tibial nerve.

    Science.gov (United States)

    Patel, Purvak; Schucany, William G

    2012-04-01

    Cystic lesions around the knee are a relatively common occurrence. Several types of cysts have been reported, including synovial, bursal, and ganglion. Ganglion cysts are not lined by synovial cells. Their location is highly variable, with occurrences described in the fat pads near the tibia or femur, muscles, nerves, and arteries. Intraneural ganglia are rare nonneoplastic cysts caused by the accumulation of thick mucinous fluid within the epineurium of peripheral nerves, encased in a dense fibrous capsule. These cysts can cause compression of the adjacent nerve fascicles, resulting in pain, paresthesias, weakness, muscle denervation, and atrophy. They are most commonly manifested by local and radiating pain, but sensory and motor deficits have also been described. Involvement of the tibial nerve is exceptionally rare, with ganglion cyst in a young woman. We also discuss the imaging features, differential considerations, proposed pathogenesis and anatomic origin, and treatment of this rare entity.

  6. Strychnine blocks transient but not sustained inhibition in mudpuppy retinal ganglion cells.

    Science.gov (United States)

    Belgum, J H; Dvorak, D R; McReynolds, J S

    1984-01-01

    Transient and sustained inhibitory synaptic inputs to on-centre, off-centre, and on-off ganglion cells in the mudpuppy retina were studied using intracellular recording in the superfused eye-cup preparation. When chemical transmission was blocked with 4 mM-Co2+, application of either glycine or gamma-aminobutyric acid (GABA) caused a hyperpolarization and conductance increase in all ganglion cells. For both amino acids, the responses were dose dependent in the range 0.05-10 mM, with a half-maximal response at about 0.7 mM. Glycine and GABA sensitivities were very similar in all three types of ganglion cells. The response to applied glycine was selectively antagonized by 10(-5) M-strychnine and the response to applied GABA was selectively antagonized by 10(-5) M-picrotoxin. In all ganglion cells, 10(-5) M-strychnine eliminated the transient inhibitory events which occur at the onset and termination of a light stimulus. The block of transient inhibition was associated with a relative depolarization of membrane potential and decrease in conductance at these times. Strychnine had no effect on membrane potential or conductance in darkness or during sustained inhibitory responses to light. Picrotoxin (10(-5) M) did not block transient inhibitory events in any ganglion cells, but did affect other components of their responses. The results suggest that in all three classes of ganglion cells transient inhibition, but not sustained inhibition, may be mediated by glycine or a closely related substance. PMID:6481635

  7. Dominant inheritance of retinal ganglion cell resistance to optic nerve crush in mice

    Directory of Open Access Journals (Sweden)

    Schlamp Cassandra L

    2007-03-01

    Full Text Available Abstract Background Several neurodegenerative diseases are influenced by complex genetics that affect an individual's susceptibility, disease severity, and rate of progression. One such disease is glaucoma, a chronic neurodegenerative condition of the eye that targets and stimulates apoptosis of CNS neurons called retinal ganglion cells. Since ganglion cell death is intrinsic, it is reasonable that the genes that control this process may contribute to the complex genetics that affect ganglion cell susceptibility to disease. To determine if genetic background influences susceptibility to optic nerve damage, leading to ganglion cell death, we performed optic nerve crush on 15 different inbred lines of mice and measured ganglion cell loss. Resistant and susceptible strains were used in a reciprocal breeding strategy to examine the inheritance pattern of the resistance phenotype. Because earlier studies had implicated Bax as a susceptibility allele for ganglion cell death in the chronic neurodegenerative disease glaucoma, we conducted allelic segregation analysis and mRNA quantification to assess this gene as a candidate for the cell death phenotype. Results Inbred lines showed varying levels of susceptibility to optic nerve crush. DBA/2J mice were most resistant and BALB/cByJ mice were most susceptible. F1 mice from these lines inherited the DBA/2J phenotype, while N2 backcross mice exhibited the BALB/cByJ phenotype. F2 mice exhibited an intermediate phenotype. A Wright Formula calculation suggested as few as 2 dominant loci were linked to the resistance phenotype, which was corroborated by a Punnett Square analysis of the distribution of the mean phenotype in each cross. The levels of latent Bax mRNA were the same in both lines, and Bax alleles did not segregate with phenotype in N2 and F2 mice. Conclusion Inbred mice show different levels of resistance to optic nerve crush. The resistance phenotype is heritable in a dominant fashion involving

  8. Dissection of the sentry ganglion by laparoscopic boarding in patients with cervix uterine cancer clinical stages IA2 at IIB

    International Nuclear Information System (INIS)

    Valdez U, J.J.; Pichardo M, P.A.; Cortes M, G.; Escudero de los Rios, P.

    2005-01-01

    The obtained results in presently study demonstrate that the feasibility of the detection of the sentry ganglion in cervix uterine cancer using a boarding by laparoscopic via, being necessary the use of twice labelled as much with patent blue and radioisotope (colloid of labelled rhenium with 99m Tc, total dose of 3 MCi) to achieve the identification of the ganglion. (Author)

  9. Displaced retinal ganglion cells in albino and pigmented rats

    Directory of Open Access Journals (Sweden)

    Francisco Manuel Nadal-Nicolás

    2014-10-01

    Full Text Available We have studied in parallel the population of displaced retinal ganglion cells (dRGCs and normally placed (orthotopic RGCs, oRGCs in albino and pigmented rats. Using retrograde tracing from the optic nerve, from both superior colliculi (SC or from the ipsilateral SC in conjunction with Brn3 and melanopsin immunodetection, we report for the first time their total number and topography as well as the number and distribution of those dRGCs and oRGCs that project ipsi- or contralaterally and/or that express any of the three Brn3 isoforms or melanopsin. The total number of RGCs (oRGCs+dRGCs is 84,706±1,249 in albino and 90,440±2,236 in pigmented, out of which 2,383 and 2,428 are melanopsin positive (m-RGCs, respectively. Regarding dRGCs: i/ albino rats have a significantly lower number of dRGCs than pigmented animals (0.5% of the total number of RGCs vs. 2.5%, respectively, ii/ dRGCs project massively to the contralateral SC, iii/ the percentage of ipsilaterality is higher for dRGCs than for oRGCs, iv/ a higher proportion of ipsilateral dRGCs is observed in albino than pigmented animals, v/ dRGC topography is very specific, they predominate in the equatorial temporal retina, being densest where the oRGCs are densest, vi/ Brn3a detects all dRGCs except half of the ipsilateral ones and those that express melanopsin, vii/ the proportion of dRGCs that express Brn3b or Brn3c is slightly lower than in the oRGC population, viii/ a higher percentage of dRGCs (13% albino, 9% pigmented than oRGCs (2.6% express melanopsin, ix/ few m-RGCs (displaced and orthotopic project to the ipsilateral SC, x/ the topography of m-dRGCs does not resemble the general distribution of dRGCs, xi/ The soma size in m-oRGCs ranges from 10 to 21 µm and in m-dRGCs from 8 to 15 µm, xii/ oRGCs and dRGCs have the same susceptibility to axonal injury and hypertension. Although the role of mammalian dRGCs remains to be determined, our data suggest that they are not misplaced by an

  10. Retinal ganglion cells: Energetics, compartmentation, axonal transport, cytoskeletons and vulnerability.

    Science.gov (United States)

    Yu, Dao-Yi; Cringle, Stephen J; Balaratnasingam, Chandrakumar; Morgan, William H; Yu, Paula K; Su, Er-Ning

    2013-09-01

    Retinal ganglion cells (RGCs) are specialized projection neurons that relay an immense amount of visual information from the retina to the brain. RGC signal inputs are collected by dendrites and output is distributed from the cell body via very thin (0.5-1 μm) and long (∼50 mm) axons. The RGC cell body is larger than other retinal neurons, but is still only a very small fraction (one ten thousandths) of the length and total surface area of the axon. The total distance traversed by RGCs extends from the retina, starting from synapses with bipolar and amacrine cells, to the brain, to synapses with neurons in the lateral geniculate nucleus. This review will focus on the energy demands of RGCs and the relevant tissues that surround them. RGC survival and function unexceptionally depends upon free energy, predominantly adenosine triphosphate (ATP). RGC energy metabolism is vastly different when compared to that of the photoreceptors. Each subcellular component of the RGC is remarkably different in terms of structure, function and extracellular environment. The energy demands and distribution of each component are also distinct as evidenced by the uneven distribution of mitochondria and ATP within the RGC - signifying the presence of intracellular energy gradients. In this review we will describe RGCs as having four subcellular components, (1) Dendrites, (2) Cell body, (3) Non-myelinated axon, including intraocular and optic nerve head portions, and (4) Myelinated axon, including the intra-orbital and intracranial portions. We will also describe how RGCs integrate information from each subcellular component in order achieve intracellular homeostatic stability as well as respond to perturbations in the extracellular environment. The possible cellular mechanisms such as axonal transport and axonal cytoskeleton proteins that are involved in maintaining RGC energy homeostasis during normal and disease conditions will also be discussed in depth. The emphasis of this

  11. Neuroprotection, Growth Factors and BDNF-TrkB Signalling in Retinal Degeneration

    Directory of Open Access Journals (Sweden)

    Atsuko Kimura

    2016-09-01

    Full Text Available Neurotrophic factors play key roles in the development and survival of neurons. The potent neuroprotective effects of neurotrophic factors, including brain-derived neurotrophic factor (BDNF, ciliary neurotrophic factor (CNTF, glial cell-line derived neurotrophic factor (GDNF and nerve growth factor (NGF, suggest that they are good therapeutic candidates for neurodegenerative diseases. Glaucoma is a neurodegenerative disease of the eye that causes irreversible blindness. It is characterized by damage to the optic nerve, usually due to high intraocular pressure (IOP, and progressive degeneration of retinal neurons called retinal ganglion cells (RGCs. Current therapy for glaucoma focuses on reduction of IOP, but neuroprotection may also be beneficial. BDNF is a powerful neuroprotective agent especially for RGCs. Exogenous application of BDNF to the retina and increased BDNF expression in retinal neurons using viral vector systems are both effective in protecting RGCs from damage. Furthermore, induction of BDNF expression by agents such as valproic acid has also been beneficial in promoting RGC survival. In this review, we discuss the therapeutic potential of neurotrophic factors in retinal diseases and focus on the differential roles of glial and neuronal TrkB in neuroprotection. We also discuss the role of neurotrophic factors in neuroregeneration.

  12. Synaptic remodeling generates synchronous oscillations in the degenerated outer mouse retina

    Science.gov (United States)

    Haq, Wadood; Arango-Gonzalez, Blanca; Zrenner, Eberhart; Euler, Thomas; Schubert, Timm

    2014-01-01

    During neuronal degenerative diseases, neuronal microcircuits undergo severe structural alterations, leading to remodeling of synaptic connectivity. The functional consequences of such remodeling are mostly unknown. For instance, in mutant rd1 mouse retina, a common model for Retinitis Pigmentosa, rod bipolar cells (RBCs) establish contacts with remnant cone photoreceptors (cones) as a consequence of rod photoreceptor cell death and the resulting lack of presynaptic input. To assess the functional connectivity in the remodeled, light-insensitive outer rd1 retina, we recorded spontaneous population activity in retinal wholemounts using Ca2+ imaging and identified the participating cell types. Focusing on cones, RBCs and horizontal cells (HCs), we found that these cell types display spontaneous oscillatory activity and form synchronously active clusters. Overall activity was modulated by GABAergic inhibition from interneurons such as HCs and/or possibly interplexiform cells. Many of the activity clusters comprised both cones and RBCs. Opposite to what is expected from the intact (wild-type) cone-ON bipolar cell pathway, cone and RBC activity was positively correlated and, at least partially, mediated by glutamate transporters expressed on RBCs. Deletion of gap junctional coupling between cones reduced the number of clusters, indicating that electrical cone coupling plays a crucial role for generating the observed synchronized oscillations. In conclusion, degeneration-induced synaptic remodeling of the rd1 retina results in a complex self-sustained outer retinal oscillatory network, that complements (and potentially modulates) the recently described inner retinal oscillatory network consisting of amacrine, bipolar and ganglion cells. PMID:25249942

  13. Superficial peroneal nerve paresis in a dancer caused by a midfoot ganglion: case report.

    Science.gov (United States)

    Martin, Darrell; Dowling, Jamie; Rowan, Fiachra; Casey, Mary; O'Grady, Paul

    2015-06-01

    Ganglion cysts are common benign masses, usually occurring in the hands and feet. This report describes the case of a young female Irish dancer who presented with paresthesia of her foot due to a ganglion in near proximity to the superficial peroneal nerve. Midfoot ganglia in young girls engaged in Irish dance can limit their ability to participate. This pathology requires further epidemiological studies to investigate its prevalence. In the event of failed conservative management, surgical intervention to excise the cyst and decompress the nerve is an effective treatment to facilitate return to dancing.

  14. Basal ganglion calcification in hyperphenylalaninemia due to deficiency of dihydropteridine reductase

    International Nuclear Information System (INIS)

    Schmidt, H.; Ullrich, K.; Korinthenberg, R.; Peters, P.E.; Muenster Univ.

    1988-01-01

    The disease course and therapy of a nine-and-a-half-year-old boy with hyperphenylalaninemia due to a dihydropteridine reductase deficiency are reported. Clinicially, there is a marked mental retardation and complex basal ganglion symptoms. The cranial computer tomographic investigation shows bilateral, symmetrical, comma-shaped calcifications in the globus pallidus and the putamen of the lentiform nucleus. The cause of these basal ganglion calcifications remains unclear. Lowering of serum and CSF folic acid levels could not be detected, in contrast to cases with the same enzyme defect described previously. (orig.)

  15. Temporal response of protein-based artificial ganglion cell receptive field (Conference Presentation)

    Science.gov (United States)

    Okada-Shudo, Yoshiko

    2016-10-01

    We propose ganglion cell receptive-field-type filters with the use of the photoreceptor protein bacteriorhodopsin. Visual image processing is possible with the use of only one sensing element. We also demonstrate that our difference of Gaussians (DOG) filter, which mimics on-center off-suround ganglion cell receptive fields, has the function of a Laplacian filter and can act as an edge detecor. The X-type receptive field responses obtained by the filter, for a variety of stimuli, are compared with available electrophysiological recodings.

  16. MR imaging findings of neurosarcoidosis of the gasserian ganglion: an unusual presentation

    Energy Technology Data Exchange (ETDEWEB)

    Arias, Mercedes; Iglesias, Alfonso; Vila, Oscar; Brasa, Jose [Unidad de Resonancia Magnetica (MEDTEC), Hospital Xeral-Cies, 36204 Vigo (Spain); Conde, Cesareo [Servicio de Neurocirugia, Hospital Xeral-Cies, 36204 Vigo (Spain)

    2002-11-01

    We report the MR imaging findings of an unusual case of neurosarcoidosis of the gasserian ganglion associated with trigeminal neuralgia. No other neurological or extraneurological localization was found. Magnetic resonance imaging demonstrated a mass in the Meckel's diverticulum that was isointense on T1-weighted images and hypointense on T2-weighted images. Gadolinium-enhanced MR imaging showed heterogeneous enhancement. Although rare, sarcoid infiltration of the gasserian ganglion must be considered in the differential diagnosis of an isolated mass in this localization in patients with trigeminal neuralgia. (orig.)

  17. MR imaging findings of neurosarcoidosis of the gasserian ganglion: an unusual presentation

    International Nuclear Information System (INIS)

    Arias, Mercedes; Iglesias, Alfonso; Vila, Oscar; Brasa, Jose; Conde, Cesareo

    2002-01-01

    We report the MR imaging findings of an unusual case of neurosarcoidosis of the gasserian ganglion associated with trigeminal neuralgia. No other neurological or extraneurological localization was found. Magnetic resonance imaging demonstrated a mass in the Meckel's diverticulum that was isointense on T1-weighted images and hypointense on T2-weighted images. Gadolinium-enhanced MR imaging showed heterogeneous enhancement. Although rare, sarcoid infiltration of the gasserian ganglion must be considered in the differential diagnosis of an isolated mass in this localization in patients with trigeminal neuralgia. (orig.)

  18. Apathy in corticobasal degeneration: possible parietal involvement.

    Science.gov (United States)

    Moretti, Rita; Caberlotto, R; Signori, R

    Corticobasal degeneration is a rare disorder, which usually consists of a combination of complex movement disorders, apraxia and cortical changes. Its definition is still evolving and in 2013 an international consortium tried to develop new criteria, based on a systematic literature review. Over a long period of time, we carefully selected 23 patients who fulfilled the criteria for a diagnosis of corticobasal degeneration; all had the so-called corticobasal syndrome phenotype, in accordance with Armstrong et al. (2013). Through a dedicated study, we set out to study behavioral alterations, specifically apathy, and to compare the results obtained with those deriving from a well-defined Parkinson's disease population. On the basis of our limited but specific results, we argue for a possible role of the parietal neural networks as a determinant of apathy, and provide an overview of emerging data in the imaging and pathology literature.

  19. Inflammation in intervertebral disc degeneration and regeneration

    Science.gov (United States)

    Molinos, Maria; Almeida, Catarina R.; Caldeira, Joana; Cunha, Carla; Gonçalves, Raquel M.; Barbosa, Mário A.

    2015-01-01

    Intervertebral disc (IVD) degeneration is one of the major causes of low back pain, a problem with a heavy economic burden, which has been increasing in prevalence as populations age. Deeper knowledge of the complex spatial and temporal orchestration of cellular interactions and extracellular matrix remodelling is critical to improve current IVD therapies, which have so far proved unsatisfactory. Inflammation has been correlated with degenerative disc disease but its role in discogenic pain and hernia regression remains controversial. The inflammatory response may be involved in the onset of disease, but it is also crucial in maintaining tissue homeostasis. Furthermore, if properly balanced it may contribute to tissue repair/regeneration as has already been demonstrated in other tissues. In this review, we focus on how inflammation has been associated with IVD degeneration by describing observational and in vitro studies as well as in vivo animal models. Finally, we provide an overview of IVD regenerative therapies that target key inflammatory players. PMID:25673296

  20. Citral sensing by Transient [corrected] receptor potential channels in dorsal root ganglion neurons.

    Directory of Open Access Journals (Sweden)

    Stephanie C Stotz

    2008-05-01

    Full Text Available Transient receptor potential (TRP ion channels mediate key aspects of taste, smell, pain, temperature sensation, and pheromone detection. To deepen our understanding of TRP channel physiology, we require more diverse pharmacological tools. Citral, a bioactive component of lemongrass, is commonly used as a taste enhancer, as an odorant in perfumes, and as an insect repellent. Here we report that citral activates TRP channels found in sensory neurons (TRPV1 and TRPV3, TRPM8, and TRPA1, and produces long-lasting inhibition of TRPV1-3 and TRPM8, while transiently blocking TRPV4 and TRPA1. Sustained citral inhibition is independent of internal calcium concentration, but is state-dependent, developing only after TRP channel opening. Citral's actions as a partial agonist are not due to cysteine modification of the channels nor are they a consequence of citral's stereoisoforms. The isolated aldehyde and alcohol cis and trans enantiomers (neral, nerol, geranial, and geraniol each reproduce citral's actions. In juvenile rat dorsal root ganglion neurons, prolonged citral inhibition of native TRPV1 channels enabled the separation of TRPV2 and TRPV3 currents. We find that TRPV2 and TRPV3 channels are present in a high proportion of these neurons (94% respond to 2-aminoethyldiphenyl borate, consistent with our immunolabeling experiments and previous in situ hybridization studies. The TRPV1 activation requires residues in transmembrane segments two through four of the voltage-sensor domain, a region previously implicated in capsaicin activation of TRPV1 and analogous menthol activation of TRPM8. Citral's broad spectrum and prolonged sensory inhibition may prove more useful than capsaicin for allodynia, itch, or other types of pain involving superficial sensory nerves and skin.

  1. The role of intrinsically photosensitive retinal ganglion cells in nonimage-forming responses to light

    Directory of Open Access Journals (Sweden)

    Warthen DM

    2012-09-01

    Full Text Available Daniel M Warthen,1,2 Ignacio Provencio11Department of Biology, University of Virginia, Charlottesville, VA, USA; 2Department of Pharmacology, University of Virginia School of Medicine, Charlottesville, VA, USAAbstract: Light exerts many effects on behavior and physiology. These effects can be characterized as either image-forming or nonimage-forming (NIF visual processes. Image-forming vision refers to the process of detecting objects and organisms in the environment and distinguishing their physical characteristics, such as size, shape, and direction of motion. NIF vision, in contrast, refers to effects of light that are independent of fine spatiotemporal vision. NIF effects are many and varied, ranging from modulation of basal physiology, such as heart rate and body temperature, to changes in higher functions, such as mood and cognitive performance. In mammals, many NIF effects of light are dependent upon the inner retinal photopigment melanopsin and the cells in which melanopsin is expressed, the intrinsically photosensitive retinal ganglion cells (ipRGCs. The ipRGCs project broadly throughout the brain. Many of these projections terminate in areas known to mediate NIF effects, while others terminate in regions whose link to photoreception remains to be established. Additionally, the presence of ipRGC projections to areas of the brain with no known link to photoreception suggests the existence of additional ipRGC-mediated NIF effects. This review summarizes the known NIF effects of light and the role of melanopsin and ipRGCs in driving these effects, with an eye toward stimulating further investigation of the many and varied effects of light on physiology and behavior.Keywords: amygdala, bed nucleus of the stria terminalis, melanopsin, opsin, optic nerve, retina

  2. Purinergic transmission and transglial signaling between neuron somata in the dorsal root ganglion.

    Science.gov (United States)

    Rozanski, Gabriela M; Li, Qi; Kim, Hyunhee; Stanley, Elise F

    2013-02-01

    Most dorsal root ganglion neuronal somata (NS) are isolated from their neighbours by a satellite glial cell (SGC) sheath. However, some NS are associated in pairs, separated solely by the membrane septum of a common SGC to form a neuron-glial cell-neuron (NGlN) trimer. We reported that stimulation of one NS evokes a delayed, noisy and long-duration inward current in both itself and its passive partner that was blocked by suramin, a general purinergic antagonist. Here we test the hypothesis that NGlN transmission involves purinergic activation of the SGC. Stimulation of the NS triggered a sustained current noise in the SGC. Block of transmission through the NGlN by reactive blue 2 or thapsigargin, a Ca(2+) store-depletion agent, implicated a Ca(2+) store discharge-linked P2Y receptor. P2Y2 was identified by simulation of the NGlN-like transmission by puffing UTP onto the SGC and by immunocytochemical localization to the SGC membrane septum. Block of the UTP effect by BAPTA, an intracellular Ca(2+) scavenger, supported the involvement of SGC Ca(2+) stores in the signaling pathway. We infer that transmission through the NGlN trimer involves secretion of ATP from the NS and triggering of SGC Ca(2+) store discharge via P2Y2 receptors. Presumably, cytoplasmic Ca(2+) elevation leads to the release of an as-yet unidentified second transmitter from the glial cell to complete transmission. Thus, the two NS of the NGlN trimer communicate via a 'sandwich synapse' transglial pathway, a novel signaling mechanism that may contribute to information transfer in other regions of the nervous system. © 2012 Federation of European Neuroscience Societies and Blackwell Publishing Ltd.

  3. Degenerate odd Poisson bracket on Grassmann variables

    International Nuclear Information System (INIS)

    Soroka, V.A.

    2000-01-01

    A linear degenerate odd Poisson bracket (antibracket) realized solely on Grassmann variables is proposed. It is revealed that this bracket has at once three Grassmann-odd nilpotent Δ-like differential operators of the first, second and third orders with respect to the Grassmann derivatives. It is shown that these Δ-like operators, together with the Grassmann-odd nilpotent Casimir function of this bracket, form a finite-dimensional Lie superalgebra

  4. Degenerate RFID Channel Modeling for Positioning Applications

    Directory of Open Access Journals (Sweden)

    A. Povalac

    2012-12-01

    Full Text Available This paper introduces the theory of channel modeling for positioning applications in UHF RFID. It explains basic parameters for channel characterization from both the narrowband and wideband point of view. More details are given about ranging and direction finding. Finally, several positioning scenarios are analyzed with developed channel models. All the described models use a degenerate channel, i.e. combined signal propagation from the transmitter to the tag and from the tag to the receiver.

  5. Nerves are more abundant than blood vessels in the degenerate human intervertebral disc.

    Science.gov (United States)

    Binch, Abbie L A; Cole, Ashley A; Breakwell, Lee M; Michael, Antony L R; Chiverton, Neil; Creemers, Laura B; Cross, Alison K; Le Maitre, Christine L

    2015-12-21

    Chronic low back pain (LBP) is the most common cause of disability worldwide. New ideas surrounding LBP are emerging that are based on interactions between mechanical, biological and chemical influences on the human IVD. The degenerate IVD is proposed to be innervated by sensory nerve fibres and vascularised by blood vessels, and it is speculated to contribute to pain sensation. However, the incidence of nerve and blood vessel ingrowth, as well as whether these features are always associated, is unknown. We investigated the presence of nerves and blood vessels in the nucleus pulposus (NP) of the IVD in a large population of human discs. Immunohistochemistry was performed with 61 human IVD samples, to identify and localise nerves (neurofilament 200 [NF200]/protein gene product 9.5) and blood vessels (CD31) within different regions of the IVD. Immunopositivity for NF200 was identified within all regions of the IVD within post-mortem tissues. Nerves were seen to protrude across lamellar ridges and through matrix towards NP cells. Nerves were identified deep within the NP and were in many cases, but not always, seen in close proximity to fissures or in areas where decreased matrix was seen. Fifteen percent of samples were degenerate and negative for nerves and blood vessels, whilst 16 % of all samples were degenerate with nerves and blood vessels. We identified 52% of samples that were degenerate with nerves but no blood vessels. Interestingly, only 4% of all samples were degenerate with no nerves but positive for blood vessels. Of the 85 samples investigated, only 6 % of samples were non-degenerate without nerves and blood vessels and 7% had nerves but no blood vessels. This study addresses the controversial topic of nerve and blood vessel ingrowth into the IVD in a large number of human samples. Our findings demonstrate that nerves are present within a large proportion of NP samples from degenerate IVDs. This study shows a possible link between nerve ingrowth and

  6. Can Neutrinos be Degenerate in Mass?

    CERN Document Server

    Ellis, Jonathan Richard; Ellis, John; Lola, Smaragda

    1999-01-01

    We reconsider the possibility that the masses of the three light neutrinos of the Standard Model might be almost degenerate and close to the present upper limits from Tritium beta decay and cosmology. In such a scenario, the cancellations required by the latest upper limit on neutrinoless double-beta decay enforce near-maximal mixing that may be compatible only with the vacuum-oscillation scenario for solar neutrinos. We argue that the mixing angles yielded by degenerate neutrino mass-matrix textures are not in general stable under small perturbations. We evaluate within the MSSM the generation-dependent one-loop renormalization of neutrino mass-matrix textures that yielded degenerate masses and large mixing at the tree level. We find that m_{nu_e} > m_{nu_mu} > m_{nu_tau} after renormalization, excluding MSW effects on solar neutrinos. We verify that bimaximal mixing is not stable, and show that the renormalized masses and mixing angles are not compatible with all the experimental constraints, even for tanbe...

  7. Degenerate pressure driven modified nucleus-acoustic waves in degenerate plasmas

    Science.gov (United States)

    Mamun, A. A.

    2018-02-01

    The existence of degenerate pressure driven modified nucleus-acoustic (DPDMNA) waves propagating in a cold degenerate quantum plasma (DQP) system [containing cold inertialess degenerate electron species (DES), cold inertial non-degenerate light nucleus species (LNS), and stationary heavy nucleus species (HNS)] is predicted for the first time. The DPDMNA waves (in which the mass density of the cold LNS provides the inertia and the cold inertialess DES gives rise to the restoring force) are new since they completely disappear if the degenerate pressure of the cold DES is neglected. It is found that the phase speed (Vp) of the DPDMNA waves decreases with the rise of the charge number density of the stationary HNS for both non-relativistic and ultra-relativistic DES, and that the ultra-relativistic DES does not have any effect on Vp when β = 1, where β = Λc/Λe with Λ e = ne 0 - 1 / 3 being the average inter-electron distance in the DQP system and Λc being the constant (˜10-10 cm) for the DES. However, the ultra-relativistic DES does have quite a significant effect on Vp for β ≫ 1 and β ≪ 1, and the ultra-relativistic effect significantly enhances (reduces) Vp for β ≫ 1 (β ≪ 1). The DPDMNA waves and their dispersion properties are expected to be useful in understanding the basic features of the electrostatic perturbation mode in space and laboratory DQP systems.

  8. 1995 Volvo Award in clinical sciences. Determinants of lumbar disc degeneration. A study relating lifetime exposures and magnetic resonance imaging findings in identical twins.

    Science.gov (United States)

    Battié, M C; Videman, T; Gibbons, L E; Fisher, L D; Manninen, H; Gill, K

    1995-12-15

    Retrospective cohort. To investigate the effects of lifetime exposure to commonly suspected risk factors on disc degeneration using magnetic resonance imaging, and to estimate the effects of these suspected risk factors relative to age and familial aggregation, reflecting genetic and shared environmental influences. Structural and biochemical changes associated with disc degeneration are suspected as the underlying conditions of many back-related symptoms. Little is known about the determinants of disc degeneration. Based on lifetime discordance in suspected environmental risk factors for disc degeneration, 115 male identical twin pairs were selected. An in-depth interview was conducted of occupational and leisure time physical loading, driving, and smoking. Disc degeneration was evaluated using observational and digital magnetic resonance imaging assessment methods. Heavier lifetime occupational and leisure physical loading was associated with greater disc degeneration in the upper lumbar levels (P = 0.055 - 0.001), whereas sedentary work was associated with lesser degeneration (P = 0.006). These univariate associations did not reach statistical significance in the lower lumbar region. In multivariate analyses of the upper lumbar levels, the mean job code explained 7% of the variability in observational disc degeneration scores; the addition of age explained 16%, and familial aggregation improved the model such that 77% of the variability was explained. In the lower lumbar levels, leisure time physical loading entered the multivariate model, explaining 2% of the variability. Adding age explained 9%, and familial aggregation raised the variability in disc degeneration scores explained to 43%. The present study findings suggest that disc degeneration may be explained primarily by genetic influences and by unidentified factors, which may include complex, unpredictable interactions. The particular environmental factors studied, which have been among those most widely

  9. Specific spatio-temporal activities in the cerebral ganglion of Incilaria fruhstorferi in response to superior and inferior tentacle nerve stimulation.

    Science.gov (United States)

    Makinae, Hisanori; Makino, Yoshinari; Obara, Tsukasa; Yano, Masafumi

    2008-09-22

    In terrestrial gastropod mollusks (slugs and snails), olfaction is the dominant sensory modality guiding various kinds of behavior. Anatomical studies indicate that olfactory information is processed in the brain (the cerebral ganglion) in two lobes in particular: the procerebrum (PC) and the metacerebrum (MtC). This implies that olfactory functions emerge from simultaneous and cooperative processing in the PC and the MtC. However, no previous physiological study has investigated the activity in these two lobes simultaneously. In the present study, the activity evoked by electrical stimulation of the olfactory nerves, the superior and inferior tentacle nerves, was recorded optically from the whole cerebral ganglion of the terrestrial slug, Incilaria fruhstorferi. The results indicated that the evoked activity in the PC and the MtC showed two specific spatio-temporal patterns. First, when either set of nerves was stimulated, the activity of the medial neuropilar region of the MtC (the mMtC) always preceded the activity in the PC. Second, stimulation of the superior tentacle nerves activated the medial and lateral halves of the mMtC almost evenly, whereas stimulation of the inferior tentacle nerves activated the lateral half of the mMtC more strongly than the medial half. These results suggest that the activated region of the mMtC plays an important role in olfactory processing, especially with respect to the functional differences between the superior and inferior tentacles.

  10. Altered neurotransmitter expression profile in the ganglionic bowel in Hirschsprung's disease.

    Science.gov (United States)

    Coyle, David; O'Donnell, Anne Marie; Gillick, John; Puri, Prem

    2016-05-01

    Despite having optimal pull-through (PT) surgery for Hirschsprung's disease (HSCR), many patients experience persistent bowel symptoms with no mechanical/histopathological cause. Murine models of HSCR suggest that expression of key neurotransmitters is unbalanced proximal to the aganglionic colonic segment. We aimed to investigate expression of key enteric neurotransmitters in the colon of children with HSCR. Full-length PT specimens were collected fresh from children with HSCR (n=10). Control specimens were collected at colostomy closure from children with anorectal malformation (n=8). The distributions of neuronal nitric oxide synthase (nNOS), choline acetyltransferase (ChAT), vasoactive intestinal peptide (VIP), and substance P (SP) were evaluated using immunofluorescence and confocal microscopy. Neurotransmitter quantification was with Western blot analysis. ChAT expression was high in aganglionic bowel and transition zone but reduced in ganglionic bowel in HSCR relative to controls. Conversely, nNOS expression was markedly reduced in aganglionic bowel but high in ganglionic bowel in HSCR relative to controls. VIP expression was similar in ganglionic HSCR and control colon. SP expression was similar in all tissue types. Imbalance of key excitatory and inhibitory neurotransmitters in the ganglionic bowel in HSCR may explain the basis of bowel dysmotility after an optimal pull-through operation in some patients. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. [Vimentin and S100 protein in the developing rat dorsal root ganglion cells].

    Science.gov (United States)

    Kolos, Ye A; Korzhevskiy, D E

    2013-01-01

    The aim of this research was to study the expression of vimentin, one of the intermediate filament proteins, and S100 protein in the cells of developing dorsal root ganglion in prenatal ontogenesis in Wistar rat embryos (n=22) on 12-19 days of development and in newborn rats (n=6). Immunohistochemical staining methods were used to study the formation of rat dorsal root ganglion glial cells. Vimentin-immunopositive neural and glial progenitor cells were present in dorsal root ganglion primordia in rat embryos at 12-17 prenatal days. At the later stages (day 19 of prenatal life and day 1 of postnatal life) vimentin was found to be synthesized only by the differentiating glial cells. It was shown that at the same time, S100 protein was first detected in the glial cells of rat dorsal root ganglion. On postnatal day 1, the tendency was noted for the accumulation of S100 protein in the larger neurons, that was characteristic to mature dorsal root ganglia.

  12. Modulation of inflammatory mediators in the trigeminal ganglion by botulinum neurotoxin type A

    DEFF Research Database (Denmark)

    Edvinsson, Jacob; Warfvinge, Karin; Edvinsson, Lars

    2015-01-01

    BACKGROUND: Onabotulinumtoxin type A (BoNT-A) has been found to reduce pain in chronic migraine. The aim of the present study was to ask if BoNT-A can interact directly on sensory mechanisms in the trigeminal ganglion (TG) using an organ culture method. METHODS: To induce inflammation, rat TGs we...

  13. Coccygodynia treated by pulsed radio frequency treatment to the Ganglion of Impar: a case series.

    Science.gov (United States)

    Gopal, Hari; Mc Crory, Connail

    2014-01-01

    Chronic coccygodynia accounts for 1% of all back pain referrals and very difficult to treat with an enormous functional deficit. The purpose of this case series was to examine the effectiveness of pulsed radiofrequency treatment to the Ganglion of Impar in chronic coccygodynia patients unresponsive to comprehensive medical management. Coccygodynia is defined as pain in and around the coccyx [1,2]. This retrospective review of twenty patients with a clinical diagnosis of coccygodynia and failed medical management treated with pulsed radio frequency applied to the Ganglion of Impar between January 2009 to December 2011 was carried out. A successful outcome was defined as > 50% improvement in pain on the visual analogue scale at 6 and 12 months follow-up. The application of pulsed radio frequency to the Ganglion of Impar was successful in fifteen (75%) patients and their mean pre treatment visual analogue scale score of 6.53 was reduced to 0.93 at 6 and 12 months follow up. In five (25%) patients the treatment was not successful and there was no difference between mean pre and post treatment visual analogue scale scores. We conclude that pulsed radio frequency treatment of the Ganglion of Impar should be considered when coccygodynia has proven resistant to medical management.

  14. Pain Relief due to Transsacrococcygeal Ganglion Impar Block in Chronic Coccygodynia: A Pilot Study.

    Science.gov (United States)

    Gunduz, Osman Hakan; Sencan, Savas; Kenis-Coskun, Ozge

    2015-07-01

    Coccygodynia is a distressing condition that presents with pain around the coccyx. Impar (Walther) ganglion is a sympathetic ganglion located at the end of lumbosacral sympathetic chain. The objective of this study is to share our results and follow up of 34 ganglion impar blocks in 22 patients. Retrospective pilot study. Interventional Pain Clinic in the Department of Physical Medicine and Rehabilitation in a university hospital. Twenty-two patients with coccygodynia who did not respond to conservative treatment and then presented to interventional pain clinic of a PM&R department in a university hospital Pain was evaluated via 10-cm visual analog scale (VAS). VAS values were obtained before, 1 hour and 3 weeks after injection and during this study was conducted. For achieving at least 50% relief of pain, the success rate of a first injection was 82%, but accounted for three technical failures. In patients with a successful outcome, relief lasted for a median duration of 6 months. Relief was reinstated for a median period of 17 months by a second injection in nine patients who presented for repeat treatment. No relief was achieved in two of these patients when they presented for a third treatment. Ganglion impar block appears to be effective in patients who have coccygodynia resistant to conservative therapy, with high success rates and prolonged duration of effect. Controlled studies are required to reveal the mechanism of this effect. Wiley Periodicals, Inc.

  15. Visual Field Defects and Retinal Ganglion Cell Losses in Human Glaucoma Patients

    Science.gov (United States)

    Harwerth, Ronald S.; Quigley, Harry A.

    2007-01-01

    Objective The depth of visual field defects are correlated with retinal ganglion cell densities in experimental glaucoma. This study was to determine whether a similar structure-function relationship holds for human glaucoma. Methods The study was based on retinal ganglion cell densities and visual thresholds of patients with documented glaucoma (Kerrigan-Baumrind, et al.) The data were analyzed by a model that predicted ganglion cell densities from standard clinical perimetry, which were then compared to histologic cell counts. Results The model, without free parameters, produced accurate and relatively precise quantification of ganglion cell densities associated with visual field defects. For 437 sets of data, the unity correlation for predicted vs. measured cell densities had a coefficient of determination of 0.39. The mean absolute deviation of the predicted vs. measured values was 2.59 dB, the mean and SD of the distribution of residual errors of prediction was -0.26 ± 3.22 dB. Conclusions Visual field defects by standard clinical perimetry are proportional to neural losses caused by glaucoma. Clinical Relevance The evidence for quantitative structure-function relationships provides a scientific basis of interpreting glaucomatous neuropathy from visual thresholds and supports the application of standard perimetry to establish the stage of the disease. PMID:16769839

  16. Sphenopalatine ganglion stimulation for cluster headache, results from a large, open-label European registry

    DEFF Research Database (Denmark)

    Barloese, Mads; Petersen, Anja; Stude, Philipp

    2018-01-01

    ganglion (SPG) stimulation. METHODS: Patients were followed in an open-label prospective study for 12 months. Ninety-seven CH patients (88 chronic, 9 episodic) underwent trans-oral insertion of a microstimulator targeting the SPG. Patients recorded stimulation effect prospectively for individual attacks...

  17. Retinal ganglion cell neuroprotection by an angiotensin II blocker in an ex vivo retinal explant model.

    Science.gov (United States)

    White, Andrew J R; Heller, Janosch P; Leung, Johahn; Tassoni, Alessia; Martin, Keith R

    2015-12-01

    An ex vivo organotypic retinal explant model was developed to examine retinal survival mechanisms relevant to glaucoma mediated by the renin angiotensin system in the rodent eye. Eyes from adult Sprague Dawley rats were enucleated immediately post-mortem and used to make four retinal explants per eye. Explants were treated either with irbesartan (10 µM), vehicle or angiotensin II (2 μM) for four days. Retinal ganglion cell density was estimated by βIII tubulin immunohistochemistry. Live imaging of superoxide formation with dihydroethidium (DHE) was performed. Protein expression was determined by Western blotting, and mRNA expression was determined by RT-PCR. Irbesartan (10 µM) almost doubled ganglion cell survival after four days. Angiotensin II (2 µM) reduced cell survival by 40%. Sholl analysis suggested that irbesartan improved ganglion cell dendritic arborisation compared to control and angiotensin II reduced it. Angiotensin-treated explants showed an intense DHE fluorescence not seen in irbesartan-treated explants. Analysis of protein and mRNA expression determined that the angiotensin II receptor At1R was implicated in modulation of the NADPH-dependent pathway of superoxide generation. Angiotensin II blockers protect retinal ganglion cells in this model and may be worth further investigation as a neuroprotective treatment in models of eye disease. © The Author(s) 2015.

  18. Loss of Melanopsin-Expressing Retinal Ganglion Cells in Patients With Diabetic Retinopathy

    DEFF Research Database (Denmark)

    Obara, Elisabeth Anne; Hannibal, Jens; Heegaard, Steffen

    2017-01-01

    Purpose: Photo-entrainment of the circadian clock is mediated by melanopsin-expressing retinal ganglion cells (mRGCs) located in the retina. Patients suffering from diabetic retinopathy (DR) show impairment of light regulated circadian activity such as sleep disorders, altered blood pressure...

  19. MRI diagnosis of soft ganglion cyst in the foot and ankle

    International Nuclear Information System (INIS)

    Zhang Zhaohui; Liang Manqiu; Li Zhuhao

    2011-01-01

    Objective: To explore the clinical and MR imaging features of soft tissue ganglion cyst in the foot and ankle. Methods: Clinical and MR imaging data of 12 patients (male to female ratio 1:5, mean age 47 years) with soft tissue ganglion cysts in the feet and ankles were retrospectively analyzed. Results: The 12 ganglion cysts were located near the first metatarsophalangeal joint (2), in the medial dorsum of foot (4), in the ankle (5) and in the heel (1). Compared with muscle, all lesions showed homogeneous slight T 1 hypointensity and T 2 hyperintensity with thin mural enhancement following the injection of Gd-DTPA. Ten cases were multilocular, and 5 showed mild pericystic edema. Conclusion: Soft tissue ganglion cyst of the foot and ankle are more common in middle aged women. They are frequently located in the ankle and medial dorsum of foot. On MRI they usually appear as multilocular cysts with homogeneous slightly low signal intensity relative to muscle on T 1 WI, high signal intensity on T 2 WI and contrast enhancement of the thin wall. (authors)

  20. Melanopsin retinal ganglion cells are resistant to neurodegeneration in mitochondrial optic neuropathies

    DEFF Research Database (Denmark)

    La Morgia, C; Ross-Cisneros, F.N.; Sadun, A.A.

    2010-01-01

    Mitochondrial optic neuropathies, that is, Leber hereditary optic neuropathy and dominant optic atrophy, selectively affect retinal ganglion cells, causing visual loss with relatively preserved pupillary light reflex. The mammalian eye contains a light detection system based on a subset of retina...

  1. Rabies virus infection of cultured adult mouse dorsal root ganglion neurons

    Directory of Open Access Journals (Sweden)

    Jaime Castellanos

    1996-10-01

    Full Text Available An in vitro model of adult dorsal root ganglion neurons infection by rabies virus is described. Viral marked neurotropism is observed, and the percentage and the degree of infection of the neurons is higher than in non neuronal cells, even if neurons are the minority of the cells in the culture. The neuritic tree is also heavily infected by the virus.

  2. Neuronal injury external to the retina rapidly activates retinal glia, followed by elevation of markers for cell cycle re-entry and death in retinal ganglion cells.

    Directory of Open Access Journals (Sweden)

    Alba Galan

    Full Text Available Retinal ganglion cells (RGCs are neurons that relay visual signals from the retina to the brain. The RGC cell bodies reside in the retina and their fibers form the optic nerve. Full transection (axotomy of the optic nerve is an extra-retinal injury model of RGC degeneration. Optic nerve transection permits time-kinetic studies of neurodegenerative mechanisms in neurons and resident glia of the retina, the early events of which are reported here. One day after injury, and before atrophy of RGC cell bodies was apparent, glia had increased levels of phospho-Akt, phospho-S6, and phospho-ERK1/2; however, these signals were not detected in injured RGCs. Three days after injury there were increased levels of phospho-Rb and cyclin A proteins detected in RGCs, whereas these signals were not detected in glia. DNA hyperploidy was also detected in RGCs, indicative of cell cycle re-entry by these post-mitotic neurons. These events culminated in RGC death, which is delayed by pharmacological inhibition of the MAPK/ERK pathway. Our data show that a remote injury to RGC axons rapidly conveys a signal that activates retinal glia, followed by RGC cell cycle re-entry, DNA hyperploidy, and neuronal death that is delayed by preventing glial MAPK/ERK activation. These results demonstrate that complex and variable neuro-glia interactions regulate healthy and injured states in the adult mammalian retina.

  3. Anti-tubulin labeling reveals ampullary neuron ciliary bundles in opisthobranch larvae and a new putative neural structure associated with the apical ganglion.

    Science.gov (United States)

    Kempf, Stephen C; Page, Louise R

    2005-06-01

    This investigation examines tubulin labeling associated with the apical ganglion in a variety of planktotrophic and lecithotrophic opisthobranch larvae. Emphasis is on the ampullary neurons, in which ciliary bundles within the ampulla are strongly labeled. The larvae of all but one species have five ampullary neurons and their associated ciliary bundles. The anaspid Phyllaplysia taylori, a species with direct development and an encapsulated veliger stage, has only four ampullary neurons. The cilia-containing ampulla extends to the pretrochal surface via a long, narrow canal that opens to the external environment through a very small pore (0.1 microm diameter). Cilia within the canal were never observed to project beyond the opening of the apical pore. The ampullary canals extend toward and are grouped with the ciliary tuft cells and remain in this location as planktotrophic larvae feed and grow. If, as has been reported, the ciliary tuft is motile, the pores may be continually bathed in fresh seawater. Such an arrangement would increase sensitivity to environmental chemical stimuli if the suggested chemosensory function of these neurons is correct. In general, ciliary bundles of newly hatched veligers are smaller in planktotrophic larvae than in lecithotrophic larvae. In planktotrophic larvae of Melibe leonina, the ciliary bundles increase in length and width as the veligers feed and grow. This may be related to an increase in sensitivity for whatever sensory function these neurons fulfill. An unexpected tubulin-labeled structure, tentatively called the apical nerve, was also found to be associated with the apical ganglion. This putative nerve extends from the region of the visceral organs to a position either within or adjacent to the apical ganglion. One function of the apical nerve might be to convey the stimulus resulting from metamorphic induction to the visceral organs.

  4. Common variants in the COL4A4 gene confer susceptibility to lattice degeneration of the retina.

    Science.gov (United States)

    Meguro, Akira; Ideta, Hidenao; Ota, Masao; Ito, Norihiko; Ideta, Ryuichi; Yonemoto, Junichi; Takeuchi, Masaki; Uemoto, Riyo; Nishide, Tadayuki; Iijima, Yasuhito; Kawagoe, Tatsukata; Okada, Eiichi; Shiota, Tomoko; Hagihara, Yuta; Oka, Akira; Inoko, Hidetoshi; Mizuki, Nobuhisa

    2012-01-01

    Lattice degeneration of the retina is a vitreoretinal disorder characterized by a visible fundus lesion predisposing the patient to retinal tears and detachment. The etiology of this degeneration is still uncertain, but it is likely that both genetic and environmental factors play important roles in its development. To identify genetic susceptibility regions for lattice degeneration of the retina, we performed a genome-wide association study (GWAS) using a dense panel of 23,465 microsatellite markers covering the entire human genome. This GWAS in a Japanese cohort (294 patients with lattice degeneration and 294 controls) led to the identification of one microsatellite locus, D2S0276i, in the collagen type IV alpha 4 (COL4A4) gene on chromosome 2q36.3. To validate the significance of this observation, we evaluated the D2S0276i region in the GWAS cohort and in an independent Japanese cohort (280 patients and 314 controls) using D2S0276i and 47 single nucleotide polymorphisms covering the region. The strong associations were observed in D2S0276i and rs7558081 in the COL4A4 gene (Pc = 5.8 × 10(-6), OR = 0.63 and Pc = 1.0 × 10(-5), OR = 0.69 in a total of 574 patients and 608 controls, respectively). Our findings suggest that variants in the COL4A4 gene may contribute to the development of lattice degeneration of the retina.

  5. Common variants in the COL4A4 gene confer susceptibility to lattice degeneration of the retina.

    Directory of Open Access Journals (Sweden)

    Akira Meguro

    Full Text Available Lattice degeneration of the retina is a vitreoretinal disorder characterized by a visible fundus lesion predisposing the patient to retinal tears and detachment. The etiology of this degeneration is still uncertain, but it is likely that both genetic and environmental factors play important roles in its development. To identify genetic susceptibility regions for lattice degeneration of the retina, we performed a genome-wide association study (GWAS using a dense panel of 23,465 microsatellite markers covering the entire human genome. This GWAS in a Japanese cohort (294 patients with lattice degeneration and 294 controls led to the identification of one microsatellite locus, D2S0276i, in the collagen type IV alpha 4 (COL4A4 gene on chromosome 2q36.3. To validate the significance of this observation, we evaluated the D2S0276i region in the GWAS cohort and in an independent Japanese cohort (280 patients and 314 controls using D2S0276i and 47 single nucleotide polymorphisms covering the region. The strong associations were observed in D2S0276i and rs7558081 in the COL4A4 gene (Pc = 5.8 × 10(-6, OR = 0.63 and Pc = 1.0 × 10(-5, OR = 0.69 in a total of 574 patients and 608 controls, respectively. Our findings suggest that variants in the COL4A4 gene may contribute to the development of lattice degeneration of the retina.

  6. Elevated Fractalkine (CX3CL1) Levels in the Trigeminal Ganglion Mechanically Sensitize Temporalis Muscle Nociceptors.

    Science.gov (United States)

    Cairns, Brian E; O'Brien, Melissa; Dong, Xu-Dong; Gazerani, Parisa

    2017-07-01

    It has been proposed that after nerve injury or tissue inflammation, fractalkine (CX3CL1) released from dorsal root ganglion neurons acts on satellite glial cells (SGCs) through CX3C receptor 1 (CX3CR1) to induce neuroplastic changes. The existence and importance of fractalkine/CX3CR1 signaling in the trigeminal ganglia has not yet been clarified. This study investigated (1) whether trigeminal ganglion neurons that innervate temporalis muscle and their associated SGCs contain fractalkine and/or express CX3CR1, (2) if intraganglionic injection of fractalkine increases the mechanical sensitivity of temporalis muscle afferent fibers, (3) whether complete Freund's adjuvant (CFA)-induced inflammation of the temporalis muscle alters the expression of fractalkine or its receptor in the trigeminal ganglion, and (4) if intraganglionic administration of CX3CR1 antibodies alters afferent mechanical sensitivity. Immunohistochemistry and in vivo electrophysiological recordings in male and female rats were used to address these questions. It was found that ∼50 % of temporalis ganglion neurons and ∼25 % of their associated SGCs express CX3CR1, while only neurons expressed fractalkine. Temporalis muscle inflammation increased the expression of fractalkine, but only in male rats. Intraganglionic injection of fractalkine (25 g/ml; 3 μl) induced prolonged afferent mechanical sensitization. Intraganglionic injection of CX3CR1 antibody increased afferent mechanical threshold, but this effect was greater in controls than in rats with CFA-induced muscle inflammation. These findings raise the possibility that basal fractalkine signalling within the trigeminal ganglion plays an important role in mechanical sensitivity of masticatory muscle sensory afferent fibers and that inhibition of CX3CR1 signaling within the trigeminal ganglia may induce analgesia through a peripheral mechanism.

  7. Clinical value of a self-designed training model for pinpointing and puncturing trigeminal ganglion.

    Science.gov (United States)

    He, Yu-Quan; He, Shu; Shen, Yun-Xia; Qian, Cheng

    2014-04-01

    OBJECTIVES. A training model was designed for learners and young physicians to polish their skills in clinical practices of pinpointing and puncturing trigeminal ganglion. METHODS. A head model, on both cheeks of which the deep soft tissue was replaced by stuffed organosilicone and sponge while the superficial soft tissue, skin and the trigeminal ganglion were made of organic silicon rubber for an appearance of real human being, was made from a dried skull specimen and epoxy resin. Two physicians who had experiences in puncturing foramen ovale and trigeminal ganglion were selected to test the model, mainly for its appearance, X-ray permeability, handling of the puncture, and closure of the puncture sites. Four inexperienced physicians were selected afterwards to be trained combining Hartel's anterior facial approach with the new method of real-time observation on foramen ovale studied by us. RESULTS. Both appearance and texture of the model were extremely close to those of a real human. The fact that the skin, superficial soft tissue, deep muscles of the cheeks, and the trigeminal ganglion made of organic silicon rubber all had great elasticity resulted in quick closure and sealing of the puncture sites. The head model made of epoxy resin had similar X-ray permeability to a human skull specimen under fluoroscopy. The soft tissue was made of radiolucent material so that the training can be conducted with X-ray guidance. After repeated training, all the four young physicians were able to smoothly and successfully accomplish the puncture. CONCLUSION. This self-made model can substitute for cadaver specimen in training learners and young physicians on foramen ovale and trigeminal ganglion puncture. It is very helpful for fast learning and mastering this interventional operation skill, and the puncture accuracy can be improved significantly with our new method of real-time observation on foramen ovale.

  8. Diabetes mellitus-related morphoquantitative changes in the celiac ganglion neurons of the dog.

    Science.gov (United States)

    Guidi, W L; Balieiro, J C C; De Souza, R R; Loesch, A; Ribeiro, A A C M

    2008-07-01

    Diabetes mellitus is the most common endocrine disturbance of domestic carnivores and can cause autonomic neurological disorders, although these are still poorly understood in veterinary medicine. There is little information available on the quantitative adaptation mechanisms of the sympathetic ganglia during diabetes mellitus in domestic mammals. By combining morphometric methods and NADPH-diaphorase staining (as a possible marker for nitric oxide producing neurons), type I diabetes mellitus-related morphoquantitative changes were investigated in the celiac ganglion neurons in dogs. Twelve left celiac ganglia from adult female German shepherd dogs were examined: six ganglia were from non-diabetic and six from diabetic subjects. Consistent hypertrophy of the ganglia was noted in diabetic animals with increase of 55% in length, 53% in width, and 61.5% in thickness. The ordinary microstructure of the ganglia was modified leading to an uneven distribution of the ganglionic units and a more evident distribution of axon fascicles. In contrast to non-diabetic dogs, there was a lack of NADPH-diaphorase perikarial labelling in the celiac ganglion neurons of diabetic animals. The morphometric study showed that both the neuronal and nuclear sizes were significantly larger in diabetic dogs (1.3 and 1.39 times, respectively). The profile density and area fraction of NADPH-diaphorase-reactive celiac ganglion neurons were significantly larger (1.35 and 1.48 times, respectively) in non-diabetic dogs compared to NADPH-diaphorase-non-reactive celiac ganglion neurons in diabetic dogs. Although this study suggests that diabetic neuropathy is associated with neuronal hypertrophy, controversy remains over the possibility of ongoing neuronal loss and the functional interrelationship between them. It is unclear whether neuronal hypertrophy could be a compensation mechanism for a putative neuronal loss during the diabetes mellitus.

  9. Molecular imaging of serotonin degeneration in mild cognitive impairment.

    Science.gov (United States)

    Smith, Gwenn S; Barrett, Frederick S; Joo, Jin Hui; Nassery, Najlla; Savonenko, Alena; Sodums, Devin J; Marano, Christopher M; Munro, Cynthia A; Brandt, Jason; Kraut, Michael A; Zhou, Yun; Wong, Dean F; Workman, Clifford I

    2017-09-01

    Neuropathological and neuroimaging studies have consistently demonstrated degeneration of monoamine systems, especially the serotonin system, in normal aging and Alzheimer's disease. The evidence for degeneration of the serotonin system in mild cognitive impairment is limited. Thus, the goal of the present study was to measure the serotonin transporter in vivo in mild cognitive impairment and healthy controls. The serotonin transporter is a selective marker of serotonin terminals and of the integrity of serotonin projections to cortical, subcortical and limbic regions and is found in high concentrations in the serotonergic cell bodies of origin of these projections (raphe nuclei). Twenty-eight participants with mild cognitive impairment (age 66.6±6.9, 16 males) and 28 healthy, cognitively normal, demographically matched controls (age 66.2±7.1, 15 males) underwent magnetic resonance imaging for measurement of grey matter volumes and high-resolution positron emission tomography with well-established radiotracers for the serotonin transporter and regional cerebral blood flow. Beta-amyloid imaging was performed to evaluate, in combination with the neuropsychological testing, the likelihood of subsequent cognitive decline in the participants with mild cognitive impairment. The following hypotheses were tested: 1) the serotonin transporter would be lower in mild cognitive impairment compared to controls in cortical and limbic regions, 2) in mild cognitive impairment relative to controls, the serotonin transporter would be lower to a greater extent and observed in a more widespread pattern than lower grey matter volumes or lower regional cerebral blood flow and 3) lower cortical and limbic serotonin transporters would be correlated with greater deficits in auditory-verbal and visual-spatial memory in mild cognitive impairment, not in controls. Reduced serotonin transporter availability was observed in mild cognitive impairment compared to controls in cortical and limbic

  10. Aneutronic Fusion in a Degenerate Plasma

    International Nuclear Information System (INIS)

    Son, S.; Fisch, N.J.

    2004-01-01

    In a Fermi-degenerate plasma, the electronic stopping of a slow ion is smaller than that given by the classical formula, because some transitions between the electron states are forbidden. The bremsstrahlung losses are then smaller, so that the nuclear burning of an aneutronic fuel is more efficient. Consequently, there occurs a parameter regime in which self-burning is possible. Practical obstacles in this regime that must be overcome before net energy can be realized include the compression of the fuel to an ultra dense state and the creation of a hot spot

  11. Malignant degeneration in neurofibromatosis: 3 case report

    International Nuclear Information System (INIS)

    Lee, Jong Moon; Kang, Eun Young; Lee, Nam Joon; Chung, Kyoo Byung; Suh, Won Hyuck

    1989-01-01

    Von Recklinghausen's nuerofilbromatosis is a kind of neurocutaneous syndrome characterized by skin, nervous system, neuromusculoskeletal manifestations. Most central and peripheral nervous neoplastic lesions in neurofibromatosis are benign but have a significant potential for malignant transformation such as neurofibrosarcoma, neurogenic sarcoma, malignant schwannoma. And it is relatively common disorder but malignant change with radiologic findings has been reported rarely in Korea. Recently we experienced three cases of malignant degeneration in neurofibromatosis and confirmed by pathology. So we report the cases with review including radiologic findings

  12. Aneutronic Fusion in a Degenerate Plasma

    Energy Technology Data Exchange (ETDEWEB)

    S. Son; N.J. Fisch

    2004-09-03

    In a Fermi-degenerate plasma, the electronic stopping of a slow ion is smaller than that given by the classical formula, because some transitions between the electron states are forbidden. The bremsstrahlung losses are then smaller, so that the nuclear burning of an aneutronic fuel is more efficient. Consequently, there occurs a parameter regime in which self-burning is possible. Practical obstacles in this regime that must be overcome before net energy can be realized include the compression of the fuel to an ultra dense state and the creation of a hot spot.

  13. MRI and MR tractography in bilateral hypertrophic olivary degeneration

    International Nuclear Information System (INIS)

    Sen, Debraj; Gulati, Yoginder S.; Malik, Virender; Mohimen, Aneesh; Sibi, Eranki; Reddy, Deepak Chandra

    2014-01-01

    Hypertrophic olivary degeneration is a trans-synaptic neuronal degeneration associated with hypertrophy of the inferior olivary nucleus due to a lesion in the triangle of Guillain-Mollaret. Familiarity with this entity on magnetic resonance imaging (MRI) is essential to avoid other erroneous ominous diagnoses. We present a case of bilateral hypertrophic olivary degeneration and discuss the etiopathogenesis and MRI findings in this entity. The contributory role of MR tractography in the diagnosis is also highlighted

  14. An Unusual Case of Extensive Lattice Degeneration and Retinal Detachment

    OpenAIRE

    Mathew, David J.; Sarma, Saurabh Kumar; Basaiawmoit, Jennifer V.

    2016-01-01

    Lattice degeneration of the retina is not infrequently encountered on a dilated retinal examination and many of them do not need any intervention. We report a case of atypical lattice degeneration variant with peripheral retinal detachment. An asymptomatic 35-year-old lady with minimal refractive error was found to have extensive lattice degeneration, peripheral retinal detachment and fibrotic changes peripherally with elevation of retinal vessels on dilated retinal examination. There were al...

  15. Towards new treatment strategies for intervertebral disc degeneration : Pathophysiology, histological and biochemical changes in IVD degeneration

    NARCIS (Netherlands)

    Rutges, J.P.H.J.

    2014-01-01

    Approximately 70% to 80% of all people worldwide will experience low back at any moment in their life. Intervertebral disc degeneration is an important cause of chronic low back pain. In most cases chronic low back pain can be treated conservatively with physiotherapy and analgesia. However, in some

  16. Family-Specific Degenerate Primer Design: A Tool to Design Consensus Degenerated Oligonucleotides

    Science.gov (United States)

    Goñi, Sandra Elizabeth; Lozano, Mario Enrique

    2013-01-01

    Designing degenerate PCR primers for templates of unknown nucleotide sequence may be a very difficult task. In this paper, we present a new method to design degenerate primers, implemented in family-specific degenerate primer design (FAS-DPD) computer software, for which the starting point is a multiple alignment of related amino acids or nucleotide sequences. To assess their efficiency, four different genome collections were used, covering a wide range of genomic lengths: Arenavirus (10 × 104 nucleotides), Baculovirus (0.9 × 105 to 1.8 × 105 bp), Lactobacillus sp. (1 × 106 to 2 × 106 bp), and Pseudomonas sp. (4 × 106 to 7 × 106 bp). In each case, FAS-DPD designed primers were tested computationally to measure specificity. Designed primers for Arenavirus and Baculovirus were tested experimentally. The method presented here is useful for designing degenerate primers on collections of related protein sequences, allowing detection of new family members. PMID:23533783

  17. Callosal degeneration topographically correlated with cognitive function in amnestic mild cognitive impairment and Alzheimer's disease dementia.

    Science.gov (United States)

    Wang, Pei-Ning; Chou, Kun-Hsien; Chang, Ni-Jung; Lin, Ker-Neng; Chen, Wei-Ta; Lan, Gong-Yau; Lin, Ching-Po; Lirng, Jiing-Feng

    2014-04-01

    Degeneration of the corpus callosum (CC) is evident in the pathogenesis of Alzheimer's disease (AD). However, the correlation of microstructural damage in the CC on the cognitive performance of patients with amnestic mild cognitive impairment (aMCI) and AD dementia is undetermined. We enrolled 26 normal controls, 24 patients with AD dementia, and 40 single-domain aMCI patients with at least grade 1 hippocampal atrophy and isolated memory impairment. Diffusion tensor imaging (DTI) with fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (DA), and radial diffusivity (DR) were measured. The entire CC was parcellated based on fiber trajectories to specific cortical Brodmann areas using a probabilistic tractography method. The relationship between the DTI measures in the subregions of the CC and cognitive performance was examined. Although the callosal degeneration in the patients with aMCI was less extended than in the patients with AD dementia, degeneration was already exhibited in several subregions of the CC at the aMCI stage. Scores of various neuropsychological tests were correlated to the severity of microstructural changes in the subregional CC connecting to functionally corresponding cortical regions. Our results confirm that CC degeneration is noticeable as early as the aMCI stage of AD and the disconnection of the CC subregional fibers to the corresponding Brodmann areas has an apparent impact on the related cognitive performance. Copyright © 2013 Wiley Periodicals, Inc.

  18. The prognosis of retinal detachment due to lattice degeneration.

    Science.gov (United States)

    Benson, W E; Morse, P H

    1978-09-01

    In a series of 553 consecutive retinal detachments, 29% (120) were due to lattice degeneration. Forty-five percent of these were due to atrophic holes in the lattice degeneration and 55% were due to tears caused by traction posterior to or at the end of a patch of lattice. In phakic patients, retinal detachments due to atrophic holes were most common in young myopes. Detachments due to traction tears were seen in older, less myopic patients. The incidence of massive periretinal proliferation was less (5%) in detachments due to lattice degeneration than in detachments not due to lattice degeneration (6.5%).

  19. Many-Body Green Function of Degenerate Systems

    International Nuclear Information System (INIS)

    Brouder, Christian; Panati, Gianluca; Stoltz, Gabriel

    2009-01-01

    A rigorous nonperturbative adiabatic approximation of the evolution operator in the many-body physics of degenerate systems is derived. This approximation is used to solve the long-standing problem of the choice of the initial states of H 0 leading to eigenstates of H 0 +V for degenerate systems. These initial states are eigenstates of P 0 VP 0 , where P 0 is the projection onto a degenerate eigenspace of H 0 . This result is used to give the proper definition of the Green function, the statistical Green function and the nonequilibrium Green function of degenerate systems. The convergence of these Green functions is established.

  20. Urinary incontinence and its functional anatomy in frontotemporal lobar degenerations

    Energy Technology Data Exchange (ETDEWEB)

    Perneczky, Robert [Technical University Munich Medical School, Department of Psychiatry and Psychotherapy, Munich (Germany); Technische Universitaet Muenchen, Klinik und Poliklinik fuer Psychiatrie und Psychotherapie, Muenchen (Germany); Diehl-Schmid, Janine; Foerstl, Hans; Kurz, Alexander [Technical University Munich Medical School, Department of Psychiatry and Psychotherapy, Munich (Germany); Drzezga, Alexander [Technical University Munich Medical School, Department of Nuclear Medicine, Munich (Germany); May, Florian [Technical University Munich Medical School, Department of Urology, Munich (Germany)

    2008-03-15

    The frontal lobes play a crucial role in micturition control. However, no reports exist on the functional role of distinct frontal brain regions in urinary incontinence (UIC) in patients with a neurodegenerative damage of the frontal lobe. The aim of the present study was therefore to explore if functional brain lesions were associated with UIC in patients suffering from frontotemporal lobar degenerations (FTLD). Forty-four patients, including eight incontinent subjects, underwent cranial positron emission tomography scanning with {sup 18}F-fluoro-2-deoxy-glucose ({sup 18}F-FDG PET) to assess the relative metabolic rate of glucose (rCMRglc). Group comparisons of rCMRglc were conducted in SPM2 to identify brain regions where the group of incontinent patients (FTLD+UIC) had significant alterations compared with the group without UIC (FTLD-UIC). At the stringent statistical threshold of p < 0.05, corrected for multiple comparisons according to the family-wise error rate, the statistical analysis revealed two significant right-hemispheric hypometabolic clusters located in the premotor/anterior cingulate cortex and the putamen/claustrum/insula. No hypermetabolic regions were found. The present study is the first to provide evidence for brain functional alterations involved in the occurrence of UIC in FTLD. These results provide an important piece of evidence to the understanding of a particularly distressing autonomic nervous system symptom of dementia. (orig.)

  1. Action potentials in retinal ganglion cells are initiated at the site of maximal curvature of the extracellular potential.

    Science.gov (United States)

    Eickenscheidt, Max; Zeck, Günther

    2014-06-01

    The initiation of an action potential by extracellular stimulation occurs after local depolarization of the neuronal membrane above threshold. Although the technique shows remarkable clinical success, the site of action and the relevant stimulation parameters are not completely understood. Here we identify the site of action potential initiation in rabbit retinal ganglion cells (RGCs) interfaced to an array of extracellular capacitive stimulation electrodes. We determine which feature of the extracellular potential governs action potential initiation by simultaneous stimulation and recording RGCs interfaced in epiretinal configuration. Stimulation electrodes were combined to areas of different size and were presented at different positions with respect to the RGC. Based on stimulation by electrodes beneath the RGC soma and simultaneous sub-millisecond latency measurement we infer axonal initiation at the site of maximal curvature of the extracellular potential. Stimulation by electrodes at different positions along the axon reveals a nearly constant threshold current density except for a narrow region close to the cell soma. These findings are explained by the concept of the activating function modified to consider a region of lower excitability close to the cell soma. We present a framework how to estimate the site of action potential initiation and the stimulus required to cross threshold in neurons tightly interfaced to capacitive stimulation electrodes. Our results underscore the necessity of rigorous electrical characterization of the stimulation electrodes and of the interfaced neural tissue.

  2. Action potentials in retinal ganglion cells are initiated at the site of maximal curvature of the extracellular potential

    Science.gov (United States)

    Eickenscheidt, Max; Zeck, Günther

    2014-06-01

    Objective. The initiation of an action potential by extracellular stimulation occurs after local depolarization of the neuronal membrane above threshold. Although the technique shows remarkable clinical success, the site of action and the relevant stimulation parameters are not completely understood. Approach. Here we identify the site of action potential initiation in rabbit retinal ganglion cells (RGCs) interfaced to an array of extracellular capacitive stimulation electrodes. We determine which feature of the extracellular potential governs action potential initiation by simultaneous stimulation and recording RGCs interfaced in epiretinal configuration. Stimulation electrodes were combined to areas of different size and were presented at different positions with respect to the RGC. Main results. Based on stimulation by electrodes beneath the RGC soma and simultaneous sub-millisecond latency measurement we infer axonal initiation at the site of maximal curvature of the extracellular potential. Stimulation by electrodes at different positions along the axon reveals a nearly constant threshold current density except for a narrow region close to the cell soma. These findings are explained by the concept of the activating function modified to consider a region of lower excitability close to the cell soma. Significance. We present a framework how to estimate the site of action potential initiation and the stimulus required to cross threshold in neurons tightly interfaced to capacitive stimulation electrodes. Our results underscore the necessity of rigorous electrical characterization of the stimulation electrodes and of the interfaced neural tissue.

  3. Assessment of Tibetan grassland degeneration via landscape analysis

    Science.gov (United States)

    Sun, Jian; Hou, Ge; Ma, Baibing; Zang, Wenqian

    2017-04-01

    Desertification as one of the most severity social-economic-environmental issues has been extensive researched, and the assessments of desertification can be implemented accurately and efficiently based on the landscape indicators of vegetation coverage. Consequently, we explored the relationships of the degeneration index of the grassland with climate factors (temperature and precipitation), and human disturbance factors (livestock quantity and animal husbandry output value) via a landscape assessment approach across Tibet. The results showed that the vegetation coverage presented an increase tendency in the central region of Tibet, but the adverse phenomenon was observed in the northwest region. Meanwhile, the correlation of vegetation coverage with precipitation presented as positive effect in most region of Tibet except some regions of the alpine steppe, and the positive correlation of vegetation coverage with temperature also was observed in the less northwest region of Tibet. In addition, we found that the livestock quantity play a key roles in regulating vegetation coverage of the central region. Furthermore, the landscape indexes [number of patches (NP), patch density (PD), contagion index (CONTAG), landscape shape index (LSI), aggregation index (AI)] of grasslands were analyzed, the results exposed that vegetation coverage (1%-20%) has the positive influences on CONTAG and AI, but negative affects LSI, PD and NP. Morreover, there are opposite correlations among vegetation coverage and landscape indexes when vegetation coverage is 21%-40%. We concluded that overgrazing is the main reason of grassland degradation in Tibet, especially the number of livestock aggravates the landscape fragmentation. The results highlighted the alpine grassland management in future.

  4. MR imaging findings of hypertrophic olivary degeneration

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Do Joong; Jeon, Pyung; Kim, Dong Ik [Yonsei Univ. College of Medicine, Seoul (Korea, Republic of)

    1997-06-01

    To describe the magnetic resonance (MR) imaging findings of hypertrophic olivary degeneration (HOD) MR images of seven patients with HOD were retrospectively reviewed. Two were women and five were men, and they were aged between 48 and 65 (mean 58) years. Imaging examinations were performed with a 1.5-T unit, and the findings were used to evaluate the size and signal intensity of olivary lesions. The time interval from hemorrhagic ictus to MR imaging was between two and 30 months. Follow-up examinations were performed in two patients. All four patients with hemorrhages involving the central tegmental tract in the pons or midbrain showed ipsilateral HOD. Among these four, bilateral HOD was seen in one patient with hemorrhage involving the bilateral central tegmental tract, and in another with tegmental hemorrhage extending to the ipsilateral superior cerebellar peduncle. One patient with cerebellar hemorrhage involving the dentate nucleus had contralateral HOD. Two patients with multiple hemorrhages involving both the pons and cerebellum showed bilateral HOD. Axial MR images showed mild enlargement of the involved olivary mucleus, with high signal intensity on both proton density and T2 weighted images. There was no apparent enhancement on postcontrast T1-weighted images. MR imaging can clearly distinguish secondary olivary degeneration from underlying pathology involving the central tegmental tract in the pons or midbrain and cerebellum. These olivary abnormalities should not, however, be mistaken for primary medullary lesions.

  5. Getting superstring amplitudes by degenerating Riemann surfaces

    International Nuclear Information System (INIS)

    Matone, Marco; Volpato, Roberto

    2010-01-01

    We explicitly show how the chiral superstring amplitudes can be obtained through factorisation of the higher genus chiral measure induced by suitable degenerations of Riemann surfaces. This powerful tool also allows to derive, at any genera, consistency relations involving the amplitudes and the measure. A key point concerns the choice of the local coordinate at the node on degenerate Riemann surfaces that greatly simplifies the computations. As a first application, starting from recent ansaetze for the chiral measure up to genus five, we compute the chiral two-point function for massless Neveu-Schwarz states at genus two, three and four. For genus higher than three, these computations include some new corrections to the conjectural formulae appeared so far in the literature. After GSO projection, the two-point function vanishes at genus two and three, as expected from space-time supersymmetry arguments, but not at genus four. This suggests that the ansatz for the superstring measure should be corrected for genus higher than four.

  6. MR imaging findings of hypertrophic olivary degeneration

    International Nuclear Information System (INIS)

    Kim, Do Joong; Jeon, Pyung; Kim, Dong Ik

    1997-01-01

    To describe the magnetic resonance (MR) imaging findings of hypertrophic olivary degeneration (HOD) MR images of seven patients with HOD were retrospectively reviewed. Two were women and five were men, and they were aged between 48 and 65 (mean 58) years. Imaging examinations were performed with a 1.5-T unit, and the findings were used to evaluate the size and signal intensity of olivary lesions. The time interval from hemorrhagic ictus to MR imaging was between two and 30 months. Follow-up examinations were performed in two patients. All four patients with hemorrhages involving the central tegmental tract in the pons or midbrain showed ipsilateral HOD. Among these four, bilateral HOD was seen in one patient with hemorrhage involving the bilateral central tegmental tract, and in another with tegmental hemorrhage extending to the ipsilateral superior cerebellar peduncle. One patient with cerebellar hemorrhage involving the dentate nucleus had contralateral HOD. Two patients with multiple hemorrhages involving both the pons and cerebellum showed bilateral HOD. Axial MR images showed mild enlargement of the involved olivary mucleus, with high signal intensity on both proton density and T2 weighted images. There was no apparent enhancement on postcontrast T1-weighted images. MR imaging can clearly distinguish secondary olivary degeneration from underlying pathology involving the central tegmental tract in the pons or midbrain and cerebellum. These olivary abnormalities should not, however, be mistaken for primary medullary lesions

  7. Vitreous in lattice degeneration of retina.

    Science.gov (United States)

    Foos, R Y; Simons, K B

    1984-05-01

    A localized pocket of missing vitreous invariably overlies lattice degeneration of the retina. Subjects with lattice also have a higher rate of rhegmatogenous retinal detachment, which is usually a complication of retinal tears. The latter are in turn a result of alterations in the central vitreous--that is, synchysis senilis leading to posterior vitreous detachment. In order to determine if there is either an association or a deleterious interaction between the local and central lesions of the vitreous in eyes with lattice, a comparison was made in autopsy eyes with and without lattice the degree of synchysis and rate of vitreous detachment. Results show no association between the local and central vitreous lesions, indicating that a higher rate of vitreous detachment is not the basis for the higher rate of retinal detachment in eyes with lattice. Also, there was no suggestion of deleterious interaction between the local and central vitreous lesions, either through vitreodonesis as a basis for precocious vitreous detachment, or through a greater degree of synchysis as a basis for interconnection of local and central lacunae (which could extend the localized retinal detachment in eyes with holes in lattice degeneration).

  8. Visual signs and symptoms of corticobasal degeneration.

    Science.gov (United States)

    Armstrong, Richard A

    2016-11-01

    Corticobasal degeneration is a rare, progressive neurodegenerative disease and a member of the 'parkinsonian' group of disorders, which also includes Parkinson's disease, progressive supranuclear palsy, dementia with Lewy bodies and multiple system atrophy. The most common initial symptom is limb clumsiness, usually affecting one side of the body, with or without accompanying rigidity or tremor. Subsequently, the disease affects gait and there is a slow progression to influence ipsilateral arms and legs. Apraxia and dementia are the most common cortical signs. Corticobasal degeneration can be difficult to distinguish from other parkinsonian syndromes but if ocular signs and symptoms are present, they may aid clinical diagnosis. Typical ocular features include increased latency of saccadic eye movements ipsilateral to the side exhibiting apraxia, impaired smooth pursuit movements and visuo-spatial dysfunction, especially involving spatial rather than object-based tasks. Less typical features include reduction in saccadic velocity, vertical gaze palsy, visual hallucinations, sleep disturbance and an impaired electroretinogram. Aspects of primary vision such as visual acuity and colour vision are usually unaffected. Management of the condition to deal with problems of walking, movement, daily tasks and speech problems is an important aspect of the disease. © 2016 Optometry Australia.

  9. Progranulin in frontotemporal lobar degeneration and neuroinflammation

    Directory of Open Access Journals (Sweden)

    Hutton Michael L

    2007-02-01

    Full Text Available Abstract Progranulin (PGRN is a pleiotropic protein that has gained the attention of the neuroscience community with recent discoveries of mutations in the gene for PGRN that cause frontotemporal lobar degeneration (FTLD. Pathogenic mutations in PGRN result in null alleles, and the disease is likely the result of haploinsufficiency. Little is known about the normal function of PGRN in the central nervous system apart from a role in brain development. It is expressed by microglia and neurons. In the periphery, PGRN is involved in wound repair and inflammation. High PGRN expression has been associated with more aggressive growth of various tumors. The properties of full length PGRN are distinct from those of proteolytically derived peptides, referred to as granulins (GRNs. While PGRN has trophic properties, GRNs are more akin to inflammatory mediators such as cytokines. Loss of the neurotrophic properties of PGRN may play a role in selective neuronal degeneration in FTLD, but neuroinflammation may also be important. Gene expression studies suggest that PGRN is up-regulated in a variety of neuroinflammatory conditions, and increased PGRN expression by microglia may play a pivotal role in the response to brain injury, neuroinflammation and neurodegeneration.

  10. Resección guiada por ecografía de gangliones dorsales de muñeca. [Ultrasound-Guided resection of dorsal wrist ganglion

    Directory of Open Access Journals (Sweden)

    Damián G. Bustos

    2015-01-01

    Full Text Available In­tro­duc­ción: el objetivo de este trabajo fue evaluar prospectivamente los resultados del drenaje de gangliones dorsales de muñeca y la ruptura de su pedículo guiada por ecografía, y determinar su tasa de recidiva, las complicaciones y los resultados subjetivos. Materiales ­y ­Métodos: se evaluaron prospectivamente 32 pacientes con gangliones dorsales sintomáticos de muñeca tratados mediante punción guiada por ecografía, aspiración del contenido y ruptura del pedículo con un trocar, entre enero de 2010 y junio de 2011. La edad de los pacientes promedió 31 años. Todos realizaban tareas administrativas, y retornaron a sus tareas habituales al día siguiente del procedimiento. El puntaje DASH previo al procedimiento fue, en promedio, de 2,90. El dolor previo al procedimiento promedió 7,75 puntos. Se separó a los pacientes en dos grupos, gangliones primarios (grupo 1: 19 pacientes y gangliones recurrentes con cirugía previa (grupo 2: 13 pacientes. Resultados: once pacientes tuvieron recidivas (34,3% al año de seguimiento: 5 del grupo 1 (26,31% y 6 del grupo 2 (46,1%. El puntaje DASH a los 6 meses promedió 1,91 (rango 1,02-3,98. El dolor a los 6 meses promedió 1,53 puntos (rango 0-4. Ningún paciente presentó complicaciones neurológicas o tendinosas, infección o hematomas (seguimiento promedio 6 meses. Conclusión:­ la técnica bajo control ecográfico es mínimamente invasiva con una tasa de recurrencia aceptable (26% en pacientes sin antecedente quirúrgico, considerando que plantea menores riesgos que los procedimientos quirúrgicos al igual que un menor costo y bajo costo laboral.

  11. Specific and somatotopic functional magnetic resonance imaging activation in the trigeminal ganglion by brush and noxious heat.

    Science.gov (United States)

    Borsook, David; DaSilva, Alexandre F M; Ploghaus, Alex; Becerra, Lino

    2003-08-27

    We used functional magnetic resonance imaging (fMRI) to assess activation in the trigeminal ganglion during innocuous mechanical (brush) and noxious thermal (46 degrees C) stimulation of the face within the receptive fields of each of the three divisions of the trigeminal nerve in healthy volunteers. For both stimulus types, we observed signal changes only in the ipsilateral ganglion, and activation occurred somatotopically, as predicted by the known anatomical segregation of the neurons comprising the ophthalmic (V1), maxillary (V2), and mandibular (V3) divisions of the nerve. Signal decreased after brush stimuli and increased after the application of noxious heat. The abilities to detect somatotopic activation within the ganglion and to segregate non-noxious mechanical from noxious thermal stimuli suggest that fMRI will be valuable for measuring changes in the trigeminal ganglion in human models of neuropathic pain and in the clinical condition itself and may also be useful in the evaluation of pain therapies.

  12. Enlarged superior cervical sympathetic ganglion mimicking a metastatic lymph node in the retropharyngeal space: A case report

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jae Min; Kim, Jin Na; Kim, Se Hoon; Choi, Eun Chang [Severance Hospital, Yonsei University College of Medicine, Seoul (Korea, Republic of)

    2017-04-15

    The superior cervical sympathetic ganglion, the largest and most cranial of the three cervical sympathetic ganglia, transfers sympathetic signals to specific targets on the head and neck. This ganglion is located just lateral to the retropharyngeal space along the medial margin of the carotid sheath. Located thus, an enlarged superior cervical sympathetic ganglion can mimic a metastatic lymph node in the retropharyngeal space of the suprahyoid neck in head and neck cancer patients. However, this is often disregarded by radiologists due to lack of interest in its anatomic location. We present a case of an enlarged superior cervical sympathetic ganglion mimicking a retropharyngeal metastatic lymph node in a 42-year-old man with oral tongue cancer.

  13. Localization of CGRP, CGRP receptor, PACAP and glutamate in trigeminal ganglion. Relation to the blood-brain barrier

    DEFF Research Database (Denmark)

    Eftekhari, Sajedeh; Salvatore, Christopher A; Johansson, Sara

    2015-01-01

    Calcitonin gene-related peptide (CGRP) receptor antagonists have demonstrated anti-migraine efficacy. One remaining question is where do these blockers act? We hypothesized that the trigeminal ganglion could be one possible site. We examined the binding sites of a CGRP receptor antagonist (MK-3207......) and related this to the expression of CGRP and its receptor in rhesus trigeminal ganglion. Pituitary adenylate cyclase-activating polypeptide (PACAP) and glutamate were examined and related to the CGRP system. Furthermore, we examined if the trigeminal ganglion is protected by the blood-brain barrier (BBB......). Autoradiography was performed with [(3)H]MK-3207 to demonstrate receptor binding sites in rhesus trigeminal ganglion (TG). Immunofluorescence was used to correlate binding and the presence of CGRP and its receptor components, calcitonin receptor-like receptor (CLR) and receptor activity-modifying protein 1 (RAMP1...

  14. Large infrapatellar ganglionic cyst of the knee fat pad: a case report and review of the literature

    Directory of Open Access Journals (Sweden)

    Ilias Apostolos

    2011-08-01

    Full Text Available Abstract Introduction Large ganglionic cystic formations arising from the infrapatellar fat pad are quite uncommon and only a few are mentioned in the literature. An open excision in these cases is mandatory. Case presentation We report the case of a large infrapatellar fat pad ganglion in a 37-year-old Greek man with chronic knee discomfort. The ganglionic cyst originated from the infrapatellar fat pad and had no intrasynovial extension. The final diagnosis was determined with magnetic resonance imaging of the knee, and the lesion was treated with surgery. Conclusions These lesions are asymptomatic in most cases but often are misdiagnosed as meniscal or ligamentous lesions of the knee joint. Nowadays, the therapeutic trend for such lesions is arthroscopic excision, but when there is a large ganglion, as in this case report, the treatment should be an open and thorough resection. This report is intended mostly but not exclusively for clinical physicians and radiologists.

  15. Delayed neurogenesis leads to altered specification of ventrotemporal retinal ganglion cells in albino mice

    Science.gov (United States)

    2014-01-01

    Background Proper binocular vision depends on the routing at the optic chiasm of the correct proportion of retinal ganglion cell (RGC) axons that project to the same (ipsilateral) and opposite (contralateral) side of the brain. The ipsilateral RGC projection is reduced in mammals with albinism, a congenital disorder characterized by deficient pigmentation in the skin, hair, and eyes. Compared to the pigmented embryonic mouse retina, the albino embryonic mouse retina has fewer RGCs that express the zinc-finger transcription factor, Zic2, which is transiently expressed by RGCs fated to project ipsilaterally. Here, using Zic2 as a marker of ipsilateral RGCs, Islet2 as a marker of contralateral RGCs, and birthdating, we investigate spatiotemporal dynamics of RGC production as they relate to the phenotype of diminished ipsilateral RGC number in the albino retina. Results At embryonic day (E)15.5, fewer Zic2-positive (Zic2+) RGCs are found in the albino ventrotemporal (VT) retina compared with the pigmented VT retina, as we previously reported. However, the reduction in Zic2+ RGCs in the albino is not accompanied by a compensatory increase in Zic2-negative (Zic2−) RGCs, resulting in fewer RGCs in the VT retina at this time point. At E17.5, however, the number of RGCs in the VT region is similar in pigmented and albino retinae, implicating a shift in the timing of RGC production in the albino. Short-term birthdating assays reveal a delay in RGC production in the albino VT retina between E13 and E15. Specifically, fewer Zic2+ RGCs are born at E13 and more Zic2− RGCs are born at E15. Consistent with an increase in the production of Zic2− RGCs born at later ages, more RGCs at E17.5 express the contralateral marker, Islet2, in the albino VT retina compared with the pigmented retina. Conclusions A delay in neurogenesis in the albino retina is linked to the alteration of RGC subtype specification and consequently leads to the reduced ipsilateral projection that

  16. Anterograde glycoprotein-dependent transport of newly generated rabies virus in dorsal root ganglion neurons.

    Science.gov (United States)

    Bauer, Anja; Nolden, Tobias; Schröter, Josephine; Römer-Oberdörfer, Angela; Gluska, Shani; Perlson, Eran; Finke, Stefan

    2014-12-01

    Rabies virus (RABV) spread is widely accepted to occur only by retrograde axonal transport. However, examples of anterograde RABV spread in peripheral neurons such as dorsal root ganglion (DRG) neurons indicated a possible bidirectional transport by an uncharacterized mechanism. Here, we analyzed the axonal transport of fluorescence-labeled RABV in DRG neurons by live-cell microscopy. Both entry-related retrograde transport of RABV after infection at axon endings and postreplicative transport of newly formed virus were visualized in compartmentalized DRG neuron cultures. Whereas entry-related transport at 1.5 μm/s occurred only retrogradely, after 2 days of infection, multiple particles were observed in axons moving in both the anterograde and retrograde directions. The dynamics of postreplicative retrograde transport (1.6 μm/s) were similar to those of entry-related retrograde transport. In contrast, anterograde particle transport at 3.4 μm/s was faster, indicating active particle transport. Interestingly, RABV missing the glycoproteins did not move anterogradely within the axon. Thus, anterograde RABV particle transport depended on the RABV glycoprotein. Moreover, colocalization of green fluorescent protein (GFP)-labeled ribonucleoproteins (RNPs) and glycoprotein in distal axonal regions as well as cotransport of labeled RNPs with membrane-anchored mCherry reporter confirmed that either complete enveloped virus particles or vesicle associated RNPs were transported. Our data show that anterograde RABV movement in peripheral DRG neurons occurs by active motor protein-dependent transport. We propose two models for postreplicative long-distance transport in peripheral neurons: either transport of complete virus particles or cotransport of RNPs and G-containing vesicles through axons to release virus at distal sites of infected DRG neurons. Rabies virus retrograde axonal transport by dynein motors supports virus spread over long distances and lethal infection of

  17. Axonal transmission in the retina introduces a small dispersion of relative timing in the ganglion cell population response.

    Directory of Open Access Journals (Sweden)

    Günther Zeck

    Full Text Available BACKGROUND: Visual stimuli elicit action potentials in tens of different retinal ganglion cells. Each ganglion cell type responds with a different latency to a given stimulus, thus transforming the high-dimensional input into a temporal neural code. The timing of the first spikes between different retinal projection neurons cells may further change along axonal transmission. The purpose of this study is to investigate if intraretinal conduction velocity leads to a synchronization or dispersion of the population signal leaving the eye. METHODOLOGY/PRINCIPAL FINDINGS: We 'imaged' the initiation and transmission of light-evoked action potentials along individual axons in the rabbit retina at micron-scale resolution using a high-density multi-transistor array. We measured unimodal conduction velocity distributions (1.3±0.3 m/sec, mean ± SD for axonal populations at all retinal eccentricities with the exception of the central part that contains myelinated axons. The velocity variance within each piece of retina is caused by ganglion cell types that show narrower and slightly different average velocity tuning. Ganglion cells of the same type respond with similar latency to spatially homogenous stimuli and conduct with similar velocity. For ganglion cells of different type intraretinal conduction velocity and response latency to flashed stimuli are negatively correlated, indicating that differences in first spike timing increase (up to 10 msec. Similarly, the analysis of pair-wise correlated activity in response to white-noise stimuli reveals that conduction velocity and response latency are negatively correlated. CONCLUSION/SIGNIFICANCE: Intraretinal conduction does not change the relative spike timing between ganglion cells of the same type but increases spike timing differences among ganglion cells of different type. The fastest retinal ganglion cells therefore act as indicators of new stimuli for postsynaptic neurons. The intraretinal dispersion

  18. Automated degenerate PCR primer design for high-throughput sequencing improves efficiency of viral sequencing

    Directory of Open Access Journals (Sweden)

    Li Kelvin

    2012-11-01

    Full Text Available Abstract Background In a high-throughput environment, to PCR amplify and sequence a large set of viral isolates from populations that are potentially heterogeneous and continuously evolving, the use of degenerate PCR primers is an important strategy. Degenerate primers allow for the PCR amplification of a wider range of viral isolates with only one set of pre-mixed primers, thus increasing amplification success rates and minimizing the necessity for genome finishing activities. To successfully select a large set of degenerate PCR primers necessary to tile across an entire viral genome and maximize their success, this process is best performed computationally. Results We have developed a fully automated degenerate PCR primer design system that plays a key role in the J. Craig Venter Institute’s (JCVI high-throughput viral sequencing pipeline. A consensus viral genome, or a set of consensus segment sequences in the case of a segmented virus, is specified using IUPAC ambiguity codes in the consensus template sequence to represent the allelic diversity of the target population. PCR primer pairs are then selected computationally to produce a minimal amplicon set capable of tiling across the full length of the specified target region. As part of the tiling process, primer pairs are computationally screened to meet the criteria for successful PCR with one of two described amplification protocols. The actual sequencing success rates for designed primers for measles virus, mumps virus, human parainfluenza virus 1 and 3, human respiratory syncytial virus A and B and human metapneumovirus are described, where >90% of designed primer pairs were able to consistently successfully amplify >75% of the isolates. Conclusions Augmenting our previously developed and published JCVI Primer Design Pipeline, we achieved similarly high sequencing success rates with only minor software modifications. The recommended methodology for the construction of the consensus

  19. Dendritic maturation in cat retinal ganglion cells: a Lucifer yellow study.

    Science.gov (United States)

    Dann, J F; Buhl, E H; Peichl, L

    1987-09-11

    The dendritic morphology of developing cat alpha- and beta-retinal ganglion cells was investigated by intracellular injection of Lucifer yellow. In both cell classes the basic pattern of adult morphology was present at birth. However, the presence of transient small spiny protrusions along the dendrites was characteristic of early postnatal cells. Many alpha-cells were further distinguished by a small degree of dendritic bi-stratification which disappeared within the first 5 postnatal days. Therefore during the period before the eyes opened (P7-P10) there was a considerable degree of modification and maturation in dendritic morphology in both classes of retinal ganglion cells. alpha- and beta-cells exhibited differing temporal patterns of dendritic growth, which argues against a 'passive-stretching' hypothesis that explains dendritic field enlargement solely as an effect of retinal areal growth.

  20. A Learning Model for L/M Specificity in Ganglion Cells

    Science.gov (United States)

    Ahumada, Albert J.

    2016-01-01

    An unsupervised learning model for developing LM specific wiring at the ganglion cell level would support the research indicating LM specific wiring at the ganglion cell level (Reid and Shapley, 2002). Removing the contributions to the surround from cells of the same cone type improves the signal-to-noise ratio of the chromatic signals. The unsupervised learning model used is Hebbian associative learning, which strengthens the surround input connections according to the correlation of the output with the input. Since the surround units of the same cone type as the center are redundant with the center, their weights end up disappearing. This process can be thought of as a general mechanism for eliminating unnecessary cells in the nervous system.

  1. Diversity of retinal ganglion cells identified by transient GFP transfection in organotypic tissue culture of adult marmoset monkey retina.

    Directory of Open Access Journals (Sweden)

    Satoru Moritoh

    Full Text Available The mammalian retina has more diversity of neurons than scientists had once believed in order to establish complicated vision processing. In the monkey retina, morphological diversity of retinal ganglion cells (RGCs besides dominant midget and parasol cells has been suggested. However, characteristic subtypes of RGCs in other species such as bistratified direction-selective ganglion cells (DSGC have not yet been identified. Increasing interest has been shown in the common marmoset (Callithrix jacchus monkey as a "super-model" of neuroscientific research. Here, we established organotypic tissue culture of the adult marmoset monkey retina with particle-mediated gene transfer of GFP to survey the morphological diversity of RGCs. We successfully incubated adult marmoset monkey retinas for 2 to 4 days ex vivo for transient expression of GFP. We morphologically examined 121 RGCs out of more than 3240 GFP-transfected cells in 5 retinas. Among them, we identified monostratified or broadly stratified ganglion cells (midget, parasol, sparse, recursive, thorny, and broad thorny ganglion cells, and bistratified ganglion cells (recursive, large, and small bistratified ganglion cells [blue-ON/yellow-OFF-like]. By this survey, we also found a candidate for bistratified DSGC whose dendrites were well cofasciculated with ChAT-positive starburst dendrites, costratified with ON and OFF ChAT bands, and had honeycomb-shaped dendritic arbors morphologically similar to those in rabbits. Our genetic engineering method provides a new approach to future investigation for morphological and functional diversity of RGCs in the monkey retina.

  2. Delivery systems for the treatment of degenerated intervertebral discs

    NARCIS (Netherlands)

    Blanquer, S. B. G.; Grijpma, D. W.; Poot, A. A.

    The intervertebral disc (ND) is the most avascular and acellular tissue in the body and therefore prone to degeneration. During IVD degeneration, the balance between anabolic and catabolic processes in the disc is deregulated, amongst others leading to alteration of extracellular matrix production,

  3. Prevalence of age-related macular degeneration in elderly Caucasians

    DEFF Research Database (Denmark)

    Erke, Maja G; Bertelsen, Geir; Peto, Tunde

    2012-01-01

    To describe the sex- and age-specific prevalence of drusen, geographic atrophy, and neovascular age-related macular degeneration (AMD).......To describe the sex- and age-specific prevalence of drusen, geographic atrophy, and neovascular age-related macular degeneration (AMD)....

  4. Lattice degeneration of the retina and retinal detachment.

    Science.gov (United States)

    Semes, L P

    1992-01-01

    Lattice retinal degeneration is considered the most significant peripheral retinal disorder potentially predisposing to retinal breaks and retinal detachment. Lattice degeneration affects the vitreous and inner retinal layers with secondary changes as deep as the retinal pigment epithelium and perhaps the choriocapillaris. Variations in clinical appearance are the rule; geographically, lattice lesions favor the vertical meridians between the equator and the ora serrata. Lattice degeneration begins early in life and has been reported in sequential generations of the same family. Along with its customary bilateral occurrence, lattice shares other characteristics of a dystrophy. The association between the vitreous and retina in lattice lesions may be responsible for the majority of lattice-induced retinal detachments. The tumultuous event of posterior vitreous separation in the presence of abnormally strong vitreoretinal adherence is the trigger for a retinal tear that, in turn, may lead to retinal detachment. Although retinal holes in young patients with lattice degeneration may play a role in the evolution of retinal detachment, the clinical course of lattice degeneration seems to be one of dormancy rather than of progressive change. This discussion outlines the pathophysiology of lattice retinal degeneration and the relationship of pathophysiology to clinical presentation. The epidemiology of lattice degeneration is summarized, as are the possible precursors to retinal detachment. A clinical characterization of the natural history of lattice degeneration is offered, and interventions for complications are described. To conclude, management strategies from a primary-care standpoint are reviewed.

  5. Viscosity solution of linear regulator quadratic for degenerate diffusions

    Directory of Open Access Journals (Sweden)

    2006-01-01

    Full Text Available The paper studied a linear regulator quadratic control problem for degenerate Hamilton-Jacobi-Bellman (HJB equation. We showed the existence of viscosity properties and established a unique viscosity solution of the degenerate HJB equation associated with this problem by the technique of viscosity solutions.

  6. Uniform signal redundancy of parasol and midget ganglion cells in primate retina

    OpenAIRE

    Gauthier, Jeffrey L.; Field, Greg D.; Sher, Alexander; Shlens, Jonathon; Greschner, Martin; Litke, Alan M.; Chichilnisky, E.J.

    2009-01-01

    The collective representation of visual space in high resolution visual pathways was explored by simultaneously measuring the receptive fields of hundreds of ON and OFF midget and parasol ganglion cells in isolated primate retina. As expected, the receptive fields of all four cell types formed regular mosaics uniformly tiling the visual scene. Surprisingly, comparison of all four mosaics revealed that the overlap of neighboring receptive fields was nearly identical, for both the excitatory ce...

  7. Seasonally Changing Cryptochrome 1b Expression in the Retinal Ganglion Cells of a Migrating Passerine Bird.

    Directory of Open Access Journals (Sweden)

    Christine Nießner

    Full Text Available Cryptochromes, blue-light absorbing proteins involved in the circadian clock, have been proposed to be the receptor molecules of the avian magnetic compass. In birds, several cryptochromes occur: Cryptochrome 2, Cryptochrome 4 and two splice products of Cryptochrome 1, Cry1a and Cry1b. With an antibody not distinguishing between the two splice products, Cryptochrome 1 had been detected in the retinal ganglion cells of garden warblers during migration. A recent study located Cry1a in the outer segments of UV/V-cones in the retina of domestic chickens and European robins, another migratory species. Here we report the presence of cryptochrome 1b (eCry1b in retinal ganglion cells and displaced ganglion cells of European Robins, Erithacus rubecula. Immuno-histochemistry at the light microscopic and electron microscopic level showed eCry1b in the cell plasma, free in the cytosol as well as bound to membranes. This is supported by immuno-blotting. However, this applies only to robins in the migratory state. After the end of the migratory phase, the amount of eCry1b was markedly reduced and hardly detectable. In robins, the amount of eCry1b in the retinal ganglion cells varies with season: it appears to be strongly expressed only during the migratory period when the birds show nocturnal migratory restlessness. Since the avian magnetic compass does not seem to be restricted to the migratory phase, this seasonal variation makes a role of eCry1b in magnetoreception rather unlikely. Rather, it could be involved in physiological processes controlling migratory restlessness and thus enabling birds to perform their nocturnal flights.

  8. [Sphenopalatine ganglion pulsed radiofrequency treatment in patients suffering from chronic face and head pain].

    Science.gov (United States)

    Akbas, Mert; Gunduz, Emel; Sanli, Suat; Yegin, Arif

    2016-01-01

    There are various facial pain syndromes including trigeminal neuralgia, trigeminal neuropathic pain and atypical facial pain syndromes. Effectiveness of the pulsed radiofrequency in managing various pain syndromes has been clearly demonstrated. There are a limited number of studies on the pulsed radiofrequency treatment for sphenopalatine ganglion in patients suffering from face and head pain. The purpose of this study is to evaluate the satisfaction of pulsed radiofrequency treatment at our patients retrospectively. Infrazygomatic approach was used for the pulsed radiofrequency of the sphenopalatine ganglion under fluoroscopic guidance. After the tip of the needle reached the target point, 0.25-0.5ms pulse width was applied for sensory stimulation at frequencies from 50Hz to 1V. Paraesthesias were exposed at the roof of the nose at 0.5-0.7V. To rule out trigeminal contact that led to rhythmic mandibular contraction, motor stimulation at a frequency of 2Hz was applied. Then, four cycles of pulsed radiofrequency lesioning were performed for 120s at a temperature of 42°C. Pain relief could not be achieved in 23% of the patients (unacceptable), whereas pain was completely relieved in 35% of the patients (excellent) and mild to moderate pain relief could be achieved in 42% of the patients (good) through sphenopalatine ganglion-pulsed radiofrequency treatment. Pulsed radiofrequency of the sphenopalatine ganglion is effective in treating the patients suffering from intractable chronic facial and head pain as shown by our findings. There is a need for prospective, randomized, controlled trials in order to confirm the efficacy and safety of this new treatment modality in chronic head and face pain. Copyright © 2014 Sociedade Brasileira de Anestesiologia. Publicado por Elsevier Editora Ltda. All rights reserved.

  9. Sphenopalatine ganglion pulsed radiofrequency treatment in patients suffering from chronic face and head pain.

    Science.gov (United States)

    Akbas, Mert; Gunduz, Emel; Sanli, Suat; Yegin, Arif

    2016-01-01

    There are various facial pain syndromes including trigeminal neuralgia, trigeminal neuropathic pain and atypical facial pain syndromes. Effectiveness of the pulsed radiofrequency in managing various pain syndromes has been clearly demonstrated. There are a limited number of studies on the pulsed radiofrequency treatment for sphenopalatine ganglion in patients suffering from face and head pain. The purpose of this study is to evaluate the satisfaction of pulsed radiofrequency treatment at our patients retrospectively. Infrazygomatic approach was used for the pulsed radiofrequency of the sphenopalatine ganglion under fluoroscopic guidance. After the tip of the needle reached the target point, 0.25-0.5 ms pulse width was applied for sensory stimulation at frequencies from 50 Hz to 1 V. Paraesthesias were exposed at the roof of the nose at 0.5-0.7 V. To rule out trigeminal contact that led to rhythmic mandibular contraction, motor stimulation at a frequency of 2 Hz was applied. Then, four cycles of pulsed radiofrequency lesioning were performed for 120 s at a temperature of 42°C. Pain relief could not be achieved in 23% of the patients (unacceptable), whereas pain was completely relieved in 35% of the patients (excellent) and mild to moderate pain relief could be achieved in 42% of the patients (good) through sphenopalatine ganglion-pulsed radiofrequency treatment. Pulsed radiofrequency of the sphenopalatine ganglion is effective in treating the patients suffering from intractable chronic facial and head pain as shown by our findings. There is a need for prospective, randomized, controlled trials in order to confirm the efficacy and safety of this new treatment modality in chronic head and face pain. Copyright © 2014 Sociedade Brasileira de Anestesiologia. Published by Elsevier Editora Ltda. All rights reserved.

  10. [Alternative approach to autonomic instability of very severe tetanus: stellate ganglion block].

    Science.gov (United States)

    Altıparmak, Başak; Uysal, Ali İhsan; Yaşar, Eylem; Demirbilek, Semra

    Tetanus is an acute and deadly disease caused by Clostridium tetani. A 60-year-old male came to hospital after he injured his thumb with a knife. Ten days later, he returned to hospital with abdominal spasms. He was vaccinated against tetanus and referred to intensive care unit. As he had sudden difficulty in respiration, he was entubated. Midazolam, magnesium and esmolol infusion were started. Next day, muscle spasms progressed all over his body. Midazolam infusion was replaced with propofol and vecuronium. At the third day, morphine infusion was added. At the 16th day, dexmedetomidine infusion was started. At the 20 th day, ultrasound guided stellate ganglion block was performed to denervate sympathetic activity. The block was performed three times in a 10 days period. At the 30 th the patient recovered from very severe tetanus. The mainstay of tetanus treatment is adequate sedation. Neuroaxial blocks were proved to be effective for the control of sympathetic overactivity in recent years. Circulatory collapse remains to be the major cause of death. The mechanism is unclear but altered myocardial function is thought to be related to changeable catecholamine levels. The effect of stellate ganglion block on sympathetic and parasympathetic control of heart has been studied since the beginning of 1980s. Recently Scanlon et al. reported they treated a patient with medically refractory ventricular arrhythmias by ultrasound guided bilateral stellate ganglion block. In conclusion, stellate ganglion block can be an alternative method when the autonomic storm cannot be controlled with medical agents. Copyright © 2016 Sociedade Brasileira de Anestesiologia. Publicado por Elsevier Editora Ltda. All rights reserved.

  11. Retinal ganglion cell topography and spatial resolving power in the white rhinoceros (Ceratotherium simum).

    Science.gov (United States)

    Coimbra, João Paulo; Manger, Paul R

    2017-08-01

    This study sought to determine whether the retinal organization of the white rhinoceros (Ceratotherium simum), a large African herbivore with lips specialized for grazing in open savannahs, relates to its foraging ecology and habitat. Using stereology and retinal wholemounts, we estimated a total of 353,000 retinal ganglion cells. Their density distribution reveals an unusual topographic organization of a temporal (2,000 cells/mm 2 ) and a nasal (1,800 cells/mm 2 ) area embedded within a well-defined horizontal visual streak (800 cells/mm 2 ), which is remarkably similar to the retinal organization in the black rhinoceros. Alpha ganglion cells comprise 3.5% (12,300) of the total population of ganglion cells and show a similar distribution pattern with maximum densities also occurring in the temporal (44 cells/mm 2 ) and nasal (40 cells/mm 2 ) areas. We found higher proportions of alpha cells in the dorsal and ventral retinas. Given their role in the detection of brisk transient stimuli, these higher proportions may facilitate the detection of approaching objects from the front and behind while grazing with the head at 45 °. Using ganglion cell peak density and eye size (29 mm, axial length), we estimated upper limits of spatial resolving power of 7 cycles/deg (temporal area), 6.6 cycles/deg (nasal area), and 4.4 cycles/deg (horizontal streak). The resolution of the temporal area potentially assists with grazing, while the resolution of the streak may be used for panoramic surveillance of the horizon. The nasal area may assist with detection of approaching objects from behind, potentially representing an adaptation compensating for limited neck and head mobility. J. Comp. Neurol., 525:2484-2498, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  12. Sphenopalatine ganglion treatment with radiofrequency in a Sluder syndrome young patient

    OpenAIRE

    Carmelo Costa; Marilina Schembari

    2014-01-01

    Sluder's neuralgia or sphenopalatine ganglion neuralgia is a pain syndrome first described by Sluder in 1908. The clinical picture is characterised by pain starting around the eye and the route of nose. Typically the pain is accompanied by parasympathetic disautonomic signs such as lacrimation and/or rhinorrhea. However, many official headache classifications do not mention the Sluder's neuralgia at all, which is instead classified as a cluster headache (CH). In case of resistance to pharmaco...

  13. Psychosocial Adaptation to Visual Impairment and Its Relationship to Depressive Affect in Older Adults with Age-Related Macular Degeneration

    Science.gov (United States)

    Tolman, Jennifer; Hill, Robert D.; Kleinschmidt, Julia J.; Gregg, Charles H.

    2005-01-01

    Purpose: In this study we examined psychosocial adaptation to vision loss and its relationship to depressive symptomatology in legally blind older adults with age-related macular degeneration (ARMD). Design and Methods: The 144 study participants were outpatients of a large regional vision clinic that specializes in the diagnosis and treatment of…

  14. Sensitive absorption detection for micro-column liquid chromatography by ultraviolet forward-scattering degenerate four-wave mixing.

    NARCIS (Netherlands)

    de Beer, T.; Beso, P.; Velthorst, N.H.; Brinkman, U.A.T.; Gooijer, C.; Hoornweg, G.Ph.

    1999-01-01

    The performance of forward-scattering degenerate four-wave mixing (F-D4WM) in the mid-ultraviolet (UV) region (351nm) as a detection technique for micro-column liquid chromatography (μLC) is studied, using nitro-substituted polycyclic aromatic hydrocarbons (NO

  15. Frequency metrology in quantum degenerate helium

    Directory of Open Access Journals (Sweden)

    Vassen Wim

    2013-08-01

    Full Text Available We have measured the absolute frequency of the 1557-nm doubly forbidden transition between the two metastable states of helium, 2 3S1 (lifetime 8000 s and 2 1S0 (lifetime 20 ms, with 1 kHz precision. With an Einstein coefficient of 10−7 s−1 this is one of weakest optical transitions ever measured. The measurement was performed in a Bose-Einstein condensate of 4He* as well as in a Degenerate Fermi Gas of 3He*, trapped in a crossed dipole trap. From the isotope shift we deduced the nuclear charge radius difference between the α-particle and the helion. Our value differs by 4σ with a very recent result obtained on the 2 3S → 2 3P transition.

  16. Nearly degenerate neutrinos, Supersymmetry and radiative corrections

    CERN Document Server

    Casas, J A; Ibarra, Alejandro; Navarro, I

    2000-01-01

    If neutrinos are to play a relevant cosmological role, they must be essentially degenerate with a mass matrix of the bimaximal mixing type. We study this scenario in the MSSM framework, finding that if neutrino masses are produced by a see-saw mechanism, the radiative corrections give rise to mass splittings and mixing angles that can accommodate the atmospheric and the (large angle MSW) solar neutrino oscillations. This provides a natural origin for the $\\Delta m^2_{sol} << \\Delta m^2_{atm}$ hierarchy. On the other hand, the vacuum oscillation solution to the solar neutrino problem is always excluded. We discuss also in the SUSY scenario other possible effects of radiative corrections involving the new neutrino Yukawa couplings, including implications for triviality limits on the Majorana mass, the infrared fixed point value of the top Yukawa coupling, and gauge coupling and bottom-tau unification.

  17. Prevention of Age-Related Macular Degeneration.

    Science.gov (United States)

    Singh, Niharika; Srinivasan, Sangeetha; Muralidharan, Vinata; Roy, Rupak; V, Jayprakash; Raman, Rajiv

    2017-01-01

    Age-related macular degeneration (AMD) compromises quality of life. However, the available therapeutic options are limited. This has led to the identification of modifiable risk factors to prevent the development or alter the natural course and prognosis of AMD. The identification and modification of risk factors has the potential for greater public health impact on reducing morbidity from AMD. Likewise, identifying the imaging clues and genetic clues could serve as a guide to recognizing the propensity for progression to severe and end stages of the disease. Several attempts, both successful and unsuccessful, have been made for interventions that could delay the progression of AMD. Of these, pharmacological interventions have shown promising results. The Age-Related Eye Disease Study 1 and 2 have shown the beneficial role of antioxidants in a selected group of patients. Copyright 2017 Asia-Pacific Academy of Ophthalmology.

  18. A COMPUTATIONAL MODEL OF MOTOR NEURON DEGENERATION

    Science.gov (United States)

    Le Masson, Gwendal; Przedborski, Serge; Abbott, L.F.

    2014-01-01

    SUMMARY To explore the link between bioenergetics and motor neuron degeneration, we used a computational model in which detailed morphology and ion conductance are paired with intracellular ATP production and consumption. We found that reduced ATP availability increases the metabolic cost of a single action potential and disrupts K+/Na+ homeostasis, resulting in a chronic depolarization. The magnitude of the ATP shortage at which this ionic instability occurs depends on the morphology and intrinsic conductance characteristic of the neuron. If ATP shortage is confined to the distal part of the axon, the ensuing local ionic instability eventually spreads to the whole neuron and involves fasciculation-like spiking events. A shortage of ATP also causes a rise in intracellular calcium. Our modeling work supports the notion that mitochondrial dysfunction can account for salient features of the paralytic disorder amyotrophic lateral sclerosis, including motor neuron hyperexcitability, fasciculation, and differential vulnerability of motor neuron subpopulations. PMID:25088365

  19. Degenerate R-S perturbation theory

    Science.gov (United States)

    Hirschfelder, J. O.; Certain, P. R.

    1973-01-01

    A concise, systematic procedure is given for determining the Rayleigh-Schrodinger energies and wave functions of degenerate states to arbitrarily high orders even when the degeneracies of the various states are resolved in arbitrary orders. The procedure is expressed in terms of an iterative cycle in which the energy through the (2n+1)st order is expressed in terms of the partially determined wave function through the n-th order. Both a direct and an operator derivation are given. The two approaches are equivalent and can be transcribed into each other. The direct approach deals with the wave functions (without the use of formal operators) and has the advantage that it resembles the usual treatment of nondegenerate perturbations and maintains close contact with the basic physics. In the operator approach, the wave functions are expressed in terms of infinite order operators which are determined by the successive resolution of the space of the zeroth order functions.

  20. Conjunctival intraepithelial neoplasia with corneal furrow degeneration

    Directory of Open Access Journals (Sweden)

    Pukhraj Rishi

    2014-01-01

    Full Text Available A 68-year-old man presented with redness of left eye since six months. Examination revealed bilateral corneal furrow degeneration. Left eye lesion was suggestive of conjunctival squamous cell carcinoma, encroaching on to cornea. Anterior segment optical coherence tomography (AS-OCT confirmed peripheral corneal thinning. Fluorescein angiography confirmed intrinsic vascularity of lesion. Patient was managed with "no touch" surgical excision, dry keratectomy without alcohol, cryotherapy, and primary closure. Pathologic examination of removed tissue confirmed clinical diagnosis. Management of this particular case required modification of standard treatment protocol. Unlike the alcohol-assisted technique of tumor dissection described, ethyl alcohol was not used for risk of corneal perforation due to underlying peripheral corneal thinning. Likewise, topical steroids were withheld in the post-operative period. Three weeks post-operatively, left eye was healing well. Hence, per-operative usage of absolute alcohol and post-operative use of topical steroids may be best avoided in such eyes.

  1. Formation of Degenerate Band Gaps in Layered Systems

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    Alexey P. Vinogradov

    2012-06-01

    Full Text Available In the review, peculiarities of spectra of one-dimensional photonic crystals made of anisotropic and/or magnetooptic materials are considered. The attention is focused on band gaps of a special type—the so called degenerate band gaps which are degenerate with respect to polarization. Mechanisms of formation and properties of these band gaps are analyzed. Peculiarities of spectra of photonic crystals that arise due to the linkage between band gaps are discussed. Particularly, it is shown that formation of a frozen mode is caused by linkage between Brillouin and degenerate band gaps. Also, existence of the optical Borrmann effect at the boundaries of degenerate band gaps and optical Tamm states at the frequencies of degenerate band gaps are analyzed.

  2. Computer assisted characterization of cervical intervertebral disc degeneration in MRI

    Science.gov (United States)

    Michopoulou, S.; Boniatis, I.; Costaridou, L.; Cavouras, D.; Panagiotopoulos, E.; Panayiotakis, G.

    2009-05-01

    A texture-based pattern recognition system is proposed for the automatic characterization of cervical intervertebral disc degeneration from saggital magnetic resonance images of the spine. A case sample of 50 manually segmented ROIs, corresponding to 25 normal and 25 degenerated discs, was analyzed and textural features were generated from each disc-ROI. Student's t-test verified the existence of statistically significant differences between textural feature values generated from normal and degenerated discs. This finding is indicative of disc image texture differentiation due to the degeneration of the disc. The generated features were employed in the design of a pattern recognition system based on the Least Squares Minimum Distance classifier. The system achieved a classification accuracy of 94{%} and it may be of value to physicians for the assessment of cervical intervertebral disc degeneration in MRI.

  3. [Lattice degeneration of the peripheral retina: ultrastructural study].

    Science.gov (United States)

    Bec, P; Malecaze, F; Arne, J L; Mathis, A

    1985-01-01

    The ultrastructural study of a case of snail track degeneration shows the presence of lipid inclusions in both the glial and the macrophage cells in every layer of the retina, and the existence of intraretinal fibers different from collagen fibers appearing to be glial filaments similar to those found in astrocytic gliomes and to the Rosenthal fibers observed in senile nervous cells. Other features were thinning of the retina and absence of blood vessels in the retina. There are no abnormalities of the vitreo-retinal juncture. All the lesions are in agreement with those observed by Daicker [Ophthalmologica, Basel 165: 360-365, 1972; Klin. Mbl. Augenheilk. 172: 581-583, 1978] with some differences, however. They are different from those found in lattice degeneration. They show that snail track degeneration is a specific form of peripheral retinal degeneration which is quite different from lattice degeneration and must not be considered similar.

  4. The effect of kyphoscoliosis on intervertebral disc degeneration in dogs.

    Science.gov (United States)

    Faller, Kiterie; Penderis, Jacques; Stalin, Catherine; Guevar, Julien; Yeamans, Carmen; Gutierrez-Quintana, Rodrigo

    2014-06-01

    In people, abnormalities in vertebral column conformation, such as kyphoscoliosis, induce degenerative changes in adjacent intervertebral disc (IVD) structure and composition. It was hypothesised that canine IVDs adjacent to a vertebral malformation undergo early degeneration. In a blinded retrospective study, thoracic IVD degeneration was evaluated in 14 dogs on magnetic resonance images using Pfirrmann's grade. IVDs adjacent to a vertebral malformation had higher grades of degeneration than non-adjacent IVDs (P < 0.0001). There was an age-dependency, with dogs between 1 and 4 years showing higher grade of degeneration in adjacent than non-adjacent IVDs (P < 0.0001). Conversely, in older dogs, all IVDs - including the non-adjacents - showed degenerative signs, possibly due to normal aging. These results suggest that congenital vertebral malformation results in early degeneration of adjacent IVDs. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. The developing and restructuring superior cervical ganglion of guinea pigs (Cavia porcellus var. albina).

    Science.gov (United States)

    Toscano, Cauê Pereira; de Melo, Mariana Pereira; Matera, Júlia Maria; Loesch, Andrzej; Ribeiro, Antonio Augusto Coppi Maciel

    2009-06-01

    Post-natal development comprises both maturation (from newborn to adult) and ageing (from adult to senility) and, during this phase, several adaptive mechanisms occur in sympathetic ganglia, albeit they are not fully understood. Therefore, the present study aimed at detecting whether post-natal development would exert any effect on the size and number of a guinea pig's superior cervical ganglion (SCG) neurons. Twenty right SCGs from male subjects were used at four ages, i.e. newborn (7 days), young (30 days), adult (7 months) and old animals (50 months). Using design-based stereological methods the volume of ganglion and the total number of mononucleate and binucleate neurons were estimated. Furthermore, the mean perikaryal volume of mononucleate and binucleate neurons was estimated using the vertical nucleator. The main findings of this study were a combination of post-natal-dependent increases and decreases in some variables: (i) 27% increase in ganglion volume, (ii) 24% and 43% decreases in the total number of mono and binucleate neurons, respectively, and (iii) 27.5% and 40% decreases in the mean perikaryal volume of mono and binucleate neurons, respectively. Despite the fall in neuron numbers found here, post-natal development is not only associated with neuron loss, but also embraces other structural adaptive mechanisms, which are discussed in this paper.

  6. The Role of Cyclooxygenase in Multiplication and Reactivation of HSV-1 in Vestibular Ganglion Neurons

    Directory of Open Access Journals (Sweden)

    Yuehong Liu

    2014-01-01

    Full Text Available Reactivation of latent herpes simplex type 1 (HSV-1 and nerve inflammation have been shown to be involved in vertigo-related vestibular pathogenesis. Treatments of such diseases have been less than perfect. Nonsteroidal anti-inflammatory drugs (NSAIDs have been reported to suppress reactivation of HSV-1 in trigeminal ganglions. However, whether this drug can affect reactivation of HSV-1 in vestibular ganglions is unclear. Due to the difficulties of constructing in vivo animal models, in this study, we developed a vestibular ganglion culture system, in which vestibular neurons were latently or lytically infected with HSV-1. Indomethacin and celecoxib were selected to measure their effects on HSV-1. Trichostatin A was used to reactivate HSV-1 in latently infected neurons. Cycloxygenase-2, which is the target of NSAIDs, was induced by HSV-1 in the lytically infected cultures, with an increase of 14-fold. Although it appeared that indomethacin and celecoxib showed limited but concentration-dependent inhibition effects on viral production under our condition, indomethacin decreased reactivation rate of HSV-1 by about 20%. Though more in vitro or in vivo studies are needed to confirm the effects of the drugs, our study may provide a potential way to investigate the mechanism of HSV-related vestibular pathogenesis as well as new treatments of vertigo-related diseases.

  7. A Guyon's canal ganglion presenting as occupational overuse syndrome: A case report

    Directory of Open Access Journals (Sweden)

    Hennessy Michael J

    2008-02-01

    Full Text Available Abstract Background Occupational overuse syndrome (OOS can present as Guyon's canal syndrome in computer keyboard users. We report a case of Guyon's canal syndrome caused by a ganglion in a computer user that was misdiagnosed as OOS. Case presentation A 54-year-old female secretary was referred with a six-month history of right little finger weakness and difficulty with adduction. Prior to her referral, she was diagnosed by her general practitioner and physiotherapist with a right ulnar nerve neuropraxia at the level of the Guyon's canal. This was thought to be secondary to computer keyboard use and direct pressure exerted on a wrist support. There was obvious atrophy of the hypothenar eminence and the first dorsal interosseous muscle. Both Froment's and Wartenberg's signs were positive. A nerve conduction study revealed that both the abductor digiti minimi and the first dorsal interosseus muscles showed prolonged motor latency. Ulnar conduction across the right elbow was normal. Ulnar sensory amplitude across the right wrist to the fifth digit was reduced while the dorsal cutaneous nerve response was normal. Magnetic resonance imaging of the right wrist showed a ganglion in Guyon's canal. Decompression of the Guyon's canal was performed and histological examination confirmed a ganglion. The patient's symptoms and signs resolved completely at four-month follow-up. Conclusion Clinical history, occupational history and examination alone could potentially lead to misdiagnosis of OOS when a computer user presents with these symptoms and we recommend that nerve conduction or imaging studies be performed.

  8. Adult human nasal mesenchymal-like stem cells restore cochlear spiral ganglion neurons after experimental lesion.

    Science.gov (United States)

    Bas, Esperanza; Van De Water, Thomas R; Lumbreras, Vicente; Rajguru, Suhrud; Goss, Garrett; Hare, Joshua M; Goldstein, Bradley J

    2014-03-01

    A loss of sensory hair cells or spiral ganglion neurons from the inner ear causes deafness, affecting millions of people. Currently, there is no effective therapy to repair the inner ear sensory structures in humans. Cochlear implantation can restore input, but only if auditory neurons remain intact. Efforts to develop stem cell-based treatments for deafness have demonstrated progress, most notably utilizing embryonic-derived cells. In an effort to bypass limitations of embryonic or induced pluripotent stem cells that may impede the translation to clinical applications, we sought to utilize an alternative cell source. Here, we show that adult human mesenchymal-like stem cells (MSCs) obtained from nasal tissue can repair spiral ganglion loss in experimentally lesioned cochlear cultures from neonatal rats. Stem cells engraft into gentamicin-lesioned organotypic cultures and orchestrate the restoration of the spiral ganglion neuronal population, involving both direct neuronal differentiation and secondary effects on endogenous cells. As a physiologic assay, nasal MSC-derived cells engrafted into lesioned spiral ganglia demonstrate responses to infrared laser stimulus that are consistent with those typical of excitable cells. The addition of a pharmacologic activator of the canonical Wnt/β-catenin pathway concurrent with stem cell treatment promoted robust neuronal differentiation. The availability of an effective adult autologous cell source for inner ear tissue repair should contribute to efforts to translate cell-based strategies to the clinic.

  9. Ganglion cell adaptability: does the coupling of horizontal cells play a role?

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    Karin Dedek

    Full Text Available BACKGROUND: The visual system can adjust itself to different visual environments. One of the most well known examples of this is the shift in spatial tuning that occurs in retinal ganglion cells with the change from night to day vision. This shift is thought to be produced by a change in the ganglion cell receptive field surround, mediated by a decrease in the coupling of horizontal cells. METHODOLOGY/PRINCIPAL FINDINGS: To test this hypothesis, we used a transgenic mouse line, a connexin57-deficient line, in which horizontal cell coupling was abolished. Measurements, both at the ganglion cell level and the level of behavioral performance, showed no differences between wild-type retinas and retinas with decoupled horizontal cells from connexin57-deficient mice. CONCLUSION/SIGNIFICANCE: This analysis showed that the coupling and uncoupling of horizontal cells does not play a dominant role in spatial tuning and its adjustability to night and day light conditions. Instead, our data suggest that another mechanism, likely arising in the inner retina, must be responsible.

  10. Investigating the expression of metabotropic glutamate receptors in trigeminal ganglion neurons and satellite glial cells: implications for craniofacial pain.

    Science.gov (United States)

    Boye Larsen, Dennis; Ingemann Kristensen, Gunda; Panchalingam, Vinodenee; Laursen, Jens Christian; Nørgaard Poulsen, Jeppe; Skallerup Andersen, Maria; Kandiah, Aginsha; Gazerani, Parisa

    2014-08-01

    Previous studies have demonstrated that various subtypes of the metabotropic glutamate receptors (mGluRs) are expressed in the dorsal root ganglion (DRG) of the peripheral nervous system (PNS), implicating that glutamate potentially contributes to sensory transmission through these receptors. While mGluR expression has been investigated largely in the DRG, the present study focused on mGluR expression on neurons and satellite glial cells (SGCs) of the trigeminal ganglion (TG). To address the presence of mGluRs in rat TG neurons and their corresponding SGCs, the trigeminal ganglia from six adult male Wistar rats were isolated and immunohistochemistry and immunocytochemistry were performed. The expression of mGluR1α-, mGluR2/3- and mGluR8 on TG neurons and SGCs was investigated in tissue slices and isolated cells. 35.1 ± 6.0% of the TG neurons were positive for mGluR1α, whereas 39.9 ± 7.7% and 55.5 ± 6.3% were positive for mGluR2/3 and mGluR8, respectively. Immunoreactive neurons expressing mGluRs were mainly medium- to large sized, with a smaller population of small-sized neurons showing immunoreactivity. The SGCs showed immunoreactivity toward mGluR1α and mGluR8, but not mGluR2/3, both in the tissue and in isolated cells. Findings from the present study showed that trigeminal neurons express mGluR1α, mGluR2/3 and mGluR8, while SGCs only express mGluR1α and mGluR8. This novel evidence may advance investigations on a possible role of mGluRs in relation to trigeminal pain transmission within the craniofacial region.

  11. Distribution of ganglionic sympathetic neurons supplying the subcutaneous, perirenal and mesentery fat tissue depots in the pig.

    Science.gov (United States)

    Czaja, Krzysztof; Kraeling, Robert; Klimczuk, Magdalena; Franke-Radowiecka, Amelia; Sienkiewicz, Waldemar; Lakomy, Mirosław

    2002-01-01

    Previous morphological studies revealed that the adipose tissue is innervated by adrenergic nerve fibers. Furthermore, physiological studies showed that the metabolism of adipose tissue is controlled by the adrenergic component of the nervous system. However, nothing is known on the sources of innervation of different fat tissue depots. Therefore, we decided to study the distribution of ganglionic sympathetic neurons innervating adipose tissue in the pig by means of a retrograde tracing method. We used 9 male and 9 female pigs of approximately 50 kg body weight. The retrograde tracer, Fast Blue (FB), was injected into the subcutaneous, perirenal and mesentery fat tissue depots. Results of the present study showed that numerous centers of the sympathetic nervous system innervate adipose tissue in the pig. FB+ neurons projecting to the subcutaneous fat tissue were placed in the thoraco-lumbar region of the sympathetic chain ganglia (SChG). However, neurons supplying perirenal and mesentery fat tissue depots were found in both the SChG and prevertebral ganglia (PVG). We conclude that different adipose tissue depots (subcutaneous, perirenal and mesentery) have different sources of innervation and that there is no significant difference in the distribution of neurons innervating adipose tissue in male and female pigs.

  12. Light-induced retinal degeneration causes a transient downregulation of melanopsin in the rat retina.

    Science.gov (United States)

    García-Ayuso, Diego; Galindo-Romero, Caridad; Di Pierdomenico, Johnny; Vidal-Sanz, Manuel; Agudo-Barriuso, Marta; Villegas Pérez, María P

    2017-08-01

    In this work we study the effects of an acute light-induced retinal degeneration on the population of melanopsin positive retinal ganglion cells (m + RGCs) and the expression of the melanopsin protein in the retina. The m + RGCs may be more resistant than other RGCs to lesion, but the effects of an acute light exposure in this population are unknown. Albino rats were exposed to white light (3000 lux) continuously for 48 h and processed 0, 3, 7 or 30 days after light exposure (ALE). Whole-mounted retinas were immunodetected with antibodies against melanopsin, Brn3a, and rhodopsin to study the populations of m + RGC, Brn3a + RGC and rods (which are the most abundant photoreceptors in the rat retina). Three days ALE there was substantial rod loss in an arciform area of the superior retina and with time this loss expanded in the form of rings all throughout the retina. Light exposure did not affect the number of Brn3a + RGCs but diminished the numbers of m + RGCs. Immediately ALE there was a significant decrease in the mean number of immunodetected m + RGCs that was more marked in the superior retina. Later, the number of m + RGCs increased progressively and reached normal values one month ALE. Western blot analysis showed that melanopsin expression down-regulates shortly ALE and recovers thereafter, in accordance with the anatomical data. This study demonstrates that there is a transient downregulation of melanopsin expression in the RGCs during the first month ALE. Further studies would be needed to clarify the long-term effect of light exposure on the m + RGC population. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  13. Hearing impairment in the P23H-1 retinal degeneration rat model

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    Jorge V. Sotoca

    2014-09-01

    Full Text Available The transgenic P23H line 1 (P23H-1 rat expresses a variant of rhodopsin with a mutation that leads to loss of visual function. This rat strain is an experimental model usually employed to study photoreceptor degeneration. Although the mutated protein should not interfere with other sensory functions, observing severe loss of auditory reflexes in response to natural sounds led us to study auditory brain response (ABR recording. Animals were separated into different hearing levels following the response to natural stimuli (hand clapping and kissing sounds. Of all the analyzed animals, 25.9% presented auditory loss before 50 days of age (P50 and 45% were totally deaf by P200. ABR recordings showed that all the rats had a higher hearing threshold than the control Sprague-Dawley (SD rats, which was also higher than any other rat strains. The integrity of the central and peripheral auditory pathway was analyzed by histology and immunocytochemistry. In the cochlear nucleus (CN, statistical differences were found between SD and P23H-1 rats in VGluT1 distribution, but none were found when labeling all the CN synapses with anti-Syntaxin. This finding suggests anatomical and/or molecular abnormalities in the auditory downstream pathway. The inner ear of the hypoacusic P23H-1 rats showed several anatomical defects, including loss and disruption of hair cells and spiral ganglion neurons. All these results can explain, at least in part, how hearing impairment can occur in a high percentage of P23H-1 rats. P23H-1 rats may be considered an experimental model with visual and auditory dysfunctions in future research.

  14. Low Nitric Oxide Synthases (NOS) in Eyes with Age-related Macular Degeneration (AMD)

    Science.gov (United States)

    Bhutto, Imran A.; Baba, Takayuki; Merges, Carol; McLeod, D. Scott; Lutty, Gerard A.

    2009-01-01

    Nitric oxide (NO) production by vascular endothelium is important in regulation of blood flow. Reduced production of NO can adversely affect blood flow and other vascular functions. We investigated the expression of three nitric oxide synthase (NOS) isoforms in retina and choroid of aged human eyes and eyes with AMD. Alkaline phosphatase immunohistochemistry was performed using antibodies against inducible (iNOS), neuronal (nNOS), and endothelial (eNOS) NOSs on cryopreserved sections from aged control donor eyes (n= 13) and eyes with AMD (n= 22). CD34 antibody was used as an endothelial cell (EC) marker. Three independent masked observers scored the intensity of the immunohistochemical reaction product. Mean scores from the aged control and AMD eyes were statistically compared. In aged control retinas, nNOS was in ganglion cells (RGCs) and neurons of both nuclear layers. In choroid, perivascular nerve fibers and retinal pigment epithelial (RPE) cells were nNOS+. eNOS and iNOS were confined to the retinal and choroidal vascular ECs. Some cells presumably melanocytes or dendritic cells in choroid were also eNOS+. In AMD eyes, nNOS was significantly lower in RGCs, neurons, retinal vessels and RPE (p≤0.05) compared to the aged control eyes. iNOS and eNOS showed no significant differences between aged control and AMD eyes except that there was significantly less eNOS in choroidal arteries (p=0.006) and choroidal cells (p=0.03) of AMD eyes. Although NO was not measured directly, these findings suggest that there is less NO produced in AMD eyes. The decrease in retinal nNOS in AMD eyes is probably related to neuronal degeneration. The decrease in nNOS and eNOS in AMD choroid could be associated with vasoconstriction and hemodynamic changes. PMID:19836390

  15. Efficacy of Noninvasive Stellate Ganglion Blockade Performed Using Physical Agent Modalities in Patients with Sympathetic Hyperactivity-Associated Disorders: A Systematic Review and Meta-Analysis.

    Directory of Open Access Journals (Sweden)

    Chun-De Liao

    Full Text Available Stellate ganglion blockade (SGB is mainly used to relieve symptoms of neuropathic pain in conditions such as complex regional pain syndrome and has several potential complications. Noninvasive SGB performed using physical agent modalities (PAMs, such as light irradiation and electrical stimulation, can be clinically used as an alternative to conventional invasive SGB. However, its application protocols vary and its clinical efficacy remains controversial. This study investigated the use of noninvasive SGB for managing neuropathic pain or other disorders associated with sympathetic hyperactivity.We performed a comprehensive search of the following online databases: Medline, PubMed, Excerpta Medica Database, Cochrane Library Database, Ovid MEDLINE, Europe PubMed Central, EBSCOhost Research Databases, CINAHL, ProQuest Research Library, Physiotherapy Evidence Database, WorldWideScience, BIOSIS, and Google Scholar. We identified and included quasi-randomized or randomized controlled trials reporting the efficacy of SGB performed using therapeutic ultrasound, transcutaneous electrical nerve stimulation, light irradiation using low-level laser therapy, or xenon light or linearly polarized near-infrared light irradiation near or over the stellate ganglion region in treating complex regional pain syndrome or disorders requiring sympatholytic management. The included articles were subjected to a meta-analysis and risk of bias assessment.Nine randomized and four quasi-randomized controlled trials were included. Eleven trials had good methodological quality with a Physiotherapy Evidence Database (PEDro score of ≥6, whereas the remaining two trials had a PEDro score of <6. The meta-analysis results revealed that the efficacy of noninvasive SGB on 100-mm visual analog pain score is higher than that of a placebo or active control (weighted mean difference, -21.59 mm; 95% CI, -34.25, -8.94; p = 0.0008.Noninvasive SGB performed using PAMs effectively relieves

  16. Neuroprotection by α2-Adrenergic Receptor Stimulation after Excitotoxic Retinal Injury: A Study of the Total Population of Retinal Ganglion Cells and Their Distribution in the Chicken Retina.

    Science.gov (United States)

    Galindo-Romero, Caridad; Harun-Or-Rashid, Mohammad; Jiménez-López, Manuel; Vidal-Sanz, Manuel; Agudo-Barriuso, Marta; Hallböök, Finn

    2016-01-01

    We have studied the effect of α2-adrenergic receptor stimulation on the total excitotoxically injured chicken retinal ganglion cell population. N-methyl-D-aspartate (NMDA) was intraocularly injected at embryonic day 18 and Brn3a positive retinal ganglion cells (Brn3a+ RGCs) were counted in flat-mounted retinas using automated routines. The number and distribution of the Brn3a+ RGCs were analyzed in series of normal retinas from embryonic day 8 to post-hatch day 11 retinas and in retinas 7 or 14 days post NMDA lesion. The total number of Brn3a+ RGCs in the post-hatch retina was approximately 1.9x106 with a density of approximately 9.2x103 cells/mm2. The isodensity maps of normal retina showed that the density decreased with age as the retinal size increased. In contrast to previous studies, we did not find any specific region with increased RGC density, rather the Brn3a+ RGCs were homogeneously distributed over the central retina with decreasing density in the periphery and in the region of the pecten oculli. Injection of 5-10 μg NMDA caused 30-50% loss of Brn3a+ cells and the loss was more severe in the dorsal than in the ventral retina. Pretreatment with brimonidine reduced the loss of Brn3a+ cells both 7 and 14 days post lesion and the protective effect was higher in the dorsal than in the ventral retina. We conclude that α2-adrenergic receptor stimulation reduced the impact of the excitotoxic injury in chicken similarly to what has been shown in mammals. Furthermore, the data show that the RGCs are evenly distributed over in the retina, which challenges previous results that indicate the presence of specific high RGC-density regions of the chicken retina.

  17. Neuroprotection by α2-Adrenergic Receptor Stimulation after Excitotoxic Retinal Injury: A Study of the Total Population of Retinal Ganglion Cells and Their Distribution in the Chicken Retina

    Science.gov (United States)

    Galindo-Romero, Caridad; Harun-Or-Rashid, Mohammad; Jiménez-López, Manuel; Vidal-Sanz, Manuel; Agudo-Barriuso, Marta

    2016-01-01

    We have studied the effect of α2-adrenergic receptor stimulation on the total excitotoxically injured chicken retinal ganglion cell population. N-methyl-D-aspartate (NMDA) was intraocularly injected at embryonic day 18 and Brn3a positive retinal ganglion cells (Brn3a+ RGCs) were counted in flat-mounted retinas using automated routines. The number and distribution of the Brn3a+ RGCs were analyzed in series of normal retinas from embryonic day 8 to post-hatch day 11 retinas and in retinas 7 or 14 days post NMDA lesion. The total number of Brn3a+ RGCs in the post-hatch retina was approximately 1.9x106 with a density of approximately 9.2x103 cells/mm2. The isodensity maps of normal retina showed that the density decreased with age as the retinal size increased. In contrast to previous studies, we did not find any specific region with increased RGC density, rather the Brn3a+ RGCs were homogeneously distributed over the central retina with decreasing density in the periphery and in the region of the pecten oculli. Injection of 5–10 μg NMDA caused 30–50% loss of Brn3a+ cells and the loss was more severe in the dorsal than in the ventral retina. Pretreatment with brimonidine reduced the loss of Brn3a+ cells both 7 and 14 days post lesion and the protective effect was higher in the dorsal than in the ventral retina. We conclude that α2-adrenergic receptor stimulation reduced the impact of the excitotoxic injury in chicken similarly to what has been shown in mammals. Furthermore, the data show that the RGCs are evenly distributed over in the retina, which challenges previous results that indicate the presence of specific high RGC-density regions of the chicken retina. PMID:27611432

  18. Efficacy of Noninvasive Stellate Ganglion Blockade Performed Using Physical Agent Modalities in Patients with Sympathetic Hyperactivity-Associated Disorders: A Systematic Review and Meta-Analysis.

    Science.gov (United States)

    Liao, Chun-De; Tsauo, Jau-Yih; Liou, Tsan-Hon; Chen, Hung-Chou; Rau, Chi-Lun

    2016-01-01

    Stellate ganglion blockade (SGB) is mainly used to relieve symptoms of neuropathic pain in conditions such as complex regional pain syndrome and has several potential complications. Noninvasive SGB performed using physical agent modalities (PAMs), such as light irradiation and electrical stimulation, can be clinically used as an alternative to conventional invasive SGB. However, its application protocols vary and its clinical efficacy remains controversial. This study investigated the use of noninvasive SGB for managing neuropathic pain or other disorders associated with sympathetic hyperactivity. We performed a comprehensive search of the following online databases: Medline, PubMed, Excerpta Medica Database, Cochrane Library Database, Ovid MEDLINE, Europe PubMed Central, EBSCOhost Research Databases, CINAHL, ProQuest Research Library, Physiotherapy Evidence Database, WorldWideScience, BIOSIS, and Google Scholar. We identified and included quasi-randomized or randomized controlled trials reporting the efficacy of SGB performed using therapeutic ultrasound, transcutaneous electrical nerve stimulation, light irradiation using low-level laser therapy, or xenon light or linearly polarized near-infrared light irradiation near or over the stellate ganglion region in treating complex regional pain syndrome or disorders requiring sympatholytic management. The included articles were subjected to a meta-analysis and risk of bias assessment. Nine randomized and four quasi-randomized controlled trials were included. Eleven trials had good methodological quality with a Physiotherapy Evidence Database (PEDro) score of ≥6, whereas the remaining two trials had a PEDro score of <6. The meta-analysis results revealed that the efficacy of noninvasive SGB on 100-mm visual analog pain score is higher than that of a placebo or active control (weighted mean difference, -21.59 mm; 95% CI, -34.25, -8.94; p = 0.0008). Noninvasive SGB performed using PAMs effectively relieves pain of

  19. A giant uterine myometrium cyst mimicking an ovarian cyst in pregnancy: An uncommon presentation of hydropic degeneration of uterine fibroid

    Directory of Open Access Journals (Sweden)

    Elsayed Elbadawy Awad

    2015-06-01

    Full Text Available Myometrial cysts of the uterus are extremely rare. Uterine leiomyomas commonly undergo degenerative changes, which can lead to variable imaging features. Diffuse hydropic change is an unusual form that presents a considerable diagnostic challenge to both radiologists and pathologists. A 27-year old nulliparous patient admitted to our hospital for antenatal care and left sided pelvic pain. Transvaginal ultrasonographic examination revealed a 20 cm intramural cystic lesion in the left region of the corpus uteri suspicious of degenerated myoma. Repeated aspiration was done. Spontaneous abortion occurred in the first trimester. Rapid distension of the abdomen despite repeated aspirations occurred. MRI revealed degenerated myoma. Ultrasound performed one day before surgery revealed a turbid content instead of the clear fluid. Laparotomy was performed revealing a huge interstitial myoma with bloody collection inside so, myomectomy was performed. Histopathology showed hydropic degenerated myoma. Although fibroids usually have a characteristic sonographic appearance, degenerating myomas have variable patterns and can pose a diagnostic dilemma. Extensive cystic degeneration can mimic an ovarian tumour.

  20. Strychnine, but not PMBA, inhibits neuronal nicotinic acetylcholine receptors expressed by rabbit retinal ganglion cells.

    Science.gov (United States)

    Renna, J M; Strang, C E; Amthor, F R; Keyser, K T

    2007-01-01

    Strychnine is considered a selective competitive antagonist of glycine gated Cl- channels (Saitoh et al., 1994) and studies have used strychnine at low micromolar concentrations to study the role of glycine in rabbit retina (Linn, 1998; Protti et al., 2005). However, other studies have shown that strychnine, in the concentrations commonly used, is also a potent competitive antagonist of alpha7 nicotinic acetylcholine receptors (nAChRs; Matsubayashi et al., 1998). We tested the effects of low micromolar concentrations of strychnine and 3-[2'-phosphonomethyl[1,1'-biphenyl]-3-yl] alanine (PMBA), a specific glycine receptor blocker (Saitoh et al., 1994; Hosie et al., 1999) on the activation of both alpha7 nAChRs on retinal ganglion cells and on ganglion cell responses to a light flash. Extracellular recordings were obtained from ganglion cells in an isolated retina/choroid preparation and 500 microM choline was used as an alpha7 agonist (Alkondon et al., 1997). We recorded from brisk sustained and brisk transient OFF cells, many of which have been previously shown to have alpha7 receptors (Strang et al., 2005). Further, we tested the effect of strychnine, PMBA and alpha-bungarotoxin on the binding of tetramethylrhodamine alpha-bungarotoxin in the inner plexiform layer. Our data indicates that strychnine, at doses as low as 1.0 microM, can inhibit the alpha7 nAChR-mediated response to choline, but PMBA at concentrations as high as 0.4 microM does not. Binding studies show strychnine and alpha-bungarotoxin inhibit binding of labeled alpha-bungarotoxin in the IPL. Thus, the effects of strychnine application may be to inhibit glycine receptors expressed by ganglion cell or to inhibit amacrine cell alpha7 nAChRs, both of which would result in an increase in the ganglion cell responses. Further research will be required to disentangle the effects of strychnine previously believed to be caused by a single mechanism of glycine receptor inhibition.

  1. Classification of wet aged related macular degeneration using optical coherence tomographic images

    Science.gov (United States)

    Haq, Anam; Mir, Fouwad Jamil; Yasin, Ubaid Ullah; Khan, Shoab A.

    2013-12-01

    Wet Age related macular degeneration (AMD) is a type of age related macular degeneration. In order to detect Wet AMD we look for Pigment Epithelium detachment (PED) and fluid filled region caused by choroidal neovascularization (CNV). This form of AMD can cause vision loss if not treated in time. In this article we have proposed an automated system for detection of Wet AMD in Optical coherence tomographic (OCT) images. The proposed system extracts PED and CNV from OCT images using segmentation and morphological operations and then detailed feature set are extracted. These features are then passed on to the classifier for classification. Finally performance measures like accuracy, sensitivity and specificity are calculated and the classifier delivering the maximum performance is selected as a comparison measure. Our system gives higher performance using SVM as compared to other methods.

  2. Astrocytes and Müller Cell Alterations During Retinal Degeneration in a Transgenic Rat Model of Retinitis Pigmentosa

    Science.gov (United States)

    Fernández-Sánchez, Laura; Lax, Pedro; Campello, Laura; Pinilla, Isabel; Cuenca, Nicolás

    2015-01-01

    Purpose: Retinitis pigmentosa includes a group of progressive retinal degenerative diseases that affect the structure and function of photoreceptors. Secondarily to the loss of photoreceptors, there is a reduction in retinal vascularization, which seems to influence the cellular degenerative process. Retinal macroglial cells, astrocytes, and Müller cells provide support for retinal neurons and are fundamental for maintaining normal retinal function. The aim of this study was to investigate the evolution of macroglial changes during retinal degeneration in P23H rats. Methods: Homozygous P23H line-3 rats aged from P18 to 18 months were used to study the evolution of the disease, and SD rats were used as controls. Immunolabeling with antibodies against GFAP, vimentin, and transducin were used to visualize macroglial cells and cone photoreceptors. Results: In P23H rats, increased GFAP labeling in Müller cells was observed as an early indicator of retinal gliosis. At 4 and 12 months of age, the apical processes of Müller cells in P23H rats clustered in firework-like structures, which were associated with ring-like shaped areas of cone degeneration in the outer nuclear layer. These structures were not observed at 16 months of age. The number of astrocytes was higher in P23H rats than in the SD matched controls at 4 and 12 months of age, supporting the idea of astrocyte proliferation. As the disease progressed, astrocytes exhibited a deteriorated morphology and marked hypertrophy. The increase in the complexity of the astrocytic processes correlated with greater connexin 43 expression and higher density of connexin 43 immunoreactive puncta within the ganglion cell layer (GCL) of P23H vs. SD rat retinas. Conclusions: In the P23H rat model of retinitis pigmentosa, the loss of photoreceptors triggers major changes in the number and morphology of glial cells affecting the inner retina. PMID:26733810

  3. Astrocytes and Müller cells changes during retinal degeneration in a transgenic rat model of retinitis pigmentosa.

    Directory of Open Access Journals (Sweden)

    Laura eFernández-Sánchez

    2015-12-01

    Full Text Available Purpose: Retinitis pigmentosa includes a group of progressive retinal degenerative diseases that affect the structure and function of photoreceptors. Secondarily to the loss of photoreceptors, there is a reduction in retinal vascularization, which seems to influence the cellular degenerative process. Retinal macroglial cells, astrocytes and Müller cells provide support for retinal neurons and are fundamental for maintaining normal retinal function. The aim of this study was to investigate the evolution of macroglial changes during retinal degeneration in P23H rats. Methods: Homozygous P23H line-3 rats aged from P18 to 18 months were used to study the evolution of the disease, and SD rats were used as controls. Immunolabeling with antibodies against GFAP, vimentin, and transducin were used to visualize macroglial cells and cone photoreceptors. Results: In P23H rats, increased GFAP labeling in Müller cells was observed as an early indicator of retinal gliosis. At 4 and 12 months of age, the apical processes of Müller cells in P23H rats clustered in firework-like structures, which were associated with ring-like shaped areas of cone degeneration in the outer nuclear layer. These structures were not observed at 16 months of age. The number of astrocytes was higher in P23H rats than in the SD matched controls at 4 and 12 months of age, supporting the idea of astrocyte proliferation. As the disease progressed, astrocytes exhibited a deteriorated morphology and marked hypertrophy. The increase in the complexity of the astrocytic processes correlated with greater connexin 43 expression and higher density of connexin 43 immunoreactive puncta within the ganglion cell layer of P23H versus SD rat retinas. Conclusions: In the P23H rat model of retinitis pigmentosa, the loss of photoreceptors triggers major changes in the number and morphology of glial cells affecting the inner retina.

  4. Transplantation of retinal pigment epithelial cells - a possible future treatment for age-related macular degeneration

    DEFF Research Database (Denmark)

    Wiencke, Anne Katrine

    2001-01-01

    ophthalmology, age-related macular degeneration, retinal pigment epithelial cells, transplantation, treatment......ophthalmology, age-related macular degeneration, retinal pigment epithelial cells, transplantation, treatment...

  5. Transplantation of retinal pigment epithelial cells - a possible future treatment for age-related macular degeneration

    DEFF Research Database (Denmark)

    Wiencke, Anne Katrine

    2001-01-01

    ophthalmology, age-related macular degeneration, transplantation, retinal pigment epithelial cells, treatment......ophthalmology, age-related macular degeneration, transplantation, retinal pigment epithelial cells, treatment...

  6. Age related macular degeneration and visual disability.

    Science.gov (United States)

    Christoforidis, John B; Tecce, Nicola; Dell'Omo, Roberto; Mastropasqua, Rodolfo; Verolino, Marco; Costagliola, Ciro

    2011-02-01

    Age-related macular degeneration (AMD) is the leading cause of central blindness or low vision among the elderly in industrialized countries. AMD is caused by a combination of genetic and environmental factors. Among modifiable environmental risk factors, cigarette smoking has been associated with both the dry and wet forms of AMD and may increase the likelihood of worsening pre-existing AMD. Despite advances, the treatment of AMD has limitations and affected patients are often referred for low vision rehabilitation to help them cope with their remaining eyesight. The characteristic visual impairment for both forms of AMD is loss of central vision (central scotoma). This loss results in severe difficulties with reading that may be only partly compensated by magnifying glasses or screen-projection devices. The loss of central vision associated with the disease has a profound impact on patient quality of life. With progressive central visual loss, patients lose their ability to perform the more complex activities of daily living. Common vision aids include low vision filters, magnifiers, telescopes and electronic aids. Low vision rehabilitation (LVR) is a new subspecialty emerging from the traditional fields of ophthalmology, optometry, occupational therapy, and sociology, with an ever-increasing impact on the usual concepts of research, education, and services for visually impaired patients. Relatively few ophthalmologists practise LVR and fewer still routinely use prismatic image relocation (IR) in AMD patients. IR is a method of stabilizing oculomotor functions with the purpose of promoting better function of preferred retinal loci (PRLs). The aim of vision rehabilitation therapy consists in the achievement of techniques designed to improve PRL usage. The use of PRLs to compensate for diseased foveae has offered hope to these patients in regaining some function. However, in a recently published meta-analysis, prism spectacles were found to be unlikely to be of

  7. Acquired Nonpigmented Vitreous Cyst Associated With Lattice Degeneration.

    Science.gov (United States)

    Lu, Jing; Mai, Guiying; Liu, Ruyuan; Luo, Yan; Lu, Lin

    2017-10-01

    A 63-year-old male presented with a round-shaped floater and visual obscuration in the right eye. Clinical evaluation showed a nonpigmented vitreous cyst connected to a lattice degeneration by a stalk. Immunostaining of the vitreous cyst obtained from vitrectomy showed its origin of retinal neuroepithelium. The cyst was formed by continuous vitreous traction, which might tear up the disrupted retina at the area of lattice degeneration. This report added the lattice degeneration to the list of causes for the acquired vitreous cyst. [Ophthalmic Surg Lasers Imaging Retina. 2017;48:856-858.]. Copyright 2017, SLACK Incorporated.

  8. [Clinical features and prognosis of retinal lattice degeneration].

    Science.gov (United States)

    Guo, X R

    1990-07-01

    110 cases (110 eyes) of retinal lattice degeneration were clinically observed and followed up for 3-8 years. Most lesions were located in the superotemporal quadrant, band-shaped, and parallel to the ora serrata. 80.9% of the lesions presented various degrees of pigmentation, 67.1% yellowish white spots, and 83.6% white lines. 32.9% of the eyes developed retinal holes. Most lattice degenerations were accompanied by vitreous degeneration and vitreoretinal traction. The disease progressed only slowly, though in a few cases it tended to expand.

  9. Animal models of disc degeneration and major genetic strategies.

    Science.gov (United States)

    Sun, Fu; Qu, Ji-Ning; Zhang, Yin-Gang

    2013-01-01

    The establishment of a reliable animal model of lumbar disc degeneration (AMDD) is important for studying pathogenesis and evaluating treatment effectiveness. However, an ideal AMDD for use in laboratory studies has not yet been produced. This retrospective study reviews and compares several common AMDD and discusses their strengths and weaknesses. We also suggest a new method for establishing future AMDD. The identified genes associated with disc degeneration are susceptibility genes, which elevate risk but do not necessarily lead to disease occurrence. We propose to identify families with hereditary disc degeneration, find major casual genes with exome sequencing, and establish transgenic animal models. This approach may help us to build an improved AMDD.

  10. Epidemiological Survey of Frontotemporal Lobar Degeneration in Tottori Prefecture, Japan

    Directory of Open Access Journals (Sweden)

    Kenji Wada-Isoe

    2012-09-01

    Full Text Available Background: The prevalence of frontotemporal lobar degeneration (FTLD in Japan is unknown. An epidemiological survey study of FTLD was undertaken in Tottori Prefecture, a district in the western region of Japan. Methods: Hospitals in Tottori Prefecture were surveyed by a two-step questionnaire in 2010, and the prevalence of FTLD per 100,000 inhabitants was calculated using the actual number of patients and inhabitants in Tottori Prefecture on the prevalence day of October 1, 2010. Results: In this survey, 66 patients were diagnosed with FTLD. The subtypes of FTLD were as follows: 62 cases of frontotemporal dementia (FTD, 3 cases of progressive nonfluent aphasia, and 1 case of semantic dementia. Among the FTD cases, 5 cases were FTD with motor neuron disease and 1 case was FTD with parkinsonism linked to chromosome 17. The prevalence of FTD in the total population of Tottori Prefecture was 11.2 per 100,000 inhabitants. Based on these results, the prevalence of FTLD in Japan in 2008 was estimated to be 9.5 per 100,000 individuals. Conclusions: Our epidemiological survey results suggest that there are at least 12,000 FTLD patients in Japan, indicating that FTLD is not a rare disease.

  11. Autoimmune neurological syndromes associated limbic encephalitis and paraneoplastic cerebellar degeneration.

    Science.gov (United States)

    Ayas, Zeynep Özözen; Kotan, Dilcan; Aras, Yeşim Güzey

    2016-10-06

    Autoimmune neurological syndrome is a group of disorders caused by cancer affecting nervous system by different immunological mechanisms. In this study, we aim to study the clinical symptoms, cerebrospinal fluid (CSF) findings, autoantibody tests, computed tomography (CT), magnetic resonance imaging (MRI) signs and treatment outcome of patients with autoimmune syndromes. In this study, 7 patients (4 male, 3 female) diagnosed with autoimmune neurological syndrome were retrospectively examined. Five of patients were diagnosed with limbic encephalitis, two of them were paraneoplastic cerebellar degeneration. Confusion and seizure were the most seen symptoms. Two patients had psychiatric disturbances (28,5%) followed by seizure. Headache was seen in 2 patients (% 28,5), disartria in 1 patient (% 14,2), and gait disorder in 2 patients (28,5%). The duration of symptoms was 46 (3-150) days on average. CSF abnormalities were detected in 2 patients. CT and MRI of the brain was available in all patients. Five patients had involvement of mesiotemporal region, two patients had diffuse cerebellar atrophy. One of patients had anti-GABAR B1 positivity. Tumors were detected in 2 patients while investigation for paraneoplasia screening. Remission is only possible with the detection and treatment of the malignancy. Early diagnosis and treatment are of paramount importance. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  12. Pathogenesis of progressive rod-cone degeneration in miniature poodles

    Energy Technology Data Exchange (ETDEWEB)

    Aguirre, G.; Alligood, J.; O' Brien, P.; Buyukmihci, N.

    1982-11-01

    Visual cell pathologic changes and outer segment renewal were investigated in miniature poodles with progressive rod-cone degeneration. Early in this disease, visual cells in the posterior pole and equatorial regions show outer segment lamellar disorientation and vesicular profiles. Visual cells are normal in the periphery. Outer segment renewal determined after intravitreal injection of /sup 3/H-leucine was abnormally slower in affected animals than in controls. This renewal abnormality was similar in structurally normal and diseased photoreceptors, suggesting that the renewal defect is the earliest recognizable abnormality in the disease. The pigment epithelium was normal; the presence and density of pigment did not appear to affect the extent and severity of the disease or modify the abnormal renewal rate. As the disease progressed, photoreceptor outer segments were lost, and the remaining diminutive photoreceptors accumulated label in the inner segment and perinuclear zones. Sodium dodecyl sulfate gel electrophoresis of crude rod outer segment preparations showed no differences in opsin synthesis between normal and affected retinas early in the disease, but opsin synthesis decreased in the late stage of the disease.

  13. Single-cell resolution imaging of retinal ganglion cell apoptosis in vivo using a cell-penetrating caspase-activatable peptide probe.

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    Xudong Qiu

    Full Text Available Peptide probes for imaging retinal ganglion cell (RGC apoptosis consist of a cell-penetrating peptide targeting moiety and a fluorophore-quencher pair flanking an effector caspase consensus sequence. Using ex vivo fluorescence imaging, we previously validated the capacity of these probes to identify apoptotic RGCs in cell culture and in an in vivo rat model of N-methyl- D-aspartate (NMDA-induced neurotoxicity. Herein, using TcapQ488, a new probe designed and synthesized for compatibility with clinically-relevant imaging instruments, and real time imaging of a live rat RGC degeneration model, we fully characterized time- and dose-dependent probe activation, signal-to-noise ratios, and probe safety profiles in vivo. Adult rats received intravitreal injections of four NMDA concentrations followed by varying TcapQ488 doses. Fluorescence fundus imaging was performed sequentially in vivo using a confocal scanning laser ophthalmoscope and individual RGCs displaying activated probe were counted and analyzed. Rats also underwent electroretinography following intravitreal injection of probe. In vivo fluorescence fundus imaging revealed distinct single-cell probe activation as an indicator of RGC apoptosis induced by intravitreal NMDA injection that corresponded to the identical cells observed in retinal flat mounts of the same eye. Peak activation of probe in vivo was detected 12 hours post probe injection. Detectable fluorescent RGCs increased with increasing NMDA concentration; sensitivity of detection generally increased with increasing TcapQ488 dose until saturating at 0.387 nmol. Electroretinography following intravitreal injections of TcapQ488 showed no significant difference compared with control injections. We optimized the signal-to-noise ratio of a caspase-activatable cell penetrating peptide probe for quantitative non-invasive detection of RGC apoptosis in vivo. Full characterization of probe performance in this setting creates an important in

  14. Antidepressant Imipramine Protects Bupivacaine-Induced Neurotoxicity in Dorsal Root Ganglion Neurons Through Coactivation of TrkA and TrkB.

    Science.gov (United States)

    Guo, Jianrong; Wang, Huan; Tao, Qiang; Sun, Shiyu; Liu, Li; Zhang, Jianping; Yang, Dawei

    2017-11-01

    In our work, we used an in vitro culture model to investigate whether antidepressant imipramine (Ip) may protect bupivacaine (Bv)-induced neurotoxicity in mouse dorsal root ganglion (DRG). Adult mouse DRG was treated with 5 mM Bv in vitro to induce neurotoxicity. DRG was then pre-treated with Ip, prior to Bv, to examine its effects on protecting Bv-induced DRG apoptosis and neurite degeneration. Ip-induced dynamic changes in Trk receptors, including TrkA/B/C and phosphor (p-)TrkA/B/C, were examined by qPCR and Western blot. TrkA and TrkB were inhibited by siRNAs to further investigate their functional role in Ip- and Bv-treated DRG. Ip protected Bv-induced apoptosis and neurite loss in DRG. Ip did not alter TrkA/B/C expressions, whereas significantly augmented protein productions of p-TrkA and p-TrkB, but not p-TrkC. SiRNA-mediated TrkA or TrkB downregulation inhibited Trk receptors, and reduced p-TrkA and p-TrkB in DRG. TrkA or TrkB downregulation alone had no effect on Ip-induced protection in Bv-injured DRG. However, co-inhibition of TrkA and TrkB significantly ameliorated the protective effect of Ip on Bv-induced apoptosis and neurite loss in DRG. Imipramine protected bupivacaine-induced neurotoxicity in DRG, likely via the co-activation of TrkA and TrkB signaling pathways. J. Cell. Biochem. 118: 3960-3967, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  15. On degenerate metrics, dark matter and unification

    Science.gov (United States)

    Searight, Trevor P.

    2017-12-01

    A five-dimensional theory of relativity is presented which suggests that gravitation and electromagnetism may be unified using a degenerate metric. There are four fields (in the four-dimensional sense): a tensor field, two vector fields, and a scalar field, and they are unified with a combination of a gauge-like invariance and a reflection symmetry which means that both vector fields are photons. The gauge-like invariance implies that the fifth dimension is not directly observable; it also implies that charge is a constant of motion. The scalar field is analogous to the Brans-Dicke scalar field, and the theory tends towards the Einstein-Maxwell theory in the limit as the coupling constant tends to infinity. As there is some scope for fields to vary in the fifth dimension, it is possible for the photons to have wave behaviour in the fifth dimension. The wave behaviour has two effects: it gives mass to the photons, and it prevents them from interacting directly with normal matter. These massive photons still act as a source of gravity, however, and therefore they are candidates for dark matter.

  16. CERKL knockdown causes retinal degeneration in zebrafish.

    Directory of Open Access Journals (Sweden)

    Marina Riera

    Full Text Available The human CERKL gene is responsible for common and severe forms of retinal dystrophies. Despite intense in vitro studies at the molecular and cellular level and in vivo analyses of the retina of murine knockout models, CERKL function remains unknown. In this study, we aimed to approach the developmental and functional features of cerkl in Danio rerio within an Evo-Devo framework. We show that gene expression increases from early developmental stages until the formation of the retina in the optic cup. Unlike the high mRNA-CERKL isoform multiplicity shown in mammals, the moderate transcriptional complexity in fish facilitates phenotypic studies derived from gene silencing. Moreover, of relevance to pathogenicity, teleost CERKL shares the two main human protein isoforms. Morpholino injection has been used to generate a cerkl knockdown zebrafish model. The morphant phenotype results in abnormal eye development with lamination defects, failure to develop photoreceptor outer segments, increased apoptosis of retinal cells and small eyes. Our data support that zebrafish Cerkl does not interfere with proliferation and neural differentiation during early developmental stages but is relevant for survival and protection of the retinal tissue. Overall, we propose that this zebrafish model is a powerful tool to unveil CERKL contribution to human retinal degeneration.

  17. Correlations in a partially degenerate electron plasma

    Energy Technology Data Exchange (ETDEWEB)

    Chihara, Junzo [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1998-03-01

    The density-functional theory proves that an ion-electron mixture can be treated as a one-component liquid interacting only via a pairwise interaction in the evaluation of the ion-ion radial distribution function (RDF), and provides a set of integral equations: one is an integral equation for the ion-ion RDF and another for an effective ion-ion interaction, which depends on the ion-ion RDF. This formulation gives a set of integral equation to calculate plasma structures with combined use of the electron-electron correlations in a partially degenerate electron plasma. Therefore, it is important for this purpose to determine the electron-electron correlations at a arbitrary temperature. Here, they are calculated by the quantal version of the hypernetted chain (HNC) equation. On the basis of the jellium-vacancy model, the ionic and electronic structures of rubidium are calculated for the range from liquid metal to plasma states by increasing the temperature at the fixed density using the electron-correlation results. (author)

  18. Linear stochastic degenerate Sobolev equations and applications†

    Science.gov (United States)

    Liaskos, Konstantinos B.; Pantelous, Athanasios A.; Stratis, Ioannis G.

    2015-12-01

    In this paper, a general class of linear stochastic degenerate Sobolev equations with additive noise is considered. This class of systems is the infinite-dimensional analogue of linear descriptor systems in finite dimensions. Under appropriate assumptions, the mild and strong well-posedness for the initial value problem are studied using elements of the semigroup theory and properties of the stochastic convolution. The final value problem is also examined and it is proved that this is uniquely strongly solvable and the solution is continuously dependent on the final data. Based on the results of the forward and backward problem, the conditions for the exact controllability are investigated for a special but important class of these equations. The abstract results are illustrated by applications in complex media electromagnetics, in the one-dimensional stochastic Dirac equation in the non-relativistic limit and in a potential application in input-output analysis in economics. Dedicated to Professor Grigoris Kalogeropoulos on the occasion of his seventieth birthday.

  19. Radiotherapy in age-related macula degeneration

    International Nuclear Information System (INIS)

    Gripp, Stephan; Stammen, Johannes; Petersen, Claudia; Hartmann, Axel; Willers, Reinhart; Althaus, Christoph

    2002-01-01

    Purpose: To ascertain the benefit from radiotherapy in age-related macula degeneration in a single-arm longitudinal study. Methods and Materials: From 1997 to 1998, 39 patients with occult and 33 patients with classic choroidal neovascularization (CNV) were irradiated with 16 Gy. Fluorescein angiography and measurements of visual acuity were performed before and 3, 6, and 12 months after irradiation. Results: Complete follow-up data for 1 year were available from 69 patients. The mean patient age was 72 years (range 49-92). Vision decreased in 43, was stable in 18, and improved in 8 cases. The mean vision deteriorated significantly (p=0.02, Wilcoxon test), particularly within the first 3 months. Patients with occult CNV did significantly better than did those with classic CNV (p=0.03). The proportion of patients retaining vision ≥0.2 fell from 65% to 42% (p <0.01), for classic and occult CNV from 50% to 23%, and for occult CNV from 77% to 56% (p<0.02), respectively. CNV size increased in 30 patients and was stable in 38. Neither age (p=0.17) nor gender (p=0.21, chi-square test) influenced prognosis. Four patients reported transitional complaints. Conclusion: Low-dose fractionated radiotherapy with 16 Gy is well tolerated. However, vision and reading ability were not preserved in most patients

  20. Animal models of age related macular degeneration

    Science.gov (United States)

    Pennesi, Mark E.; Neuringer, Martha; Courtney, Robert J.

    2013-01-01

    Age related macular degeneration (AMD) is the leading cause of vision loss of those over the age of 65 in the industrialized world. The prevalence and need to develop effective treatments for AMD has lead to the development of multiple animal models. AMD is a complex and heterogeneous disease that involves the interaction of both genetic and environmental factors with the unique anatomy of the human macula. Models in mice, rats, rabbits, pigs and non-human primates have recreated many of the histological features of AMD and provided much insight into the underlying pathological mechanisms of this disease. In spite of the large number of models developed, no one model yet recapitulates all of the features of human AMD. However, these models have helped reveal the roles of chronic oxidative damage, inflammation and immune dysregulation, and lipid metabolism in the development of AMD. Models for induced choroidal neovascularization have served as the backbone for testing new therapies. This article will review the diversity of animal models that exist for AMD as well as their strengths and limitations. PMID:22705444