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Sample records for cortico-basal ganglionic degeneration

  1. The metabolic landscape of cortico-basal ganglionic degeneration: regional asymmetries studied with positron emission tomography.

    PubMed Central

    Eidelberg, D; Dhawan, V; Moeller, J R; Sidtis, J J; Ginos, J Z; Strother, S C; Cederbaum, J; Greene, P; Fahn, S; Powers, J M

    1991-01-01

    Regional metabolic rate for glucose (rCMRGlc) was estimated using [18F]fluorodeoxyglucose (FDG) and positron emission tomography (PET) in five patients (four men, one woman; mean age 68; mean disease duration 2.4 years) with clinical findings consistent with the syndrome of cortico-basal ganglionic degeneration (CBGD). Left-right rCMRGlc asymmetry, (L-R)/(L + R) x 100, was calculated for 13 grey matter regions and compared with regional metabolic data from 18 normal volunteers and nine patients with asymmetrical Parkinson's disease (PD). In the CBGD group mean metabolic asymmetry values in the thalamus, inferior parietal lobule and hippocampus were greater than those measured in normal control subjects and patients with asymmetrical PD (p less than 0.02). Parietal lobe asymmetry of 5% or more was evident in all CBGD patients, whereas in PD patients and normal controls, all regional asymmetry measures were less than 5% in absolute value. Measures of frontal, parietal and hemispheric metabolic asymmetry were found to be positively correlated with asymmetries in thalamic rCMRGlc (p less than 0.05). The presence of cortico-thalamic metabolic asymmetry is consistent with the focal neuropathological changes reported in CBGD brains. Our findings suggest that metabolic asymmetries detected with FDG/PET may support a diagnosis of CBGD in life. Images PMID:1744638

  2. Transcranial Magnetic Stimulation (TMS) as a Tool for Early Diagnosis and Prognostication in Cortico-Basal Ganglia Degeneration (CBD) Syndromes: Review of Literature and Case Report

    PubMed Central

    Issac, Thomas Gregor; Chandra, Sadanandavalli Retnaswami; Nagaraju, B. C.

    2016-01-01

    Background: Cortico basal degeneration (CBD) of the brain is a rare progressive neurodegenerative disease which encompasses unique neuropsychiatric manifestations. Early diagnosis is essential for initiating proper treatment and favorable outcome. Transcranial Magnetic Stimulation (TMS), a well-known technique for assessment of cortical excitatory and inhibitory properties. It was suggested that in a degenerative disease like CBD which involves the cortex as well as the subcortical structures, comparing both hemispheres, a differential pattern in TMS can be obtained which would help in early identification, prognostication and early therapeutic intervention. Case Report: We describe a case of CBD with corroborative clinical and imaging picture wherein single pulse TMS was used over both the hemispheres measuring the following parameters of interest which included: Motor Threshold (MT), Central Motor Conduction Time (CMCT) and Silent Period (SP). Results and Conclusion: Differential patterns of MT, CMCT and SP was obtained by stimulating over both the hemispheres with the affected hemisphere showing significantly reduced MT and prolonged CMCT implying early impairment of cortical and subcortical structures thereby revealing the potential application of TMS being utilized in a novel way for early detection and prognostication in CBD syndromes. PMID:27011412

  3. Cortical basal ganglionic degeneration.

    PubMed

    Scarmeas, N; Chin, S S; Marder, K

    2001-10-01

    In this case study, we describe the symptoms, neuropsychological testing, and brain pathology of a retired mason's assistant with cortical basal ganglionic degeneration (CBGD). CBGD is an extremely rare neurodegenerative disease that is categorized under both Parkinsonian syndromes and frontal lobe dementias. It affects men and women nearly equally, and the age of onset is usually in the sixth decade of life. CBGD is characterized by Parkinson's-like motor symptoms and by deficits of movement and cognition, indicating focal brain pathology. Neuronal cell loss is ultimately responsible for the neurological symptoms. PMID:14602941

  4. Neural representation of time in cortico-basal ganglia circuits

    PubMed Central

    Jin, Dezhe Z.; Fujii, Naotaka; Graybiel, Ann M.

    2009-01-01

    Encoding time is universally required for learning and structuring motor and cognitive actions, but how the brain keeps track of time is still not understood. We searched for time representations in cortico-basal ganglia circuits by recording from thousands of neurons in the prefrontal cortex and striatum of macaque monkeys performing a routine visuomotor task. We found that a subset of neurons exhibited time-stamp encoding strikingly similar to that required by models of reinforcement-based learning: They responded with spike activity peaks that were distributed at different time delays after single task events. Moreover, the temporal evolution of the population activity allowed robust decoding of task time by perceptron models. We suggest that time information can emerge as a byproduct of event coding in cortico-basal ganglia circuits and can serve as a critical infrastructure for behavioral learning and performance. PMID:19850874

  5. [Parkinson's disease and cortico-Basal Ganglia circuits].

    PubMed

    Pan, Ming-Kai; Tai, Chun-Hwei; Kuo, Chung-Chin

    2010-09-01

    Cortico-basal ganglia circuit model has been studied extensively after it was first proposed by Alexander and Crutcher in 1990. This model accurately predicted the hyperactivity of indirect pathway and subthalamic nucleus(STN) in the dopamine deficiency state of Parkinson's disease (PD), prompting the experimental approaches of lesioning STN in parkinsonian primates. Application of these successful experiences with STN lesions in the reversal of parkinsonian symptoms to human PD patients facilitates the development of STN deep brain stimulation (DBS), which has become one of the most important therapies for PD in recent years. Although the classical model of the cortico-basal ganglia circuits by Alexander and Crutcher has provided many important insights into the basal ganglia function, the functional role of cortico-subthalamic "hyperdirect" pathway in the circuits has been relatively neglected. The first part of this article summarizes recent development concerning the cortico-basal ganglia circuits, especially emphasizing the importance of the hyperdirect pathway. In the second part of this article, we would describe the analyses of gross corticobasal ganglia circuit electrophysiological findings, especially emphasizing the coherence between two oscillating signals. We would also discuss the correlation between these parameters and the motor dysfunction, and its pathophysiological implications in PD. PMID:20824544

  6. Cortico-Basal Ganglia Circuit Function in Psychiatric Disease.

    PubMed

    Gunaydin, Lisa A; Kreitzer, Anatol C

    2016-01-01

    Circuit dysfunction models of psychiatric disease posit that pathological behavior results from abnormal patterns of electrical activity in specific cells and circuits in the brain. Many psychiatric disorders are associated with abnormal activity in the prefrontal cortex and in the basal ganglia, a set of subcortical nuclei implicated in cognitive and motor control. Here we discuss the role of the basal ganglia and connected prefrontal regions in the etiology and treatment of obsessive-compulsive disorder, anxiety, and depression, emphasizing mechanistic work in rodent behavioral models to dissect causal cortico-basal ganglia circuits underlying discrete behavioral symptom domains relevant to these complex disorders. PMID:26667072

  7. Changes in ganglion cells during retinal degeneration.

    PubMed

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

    2016-08-01

    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. PMID:27132232

  8. Degeneration and regeneration of ganglion cell axons.

    PubMed

    Weise, J; Ankerhold, R; Bähr, M

    2000-01-15

    The retino-tectal system has been used to study developmental aspects of axon growth, synapse formation and the establishment of a precise topographic order as well as degeneration and regeneration of adult retinal ganglion cell (RGC) axons after axonal lesion. This paper reviews some novel findings that provide new insights into the mechanisms of developmental RGC axon growth, pathfinding, and target formation. It also focuses on the cellular and molecular cascades that underlie RGC degeneration following an axonal lesion and on some therapeutic strategies to enhance survival of axotomized RGCs in vivo. In addition, this review deals with problems related to the induction of regeneration after axonal lesion in the adult CNS using the retino-tectal system as model. Different therapeutic approaches to promote RGC regeneration and requirements for specific target formation of regenerating RGCs in vitro and in vivo are discussed. PMID:10649506

  9. Coupling in the cortico-basal ganglia circuit is aberrant in the ketamine model of schizophrenia.

    PubMed

    Cordon, Ivan; Nicolás, María Jesús; Arrieta, Sandra; Lopetegui, Eneko; López-Azcárate, Jon; Alegre, Manuel; Artieda, Julio; Valencia, Miguel

    2015-08-01

    Recent studies have suggested the implication of the basal ganglia in the pathogenesis of schizophrenia. To investigate this hypothesis, here we have used the ketamine model of schizophrenia to determine the oscillatory abnormalities induced in the rat motor circuit of the basal ganglia. The activity of free moving rats was recorded in different structures of the cortico-basal ganglia circuit before and after an injection of a subanesthesic dose of ketamine (10mg/kg). Spectral estimates of the oscillatory activity, phase-amplitude cross-frequency coupling interactions (CFC) and imaginary event-related coherence together with animals׳ behavior were analyzed. Oscillatory patterns in the cortico-basal ganglia circuit were highly altered by the effect of ketamine. CFC between the phases of low-frequency activities (delta, 1-4; theta 4-8Hz) and the amplitude of high-gamma (~80Hz) and high-frequency oscillations (HFO) (~150Hz) increased dramatically and correlated with the movement increment shown by the animals. Between-structure analyses revealed that ketamine had also a massive effect in the low-frequency mediated synchronization of the HFO's across the whole circuit. Our findings suggest that ketamine administration results in an aberrant hypersynchronization of the whole cortico-basal circuit where the tandem theta/HFO seems to act as the main actor in the hyperlocomotion shown by the animals. Here we stress the importance of the basal ganglia circuitry in the ketamine model of schizophrenia and leave the door open to further investigations devoted to elucidate to what extent these abnormalities also reflect the prominent neurophysiological deficits observed in schizophrenic patients. PMID:25910422

  10. Identifying enhanced cortico-basal ganglia loops associated with prolonged dance training.

    PubMed

    Li, Gujing; He, Hui; Huang, Mengting; Zhang, Xingxing; Lu, Jing; Lai, Yongxiu; Luo, Cheng; Yao, Dezhong

    2015-01-01

    Studies have revealed that prolonged, specialized training combined with higher cognitive conditioning induces enhanced brain alternation. In particular, dancers with long-term dance experience exhibit superior motor control and integration with their sensorimotor networks. However, little is known about the functional connectivity patterns of spontaneous intrinsic activities in the sensorimotor network of dancers. Our study examined the functional connectivity density (FCD) of dancers with a mean period of over 10 years of dance training in contrast with a matched non-dancer group without formal dance training using resting-state fMRI scans. FCD was mapped and analyzed, and the functional connectivity (FC) analyses were then performed based on the difference of FCD. Compared to the non-dancers, the dancers exhibited significantly increased FCD in the precentral gyri, postcentral gyri and bilateral putamen. Furthermore, the results of the FC analysis revealed enhanced connections between the middle cingulate cortex and the bilateral putamen and between the precentral and the postcentral gyri. All findings indicated an enhanced functional integration in the cortico-basal ganglia loops that govern motor control and integration in dancers. These findings might reflect improved sensorimotor function for the dancers consequent to long-term dance training. PMID:26035693

  11. Identifying enhanced cortico-basal ganglia loops associated with prolonged dance training

    PubMed Central

    Li, Gujing; He, Hui; Huang, Mengting; Zhang, Xingxing; Lu, Jing; Lai, Yongxiu; Luo, Cheng; Yao, Dezhong

    2015-01-01

    Studies have revealed that prolonged, specialized training combined with higher cognitive conditioning induces enhanced brain alternation. In particular, dancers with long-term dance experience exhibit superior motor control and integration with their sensorimotor networks. However, little is known about the functional connectivity patterns of spontaneous intrinsic activities in the sensorimotor network of dancers. Our study examined the functional connectivity density (FCD) of dancers with a mean period of over 10 years of dance training in contrast with a matched non-dancer group without formal dance training using resting-state fMRI scans. FCD was mapped and analyzed, and the functional connectivity (FC) analyses were then performed based on the difference of FCD. Compared to the non-dancers, the dancers exhibited significantly increased FCD in the precentral gyri, postcentral gyri and bilateral putamen. Furthermore, the results of the FC analysis revealed enhanced connections between the middle cingulate cortex and the bilateral putamen and between the precentral and the postcentral gyri. All findings indicated an enhanced functional integration in the cortico-basal ganglia loops that govern motor control and integration in dancers. These findings might reflect improved sensorimotor function for the dancers consequent to long-term dance training. PMID:26035693

  12. Cortico-basal ganglia circuits involved in different motivation disorders in non-human primates.

    PubMed

    Sgambato-Faure, Véronique; Worbe, Yulia; Epinat, Justine; Féger, Jean; Tremblay, Léon

    2016-01-01

    The ventral striatum (VS) is of particular interest in the study of neuropsychiatric disorders. In this study, performed on non-human primates, we associated local perturbation with monosynaptic axonal tracer injection into medial, central and lateral VS to characterize anatomo-functional circuits underlying the respective expression of sexual manifestations, stereotyped behaviors and hypoactive state associated with loss of food motivation. For the three behavioral effects, we demonstrated the existence of three distinct cortico-basal ganglia (BG) circuits that were topographically organized and overlapping at some cortical (orbitofrontal cortex, anterior cingulate cortex) and subcortical (caudal levels of BG) levels, suggesting interactions between motivation domains. Briefly, erection was associated with a circuit involving the orbitofrontal cortex, medial prefrontal cortex (areas 10, 11) and limbic parts of BG, i.e. medial parts of the pallidal complex and the substantia nigra pars reticulata (SNr). Stereotyped behavior was linked to a circuit involving the lateral orbitofrontal cortex (area 12/47) and limbic parts of the pallidal complex and of the SNr, while the apathetic state was underlined by a circuit involving not only the orbital and medial prefrontal cortex but also the lateral prefrontal cortex (area 8, 45), the anterior insula and the lateral parts of the medial pallidal complex and of the ventro-medial SNr. For the three behavioral effects, the cortico-BG circuits mainly involved limbic regions of the external and internal pallidum, as well as the limbic part of the substantia nigra pars reticulata (SNr), suggesting the involvement of both direct and indirect striatal pathways and both output BG structures. As these motivation disorders could still be induced in dopamine (DA)-depleted monkeys, we suggest that DA issued from the substantia nigra pars compacta (SNc) modulates their expression rather than causes them. Finally, this study may give some

  13. Taurine provides neuroprotection against retinal ganglion cell degeneration.

    PubMed

    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

  14. Taurine Provides Neuroprotection against Retinal Ganglion Cell Degeneration

    PubMed Central

    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

  15. Degeneration of retinal ganglion cells in diabetic dogs and mice: Relationship to glycemic control and retinal capillary degeneration

    PubMed Central

    Howell, Scott J.; Mekhail, Mena N.; Azem, Rami; Ward, Nicole L.

    2013-01-01

    Purpose The purpose of this study was to investigate (i) the effect of diabetes on retinal ganglion cell death in diabetic dogs and mice, (ii) the effect of prolonged glycemic control on diabetes-induced death of retinal ganglion cells, (iii) whether retinal ganglion cell death in diabetes is associated with degeneration of retinal capillaries, and (iv) the effect of diet on diabetes-induced degeneration of retinal ganglion cells in mice. Methods Diabetes was induced in dogs using streptozotocin, and levels of glycemic control (good, moderate, and poor) were maintained for 5 years. Diabetes was studied in two mouse models (diabetes induced in C57Bl/6J mice using streptozotocin and spontaneously diabetic Ins2Akita mice). Retinal ganglion cell death was investigated by counting the number of axons from the ganglion cells in the optic nerve and with terminal transferase deoxyuridine triphosphate nick-end labeling and annexin V staining in mice. Results As reported previously, the development and severity of vascular lesions of diabetic retinopathy in diabetic dogs were strongly associated with glycemic control. Loss of retinal ganglion cells was extensive in dogs kept in poor glycemic control, and was essentially prevented in diabetic dogs kept in good glycemic control for the 5 years of study. In contrast, “moderate” glycemic control (intermediate between poor and good glycemic control) caused a significant increase in vascular pathology, but did not cause loss of retinal axons in the optic nerve. Using this validated optic nerve axon counting method, the two mouse models of diabetic retinopathy were studied to assess ganglion cell death. Despite 10 months of diabetes (a duration that has been shown to cause retinal capillary degeneration in both models), neither mouse model showed loss of optic nerve axons (thus suggesting no loss of retinal ganglion cells). Likewise, other parameters of cell death (terminal transferase deoxyuridine triphosphate nick

  16. Changes in morphology of retinal ganglion cells with eccentricity in retinal degeneration.

    PubMed

    Anderson, E E; Greferath, U; Fletcher, E L

    2016-05-01

    Ganglion cells are the output neurons of the retina and are known to remodel during the subtle plasticity changes that occur following the death of photoreceptors in inherited retinal degeneration. We examine the influence of retinal eccentricity on anatomical remodelling and ganglion cell morphology well after photoreceptor loss. Rd1 mice that have a mutation in the β subunit of phosphodiesterase 6 were used as a model of retinal degeneration and gross remodelling events were examined by processing serial sections for immunocytochemistry. Retinal wholemounts from rd1-Thy1 and control Thy1 mice that contained a fluorescent protein labelling a subset of ganglion cells were processed for immunohistochemistry at 11 months of age. Ganglion cells were classified based on their soma size, dendritic field size and dendritic branching pattern and their dendritic fields were analysed for their length, area and quantity of branching points. Overall, more remodelling was found in the central compared with the peripheral retina. In addition, the size and complexity of A2, B1, C1 and D type ganglion cells located in the central region of the retina decreased. We propose that the changes in ganglion cell morphology are correlated with remodelling events in these regions and impact the function of retinal circuitry in the degenerated retina. PMID:26670589

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

    NASA Astrophysics Data System (ADS)

    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.

  18. Tractographical model of the cortico-basal ganglia and corticothalamic connections: Improving Our Understanding of Deep Brain Stimulation.

    PubMed

    Avecillas-Chasin, Josué M; Rascón-Ramírez, Fernando; Barcia, Juan A

    2016-05-01

    The cortico-basal ganglia and corticothalamic projections have been extensively studied in the context of neurological and psychiatric disorders. Deep brain stimulation (DBS) is known to modulate many of these pathways to produce the desired clinical effect. The aim of this work is to describe the anatomy of the main circuits of the basal ganglia using tractography in a surgical planning station. We used imaging studies of 20 patients who underwent DBS for movement and psychiatric disorders. We segmented the putamen, caudate nucleus (CN), thalamus, and subthalamic nucleus (STN), and we also segmented the cortical areas connected with these subcortical areas. We used tractography to define the subdivisions of the basal ganglia and thalamus through the generation of fibers from the cortical areas to the subcortical structures. We were able to generate the corticostriatal and corticothalamic connections involved in the motor, associative and limbic circuits. Furthermore, we were able to reconstruct the hyperdirect pathway through the corticosubthalamic connections and we found subregions in the STN. Finally, we reconstructed the cortico-subcortical connections of the ventral intermediate nucleus, the nucleus accumbens and the CN. We identified a feasible delineation of the basal ganglia and thalamus connections using tractography. These results could be potentially useful in DBS if the parcellations are used as targets during surgery. Clin. Anat. 29:481-492, 2016. © 2016 Wiley Periodicals, Inc. PMID:26779936

  19. Neuroprotective Effect of Tauroursodeoxycholic Acid on N-Methyl-D-Aspartate-Induced Retinal Ganglion Cell Degeneration

    PubMed Central

    Fernández-Sánchez, Laura; Rondón, Netxibeth; Esquiva, Gema; Germain, Francisco; de la Villa, Pedro; Cuenca, Nicolás

    2015-01-01

    Retinal ganglion cell degeneration underlies the pathophysiology of diseases affecting the retina and optic nerve. Several studies have previously evidenced the anti-apoptotic properties of the bile constituent, tauroursodeoxycholic acid, in diverse models of photoreceptor degeneration. The aim of this study was to investigate the effects of systemic administration of tauroursodeoxycholic acid on N-methyl-D-aspartate (NMDA)-induced damage in the rat retina using a functional and morphological approach. Tauroursodeoxycholic acid was administered intraperitoneally before and after intravitreal injection of NMDA. Three days after insult, full-field electroretinograms showed reductions in the amplitudes of the positive and negative-scotopic threshold responses, scotopic a- and b-waves and oscillatory potentials. Quantitative morphological evaluation of whole-mount retinas demonstrated a reduction in the density of retinal ganglion cells. Systemic administration of tauroursodeoxycholic acid attenuated the functional impairment induced by NMDA, which correlated with a higher retinal ganglion cell density. Our findings sustain the efficacy of tauroursodeoxycholic acid administration in vivo, suggesting it would be a good candidate for the pharmacological treatment of degenerative diseases coursing with retinal ganglion cell loss. PMID:26379056

  20. Retrograde and Wallerian Axonal Degeneration Occur Synchronously after Retinal Ganglion Cell Axotomy

    PubMed Central

    Kanamori, Akiyasu; Catrinescu, Maria-Magdalena; Belisle, Jonathan M.; Costantino, Santiago; Levin, Leonard A.

    2013-01-01

    Axonal injury and degeneration are pivotal pathological events in diseases of the nervous system. In the past decade, it has been recognized that the process of axonal degeneration is distinct from somal degeneration and that axoprotective strategies may be distinct from those that protect the soma. Preserving the cell body via neuroprotection cannot improve function if the axon is damaged, because the soma is still disconnected from its target. Therefore, understanding the mechanisms of axonal degeneration is critical for developing new therapeutic interventions for axonal disease treatment. We combined in vivo imaging with a multilaser confocal scanning laser ophthalmoscope and in vivo axotomy with a diode-pumped solid-state laser to assess the time course of Wallerian and retrograde degeneration of unmyelinated retinal ganglion cell axons in living rats for 4 weeks after intraretinal axotomy. Laser injury resulted in reproducible axon loss both distal and proximal to the site of injury. Longitudinal polarization-sensitive imaging of axons demonstrated that Wallerian and retrograde degeneration occurred synchronously. Neurofilament immunostaining of retinal whole-mounts confirmed axonal loss and demonstrated sparing of adjacent axons to the axotomy site. In vivo fluorescent imaging of axonal transport and photobleaching of labeled axons demonstrated that the laser axotomy model did not affect adjacent axon function. These results are consistent with a shared mechanism for Wallerian and retrograde degeneration. PMID:22642911

  1. Time-Lapse Retinal Ganglion Cell Dendritic Field Degeneration Imaged in Organotypic Retinal Explant Culture

    PubMed Central

    Johnson, Thomas V.; Oglesby, Ericka N.; Steinhart, Matthew R.; Cone-Kimball, Elizabeth; Jefferys, Joan; Quigley, Harry A.

    2016-01-01

    Purpose To develop an ex vivo organotypic retinal explant culture system suitable for multiple time-point imaging of retinal ganglion cell (RGC) dendritic arbors over a period of 1 week, and capable of detecting dendrite neuroprotection conferred by experimental treatments. Methods Thy1-YFP mouse retinas were explanted and maintained in organotypic culture. Retinal ganglion cell dendritic arbors were imaged repeatedly using confocal laser scanning microscopy. Maximal projection z-stacks were traced by two masked investigators and dendritic fields were analyzed for characteristics including branch number, size, and complexity. One group of explants was treated with brain derived neurotrophic factor (BDNF) and ciliary neurotrophic factor (CNTF) added to the culture media. Changes in individual dendritic fields over time were detected using pair-wise comparison testing. Results Retinal ganglion cells in mouse retinal explant culture began to degenerate after 3 days with 52.4% surviving at 7 days. Dendritic field parameters showed minimal change over 8 hours in culture. Intra- and interobserver measurements of dendrite characteristics were strongly correlated (Spearman rank correlations consistently > 0.80). Statistically significant (P < 0.001) dendritic tree degeneration was detected following 7 days in culture including: 40% to 50% decreases in number of branch segments, number of junctions, number of terminal branches, and total branch length. Scholl analyses similarly demonstrated a significant decrease in dendritic field complexity. Treatment of explants with BDNF+CNTF significantly attenuated dendritic field degeneration. Conclusions Retinal explant culture of Thy1-YFP tissue provides a useful model for time-lapse imaging of RGC dendritic field degeneration over a course of several days, and is capable of detecting neuroprotective amelioration of dendritic pruning within individual RGCs. PMID:26811145

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

    PubMed

    de Lima, S; Mietto, B S; Paula, C; Muniz, T; Martinez, A M B; Gardino, P F

    2016-01-01

    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. PMID:27007653

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

    PubMed Central

    de Lima, S.; Mietto, B.S.; Paula, C.; Muniz, T.; Martinez, A.M.B.; Gardino, P.F.

    2016-01-01

    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. PMID:27007653

  4. Homonymous Ganglion Cell Layer Thinning After Isolated Occipital Lesion: Macular OCT Demonstrates Transsynaptic Retrograde Retinal Degeneration.

    PubMed

    Meier, Paolo G; Maeder, Philippe; Kardon, Randy H; Borruat, François-Xavier

    2015-06-01

    A 48-year-old man was examined 24 months after medial and surgical treatment of an isolated well-circumscribed right occipital lobe abscess. An asymptomatic residual left homonymous inferior scotoma was present. Fundus examination revealed temporal pallor of both optic discs, and optical coherence tomography (OCT) revealed mild temporal loss of retinal nerve fiber layer in both eyes. No relative afferent pupillary defect was present. Assessment of the retinal ganglion cell layer demonstrated homonymous thinning in a pattern corresponding to the homonymous visual field loss. There were no abnormalities of the lateral geniculate nuclei or optic tracts on review of the initial brain computed tomography and follow-up magnetic resonance imaging. We believe our patient showed evidence of transsynaptic retrograde degeneration after an isolated right occipital lobe lesion, and the homonymous neuronal loss was detected on OCT by assessing the retinal ganglion cell layer. PMID:25285723

  5. Ganglion cell complex thickness in nonexudative age-related macular degeneration

    PubMed Central

    Yenice, E; Şengün, A; Soyugelen Demirok, G; Turaçlı, E

    2015-01-01

    Purpose To evaluate ganglion cell complex (GCC) thickness with spectral domain optical coherence tomography (SD-OCT) in eyes with nonexudative age-related macular degeneration (NEAMD). Methods Forty-seven eyes of 28 patients with nonexudative age-related macular degeneration (NEAMD) and 54 eyes of 28 age-matched healthy subjects were enrolled. Each subject underwent a complete ophthalmic examination before SD-OCT were obtained. Macular scans were taken with software version 6.0 of the ganglion cell analysis (GCA) algorithm. GCC thickness was evaluated automatically as the average, minimum, temporal superior, superior, nasal superior, nasal inferior, inferior, and temporal-inferior segments by SD-OCT and parameters were compared between groups. Results The mean age was 68.7±8.73 years in patient group, and 61.51±5.66 years in control group. There were no significant differences in mean age, gender distribution, intraocular pressure, and sferic equivalent at imaging between the groups (P>0.05). The mean (±SD) GCC thicknesses were as follows; average 71.53±16.53 μm, minumum 62.36±21.51 μm, temporal superior 72.23±14.60 μm, superior 72.76±20.40 μm, nasal superior 72.31±20.13 μm, nasal inferior 69.74±20.51 μm, inferior 69.38±19.03 μm, and temporal-inferior 73.12±15.44 μm in patient group. Corresponding values in control group were 81.46±4.90 μm, 78.66±6.00 μm, 81.51±4.66 μm, 82.94±5.14 μm, 81.79±5.86 μm, 80.94±6.18 μm, 80.14±6.30 μm, and 81.75±5.26 μm, respectively. There were significant differences between two groups in each segments (Mann–Whitney U-test, P<0.05). Conclusion The average GCC thickness values (in all segments) of NEAMD patients were lower than control group. NEAMD, which is considered as a disease of outer layers of retina, may be accompanied with a decrease of ganglion cell thickness, so inner layers of retina may be affected. PMID:26021868

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

    PubMed Central

    Ahluwalia, Vandana V; DayanandaSagar, G; Narayan, Shamrendra; Gupta, Arun

    2014-01-01

    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. PMID:27298942

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

    PubMed

    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. PMID:25912998

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

    PubMed Central

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

    2015-01-01

    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. PMID:25912998

  9. Spiral ganglion degeneration and hearing loss as a consequence of satellite cell death in saposin B-deficient mice.

    PubMed

    Akil, Omar; Sun, Ying; Vijayakumar, Sarath; Zhang, Wujuan; Ku, Tiffany; Lee, Chi-Kyou; Jones, Sherri; Grabowski, Gregory A; Lustig, Lawrence R

    2015-02-18

    Saposin B (Sap B) is an essential activator protein for arylsulfatase A in the hydrolysis of sulfatide, a lipid component of myelin. To study Sap B's role in hearing and balance, a Sap B-deficient (B(-/-)) mouse was evaluated. At both light and electron microscopy (EM) levels, inclusion body accumulation was seen in satellite cells surrounding spiral ganglion (SG) neurons from postnatal month 1 onward, progressing into large vacuoles preceding satellite cell degeneration, and followed by SG degeneration. EM also revealed reduced or absent myelin sheaths in SG neurons from postnatal month 8 onwards. Hearing loss was initially seen at postnatal month 6 and progressed thereafter for frequency-specific stimuli, whereas click responses became abnormal from postnatal month 13 onward. The progressive hearing loss correlated with the accumulation of inclusion bodies in the satellite cells and their subsequent degeneration. Outer hair cell numbers and efferent function measures (distortion product otoacoustic emissions and contralateral suppression) were normal in the B(-/-) mice throughout this period. Alcian blue staining of SGs demonstrated that these inclusion bodies corresponded to sulfatide accumulation. In contrast, changes in the vestibular system were much milder, but caused severe physiologic deficits. These results demonstrate that loss of Sap B function leads to progressive sulfatide accumulation in satellite cells surrounding the SG neurons, leading to satellite cell degeneration and subsequent SG degeneration with a resultant loss of hearing. Relative sparing of the efferent auditory and vestibular neurons suggests that alternate glycosphingolipid metabolic pathways predominate in these other systems. PMID:25698761

  10. Activation of TLR3 Promotes the Degeneration of Retinal Ganglion Cells by Upregulating the Protein Levels of JNK3

    PubMed Central

    Chintala, Shravan K.; Putris, Nahrain; Geno, Mason

    2015-01-01

    Purpose. To investigate whether activation of Toll-like receptor 3 (TLR3) promotes the degeneration of retinal ganglion cells (RGCs) by upregulating the protein levels of c-jun N-terminal kinase 3 (JNK3). Methods. Toll-like receptor 3-specific activator, Poly(I:C) (polyinosinic-polycytidylic acid), or PBS was injected into the vitreous humor of Thy1-YFP mice. At 24, 48, and 72 hours after treatments, degeneration of RGCs was assessed by using antibodies against brain-specific homeobox/POU domain protein 3a (Brn3a). A TLR3-specific inhibitor was injected into the vitreous humor with or without Poly(I:C). Western blot assays were performed to determine relative levels of TLR3, JNK3, pJNK3, and sterile alpha and HEAT/Armadillo motif-containing 1 (SARM1) proteins in retinal protein extracts, and immunohistochemistry assays were performed to determine their cellular localization in the retina. Mouse eyes were treated with Poly(I:C) or PBS along with MitoTracker Red, and colocalization of MitoTracker Red and JNK3 in the retinas was determined by using antibodies against JNK3. Results. Poly(I:C) activated TLR3 and upregulated its downstream target protein JNK3 but not SARM1 in the retina. Poly(I:C) activated TLR3 and upregulated JNK3 specifically in RGCs and promoted a significant degeneration of RGCs over a 72-hour time period. Toll-like receptor 3 upregulated the levels of JNK3 protein in the cytoplasm of RGCs, but not in the mitochondria. Toll-like receptor 3-specific inhibitor downregulated Poly(I:C)-mediated upregulation of JNK3 protein, and, in turn, significantly attenuated TLR3-induced degeneration of RGCs. Conclusions. Results presented in this study show that the activation of TLR3 alone promotes the degeneration of RGCs by upregulating the protein levels of JNK3. PMID:25564448

  11. Tissue and urokinase plasminogen activators instigate the degeneration of retinal ganglion cells in a mouse model of glaucoma.

    PubMed

    Chintala, Shravan K

    2016-02-01

    Elevated intraocular pressure (IOP) promotes the degeneration of retinal ganglion cells (RGCs) during the progression of Primary Open-Angle Glaucoma (POAG). However, the molecular mechanisms underpinning IOP-mediated degeneration of RGCs remain unclear. Therefore, by employing a mouse model of POAG, this study examined whether elevated IOP promotes the degeneration of RGCs by up-regulating tissue plasminogen activator (tPA) and urokinase plasminogen activator (uPA) in the retina. IOP was elevated in mouse eyes by injecting fluorescent-microbeads into the anterior chamber. Once a week, for eight weeks, IOP in mouse eyes was measured by using Tono-Pen XL. At various time periods after injecting microbeads, proteolytic activity of tPA and uPA in retinal protein extracts was determined by fibrinogen/plasminogen zymography assays. Localization of tPA and uPA, and their receptor LRP-1 (low-density receptor-related protein-1) in the retina was determined by immunohistochemistry. RGCs' degeneration was assessed by immunostaining with antibodies against Brn3a. Injection of microbeads into the anterior chamber led to a progressive elevation in IOP, increased the proteolytic activity of tPA and uPA in the retina, activated plasminogen into plasmin, and promoted a significant degeneration of RGCs. Elevated IOP up-regulated tPA and LRP-1 in RGCs, and uPA in astrocytes. At four weeks after injecting microbeads, RAP (receptor associated protein; 0.5 and 1.0 μM) or tPA-Stop (1.0 and 4.0 μM) was injected into the vitreous humor. Treatment of IOP-elevated eyes with RAP led to a significant decrease in proteolytic activity of both tPA and uPA, and a significant decrease in IOP-mediated degeneration of RGCs. Also, treatment of IOP-elevated eyes with tPA-Stop decreased the proteolytic activity of both tPA and uPA, and, in turn, significantly attenuated IOP-mediated degeneration of RGCs. Results presented in this study provide evidence that elevated IOP promotes the degeneration of

  12. Attenuated infrared neuron stimulation response in cochlea of deaf animals may associate with the degeneration of spiral ganglion neurons

    PubMed Central

    Xie, Bingbin; Dai, Chunfu; Li, Huawei

    2015-01-01

    Hypothesis: We hypothesize that degenerated spiral ganglion neurons (SGNs) in guinea pigs reduces auditory brainstem responses evoked by pulsed infrared stimulation. Background: Pulsed infrared laser excitation can directly evoke physiological responses in neuronal and other excitable cells in vivo and in vitro. Laser pulses could benefit patients with cochlear implants to stimulate the auditory system. Methods: Pulsed infrared lasers were used to study evoked optical auditory brainstem responses (oABRs) in normal hearing and deafened animals. Aslo, the morphology and anatomy of SGNs in normal hearing and deafened guinea pigs were compared. Results: By recording oABRs evoked by varying infrared laser pulse durations, it is suggested that degeneration of SGNs in deafened guinea pigs was associated with an elevated oABR threshold and with lower amplitudes. Moreover, oABR threshold decreased while amplitudes increased in both normal hearing and deafened animals as the pulse duration prolonged. Electron microscopy revealed that SGNs in deafened guinea pigs had swollen and vacuolar mitochondria, as well as demyelinated soma and axons. Conclusion: Infrared laser pulses can stimulate SGNs to evoke oABRs in guinea pigs. Deafened guinea pigs have elevated thresholds and smaller amplitude responses, likely a result of degenerated SGNs. Short pulse durations are more suitable to evoke responses in both normal hearing and deafened animals. PMID:26114024

  13. Complimentary action: C1q increases ganglion cell survival in an in vitro model of retinal degeneration.

    PubMed

    Taylor, Linnéa; Arnér, Karin; Blom, Anna M; Ghosh, Fredrik

    2016-09-15

    Using a previously described retinal explant culture system as an acute injury model, we here explore the role of C1q, the initiator of the classical complement pathway, in neuronal cell survival and retinal homeostasis. Full-thickness adult rat retinal explants were divided into four groups, receiving the following supplementation: C1q (50nM), C1-inhibitor (C1-inh; Berinert; 500mg/l), C1q+C1-inh, and no supplementation (culture controls). Explants were kept for 12h or 2days after which they were examined morphologically and with a panel of immunohistochemical markers. C1q supplementation protects ganglion cells from degeneration within the explant in vitro system. This effect is correlated to an attenuated endogenous production of C1q, and a quiesced gliotic response. PMID:27609284

  14. Effect of Stimulus Waveform of Biphasic Current Pulse on Retinal Ganglion Cell Responses in Retinal Degeneration (rd1) mice

    PubMed Central

    Ahn, Kun No; Ahn, Jeong Yeol; Kim, Jae-hyung; Cho, Kyoungrok; Koo, Kyo-in; Senok, Solomon S.

    2015-01-01

    A retinal prosthesis is being developed for the restoration of vision in patients with retinitis pigmentosa (RP) and age-related macular degeneration (AMD). Determining optimal electrical stimulation parameters for the prosthesis is one of the most important elements for the development of a viable retinal prosthesis. Here, we investigated the effects of different charge-balanced biphasic pulses with regard to their effectiveness in evoking retinal ganglion cell (RGC) responses. Retinal degeneration (rd1) mice were used (n=17). From the ex-vivo retinal preparation, retinal patches were placed ganglion cell layer down onto an 8×8 multielectrode array (MEA) and RGC responses were recorded while applying electrical stimuli. For asymmetric pulses, 1st phase of the pulse is the same with symmetric pulse but the amplitude of 2nd phase of the pulse is less than 10 µA and charge balanced condition is satisfied by lengthening the duration of the pulse. For intensities (or duration) modulation, duration (or amplitude) of the pulse was fixed to 500 µs (30 µA), changing the intensities (or duration) from 2 to 60 µA (60 to 1000 µs). RGCs were classified as response-positive when PSTH showed multiple (3~4) peaks within 400 ms post stimulus and the number of spikes was at least 30% more than that for the immediate pre-stimulus 400 ms period. RGC responses were well modulated both with anodic and cathodic phase-1st biphasic pulses. Cathodic phase-1st pulses produced significantly better modulation of RGC activity than anodic phase-1st pulses regardless of symmetry of the pulse. PMID:25729279

  15. Human organotypic retinal cultures (HORCs) as a chronic experimental model for investigation of retinal ganglion cell degeneration.

    PubMed

    Osborne, Andrew; Hopes, Marina; Wright, Phillip; Broadway, David C; Sanderson, Julie

    2016-02-01

    There is a growing need for models of human diseases that utilise native, donated human tissue in order to model disease processes and develop novel therapeutic strategies. In this paper we assessed the suitability of adult human retinal explants as a potential model of chronic retinal ganglion cell (RGC) degeneration. Our results confirmed that RGC markers commonly used in rodent studies (NeuN, βIII Tubulin and Thy-1) were appropriate for labelling human RGCs and followed the expected differential expression patterns across, as well as throughout, the macular and para-macular regions of the retina. Furthermore, we showed that neither donor age nor post-mortem time (within 24 h) significantly affected the initial expression levels of RGC markers. In addition, the feasibility of using human post mortem donor tissue as a long-term model of RGC degeneration was determined with RGC protein being detectable up to 4 weeks in culture with an associated decline in RGC mRNA and significant, progressive, apoptotic labelling of NeuN(+) cells. Differences in RGC apoptosis might have been influenced by medium compositions indicating that media constituents could play a role in supporting axotomised RGCs. We propose that using ex vivo human explants may prove to be a useful model for testing the effectiveness of neuroprotective strategies. PMID:26432917

  16. Undersized Dendritic Arborizations in Retinal Ganglion Cells of the Rd1 Mutant Mouse: A Paradigm of Early Onset Photoreceptor Degeneration*

    PubMed Central

    Damiani, Devid; Novelli, Elena; Mazzoni, Francesca; Strettoi, Enrica

    2014-01-01

    Retinitis pigmentosa (RP) is a family of inherited diseases causing progressive photoreceptor death. Retinal ganglion cells (RGCs) form the biological substrate for various therapeutic approaches designed to restore vision in RP individuals. Assessment of survival and preservation of RGCs in animal paradigms mimicking the human disease is of key importance for appropriate implementation of vision repair strategies. Here we studied the survival of RGCs in the rd1 mutant mouse, a known model of early onset, autosomic recessive RP, at various stages of photoreceptor degeneration. Furthermore, we analyzed the morphology of various types of RGCs using the newly generated transgenic mouse rd1/Thy1-GFP, in which the rd1 mutation is associated with green fluorescent protein (GFP) expression in a small population of different RGCs. We found excellent survival of cells at up to 1 year of age, a time at which the inner retina is known to have severely reorganized and partially degenerated. However, 50% of the cells analyzed within all RGC types exhibit an undersized dendritic tree, spanning about half of the normal area. Undersized cells are found both in adult and in very young (1-month-old) mice. This suggests that their aberrant phenotype is due to incomplete dendritic development, possibly as a consequence of altered visual input at the time of dendritic arbor refinement. These data show the importance of the timing of photoreceptor death in RGC dendritic development. PMID:22102216

  17. Axonal degeneration, regeneration and ganglion cell death in a rodent model of anterior ischemic optic neuropathy (rAION).

    PubMed

    Zhang, Cheng; Guo, Yan; Slater, Bernard J; Miller, Neil R; Bernstein, Steven L

    2010-08-01

    Using laser-induced photoactivation of intravenously administered rose Bengal in rats, we generated an ischemic infarction of the intrascleral portion of the optic nerve (ON) comparable to that which occurs in humans to investigate optic nerve axon degenerative events following optic nerve infarct and the potential for axon re-growth. Animals were euthanized at different times post infarct. Axon degeneration was evaluated with SMI312 immunolabeling, and GAP-43 immunostaining was used to identify axon regeneration. Terminal dUTP nick end labeling (TUNEL) was used to evaluate retinal ganglion cell (RGC) death. There was significant axon structural disruptinot ion at the anterior intrascleral portion of the ON by 3d post-infarct, extending to the posterior ON by 7d post-stroke. Destruction of normal axon structure and massive loss of axon fibers occurred by 2 weeks. GAP-43 immunoreactivity occurred in the anterior ON by 7d post-infarct, lasting 3-4 weeks, without extension past the primary ischemic lesion. TUNEL-positive cells in the RGC layer appeared by 7d post-insult. These results indicate that following induction of ischemic optic neuropathy, significant axon damage occurs by 3d post-infarct, with later neuronal death. Post-stroke adult rat retinal ganglion cells attempt to regenerate their axons, but this effort is restricted to the unmyelinated region of the anterior ON. These responses are important in understanding pathologic process that underlies human non-arteritic anterior ischemic optic neuropathy (NAION) and may guide both the appropriate treatment of NAION and the window of opportunity for such treatment. PMID:20621651

  18. Sectorial loss of retinal ganglion cells in inherited photoreceptor degeneration is due to RGC death

    PubMed Central

    García-Ayuso, Diego; Salinas-Navarro, Manuel; Nadal-Nicolás, Francisco Manuel; Ortín-Martínez, Arturo; Agudo-Barriuso, Marta; Vidal-Sanz, Manuel; Villegas-Pérez, María P

    2014-01-01

    Aims To investigate the cause of retinal ganglion cell (RGC) loss in dystrophic aged Royal College of Surgeons (RCS) rats. Methods RCS-p+ (dystrophic) female rats of postnatal times (P365, P450 and P540) and age-matched RCS-p1 rdy+ (non-dystrophic) rats were used. In whole-mounted retinas, RGCs were doubly labelled with Fluorogold (FG) retrogradely transported from the superior colliculi and Brn3a immunohistochemistry. RGC axons were labelled with anti-neurofilament antibodies. Automatic image analysis techniques allowed quantification of the total population of RGCs per retina and construction of isodensity maps to investigate RGC topology. Results Dystrophic retinas showed at all times studied wedge-shaped sectors devoid of FG+ and Brn3a+ RGCs. These sectors were also devoid of neurofilament-labelled axons. The total number of FG+RGC and Brn3a+RGC per retina was significantly smaller in dystrophic rats at P540, revealing RGC death at this age. The total number of FG+RGCs was smaller than those of Brn3a+RGCs at P540, indicating a disturbance of the retrograde axonal transport at this age. Conclusions RGC double labelling documents that sectorial RGC loss in aged dystrophic RCS rats is mainly due to RGC death, although a deficit of the retrograde axonal transport exists also at the more advanced ages. PMID:24326325

  19. Mutant WDR36 directly affects axon growth of retinal ganglion cells leading to progressive retinal degeneration in mice

    PubMed Central

    Chi, Zai-Long; Yasumoto, Fumie; Sergeev, Yuri; Minami, Masayoshi; Obazawa, Minoru; Kimura, Itaru; Takada, Yuichiro; Iwata, Takeshi

    2010-01-01

    Primary open-angle glaucoma (POAG) is one of the three principal subtypes of glaucoma and among the leading cause of blindness worldwide. POAG is defined by cell death of the retinal ganglion cells (RGCs) and surrounding neuronal cells at higher or normal intraocular pressure (IOP). Coded by one of the three genes responsible for POAG, WD repeat-containing protein 36 (WDR36) has two domains with a similar folding. To address whether WDR36 is functionally important in the retina, we developed four transgenic mice strains overexpressing a wild-type (Wt) and three mutant variants of D606G, deletion of amino acids at positions 605–607 (Del605–607) and at 601–640 (Del601–640) equivalent to the location of the D658G mutation observed in POAG patients. A triple amino acid deletion of mouse Wdr36 at positions 605–607 corresponding to the deletion at positions 657–659 in humans developed progressive retinal degeneration at the peripheral retina with normal IOP. RGCs and connecting amacrine cell synapses were affected at the peripheral retina. Axon outgrowth rate of cultured RGC directly isolated from transgenic animal was significantly reduced by the Wdr36 mutation compared with Wt. Molecular modeling of wild and mutant mouse Wdr36 revealed that deletion at positions 605–607 removed three residues and a hydrogen bond, required to stabilize anti-parallel β-sheet of the 6th β-propeller in the second domain. We concluded that WDR36 plays an important functional role in the retina homeostasis and mutation to this gene can cause devastating retinal damage. These data will improve understanding of the functional property of WDR36 in the retina and provide a new animal model for glaucoma therapeutics. PMID:20631153

  20. Ganglion Cell Complex Evaluation in Exudative Age-Related Macular Degeneration after Repeated Intravitreal Injections of Ranibizumab.

    PubMed

    Perdicchi, Andrea; Peluso, Giacomo; Iacovello, Daniela; Balestrieri, Marco; Delle Fave, Martina; Abdolrahimzadeh, Solmaz; Scuderi, Gian Luca; Fenicia, Vito; Recupero, Santi Maria

    2015-01-01

    Purpose. To detect the effects of intravitreal ranibizumab injections on GCC in patients with wet AMD. Methods. 32 wet AMD eyes were selected and submitted at three ranibizumab injections. RTVue-OCT GCC and MM5 protocol were performed before treatment and twenty days after each injection. Results. At baseline mean GCC thickness was 93.9 ± 18.5 μm. Twenty days after each intravitreal injection it was, respectively, 85.8 ± 10.1, 86.5 ± 9.3, and 91.1 ± 11.5 μm, without statistical significance. A significant improvement in visual acuity (P = 0.031) and a reduction of mean foveal (P = 0.001) and macular thickness (P = 0.001) were observed. Conclusion. The clinical results confirm therapeutic efficacy of intravitreal injections of ranibizumab in wet AMD. A contemporary not statistically significant reduction of GCC thickness suggests that the loading phase of ranibizumab does not have any toxic effects on ganglion cell complex. PMID:26167478

  1. Ganglion Cell Complex Evaluation in Exudative Age-Related Macular Degeneration after Repeated Intravitreal Injections of Ranibizumab

    PubMed Central

    Perdicchi, Andrea; Peluso, Giacomo; Iacovello, Daniela; Balestrieri, Marco; Delle Fave, Martina; Abdolrahimzadeh, Solmaz; Scuderi, Gian Luca; Fenicia, Vito; Recupero, Santi Maria

    2015-01-01

    Purpose. To detect the effects of intravitreal ranibizumab injections on GCC in patients with wet AMD. Methods. 32 wet AMD eyes were selected and submitted at three ranibizumab injections. RTVue-OCT GCC and MM5 protocol were performed before treatment and twenty days after each injection. Results. At baseline mean GCC thickness was 93.9 ± 18.5 μm. Twenty days after each intravitreal injection it was, respectively, 85.8 ± 10.1, 86.5 ± 9.3, and 91.1 ± 11.5 μm, without statistical significance. A significant improvement in visual acuity (P = 0.031) and a reduction of mean foveal (P = 0.001) and macular thickness (P = 0.001) were observed. Conclusion. The clinical results confirm therapeutic efficacy of intravitreal injections of ranibizumab in wet AMD. A contemporary not statistically significant reduction of GCC thickness suggests that the loading phase of ranibizumab does not have any toxic effects on ganglion cell complex. PMID:26167478

  2. Calpain-1 and calpain-2 play opposite roles in retinal ganglion cell degeneration induced by retinal ischemia/reperfusion injury.

    PubMed

    Wang, Yubin; Lopez, Dulce; Davey, Pinakin Gunvant; Cameron, D Joshua; Nguyen, Katherine; Tran, Jennifer; Marquez, Elizabeth; Liu, Yan; Bi, Xiaoning; Baudry, Michel

    2016-09-01

    Calpain has been shown to be involved in neurodegeneration, and in particular in retinal ganglion cell (RGC) death resulting from increased intraocular pressure (IOP) and ischemia. However, the specific roles of the two major calpain isoforms, calpain-1 and calpain-2, in RGC death have not been investigated. Here, we show that calpain-1 and calpain-2 were sequentially activated in RGC dendrites after acute IOP elevation. By combining the use of a selective calpain-2 inhibitor (C2I) and calpain-1 KO mice, we demonstrated that calpain-1 activity supported survival, while calpain-2 activity promoted cell death of RGCs after IOP elevation. Calpain-1 activation cleaved PH domain and leucine-rich repeat protein phosphatase 1 (PHLPP1) and activated the Akt pro-survival pathway, while calpain-2 activation cleaved striatal-enriched protein tyrosine phosphatase (STEP) and activated STEP-mediated pro-death pathway in RGCs after IOP elevation. Systemic or intravitreal C2I injection to wild-type mice 2h after IOP elevation promoted RGC survival and improved visual function. Our data indicate that calpain-1 and calpain-2 play opposite roles in high IOP-induced ischemic injury and that a selective calpain-2 inhibitor could prevent acute glaucoma-induced RGC death and blindness. PMID:27185592

  3. Semimembranosus ganglion cyst

    PubMed Central

    Kannadath, Bijun Sai; Soundamourthy, Sandosh; Subramanian, Aruna; Sinhasan, Sankappa P.; Bhat, Ramachandra V.

    2014-01-01

    Ganglion cysts are tumor-like lesions in the soft tissues, generated by mucoid degeneration of the joint capsule, tendon or tendon sheaths on the dorsum of hand, wrist and foot. However, an intratendinous origin for a ganglion cyst is extremely rare. During dissection of the popliteal fossa, a cyst of 2.5 cm×2 cm×0.5 cm was observed in the tendon of right semimembranosus, 3.5 cm above the insertion of the muscle. Contrast X-ray revealed the cyst as not communicating with the knee joint or any adjacent bursae. Histopathological examination confirmed the diagnosis of ganglion cyst. PMID:25276481

  4. Rotenone causing dysfunctional mitochondria and lysosomes in cerebral ganglions of Lumbricus terrestris degenerate giant fibers and neuromuscular junctions.

    PubMed

    Subaraja, Mamangam; Vanisree, Arambakkam Janardhanam

    2016-06-01

    Rotenone is well-documented to cause neurodegenerative condition such as Parkinson's, in the exposed systems. However, its detrimental effect on particular sites of neuronal pathway is still under investigation. We aimed at elucidating the impact of rotenone on cerebral ganglions (CG) of Lumbricus terrestris which control movement and behaviour of the worms. Worms were exposed to 0-0.4 ppm/mL of rotenone. Mitochondrial and lysosomal integrities were found to be affected beyond 0.2 ppm/mL of rotenone. Activities of cholinergic enzymes and the expression of tyrosine hydroxylase showed an impaired neuronal transmission in CGs at the dose of 0.2 ppm/mL of rotenone. Histopathological and immunoflourescent analyses showed neuronal apoptosis, reduced nucleic acid content and inhibited of neurosecretion at 0.3 ppm/mL. Electron microscopy showed that the neurons and neuromuscular junctions were affected at 0.2 ppm/mL. Dose-dependent changes were also observed in the motor function such as burrowing behaviours and locomotion. Conduction velocity (CV) and locomotion assessment showed that the CV of lateral giant fiber (LGF) was reduced while that of MGF remains unaffected at 0.2 ppm, the dose at which the burrowing behaviour was also not affected. LGF, cholinergic enzymes and tyrosine hydroxylase are primarily targeted by rotenone affecting locomotion at 0.2 ppm/mL while MGF, neuropile and the burrowing behaviour were affected at 0.3 ppm/mL. We demonstrate, in addition to dose-dependent effects, that the bioaccumulation factors range 0.28-0.32 ppm/μg of rotenone cause degenerative impact on giant fibers affecting neuronal behaviors/locomotion of worms. We also propose worms for studying mechanisms of neuronal pathology caused by chemicals prevailing in earth's atmosphere. PMID:27003369

  5. The impact of L5 dorsal root ganglion degeneration and Adamkiewicz artery vasospasm on descending colon dilatation following spinal subarachnoid hemorrhage: An experimental study; first report

    PubMed Central

    Ozturk, Cengiz; Kanat, Ayhan; Aydin, Mehmet Dumlu; Yolas, Coskun; Kabalar, Mehmet Esref; Gundogdu, Betul; Duman, Aslihan; Kanat, Ilyas Ferit; Gundogdu, Cemal

    2015-01-01

    Context: Somato-sensitive innervation of bowels are maintained by lower segments of spinal cord and the blood supply of the lower spinal cord is heavily dependent on Adamkiewicz artery. Although bowel problems are sometimes seen in subarachnoid hemorrhage neither Adamkiewicz artery spasm nor spinal cord ischemia has not been elucidated as a cause of bowel dilatation so far. Aims: The goal of this study was to study the effects Adamkiewicz artery (AKA) vasospasm in lumbar subarachnoid hemorrhage (SAH) on bowel dilatation severity. Settings and Design: An experimental rabbit study. Materials and Methods: The study was conducted on 25 rabbits, which were randomly divided into three groups: Spinal SAH (N = 13), serum saline (SS) (SS; N = 7) and control (N = 5) groups. Experimental spinal SAH was performed. After 21 days, volume values of descending parts of large bowels and degenerated neuron density of L5DRG were analyzed. Statistical Analysis Used: Statistical analysis was performed using the PASW Statistics 18.0 for Windows (SPSS Inc., Chicago, Illinois). Two-tailed t-test and Mann-Whitney U-tests were used. The statistical significance was set at P < 0.05. Results: The mean volume of imaginary descending colons was estimated as 93 ± 12 cm3 in the control group and 121 ± 26 cm3 in the SS group and 176 ± 49 cm3 in SAH group. Volume augmentations of the descending colons and degenerated neuron density L5DRG were significantly different between the SAH and other two groups (P < 0.05). Conclusion: An inverse relationship between the living neuronal density of the L5DRG and the volume of imaginary descending colon values was occurred. Our findings will aid in the planning of future experimental studies and determining the clinical relevance on such studies. PMID:25972712

  6. Hair Cell Loss, Spiral Ganglion Degeneration, and Progressive Sensorineural Hearing Loss in Mice with Targeted Deletion of Slc44a2/Ctl2.

    PubMed

    Kommareddi, Pavan; Nair, Thankam; Kakaraparthi, Bala Naveen; Galano, Maria M; Miller, Danielle; Laczkovich, Irina; Thomas, Trey; Lu, Lillian; Rule, Kelli; Kabara, Lisa; Kanicki, Ariane; Hughes, Elizabeth D; Jones, Julie M; Hoenerhoff, Mark; Fisher, Susan G; Altschuler, Richard A; Dolan, David; Kohrman, David C; Saunders, Thomas L; Carey, Thomas E

    2015-12-01

    SLC44A2 (solute carrier 44a2), also known as CTL2 (choline transporter-like protein 2), is expressed in many supporting cell types in the cochlea and is implicated in hair cell survival and antibody-induced hearing loss. In mice with the mixed C57BL/6-129 background, homozygous deletion of Slc44a2 exons 3–10 (Slc44a2(Δ/Δ)resulted in high-frequency hearing loss and hair cell death. To reduce effects associated with age-related hearing loss (ARHL) in these strains, mice carrying the Slc44a2Δ allele were backcrossed to the ARHL-resistant FVB/NJ strain and evaluated after backcross seven(N7) (99 % FVB). Slc44a2(Δ/Δ) mice produced abnormally spliced Slc44a2 transcripts that contain a frame shift and premature stop codons. Neither full-length SLC44A2 nor a putative truncated protein could be detected in Slc44a2(Δ/Δ) mice, suggesting a likely null allele. Auditory brain stem responses (ABRs) of mice carrying the Slc44a2Δ allele on an FVB/NJ genetic background were tested longitudinally between the ages of 2 and 10 months. By 6 months of age,Slc44a2(Δ/Δ) mice exhibited hearing loss at 32 kHz,but at 12 and 24 kHz had sound thresholds similar to those of wild-type Slc44a2(+/+) and heterozygous +/Slc44a2Δ mice. After 6 months of age, Slc44a2(Δ/Δ) mutants exhibited progressive hearing loss at all frequencies and +/Slc44a2(Δ) mice exhibited moderate threshold elevations at high frequency. Histologic evaluation of Slc44a2(Δ/Δ) mice revealed extensive hair cell and spiral ganglion cell loss, especially in the basal turn of the cochlea. We conclude that Slc44a2 function is required for long-term hair cell survival and maintenance of hearing. PMID:26463873

  7. Symptomatic intratendinous ganglion cyst of the patellar tendon.

    PubMed

    Jose, Jean; O'Donnell, Kevin; Lesniak, Bryson

    2011-02-01

    Ganglion cysts have been previously described throughout the body, most commonly about the wrist, hand, knee, ankle, and feet. When symptomatic, they may interfere with joint mechanics, resulting in snapping, catching, and locking. Intratendinous ganglion cysts lack a synovial epithelial lining and are thought to develop from the mucoid degeneration of connective tissue caused by chronic irritation, chronic repetitive injury, and chronic ischemia. On magnetic resonance imaging, ganglion cysts originating from tendons, ligaments, tendon sheaths, menisci, or joint capsules appear as well-defined lobulated masses that follow simple or complex fluid signal intensity on all pulse sequences, with enhancing walls and internal septations on post-contrast images. There may be appreciable degeneration and partial tearing of the structure of origin, particularly if associated with tendons. On ultrasonography, they present as hypoechoic masses, with internal septations and lobulations of varying sizes, without significant vascularity on power or color Doppler sampling. A thin fluid neck extending from the structure of origin (tail sign), when present, is a reliable sign of a ganglion cyst. This article describes a sonographically guided technique to treat symptomatic ganglion cysts within the patellar tendon. Complete evacuation of the ganglion cyst, with disappearance of the tail sign, is considered the determining factor for a successful procedure. A similar technique can be used for the treatment of other symptomatic intratendinous ganglion cysts elsewhere in the body. To our knowledge, symptomatic intratendinous ganglion cysts within the patellar tendon and their treatment have not been previously reported. PMID:21323277

  8. [Intrinsically Photosensitive Retinal Ganglion Cells].

    PubMed

    Skorkovská, K; Skorkovská, Š

    2015-06-01

    Recently discovered intrinsically photosensitive melanopsin-containing retinal ganglion cells contribute to circadian photoentrainment and pupillary constriction; recent works have also brought new evidence for their accessory role in the visual system in humans. Pupil light reaction driven by individual photoreceptors can be isolated by means of the so called chromatic pupillography. The use of chromatic stimuli to elicit different pupillary responses may become an objective clinical pupil test in the detection of retinal diseases and in assessing new therapeutic approaches particularly in hereditary retinal degenerations like retinitis pigmentosa. In advanced stages of disease, the pupil light reaction is even more sensitive than standard electroretinography for detecting residual levels of photoreceptor activity. This review summarizes current knowledge on intrinsically photosensitive retinal cells and highlights its possible implications for clinical practice. PMID:26201360

  9. Macular degeneration

    MedlinePlus Videos and Cool Tools

    ... at the center of the field of vision. Macular degeneration results from a partial breakdown of the insulating ... choroid layer of blood vessels behind the retina. Macular degeneration results in the loss of central vision only.

  10. Cerebellar Degeneration

    MedlinePlus

    ... Degeneration? Cerebellar degeneration is a process in which neurons in the cerebellum - the area of the brain ... proteins that are necessary for the survival of neurons. Associated diseases: Diseases that are specific to the ...

  11. Aging rat vestibular ganglion: I. Quantitative light microscopic evaluation.

    PubMed

    Alidina, A; Lyon, M J

    1990-01-01

    This study was undertaken to quantify age-related changes in the rat vestibular ganglion. Cell number, diameter, and proximal-distal distribution based on size were evaluated. Serial 5-microns plastic sections of the vestibular ganglion from 15 female Wistar rats were examined. Rats were divided into three age groups: young (Y, 3 to 5 months, n = 5), old (0, 24 to 26 months, n = 3), and very old (VO, 28 to 31 months, n = 7). Quantitative analysis indicated no significant differences (P less than .05) in the estimated number of ganglion cells (mean: Y = 1,690, 0 = 2,257, VO = 1,678), ganglion cell profile diameters (mean: Y = 22.5 microns, n = 2,886; O = 23.7 microns, n = 2,313; VO = 22.8 microns, n = 4,061), or proximal-distal localization (proximal: 22.3 microns, 24.4 microns, 22.7 microns; middle: 22.6 microns, 23.1 microns, 22.4 microns; distal: 23.3 microns, 23.4 microns, 23.7 microns; Y, O, and VO, respectively). When pooled, the old animals tended to have slightly larger cell profiles than the other groups. We noted a dramatic age-related increase of aging pigment within the ganglion cell profiles, making the old and very old animals easily distinguishable from the young. In most of the cell profiles, the aging pigment was more or less uniformly distributed throughout the cytoplasm. However, in some, aging pigment was accumulated at one pole of the cell profile. While no typical degenerating cellular profiles were found in any of the sections, several of the ganglion cell profiles from the old animals revealed dense cytoplasm, possibly indicating an early stage of degeneration. PMID:2382785

  12. [Cortico-basal ganglia circuits--parallel closed loops and convergent/divergent connections].

    PubMed

    Miyachi, Shigehiro

    2009-04-01

    The basal ganglia play important roles not only in motor control but also in higher cognitive functions such as reinforcement learning and procedural memory. Anatomical studies on the neuronal connections between the basal ganglia, cerebral cortex, and thalamus have demonstrated that these nuclei and cortical areas are interconnected via independent parallel loop circuits. The association, motor, and limbic cortices project to specific domains in the striatum, which, in turn, project back to the corresponding cortical areas via the substantia nigra/globus pallidus and the thalamus. Likewise, subregions in the motor cortex representing different body parts project to specific regions in the putamen, which project back to the original motor cortical regions. These parallel loops have been thought to be the basic anatomical structures involved in the basal ganglia functions. Furthermore, neuronal projections communicating between different loops (or functional domains) have also been discovered. A considerable number of corticostriatal projections from functionally interrelated cortical areas (e. g., hand representations of the motor cortex and somatosensory cortex) converge at the striatum. It has also been suggested that the location of the substantia nigra is in such that it can transmit information from the 'limbic loop' to the 'association loop', and from the 'association loop' to the 'motor loop'. Furthermore, a recent transsynaptic neuronal tracing study conducted at our laboratory demonstrated that the ventral (limbic) striatum sends divergent outputs to multiple regions in the frontal cortex. These 'inter-loop' connections would be important for the integration of information to achieve goal-directed behaviors. PMID:19378804

  13. The place of dopamine in the cortico-basal ganglia circuit.

    PubMed

    Haber, S N

    2014-12-12

    The midbrain dopamine (DA) neurons play a central role in developing appropriate goal-directed behaviors, including the motivation and cognition to develop appropriate actions to obtain a specific outcome. Indeed, subpopulations of DA neurons have been associated with these different functions: the mesolimbic, mesocortical, and nigrostriatal pathways. The mesolimbic and nigrostriatal pathways are an integral part of the basal ganglia through its reciprocal connections to the ventral and dorsal striatum respectively. This chapter reviews the connections of the midbrain DA cells and their role in integrating information across limbic, cognitive and motor functions. Emphasis is placed on the interface between these functional domains within the striatum through corticostriatal connections, through the striato-nigro-striatal connection, and through the lateral habenula projection to the midbrain. PMID:25445194

  14. Treatment of Ganglion Cysts

    PubMed Central

    Fung, B.; Lung, C. P.

    2013-01-01

    Ganglion cysts are soft tissue swellings occurring most commonly in the hand or wrist. Apart from swelling, most cysts are asymptomatic. Other symptoms include pain, weakness, or paraesthesia. The two main concerns patients have are the cosmetic appearance of the cysts and the fear of future malignant growth. It has been shown that 58% of cysts will resolve spontaneously over time. Treatment can be either conservative or through surgical excision. This review concluded that nonsurgical treatment is largely ineffective in treating ganglion cysts. However, it advised to patients who do not surgical treatment but would like symptomatic relief. Compared to surgery, which has a lower recurrence rate but have a higher complication rate with longer recovery period. It has been shown that surgical interventions do not provide better symptomatic relief compared to conservative treatment. If symptomatic relief is the patient's primary concern, a conservative approach is preferred, whilst surgical intervention will decrease the likelihood of recurrence. PMID:24967120

  15. Macular Degeneration

    MedlinePlus

    ... common early symptom. Dry AMD happens when the light-sensitive cells in the macula slowly break down. Your gradually lose your central vision. A common early symptom is that straight lines appear crooked. Regular comprehensive eye exams can detect macular degeneration before the disease ...

  16. Retinal ganglion cell axons regenerate in the presence of intact sensory fibres.

    PubMed

    King, Carolyn; Bartlett, Carole; Sauvé, Yves; Lund, Ray; Dunlop, Sarah; Beazley, Lyn

    2006-02-01

    A novel allograft paradigm was used to test whether adult mammalian central axons regenerate within a peripheral nerve environment containing intact sensory axons. Retinal ganglion cell axon regeneration was compared following anastomosis of dorsal root ganglia grafts or conventional peripheral nerve grafts to the adult rat optic nerve. Dorsal root ganglia grafts comprised intact sensory and degenerate motor axons, whereas conventional grafts comprised both degenerating sensory and motor axons. Retinal ganglion cell axons were traced after 2 months. Dorsal root ganglia survived with their axons persisting throughout the graft. Comparable numbers of retinal ganglion cells regenerated axons into both dorsal root ganglia (1053+/-223) and conventional grafts (1323+/-881; P>0.05). The results indicate that an intact sensory environment supports central axon regeneration. PMID:16407770

  17. Temporomandibular Joint Ganglion Cyst: A Unique Case of Complete Resolution Following Subtotal Excision.

    PubMed

    Levarek, Rachel E; Nolan, Patrick J

    2016-09-01

    Ganglion cysts of the temporomandibular joint (TMJ) are a rare entity. Most often, ganglions present in anatomic regions, such as the hand, wrist, knee, foot, or ankle. Ganglion cysts are pseudocysts characterized by a fibrous connective tissue lining that lacks synovial cells and contains a thick gelatinous material. The etiology remains unclear, but might involve myxoid degeneration or softening of the collagen and connective tissue after long-term irritation and trauma. Ganglion cysts of the TMJ most commonly present as a swelling in the preauricular region, produce limited or no pain, and often have no effect on mouth opening. Because of the infrequent involvement of ganglion cysts with the TMJ and the nonspecific clinical presentation, the diagnosis is challenging. Diagnostic imaging tools, such as computed tomography and magnetic resonance imaging, have aided in diagnosis; however, only histopathologic examination will lead to a definitive diagnosis. The precise management of ganglion cysts of the TMJ remains uncertain owing to the uncommon appearance of these lesions. Treatment has focused on surgical excision without regard for lesion size or symptoms. This seems to be due to the decreased rate of recurrence after complete excision and microscopic examination providing the best method for a definitive diagnosis. This report describes a unique case of an 88-year-old woman with a large multilocular ganglion cyst of the right TMJ that completely resolved approximately 1.5 years after subtotal cystectomy. PMID:27019412

  18. Corticobasal degeneration.

    PubMed

    Gibb, W R; Luthert, P J; Marsden, C D

    1989-10-01

    Three patients with clinical and pathological features of corticobasal degeneration are described. They presented with a progressive disease bearing some clinical resemblance to Steele-Richardson-Olszewski syndrome and displaying some pathological features of Pick's disease. Their illness began at the age of 59 to 66 yrs with focal dystonia and myoclonus of an arm, the 'alien hand' sign, or an akinetic-rigid syndrome. They developed a supranuclear gaze palsy, parkinsonian features and mild cerebellar signs. Two patients showed constructional dyspraxia when using the arms. The duration of disease to death was 4 to 6 yrs. Pathological examination showed frontoparietal atrophy with cortical cell loss, gliosis and Pick cells, but there was no significant hippocampal disease or Pick bodies in this region. There was nerve cell loss and gliosis in the thalamus, lentiform nucleus, subthalamic nucleus, red nucleus, midbrain tegmentum, substantia nigra and locus coeruleus. Neuronal inclusions in the substantia nigra, termed corticobasal inclusions, were reminiscent of the globose neurofibrillary tangle of Steele-Richardson-Olszewski syndrome, and other pale inclusions resembled the pale body of Parkinson's disease, but Lewy bodies and neurofibrillary tangles were generally absent. Some nigral inclusions were similar to those in Pick's disease. Despite some pathological similarities to Pick's disease we suggest that the distribution of nerve cell loss and the corticobasal inclusion are unique to corticobasal degeneration. PMID:2478251

  19. Symptomatic Elbow Ganglion Causing Pronator Syndrome

    PubMed Central

    Rockwell, W. Bradford

    2014-01-01

    Summary: Descriptions of ganglion cysts date back to 400 BC. Ganglions causing peripheral nerve compression have been described most notably at the wrist. Ganglion compression of the median nerve at the elbow is rare. We report a case of a palmar elbow ganglion causing median nerve compression and the clinical presentation of pronator syndrome. After removal of the ganglion and median nerve decompression, the patient’s symptoms fully resolved. PMID:25289303

  20. EVALUATION OF HYPERALGESIA AND HISTOLOGICAL CHANGES OF DORSAL ROOT GANGLION INDUCED BY NUCLEUS PULPOSUS

    PubMed Central

    Grava, André Luiz de Souza; Ferrari, Luiz Fernando; Parada, Carlos Amílcar; Defino, Helton Luiz Aparecido

    2015-01-01

    To evaluate the hyperalgesia and histological abnormalities induced by contact between the dorsal root ganglion and the nucleus pulposus. Methods: Twenty Wistar rats were used, divided into two experimental groups. In one of the groups, a fragment of autologous nucleus pulposus was removed from the sacrococcygeal region and deposited on the L5 dorsal root ganglia. In the other group (control), a fragment of adipose tissue was deposited on the L5 dorsal root ganglia. Mechanical and thermal hyperalgesia was evaluated on the third day and the first, third, fifth and seventh weeks after the operation. A L5 dorsal root ganglion was removed in the first, third, fifth and seventh weeks after the operation for histological study using HE staining and histochemical study using specific labeling for iNOS. Results: Higher intensity of mechanical and thermal hyperalgesia was observed in the group of animals in which the nucleus pulposus was placed in contact with the dorsal root ganglion. In this group, the histological study showed abnormalities of the dorsal root ganglion tissue, characterized by an inflammatory process and axonal degeneration. The histopathological abnormalities of the dorsal root ganglion tissue presented increasing intensity with increasing length of observation, and there was a correlation with maintenance of the hyperalgesia observed in the behavioral assessment. Immunohistochemistry using specific labeling for iNOS in the group of animals in which the nucleus pulposus was placed in contact with the dorsal root ganglion showed higher expression of this enzyme in the nuclei of the inflammatory cells (glial cells) surrounding the neurons. Conclusion: Contact between the nucleus pulposus and the dorsal root ganglion induced mechanical and thermal hyperalgesia and caused histological abnormalities in the dorsal root ganglion components. These abnormalities were characterized by an inflammatory and degenerative process in the structures of the dorsal root

  1. Macular degeneration (image)

    MedlinePlus

    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 ...

  2. Optic pathway degeneration in Japanese black cattle

    PubMed Central

    CHIBA, Shiori; FUNATO, Shingo; HORIUCHI, Noriyuki; MATSUMOTO, Kotaro; INOKUMA, Hisashi; FURUOKA, Hidefumi; KOBAYASHI, Yoshiyasu

    2014-01-01

    Degeneration of the optic pathway has been reported in various animal species including cattle. We experienced a case of bilateral optic tract degeneration characterized by severe gliosis in a Japanese black cattle without any obvious visual defects. To evaluate the significance, pathological nature and pathogenesis of the lesions, we examined the optic pathway in 60 cattle (41 Japanese black, 13 Holstein and 6 crossbreed) with or without ocular abnormalities. None of these animals had optic canal stenosis. Degenerative changes with severe gliosis in the optic pathway, which includes the optic nerve, optic chiasm and optic tract, were only observed in 8 Japanese black cattle with or without ocular abnormalities. Furthermore, strong immunoreactivity of glial fibrillary acidic protein was observed in the retinal stratum opticum and ganglion cell layer in all 5 cattle in which the optic pathway lesions could be examined. As etiological research, we also examined whether the concentrations of vitamin A and vitamin B12 or bovine viral diarrhea virus (BVDV) infection was associated with optic pathway degeneration. However, our results suggested that the observed optic pathway degeneration was probably not caused by these factors. These facts indicate the presence of optic pathway degeneration characterized by severe gliosis that has never been reported in cattle without bilateral compressive lesions in the optic pathway or bilateral severe retinal atrophy. PMID:25421501

  3. Ganglion Cyst of the Wrist and Hand

    MedlinePlus

    ... frequently fails to eliminate the ganglion because the “root” or connection to the joint or tendon sheath ... a weed which will grow back if the root is not removed. In many cases, the ganglion ...

  4. Occult scapholunate ganglion: a cause of dorsal radial wrist pain.

    PubMed

    Steinberg, B D; Kleinman, W B

    1999-03-01

    There are multiple causes for chronic dorsal wrist pain over the scapholunate ligament, including occult dorsal carpal ganglion cyst, scaphoid impaction syndrome, dorsal carpal capsulitis, distal posterior interosseous nerve syndrome, and dynamic scapholunate ligament instability. Patients with such pain often have normal x-rays. A retrospective study of 21 patients undergoing surgical exploration for chronic dorsal radial wrist pain who had no palpable cyst and normal x-rays revealed that 18 of the patients had occult scapholunate ganglion cysts or myxomatous degeneration within the scapholunate ligament. All had failed long-term conservative management. Surgery involved an approach through Langer's lines, resection of a large triangular portion of the capsule between the dorsal intercarpal and radiotriquetral ligaments, and tangential debridement of the area of myxoid degeneration proximal to the distal 2 to 3 mm of dorsal scapholunate interosseous ligament. None of the patients had scapholunate instability or scaphoid impacting syndrome. Of the 18 patients with histologically confirmed myxomatous changes in the scapholunate ligament, 16 had an excellent outcome as defined by rigorous criteria; 1 had a good outcome. There was 1 patient with a poor result. A compelling argument is made for surgical exploration of the scapholunate joint in patients with persistent dorsal radial wrist pain and scapholunate point tenderness. PMID:10194003

  5. Reinnervation of Hair Cells by Auditory Neurons after Selective Removal of Spiral Ganglion Neurons

    PubMed Central

    Martinez-Monedero, Rodrigo; Corrales, C. Eduardo; Cuajungco, Math P.; Heller, Stefan; Edge, Albert S.B.

    2007-01-01

    Hearing loss can be caused by primary degeneration of spiral ganglion neurons or by secondary degeneration of these neurons after hair cell loss. The replacement of auditory neurons would be an important step in any attempt to restore auditory function in patients with damaged inner ear neurons or hair cells. Application of β-bungarotoxin, a toxin derived from snake venom, to an explant of the cochlea eradicates spiral ganglion neurons while sparing the other cochlear cell types. The toxin was found to bind to the neurons and to cause apoptotic cell death without affecting hair cells or other inner ear cell types as indicated by TUNEL staining, and, thus, the toxin provides a highly specific means of deafferentation of hair cells. We therefore used the denervated organ of Corti for the study of neuronal regeneration and synaptogenesis with hair cells and found that spiral ganglion neurons obtained from the cochlea of an untreated newborn mouse reinnervated hair cells in the toxin-treated organ of Corti and expressed synaptic vesicle markers at points of contact with hair cells. These findings suggest that it may be possible to replace degenerated neurons by grafting new cells into the organ of Corti. PMID:16408287

  6. Macular Degeneration: An Overview.

    ERIC Educational Resources Information Center

    Chalifoux, L. M.

    1991-01-01

    This article presents information on macular degeneration for professionals helping persons with this disease adjust to their visual loss. It covers types of macular degeneration, the etiology of the disease, and its treatment. Also considered are psychosocial problems and other difficulties that persons with age-related macular degeneration face.…

  7. The role of autophagy in axonal degeneration of the optic nerve.

    PubMed

    Koch, Jan Christoph; Lingor, Paul

    2016-03-01

    Different pathological conditions including glaucoma, optic neuritis, hereditary optic atrophy and traumatic injury lead to a degeneration of retinal ganglion cell axons in the optic nerve. Besides this clinical relevance, several experimental models employ the optic nerve as a model system to examine general mechanisms of axonal degeneration in the central nervous system. Several experimental studies have demonstrated that an activation of autophagy is a prominent feature of axonal degeneration in the optic nerve independent of the underlying pathological condition. However, the function of autophagy in axonal degeneration remains still unclear. Inhibition of autophagy was found to attenuate axonal degeneration within the first hours after optic nerve lesion. Other studies focusing on survival of retinal ganglion cells at later postlesional time points report contradicting results, where both inhibition and induction of autophagy were beneficial for survival, depending on the model system or examination time. Therefore, a more precise understanding of the role and the kinetics of autophagy in axonal degeneration is mandatory to develop new therapies for diseases of the optic nerve. Here, we review the literature on the pathophysiological role of autophagy in axonal degeneration in the optic nerve and discuss its implications for future therapeutic approaches in diseases of the eye and the central nervous system involving axonal degeneration. PMID:26315785

  8. Proximal Sciatic Nerve Intraneural Ganglion Cyst

    PubMed Central

    Swartz, Karin R.; Wilson, Dianne; Boland, Michael; Fee, Dominic B.

    2009-01-01

    Intraneural ganglion cysts are nonneoplastic, mucinous cysts within the epineurium of peripheral nerves which usually involve the peroneal nerve at the knee. A 37-year-old female presented with progressive left buttock and posterior thigh pain. Magnetic resonance imaging revealed a sciatic nerve mass at the sacral notch which was subsequently revealed to be an intraneural ganglion cyst. An intraneural ganglion cyst confined to the proximal sciatic nerve has only been reported once prior to 2009. PMID:20069041

  9. Ligamentous Hyperlaxity and Dorsal Wrist Ganglions

    PubMed Central

    McKeon, Kathleen E.; London, Daniel A.; Osei, Daniel A.; Gelberman, Richard H.; Goldfarb, Charles A.; Boyer, Martin I.; Calfee, Ryan P.

    2014-01-01

    Purpose To determine if symptomatic dorsal wrist ganglions are associated with generalized ligamentous hyperlaxity. Methods Ninety-six patients (61 females) presenting to hand surgeons for a symptomatic dorsal wrist ganglions were prospectively enrolled in this case-control investigation. Beighton scores were calculated to quantify generalized ligamentous laxity in each patient, and a scaphoid shift test (scapholunate capsuloligamentous laxity evaluation) was performed. A positive scaphoid shift test was defined by both pain and a palpable clunk. Ninety-six individuals without ganglions were then enrolled to form an age and sex frequency-matched control cohort. The control group was similarly assessed for Beighton score and scaphoid shift test. Binary logistic regression was performed to assess the association of ganglions with generalized ligamentous hyperlaxity (Beighton score ≥4) while accounting for effects of age and sex. Results Patients with symptomatic dorsal wrist ganglions demonstrated significantly increased rates of generalized ligamentous hyperlaxity. Among those with ganglions, 27 of 96 (28%) patients exhibited generalized ligamentous hyperlaxity, compared to 12 of the 96 (13%) age and sex-matched individuals in the control group. Patients with symptomatic dorsal wrist ganglions were also significantly more likely to demonstrate localized scapholunate hyperlaxity with a positive scaphoid shift test (25% positive scaphoid shift test with ganglions vs 1% in controls). In logistic modeling, patients with dorsal wrist ganglions had 2.9 (95% CI 1.3-6.2) times greater odds of generalized ligamentous hyperlaxity compared to patients without a dorsal wrist ganglion after accounting for patient age and sex. Discussion Symptomatic dorsal wrist ganglions were associated with both generalized ligamentous hyperlaxity and a positive scaphoid shift test. Although an association between wrist ganglions and ligamentous hyperlaxity does not prove causation, the

  10. Restoring visual function to blind mice with a photoswitch that exploits electrophysiological remodeling of retinal ganglion cells

    PubMed Central

    Tochitsky, Ivan; Polosukhina, Aleksandra; Degtyar, Vadim E.; Gallerani, Nicholas; Smith, Caleb M.; Friedman, Aaron; Van Gelder, Russell N.; Trauner, Dirk; Kaufer, Daniela; Kramer, Richard H.

    2014-01-01

    Summary Retinitis pigmentosa (RP) and age-related macular degeneration (AMD) are blinding diseases caused by the degeneration of rods and cones, leaving the remainder of the visual system unable to respond to light. Here we report a chemical photoswitch named DENAQ that restores retinal responses to white light of intensity similar to ordinary daylight. A single intraocular injection of DENAQ photosensitizes the blind retina for days, restoring electrophysiological and behavioral responses with no toxicity. Experiments on mouse strains with functional, non-functional, or degenerated rods and cones show that DENAQ is effective only in retinas with degenerated photoreceptors. DENAQ confers light sensitivity on a hyperpolarization-activated inward current that is enhanced in degenerated retina, enabling optical control of retinal ganglion cell firing The acceptable light sensitivity, favorable spectral sensitivity, and selective targeting to diseased tissue make DENAQ a prime drug candidate for vision restoration in patients with end-stage RP and AMD. PMID:24559673

  11. Restoring visual function to blind mice with a photoswitch that exploits electrophysiological remodeling of retinal ganglion cells.

    PubMed

    Tochitsky, Ivan; Polosukhina, Aleksandra; Degtyar, Vadim E; Gallerani, Nicholas; Smith, Caleb M; Friedman, Aaron; Van Gelder, Russell N; Trauner, Dirk; Kaufer, Daniela; Kramer, Richard H

    2014-02-19

    Retinitis pigmentosa (RP) and age-related macular degeneration (AMD) are blinding diseases caused by the degeneration of rods and cones, leaving the remainder of the visual system unable to respond to light. Here, we report a chemical photoswitch named DENAQ that restores retinal responses to white light of intensity similar to ordinary daylight. A single intraocular injection of DENAQ photosensitizes the blind retina for days, restoring electrophysiological and behavioral responses with no toxicity. Experiments on mouse strains with functional, nonfunctional, or degenerated rods and cones show that DENAQ is effective only in retinas with degenerated photoreceptors. DENAQ confers light sensitivity on a hyperpolarization-activated inward current that is enhanced in degenerated retina, enabling optical control of retinal ganglion cell firing. The acceptable light sensitivity, favorable spectral sensitivity, and selective targeting to diseased tissue make DENAQ a prime drug candidate for vision restoration in patients with end-stage RP and AMD. PMID:24559673

  12. Ganglions of the proximal interphalangeal joint.

    PubMed

    Cheng, C A; Rockwell, W B

    1999-08-01

    Ganglion cysts-the most common hand tumors-usually affect women in their twenties and thirties. The cause of these cysts is unknown, although trauma has been postulated as an inciting factor. Ganglions occur most commonly at the dorsal and palmar wrist. However, ganglions of the proximal interphalangeal (PIP) joint are rare. Four patients with PIP joint ganglions were recently treated at our institution. Three received aspiration and one received operative therapy, all with good results. All four patients were older than 65 years. PMID:10470671

  13. Effects of low level laser treatment on the survival of axotomized retinal ganglion cells in adult Hamsters.

    PubMed

    So, Kwok-Fai; Leung, Mason Chin Pang; Cui, Qi

    2014-11-01

    Injury to axons close to the neuronal bodies in the mammalian central nervous system causes a large proportion of parenting neurons to degenerate. It is known that optic nerve transection close to the eye in rodents leads to a loss of about half of retinal ganglion cells in 1 week and about 90% in 2 weeks. Using low level laser treatment in the present study, we demonstrated that treatment with helium-neon (660 nm) laser with 15 mW power could delay retinal ganglion cell death after optic nerve axotomy in adult hamsters. The effect was most apparent in the first week with a short period of treatment time (5 minutes) in which 65-66% of retinal ganglion cells survived the optic nerve axotomy whereas 45-47% of retinal ganglion cells did so in optic nerve axotomy controls. We also found that single dose and early commencement of laser irradiation were important in protecting retinal ganglion cells following optic nerve axotomy. These findings thus convincingly show that appropriate laser treatment may be neuroprotective to retinal ganglion cells. PMID:25558230

  14. Effects of low level laser treatment on the survival of axotomized retinal ganglion cells in adult Hamsters

    PubMed Central

    So, Kwok-Fai; Leung, Mason Chin Pang; Cui, Qi

    2014-01-01

    Injury to axons close to the neuronal bodies in the mammalian central nervous system causes a large proportion of parenting neurons to degenerate. It is known that optic nerve transection close to the eye in rodents leads to a loss of about half of retinal ganglion cells in 1 week and about 90% in 2 weeks. Using low level laser treatment in the present study, we demonstrated that treatment with helium-neon (660 nm) laser with 15 mW power could delay retinal ganglion cell death after optic nerve axotomy in adult hamsters. The effect was most apparent in the first week with a short period of treatment time (5 minutes) in which 65–66% of retinal ganglion cells survived the optic nerve axotomy whereas 45–47% of retinal ganglion cells did so in optic nerve axotomy controls. We also found that single dose and early commencement of laser irradiation were important in protecting retinal ganglion cells following optic nerve axotomy. These findings thus convincingly show that appropriate laser treatment may be neuroprotective to retinal ganglion cells. PMID:25558230

  15. Focal expression of mutant huntingtin in the songbird basal ganglia disrupts cortico-basal ganglia networks and vocal sequences.

    PubMed

    Tanaka, Masashi; Singh Alvarado, Jonnathan; Murugan, Malavika; Mooney, Richard

    2016-03-22

    The basal ganglia (BG) promote complex sequential movements by helping to select elementary motor gestures appropriate to a given behavioral context. Indeed, Huntington's disease (HD), which causes striatal atrophy in the BG, is characterized by hyperkinesia and chorea. How striatal cell loss alters activity in the BG and downstream motor cortical regions to cause these disorganized movements remains unknown. Here, we show that expressing the genetic mutation that causes HD in a song-related region of the songbird BG destabilizes syllable sequences and increases overall vocal activity, but leave the structure of individual syllables intact. These behavioral changes are paralleled by the selective loss of striatal neurons and reduction of inhibitory synapses on pallidal neurons that serve as the BG output. Chronic recordings in singing birds revealed disrupted temporal patterns of activity in pallidal neurons and downstream cortical neurons. Moreover, reversible inactivation of the cortical neurons rescued the disorganized vocal sequences in transfected birds. These findings shed light on a key role of temporal patterns of cortico-BG activity in the regulation of complex motor sequences and show how a genetic mutation alters cortico-BG networks to cause disorganized movements. PMID:26951661

  16. Focal expression of mutant huntingtin in the songbird basal ganglia disrupts cortico-basal ganglia networks and vocal sequences

    PubMed Central

    Tanaka, Masashi; Singh Alvarado, Jonnathan; Murugan, Malavika; Mooney, Richard

    2016-01-01

    The basal ganglia (BG) promote complex sequential movements by helping to select elementary motor gestures appropriate to a given behavioral context. Indeed, Huntington’s disease (HD), which causes striatal atrophy in the BG, is characterized by hyperkinesia and chorea. How striatal cell loss alters activity in the BG and downstream motor cortical regions to cause these disorganized movements remains unknown. Here, we show that expressing the genetic mutation that causes HD in a song-related region of the songbird BG destabilizes syllable sequences and increases overall vocal activity, but leave the structure of individual syllables intact. These behavioral changes are paralleled by the selective loss of striatal neurons and reduction of inhibitory synapses on pallidal neurons that serve as the BG output. Chronic recordings in singing birds revealed disrupted temporal patterns of activity in pallidal neurons and downstream cortical neurons. Moreover, reversible inactivation of the cortical neurons rescued the disorganized vocal sequences in transfected birds. These findings shed light on a key role of temporal patterns of cortico-BG activity in the regulation of complex motor sequences and show how a genetic mutation alters cortico-BG networks to cause disorganized movements. PMID:26951661

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

    PubMed

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

    1987-05-01

    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. PMID:3584559

  18. Tissue engineering the retinal ganglion cell nerve fiber layer.

    PubMed

    Kador, Karl E; Montero, Ramon B; Venugopalan, Praseeda; Hertz, Jonathan; Zindell, Allison N; Valenzuela, Daniel A; Uddin, Mohammed S; Lavik, Erin B; Muller, Kenneth J; Andreopoulos, Fotios M; Goldberg, Jeffrey L

    2013-06-01

    Retinal degenerative diseases, such as glaucoma and macular degeneration, affect millions of people worldwide and ultimately lead to retinal cell death and blindness. Cell transplantation therapies for photoreceptors demonstrate integration and restoration of function, but transplantation into the ganglion cell layer is more complex, requiring guidance of axons from transplanted cells to the optic nerve head in order to reach targets in the brain. Here we create a biodegradable electrospun (ES) scaffold designed to direct the growth of retinal ganglion cell (RGC) axons radially, mimicking axon orientation in the retina. Using this scaffold we observed an increase in RGC survival and no significant change in their electrophysiological properties. When analyzed for alignment, 81% of RGCs were observed to project axons radially along the scaffold fibers, with no difference in alignment compared to the nerve fiber layer of retinal explants. When transplanted onto retinal explants, RGCs on ES scaffolds followed the radial pattern of the host retinal nerve fibers, whereas RGCs transplanted directly grew axons in a random pattern. Thus, the use of this scaffold as a cell delivery device represents a significant step towards the use of cell transplant therapies for the treatment of glaucoma and other retinal degenerative diseases. PMID:23489919

  19. Tissue Engineering the Retinal Ganglion Cell Nerve Fiber Layer

    PubMed Central

    Kador, Karl E.; Montero, Ramon B.; Venugopalan, Praseeda; Hertz, Jonathan; Zindell, Allison N.; Valenzuela, Daniel A.; Uddin, Mohammed S.; Lavik, Erin B.; Muller, Kenneth J.; Andreopoulos, Fotios M.; Goldberg, Jeffrey L.

    2013-01-01

    Retinal degenerative diseases, such as glaucoma and macular degeneration, affect millions of people worldwide and ultimately lead to retinal cell death and blindness. Cell transplantation therapies for photoreceptors demonstrate integration and restoration of function, but transplantation into the ganglion cell layer is more complex, requiring guidance of axons from transplanted cells to the optic nerve head in order to reach targets in the brain. Here we create a biodegradable electrospun (ES) scaffold designed to direct the growth of retinal ganglion cell (RGC) axons radially, mimicking axon orientation in the retina. Using this scaffold we observed an increase in RGC survival and no significant change in their electrophysiological properties. When analyzed for alignment, 81% of RGCs were observed to project axons radially along the scaffold fibers, with no difference in alignment compared to the nerve fiber layer of retinal explants. When transplanted onto retinal explants, RGCs on ES scaffolds followed the radial pattern of the host retinal nerve fibers, whereas RGCs transplanted directly grew axons in a random pattern. Thus, the use of this scaffold as a cell delivery device represents a significant step towards the use of cell transplant therapies for the treatment of glaucoma and other retinal degenerative diseases. PMID:23489919

  20. Effects of metal ions on fibroblasts and spiral ganglion cells.

    PubMed

    Paasche, G; Ceschi, P; Löbler, M; Rösl, C; Gomes, P; Hahn, A; Rohm, H W; Sternberg, K; Lenarz, T; Schmitz, K-P; Barcikowski, S; Stöver, T

    2011-04-01

    Degeneration of spiral ganglion cells (SGC) after deafness and fibrous tissue growth around the electrode carrier after cochlear implantation are two of the major challenges in current cochlear implant research. Metal ions are known to possess antimicrobial and antiproliferative potential. The use of metal ions could therefore provide a way to reduce tissue growth around the electrode array after cochlear implantation. Here, we report on in vitro experiments with different concentrations of metal salts with antiproliferative and toxic effects on fibroblasts, PC-12 cells, and freshly isolated spiral ganglion cells, the target cells for electrical stimulation by a cochlear implant. Standard cell lines (NIH/3T3 and L-929 fibroblasts and PC-12 cells) and freshly isolated SGC were incubated with concentrations of metal ions between 0.3 μmol/liter and 10 mmol/liter for 48 hr. Cell survival was investigated by neutral red uptake, CellQuantiBlue assay, or counting of stained surviving neurons. Silver ions exhibited distinct thresholds for proliferating and confluent cells. For zinc ions, the effective concentration was lower for fibroblasts than for PC-12 cells. SGC showed comparable thresholds for reduced cell survival not only for silver and zinc ions but also for copper(II) ions, indicating that these ions might be promising for reducing tissue growth on the surface of CI electrode arrays. These effects were also observed when combinations of two of these ions were investigated. PMID:21312225

  1. N -methyl- N -nitrosourea-induced retinal degeneration in mice.

    PubMed

    Chen, Yuan-Yuan; Liu, Shi-Liang; Hu, Dan-Ping; Xing, Yi-Qiao; Shen, Yin

    2014-04-01

    Mouse retinal degeneration models have been investigated for many years in the hope of understanding the mechanism of photoreceptor cell death. N -methyl- N -nitrosourea (MNU) has been previously shown to induce outer retinal degeneration in mice. After MNU was intraperitoneally injected in C57/BL mice, we observed a gradual decrease in the outer nuclear layer (ONL) thickness associated with photoreceptor outer segment loss, bipolar cell dendritic retraction and reactive gliosis. Reactive gliosis was confirmed by increased GFAP protein levels. More serious damage to the central retina as opposed to the peripheral retina was found in the MNU-induced retinal degeneration model. Retinal ganglion cells (RGC) appear to be spared for at least two months after MNU treatment. Following retinal vessel labelling, we observed vascular complexes in the distal vessels, indicating retinal vessel damage. In the remnant retinal photoreceptor of the MNU-treated mouse, concentrated colouring nuclei were detected by electron microscopy, together with the loss of mitochondria and displaced remnant synaptic ribbons in the photoreceptor. We also observed decreased mitochondrial protein levels and increased amounts of nitrosylation/nitration in the photoreceptors. The mechanism of MNU-induced apoptosis may result from oxidative stress or the loss of retinal blood supply. MNU-induced mouse retinal degeneration in the outer retina is a useful animal model for photoreceptor degeneration diseases, such as age-related macular degeneration (AMD) and retinitis pigmentosa (RP). PMID:24509257

  2. Development of Animal Models of Local Retinal Degeneration

    PubMed Central

    Lorach, Henri; Kung, Jennifer; Beier, Corinne; Mandel, Yossi; Dalal, Roopa; Huie, Philip; Wang, Jenny; Lee, Seungjun; Sher, Alexander; Jones, Bryan William; Palanker, Daniel

    2015-01-01

    Purpose Development of nongenetic animal models of local retinal degeneration is essential for studies of retinal pathologies, such as chronic retinal detachment or age-related macular degeneration. We present two different methods to induce a highly localized retinal degeneration with precise onset time, that can be applied to a broad range of species in laboratory use. Methods A 30-μm thin polymer sheet was implanted subretinally in wild-type (WT) rats. The effects of chronic retinal separation from the RPE were studied using histology and immunohistochemistry. Another approach is applicable to species with avascular retina, such as rabbits, where the photoreceptors and RPE were thermally ablated over large areas, using a high power scanning laser. Results Photoreceptors above the subretinal implant in rats degenerated over time, with 80% of the outer nuclear layer disappearing within a month, and the rest by 3 months. Similar loss was obtained by selective photocoagulation with a scanning laser. Cells in the inner nuclear layer and ganglion cell layer were preserved in both cases. However, there were signs of rewiring and decrease in the size of the bipolar cell terminals in the damaged areas. Conclusions Both methods induce highly reproducible degeneration of photoreceptors over a defined area, with complete preservation of the inner retinal neurons during the 3-month follow-up. They provide a reliable platform for studies of local retinal degeneration and development of therapeutic strategies in a wide variety of species. PMID:26207299

  3. Intrinsically photosensitive retinal ganglion cells.

    PubMed

    Do, Michael Tri Hoang; Yau, King-Wai

    2010-10-01

    Life on earth is subject to alternating cycles of day and night imposed by the rotation of the earth. Consequently, living things have evolved photodetective systems to synchronize their physiology and behavior with the external light-dark cycle. This form of photodetection is unlike the familiar "image vision," in that the basic information is light or darkness over time, independent of spatial patterns. "Nonimage" vision is probably far more ancient than image vision and is widespread in living species. For mammals, it has long been assumed that the photoreceptors for nonimage vision are also the textbook rods and cones. However, recent years have witnessed the discovery of a small population of retinal ganglion cells in the mammalian eye that express a unique visual pigment called melanopsin. These ganglion cells are intrinsically photosensitive and drive a variety of nonimage visual functions. In addition to being photoreceptors themselves, they also constitute the major conduit for rod and cone signals to the brain for nonimage visual functions such as circadian photoentrainment and the pupillary light reflex. Here we review what is known about these novel mammalian photoreceptors. PMID:20959623

  4. Ultrasound-guided aspiration and steroid injection of a posterior cruciate ligament ganglion cyst: report of a case.

    PubMed

    Vilella, Giuseppe Maria; Guerrisi, Pietro; Lucignani, Giulia; Pasquali, Gaia; Drudi, Francesco Maria

    2015-09-01

    Ganglion cysts are benign masses that originate from mucinous degeneration of the connective tissues and are quite rare when arising from the knee joint. Symptoms are often represented by pain, joint tenderness, effusion and occasional swelling with a palpable mass in the popliteal region of the knee. Percutaneous aspiration followed by a corticosteroid injection of a ganglion cyst has either a diagnostic or therapeutic meaning and its guidance through ultrasound allows the operator to make more accurate the procedure, ensuring the correct placement of the needle inside the lesion. We report our experience in the treatment of a voluminous ganglion cyst of the posterior cruciate ligament performed through the ultrasound guidance in a symptomatic young patient. PMID:26261469

  5. Dorsal wrist ganglion: Current review of literature.

    PubMed

    Meena, Sanjay; Gupta, Ajay

    2014-06-01

    Ganglion cyst is the most common soft tissue tumour of hand. Sixty to seventy percent of ganglion cysts are found in the dorsal aspect of the wrist. They may affect any age group; however they are more common in the twenties to forties. Its origin and pathogenesis remains enigmatic. Non-surgical treatment is unreliable with a high recurrence rates. Open surgical excision leads to unsightly scar and poor outcome. Arthroscopy excision has shown very promising result with very low recurrence rate. We reviewed the current literature available on dorsal wrist ganglion. PMID:25983472

  6. Intramuscular Ganglion of the Quadriceps Femoris

    PubMed Central

    Kim, Yeung Jin; Chae, Soo Uk; Kim, Jong Yun; Jo, Hyang Jeong

    2013-01-01

    Ganglion cysts are common lesions that are most often found around the joints of the hands and feet. Ganglia around the distal femur usually occur within the synovial membrane or tendon sheath, but rarely within muscles. Several cases of intramuscular ganglions in the hand and wrist have been reported, but a ganglion cyst in the quadriceps muscle has rarely been addressed in studies. In this report, we present a 17-year-old patient with a painful movable mass in the intramuscular area of the quadriceps femoris that was diagnosed by ultrasound and treated by excision and biopsy. PMID:23508475

  7. Dorsal wrist ganglion: Current review of literature

    PubMed Central

    Meena, Sanjay; Gupta, Ajay

    2014-01-01

    Ganglion cyst is the most common soft tissue tumour of hand. Sixty to seventy percent of ganglion cysts are found in the dorsal aspect of the wrist. They may affect any age group; however they are more common in the twenties to forties. Its origin and pathogenesis remains enigmatic. Non-surgical treatment is unreliable with a high recurrence rates. Open surgical excision leads to unsightly scar and poor outcome. Arthroscopy excision has shown very promising result with very low recurrence rate. We reviewed the current literature available on dorsal wrist ganglion. PMID:25983472

  8. Intervertebral Disc Degeneration

    PubMed Central

    Rannou, François; Lee, Tzong-Shyuan; Zhou, Rui-Hai; Chin, Jennie; Lotz, Jeffrey C.; Mayoux-Benhamou, Marie-Anne; Barbet, Jacques Patrick; Chevrot, Alain; Shyy, John Y.-J.

    2004-01-01

    Degeneration of the intervertebral disk (IVD) is a major pathological process implicated in low back pain and is a prerequisite to disk herniation. Although mechanical stress is an important modulator of the degeneration, the underlying molecular mechanism remains unclear. The association of human IVD degeneration, assessed by magnetic resonance imaging, with annulus fibrosus cell apoptosis and anti-cytochrome c staining revealed that the activation of the mitochondria-dependent apoptosome was a major event in the degeneration process. Mouse models of IVD degeneration were used to investigate the role of the mechanical stress in this process. The application of mechanical overload (1.3 MPa) for 24 hours induced annulus fibrosus cell apoptosis and led to severe degeneration of the mouse disks. Immunostaining revealed cytochrome c release but not Fas-L generation. The role of the caspase-9-dependent mitochondrial pathway in annulus fibrosus cell apoptosis induced by overload was investigated further with the use of cultured rabbit IVD cells in a stretch device. Mechanical overload (15% area change) induced apoptosis with increased caspase-9 activity and decreased mitochondrial membrane potential. Furthermore, Z-LEHD-FMK, a caspase-9 inhibitor, but not Z-IETD-FMK, a caspase-8 inhibitor, attenuated the overload-induced apoptosis. Our results from human samples, mouse models, and annulus fibrosus culture experiments demonstrate that the mechanical overload-induced IVD degeneration is mediated through the mitochondrial apoptotic pathway in IVD cells. PMID:14982845

  9. Molecular biology of retinal ganglion cells.

    PubMed Central

    Xiang, M; Zhou, H; Nathans, J

    1996-01-01

    Retinal ganglion cells are the output neurons that encode and transmit information from the eye to the brain. Their diverse physiologic and anatomic properties have been intensively studied and appear to account well for a number of psychophysical phenomena such as lateral inhibition and chromatic opponency. In this paper, we summarize our current view of retinal ganglion cell properties and pose a number of questions regarding underlying molecular mechanisms. As an example of one approach to understanding molecular mechanisms, we describe recent work on several POU domain transcription factors that are expressed in subsets of retinal ganglion cells and that appear to be involved in ganglion cell development. Images Fig. 1 Fig. 2 Fig. 4 Fig. 5 Fig. 6 PMID:8570601

  10. Infraspinatus paralysis due to spinoglenoid notch ganglion.

    PubMed

    Skirving, A P; Kozak, T K; Davis, S J

    1994-07-01

    We describe five patients, seen since 1984, with posterior shoulder pain and isolated wasting and weakness of the infraspinatus. In four of these a ganglion in the spinoglenoid notch was demonstrated by MRI and in one recent case ultrasound scans were positive. Three patients have been treated by operation, but there was recurrence in one after five years. In each confirmed case, the ganglion straddled the base of the spine of the scapula, extending into both supraspinatus and infraspinatus fossae. The nerve was either compressed against the spine or stretched over the posterior aspect of the ganglion. Adequate surgical exposure is essential to preserve the nerve to the infraspinatus and to allow complete removal of the ganglion. This is difficult because of the location and thin-walled nature of the cysts. PMID:8027146

  11. NAD(+) and axon degeneration revisited: Nmnat1 cannot substitute for Wld(S) to delay Wallerian degeneration.

    PubMed

    Conforti, L; Fang, G; Beirowski, B; Wang, M S; Sorci, L; Asress, S; Adalbert, R; Silva, A; Bridge, K; Huang, X P; Magni, G; Glass, J D; Coleman, M P

    2007-01-01

    The slow Wallerian degeneration protein (Wld(S)), a fusion protein incorporating full-length nicotinamide mononucleotide adenylyltransferase 1 (Nmnat1), delays axon degeneration caused by injury, toxins and genetic mutation. Nmnat1 overexpression is reported to protect axons in vitro, but its effect in vivo and its potency remain unclear. We generated Nmnat1-overexpressing transgenic mice whose Nmnat activities closely match that of Wld(S) mice. Nmnat1 overexpression in five lines of transgenic mice failed to delay Wallerian degeneration in transected sciatic nerves in contrast to Wld(S) mice where nearly all axons were protected. Transected neurites in Nmnat1 transgenic dorsal root ganglion explant cultures also degenerated rapidly. The delay in vincristine-induced neurite degeneration following lentiviral overexpression of Nmnat1 was significantly less potent than for Wld(S), and lentiviral overexpressed enzyme-dead Wld(S) still displayed residual neurite protection. Thus, Nmnat1 is significantly weaker than Wld(S) at protecting axons against traumatic or toxic injury in vitro, and has no detectable effect in vivo. The full protective effect of Wld(S) requires more N-terminal sequences of the protein. PMID:16645633

  12. Double Degenerate Binary Systems

    SciTech Connect

    Yakut, K.

    2011-09-21

    In this study, angular momentum loss via gravitational radiation in double degenerate binary (DDB)systems (NS + NS, NS + WD, WD + WD, and AM CVn) is studied. Energy loss by gravitational waves has been estimated for each type of systems.

  13. Biomechanics of Disc Degeneration

    PubMed Central

    Palepu, V.; Kodigudla, M.; Goel, V. K.

    2012-01-01

    Disc degeneration and associated disorders are among the most debated topics in the orthopedic literature over the past few decades. These may be attributed to interrelated mechanical, biochemical, and environmental factors. The treatment options vary from conservative approaches to surgery, depending on the severity of degeneration and response to conservative therapies. Spinal fusion is considered to be the “gold standard” in surgical methods till date. However, the association of adjacent level degeneration has led to the evolution of motion preservation technologies like spinal arthroplasty and posterior dynamic stabilization systems. These new technologies are aimed to address pain and preserve motion while maintaining a proper load sharing among various spinal elements. This paper provides an elaborative biomechanical review of the technologies aimed to address the disc degeneration and reiterates the point that biomechanical efficacy followed by long-term clinical success will allow these nonfusion technologies as alternatives to fusion, at least in certain patient population. PMID:22745914

  14. Ganglions of the hand and wrist.

    PubMed

    Young, L; Bartell, T; Logan, S E

    1988-06-01

    The ganglion is the most common soft tissue tumor of the hand and wrist, originating from the joint capsule or tendon sheath. Accurate diagnosis and proper treatment of these entities require a thorough knowledge of the anatomy of the wrist and hand as well as of the ganglion itself. Definitive therapy is based on total surgical removal of the cyst and its connections to the joint or tendon sheath. PMID:3287641

  15. Anterior Displacement of the Geniculate Ganglion.

    PubMed

    Tachibana, Tomoyasu; Orita, Yorihisa; Nishizaki, Kazunori

    2016-04-01

    We present the case of a 34-year-old Japanese woman with cholesteatoma of the middle ear. During the operation, this patient showed an unusual position of the geniculate ganglion. We reviewed the computed tomography (CT) images targeting the ear of the present case after the operation. We found that the shortest ranges from the ampullated end of the superior semicircular canal to the geniculate ganglion fossa were 5.1 mm on both sides. We did not find any cases with obvious dislocation of the geniculate ganglion among the 67 cases for which we had performed tympanoplasty. Displacement of the geniculate ganglion is either extremely rare or typically unnoticed because this abnormality is asymptomatic. We speculated that the unusual position of the geniculate ganglion was due to an incomplete development of the tympanic tegmen. When surgical treatment such as decompression of the facial nerve or tympanoplasty is performed, close attention should always be paid to the anatomy of the facial nerve from the labyrinthine segment to the geniculate ganglion. In the present case, although connective tissues existed around the anterior epitympanic recess, we left this lesion to avoid iatrogenic facial palsy. PMID:27340996

  16. CRYSTALLINS IN RETINAL GANGLION CELL SURVIVAL AND REGENERATION

    PubMed Central

    Piri, Natik; Kwong, Jacky MK; Caprioli, Joseph

    2013-01-01

    Crystallins are heterogeneous proteins classified into alpha, beta, and gamma families. Although crystallins were first identified as the major structural components of the ocular lens with a principal function to maintain lens transparency, further studies have demonstrated the expression of these proteins in a wide variety of tissues and cell types. Alpha crystallins (alpha A and alpha B) share significant homology with small heat shock proteins and have chaperone-like properties, including the ability to bind and prevent the precipitation of denatured proteins and to increase cellular resistance to stress-induced apoptosis. Stress-induced upregulation of crystallin expression is a commonly observed phenomenon and viewed as a cellular response mechanism against environmental and metabolic insults. However, several studies reported downregulation of crystallin gene expression in various models of glaucomatous nerodegeneration suggesting that that the decreased levels of crystallins may affect the survival properties of retinal ganglion cells and thus, be associated with their degeneration. This hypothesis was corroborated by increased survival of axotomized retinal ganglion cells (RGCs) in retinas overexpressing alpha A or alpha B crystallins. In addition to RGC protective functions of alpha crystallins, beta or gamma crystallins were implicated in RGC axonal regeneration. These findings demonstrate the importance of crystallin genes in RGC survival and regeneration and further in-depth studies are necessary to better understand the mechanisms underlying the functions of these proteins in healthy RGCs as well as during glaucomatous neurodegeneration, which in turn could help in designing new therapeutic strategies to preserve or regenerate these cells. PMID:23709342

  17. Block of gap junctions eliminates aberrant activity and restores light responses during retinal degeneration.

    PubMed

    Toychiev, Abduqodir H; Ivanova, Elena; Yee, Christopher W; Sagdullaev, Botir T

    2013-08-28

    Retinal degeneration leads to progressive photoreceptor cell death, resulting in vision loss. Subsequently, inner retinal neurons develop aberrant synaptic activity, compounding visual impairment. In retinal ganglion cells, light responses driven by surviving photoreceptors are obscured by elevated levels of aberrant spiking activity. Here, we demonstrate in rd10 mice that targeting disruptive neuronal circuitry with a gap junction antagonist can significantly reduce excessive spiking. This treatment increases the sensitivity of the degenerated retina to light stimuli driven by residual photoreceptors. Additionally, this enhances signal transmission from inner retinal neurons to ganglion cells, potentially allowing the retinal network to preserve the fidelity of signals either from prosthetic electronic devices, or from cells optogenetically modified to transduce light. Thus, targeting maladaptive changes to the retina allows for treatments to use existing neuronal tissue to restore light sensitivity, and to augment existing strategies to replace lost photoreceptors. PMID:23986234

  18. Relationship between dorsal ganglion cysts of the wrist and intraosseous ganglion cysts of the carpal bones.

    PubMed

    Van den Dungen, Sophie; Marchesi, Simona; Ezzedine, Rabih; Bindou, David; Lorea, Patrick

    2005-10-01

    Soft tissue ganglion cysts are the most common benign tumours of the wrist; their pathogenesis remains controversial. We prospectively screened the radiographic appearance of the wrists of 51 patients presenting to a single surgeon with dorsal wrist ganglions during a one-year period. Postero-anterior and lateral radiographs were systematically performed looking for possible associated intraosseous ganglion cysts. There were 51 dorsal soft tissue ganglion cysts in 51 patients. We detected 29 associated intraosseous ganglia in 24 patients (47%): 16 ganglia in the lunate bone (55%), 5 in the capitate bone, 7 in the scaphoid and 1 in the trapezoid. Mean size of the intraosseous ganglia was 3 mm (range, 2 to 5 mm). This high prevalence of intraosseous ganglia in association with soft tissue ganglia has to our knowledge never been reported previously. A common aetiology for these two types of ganglion cysts may explain this high association rate. PMID:16305077

  19. Evaluation of the percentage of ganglion cells in the ganglion cell layer of the rodent retina

    PubMed Central

    Schlamp, Cassandra L.; Montgomery, Angela D.; Mac Nair, Caitlin E.; Schuart, Claudia; Willmer, Daniel J.

    2013-01-01

    Purpose Retinal ganglion cells comprise a percentage of the neurons actually residing in the ganglion cell layer (GCL) of the rodent retina. This estimate is useful to extrapolate ganglion cell loss in models of optic nerve disease, but the values reported in the literature are highly variable depending on the methods used to obtain them. Methods We tested three retrograde labeling methods and two immunostaining methods to calculate ganglion cell number in the mouse retina (C57BL/6). Additionally, a double-stain retrograde staining method was used to label rats (Long-Evans). The number of total neurons was estimated using a nuclear stain and selecting for nuclei that met specific criteria. Cholinergic amacrine cells were identified using transgenic mice expressing Tomato fluorescent protein. Total neurons and total ganglion cell numbers were measured in microscopic fields of 104 µm2 to determine the percentage of neurons comprising ganglion cells in each field. Results Historical estimates of the percentage of ganglion cells in the mouse GCL range from 36.1% to 67.5% depending on the method used. Experimentally, retrograde labeling methods yielded a combined estimate of 50.3% in mice. A retrograde method also yielded a value of 50.21% for rat retinas. Immunolabeling estimates were higher at 64.8%. Immunolabeling may introduce overestimates, however, with non-specific labeling effects, or ectopic expression of antigens in neurons other than ganglion cells. Conclusions Since immunolabeling methods may overestimate ganglion cell numbers, we conclude that 50%, which is consistently derived from retrograde labeling methods, is a reliable estimate of the ganglion cells in the neuronal population of the GCL. PMID:23825918

  20. Degenerate astigmatic cavities

    NASA Astrophysics Data System (ADS)

    Courtois, Jérémie; Mohamed, Ajmal; Romanini, Daniele

    2013-10-01

    At the output of a high-finesse cavity a succession of Lissajous patterns may be observed as the cavity length is finely tuned inside a “degenerate region” around a reentrant spherical configuration. This behavior is ascribed to a small parasitic astigmatism of the cavity mirrors. Simple geometrical optics modeling confirms this hypothesis, and then a more realistic analysis using transverse Gaussian modes reveals that the Lissajous patterns correspond to an organization of the astigmatism-split modes into a finer substructure of degenerate modes relative to that of a reentrant spherical cavity. This provides a thorough understanding of the field patterns observed in the degenerate region, including an intriguing spatial symmetry of the patterns corresponding to opposite displacements with respect to a specific central cavity length. This investigation represents a generalization of the theory of reentrant spherical cavities to the astigmatic case.

  1. Ectopic ganglion in cauda equina: case report.

    PubMed

    Conner, Andrew K; Fung, Kar-Ming; Peterson, Jo Elle G; Glenn, Chad A; Martin, Michael D

    2016-06-01

    Macroscopic ectopic or heterotopic ganglionic tissue within the cauda equina is a very rare pathological finding and is usually associated with spinal dysraphism. However, it may mimic genuine neoplasms of the cauda equina. The authors describe a 29-year-old woman with a history of back pain, right leg pain, and urinary incontinence in whom imaging demonstrated an enhancing mass located in the cauda equina at the L1-2 interspace. The patient subsequently underwent biopsy and was found to have a focus of ectopic ganglionic tissue that was 1.3 cm in greatest dimension. To the authors' knowledge, ectopic or heterotopic ganglionic tissue within the cauda equina in a patient without evidence of spinal dysraphism has never been reported. This patient presented with imaging and clinical findings suggestive of a neoplasm, and an open biopsy proved the lesion to be ectopic ganglionic tissue. The authors suggest that ectopic ganglionic tissue be added to the list of differential diagnoses of a space-occupying lesion arising from the cauda equina. PMID:26871650

  2. Compression Neuropathy of the Radial Nerve Due to Ganglion Cysts

    PubMed Central

    Lifchez, Scott D.; Dzwierzynski, William W.

    2008-01-01

    Ganglions of the upper extremity are common. Radial nerve dysfunction, particularly radial sensory dysfunction, is a rare finding in association with a ganglion. We present our experience with two such ganglia and a review of the literature. PMID:18780092

  3. Expression of hermes gene is restricted to the ganglion cells in the retina.

    PubMed

    Piri, Natik; Kwong, Jacky M K; Song, Min; Caprioli, Joseph

    2006-09-11

    The RNA binding protein with multiple splicing 2, or hermes, is a member of the RRM (RNA recognition motif) family of RNA-binding proteins. In this study, we show that the hermes gene is expressed in the rat retina, and its expression is restricted to the ganglion cell layer. Double in situ hybridization with riboprobes corresponding to the hermes gene and Thy-1, the RGC marker in the retina, showed that the majority of the Thy-1 positive cells in the ganglion cell layer were also hermes positive. This was also shown by co-localization of the hermes in situ hybridization signals with the retrogradely labeled RGCs. Our observations suggest that hermes is expressed in the majority, if not all, of RGCs and is not restricted to only certain RGC types. Hermes in situ hybridization signals were not detected in the retinal sections of optic nerve transected animals, which are characterized by rapid and specific RGC degeneration. The dramatic reduction of the hermes mRNA level in axotomized retinas was also observed by semi-quantitative RT-PCR. The specific expression of hermes in retinal ganglion cells qualifies this gene as a potential RGC marker in the retina. Outside the retina, hermes is expressed in the heart, liver, and kidney, and to a lesser degree in the cerebellum, cortex, lung, and small intestine. PMID:16870336

  4. Intraneural ganglion cyst of the tibial nerve.

    PubMed

    Adn, M; Hamlat, A; Morandi, X; Guegan, Y

    2006-08-01

    Intraneural ganglion cyst of the tibial nerve is very rare. To date, only 5 cases of this entity in the popliteal fossa have been reported. We report a new case and review the previously reported cases. A 40-year-old man experienced a mild vague pain in the medial half of his right foot for 3 years. Magnetic resonance imaging scan demonstrated a soft-tissue mass along the right tibial nerve. At surgery, an intraneural ganglion cyst was evacuated. After 12 months, the patient was pain-free with no signs of recurrence. Trauma might be a contributing factor to the development of intraneural ganglion cysts. Application of microsurgical techniques is encouraged. PMID:16775659

  5. Frontotemporal Lobar Degeneration

    PubMed Central

    Josephs, Keith A.

    2009-01-01

    Synopsis Frontotemporal lobar degeneration (FTLD) is a syndromic diagnosis that encompasses at least three different variants. Imaging modalities are clinically useful in FTLD while pathology remains the gold standard for definitive diagnosis. To date three different genes have been identified that account for FTLD. PMID:17659185

  6. [Ganglion cysts of the hand and wrist].

    PubMed

    Sarig, Oren; Hass, Avraham; Oron, Amir

    2013-10-01

    Ganglion cysts are considered the most common tumor of the wrist and hand. They are most common between the second and fourth decades of life. The most common anatomical location is the dorsal wrist. This article includes a general review of these cysts including symptoms, pathology and methods of diagnosis, as well as a review of these cysts in specific anatomic locations. The article also includes an updated review of the literature comparing open surgery vs. arthroscopic treatment. The authors believe that arthroscopic surgery of ganglion cysts will gain an important role in the treatment of these cysts. PMID:24450035

  7. Current treatment of ganglion of the wrist.

    PubMed

    Ho, P C; Griffiths, J; Lo, W N; Yen, C H; Hung, L K

    2001-07-01

    Ganglion of the wrist is one of the the most common lesions of the hand. The cause of pain in an occult dorsal wrist ganglion has been linked to compression of the posterior interosseous nerve at the wrist. A case is presented in this paper and the pathoanatomy discussed. Ultrasound-guided aspiration after hyaluronidase instillation provided a useful alternative to surgery with a high success rate. Arthroscopic decompression for dorsal and palmar wrist ganglia offered the patient the benefit of smaller surgical scars and a high success rate. A description of the surgical techniques, pathoanatomy, and early results of the authors and a review of the literature is presented. PMID:11677666

  8. Age-Related Macular Degeneration

    MedlinePlus

    ... this page please turn Javascript on. Age-related Macular Degeneration What is AMD? Click for more information Age-related macular degeneration, ... the macula allows you to see fine detail. AMD Blurs Central Vision AMD blurs the sharp central ...

  9. X-82 to Treat Age-related Macular Degeneration

    ClinicalTrials.gov

    2016-08-16

    Age-Related Macular Degeneration (AMD); Macular Degeneration; Exudative Age-related Macular Degeneration; AMD; Macular Degeneration, Age-related, 10; Eye Diseases; Retinal Degeneration; Retinal Diseases

  10. Neurotrophic effects of taurine on spiral ganglion neurons in vitro.

    PubMed

    Rak, Kristen; Völker, Johannes; Jürgens, Lukas; Scherzad, Agmal; Schendzielorz, Philipp; Radeloff, Andreas; Jablonka, Sibylle; Mlynski, Robert; Hagen, Rudolf

    2014-11-12

    Taurine is an ubiquitary expressed aminosulfonic acid known to play an important role in the development and maintenance of the nervous system. It is distributed in the inner ear, contributing toward the protection of hair cells against aminoglycoside-induced or bilirubin-induced ototoxicity. Thus, the question arises whether taurine also has an influence on the cellular integrity of the auditory neurons. To test this hypothesis, isolated cells of the spiral ganglion were cocultured with taurine or the neurotrophic factors brain derived neurotrophic factor (BDNF) and neurotrophin-3 (NT-3) as controls. The analysis included cellular survival rate and neurite outgrowth. With application of taurine, the survival of glial cells and neurons was stimulated in a similar pattern, whereas BDNF and NT-3 only effected neuronal survival. Furthermore, administration of taurine resulted in enhanced neurite outgrowth comparable with the effect of the neurotrophic factors. These new insights on the neuromodulatory effects of taurine on auditory neurons suggest the use of this aminosulfonic acid to reduce the degeneration of auditory neurons in sensorineural hearing loss. Consecutively, a new therapeutical approach for the therapy of hearing impairment could be discussed. PMID:25202928

  11. Roles of NAD in Protection of Axon against Degeneration via SIRT1 Pathways.

    PubMed

    Zhang, Jing; Guo, Wei-Hua; Qi, Xiao-Xia; Li, Gui-Bao; Hu, Yan-Lai; Wu, Qi; Ding, Zhao-Xi; Li, Hong-Yu; Hao, Jing; Sun, Jin-Hao

    2016-04-30

    Axonal degeneration is a common pathological change of neurogenical disease which often arises before the neuron death. But it had not found any effective method to protect axon from degeneration. In this study we intended to confirm the protective effect of nicotinamide adenine dinucleotide (NAD), investigate the optimal administration dosage and time of NAD, and identify the relationship between silence signal regulating factor 1 (SIRT1) and axonal degeneration. An axonal degeneration model was established using dorsal root ganglion (DRG) neurons injured by vincristine to observe the protective effects of NAD to the injured axons. In addition, the potential contribution of the SIRT1 in axonal degeneration was also investigated. Through the 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, immunochemistry staining, axons counting and length measuring, transmission electron microscope (TEM) observation, we demonstrated that NAD played an important role in preventing axonal degeneration. Further study revealed that the expression of SIRT1 and phosphorylated Akt1 (p-Akt1) was up-regulated when NAD was added into the culturing medium. Taking together, our results demonstrated that NAD might delay the axonal degeneration through SIRT1/Akt1 pathways. PMID:27080463

  12. Ouabain-induced cochlear degeneration in rat

    PubMed Central

    Fu, Yong; Ding, Dalian; Jiang, Haiyan; Salvi, Richard

    2012-01-01

    Ouabain, an potent inhibitor of the Na+/K+-ATPase pump, selectively destroys spiral ganglion neurons (SGNs) in gerbils and mice whereas in guinea pigs it preferentially damages cochlear hair cells. To elucidate the effects of ouabain on the rat inner ear, a species widely used in research, 5 µl of 1 mM or 10 mM ouabain was applied to the round window membrane. Distortion product otoacoustic emissions (DPOAE) and auditory brainstem responses (ABR) were used identify functional deficits in hair cells and neurons respectively and histological techniques were used to characterize cochlear pathologies. High-frequency ABR thresholds were elevated after treatment with 1 mM ouabain whereas DPOAEs remained normal. In contrast, 10 mM ouabain increased ABR thresholds and reduced DPOAE amplitudes. Consistent with the physiological changes, 1 mM ouabain only damaged the SGNs and auditory nerve fibers in the basal turn of the cochlea whereas 10 mM ouabain destroyed both SGNs and cochlear hair cells; damage was greatest near the base and decreased toward the apex. The nuclei of degenerating SGNs and hair cells were condensed and fragmented and many cells were TUNEL-positive, morphological features of apoptotic cell death. Thus, ouabain-induced cochlear degeneration in rats is apoptotic and concentration dependent; low concentrations preferentially damage SGNs in the base of the cochlea, producing an animal model of partial auditory neuropathy, whereas high concentrations damage both hair cells and SGNs with damage decreasing from the base towards the apex. PMID:22476946

  13. Ouabain-induced cochlear degeneration in rat.

    PubMed

    Fu, Yong; Ding, Dalian; Jiang, Haiyan; Salvi, Richard

    2012-08-01

    Ouabain, a potent inhibitor of the Na+/K+-ATPase pump, selectively destroys spiral ganglion neurons (SGNs) in gerbils and mice, whereas in guinea pigs it preferentially damages cochlear hair cells. To elucidate the effects of ouabain on the rat inner ear, a species widely used in research, 5 μl of 1 or 10 mM ouabain was applied to the round window membrane. Distortion product otoacoustic emissions (DPOAE) and auditory brainstem responses (ABR) were used to identify functional deficits in hair cells and neurons, respectively, and histological techniques were used to characterize cochlear pathologies. High-frequency ABR thresholds were elevated after treatment with 1 mM ouabain, whereas DPOAEs remained normal. In contrast, 10 mM ouabain increased ABR thresholds and reduced DPOAE amplitudes. Consistent with the physiological changes, 1 mM ouabain only damaged the SGNs and auditory nerve fibers in the basal turn of the cochlea whereas 10 mM ouabain destroyed both SGNs and cochlear hair cells; damage was greatest near the base and decreased toward the apex. The nuclei of degenerating SGNs and hair cells were condensed and fragmented and many cells were TUNEL-positive, morphological features of apoptotic cell death. Thus, ouabain-induced cochlear degeneration in rats is apoptotic and concentration dependent; low concentrations preferentially damage SGNs in the base of the cochlea, producing an animal model of partial auditory neuropathy, whereas high concentrations damage both hair cells and SGNs with damage decreasing from the base toward the apex. PMID:22476946

  14. Ganglions of the hand and wrist.

    PubMed

    Thornburg, L E

    1999-01-01

    Ganglions of the hand and wrist are common benign lesions. They most frequently arise adjacent to joints and tendons, but may also be intratendinous or intraosseous. Treatment options include observation, aspiration, and surgical excision. Observation is acceptable in most instances. Indications for more aggressive treatment include pain, interference with activity, nerve compression, and imminent ulceration (in the case of some mucous cysts). The recurrence rate after puncture and aspiration is greater than 50% for cysts in most locations, but is less than 30% for cysts in the flexor tendon sheath. Surgical excision is effective, with a recurrence rate of only 5% if care is taken to completely excise the stalk of the cyst along with a small portion of joint capsule. Surgical treatment of occult ganglions is successful with accurate assessment of the source of the pain. Arthroscopic treatment of dorsal wrist ganglions is still experimental, but early results are encouraging. Ganglion surgery requires a formal operative environment and careful technique in order to minimize injury to adjacent structures and minimize the likelihood of recurrence. PMID:10434077

  15. Frontotemporal Lobar Degeneration

    PubMed Central

    Rabinovici, Gil D.; Miller, Bruce L.

    2010-01-01

    Frontotemporal lobar degeneration (FTLD) is a clinically and pathologically heterogeneous syndrome, characterized by progressive decline in behaviour or language associated with degeneration of the frontal and anterior temporal lobes. While the seminal cases were described at the turn of the 20th century, FTLD has only recently been appreciated as a leading cause of dementia, particularly in patients presenting before the age of 65 years. Three distinct clinical variants of FTLD have been described: (i) behavioural-variant frontotemporal dementia, characterized by changes in behaviour and personality in association with frontal-predominant cortical degeneration; (ii) semantic dementia, a syndrome of progressive loss of knowledge about words and objects associated with anterior temporal neuronal loss; and (iii) progressive nonfluent aphasia, characterized by effortful language output, loss of grammar and motor speech deficits in the setting of left perisylvian cortical atrophy. The majority of pathologies associated with FTLD clinical syndromes include either tau-positive (FTLD-TAU) or TAR DNA-binding protein 43 (TDP-43)-positive (FTLD-TDP) inclusion bodies. FTLD overlaps clinically and pathologically with the atypical parkinsonian disorders corticobasal degeneration and progressive supranuclear palsy, and with amyotrophic lateral sclerosis. The majority of familial FTLD cases are caused by mutations in the genes encoding microtubule-associated protein tau (leading to FTLD-TAU) or progranulin (leading to FTLD-TDP). The clinical and pathologic heterogeneity of FTLD poses a significant diagnostic challenge, and in vivo prediction of underlying histopathology can be significantly improved by supplementing the clinical evaluation with genetic tests and emerging biological markers. Current pharmacotherapy for FTLD focuses on manipulating serotonergic or dopaminergic neurotransmitter systems to ameliorate behavioural or motor symptoms. However, recent advances in FTLD

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

    PubMed Central

    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

  17. From connected pathway flow to ganglion dynamics

    NASA Astrophysics Data System (ADS)

    Rücker, M.; Berg, S.; Armstrong, R. T.; Georgiadis, A.; Ott, H.; Schwing, A.; Neiteler, R.; Brussee, N.; Makurat, A.; Leu, L.; Wolf, M.; Khan, F.; Enzmann, F.; Kersten, M.

    2015-05-01

    During imbibition, initially connected oil is displaced until it is trapped as immobile clusters. While initial and final states have been well described before, here we image the dynamic transient process in a sandstone rock using fast synchrotron-based X-ray computed microtomography. Wetting film swelling and subsequent snap off, at unusually high saturation, decreases nonwetting phase connectivity, which leads to nonwetting phase fragmentation into mobile ganglia, i.e., ganglion dynamics regime. We find that in addition to pressure-driven connected pathway flow, mass transfer in the oil phase also occurs by a sequence of correlated breakup and coalescence processes. For example, meniscus oscillations caused by snap-off events trigger coalescence of adjacent clusters. The ganglion dynamics occurs at the length scale of oil clusters and thus represents an intermediate flow regime between pore and Darcy scale that is so far dismissed in most upscaling attempts.

  18. Telocytes of the human adult trigeminal ganglion.

    PubMed

    Rusu, Mugurel Constantin; Cretoiu, Dragos; Vrapciu, Alexandra Diana; Hostiuc, Sorin; Dermengiu, Dan; Manoiu, Vasile Sorin; Cretoiu, Sanda Maria; Mirancea, Nicolae

    2016-06-01

    Telocytes (TCs) are typically defined as cells with telopodes by their ultrastructural features. Their presence was reported in various organs, however little is known about their presence in human trigeminal ganglion. To address this issue, samples of trigeminal ganglia were tested by immunocytochemistry for CD34 and examined by transmission electron microscopy (TEM). We found that TCs are CD34 positive and form networks within the ganglion in close vicinity to microvessels and nerve fibers around the neuronal-glial units (NGUs). TEM examination confirmed the existence of spindle-shaped and bipolar TCs with one or two telopodes measuring between 15 to 53 μm. We propose that TCs are cells with stemness capacity which might contribute in regeneration and repair processes by: modulation of the stem cell activity or by acting as progenitors of other cells present in the normal tissue. In addition, further studies are needed to establish if they might influence the neuronal circuits. PMID:27147447

  19. Ganglion cysts in a juvenile dog.

    PubMed

    Cho, K O; Park, N Y; Kang, M I; Umemura, K; Itakura, C

    2000-07-01

    Ganglion cysts were diagnosed in a 4-month-old male Afghan Hound. Grossly, the subcutaneous ovoid cysts around the caudal right elbow joint and left ischiatic tuberosity had abundant mucinous fluid and internal folding. The lesions recurred twice around the elbow joint after surgical removal. Neither cyst communicated with the joint cavity. Histologically, the cyst wall consisted of inner myxomatous and outer immature connective tissue. Some parts of the cyst wall had various stages of myxoid metaplasia of collagen tissue leading to new cyst formation. Ultrastructural study revealed that cells in the myxoid metaplastic lesion had well-developed cytoplasmic secretory elements, including abundant rough endoplasmic reticulum, Golgi apparatus, and many smooth-walled vesicles. These ganglion cysts apparently resulted from the metaplasia of fibroblasts to secreting cells. PMID:10896396

  20. Ganglion cysts and carpal tunnel syndrome.

    PubMed

    Kerrigan, J J; Bertoni, J M; Jaeger, S H

    1988-09-01

    We review 12 cases of ganglion cyst with carpal tunnel syndrome in 11 patients seen at the Hand Rehabilitation Center. Mean age was 42 years (range, 28 to 60 years). One half of the cysts were associated with direct trauma, usually with wrist hyperextension. Symptoms usually developed after the appearance or sudden growth of the cyst. Motor conduction or distal sensory latency was abnormal in seven of eight studied cases. Tinel's sign on tapping the cyst may be pathognomonic for this syndrome. Cyst removal and incision of the flexor retinaculum relieved the symptoms in 11 cases. The other case had total resolution after spontaneous cyst rupture. This syndrome is successfully treated with cyst decompression with release of the carpal canal and has an excellent prognosis. To our knowledge this represents the largest operative series of carpal tunnel syndrome and ganglion cyst. PMID:3241055

  1. Learning LM Specificity for Ganglion Cells

    NASA Technical Reports Server (NTRS)

    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.

  2. Simultaneous bilateral ganglion cysts of the anterior cruciate ligaments

    PubMed Central

    Demircay, Emre; Ofluoglu, Demet; Ozel, Omer; Oztop, Pinar

    2015-01-01

    Intra-articular ganglion cysts of the anterior cruciate ligament (ACL) are rare, and bilateral ganglion cysts are even rarer. These cysts may cause intermittent or chronic nonspecific knee discomfort. Although three cases of bilateral ganglion cysts have been reported in the literature, the knees were not simultaneously affected in those cases. Herein, we report the case of a 56-year-old woman who presented with simultaneous bilateral ganglion cysts of the ACL that were symptomatic. She was successfully treated with arthroscopic resection and debridement. We also present a brief review of the literature, highlighting the aetiology, diagnosis and management of ganglion cysts of the ACL. To the best of our knowledge, this is the first report of simultaneous bilateral intra-articular ganglion cysts of the ACL. PMID:25917477

  3. Simultaneous bilateral ganglion cysts of the anterior cruciate ligaments.

    PubMed

    Demircay, Emre; Ofluoglu, Demet; Ozel, Omer; Oztop, Pinar

    2015-04-01

    Intra-articular ganglion cysts of the anterior cruciate ligament (ACL) are rare, and bilateral ganglion cysts are even rarer. These cysts may cause intermittent or chronic nonspecific knee discomfort. Although three cases of bilateral ganglion cysts have been reported in the literature, the knees were not simultaneously affected in those cases. Herein, we report the case of a 56-year-old woman who presented with simultaneous bilateral ganglion cysts of the ACL that were symptomatic. She was successfully treated with arthroscopic resection and debridement. We also present a brief review of the literature, highlighting the aetiology, diagnosis and management of ganglion cysts of the ACL. To the best of our knowledge, this is the first report of simultaneous bilateral intra-articular ganglion cysts of the ACL. PMID:25917477

  4. Aberrant Activity in Degenerated Retinas Revealed by Electrical Imaging

    PubMed Central

    Zeck, Günther

    2016-01-01

    In this review, I present and discuss the current understanding of aberrant electrical activity found in the ganglion cell layer (GCL) of rod-degenerated (rd) mouse retinas. The reported electrophysiological properties revealed by electrical imaging using high-density microelectrode arrays can be subdivided between spiking activity originating from retinal ganglion cells (RGCs) and local field potentials (LFPs) reflecting strong trans-membrane currents within the GCL. RGCs in rd retinas show increased and rhythmic spiking compared to age-matched wild-type retinas. Fundamental spiking frequencies range from 5 to 15 Hz in various mouse models. The rhythmic RGC spiking is driven by a presynaptic network comprising AII amacrine and bipolar cells. In the healthy retina this rhythm-generating circuit is inhibited by photoreceptor input. A unique physiological feature of rd retinas is rhythmic LFP manifested as spatially-restricted low-frequency (5–15 Hz) voltage changes. Their spatiotemporal characterization revealed propagation and correlation with RGC spiking. LFPs rely on gap-junctional coupling and are shaped by glycinergic and by GABAergic transmission. The aberrant RGC spiking and LFPs provide a simple readout of the functionality of the remaining retinal circuitry which can be used in the development of improved vision restoration strategies. PMID:26903810

  5. Melanopsin retinal ganglion cell loss in Alzheimer disease

    PubMed Central

    Ross‐Cisneros, Fred N.; Koronyo, Yosef; Hannibal, Jens; Gallassi, Roberto; Cantalupo, Gaetano; Sambati, Luisa; Pan, Billy X.; Tozer, Kevin R.; Barboni, Piero; Provini, Federica; Avanzini, Pietro; Carbonelli, Michele; Pelosi, Annalisa; Chui, Helena; Liguori, Rocco; Baruzzi, Agostino; Koronyo‐Hamaoui, Maya; Sadun, Alfredo A.; Carelli, Valerio

    2015-01-01

    Objective Melanopsin retinal ganglion cells (mRGCs) are photoreceptors driving circadian photoentrainment, and circadian dysfunction characterizes Alzheimer disease (AD). We investigated mRGCs in AD, hypothesizing that they contribute to circadian dysfunction. Methods We assessed retinal nerve fiber layer (RNFL) thickness by optical coherence tomography (OCT) in 21 mild‐moderate AD patients, and in a subgroup of 16 we evaluated rest–activity circadian rhythm by actigraphy. We studied postmortem mRGCs by immunohistochemistry in retinas, and axons in optic nerve cross‐sections of 14 neuropathologically confirmed AD patients. We coimmunostained for retinal amyloid β (Aβ) deposition and melanopsin to locate mRGCs. All AD cohorts were compared with age‐matched controls. Results We demonstrated an age‐related optic neuropathy in AD by OCT, with a significant reduction of RNFL thickness (p = 0.038), more evident in the superior quadrant (p = 0.006). Axonal loss was confirmed in postmortem AD optic nerves. Abnormal circadian function characterized only a subgroup of AD patients. Sleep efficiency was significantly reduced in AD patients (p = 0.001). We also found a significant loss of mRGCs in postmortem AD retinal specimens (p = 0.003) across all ages and abnormal mRGC dendritic morphology and size (p = 0.003). In flat‐mounted AD retinas, Aβ accumulation was remarkably evident inside and around mRGCs. Interpretation We show variable degrees of rest–activity circadian dysfunction in AD patients. We also demonstrate age‐related loss of optic nerve axons and specifically mRGC loss and pathology in postmortem AD retinal specimens, associated with Aβ deposition. These results all support the concept that mRGC degeneration is a contributor to circadian rhythm dysfunction in AD. ANN NEUROL 2016;79:90–109 PMID:26505992

  6. Macular degeneration - age-related

    MedlinePlus

    Age-related macular degeneration (ARMD); AMD ... distorted and wavy. There may be a small dark spot in the center of your vision that ... leafy vegetables, may also decrease your risk of age-related macular degeneration. If you have wet AMD, ...

  7. Melanopsin-expressing intrinsically photosensitive retinal ganglion cells in retinal disease.

    PubMed

    Feigl, Beatrix; Zele, Andrew J

    2014-08-01

    Melanopsin-containing intrinsically photosensitive retinal ganglion cells (ipRGCs) are a class of photoreceptors with established roles in non-image-forming processes. Their contributions to image-forming vision may include the estimation of brightness. Animal models have been central for understanding the physiological mechanisms of ipRGC function and there is evidence of conservation of function across species. Intrinsically photosensitive retinal ganglion cells can be divided into five ganglion cell subtypes that show morphological and functional diversity. Research in humans has established that ipRGCs signal environmental irradiance to entrain the central body clock to the solar day for regulating circadian processes and sleep. In addition, ipRGCs mediate the pupil light reflex (PLR), making the PLR a readily accessible behavioral marker of ipRGC activity. Less is known about ipRGC function in retinal and optic nerve disease, with emerging research providing insight into their function in diabetes, retinitis pigmentosa, glaucoma, and hereditary optic neuropathy. We briefly review the anatomical distributions, projections, and basic physiological mechanisms of ipRGCs and their proposed and known functions in animals and humans with and without eye disease. We introduce a paradigm for differentiating inner and outer retinal inputs to the pupillary control pathway in retinal disease and apply this paradigm to patients with age-related macular degeneration (AMD). In these cases of patients with AMD, we provide the initial evidence that ipRGC function is altered and that the dysfunction is more pronounced in advanced disease. Our perspective is that with refined pupillometry paradigms, the PLR can be extended to AMD assessment as a tool for the measurement of inner and outer retinal dysfunction. PMID:24879087

  8. Brain-derived neurotrophic factor prevents dendritic retraction of adult mouse retinal ganglion cells.

    PubMed

    Binley, Kate E; Ng, Wai S; Barde, Yves-Alain; Song, Bing; Morgan, James E

    2016-08-01

    We used cultured adult mouse retinae as a model system to follow and quantify the retraction of dendrites using diolistic labelling of retinal ganglion cells (RGCs) following explantation. Cell death was monitored in parallel by nuclear staining as 'labelling' with RGC and apoptotic markers was inconsistent and exceedingly difficult to quantify reliably. Nuclear staining allowed us to delineate a lengthy time window during which dendrite retraction can be monitored in the absence of RGC death. The addition of brain-derived neurotrophic factor (BDNF) produced a marked reduction in dendritic degeneration, even when application was delayed for 3 days after retinal explantation. These results suggest that the delayed addition of trophic factors may be functionally beneficial before the loss of cell bodies in the course of conditions such as glaucoma. PMID:27285957

  9. What Is Age-Related Macular Degeneration?

    MedlinePlus

    ... Degeneration Diagnosis: How is AMD diagnosed? Macular Degeneration Treatment: How is AMD Treated? Macular ... macular degeneration (AMD) is a deterioration or breakdown of the eye's macula. The macula is a small area in the ...

  10. Rhythmic Ganglion Cell Activity in Bleached and Blind Adult Mouse Retinas

    PubMed Central

    Menzler, Jacob; Channappa, Lakshmi; Zeck, Guenther

    2014-01-01

    In retinitis pigmentosa – a degenerative disease which often leads to incurable blindness- the loss of photoreceptors deprives the retina from a continuous excitatory input, the so-called dark current. In rodent models of this disease this deprivation leads to oscillatory electrical activity in the remaining circuitry, which is reflected in the rhythmic spiking of retinal ganglion cells (RGCs). It remained unclear, however, if the rhythmic RGC activity is attributed to circuit alterations occurring during photoreceptor degeneration or if rhythmic activity is an intrinsic property of healthy retinal circuitry which is masked by the photoreceptor’s dark current. Here we tested these hypotheses by inducing and analysing oscillatory activity in adult healthy (C57/Bl6) and blind mouse retinas (rd10 and rd1). Rhythmic RGC activity in healthy retinas was detected upon partial photoreceptor bleaching using an extracellular high-density multi-transistor-array. The mean fundamental spiking frequency in bleached retinas was 4.3 Hz; close to the RGC rhythm detected in blind rd10 mouse retinas (6.5 Hz). Crosscorrelation analysis of neighbouring wild-type and rd10 RGCs (separation distance <200 µm) reveals synchrony among homologous RGC types and a constant phase shift (∼70 msec) among heterologous cell types (ON versus OFF). The rhythmic RGC spiking in these retinas is driven by a network of presynaptic neurons. The inhibition of glutamatergic ganglion cell input or the inhibition of gap junctional coupling abolished the rhythmic pattern. In rd10 and rd1 retinas the presynaptic network leads to local field potentials, whereas in bleached retinas additional pharmacological disinhibition is required to achieve detectable field potentials. Our results demonstrate that photoreceptor bleaching unmasks oscillatory activity in healthy retinas which shares many features with the functional phenotype detected in rd10 retinas. The quantitative physiological differences advance the

  11. Cobalamin C Deficiency Shows a Rapidly Progressing Maculopathy With Severe Photoreceptor and Ganglion Cell Loss

    PubMed Central

    Bonafede, Lucas; Ficicioglu, Can H.; Serrano, Leona; Han, Grace; Morgan, Jessica I. W.; Mills, Monte D.; Forbes, Brian J.; Davidson, Stefanie L.; Binenbaum, Gil; Kaplan, Paige B.; Nichols, Charles W.; Verloo, Patrick; Leroy, Bart P.; Maguire, Albert M.; Aleman, Tomas S.

    2015-01-01

    Purpose To describe in detail the retinal structure and function of a group of patients with cobalamin C (cblC) disease. Methods Patients (n = 11, age 4 months to 15 years) with cblC disease (9/11, early onset) diagnosed by newborn screening underwent complete ophthalmic examinations, fundus photography, near-infrared reflectance imaging, and spectral-domain optical coherence tomography (SD-OCT). Electroretinograms (ERGs) were performed in a subset of patients. Results Patients carried homozygous or compound heterozygote mutations in the methylmalonic aciduria and homocystinuria type C (MMACHC) gene. Late-onset patients had a normal exam. All early-onset patients showed a maculopathy; older subjects had a retina-wide degeneration (n = 4; >7 years of age). In general, retinal changes were first observed before 1 year of age and progressed within months to a well-established maculopathy. Pseudocolobomas were documented in three patients. Measurable visual acuities ranged from 20/200 to 20/540. Nystagmus was present in 8/11 patients; 5/6 patients had normal ERGs; 1/6 had reduced rod-mediated responses. Spectral-domain OCT showed macular thinning, with severe ganglion cell layer (GCL) and outer nuclear layer (ONL) loss. Inner retinal thickening was observed in areas of total GCL/ONL loss. A normal lamination pattern in the peripapillary nasal retina was often seen despite severe central and/or retina-wide disease. Conclusions Patients with early-onset cblC and MMACHC mutations showed an early-onset, unusually fast-progressing maculopathy with severe central ONL and GCL loss. An abnormally thickened inner retina supports a remodeling response to both photoreceptor and ganglion cell degeneration and/or an interference with normal development in early-onset cblC. PMID:26658511

  12. Concerted Signaling by Retinal Ganglion Cells

    NASA Astrophysics Data System (ADS)

    Meister, Markus; Lagnado, Leon; Baylor, Denis A.

    1995-11-01

    To analyze the rules that govern communication between eye and brain, visual responses were recorded from an intact salamander retina. Parallel observation of many retinal ganglion cells with a microelectrode array showed that nearby neurons often fired synchronously, with spike delays of less than 10 milliseconds. The frequency of such synchronous spikes exceeded the correlation expected from a shared visual stimulus up to 20-fold. Synchronous firing persisted under a variety of visual stimuli and accounted for the majority of action potentials recorded. Analysis of receptive fields showed that concerted spikes encoded information not carried by individual cells; they may represent symbols in a multineuronal code for vision.

  13. The successful arthroscopic treatment of suprascapular intraneural ganglion cysts.

    PubMed

    Prasad, Nikhil K; Spinner, Robert J; Smith, Jay; Howe, Benjamin M; Amrami, Kimberly K; Iannotti, Joseph P; Dahm, Diane L

    2015-09-01

    OBJECT High-resolution magnetic resonance imaging (MRI) can distinguish between intraneural ganglion cysts and paralabral (extraneural) cysts at the glenohumeral joint. Suprascapular intraneural ganglion cysts share the same pathomechanism as their paralabral counterparts, emanating from a tear in the glenoid labrum. The authors present 2 cases to demonstrate that the identification and arthroscopic repair of labral tears form the cornerstone of treatment for intraneural ganglion cysts of the suprascapular nerve. METHODS Two patients with suprascapular intraneural ganglion cysts were identified: 1 was recognized and treated prospectively, and the other, previously reported as a paralabral cyst, was identified retrospectively through the reinter-pretation of high-resolution MR images. RESULTS Both patients achieved full functional recovery and had complete radiological involution of the intraneural ganglion cysts at the 3-month and 12-month follow-ups, respectively. CONCLUSIONS Previous reports of suprascapular intraneural ganglion cysts described treatment by an open approach to decompress the cysts and resect the articular nerve branch to the glenohumeral joint. The 2 cases in this report demonstrate that intraneural ganglion cysts, similar to paralabral cysts, can be treated with arthroscopic repair of the glenoid labrum without resection of the articular branch. This approach minimizes surgical morbidity and directly addresses the primary etiology of intraneural and extraneural ganglion cysts. PMID:26323813

  14. Bilateral Thoracic Ganglion Cyst : A Rare Case Report

    PubMed Central

    Kazanci, Burak; Tehli, Ozkan; Guclu, Bulent

    2013-01-01

    Ganglion cysts usually arise from the tissues around the facet joints. It is usually associated with degenerative cahanges in facet joints. Bilateral thoracic ganglion cysts are very rare and there is no previous case that located in bilateral intervertebral foramen compressing the L1 nerve root associated with severe radiculopathy. We report a 53 years old woman who presented with bilateral groin pain and severe numbness. Magnetic resonance imaging revealed bilateral cystic mass in the intervertebral foramen between 12th thoracal and 1st lumbar vertebrae. The cystic lesions were removed after bilateral exposure of Th12-L1 foramens. The result of hystopathology confirmed the diagnosis as ganglion cyst. The ganglion cyst may compromise lumbar dorsal ganglion when it located in the intervertebral foramen. The surgeon should keep this rare entity in their mind for differential diagnosis. PMID:23908708

  15. Therapeutic Approach of Wrist Ganglion Using Electroacupuncture: Two Case Reports

    PubMed Central

    Kim, Kyoung Min; Lee, Sung Hoon; Jung, A Young; Nam, Doo Hyoun; Cheon, Ji Hwan

    2014-01-01

    A ganglion cyst is a relatively common benign tumor on the wrist. Conservative and surgical approaches have been used for its treatment. Various conservative treatment methods have been suggested such as reassurance, aspiration, sclerosant injection, and direct compression. But, there is no acceptable treatment of choice yet because each suggested method has a relatively high recurrence rate. We want to report two cases in which the size of the wrist ganglion was decreased by using electroacupuncture. One patient presented with a chronic ganglion for six years and the other patient presented with a recently occurred acute ganglion. We applied electroacupuncture for 20 minutes once a week for eight weeks to both of them. Afterwards, the size of the wrist ganglion diminished in the follow-up sonography and the accompanying pain was also relieved. Herein we report both cases along with a review of the relevant literature. PMID:25024969

  16. Salzmann's Nodular Degeneration.

    PubMed

    Maharana, Prafulla K; Sharma, Namrata; Das, Sujata; Agarwal, Tushar; Sen, Seema; Prakash, Gaurav; Vajpayee, Rasik B

    2016-01-01

    Salzmann's nodular degeneration (SND) is a rare, noninflammatory, slowly progressive degenerative disease of the cornea that is characterized by the appearance of nodular bluish gray opacities that vary in number and size. It is usually bilateral; most commonly occurring in people aged 50-60 years old, with a female preponderance; and often associated with a history of prior corneal inflammation. The clinical features usually depend on the location of the nodules. Generally, the nodules of SND are bluish white to gray in color, 1-2 mm in size, and round, conical or prismatic in shape. The overlying Bowman's layer is usually absent from the nodular areas and is partially replaced by granular Periodic Acid Schiff-positive eosinophilic material resembling the basement membrane. Diagnostic investigations include ultrasonic pachymetry, anterior segment optical coherence tomography, ultrasound biomicroscopy, and confocal microscopy. The majority of patients respond well to conservative management with topical lubricants; severe cases may require surgical intervention. The various surgical modalities described include superficial keratectomy, which may be combined with phototherapeutic keratectomy and keratoplasty. Various modifications of these procedures include the use of alcohol-assisted epithelial delamination, intraoperative mitomycin-C or amniotic membrane transplantation to make the procedure easy, reduce the risk of recurrence and improve postoperative comfort. Recurrences are rarely reported; overall, the visual prognosis following treatment is optimal. PMID:26462409

  17. Spectral-Domain Optical Coherence Tomography Documentation of Transsynaptic Retinal Degeneration.

    PubMed

    Schwartz, Stephen G; Pasol, Joshua; Lam, Byron L; Flynn, Harry W

    2016-08-01

    Patients with post-geniculate neurologic disease and corresponding visual field loss may have ophthalmologic abnormalities detectable by spectral-domain optical coherence tomography (SD-OCT), presumably by transsynaptic retrograde retinal degeneration. Here, three such patients (ages 13 years through 75 years) illustrate thinning of the macula and ganglion cell complex corresponding to zones of visual field loss. Thinning of the retinal nerve fiber layer is not notable in these patients. SD-OCT may be a useful technique in diagnosing and following patients with post-geniculate neurologic disease. [Ophthalmic Surg Lasers Imaging Retina. 2016;47:768-772.]. PMID:27548455

  18. The retinal ganglion cell classes of New World primates.

    PubMed

    Yamada, E S; Silveira, L C; Gomes, F L; Lee, B B

    1996-12-01

    In the primate retina there are distinct ganglion cell classes, exhibiting particular morphologies and central projections, each responsible for conveying particular types of visual information to the brain. The chief retinal inputs to the cortex arise from specific ganglion cell classes, M-ganglion cells, responsible for carrying the luminance signal, and P-ganglion cells, that convey the red-green color opponent signal, as well as high contrast luminance signal. There are other ganglion cell classes, such as small-field bistratified cells, exhibiting dendrites that stratify at two different levels in the inner plexiform layer, which convey the blue-yellow color opponent signal. Most published data concerning primate retinal ganglion cell anatomy and physiology have been obtained from Old World species. Studies on New World monkeys have recently become of interest since they differ from the Old World monkeys with respect to the color vision inheritance pattern. On reviewing retinal ganglion cell layer organization in New World monkeys, it seems that there are more similarities than differences in relation to the Old World monkeys. Diurnal genera of New World monkeys exhibit a well-developed fovea centralis and ganglion cell density peak, as well as peripheral density values which are in the range reported for Old World monkeys and human. Moreover, all the major ganglion cell classes identified in Old World monkeys are also present in New World primates. Up to now, no obvious anatomical differences between dichromats and trichromats have been reported. The only genus that is significantly different from the others is the Aotus. It exhibits lower ganglion cell density in the central retina, and apparently lacks the small-field bistratified cells. PMID:9394516

  19. Differential Calcium Signaling Mediated by Voltage-Gated Calcium Channels in Rat Retinal Ganglion Cells and Their Unmyelinated Axons

    PubMed Central

    Sargoy, Allison; Sun, Xiaoping

    2014-01-01

    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. PMID:24416240

  20. Disentangling the Role of Cortico-Basal Ganglia Loops in Top-Down and Bottom-Up Visual Attention: An Investigation of Attention Deficits in Parkinson Disease.

    PubMed

    Tommasi, Giorgio; Fiorio, Mirta; Yelnik, Jérôme; Krack, Paul; Sala, Francesca; Schmitt, Emmanuelle; Fraix, Valérie; Bertolasi, Laura; Le Bas, Jean-François; Ricciardi, Giuseppe Kenneth; Fiaschi, Antonio; Theeuwes, Jan; Pollak, Pierre; Chelazzi, Leonardo

    2015-06-01

    It is solidly established that top-down (goal-driven) and bottom-up (stimulus-driven) attention mechanisms depend on distributed cortical networks, including prefrontal and frontoparietal regions. On the other hand, it is less clear whether the BG also contribute to one or the other of these mechanisms, or to both. The current study was principally undertaken to clarify this issue. Parkinson disease (PD), a neurodegenerative disorder primarily affecting the BG, has proven to be an effective model for investigating the contribution of the BG to different brain functions; therefore, we set out to investigate deficits of top-down and bottom-up attention in a selected cohort of PD patients. With this objective in mind, we compared the performance on three computerized tasks of two groups of 12 parkinsonian patients (assessed without any treatment), one otherwise pharmacologically treated and the other also surgically treated, with that of a group of controls. The main behavioral tool for our study was an attentional capture task, which enabled us to tap the competition between top-down and bottom-up mechanisms of visual attention. This task was suitably combined with a choice RT and a simple RT task to isolate any specific deficit of attention from deficits in motor response selection and initiation. In the two groups of patients, we found an equivalent increase of attentional capture but also comparable delays in target selection in the absence of any salient distractor (reflecting impaired top-down mechanisms) and movement initiation compared with controls. In contrast, motor response selection processes appeared to be prolonged only in the operated patients. Our results confirm that the BG are involved in both motor and cognitive domains. Specifically, damage to the BG, as it occurs in PD, leads to a distinct deficit of top-down control of visual attention, and this can account, albeit indirectly, for the enhancement of attentional capture, reflecting weakened ability of top-down mechanisms to antagonize bottom-up control. PMID:25514652

  1. Nutrition and retinal degenerations.

    PubMed

    Berson, E L

    2000-01-01

    Considerable progress has been made in the understanding and management of degenerative diseases of the retina involving photoreceptors. Nutritional approaches to treatment have proved successful in the case of the common forms of retinitis pigmentosa (supplementation with vitamin A), Bassen-Kornzweig disease (supplementation with vitamins A, E, and K), gyrate atrophy (low-protein, low-arginine diet and/or supplementation with vitamin B6), and Refsum disease (low-phytol, low-phytanic acid diet). The night blindness associated with Sorsby fundus dystrophy can be reversed over the short term with vitamin A. A significant trend for decreased risk for advanced or exudative ARMD has been reported among those whose diets contain a higher content of carotenoids, such as spinach and collard greens. A randomized trial is in progress to determine whether beta-carotene, vitamin C, and vitamin E as well as trace minerals, particularly zinc, will modify the course of ARMD. The difficulties that patients with retinal degenerations face as a result of their diminishing vision, sometimes over decades, cannot be underestimated. Nutritional therapy has proved effective in modifying the course of a number of these conditions; the therapeutic benefit of nutritional modification in diseases that have a genetic basis is of particular interest. Further research is warranted to determine the mechanisms by which these treatments provide their benefit as well as to identify other conditions that may yield to nutritional intervention. Risk-factor analyses of well-defined populations followed over time with food-frequency questionnaires in conjunction with careful assessments of visual function may reveal other dietary constituents that can modify the course of degenerative diseases of the retina. PMID:11064860

  2. Tendoscopic Excision of an Intratendinous Ganglion in the Flexor Hallucis Longus Tendon: A Case Report.

    PubMed

    Endo, Jun; Yamaguchi, Satoshi; Sasho, Takahisa

    2016-01-01

    Intratendinous ganglion cysts are rare lesions of unknown etiology that originate within a tendon. We report the case of a 34-year-old female with an intratendinous ganglion in the plantar portion of the flexor hallucis longus tendon. The intratendinous ganglion recurred after ultrasound-guided needle aspiration. Tendoscopic excision of the intratendinous ganglion cyst achieved a satisfactorily result without recurrence. PMID:25456345

  3. Retinal Changes in an ATP-Induced Model of Retinal Degeneration

    PubMed Central

    Aplin, Felix P.; Vessey, Kirstan A.; Luu, Chi D.; Guymer, Robyn H.; Shepherd, Robert K.; Fletcher, Erica L.

    2016-01-01

    In rodents and felines, intravitreal administration of adenosine triphosphate (ATP) has been shown to induce photoreceptor death providing a tractable model of retinal degeneration in these species. This study investigated the long term effects of photoreceptor loss in an ATP induced feline model of retinal degeneration. Six normal sighted felines were unilaterally blinded using intravitreal ATP injections and assessed using electroretinography (ERG) and optical coherence tomography (OCT). At 30 h (n = 3) or 12 weeks (n = 3) post-injection, the animals were euthanized and the eyes enucleated. Retinae were sectioned and labeled using immunohistochemistry for markers of cell death, neural remodeling and gliosis. Ongoing cell death and retinal degeneration was observed in the outer retina at both 30 h and 12 weeks following unilateral ATP injection. Markers of mid to late-stage retinal remodeling such as cell displacement and aberrant neurite growth were observed in the inner retina at 12 weeks post-injection. Ganglion cells appeared to remain intact in ATP injected eyes. Müller cell gliosis was observed throughout the inner and outer retina, in some parts completely enveloping and/or displacing the surviving neural tissue. Our data suggests that the ATP injected feline retina continues to undergo progressive retinal degeneration and exhibits abnormalities consistent with a description of retinal remodeling commonly seen in other models of retinal degeneration. These findings validate the use of intravitreal ATP injection in feline as a large animal model of retinal degeneration which may aid in development of therapies aiming to restore visual function after photoreceptor degeneration. PMID:27199678

  4. Selectivity for multiple stimulus features in retinal ganglion cells.

    PubMed

    Fairhall, Adrienne L; Burlingame, C Andrew; Narasimhan, Ramesh; Harris, Robert A; Puchalla, Jason L; Berry, Michael J

    2006-11-01

    Under normal viewing conditions, retinal ganglion cells transmit to the brain an encoded version of the visual world. The retina parcels the visual scene into an array of spatiotemporal features, and each ganglion cell conveys information about a small set of these features. We study the temporal features represented by salamander retinal ganglion cells by stimulating with dynamic spatially uniform flicker and recording responses using a multi-electrode array. While standard reverse correlation methods determine a single stimulus feature--the spike-triggered average--multiple features can be relevant to spike generation. We apply covariance analysis to determine the set of features to which each ganglion cell is sensitive. Using this approach, we found that salamander ganglion cells represent a rich vocabulary of different features of a temporally modulated visual stimulus. Individual ganglion cells were sensitive to at least two and sometimes as many as six features in the stimulus. While a fraction of the cells can be described by a filter-and-fire cascade model, many cells have feature selectivity that has not previously been reported. These reverse models were able to account for 80-100% of the information encoded by ganglion cells. PMID:16914609

  5. Methylene blue-enhanced arthroscopic resection of dorsal wrist ganglions.

    PubMed

    Lee, Byung Joo; Sawyer, Gregory A; Dasilva, Manuel F

    2011-12-01

    The ganglion is the most common soft tissue mass of the hand and wrist. Over the past 10 to 15 years, there has been a growing interest in arthroscopic treatment of dorsal wrist ganglions. Proposed advantages of arthroscopy include greater motion (particularly wrist flexion), improved cosmesis, and potential to identify/treat other intra-articular pathology. Despite the documented clinical success of arthroscopic ganglion excision, limitations include inconsistent identification of the ganglion stalk. Our described technique offers a means by which to improve visualization of the ganglion stalk intra-articularly to produce a more effective and efficient arthroscopic ganglion excision. During the procedure, a small volume of methylene blue solution is injected into the cyst. Its communication with the joint is apparent arthroscopically, thus identifying the location of the stalk. With the ability to precisely identify the ganglion stalk using an injection of methylene blue, the surgeon can direct the arthroscopic debridement toward the appropriate pathologic tissue. Unnecessary debridement of uninvolved tissue can be avoided with the technique. This also allows for optimal portal placement and, in particular, indicates whether a midcarpal portal should be employed. This should result in fewer recurrences, decreased operative time, and less iatrogenic injury. PMID:22105637

  6. Neuronal cell lines as model dorsal root ganglion neurons

    PubMed Central

    Yin, Kathleen; Baillie, Gregory J

    2016-01-01

    Background Dorsal root ganglion neuron-derived immortal cell lines including ND7/23 and F-11 cells have been used extensively as in vitro model systems of native peripheral sensory neurons. However, while it is clear that some sensory neuron-specific receptors and ion channels are present in these cell lines, a systematic comparison of the molecular targets expressed by these cell lines with those expressed in intact peripheral neurons is lacking. Results In this study, we examined the expression of RNA transcripts in the human neuroblastoma-derived cell line, SH-SY5Y, and two dorsal root ganglion hybridoma cell lines, F-11 and ND7/23, using Illumina next-generation sequencing, and compared the results with native whole murine dorsal root ganglions. The gene expression profiles of these three cell lines did not resemble any specific defined dorsal root ganglion subclass. The cell lines lacked many markers for nociceptive sensory neurons, such as the Transient receptor potential V1 gene, but expressed markers for both myelinated and unmyelinated neurons. Global gene ontology analysis on whole dorsal root ganglions and cell lines showed similar enrichment of biological process terms across all samples. Conclusions This paper provides insights into the receptor repertoire expressed in common dorsal root ganglion neuron-derived cell lines compared with whole murine dorsal root ganglions, and illustrates the limits and potentials of these cell lines as tools for neuropharmacological exploration. PMID:27130590

  7. [Retinal and trabecular degeneration in glaucoma: new insights into pathogenesis and treatment].

    PubMed

    Denoyer, A; Roubeix, C; Sapienza, A; Réaux-Le Goazigo, A; Mélik-Parsadaniantz, S; Baudouin, C

    2015-04-01

    Academic and industrial research has brought new insights into the pathogenesis of glaucoma, aiming at identifying and targeting specific mechanisms to improve our current therapeutic strategy. Retinal neurodegeneration is still the main focus, whether in terms of extrinsic factors such as neurotrophin deprivation, glutamate toxicity, vascular deficiency and neuro-inflammation from glial cells, or in terms of retinal ganglion cell intrinsic sensibility to proapoptotic signals. However, glaucoma is not solely a retinal disease but also involves retinal and trabecular meshwork degeneration, extending into and/or even originating from the brain. The present review summarizes our current knowledge of key mechanisms involved in glaucoma degeneration, focusing on the direction of current research towards the future of glaucoma therapy. PMID:25659482

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

    PubMed Central

    Han, Ming-lei; Liu, Guo-hua; Guo, Jin; Yu, Shu-juan; Huang, Jing

    2016-01-01

    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 (H2O2)-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 H2O2. Western blot assay showed that in H2O2 -damaged RGC-5 cells, imipramine activated TrkB pathways through extracellular signal-regulated protein kinase/TrkB phosphorylation. TUNEL staining assay also demonstrated that imipramine ameliorated H2O2 -induced apoptosis in RGC-5 cells. Finally, TrkB-IgG intervention was able to reverse the protective effect of imipramine on H2O2 -induced RGC-5 apoptosis. Imipramine therefore protects RGCs from oxidative stress-induced apoptosis through the TrkB signaling pathway. PMID:27127489

  9. Temporary Neurotrophin Treatment Prevents Deafness-Induced Auditory Nerve Degeneration and Preserves Function.

    PubMed

    Ramekers, Dyan; Versnel, Huib; Strahl, Stefan B; Klis, Sjaak F L; Grolman, Wilko

    2015-09-01

    After substantial loss of cochlear hair cells, exogenous neurotrophins prevent degeneration of the auditory nerve. Because cochlear implantation, the current therapy for profound sensorineural hearing loss, depends on a functional nerve, application of neurotrophins is being investigated. We addressed two questions important for fundamental insight into the effects of exogenous neurotrophins on a degenerating neural system, and for translation to the clinic. First, does temporary treatment with brain-derived neurotrophic factor (BDNF) prevent nerve degeneration on the long term? Second, how does a BDNF-treated nerve respond to electrical stimulation? Deafened guinea pigs received a cochlear implant, and their cochleas were infused with BDNF for 4 weeks. Up to 8 weeks after treatment, their cochleas were analyzed histologically. Electrically evoked compound action potentials (eCAPs) were recorded using stimulation paradigms that are informative of neural survival. Spiral ganglion cell (SGC) degeneration was prevented during BDNF treatment, resulting in 1.9 times more SGCs than in deafened untreated cochleas. Importantly, SGC survival was almost complete 8 weeks after treatment cessation, when 2.6 times more SGCs were observed. In four eCAP characteristics (three involving alteration of the interphase gap of the biphasic current pulse and one involving pulse trains), we found large and statistically significant differences between normal-hearing and deaf controls. Importantly, for BDNF-treated animals, these eCAP characteristics were near normal, suggesting healthy responsiveness of BDNF-treated SGCs. In conclusion, clinically practicable short-term neurotrophin treatment is sufficient for long-term survival of SGCs, and it can restore or preserve SGC function well beyond the treatment period. Significance statement: Successful restoration of hearing in deaf subjects by means of a cochlear implant requires a healthy spiral ganglion cell population. Deafness

  10. Dual ACL Ganglion Cysts: Significance of Detailed Arthroscopy

    PubMed Central

    Singla, Amit; Nag, H. L.; Meena, Sanjay; Lohiya, Ramprakash; Agarwal, Abhinav

    2014-01-01

    Intra-articular ganglion cysts of the knee joint are rare and most frequently are an incidental finding on MRI and arthroscopy. Most of the previous studies have reported a single ganglion cyst in the knee. There have been previous reports of more than one cyst in the same knee but not in the same structure within the knee. We are reporting a case of dual ACL (anterior cruciate ligament) ganglion cysts one of which was missed on radiological examination but later detected during arthroscopy. To the best of our knowledge, no such case has been reported in the indexed English literature till date. PMID:25400962

  11. Ulnar Nerve Compression in Guyon's Canal by Ganglion Cyst.

    PubMed

    Kwak, Kyung-Woo; Kim, Min-Su; Chang, Chul-Hoon; Kim, Seong-Ho

    2011-02-01

    Compression of the ulnar nerve in Guyon's canal can result from repeated blunt trauma, fracture of the hamate's hook, and arterial thrombosis or aneurysm. In addition, conditions such as ganglia, rheumatoid arthritis and ulnar artery disease can rapidly compress the ulnar nerve in Guyon's canal. A ganglion cyst can acutely protrude or grow, which also might compress the ulnar nerve. So, clinicians should consider a ganglion cyst in Guyon's canal as a possible underlying cause of ulnar nerve compression in patients with a sudden decrease in hand strength. We believe that early decompression with removal of the ganglion is very important to promote complete recovery. PMID:21519507

  12. Ulnar Nerve Compression in Guyon's Canal by Ganglion Cyst

    PubMed Central

    Kwak, Kyung-Woo; Kim, Min-Su; Chang, Chul-Hoon

    2011-01-01

    Compression of the ulnar nerve in Guyon's canal can result from repeated blunt trauma, fracture of the hamate's hook, and arterial thrombosis or aneurysm. In addition, conditions such as ganglia, rheumatoid arthritis and ulnar artery disease can rapidly compress the ulnar nerve in Guyon's canal. A ganglion cyst can acutely protrude or grow, which also might compress the ulnar nerve. So, clinicians should consider a ganglion cyst in Guyon's canal as a possible underlying cause of ulnar nerve compression in patients with a sudden decrease in hand strength. We believe that early decompression with removal of the ganglion is very important to promote complete recovery. PMID:21519507

  13. Ganglion cyst of the posterior cruciate ligament in a child.

    PubMed

    Hameed, Shamsi Abdul; Sujir, Premjit; Naik, Monappa A; Rao, Sharath K

    2012-04-01

    Ganglion cysts are more commonly associated with the anterior cruciate ligament than the posterior cruciate ligament (PCL). A literature review showed that all reported cases of ganglion cysts to date involved adults. We report a rare case of ganglion cyst in the PCL of a four-year-old boy, and discuss its aetiology, clinical presentation, imaging features and management. Ganglion cysts of the PCL may be confused with meniscal cysts arising from tears of the posterior horn of the medial meniscus on magnetic resonance (MR) imaging. Hence, the posterior horn of the medial meniscus has to be carefully evaluated to rule out a tear. MR imaging is the method of choice to confirm diagnosis, and arthroscopic resection is a safe treatment modality even in children. PMID:22511069

  14. [Neuropsychological exploration in frontotemporal degeneration].

    PubMed

    Peña-Casanova, J; Böhm, P

    2000-01-01

    The present paper discusses the neuropsychological assessment in fronto-temporal lobe degeneration. Having established the neuroanatomical and functional basis for the discussion the major syndromes included in the concept of frontotemporal degeneration are reviewed from a neuropsychological standpoint. With reference to fronto-temporal dementia the different frontal or executive function tests and their limitations are discussed. With reference to progressive aphasia and semantic dementia we differentiate the distinct language profiles as observed in aphasia batteries and general neuropsychological tests. Reference is made to especially useful tests for the differentiation of the two syndromes from each other, as well as from other primary progressive disorders. Concluding remarks postulate a series of axis of cognitive function in fronto-temporal lobe degenerations, which exist at the functional as well as the anatomical level and along which the different syndromes evolve. PMID:10723171

  15. Volar wrist ganglion excision through the flexor carpi radialis sheath.

    PubMed

    Sawyer, Gregory A; DaSilva, Manuel F; Akelman, Edward

    2012-09-01

    Volar wrist ganglions are much less frequent than their dorsal counterparts but provide much more surgical trepidation due to their proximity to the radial artery. With the majority arising from the radiocarpal joint, we have found that entering the flexor carpi radialis sheath and accessing the ganglion through the floor of the sheath allows for a relatively safe excision of these benign hand tumors. PMID:22913995

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

    NASA Astrophysics Data System (ADS)

    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.

  17. PGC-1α Regulation of Mitochondrial Degeneration in Experimental Diabetic Neuropathy

    PubMed Central

    Choi, Joungil; Chandrasekaran, Krish; Inoue, Tatsuya; Muragundla, Anjaneyulu; Russell, James W.

    2014-01-01

    Mitochondrial degeneration is considered to play an important role in the development of diabetic peripheral neuropathy in humans. Mitochondrial degeneration and the corresponding protein regulation associated with the degeneration were studied in an animal model of diabetic neuropathy. PGC-1α and its-regulated transcription factors including TFAM and NRF1, which are master regulators of mitochondrial biogenesis, are significantly downregulated in streptozotocin diabetic dorsal root ganglion (DRG) neurons. Diabetic mice develop peripheral neuropathy, loss of mitochondria, decreased mitochondrial DNA content and increased protein oxidation. Importantly, this phenotype is exacerbated in PGC-1α (−/−) diabetic mice, which develop a more severe neuropathy with reduced mitochondrial DNA and a further increase in protein oxidation. PGC-1α (−/−) diabetic mice develop an increase in total cholesterol and triglycerides, and a decrease in TFAM and NRF1 protein levels. Loss of PGC-1α causes severe mitochondrial degeneration with vacuolization in DRG neurons, coupled with reduced state 3 and 4 respiration, reduced expression of oxidative stress response genes and an increase in protein oxidation. In contrast, overexpression of PGC-1α in cultured adult mouse neurons prevents oxidative stress associated with increased glucose levels. The study provides new insights into the role of PGC-1α in mitochondrial regeneration in peripheral neurons and suggests that therapeutic modulation of PGC-1α function may be an attractive approach for treatment of diabetic neuropathy. PMID:24423644

  18. Spatiotemporal Localization of Injury Potentials in DRG Neurons During Vincristine-Induced Axonal Degeneration

    PubMed Central

    Ravula, Surendra K.; Wang, Min S; McClain, Maxine A; Asress, Seneshaw A; Frazier, Bruno; Glass, Jonathan D

    2007-01-01

    The distal to proximal degeneration of axons, or “dying back” is a common pattern of neuropathology in many diseases of the PNS and CNS. A long-standing debate has centered on whether this pattern of neurodegeneration is due to an insult to the cell body or to the axon itself, although it is likely that mechanisms are different for specific disease entities. We have addressed this question in a model system of vincristine-induced axonal degeneration. Here, we created a novel experimental apparatus combining a microfluidic divider with a multielectrode array substrate to allow for independent monitoring of injury-induced electrical activity from dorsal root ganglion (DRG) cell bodies and axons while isolating them into their own culture microenvironments. At specified doses, exposure of the cell body to vincristine caused neither morphological neurodegeneration nor persistent hyperexcitablility. In comparison, exposure of the distal axon to the same dose of vincristine first caused a decrease in the excitability of the axon and then axonal degeneration in a dying back pattern. Additionally, exposure of axons to vincristine caused an initial period of hyperexcitability in the cell bodies, suggesting that a signal is transmitted from the distal axon to the soma during the progression of vincristine-induced axonal degeneration. These data support the proposition that vincristine has a direct neurotoxic effect on the axon. PMID:17267126

  19. Progressive Retinal Degeneration and Accumulation of Autofluorescent Lipopigments in Progranulin Deficient Mice

    PubMed Central

    Hafler, Brian P.; Klein, Zoe A.; Zhou, Z. Jimmy; Strittmatter, Stephen M.

    2014-01-01

    Prior investigations have shown that patients with neuronal ceroid lipofuscinosis (NCL) develop neurodegeneration characterized by vision loss, motor dysfunction, seizures, and often early death. Neuropathological analysis of patients with NCL shows accumulation of intracellular autofluorescent storage material, lipopigment, throughout neurons in the central nervous system including in the retina. A recent study of a sibling pair with adult onset NCL and retinal degeneration showed linkage to the region of the progranulin (GRN) locus and a homozygous mutation was demonstrated in GRN. In particular, the sibling pair with a mutation in GRN developed retinal degeneration and optic atrophy. This locus for this form of adult onset neuronal ceroid lipofuscinosis was designated neuronal ceroid lipofuscinosis-11 (CLN11). Based on these clinical observations, we wished to determine whether Grn-null mice develop accumulation of autofluorescent particles and retinal degeneration. Retinas of both wild-type and Progranulin deficient mice were examined by immunostaining and autofluorescence. Accumulation of autofluorescent material was present in Progranulin deficient mice at 12 months. Degeneration of multiple classes of neurons including photoreceptors and retinal ganglion cells was noted in mice at 12 and 18 months. Our data shows that Grn−/− mice develop degenerative pathology similar to features of human CLN11. PMID:25234724

  20. Directional summation in non-direction selective retinal ganglion cells.

    PubMed

    Abbas, Syed Y; Hamade, Khaldoun C; Yang, Ellen J; Nawy, Scott; Smith, Robert G; Pettit, Diana L

    2013-01-01

    Retinal ganglion cells receive inputs from multiple bipolar cells which must be integrated before a decision to fire is made. Theoretical studies have provided clues about how this integration is accomplished but have not directly determined the rules regulating summation of closely timed inputs along single or multiple dendrites. Here we have examined dendritic summation of multiple inputs along On ganglion cell dendrites in whole mount rat retina. We activated inputs at targeted locations by uncaging glutamate sequentially to generate apparent motion along On ganglion cell dendrites in whole mount retina. Summation was directional and dependent13 on input sequence. Input moving away from the soma (centrifugal) resulted in supralinear summation, while activation sequences moving toward the soma (centripetal) were linear. Enhanced summation for centrifugal activation was robust as it was also observed in cultured retinal ganglion cells. This directional summation was dependent on hyperpolarization activated cyclic nucleotide-gated (HCN) channels as blockade with ZD7288 eliminated directionality. A computational model confirms that activation of HCN channels can override a preference for centripetal summation expected from cell anatomy. This type of direction selectivity could play a role in coding movement similar to the axial selectivity seen in locust ganglion cells which detect looming stimuli. More generally, these results suggest that non-directional retinal ganglion cells can discriminate between input sequences independent of the retina network. PMID:23516351

  1. Directional Summation in Non-direction Selective Retinal Ganglion Cells

    PubMed Central

    Abbas, Syed Y.; Hamade, Khaldoun C.; Yang, Ellen J.; Nawy, Scott; Smith, Robert G.; Pettit, Diana L.

    2013-01-01

    Retinal ganglion cells receive inputs from multiple bipolar cells which must be integrated before a decision to fire is made. Theoretical studies have provided clues about how this integration is accomplished but have not directly determined the rules regulating summation of closely timed inputs along single or multiple dendrites. Here we have examined dendritic summation of multiple inputs along On ganglion cell dendrites in whole mount rat retina. We activated inputs at targeted locations by uncaging glutamate sequentially to generate apparent motion along On ganglion cell dendrites in whole mount retina. Summation was directional and dependent13 on input sequence. Input moving away from the soma (centrifugal) resulted in supralinear summation, while activation sequences moving toward the soma (centripetal) were linear. Enhanced summation for centrifugal activation was robust as it was also observed in cultured retinal ganglion cells. This directional summation was dependent on hyperpolarization activated cyclic nucleotide-gated (HCN) channels as blockade with ZD7288 eliminated directionality. A computational model confirms that activation of HCN channels can override a preference for centripetal summation expected from cell anatomy. This type of direction selectivity could play a role in coding movement similar to the axial selectivity seen in locust ganglion cells which detect looming stimuli. More generally, these results suggest that non-directional retinal ganglion cells can discriminate between input sequences independent of the retina network. PMID:23516351

  2. A Ganglion Cyst in the Second Lumbar Intervertebral Foramen

    PubMed Central

    Choi, Joon Hyuk; Kim, Min Su; Chang, Chul Hoon

    2011-01-01

    Ganglion cysts usually arise from the tendon sheaths and tissues around the joints. It is usually associated with degenerative arthritic changes in older people. Ganglion cyst in the spine is rare and there is no previous report on case that located in the intervertebral foramen and compressed dorsal root ganglion associated severe radiculopathy. A 29-year-old woman presented with severe left thigh pain and dysesthesia for a month. Magnetic resonance imaging revealed a dumbbell like mass in the intervertebral foramen between second and third lumbar vertebrae on the left side. The lesion was removed after exposure of the L2-L3 intervertebral foramen. The histological examination showed fragmented cystic wall-like structure composed of fibromyxoid tissue but there was no lining epithelium. A ganglion cyst may compromise lumbar dorsal root ganglion when it located in the intervertebral foramen. Although it is very rare location, ganglion cyst should be included in the differential diagnosis for intervertebral foraminal mass lesions. PMID:21607185

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

    SciTech Connect

    Walsh, C.; Polley, E.H.

    1985-03-01

    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 (/sup 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.

  4. Subparaneurial ganglion cysts of the fibular and tibial nerves: A new variant of intraneural ganglion cysts.

    PubMed

    Prasad, Nikhil K; Desy, Nicholas M; Howe, B Matthew; Amrami, Kimberly K; Spinner, Robert J

    2016-05-01

    Over the last decade, the mechanism of formation of intraneural ganglion cysts has been established through a meticulous review of clinical findings and correlation with patterns produced on magnetic resonance imaging (MRI). Pathognomonic imaging patterns distinguish these rare lesions from the more common extraneural variants in almost all cases. In this report, we present a new pattern of cyst occurrence in the subparaneurial compartment of the nerve and provide potential anatomic explanations for its pathogenesis. Using an anatomic framework of connective tissue compartments of the nerve, we reviewed 63 (56 fibular and seven tibial) intraneural ganglion cysts in the knee region evaluated at our institution and all reports with MRI in the world's literature for evidence of cyst occurrence in the subparaneurial compartment. We identified six cases (five in the common fibular nerve and one in the tibial nerve) at our institution that had MR evidence of cyst in the subparaneurial compartment with a new complex lobulated pattern. All cases had articular branch connections to the superior tibiofibular joint, which at operation were resected along with the joints. Follow-up revealed complete recovery in all instances and no clinical or radiological signs of recurrence. Three cases out of 80 in the literature exhibited the new complex lobulated MRI pattern. We present a new pattern of intraneural ganglion cyst occurrence in a potential space that surrounds peripheral nerves- the subparaneurial compartment. We believe that the unifying articular theory applies to the pathogenesis and management of these rare variants. Clin. Anat. 29:530-537, 2016. © 2015 Wiley Periodicals, Inc. PMID:26599204

  5. Heat shock proteins in the retina: Focus on HSP70 and alpha crystallins in ganglion cell survival.

    PubMed

    Piri, Natik; Kwong, Jacky M K; Gu, Lei; Caprioli, Joseph

    2016-05-01

    Heat shock proteins (HSPs) belong to a superfamily of stress proteins that are critical constituents of a complex defense mechanism that enhances cell survival under adverse environmental conditions. Cell protective roles of HSPs are related to their chaperone functions, antiapoptotic and antinecrotic effects. HSPs' anti-apoptotic and cytoprotective characteristics, their ability to protect cells from a variety of stressful stimuli, and the possibility of their pharmacological induction in cells under pathological stress make these proteins an attractive therapeutic target for various neurodegenerative diseases; these include Alzheimer's, Parkinson's, Huntington's, prion disease, and others. This review discusses the possible roles of HSPs, particularly HSP70 and small HSPs (alpha A and alpha B crystallins) in enhancing the survival of retinal ganglion cells (RGCs) in optic neuropathies such as glaucoma, which is characterized by progressive loss of vision caused by degeneration of RGCs and their axons in the optic nerve. Studies in animal models of RGC degeneration induced by ocular hypertension, optic nerve crush and axotomy show that upregulation of HSP70 expression by hyperthermia, zinc, geranyl-geranyl acetone, 17-AAG (a HSP90 inhibitor), or through transfection of retinal cells with AAV2-HSP70 effectively supports the survival of injured RGCs. RGCs survival was also stimulated by overexpression of alpha A and alpha B crystallins. These findings provide support for translating the HSP70- and alpha crystallin-based cell survival strategy into therapy to protect and rescue injured RGCs from degeneration associated with glaucomatous and other optic neuropathies. PMID:27017896

  6. Acetylation Preserves Retinal Ganglion Cell Structure and Function in a Chronic Model of Ocular Hypertension

    PubMed Central

    Alsarraf, Oday; Fan, Jie; Dahrouj, Mohammad; Chou, C. James; Yates, Phillip W.; Crosson, Craig E.

    2014-01-01

    Purpose. The current studies investigate if the histone deacetylase (HDAC) inhibitor, valproic acid (VPA), can limit retinal ganglion cell (RGC) degeneration in an ocular-hypertensive rat model. Methods. Intraocular pressure (IOP) was elevated unilaterally in Brown Norway rats by hypertonic saline injection. Rats received either vehicle or VPA (100 mg/kg) treatment for 28 days. Retinal ganglion cell function and number were assessed by pattern electroretinogram (pERG) and retrograde FluoroGold labeling. Western blotting and a fluorescence assay were used for determination of histone H3 acetylation and HDAC activity, respectively, at 3-day, 1-week, and 2-week time points. Results. Hypertonic saline injections increased IOPs by 7 to 14 mm Hg. In vehicle-treated animals, ocular hypertension resulted in a 29.1% and 39.4% decrease in pERG amplitudes at 2 and 4 weeks, respectively, and a 42.9% decrease in mean RGC density at 4 weeks. In comparison, VPA treatment yielded significant amplitude preservation at 2 and 4 weeks and showed significant RGC density preservation at 4 weeks. No significant difference in RGC densities or IOPs was measured between control eyes of vehicle- and VPA-treated rats. In ocular-hypertensive eyes, class I HDAC activity was significantly elevated within 1 week (13.3 ± 2.2%) and histone H3 acetylation was significantly reduced within 2 weeks following the induction of ocular hypertension. Conclusions. Increase in HDAC activity is a relatively early retinal event induced by elevated IOP, and suppressing HDAC activity can protect RGCs from ocular-hypertensive stress. Together these data provide a basis for developing HDAC inhibitors for the treatment of optic neuropathies. PMID:25358731

  7. Spatiotemporal aspects of pulsed electrical stimuli on the responses of rabbit retinal ganglion cells.

    PubMed

    Jensen, Ralph J; Ziv, Ofer R; Rizzo, Joseph F; Scribner, Dean; Johnson, Lee

    2009-12-01

    Implanted intraocular microelectrode arrays are being used to provide sight to individuals who are blind due to photoreceptor degeneration. It is envisioned that this retinal prosthesis will create the illusion of motion by stimulating focal areas of the retina in a sequential fashion through neighboring electrodes, much like the rapid succession of still images in movies and computer animation gives rise to apparent motion. Using a high-density microelectrode array, we examined the extracellularly recorded responses of rabbit retinal ganglion cells to a bar-shaped electrode array that was stepped at 50 microm increments at different rates across the retina and compared these responses to the responses generated to a similarly shaped light stimulus that was stepped across the retina. When the retina was stimulated at 1 step/s, retinal ganglion cells gave robust bursts of action potentials to both the electrode array and the light stimulus. The responses to the 'moving' electrode array decreased progressively with increasing stepping frequency. At 16 steps/s (highest frequency tested), the number of spikes per sweep and the number of bursts per sweep were reduced 75% and 67% respectively. In contrast, when the retina was stimulated at 16 steps/s with the 'moving' light stimulus, the number of spikes per sweep and the number of bursts per sweep were reduced only 43% and 25% respectively. These findings suggest that simple translation of object motion to sequential stimulation through neighboring electrodes may not be the best way to convey the perception of object motion in a patient with a retinal prosthesis. PMID:19766116

  8. Macular Degeneration - Multiple Languages: MedlinePlus

    MedlinePlus

    ... Are Here: Home → Multiple Languages → All Health Topics → Macular Degeneration URL of this page: https://www.nlm.nih. ... V W XYZ List of All Topics All Macular Degeneration - Multiple Languages To use the sharing features on ...

  9. Ataxias and Cerebellar or Spinocerebellar Degeneration

    MedlinePlus

    ... Awards Enhancing Diversity Find People About NINDS NINDS Ataxias and Cerebellar or Spinocerebellar Degeneration Information Page Synonym(s): ... Publications and Information Publicaciones en Español What are Ataxias and Cerebellar or Spinocerebellar Degeneration? Ataxia often occurs ...

  10. Sphenopalatine Ganglion Stimulation in Neurovascular Headaches.

    PubMed

    Schoenen, Jean

    2015-01-01

    The interest for the sphenopalatine ganglion (SPG) in neurovascular headaches dates back to 1908 when Sluder presented his work on the role of the SPG in 'nasal headaches', which are now part of the trigeminal autonomic cephalalgias and cluster headache (ICHD-III-beta). Since then various interventions with blocking or lesional properties have targeted the SPG (transnasal injection of lidocaine and other agents, alcohol or steroid injections, radiofrequency lesions, or even ganglionectomy); success rates vary, but benefit is usually transient. Here we briefly review some anatomophysiological characteristics of the SPG and hypotheses about its pathophysiological role in neurovascular headaches before describing recent therapeutic results obtained with electrical stimulation of the SPG. Based on results of a prospective randomized controlled study, SPG stimulation appears to be an effective treatment option for patients with chronic cluster headaches; efficacy data indicate that acute electrical stimulation of the SPG provides significant attack pain relief and in many cases pain freedom compared to sham stimulation. Moreover, in some patients SPG stimulation has been associated with a significant and clinically meaningful reduction in cluster headache attack frequency; this preventive effect of SPG stimulation warrants further investigation. For migraine attacks, the outcome of a proof-of-concept study using a temporary electrode implanted in the pterygopalatine fossa was less encouraging; however, an ongoing multicenter trial is evaluating the efficacy of long-term SPG stimulation against sham stimulation for acute and preventive treatment in patients with frequent migraine. PMID:26394372

  11. Polymodal Sensory Integration in Retinal Ganglion Cells.

    PubMed

    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. PMID:26427477

  12. Human pelvic extramural ganglion cells: a semiquantitative and immunohistochemical study.

    PubMed

    Imai, Kanoko; Furuya, Kenichi; Kawada, Michihiro; Kinugasa, Yusuke; Omote, Kiichi; Namiki, Akiyoshi; Uchiyama, Eiichi; Murakami, Gen

    2006-12-01

    In pelvic surgery, much attention is paid to nerve bundles but not to ganglion cells. Using serial section histology of 14 postmortem-treated hemipelvis (eight males, six females; mean, 79 years old), we examined the population number, distribution, and tyrosine hydroxylase-immunoreactivity (TH-IR; suggesting sympathetic neurons) of extramural pelvic ganglion cells. All pelvic ganglion cells were uniformly sized (25-30 microm) contrasting with small intramural rectal neurons. Abundant ganglion cells (30,000-140,000 unilaterally) existed not only along the pelvic viscera except for the rectum, but also along the hypogastric nerve, pelvic splanchnic nerve, pelvic plexus, and associated branches excluding those within the mesorectum. The intrapelvic ganglion cells outside the sympathetic trunk did not form macroscopically identifiable ganglia, but made small clusters (0.1-2.0 mm of maximum diameter) or were diffusely scattered within nerve bundles. More than half of these cells appeared TH-IR positive, although the positive/negative proportion differed between nerves and specimens. Greater numbers of ganglion cells were found in dorsosuperior sites (e.g., around the seminal vesicle) rather than in ventroinferior sites (e.g., along the urethra) in males, and vice versa in females. However, in total cell numbers, interindividual variations were evident rather than intergender difference. Due to significant interindividual variations in cell number, differences are likely to exist between patients in "resistance" to surgical stresses. We hypothesized that pelvic ganglion cells are liable to be damaged due to drying along the surgical margin, hypoxia in venous bleeding, pressure from surgical retractors, extension stress with taping and excess traction and/or direct injury with electrical scalpels. PMID:17033734

  13. Differentiation of human pluripotent stem cells into Medial Ganglionic Eminence vs. Caudal Ganglionic Eminence cells.

    PubMed

    Ahn, Sandra; Kim, Tae-Gon; Kim, Kwang-Soo; Chung, Sangmi

    2016-05-15

    Human pluripotent stem cells (PSCs) represent an opportunity to study human development in vitro, to model diseases in a dish, to screen drugs as well as to provide an unlimited and ethically unimpeded source of therapeutic cells. Cortical GABAergic interneurons, which are generated from Medial Ganglionic Eminence (MGE) cells and Caudal Ganglionic Eminence (CGE) cells during embryonic development, regulate cortical neural networks by providing inhibitory inputs. Their malfunction, resulting in failure to intricately regulate neural circuit balance, has been implicated in brain diseases, such as schizophrenia, autism and epilepsy. In this study, using combinatorial and temporal modulation of developmentally relevant dorsoventral and rostrocaudal signaling pathways, we efficiently generated MGE cells vs. CGE cells from human PSCs, which predominantly generate Parvalbumin-expressing or Somatostatin-expressing interneurons vs. Calretinin-expressing interneurons, respectively. Efficient generation of specific differentiated progenies of hPSCs as shown in this study will be a pivotal step to realize the full potential of hPSCs for regenerative medicine, developmental studies, disease modeling, bioassay, and drug screening. PMID:26364591

  14. 3-acetylpyridine-induced degeneration in the adult ascidian neural complex: Reactive and regenerative changes in glia and blood cells.

    PubMed

    Medina, Bianca N S P; Santos de Abreu, Isadora; Cavalcante, Leny A; Silva, Wagner A B; da Fonseca, Rodrigo N; Allodi, Silvana; de Barros, Cintia M

    2015-08-01

    Ascidians are interesting neurobiological models because of their evolutionary position as a sister-group of vertebrates and the high regenerative capacity of their central nervous system (CNS). We investigated the degeneration and regeneration of the cerebral ganglion complex of the ascidian Styela plicata following injection of the niacinamide antagonist 3-acetylpyridine (3AP), described as targeting the CNS of several vertebrates. For the analysis and establishment of a new model in ascidians, the ganglion complex was dissected and prepared for transmission electron microscopy (TEM), routine light microscopy (LM), immunohistochemistry and Western blotting, 1 or 10 days after injection of 3AP. The siphon stimulation test (SST) was used to quantify the functional response. One day after the injection of 3AP, CNS degeneration and recruitment of a non-neural cell type to the site of injury was observed by both TEM and LM. Furthermore, weaker immunohistochemical reactions for astrocytic glial fibrillary acidic protein (GFAP) and neuronal βIII-tubulin were observed. In contrast, the expression of caspase-3, a protein involved in the apoptotic pathway, and the glycoprotein CD34, a marker for hematopoietic stem cells, increased. Ten days after the injection of 3AP, the expression of markers tended toward the original condition. The SST revealed attenuation and subsequent recovery of the reflexes from 1 to 10 days after 3AP. Therefore, we have developed a new method to study ascidian neural degeneration and regeneration, and identified the decreased expression of GFAP and recruitment of blood stem cells to the damaged ganglion as reasons for the success of neuroregeneration in ascidians. PMID:25484282

  15. Progressive Degeneration of Retinal and Superior Collicular Functions in Mice With Sustained Ocular Hypertension

    PubMed Central

    Chen, Hui; Zhao, Yan; Liu, Mingna; Feng, Liang; Puyang, Zhen; Yi, Ji; Liang, Peiji; Zhang, Hao F.; Cang, Jianhua; Troy, John B.; Liu, Xiaorong

    2015-01-01

    Purpose. We investigated the progressive degeneration of retinal and superior collicular functions in a mouse model of sustained ocular hypertension. Methods. Focal laser illumination and injection of polystyrene microbeads were used to induce chronic ocular hypertension. Retinal ganglion cell (RGC) loss was characterized by in vivo optical coherence tomography (OCT) and immunohistochemistry. Retinal dysfunction was also monitored by the full-field ERG. Retinal ganglion cell light responses were recorded using a 256-channel multielectrode array (MEA), and RGC subtypes were characterized by noncentered spike-triggered covariance (STC-NC) analysis. Single-unit extracellular recordings from superficial layers of the superior colliculus (SC) were performed to examine the receptive field (RF) properties of SC neurons. Results. The elevation of intraocular pressure (IOP) lasted 4 months in mice treated with a combination of laser photocoagulation and microbead injection. Progressive RGC loss and functional degeneration were confirmed in ocular hypertensive (OHT) mice. These mice had fewer visually responsive RGCs than controls. Using the STC-NC analysis, we classified RGCs into ON, OFF, and ON-OFF functional subtypes. We showed that ON and OFF RGCs were more susceptible to the IOP elevation than ON-OFF RGCs. Furthermore, SC neurons of OHT mice had weakened responses to visual stimulation and exhibited mismatched ON and OFF subfields and irregular RF structure. Conclusions. We demonstrated that the functional degeneration of RGCs is subtype-dependent and that the ON and OFF pathways from the retina to the SC were disrupted. Our study provides a foundation to investigate the mechanisms underlying the progressive vision loss in experimental glaucoma. PMID:25722210

  16. Overexpression of X-Linked Inhibitor of Apoptotic Protein (XIAP) reduces age-related neuronal degeneration in the mouse cochlea.

    PubMed

    Ruan, Q; Zeng, S; Liu, A; Chen, Z; Yu, Z; Zhang, R; He, J; Bance, M; Robertson, G; Yin, S; Wang, J

    2014-11-01

    Previously, we showed that age-related hearing loss (AHL) was delayed in C57BL6 mice overexpressing X-Linked Inhibitor of Apoptotic Protein (XIAP), and the delayed AHL was associated with attenuated hair cell (HC) loss in XIAP-overexpressing mice. Similar to other reports, the HC loss in aged mice was restricted to the basal turn in this previous study, and occurred slightly at the apical end of the cochlea, showing considerably less spread than the frequency region of hearing loss. In the present study, we examined whether and how AHL is related to the degeneration of neuronal innervation of the cochlea and whether the overexpression of XIAP exerts a protective effect against age-related degeneration in both afferent and efferent cochlear neurites. In contrast to HC loss, degeneration of both afferent and efferent neurites spread to the middle turns of the cochlea. Moreover, XIAP-overexpressing mice lost fewer HC afferent dendrites and efferent axons, as well as fewer spiral ganglion neurons between 3 and 14 months of age in comparison with wild-type littermates. The results suggest that age-related degeneration of cochlear neurites may be independent of HC loss. Further, the inhibition of apoptosis by XIAP appears to reduce degeneration of both afferent and efferent cochlear neurites. PMID:25142138

  17. Overexpression of X-Linked Inhibitor of Apoptotic Protein (XIAP) Reduces Age-related Neuronal Degeneration in the Mouse Cochlea

    PubMed Central

    Ruan, Qingwei; Zeng, Shan; Liu, Aiguo; Chen, Zhengnong; Yu, Zhuowei; Zhang, Ruxin; He, jingchun; Bance, Manohar; Robertson, George; Yin, Shankai; Wang, Jian

    2016-01-01

    Previously, we showed that age-related hearing loss (AHL) was delayed in C57BL6 mice overexpressing X-Linked Inhibitor of Apoptotic Protein (XIAP), and the delayed AHL was associated with attenuated hair cell (HC) loss in XIAP-overexpressing mice. Similar to other reports, the HC loss in aged mice was restricted to the basal turn in this previous study, and occurred slightly at the apical end of the cochlea, showing considerably less spread than the frequency region of hearing loss. In the present study, we examined whether and how AHL is related to the degeneration of neuronal innervation of the cochlea and if the overexpression of XIAP exerts a protective effect against age-related degeneration in both afferent and efferent cochlear neurites. In contrast to HC loss, degeneration of both afferent and efferent neurites spread to the middle turns of the cochlea. Moreover, XIAP-overexpressing mice lost fewer HC afferent dendrites and efferent axons, as well as fewer spiral ganglion neurons (SGNs) between 3– 14 months of age in comparison to wild-type littermates. The results suggest that age-related degeneration of cochlear neurites may be independent of HC loss. Further, the inhibition of apoptosis by XIAP appears to reduce degeneration of both afferent and efferent cochlear neurites. PMID:25142138

  18. Imaging of retinal ganglion cells in glaucoma: pitfalls and challenges.

    PubMed

    Werkmeister, R M; Cherecheanu, A Popa; Garhofer, G; Schmidl, D; Schmetterer, L

    2013-08-01

    Imaging has gained a key role in modern glaucoma management. Traditionally, interest was directed toward the appearance of the optic nerve head and the retinal nerve fiber layer. With the improvement of the resolution of optical coherence tomography, the ganglion cell complex has also become routinely accessible in the clinic. Further advances have been made in understanding the structure-function relationship in glaucoma. Nevertheless, direct imaging of the retinal ganglion cells in glaucoma would be advantageous. With the currently used techniques, this goal cannot be achieved, because the transversal resolution is limited by aberrations of the eye. The use of adaptive optics has significantly improved transversal resolution, and the imaging of several cell types including cones and astrocytes has become possible. Imaging of retinal ganglion cells, however, still remains a problem, because of the transparency of these cells. However, the visualization of retinal ganglion cells and their dendrites has been achieved in animal models. Furthermore, attempts have been made to visualize the apoptosis of retinal ganglion cells in vivo. Implementation of these techniques in clinical practice will probably improve glaucoma care and facilitate the development of neuroprotective strategies. PMID:23512142

  19. Ganglion and “Dendrite” Populations in EAS Ears

    PubMed Central

    Rask-Andersen, Helge; Liu, Wei; Linthicum, Fred H

    2010-01-01

    Background/Aims EAS technique combines electric and acoustic stimulation in the same ear and utilizes both low frequency acoustic hearing and electric stimulation of preserved neurons. We present data of ganglion cell and dendrite populations in ears from normal individuals and those suffered from adult-onset hereditary progressive hearing loss with various residual low tone hearing. Some of these were potential candidates for EAS surgery. The data may give us information about the neuro-anatomic situation in EAS ears. Methods Dendrites and ganglion cells were calculated and audio-cytocochleograms constructed. The temporal bones were from the collection at the House Ear Institute in Los Angeles, USA. Normal human anatomy, based on surgical specimens, is presented. Results IHCs and OHCs, supporting cells, ganglion cells and dendrites were preserved in the apical region. In the mid-frequency region, around 1 kHz, the OC with inner and outer hair cells were often conserved while in the lower basal turn, representing frequencies above 3 kHz, OC was atrophic and replaced by thin cells. Despite loss of hair cells and lamina fibers ganglion cells were present even after 28 years duration of deafness. Conclusions Conditions with profound SNHL with preserved low tone hearing may have several causes and the pathology may vary accordingly. In our patients with progressive adult-onset SNHL (amalgamated into “presbyacusis”) neurons were conserved even after long duration of deafness. These spiral ganglion cells may be excellent targets for electric stimulation using EAS technique. PMID:19955718

  20. Assessment of retinal ganglion cell damage in glaucomatous optic neuropathy: Axon transport, injury and soma loss.

    PubMed

    Nuschke, Andrea C; Farrell, Spring R; Levesque, Julie M; Chauhan, Balwantray C

    2015-12-01

    Glaucoma is a disease characterized by progressive axonal pathology and death of retinal ganglion cells (RGCs), which causes structural changes in the optic nerve head and irreversible vision loss. Several experimental models of glaucomatous optic neuropathy (GON) have been developed, primarily in non-human primates and, more recently and commonly, in rodents. These models provide important research tools to study the mechanisms underlying glaucomatous damage. Moreover, experimental GON provides the ability to quantify and monitor risk factors leading to RGC loss such as the level of intraocular pressure, axonal health and the RGC population. Using these experimental models we are able to gain a better understanding of GON, which allows for the development of potential neuroprotective strategies. Here we review the advantages and disadvantages of the relevant and most often utilized methods for evaluating axonal degeneration and RGC loss in GON. Axonal pathology in GON includes functional disruption of axonal transport (AT) and structural degeneration. Horseradish peroxidase (HRP), rhodamine-B-isothiocyanate (RITC) and cholera toxin-B (CTB) fluorescent conjugates have proven to be effective reporters of AT. Also, immunohistochemistry (IHC) for endogenous AT-associated proteins is often used as an indicator of AT function. Similarly, structural degeneration of axons in GON can be investigated via changes in the activity and expression of key axonal enzymes and structural proteins. Assessment of axonal degeneration can be measured by direct quantification of axons, qualitative grading, or a combination of both methods. RGC loss is the most frequently quantified variable in studies of experimental GON. Retrograde tracers can be used to quantify RGC populations in rodents via application to the superior colliculus (SC). In addition, in situ IHC for RGC-specific proteins is a common method of RGC quantification used in many studies. Recently, transgenic mouse models

  1. Nutritional supplements for macular degeneration.

    PubMed

    2006-02-01

    Age-related macular degeneration is the commonest cause of blindness in developed countries and the third most common worldwide. Each year in the UK, around 17,000 people become blind or partially sighted as a result of this condition, and its prevalence is likely to increase with an ageing population. Laser therapy and rarely surgery, can slow disease progression in a minority of patients but is unlikely to restore lost vision. A wide range of nutritional supplements are now on sale with promotional claims that they improve eye health. While some specialists recommend their use to patients with advanced disease, these supplements are also increasingly promoted to people with early or no signs of disease. Consequently, GPs come under pressure from patients to recommend, or even prescribe, a nutritional supplement. Here we examine the evidence for nutritional supplements in the management of age-related macular degeneration and consider which, if any, can be recommended. PMID:16550811

  2. Frequency Responses of Rat Retinal Ganglion Cells

    PubMed Central

    Cloherty, Shaun L.; Hung, Yu-Shan; Kameneva, Tatiana; Ibbotson, Michael R.

    2016-01-01

    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. PMID:27341669

  3. Retinal Ganglion Cell Atrophy in Homonymous Hemianopia due to Acquired Occipital Lesions Observed Using Cirrus High-Definition-OCT

    PubMed Central

    Yamashita, Tsutomu; Miki, Atsushi; Goto, Katsutoshi; Araki, Syunsuke; Takizawa, Go; Ieki, Yoshiaki; Kiryu, Junichi; Tabuchi, Akio; Iguchi, Yasuyuki; Kimura, Kazumi; Yagita, Yoshiki

    2016-01-01

    Purpose. To report a reduction in macular ganglion cell layer and inner plexiform layer (GCL+IPL) thickness and circumpapillary retinal nerve fiber layer (cpRNFL) thickness using spectral-domain optical coherence tomography in patients with homonymous hemianopia due to posterior cerebral artery (PCA) stroke. Methods. Seven patients with PCA stroke were examined using Cirrus high-definition-OCT. The GCL+IPL thicknesses were divided into the hemianopic and unaffected sides. The relationship between the time after stroke and the GCL+IPL thicknesses in the hemianopic side was evaluated. Results. The average thicknesses of the GCL+IPL were 64.6 and 82.0 μm on the hemianopic and unaffected sides, respectively, and the measurement was significantly thinner on the former side (p = 0.018). A regression analysis revealed a negative linear relationship (R2 = 0.574, p = 0.049) between the time after stoke and the GCL+IPL thicknesses on the hemianopic side. The supratemporal and inferotemporal cpRNFL thicknesses in the eyes ipsilateral to the stroke showed a significant reduction. Conclusion. Our findings confirmed our previous observations that the degeneration of retinal ganglion cells can occur after PCA stroke. GCL+IPL thinning was demonstrated in the hemiretinae corresponding to the affected hemifields. Also, it is suggested that the retinal changes observed are progressive. PMID:27274865

  4. Radial keratotomy associated endothelial degeneration

    PubMed Central

    Moshirfar, Majid; Ollerton, Andrew; Semnani, Rodmehr T; Hsu, Maylon

    2012-01-01

    Purpose To describe the presentation and clinical course of eyes with a history of radial keratotomy (RK) and varying degrees of endothelial degeneration. Methods Retrospective case series were used. Results Thirteen eyes (seven patients) were identified with clinical findings of significant guttata and a prior history of RK. The mean age of presentation for cornea evaluation was 54.3 years (range: 38–72 years), averaging 18.7 years (range: 11–33 years) after RK. The presentation of guttata varied in degree from moderate to severe. Best corrected visual acuity (BCVA) ranged from 20/25 to 20/80. All patients had a history of bilateral RK, except one patient who did not develop any guttata in the eye without prior RK. No patients reported a family history of Fuch’s Dystrophy. One patient underwent a penetrating keratoplasty in one eye and a Descemet’s stripping automated endothelial keratoplasty (DSAEK) in the other eye. Conclusions RK may induce a spectrum of endothelial degeneration. In elderly patients, the findings of guttata may signify comorbid Fuch’s dystrophy in which RK incisions could potentially hasten endothelial decomposition. In these select patients with stable cornea topography and prior RK, DSAEK may successfully treat RK endothelial degeneration. PMID:22347792

  5. Light scattering of degenerate fermions

    NASA Astrophysics Data System (ADS)

    Aubin, S.; Leblanc, L. J.; Myrskog, S.; Extavour, M. H. T.; McKay, D.; Stummer, A.; Thywissen, J. H.

    2006-05-01

    We report on progress in measuring the suppression of resonant light scattering in a gas of degenerate fermions. A gas of trapped degenerate fermions is expected to exhibit narrower optical linewidths and longer excited state lifetimes than single atoms when the Fermi energy is larger than the photon recoil energy [1-3]. In this case, the number of available states into which a scattered atom can recoil is significantly reduced due to the filling of the Fermi sea. We produce a degenerate gas of 4x10^4 ultra-cold fermionic ^40K atoms by sympathetic cooling with bosonic ^87Rb in a micro-magnetic chip trap. The atoms can then be loaded into a tight dipole trap just above the surface of the chip and probed with a near resonance laser pulse. [1] Th. Busch, J. R. Anglin, J. I. Cirac, and P. Zoller, Europhys. Lett. 44, 1 (1998). [2] B. DeMarco and D. S. Jin, Phys. Rev. A 58, R4267 (1998). [3] J. Javanainen and J. Ruostekosky, Phys. Rev. A 52, 3033 (1995). Work supported by NSERC, CFI, OIT, Research Corporation, and PRO.

  6. General pathophysiology in retinal degeneration.

    PubMed

    Wert, Katherine J; Lin, Jonathan H; Tsang, Stephen H

    2014-01-01

    Retinal degeneration, including that seen in age-related macular degeneration and retinitis pigmentosa (RP), is the most common form of neural degenerative disease in the world. There is great genetic and allelic heterogeneity of the various retinal dystrophies. Classifications of these diseases can be ambiguous, as there are similar clinical presentations in retinal degenerations arising from different genetic mechanisms. As would be expected, alterations in the activity of the phototransduction cascade, such as changes affecting the renewal and shedding of the photoreceptor OS, visual transduction, and/or retinol metabolism have a great impact on the health of the retina. Mutations within any of the molecules responsible for these visual processes cause several types of retinal and retinal pigment epithelium degenerative diseases. Apoptosis has been implicated in the rod cell loss seen in a mouse model of RP, but the precise mechanisms that connect the activation of these pathways to the loss of phosphodiesterase (PDE6β) function has yet to be defined. Additionally, the activation of apoptosis by CCAAT/-enhancer-binding protein homologous protein (CHOP), after activation of the unfolded protein response pathway, may be responsible for cell death, although the mechanism remains unknown. However, the mechanisms of cell death after loss of function of PDE6, which is a commonly studied mammalian model in research, may be generalizable to loss of function of different key proteins involved in the phototransduction cascade. PMID:24732759

  7. General Pathophysiology in Retinal Degeneration

    PubMed Central

    Wert, Katherine J.; Lin, Jonathan H.; Tsang, Stephen H.

    2015-01-01

    Retinal degeneration, including that seen in age-related macular degeneration and retinitis pigmentosa (RP), is the most common form of neural degenerative disease in the world. There is great genetic and allelic heterogeneity of the various retinal dystrophies. Classifications of these diseases can be ambiguous, as there are similar clinical presentations in retinal degenerations arising from different genetic mechanisms. As would be expected, alterations in the activity of the phototransduction cascade, such as changes affecting the renewal and shedding of the photoreceptor OS, visual transduction, and/ or retinol metabolism have a great impact on the health of the retina. Mutations within any of the molecules responsible for these visual processes cause several types of retinal and retinal pigment epithelium degenerative diseases. Apoptosis has been implicated in the rod cell loss seen in a mouse model of RP, but the precise mechanisms that connect the activation of these pathways to the loss of phosphodiesterase (PDE6β) function has yet to be defined. Additionally, the activation of apoptosis by CCAAT/-enhancer-binding protein homologous protein (CHOP), after activation of the unfolded protein response pathway, may be responsible for cell death, although the mechanism remains unknown. However, the mechanisms of cell death after loss of function of PDE6, which is a commonly studied mammalian model in research, may be generalizable to loss of function of different key proteins involved in the phototransduction cascade. PMID:24732759

  8. The degeneration of Y chromosomes.

    PubMed

    Charlesworth, B; Charlesworth, D

    2000-11-29

    Y chromosomes are genetically degenerate, having lost most of the active genes that were present in their ancestors. The causes of this degeneration have attracted much attention from evolutionary theorists. Four major theories are reviewed here: Muller's ratchet, background selection, the Hill Robertson effect with weak selection, and the 'hitchhiking' of deleterious alleles by favourable mutations. All of these involve a reduction in effective population size as a result of selective events occurring in a non-recombining genome, and the consequent weakening of the efficacy of selection. We review the consequences of these processes for patterns of molecular evolution and variation at loci on Y chromosomes, and discuss the results of empirical studies of these patterns for some evolving Y-chromosome and neo-Y-chromosome systems. These results suggest that the effective population sizes of evolving Y or neo-Y chromosomes are severely reduced, as expected if some or all of the hypothesized processes leading to degeneration are operative. It is, however, currently unclear which of the various processes is most important; some directions for future work to help to resolve this question are discussed. PMID:11127901

  9. Expression of Aquaporin-6 in Rat Retinal Ganglion Cells.

    PubMed

    Jang, Sun Young; Lee, Eung Suk; Ohn, Young-Hoon; Park, Tae Kwann

    2016-08-01

    Several aquaporins (AQPs) have been identified to be present in the eyes, and it has been suggested that they are involved in the movement of water and small solutes. AQP6, which has low water permeability and transports mainly anions, was recently discovered in the eyes. In the present study, we investigate the localization of AQP6 in the rat retina and show that AQP6 is selectively localized to the ganglion cell layer and the outer plexiform layer. Along with the gradual decrease in retinal ganglion cells after a crushing injury of optic nerve, immunofluorescence signals of AQP6 gradually decreased. Confocal microscope images confirmed AQP6 expression in retinal ganglion cells and Müller cells in vitro. Therefore, AQP6 might participate in water and anion transport in these cells. PMID:26526333

  10. Oil ganglion dynamics in flow through porous media

    NASA Astrophysics Data System (ADS)

    Ng, K. M.

    1980-12-01

    A model is formulated to study the transient behavior of oil ganglion populations during immiscible displacement in oil recovery processes. The model is composed of three components: a suitable model for granular porous media; a stochastic simulation method capable of predicting the fate of solitary ganglia and two coupled population balance equations for studying the dynamics of oil ganglion populations. The porous medium model proposed is a network of interconnected unit cells of the constricted tube type. The permeability of this model is determined by both the statistical analysis the network analysis. It is demonstrated that fluids in different portions of a porous medium interact with one another. Two methods are used in the simulation of the motion of solitary ganglion. It is found that the velocity of an oil blob decreases as its viscosity increases.

  11. Dissociated ciliary ganglion neurons in vitro: survival and synapse formation.

    PubMed Central

    Nishi, R; Berg, D K

    1977-01-01

    Normally, about half of the ciliary ganglion neurons in 8-day-old chick embryos die before day 14 in ovo. However, when dissociated ciliary ganglion neurons were prepared from either 8- or 14-day-old embryos and grown in cell culture with skeletal myotubes, essentially all of the neurons survived for at least 3 weeks. Many of the neurons formed functional synapses on myotubes under these conditions; some neuromuscular synapses could be detected as early as 20 hr after addition of the ganglion cells to muscle cultures. In contrast, most neurons from 8-day embryos survived for only a few days when grown alone on either polyornithine- or collagen-coated dishes. These results suggest that neurons destined to die in ovo can be rescued when grown in cell culture with myotubes and that under these conditions the neurons develop and express differentiated properties. Images PMID:270756

  12. Ganglion Cyst Associated with Triangular Fibrocartilage Complex Tear That Caused Ulnar Nerve Compression

    PubMed Central

    Cinar, Can; Tasdelen, Neslihan

    2015-01-01

    Summary: Ganglions are the most frequently seen soft-tissue tumors in the hand. Nerve compression due to ganglion cysts at the wrist is rare. We report 2 ganglion cysts arising from triangular fibrocartilage complex, one of which caused ulnar nerve compression proximal to the Guyon's canal, leading to ulnar neuropathy. Ganglion cysts seem unimportant, and many surgeons refrain from performing a general hand examination. PMID:25878929

  13. Ganglion cyst associated with triangular fibrocartilage complex tear that caused ulnar nerve compression.

    PubMed

    Bingol, Ugur Anil; Cinar, Can; Tasdelen, Neslihan

    2015-03-01

    Ganglions are the most frequently seen soft-tissue tumors in the hand. Nerve compression due to ganglion cysts at the wrist is rare. We report 2 ganglion cysts arising from triangular fibrocartilage complex, one of which caused ulnar nerve compression proximal to the Guyon's canal, leading to ulnar neuropathy. Ganglion cysts seem unimportant, and many surgeons refrain from performing a general hand examination. PMID:25878929

  14. Variable phenotypic expressivity in inbred retinal degeneration mouse lines: A comparative study of C3H/HeOu and FVB/N rd1 mice

    PubMed Central

    van Wyk, Michiel; Schneider, Sabine

    2015-01-01

    Purpose Recent advances in optogenetics and gene therapy have led to promising new treatment strategies for blindness caused by retinal photoreceptor loss. Preclinical studies often rely on the retinal degeneration 1 (rd1 or Pde6brd1) retinitis pigmentosa (RP) mouse model. The rd1 founder mutation is present in more than 100 actively used mouse lines. Since secondary genetic traits are well-known to modify the phenotypic progression of photoreceptor degeneration in animal models and human patients with RP, negligence of the genetic background in the rd1 mouse model is unwarranted. Moreover, the success of various potential therapies, including optogenetic gene therapy and prosthetic implants, depends on the progress of retinal degeneration, which might differ between rd1 mice. To examine the prospect of phenotypic expressivity in the rd1 mouse model, we compared the progress of retinal degeneration in two common rd1 lines, C3H/HeOu and FVB/N. Methods We followed retinal degeneration over 24 weeks in FVB/N, C3H/HeOu, and congenic Pde6b+ seeing mouse lines, using a range of experimental techniques including extracellular recordings from retinal ganglion cells, PCR quantification of cone opsin and Pde6b transcripts, in vivo flash electroretinogram (ERG), and behavioral optokinetic reflex (OKR) recordings. Results We demonstrated a substantial difference in the speed of retinal degeneration and accompanying loss of visual function between the two rd1 lines. Photoreceptor degeneration and loss of vision were faster with an earlier onset in the FVB/N mice compared to C3H/HeOu mice, whereas the performance of the Pde6b+ mice did not differ significantly in any of the tests. By postnatal week 4, the FVB/N mice expressed significantly less cone opsin and Pde6b mRNA and had neither ERG nor OKR responses. At 12 weeks of age, the retinal ganglion cells of the FVB/N mice had lost all light responses. In contrast, 4-week-old C3H/HeOu mice still had ERG and OKR responses, and we

  15. An atypical presentation of a flexor intratendinous ganglion of the hand.

    PubMed

    Chia, Dawn Sinn Yii; Kong, Jun Cheong; Teoh, Lam Chuan

    2015-03-01

    Intratendinous ganglions of the hand are rare. We report an unusual case of a ganglion arising within the flexor tendon in the hand. The intratendinous ganglion arose from the flexor digitorium profundus tendon of the little finger, causing flexion deformity of the finger. PMID:24051457

  16. Direct Comparison of Rat- and Human-Derived Ganglionic Eminence Tissue Grafts on Motor Function.

    PubMed

    Lelos, Mariah J; Roberton, Victoria H; Vinh, Ngoc-Nga; Harrison, Carl; Eriksen, Peter; Torres, Eduardo M; Clinch, Susanne P; Rosser, Anne E; Dunnett, Stephen B

    2016-01-01

    Huntington's disease (HD) is a debilitating, genetically inherited neurodegenerative disorder that results in early loss of medium spiny neurons from the striatum and subsequent degeneration of cortical and other subcortical brain regions. Behavioral changes manifest as a range of motor, cognitive, and neuropsychiatric impairments. It has been established that replacement of the degenerated medium spiny neurons with rat-derived fetal whole ganglionic eminence (rWGE) tissue can alleviate motor and cognitive deficits in preclinical rodent models of HD. However, clinical application of this cell replacement therapy requires the use of human-derived (hWGE), not rWGE, tissue. Despite this, little is currently known about the functional efficacy of hWGE. The aim of this study was to directly compare the ability of the gold standard rWGE grafts, against the clinically relevant hWGE grafts, on a range of behavioral tests of motor function. Lister hooded rats either remained as unoperated controls or received unilateral excitotoxic lesions of the lateral neostriatum. Subsets of lesioned rats then received transplants of either rWGE or hWGE primary fetal tissue into the lateral striatum. All rats were tested postlesion and postgraft on the following tests of motor function: staircase test, apomorphine-induced rotation, cylinder test, adjusting steps test, and vibrissae-evoked touch test. At 21 weeks postgraft, brain tissue was taken for histological analysis. The results revealed comparable improvements in apomorphine-induced rotational bias and the vibrissae test, despite larger graft volumes in the hWGE cohort. hWGE grafts, but not rWGE grafts, stabilized behavioral performance on the adjusting steps test. These results have implications for clinical application of cell replacement therapies, as well as providing a foundation for the development of stem cell-derived cell therapy products. PMID:26727032

  17. Spiral ganglion neuron survival and function in the deafened cochlea following chronic neurotrophic treatment

    PubMed Central

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

    2011-01-01

    Cochlear implants electrically stimulate residual spiral ganglion neurons (SGNs) to provide auditory cues for the severe-profoundly deaf. However, SGNs gradually degenerate following cochlear hair cell loss, leaving fewer neurons available for stimulation. Providing an exogenous supply of neurotrophins (NTs) has been shown to prevent SGN degeneration, and when combined with chronic intracochlear electrical stimulation (ES) following a short period of deafness (5 days), may also promote the formation of new neurons. The present study assessed the histopathological response of guinea pig cochleae treated with NTs (brain-derived neurotrophic factor and neurotrophin-3) with and without ES over a four week period, initiated two-weeks after deafening. Results were compared to both NT alone and artificial perilymph (AP) treated animals. AP/ES treated animals exhibited no evidence of SGN rescue compared with untreated deafened controls. In contrast, NT administration showed a significant SGN rescue effect in the lower and middle cochlear turns (two-way ANOVA, p < 0.05) compared with AP-treated control animals. ES in combination with NT did not enhance SGN survival compared with NT alone. SGN function was assessed by measuring electrically-evoked auditory brainstem response (EABR) thresholds. EABR thresholds following NT treatment were significantly lower than animals treated with AP (two-way ANOVA, p = 0.033). Finally, the potential for induced neurogenesis following the combined treatment was investigated using a marker of DNA synthesis. However, no evidence of neurogenesis was observed in the SGN population. The results indicate that chronic NT delivery to the cochlea may be beneficial to cochlear implant patients by increasing the number of viable SGNs and decreasing activation thresholds compared to chronic ES alone. PMID:21762764

  18. Spiral ganglion neuron survival and function in the deafened cochlea following chronic neurotrophic treatment.

    PubMed

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

    2011-12-01

    Cochlear implants electrically stimulate residual spiral ganglion neurons (SGNs) to provide auditory cues for the severe-profoundly deaf. However, SGNs gradually degenerate following cochlear hair cell loss, leaving fewer neurons available for stimulation. Providing an exogenous supply of neurotrophins (NTs) has been shown to prevent SGN degeneration, and when combined with chronic intracochlear electrical stimulation (ES) following a short period of deafness (5 days), may also promote the formation of new neurons. The present study assessed the histopathological response of guinea pig cochleae treated with NTs (brain-derived neurotrophic factor and neurotrophin-3) with and without ES over a four week period, initiated two weeks after deafening. Results were compared to both NT alone and artificial perilymph (AP) treated animals. AP/ES treated animals exhibited no evidence of SGN rescue compared with untreated deafened controls. In contrast, NT administration showed a significant SGN rescue effect in the lower and middle cochlear turns (two-way ANOVA, p < 0.05) compared with AP-treated control animals. ES in combination with NT did not enhance SGN survival compared with NT alone. SGN function was assessed by measuring electrically-evoked auditory brainstem response (EABR) thresholds. EABR thresholds following NT treatment were significantly lower than animals treated with AP (two-way ANOVA, p = 0.033). Finally, the potential for induced neurogenesis following the combined treatment was investigated using a marker of DNA synthesis. However, no evidence of neurogenesis was observed in the SGN population. The results indicate that chronic NT delivery to the cochlea may be beneficial to cochlear implant patients by increasing the number of viable SGNs and decreasing activation thresholds compared to chronic ES alone. PMID:21762764

  19. Intraosseous ganglion cyst of the lunate: A case report.

    PubMed

    Sbai, Mohamed-Ali; Benzarti, Sofien; Boussen, Monia; Msek, Hichem; Maalla, Riadh

    2016-06-01

    Intraosseous ganglion cyst of the carpal bones represents a rare cause of wrist pain. We report a case of a 42 year-old, right-handed female, who presented with pain of the right wrist following a fall on the palm of the hand. Clinical study revealed a moderate swelling over the mid-section of the palmar face and pain through extreme ranges of motion of the wrist. Plain radiographs and CT-scan of the wrist have revealed an intraosseous ganglion cyst of the lunate bone. Curetting-filling by Kuhlman's vascularized radial bone graft allowed a good functional recovery. The clinical, radiological and therapeutic aspects are discussed. PMID:27321303

  20. Myelin-specific Th17 cells induce severe relapsing optic neuritis with irreversible loss of retinal ganglion cells in C57BL/6 mice

    PubMed Central

    Larabee, Chelsea M.; Hu, Yang; Desai, Shruti; Georgescu, Constantin; Wren, Jonathan D.; Axtell, Robert C.

    2016-01-01

    Purpose Optic neuritis affects most patients with multiple sclerosis (MS), and current treatments are unreliable. The purpose of this study was to characterize the contribution of Th1 and Th17 cells to the development of optic neuritis. Methods Mice were passively transferred myelin-specific Th1 or Th17 cells to induce experimental autoimmune encephalomyelitis (EAE), a model of neuroautoimmunity. Visual acuity was assessed daily with optokinetic tracking, and 1, 2, and 3 weeks post-induction, optic nerves and retinas were harvested for immunohistochemical analyses. Results Passive transfer experimental autoimmune encephalomyelitis elicits acute episodes of asymmetric visual deficits and is exacerbated in Th17-EAE relative to Th1-EAE. The Th17-EAE optic nerves contained more inflammatory infiltrates and an increased neutrophil to macrophage ratio. Significant geographic degeneration of the retinal ganglion cells accompanied Th17-EAE but not Th1. Conclusions Th17-induced transfer EAE recapitulates pathologies observed in MS-associated optic neuritis, namely, monocular episodes of vision loss, optic nerve inflammation, and geographic retinal ganglion cell (RGC) degeneration. PMID:27122964

  1. AAV-mediated Gene Therapy Halts Retinal Degeneration in PDE6β-deficient Dogs.

    PubMed

    Pichard, Virginie; Provost, Nathalie; Mendes-Madeira, Alexandra; Libeau, Lyse; Hulin, Philippe; Tshilenge, Kizito-Tshitoko; Biget, Marine; Ameline, Baptiste; Deschamps, Jack-Yves; Weber, Michel; Le Meur, Guylène; Colle, Marie-Anne; Moullier, Philippe; Rolling, Fabienne

    2016-05-01

    We previously reported that subretinal injection of AAV2/5 RK.cpde6β allowed long-term preservation of photoreceptor function and vision in the rod-cone dysplasia type 1 (rcd1) dog, a large animal model of naturally occurring PDE6β deficiency. The present study builds on these earlier findings to provide a detailed assessment of the long-term effects of gene therapy on the spatiotemporal pattern of retinal degeneration in rcd1 dogs treated at 20 days of age. We analyzed the density distribution of the retinal layers and of particular photoreceptor cells in 3.5-year-old treated and untreated rcd1 dogs. Whereas no rods were observed outside the bleb or in untreated eyes, gene transfer halted rod degeneration in all vector-exposed regions. Moreover, while gene therapy resulted in the preservation of cones, glial cells and both the inner nuclear and ganglion cell layers, no cells remained in vector-unexposed retinas, except in the visual streak. Finally, the retinal structure of treated 3.5-year-old rcd1 dogs was identical to that of unaffected 4-month-old rcd1 dogs, indicating near complete preservation. Our findings indicate that gene therapy arrests the degenerative process even if intervention is initiated after the onset of photoreceptor degeneration, and point to significant potential of this therapeutic approach in future clinical trials. PMID:26857842

  2. Role of Cytokines in Intervertebral Disc Degeneration: Pain and Disc-content

    PubMed Central

    Risbud, Makarand V.; Shapiro, Irving. M

    2014-01-01

    Degeneration of the intervertebral disc is the major contributor to back/neck and radicular pain. It is characterized by an elevation in levels of the inflammatory cytokines tumor necrosis factor (TNF)-α, interleukin (IL)-1 α/β, IL-6 and IL-17 secreted by the disc cells themselves; these cytokines promote matrix degradation, chemokine production and changes in cell phenotype. The resulting imbalance between catabolic and anabolic responses leads to degeneration, as well as herniation and radicular pain. Release of chemokines from degenerating discs promote infiltration and activation of T and B cells, macrophages, neutrophils, and mast cells further amplifying the inflammatory cascade. Immunocyte migration into the disc is accompanied by the appearance of microvasculature and nerve fibers arising from the dorsal root ganglion (DRG). In this inflammatory milieu, neurogenic factors in particular nerve growth factor (NGF) and brain-derive neurotrophic factor (BDNF) generated by disc and immune cells induce expression of pain associated cation channels in DRGs. Depolarization of these channels is likely to promote discogenic and radicular pain and reinforce the cytokine-mediated degenerative cascade. Taken together, the enhanced understanding of the contribution of cytokines and immune cells to catabolic and nociceptive processes provide new targets for treating symptomatic disc disease. PMID:24166242

  3. Vaccination for protection of retinal ganglion cells against death from glutamate cytotoxicity and ocular hypertension: Implications for glaucoma

    NASA Astrophysics Data System (ADS)

    Schori, Hadas; Kipnis, Jonathan; Yoles, Eti; Woldemussie, Elizabeth; Ruiz, Guadalupe; Wheeler, Larry A.; Schwartz, Michal

    2001-03-01

    Our group recently demonstrated that autoimmune T cells directed against central nervous system-associated myelin antigens protect neurons from secondary degeneration. We further showed that the synthetic peptide copolymer 1 (Cop-1), known to suppress experimental autoimmune encephalomyelitis, can be safely substituted for the natural myelin antigen in both passive and active immunization for neuroprotection of the injured optic nerve. Here we attempted to determine whether similar immunizations are protective from retinal ganglion cell loss resulting from a direct biochemical insult caused, for example, by glutamate (a major mediator of degeneration in acute and chronic optic nerve insults) and in a rat model of ocular hypertension. Passive immunization with T cells reactive to myelin basic protein or active immunization with myelin oligodendrocyte glycoprotein-derived peptide, although neuroprotective after optic nerve injury, was ineffective against glutamate toxicity in mice and rats. In contrast, the number of surviving retinal ganglion cells per square millimeter in glutamate-injected retinas was significantly larger in mice immunized 10 days previously with Cop-1 emulsified in complete Freund's adjuvant than in mice injected with PBS in the same adjuvant (2,133 ± 270 and 1,329 ± 121, respectively, mean ± SEM; P < 0.02). A similar pattern was observed when mice were immunized on the day of glutamate injection (1,777 ± 101 compared with 1,414 ± 36; P <0.05), but not when they were immunized 48h later. These findings suggest that protection from glutamate toxicity requires reinforcement of the immune system by antigens that are different from those associated with myelin. The use of Cop-1 apparently circumvents this antigen specificity barrier. In the rat ocular hypertension model, which simulates glaucoma, immunization with Cop-1 significantly reduced the retinal ganglion cell loss from 27.8%±6.8% to 4.3%±1.6%, without affecting the intraocular pressure

  4. Novel High Content Screen Detects Compounds That Promote Neurite Regeneration from Cochlear Spiral Ganglion Neurons.

    PubMed

    Whitlon, Donna S; Grover, Mary; Dunne, Sara F; Richter, Sonja; Luan, Chi-Hao; Richter, Claus-Peter

    2015-01-01

    The bipolar spiral ganglion neurons (SGN) carry sound information from cochlear hair cells to the brain. After noise, antibiotic or toxic insult to the cochlea, damage to SGN and/or hair cells causes hearing impairment. Damage ranges from fiber and synapse degeneration to dysfunction and loss of cells. New interventions to regenerate peripheral nerve fibers could help reestablish transfer of auditory information from surviving or regenerated hair cells or improve results from cochlear implants, but the biochemical mechanisms to target are largely unknown. Presently, no drugs exist that are FDA approved to stimulate the regeneration of SGN nerve fibers. We designed an original phenotypic assay to screen 440 compounds of the NIH Clinical Collection directly on dissociated mouse spiral ganglia. The assay detected one compound, cerivastatin, that increased the length of regenerating neurites. The effect, mimicked by other statins at different optimal concentrations, was blocked by geranylgeraniol. These results demonstrate the utility of screening small compound libraries on mixed cultures of dissociated primary ganglia. The success of this screen narrows down a moderately sized library to a single compound which can be elevated to in-depth in vivo studies, and highlights a potential new molecular pathway for targeting of hearing loss drugs. PMID:26521685

  5. Novel High Content Screen Detects Compounds That Promote Neurite Regeneration from Cochlear Spiral Ganglion Neurons

    PubMed Central

    Whitlon, Donna S.; Grover, Mary; Dunne, Sara F.; Richter, Sonja; Luan, Chi-Hao; Richter, Claus-Peter

    2015-01-01

    The bipolar spiral ganglion neurons (SGN) carry sound information from cochlear hair cells to the brain. After noise, antibiotic or toxic insult to the cochlea, damage to SGN and/or hair cells causes hearing impairment. Damage ranges from fiber and synapse degeneration to dysfunction and loss of cells. New interventions to regenerate peripheral nerve fibers could help reestablish transfer of auditory information from surviving or regenerated hair cells or improve results from cochlear implants, but the biochemical mechanisms to target are largely unknown. Presently, no drugs exist that are FDA approved to stimulate the regeneration of SGN nerve fibers. We designed an original phenotypic assay to screen 440 compounds of the NIH Clinical Collection directly on dissociated mouse spiral ganglia. The assay detected one compound, cerivastatin, that increased the length of regenerating neurites. The effect, mimicked by other statins at different optimal concentrations, was blocked by geranylgeraniol. These results demonstrate the utility of screening small compound libraries on mixed cultures of dissociated primary ganglia. The success of this screen narrows down a moderately sized library to a single compound which can be elevated to in-depth in vivo studies, and highlights a potential new molecular pathway for targeting of hearing loss drugs. PMID:26521685

  6. Partial requirement of endothelin receptor B in spiral ganglion neurons for postnatal development of hearing.

    PubMed

    Ida-Eto, Michiru; Ohgami, Nobutaka; Iida, Machiko; Yajima, Ichiro; Kumasaka, Mayuko Y; Takaiwa, Kazutaka; Kimitsuki, Takashi; Sone, Michihiko; Nakashima, Tsutomu; Tsuzuki, Toyonori; Komune, Shizuo; Yanagisawa, Masashi; Kato, Masashi

    2011-08-26

    Impairments of endothelin receptor B (Ednrb/EDNRB) cause the development of Waardenburg-Shah syndrome with congenital hearing loss, hypopigmentation, and megacolon disease in mice and humans. Hearing loss in Waardenburg-Shah syndrome has been thought to be caused by an Ednrb-mediated congenital defect of melanocytes in the stria vascularis (SV) of inner ears. Here we show that Ednrb expressed in spiral ganglion neurons (SGNs) in inner ears is required for postnatal development of hearing in mice. Ednrb protein was expressed in SGNs from WT mice on postnatal day 19 (P19), whereas it was undetectable in SGNs from WT mice on P3. Correspondingly, Ednrb homozygously deleted mice (Ednrb(-/-) mice) with congenital hearing loss showed degeneration of SGNs on P19 but not on P3. The congenital hearing loss involving neurodegeneration of SGNs as well as megacolon disease in Ednrb(-/-) mice were markedly improved by introducing an Ednrb transgene under control of the dopamine β-hydroxylase promoter (Ednrb(-/-);DBH-Ednrb mice) on P19. Neither defects of melanocytes nor hypopigmentation in the SV and skin in Ednrb(-/-) mice was rescued in the Ednrb(-/-);DBH-Ednrb mice. Thus, the results of this study indicate a novel role of Ednrb expressed in SGNs distinct from that in melanocytes in the SV contributing partially to postnatal hearing development. PMID:21715336

  7. Schwann cells genetically modified to express neurotrophins promote spiral ganglion neuron survival in vitro

    PubMed Central

    Pettingill, Lisa N.; Minter, Ricki L.; Shepherd, Robert K.

    2009-01-01

    The intracochlear infusion of neurotrophic factors via a mini-osmotic pump has been shown to prevent deafness-induced spiral ganglion neuron (SGN) degeneration; however, the use of pumps may increase the incidence of infection within the cochlea, making this technique unsuitable for neurotrophin administration in a clinical setting. Cell- and gene-based therapies are potential therapeutic options. This study investigated whether Schwann cells which were genetically modified to over-express the neurotrophins brain-derived neurotrophic factor (BDNF) or neurotrophin 3 (Ntf3, formerly NT-3) could support SGN survival in an in vitro model of deafness. Co-culture of either BDNF over-expressing Schwann cells or Ntf3 over-expressing Schwann cells with SGNs from early postnatal rats significantly enhanced neuronal survival in comparison to both control Schwann cells and conventional recombinant neurotrophin proteins. Transplantation of neurotrophin over-expressing Schwann cells into the cochlea may provide an alternative means of delivering neurotrophic factors to the deaf cochlea for therapeutic purposes. PMID:18304740

  8. Diffuse Traumatic Axonal Injury in the Optic Nerve Does Not Elicit Retinal Ganglion Cell Loss

    PubMed Central

    Wang, Jiaqiong; Fox, Michael A.; Povlishock, John T.

    2013-01-01

    Much of the morbidity following traumatic brain injury (TBI) is associated with traumatic axonal injury (TAI). Although most TAI studies focus on corpus callosum white matter, the visual system has received increased interest. To assess visual system TAI, we developed a mouse model of optic nerve TAI. It is unknown, however, whether this TAI causes retinal ganglion cell (RGC) death. To address this issue, YFP-16 transgenic mice were subjected to mild TBI and followed from 2 to 28 days. Neither TUNEL-positive or cleaved caspase-3 immunoreactive RGCs were observed from 2 to 28 days post-TBI. Quantification of immunoreactivity of Brn3a, an RGC marker, demonstrated no RGC loss; parallel electron microscopic analysis confirmed RGC viability. Persistent RGC survival was also consistent with the finding of reorganization in the proximal axonal segments following TAI wherein microglia/macrophages remained inactive. In contrast, activated microglia/macrophages closely enveloped the distal disconnected, degenerating axonal segments at 7 to 28 days post-injury, thereby confirming that this model consistently evoked TAI followed by disconnection. Collectively, these data provide novel insight into the evolving pathobiology associated with TAI that will form a foundation for future studies exploring TAI therapy and its downstream consequences. PMID:23860030

  9. Degeneration of a Nonrecombining Chromosome

    NASA Astrophysics Data System (ADS)

    Rice, William R.

    1994-01-01

    Comparative studies suggest that sex chromosomes begin as ordinary autosomes that happen to carry a major sex determining locus. Over evolutionary time the Y chromosome is selected to stop recombining with the X chromosome, perhaps in response to accumulation of alleles beneficial to the heterogametic but harmful to the homogametic sex. Population genetic theory predicts that a nonrecombining Y chromosome should degenerate. Here this prediction is tested by application of specific selection pressures to Drosophila melanogaster populations. Results demonstrate the decay of a nonrecombining, nascent Y chromosome and the capacity for recombination to ameliorate such decay.

  10. [Age-related macular degeneration].

    PubMed

    Budzinskaia, M V

    2014-01-01

    The review provides an update on the pathogenesis and new treatment modalities for neovascular age-related macular degeneration (AMD). The impact of polymorphism in particular genes, including complement factor H (CFH), age-related maculopathy susceptibility 2 (ARMS2/LOC387715), and serine peptidase (HTRA1), on AMD development is discussed. Clinical presentations of different forms of exudative AMD, that is classic, occult, or more often mixed choroidal neovascularization, retinal angiomatous proliferation, and choroidal polypoidal vasculopathy, are described. Particular attention is paid to the results of recent clinical trials and safety issues around the therapy. PMID:25715554

  11. Ultraviolet spectrophotometry of degenerate stars

    NASA Technical Reports Server (NTRS)

    Greenstein, J. L.; Oke, J. B.

    1979-01-01

    Observations of one helium- and three hydrogen-atmosphere degenerates made with the International Ultraviolet Explorer are discussed. Fluxes in the UV give temperatures in good accordance with those determined from the ground and from the ANS satellite data. Profiles of the strong L-alpha absorption in two DA's fit predictions for the expected temperatures. Gravity determination is vitiated by their steep temperature dependence. If one accepts that theoretical predictions should be correct, corrections to the absolute IUE calibration derived are an upward shift of 3-5%, with irregular residuals attaining + or - 7%.

  12. Mathematical glimpse on the Y chromosome degeneration

    NASA Astrophysics Data System (ADS)

    Lobo, M. P.

    2006-04-01

    The Y chromosomes are genetically degenerate and do not recombine with their matching partners X. Non-recombination of XY pairs has been pointed out as the key factor for the degeneration of the Y chromosome. The aim here is to show that there is a mathematical asymmetry in sex chromosomes which leads to the degeneration of Y chromosomes even in the absence of XX and XY recombination. A model for sex-chromosome evolution in a stationary regime is proposed. The consequences of their asymmetry are analyzed and lead us to a couple of conclusions. First, Y chromosome degeneration shows up sqrt{2} more often than X chromosome degeneration. Second, if nature prohibits female mortalities from beeing exactly 50%, then Y chromosome degeneration is inevitable.

  13. New mouse primary retinal degeneration (rd-3)

    SciTech Connect

    Chang, B.; Hawes, N.L.; Roderick, T.H. ); Heckenlively, J.R. )

    1993-04-01

    A new mouse retinal degeneration that appears to be an excellent candidate for modeling human retinitis pigmentosa is reported. In this degeneration, called rd-3, differentiation proceeds postnatally through 2 weeks, and photoreceptor degeneration starts by 3 weeks. The rod photoreceptor loss is essentially complete by 5 weeks, whereas remnant cone cells are seen through 7 weeks. This is the only mouse homozygous retinal degeneration reported to date in which photoreceptors are initially normal. Crosses with known mouse retinal degenerations rd, Rds, nr, and pcd are negative for retinal degeneration in offspring, and linkage analysis places rd-3 on mouse chromosome 1 at 10 [+-]2.5 cM distal to Akp-1. Homology mapping suggests that the homologous human locus should be on chromosome 1q. 32 refs., 3 figs., 3 tabs.

  14. Axon degeneration: context defines distinct pathways.

    PubMed

    Geden, Matthew J; Deshmukh, Mohanish

    2016-08-01

    Axon degeneration is an essential part of development, plasticity, and injury response and has been primarily studied in mammalian models in three contexts: 1) Axotomy-induced Wallerian degeneration, 2) Apoptosis-induced axon degeneration (axon apoptosis), and 3) Axon pruning. These three contexts dictate engagement of distinct pathways for axon degeneration. Recent advances have identified the importance of SARM1, NMNATs, NAD+ depletion, and MAPK signaling in axotomy-induced Wallerian degeneration. Interestingly, apoptosis-induced axon degeneration and axon pruning have many shared mechanisms both in signaling (e.g. DLK, JNKs, GSK3α/β) and execution (e.g. Puma, Bax, caspase-9, caspase-3). However, the specific mechanisms by which caspases are activated during apoptosis versus pruning appear distinct, with apoptosis requiring Apaf-1 but not caspase-6 while pruning requires caspase-6 but not Apaf-1. PMID:27197022

  15. Ganglion Cell Regeneration Following Whole-Retina Destruction in Zebrafish

    PubMed Central

    Sherpa, Tshering; Fimbel, Shane M.; Mallory, Dianne E.; Maaswinkel, Hans; Spritzer, Scott D.; Sand, Jordan A.; Li, L.; Hyde, David R.; Stenkamp, Deborah L.

    2008-01-01

    The retinas of adult teleost fish can regenerate neurons following injury. The current study provides the first documentation of functional whole retina regeneration in the zebrafish, Danio rerio, following intraocular injection of the cytotoxin, ouabain. Loss and replacement of laminated retinal tissue was monitored by analysis of cell death and cell proliferation, and by analysis of retina-specific gene expression patterns. The spatiotemporal process of retinal ganglion cell (RGC) regeneration was followed through the use of selective markers, and was found to largely recapitulate the spatiotemporal process of embryonic ganglion cell neurogenesis, over a more protracted time frame. However, the re-expression of some ganglion cell markers was not observed. The growth and pathfinding of ganglion cell axons was evaluated by measurement of the optic nerve head (ONH), and the restoration of normal ONH size was found to correspond to the time of recovery of two visually-mediated behaviors. However, some abnormalities were noted, including overproduction of RGCs, and progressive and excessive growth of the ONH at longer recovery times. This model system for whole-retina regeneration has provided an informative view of the regenerative process. PMID:18000816

  16. Dorsal raphe nucleus projecting retinal ganglion cells: Why Y cells?

    PubMed Central

    Pickard, Gary E.; So, Kwok-Fai; Pu, Mingliang

    2015-01-01

    Retinal ganglion Y (alpha) cells are found in retinas ranging from frogs to mice to primates. The highly conserved nature of the large, fast conducting retinal Y cell is a testament to its fundamental task, although precisely what this task is remained ill-defined. The recent discovery that Y-alpha retinal ganglion cells send axon collaterals to the serotonergic dorsal raphe nucleus (DRN) in addition to the lateral geniculate nucleus (LGN), medial interlaminar nucleus (MIN), pretectum and the superior colliculus (SC) has offered new insights into the important survival tasks performed by these cells with highly branched axons. We propose that in addition to its role in visual perception, the Y-alpha retinal ganglion cell provides concurrent signals via axon collaterals to the DRN, the major source of serotonergic afferents to the forebrain, to dramatically inhibit 5-HT activity during orientation or alerting/escape responses, which dis-facilitates ongoing tonic motor activity while dis-inhibiting sensory information processing throughout the visual system. The new data provide a fresh view of these evolutionarily old retinal ganglion cells. PMID:26363667

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

    PubMed

    Freeman, Daniel K; Rizzo, Joseph F; 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. PMID:21593546

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

    NASA Astrophysics Data System (ADS)

    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.

  19. Molecular Responses of the Spiral Ganglion to Aminoglycosides

    ERIC Educational Resources Information Center

    Balaban, Carey D.

    2005-01-01

    Aminoglycosides are toxic to both the inner ear hair cells and the ganglion cells that give rise to the eighth cranial nerve. According to recent studies, these cells have a repertoire of molecular responses to aminoglycoside exposure that engages multiple neuroprotective mechanisms. The responses appear to involve regulation of ionic homeostasis,…

  20. Arthroscopic Treatment of Intraosseous Ganglion Cyst of the Lunate Bone

    PubMed Central

    Cerlier, Alexandre; Gay, André-Mathieu; Levadoux, Michel

    2015-01-01

    Intraosseous ganglion cysts are rare causes of wrist pain. Surgical treatment of this pathologic condition yields good results and a low recurrence rate. The main complications are joint stiffness and vascular disturbances of the lunate bone. Wrist arthroscopy is a surgical technique that reduces the intra-articular operative area and therefore minimizes postoperative stiffness. This article describes an arthroscopic technique used for lunate intraosseous cyst resection associated with an autologous bone graft in a series of cases to prevent joint stiffness while respecting the scapholunate ligament. This study was based on a series of 4 patients, all of whom had wrist pain because of intraosseous ganglion cysts. Arthrosynovial cyst resection, ganglion curettage, and bone grafting were performed arthroscopically. Pain had totally disappeared within 2 months after the operation in 100% of patients. The average hand grip strength was estimated at 100% compared with the opposite side, and articular ranges of motion were the same on both sides in 100% of cases. No complications were reported after surgery. On the basis of these results, arthroscopic treatment of intraosseous synovial ganglion cysts seems to be more efficient and helpful in overcoming the limitations of classic open surgery in terms of complications. PMID:26697314

  1. Dorsal raphe nucleus projecting retinal ganglion cells: Why Y cells?

    PubMed

    Pickard, Gary E; So, Kwok-Fai; Pu, Mingliang

    2015-10-01

    Retinal ganglion Y (alpha) cells are found in retinas ranging from frogs to mice to primates. The highly conserved nature of the large, fast conducting retinal Y cell is a testament to its fundamental task, although precisely what this task is remained ill-defined. The recent discovery that Y-alpha retinal ganglion cells send axon collaterals to the serotonergic dorsal raphe nucleus (DRN) in addition to the lateral geniculate nucleus (LGN), medial interlaminar nucleus (MIN), pretectum and the superior colliculus (SC) has offered new insights into the important survival tasks performed by these cells with highly branched axons. We propose that in addition to its role in visual perception, the Y-alpha retinal ganglion cell provides concurrent signals via axon collaterals to the DRN, the major source of serotonergic afferents to the forebrain, to dramatically inhibit 5-HT activity during orientation or alerting/escape responses, which dis-facilitates ongoing tonic motor activity while dis-inhibiting sensory information processing throughout the visual system. The new data provide a fresh view of these evolutionarily old retinal ganglion cells. PMID:26363667

  2. Basal ganglion stroke presenting as subtle behavioural change.

    PubMed

    Wagner, Stephanie J; Begaz, T

    2009-01-01

    Cerebral infarctions can have many presentations ranging from hemiparesis to subtle behavioural changes. A case is presented in which the only sign of a left basal ganglion infarct was isolated abulia. This case highlights the importance of a thorough evaluation in cases of acute unexplained changes in behaviour. PMID:21686449

  3. Basal ganglion stroke presenting as subtle behavioural change.

    PubMed

    Wagner, S J; Begaz, T

    2008-07-01

    Cerebral infarctions can have many presentations ranging from hemiparesis to subtle behavioural changes. A case is presented in which the only sign of a left basal ganglion infarct was isolated abulia. This case highlights the importance of a thorough evaluation in cases of acute unexplained changes in behaviour. PMID:18573972

  4. Arthroscopic Treatment of Intraosseous Ganglion Cyst of the Lunate Bone.

    PubMed

    Cerlier, Alexandre; Gay, André-Mathieu; Levadoux, Michel

    2015-10-01

    Intraosseous ganglion cysts are rare causes of wrist pain. Surgical treatment of this pathologic condition yields good results and a low recurrence rate. The main complications are joint stiffness and vascular disturbances of the lunate bone. Wrist arthroscopy is a surgical technique that reduces the intra-articular operative area and therefore minimizes postoperative stiffness. This article describes an arthroscopic technique used for lunate intraosseous cyst resection associated with an autologous bone graft in a series of cases to prevent joint stiffness while respecting the scapholunate ligament. This study was based on a series of 4 patients, all of whom had wrist pain because of intraosseous ganglion cysts. Arthrosynovial cyst resection, ganglion curettage, and bone grafting were performed arthroscopically. Pain had totally disappeared within 2 months after the operation in 100% of patients. The average hand grip strength was estimated at 100% compared with the opposite side, and articular ranges of motion were the same on both sides in 100% of cases. No complications were reported after surgery. On the basis of these results, arthroscopic treatment of intraosseous synovial ganglion cysts seems to be more efficient and helpful in overcoming the limitations of classic open surgery in terms of complications. PMID:26697314

  5. A new sclerotherapy technique for the wrist ganglion: transcutaneous electrocauterization.

    PubMed

    Gümüş, Nazim

    2009-07-01

    Ganglion, a cystic benign mass, most common soft tissue tumor of the hand, usually occurs in hand, wrist, and foot. In this study, we discuss a new sclerotherapy technique through which 17 patients with wrist ganglion were treated by using short bursts of high-frequency low voltage electrodessication delivered through a fine electrode that was inserted into the sac. Their ages varied from 28 to 52 with an average of 32.7 years. Two patients had volar wrist and 15 others had dorsal ganglia. In all patients, an ultrasound imaging was done for the discrimination of the other hand tumors. Under aseptic conditions, first ganglion was aspirated by using a large needle, which was commonly used for peripheric venous catheterization, and 0.5 mL of 1% xylocaine was injected into the cystic cavity, then electrocauterization was done. In the postoperative follow-up ranging from 6 to 29 months, 1 recurrence developed 3 months after the intervention, requiring the same procedure to overcome it. No complication occurred and all complaints of the patients resolved with this approach. The present technique is simple, safe, effective, and inexpensive for ganglion sclerotherapy, resulting in hopeful outcomes to become as an acceptable alternative to the open surgery. PMID:19546671

  6. [Age-related macular degeneration].

    PubMed

    Garcia Layana, A

    1998-01-01

    Age-related macular degeneration (ARMD) is the leading cause of blindness in the occidental world. Patients suffering this process have an important reduction on their quality of life being handicapped to read, to write, to recognise faces of their friends, or even to watch the television. One of the main problems of that disease is the absence of an effective treatment able to revert the process. Laser treatment is only useful in a limited number of patients, and even in these cases recurrent lesions are frequent. These facts and the progressive ageing of our society establish the ARMD as one of the biggest aim of medical investigations for the next century, and currently is focus of attention in the most industrialised countries. One of the most promising pieces of research is focused in the investigation of the risk factors associated with the age-related macular degeneration, in order to achieve a prophylactic treatment avoiding its appearance. Diet elements such as fat ingestion or reduced antioxidant intakes are being investigated as some of these factors, what open a new possibility for a prophylactic treatment. Finally, research is looking for new therapeutic modalities such as selective radiotherapy in order to improve or maintain the vision of these patients. PMID:10420956

  7. Differential cellular localization of antioxidant enzymes in the trigeminal ganglion.

    PubMed

    Sato, H; Shibata, M; Shimizu, T; Shibata, S; Toriumi, H; Ebine, T; Kuroi, T; Iwashita, T; Funakubo, M; Kayama, Y; Akazawa, C; Wajima, K; Nakagawa, T; Okano, H; Suzuki, N

    2013-09-17

    Because of its high oxygen demands, neural tissue is predisposed to oxidative stress. Here, our aim was to clarify the cellular localization of antioxidant enzymes in the trigeminal ganglion. We found that the transcriptional factor Sox10 is localized exclusively in satellite glial cells (SGCs) in the adult trigeminal ganglion. The use of transgenic mice that express the fluorescent protein Venus under the Sox10 promoter enabled us to distinguish between neurons and SGCs. Although both superoxide dismutases 1 and 2 were present in the neurons, only superoxide dismutase 1 was identified in SGCs. The enzymes relevant to hydrogen peroxide degradation displayed differential cellular localization, such that neurons were endowed with glutathione peroxidase 1 and thioredoxin 2, and catalase and thioredoxin 2 were present in SGCs. Our immunohistochemical finding showed that only SGCs were labeled by the oxidative damage marker 8-hydroxy-2'-deoxyguanosine, which indicates that the antioxidant systems of SGCs were less potent. The transient receptor potential vanilloid subfamily member 1 (TRPV1), the capsaicin receptor, is implicated in inflammatory hyperalgesia, and we demonstrated that topical capsaicin application causes short-lasting mechanical hyperalgesia in the face. Our cell-based assay revealed that TRPV1 agonist stimulation in the presence of TRPV1 overexpression caused reactive oxygen species-mediated caspase-3 activation. Moreover, capsaicin induced the cellular demise of primary TRPV1-positive trigeminal ganglion neurons in a dose-dependent manner, and this effect was inhibited by a free radical scavenger and a pancaspase inhibitor. This study delineates the localization of antioxidative stress-related enzymes in the trigeminal ganglion and reveals the importance of the pivotal role of reactive oxygen species in the TRPV1-mediated caspase-dependent cell death of trigeminal ganglion neurons. Therapeutic measures for antioxidative stress should be taken to prevent

  8. Retinal Ganglion Cell Adaptation to Small Luminance Fluctuations

    PubMed Central

    Freeman, Daniel K.; Graña, Gilberto

    2010-01-01

    To accommodate the wide input range over which the visual system operates within the narrow output range of spiking neurons, the retina adjusts its sensitivity to the mean light level so that retinal ganglion cells can faithfully signal contrast, or relative deviations from the mean luminance. Given the large operating range of the visual system, the majority of work on luminance adaptation has involved logarithmic changes in light level. We report that luminance gain controls are recruited for remarkably small fluctuations in luminance as well. Using spike recordings from the rat optic tract, we show that ganglion cell responses to a brief flash of light are modulated in amplitude by local background fluctuations as little as 15% contrast. The time scale of the gain control is rapid (<125 ms), at least for on cells. The retinal locus of adaptation precedes the ganglion cell spike generator because response gain changes of on cells were uncorrelated with firing rate. The mechanism seems to reside within the inner retinal network and not in the photoreceptors, because the adaptation profiles of on and off cells differed markedly. The response gain changes follow Weber's law, suggesting that network mechanisms of luminance adaptation described in previous work modulates retinal ganglion cell sensitivity, not just when we move between different lighting environments, but also as our eyes scan a visual scene. Finally, we show that response amplitude is uniformly reduced for flashes on a modulated background that has spatial contrast, indicating that another gain control that integrates luminance signals nonlinearly over space operates within the receptive field center of rat ganglion cells. PMID:20538771

  9. Flexor Tendon Sheath Ganglions: Results of Surgical Excision

    PubMed Central

    Spencer, Edwin E.

    2007-01-01

    The purpose of our study was to review the clinical features and determine the results following surgical excision of a flexor tendon sheath ganglion. A retrospective analysis of 24 consecutive patients (25 ganglions) who underwent excision of a painful flexor tendon sheath ganglion by the same surgeon was performed. The patient’s medical and operative records were reviewed. Each patient was invited to return for an evaluation, which consisted of a clinical interview, completion of a questionnaire, and physical examination. Those patients that were unable to return underwent a detailed telephone interview. Sixteen patients returned for a clinical evaluation, while eight patients underwent a telephone interview. There were 15 women and nine men, with an average age of 43 years (range, 21–68 years). The dominant hand was involved in 15 patients. The long finger was most commonly involved (11 cases). The ganglion arose from the A1 pulley in 13 cases, between the A1 and A2 pulleys in three cases, and from the A2 pulley in nine cases. At an average follow-up of 18.5 months (range, 5–38 months), all of the patients were satisfied with their final result. No patient developed a recurrence and all returned to their previous functional level. There were two minor complications that resolved uneventfully; one patient experienced mild incisional tenderness, while an additional patient experienced transient digital nerve paresthesias. We conclude that surgical excision is a simple, safe, and effective method for treating a painful ganglion of the digital flexor tendon sheath. PMID:18780066

  10. Retinal ganglion cell responses to voltage and current stimulation in wild-type and rd1 mouse retinas

    NASA Astrophysics Data System (ADS)

    Goo, Yong Sook; Ye, Jang Hee; Lee, Seokyoung; Nam, Yoonkey; Ryu, Sang Baek; Kim, Kyung Hwan

    2011-06-01

    Retinal prostheses are being developed to restore vision for those with retinal diseases such as retinitis pigmentosa or age-related macular degeneration. Since neural prostheses depend upon electrical stimulation to control neural activity, optimal stimulation parameters for successful encoding of visual information are one of the most important requirements to enable visual perception. In this paper, we focused on retinal ganglion cell (RGC) responses to different stimulation parameters and compared threshold charge densities in wild-type and rd1 mice. For this purpose, we used in vitro retinal preparations of wild-type and rd1 mice. When the neural network was stimulated with voltage- and current-controlled pulses, RGCs from both wild-type and rd1 mice responded; however the temporal pattern of RGC response is very different. In wild-type RGCs, a single peak within 100 ms appears, while multiple peaks (approximately four peaks) with ~10 Hz rhythm within 400 ms appear in RGCs in the degenerated retina of rd1 mice. We find that an anodic phase-first biphasic voltage-controlled pulse is more efficient for stimulation than a biphasic current-controlled pulse based on lower threshold charge density. The threshold charge densities for activation of RGCs both with voltage- and current-controlled pulses are overall more elevated for the rd1 mouse than the wild-type mouse. Here, we propose the stimulus range for wild-type and rd1 retinas when the optimal modulation of a RGC response is possible.

  11. Loss of function of Ywhah in mice induces deafness and cochlear outer hair cells' degeneration

    PubMed Central

    Buret, L; Rebillard, G; Brun, E; Angebault, C; Pequignot, M; Lenoir, M; Do-cruzeiro, M; Tournier, E; Cornille, K; Saleur, A; Gueguen, N; Reynier, P; Amati-Bonneau, P; Barakat, A; Blanchet, C; Chinnery, P; Yu-Wai-Man, P; Kaplan, J; Roux, A-F; Van Camp, G; Wissinger, B; Boespflug-Tanguy, O; Giraudet, F; Puel, J-L; Lenaers, G; Hamel, C; Delprat, B; Delettre, C

    2016-01-01

    In vertebrates, 14-3-3 proteins form a family of seven highly conserved isoforms with chaperone activity, which bind phosphorylated substrates mostly involved in regulatory and checkpoint pathways. 14-3-3 proteins are the most abundant protein in the brain and are abundantly found in the cerebrospinal fluid in neurodegenerative diseases, suggesting a critical role in neuron physiology and death. Here we show that 14-3-3eta-deficient mice displayed auditory impairment accompanied by cochlear hair cells' degeneration. We show that 14-3-3eta is highly expressed in the outer and inner hair cells, spiral ganglion neurons of cochlea and retinal ganglion cells. Screening of YWHAH, the gene encoding the 14-3-3eta isoform, in non-syndromic and syndromic deafness, revealed seven non-synonymous variants never reported before. Among them, two were predicted to be damaging in families with syndromic deafness. In vitro, variants of YWHAH induce mild mitochondrial fragmentation and severe susceptibility to apoptosis, in agreement with a reduced capacity of mutated 14-3-3eta to bind the pro-apoptotic Bad protein. This study demonstrates that YWHAH variants can have a substantial effect on 14-3-3eta function and that 14-3-3eta could be a critical factor in the survival of outer hair cells. PMID:27275396

  12. Quantitative genetic analysis of retinal degeneration in the blind cavefish Astyanax mexicanus.

    PubMed

    O'Quin, Kelly E; Yoshizawa, Masato; Doshi, Pooja; Jeffery, William R

    2013-01-01

    The retina is the light-sensitive tissue of the eye that facilitates vision. Mutations within genes affecting eye development and retinal function cause a host of degenerative visual diseases, including retinitis pigmentosa and anophthalmia/microphthalmia. The characin fish Astyanax mexicanus includes both eyed (surface fish) and eyeless (cavefish) morphs that initially develop eyes with normal retina; however, early in development, the eyes of cavefish degenerate. Since both surface and cave morphs are members of the same species, they serve as excellent evolutionary mutant models with which to identify genes causing retinal degeneration. In this study, we crossed the eyed and eyeless forms of A. mexicanus and quantified the thickness of individual retinal layers among 115 F(2) hybrid progeny. We used next generation sequencing (RAD-seq) and microsatellite mapping to construct a dense genetic map of the Astyanax genome, scan for quantitative trait loci (QTL) affecting retinal thickness, and identify candidate genes within these QTL regions. The map we constructed for Astyanax includes nearly 700 markers assembled into 25 linkage groups. Based on our scans with this map, we identified four QTL, one each associated with the thickness of the ganglion, inner nuclear, outer plexiform, and outer nuclear layers of the retina. For all but one QTL, cavefish alleles resulted in a clear reduction in the thickness of the affected layer. Comparative mapping of genetic markers within each QTL revealed that each QTL corresponds to an approximately 35 Mb region of the zebrafish genome. Within each region, we identified several candidate genes associated with the function of each affected retinal layer. Our study is the first to examine Astyanax retinal degeneration in the context of QTL mapping. The regions we identify serve as a starting point for future studies on the genetics of retinal degeneration and eye disease using the evolutionary mutant model Astyanax. PMID:23437360

  13. Photoreceptor Cells Influence Retinal Vascular Degeneration in Mouse Models of Retinal Degeneration and Diabetes

    PubMed Central

    Liu, Haitao; Tang, Jie; Du, Yunpeng; Saadane, Aicha; Tonade, Deoye; Samuels, Ivy; Veenstra, Alex; Palczewski, Krzysztof; Kern, Timothy S.

    2016-01-01

    Purpose Loss of photoreceptor cells is associated with retinal vascular degeneration in retinitis pigmentosa, whereas the presence of photoreceptor cells is implicated in vascular degeneration in diabetic retinopathy. To investigate how both the absence and presence of photoreceptors could damage the retinal vasculature, we compared two mouse models of photoreceptor degeneration (opsin−/− and RhoP23H/P23H ) and control C57Bl/5J mice, each with and without diabetes. Methods Retinal thickness, superoxide, expression of inflammatory proteins, ERG and optokinetic responses, leukocyte cytotoxicity, and capillary degeneration were evaluated at 1 to 10 months of age using published methods. Results Retinal photoreceptor cells degenerated completely in the opsin mutants by 2 to 4 months of age, and visual function subsided correspondingly. Retinal capillary degeneration was substantial while photoreceptors were still present, but slowed after the photoreceptors degenerated. Diabetes did not further exacerbate capillary degeneration in these models of photoreceptor degeneration, but did cause capillary degeneration in wild-type animals. Photoreceptor cells, however, did not degenerate in wild-type diabetic mice, presumably because the stress responses in these cells were less than in the opsin mutants. Retinal superoxide and leukocyte damage to retinal endothelium contributed to the degeneration of retinal capillaries in diabetes, and leukocyte-mediated damage was increased in both opsin mutants during photoreceptor cell degeneration. Conclusions Photoreceptor cells affect the integrity of the retinal microvasculature. Deterioration of retinal capillaries in opsin mutants was appreciable while photoreceptor cells were present and stressed, but was less after photoreceptors degenerated. This finding proves relevant to diabetes, where persistent stress in photoreceptors likewise contributes to capillary degeneration. PMID:27548901

  14. Genetics of Frontotemporal Lobar Degeneration

    PubMed Central

    Galimberti, Daniela; Scarpini, Elio

    2012-01-01

    Frontotemporal lobar degeneration (FTLD), the most frequent neurodegenerative disorder with a presenile onset, presents with a spectrum of clinical manifestations, ranging from behavioral and executive impairment to language disorders and motor dysfunction. Familial aggregation is frequently reported, and about 10% of cases have an autosomal dominant transmission. Microtubule associated protein tau (MAPT) gene mutations have been the first ones identified and are associated with early onset behavioral variant frontotemporal dementia phenotype. More recently, progranulin gene (GRN) mutations were recognized in association with familial form of FTLD. In addition, other genes are linked to rare cases of familial FTLD. Lastly, a number of genetic risk factors for sporadic forms have also been identified. In this review, current knowledge about mutations at the basis of familial FTLD will be described, together with genetic risk factors influencing the susceptibility to FTLD. PMID:22536193

  15. Hot subdwarfs with degenerate companions

    NASA Astrophysics Data System (ADS)

    Mereghetti, Sandro

    2010-10-01

    Stellar evolutionary models predict that most of the hot sub-dwarfs in close binary systems have white dwarf companions. In a few cases even more massive compact objects (neutron stars or black holes) are suggested by the optical mass functions. The X-ray emission expected from accretion of the sub-dwarf's wind can reveal the nature of the compact companions and be used to derive other important information on these post-common envelope systems, as recently demonstrated by the discovery of a massive WD in HD 49798. We selected 3 promising targets from a sample of hot subdwarfs suspected to have degenerate companions. This proposal was accepted in AO9 with C priority.

  16. Laser therapy and macular degeneration

    NASA Astrophysics Data System (ADS)

    Menchini, Ugo; Virgili, Gianni; Giansanti, Fabrizio; Giacomelli, Giovanni; Cappelli, Stefania

    2001-10-01

    Among macular diseases, choroidal neovascularization (CNV) is one of the most common causes of visual loss, especially in the form associated with age-related macular degeneration and pathologic myopia. Research on these diseases has recently evaluated new treatment modalities that use laser light differently; among these, photodynamic therapy (PDT) has been introduced in the clinical practice, allowing us to expand the possibility of reducing visual loss in patients affected by CNV. With PDT, a photosensitizer (verteporfin, VisudyneTM) is injected intravenously, and it selectively binds to new vessels; low-power laser light exposure then activates the drug, leading to oxidative damage of the endothelium and new vessels thrombosis. Yet, other therapies, such as transpupillary termotherapy, or the use of photocoagulation to cause feeder-vessel occlusion, could proof effective, but they need further investigation.

  17. Degenerate doping of metallic anodes

    DOEpatents

    Friesen, Cody A; Zeller, Robert A; Johnson, Paul B; Switzer, Elise E

    2015-05-12

    Embodiments of the invention relate to an electrochemical cell comprising: (i) a fuel electrode comprising a metal fuel, (ii) a positive electrode, (iii) an ionically conductive medium, and (iv) a dopant; the electrodes being operable in a discharge mode wherein the metal fuel is oxidized at the fuel electrode and the dopant increases the conductivity of the metal fuel oxidation product. In an embodiment, the oxidation product comprises an oxide of the metal fuel which is doped degenerately. In an embodiment, the positive electrode is an air electrode that absorbs gaseous oxygen, wherein during discharge mode, oxygen is reduced at the air electrode. Embodiments of the invention also relate to methods of producing an electrode comprising a metal and a doped metal oxidation product.

  18. Degenerate adiabatic perturbation theory: Foundations and applications

    NASA Astrophysics Data System (ADS)

    Rigolin, Gustavo; Ortiz, Gerardo

    2014-08-01

    We present details and expand on the framework leading to the recently introduced degenerate adiabatic perturbation theory [Phys. Rev. Lett. 104, 170406 (2010), 10.1103/PhysRevLett.104.170406], and on the formulation of the degenerate adiabatic theorem, along with its necessary and sufficient conditions [given in Phys. Rev. A 85, 062111 (2012), 10.1103/PhysRevA.85.062111]. We start with the adiabatic approximation for degenerate Hamiltonians that paves the way to a clear and rigorous statement of the associated degenerate adiabatic theorem, where the non-Abelian geometric phase (Wilczek-Zee phase) plays a central role to its quantitative formulation. We then describe the degenerate adiabatic perturbation theory, whose zeroth-order term is the degenerate adiabatic approximation, in its full generality. The parameter in the perturbative power-series expansion of the time-dependent wave function is directly associated to the inverse of the time it takes to drive the system from its initial to its final state. With the aid of the degenerate adiabatic perturbation theory we obtain rigorous necessary and sufficient conditions for the validity of the adiabatic theorem of quantum mechanics. Finally, to illustrate the power and wide scope of the methodology, we apply the framework to a degenerate Hamiltonian, whose closed-form time-dependent wave function is derived exactly, and also to other nonexactly solvable Hamiltonians whose solutions are numerically computed.

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

    NASA Technical Reports Server (NTRS)

    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.

  20. The functional diversity of retinal ganglion cells in the mouse.

    PubMed

    Baden, Tom; Berens, Philipp; Franke, Katrin; Román Rosón, Miroslav; Bethge, Matthias; Euler, Thomas

    2016-01-21

    In the vertebrate visual system, all output of the retina is carried by retinal ganglion cells. Each type encodes distinct visual features in parallel for transmission to the brain. How many such 'output channels' exist and what each encodes are areas of intense debate. In the mouse, anatomical estimates range from 15 to 20 channels, and only a handful are functionally understood. By combining two-photon calcium imaging to obtain dense retinal recordings and unsupervised clustering of the resulting sample of more than 11,000 cells, here we show that the mouse retina harbours substantially more than 30 functional output channels. These include all known and several new ganglion cell types, as verified by genetic and anatomical criteria. Therefore, information channels from the mouse eye to the mouse brain are considerably more diverse than shown thus far by anatomical studies, suggesting an encoding strategy resembling that used in state-of-the-art artificial vision systems. PMID:26735013

  1. Pure hemidystonia with basal ganglion abnormalities on positron emission tomography

    SciTech Connect

    Perlmutter, J.S.; Raichle, M.E.

    1984-03-01

    We present a patient with hemidystonia and an abnormality of the contralateral basal ganglion seen only with positron emission tomography. A 50-year-old sinistral man suffered minor trauma to the right side of his head and neck. Within 20 minutes he developed paroxysmal intermittent dystonic posturing of his right face, forearm, hand, and foot, with weaker contractions of the left foot, lasting several seconds and recurring every few minutes. Neurological findings between spells were normal. The following were also normal: electrolyte, calcium, magnesium, and arterial blood gas levels, and findings of drug screen, cerebrospinal fluid examination, electroencephalography with nasopharyngeal leads, computed tomographic scanning (initially and four weeks later), and cerebral angiography. Positron emission tomographic scanning revealed abnormalities in the left basal ganglion region, including decreased oxygen metabolism, decreased oxygen extraction, increased blood volume, and increased blood flow.

  2. A Rare Presentation of Ganglion Cyst of the Elbow

    PubMed Central

    Vaishya, Raju; Kapoor, Chirag; Vijay, Vipul

    2016-01-01

    INTRODUCTION: Ganglion cysts are benign soft tissue swellings commonly found in the wrist. The presence of these cysts in the elbow is uncommon, and few case reports have been reported for this condition at this location. These lesions can compress on the neighbouring structures or cause restriction of the joint movement. The awareness of this entity is a must, to arrive at an early diagnosis. MATERIALS AND METHOD: We report a patient with swelling in the anterolateral aspect of the elbow which had been causing intermittent pain for the last 13 months. The MRI revealed a fluid-filled cystic swelling which was communicating with the radio-capitellar joint. RESULTS: The lesion was excised in toto, using anterolateral approach for the elbow, and sent for histopathological examination which confirmed the diagnosis of a ganglion cyst. CONCLUSION: Thus, due to the infrequent presentation, an awareness of this condition is necessary to prevent a delay in diagnosis and its subsequent management. PMID:27493847

  3. Arthroscopic Resection of Wrist Ganglion Arising from the Lunotriquetral Joint

    PubMed Central

    Mak, Michael C. K.; Ho, Pak-cheong; Tse, W. L.; Wong, Clara W. Y.

    2013-01-01

    The dorsal wrist ganglion is the most common wrist mass, and previous studies have shown that it arises from the scapholunate interval in the vast majority of cases. Treatment has traditionally been open excision, and more recently arthroscopic resection has been established as an effective and less invasive treatment method. However, application of this technique to ganglia in atypical locations has not been reported, where open excision is the usual practice. This report describes two cases of atypical dorsal wrist ganglia that arose from the lunotriquetral (LT) joint, demonstrated by arthroscopic visualization and wrist arthrogram in one of them. Arthroscopic resection was performed, and the application of this technique to a dorsal wrist ganglion with an atypical origin and location is described. PMID:24436842

  4. Case report ganglion cysts of the bilateral cruciate ligaments.

    PubMed

    Noda, M; Kurosaka, M; Maeno, K; Mizuno, K

    1999-01-01

    Ganglion cysts originating from the cruciate ligaments have been reported rarely. A 38-year-old woman developed symptoms of knee pain with 10 degrees loss of knee extension. Preoperative magnetic resonance imaging showed a well-demarcated cystic mass surrounding the posterior cruciate ligament so clearly that further examination was not recommended. Because examination under anesthesia confirmed full extension of the knee, we presumed that pain produced by compression caused the diminished extension, and that mechanical block was not the reason. During arthroscopic examination, a mass was impinged between the anterior cruciate ligament and the intercondylar notch when extension of the knee was attempted. The mass was resected and immediate improvement was noted. The patient had experienced the same episode in the contralateral knee and removal of a ganglion cyst on the cruciate ligament 10 years ago. At the latest follow-up she was completely symptom free in both knees without any sign of recurrence. PMID:10564867

  5. Decorrelation and efficient coding by retinal ganglion cells

    PubMed Central

    Pitkow, Xaq; Meister, Markus

    2013-01-01

    An influential theory of visual processing asserts that retinal center-surround receptive fields remove spatial correlations in the visual world, producing ganglion cell spike trains that are less redundant than the corresponding image pixels. For bright, high-contrast images, this decorrelation would enhance coding efficiency in optic nerve fibers of limited capacity. Here we test the central prediction of the theory and demonstrate that the spike trains of retinal ganglion cells are indeed decorrelated compared to the visual input. However, most of the decorrelation is accomplished not by the receptive fields, but by nonlinear processing in the retina. We show that a steep response threshold enhances efficient coding by noisy spike trains, and the effect of this nonlinearity is near optimal in both salamander and macaque retina. These results offer an explanation for the sparseness of retinal spike trains, and highlight the importance of treating the full nonlinear character of neural codes. PMID:22406548

  6. Colocalization of HCN Channel Subunits in Rat Retinal Ganglion Cells

    PubMed Central

    Stradleigh, Tyler W.; Ogata, Genki; Partida, Gloria J.; Oi, Hanako; Greenberg, Kenneth P.; Krempely, Kalen S.; Ishida, Andrew T.

    2011-01-01

    The current-passing pore of mammalian hyperpolarization-activated, cyclic nucleotide-gated ("HCN") channels is formed by subunit isoforms denoted HCN1-4. In various brain areas, antibodies directed against multiple isoforms bind to single neurons and the current ("Ih") passed during hyperpolarizations differs from that of heterologously expressed homomeric channels. By contrast, retinal rod, cone, and bipolar cells appear to use homomeric HCN channels. Here, we assess the generality of this pattern by examining HCN1 and HCN4 immunoreactivity in rat retinal ganglion cells, measuring Ih in dissociated cells, and testing whether HCN1 and HCN4 protein coimmunoprecipitate. Nearly half of the ganglion cells in whole-mounted retinae bound antibodies against both isoforms. Consistent with colocalization and physical association, 8-bromo-cAMP shifted the voltage-sensitivity of Ih less than that of HCN4 channels and more than that of HCN1 channels, and HCN1 coimmunoprecipitated with HCN4 from membrane fraction proteins. Lastly, the immunopositive somata ranged in diameter from the smallest to the largest in rat retina, the dendrites of immunopositive cells arborized at various levels of the inner plexiform layer and over fields of different diameters, and Ih activated with similar kinetics and proportions of fast and slow components in small, medium, and large somata. These results show that different HCN subunits colocalize in single retinal ganglion cells, identify a subunit that can reconcile native Ih properties with the previously reported presence of HCN4 in these cells, and indicate that Ih is biophysically similar in morphologically diverse retinal ganglion cells and differs from Ih in rods, cones, and bipolar cells. PMID:21456027

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

    PubMed

    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. PMID:26172189

  8. Extra-Articular Ganglion Cysts around the Knee Joint

    PubMed Central

    Park, Sang-Eun; Panchal, Karnav; Kim, Young-Yul; Ji, Jong-Hun; Park, Sung-Ryeoll; Park, Min-Kyu

    2015-01-01

    Purpose The purpose of this study was to report clinical results of open excision of extra-articular ganglion cysts around the knee joint combined with arthroscopic management of intra-articular pathologies if present. Materials and Methods Of the total 107 cases of cystic lesions around the knee, 23 cases of extra-articular ganglion cysts were reviewed between January 2006 and July 2011. There were 13 males and 10 females with a mean age of 48 years (range, 30 to 73 years). The mean follow-up duration was 40 months (range, 30 to 60 months). Preoperative magnetic resonance imaging (MRI) scan was done in all cases. Open surgical excision of the cyst was performed after arthroscopic management of intra-articular pathologies in all but 1 case. At the last follow-up, Lysholm and International Knee Documentation Committee (IKDC) scores were evaluated and MRI was conducted to detect recurrence. Results The mean Lysholm and IKDC scores showed significant improvement (p=0.005 and 0.013, respectively).The location of the cysts was anterior in 9, lateral in 7, medial in 6, and posterosuperior in 1. Intra-articular pathologies were found in 16/23 cases (69.6%). In 10/23 cases (43%), the cyst was connected to the knee joint. Three months postoperative MRI did not show any recurrence of ganglion cysts except for 1 case. Conclusions In the treatment of extra-articular ganglion cysts, MRI can be useful for detecting intra-articular lesions and connecting orifices, and arthroscopic management of intra-articular pathologies with open excision of the cyst should be considered as a viable treatment option. PMID:26672721

  9. Ganglion cyst in children: Reviewing treatment and recurrence rates

    PubMed Central

    Simon Cypel, Tatiana Karine; Mrad, Amir; Somers, Gino; Zuker, Ronald Melvin

    2011-01-01

    BACKGROUND: Pediatric hand and wrist ganglia seem to have different epidemiological characteristics than those of adults – a majority are found on the volar aspect of the hands and wrists of patients younger than 10 years of age. OBJECTIVE: To determine the epidemiology, etiological factors, clinical presentation, treatment and outcome of patients with ganglion cysts at The Hospital for Sick Children (Toronto, Ontario). METHODS: The records of the pathology department at The Hospital for Sick Children were searched for all cases of ganglion cyst operated on between January 2000 and December 2008. RESULTS: Thirty-seven patients underwent treatment for symptomatic ganglion cyst. The mean age of the patients was 9.6 years, and there were 23 females. A mobile nodule was the initial presentation of the ganglion in 64% of the cases. Pain was the most common indication for surgical removal. Only 11.4% of patients experienced previous trauma. In 70% of the cases, the diagnosis was made clinically. The most common sites of occurrence were volar wrist (25.7%), dorsal wrist (22.8%) and the volar aspect of the base of the ring finger (17.1%). Surgical excision was the treatment of choice for 94.2% of the patients with symptomatic lesions. The minimum follow-up period was 12 months. Only one patient (2.8%) presented with recurrence in the series. CONCLUSION: Although it is possible that these findings might change with longer follow-up, the present data provide information to help guide the treatment of these cysts. Complete surgical removal is a very effective treatment, with low rates of recurrence. PMID:22654533

  10. Intraneural ganglion cyst on the external popliteal nerve

    PubMed Central

    Rendon, Diego; Pescador, David; Cano, Carlos; Blanco, Juan

    2014-01-01

    There are many causes for the paralysis of the external sciatic popliteal nerve , such as the intraneural ganglion cyst. In this case, we evaluate a 52-year-old woman with no relevant personal record, who was admitted with paresis of the right foot of 4 months of evolution associated with alterations in the sensitivity that rose up to the posterolateral region of the leg. The diagnosis was based on MR and cyst decompression and disconnection of the articular branch. Given the low incidence of these lesions, their origin is still subject to controversy. The most widely accepted theory is the unifying articular theory described by Spinner in the year 2003. Intraneural ganglion cysts must be included in the differential diagnosis of progressive paralysis of the sciatic nerve, lesions of the nerve root at L5 and nerve sheath tumours that start at the lateral compartment of the knee. The treatment of a fibular intraneural ganglion cyst must be surgical and the operation must be performed as soon as possible. PMID:24891476

  11. White Matter Consequences of Retinal Receptor and Ganglion Cell Damage

    PubMed Central

    Ogawa, Shumpei; Takemura, Hiromasa; Horiguchi, Hiroshi; Terao, Masahiko; Haji, Tomoki; Pestilli, Franco; Yeatman, Jason D.; Tsuneoka, Hiroshi; Wandell, Brian A.; Masuda, Yoichiro

    2014-01-01

    Purpose. Patients with Leber hereditary optic neuropathy (LHON) and cone-rod dystrophy (CRD) have central vision loss; but CRD damages the retinal photoreceptor layer, and LHON damages the retinal ganglion cell (RGC) layer. Using diffusion MRI, we measured how these two types of retinal damage affect the optic tract (ganglion cell axons) and optic radiation (geniculo-striate axons). Methods. Adult onset CRD (n = 5), LHON (n = 6), and healthy controls (n = 14) participated in the study. We used probabilistic fiber tractography to identify the optic tract and the optic radiation. We compared axial and radial diffusivity at many positions along the optic tract and the optic radiation. Results. In both types of patients, diffusion measures within the optic tract and the optic radiation differ from controls. The optic tract change is principally a decrease in axial diffusivity; the optic radiation change is principally an increase in radial diffusivity. Conclusions. Both photoreceptor layer (CRD) and retinal ganglion cell (LHON) retinal disease causes substantial change in the visual white matter. These changes can be measured using diffusion MRI. The diffusion changes measured in the optic tract and the optic radiation differ, suggesting that they are caused by different biological mechanisms. PMID:25257055

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

    PubMed

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

    2013-01-01

    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. PMID:22844874

  13. [Phototransduction mediated by melanopsin in intrinsically photosensitive retinal ganglion cells].

    PubMed

    Domínguez-Solís, Carlos Augusto; Pérez-León, Jorge Alberto

    2015-01-01

    Melanopsin is the most recent photopigment described. As all the other opsins, it attaches in the retina as chromophore. Its amino acid sequence resembles more invertebrate opsins than those of vertebrates. The signal transduction pathway of opsins in vertebrates is based on the coupling to the G protein transducin, triggering a signaling cascade that results in the hyperpolarization of the plasma membrane. On the contrary, the photoreceptors of invertebrates activate the Gq protein pathway, which leads to depolarizing responses. Phototransduction mediated by melanopsin leads to the depolarization of those cells where it is expressed, the intrinsically photosensitive retinal ganglion cells; the cellular messengers and the ion channel type(s) responsible for the cells´ response is still unclear. Studies to elucidate the signaling cascade of melanopsin in heterologous expression systems, in retina and isolated/cultured intrinsically photosensitive retinal ganglion cells, have provided evidence for the involvement of protein Gq and phospholipase C together with the likely participation of an ion channel member of the transient receptor potential-canonical family, a transduction pathway similar to invertebrate photopigments, particularly Drosophila melanogaster. The intrinsically photosensitive retinal ganglion cells are the sole source of retinal inferences to the suprachiasmatic nucleus; thus, clarifying completely the melanopsin signaling pathway will impact the chronobiology field, including the clinical aspects. PMID:26581535

  14. Pediatric ganglion cysts of the hand and wrist: an epidemiologic analysis.

    PubMed

    Coffey, Michael J; Rahman, M Fazlur; Thirkannad, Sunil M

    2008-12-01

    We analyzed all hand and wrist ganglions in patients aged 12 years and younger that were treated at our institution during a 3-year period. Our patients were predominately female (1.8:1). Volar ganglions were more common (1.2:1), whereas dorsal ganglions have been reported to be more common in adults. Ganglions had a higher incidence of arising from tendon sheaths in our patients (33%) compared to what has been previously reported for ganglions in studies of all age groups (5% to 16%). While observation and/or splinting alone will likely be helpful in resolution of a majority of pediatric hand and wrist ganglions, surgical excision should be employed in those that are symptomatic and/or do not resolve with observation. PMID:18780007

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

    PubMed

    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

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

    PubMed Central

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

    2016-01-01

    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

  17. Surgical treatment of temporomandibular disorder in a 24-year-old male patient with ganglion cyst.

    PubMed

    Zheng, Zhi Wei; Shao, Xia; Yang, Chi; Fang, Yi Ming

    2015-03-01

    Ganglion cysts are common pseudocystic masses, whereas those arising from the temporomandibular joint (TMJ) are rare entities. We report a case of ganglion cyst of the right TMJ with symptomatic bilateral TMJ internal derangement in a 24-year-old man. Disk repositioning using bone anchors and excision of the ganglion cyst were performed. A unique characteristic of inflammatory infiltrates was revealed in the specimen, and the relationship between these 2 distinct entities and probable pathogenesis of infectious involvement are discussed. PMID:25643336

  18. Total absorption by degenerate critical coupling

    SciTech Connect

    Piper, Jessica R. Liu, Victor; Fan, Shanhui

    2014-06-23

    We consider a mirror-symmetric resonator with two ports. We show that, when excited from a single port, complete absorption can be achieved through critical coupling to degenerate resonances with opposite symmetry. Moreover, any time two resonances with opposite symmetry are degenerate in frequency and absorption is always significantly enhanced. In contrast, when two resonances with the same symmetry are nearly degenerate, there is no absorption enhancement. We numerically demonstrate these effects using a graphene monolayer on top of a photonic crystal slab, illuminated from a single side in the near-infrared.

  19. A Monte Carlo algorithm for degenerate plasmas

    SciTech Connect

    Turrell, A.E. Sherlock, M.; Rose, S.J.

    2013-09-15

    A procedure for performing Monte Carlo calculations of plasmas with an arbitrary level of degeneracy is outlined. It has possible applications in inertial confinement fusion and astrophysics. Degenerate particles are initialised according to the Fermi–Dirac distribution function, and scattering is via a Pauli blocked binary collision approximation. The algorithm is tested against degenerate electron–ion equilibration, and the degenerate resistivity transport coefficient from unmagnetised first order transport theory. The code is applied to the cold fuel shell and alpha particle equilibration problem of inertial confinement fusion.

  20. Advances in the management of macular degeneration

    PubMed Central

    2014-01-01

    Current management of age-related macular degeneration (AMD) can be divided into two categories: first, anti-vasoendothelial growth factor (anti-VEGF) injection for wet macular degeneration; second, anti-oxidant vitamins for dry macular degeneration. New therapies are being developed for both of these diseases using novel technologies and different modes of administration. The hope is that some of these therapies will achieve significant improvement to current management and prevent future loss of vision in this devastating eye condition. PMID:24860651

  1. Ganglion cyst of the foot treated with electroacupuncture: A case report

    PubMed Central

    Woitzik, Erin; Kissel, Jaclyn

    2013-01-01

    Objective: To present the clinical management of a ganglion cyst presenting on the dorsolateral aspect of the foot. Clinical Features: A 45-year-old female cyclist complaining of ganglion cyst following training period. Intervention and Outcome: Patient was treated with high-frequency electroacupuncture in four consecutive sessions over four weeks, and reported resolution of the cyst following therapeutic intervention. Conclusions: Ganglion cysts of the foot are relatively rare connective tissue tumours with variable treatment approaches. Electroacupuncture may be a novel and non-invasive conservative approach for the treatment of ganglion cysts. Further evaluation of the efficacy of such treatment is warranted. PMID:24302778

  2. The efficiency of design-based stereology in estimating spiral ganglion populations in mice

    PubMed Central

    Schettino, Amy E.; Lauer, Amanda M.

    2013-01-01

    Accurate quantification of cell populations is essential in assessing and evaluating neural survival and degeneration in experimental groups. Estimates obtained through traditional two-dimensional counting methods are heavily biased by the counting parameters in relation to the size and shape of the neurons to be counted, resulting in a large range of inaccurate counts. In contrast, counting every cell in a population can be extremely labor-intensive. The present study hypothesizes that design-based stereology provides estimates of the total number of cochlear spiral ganglion neurons (SGNs) in mice that are comparable to those obtained by other accurate cell-counting methods, such as a serial reconstruction, while being a more efficient method. SGNs are indispensable for relaying auditory information from hair cells to the auditory brainstem, and investigating factors affecting their degeneration provides insight into the physiological basis for the progression of hearing dysfunction. Stereological quantification techniques offer the benefits of efficient sampling that is independent of the size and shape of the SGNs. Population estimates of SGNs in cochleae from young C57 mice with normal-hearing and C57 mice with age-related hearing loss were obtained using the optical fractionator probe and traditional two-dimensional counting methods. The average estimated population of SGNs in normal-hearing mice was 7009, whereas the average estimated population in mice with age-related hearing loss was 5096. The estimated population of SGNs in normal-hearing mice fell within the range of values previously reported in the literature. The reduction in the SGN population in animals with age-related hearing loss was statistically significant. Stereological measurements required less time per section compared to two-dimensional methods while optimizing the amount of cochlear tissue analyzed. These findings demonstrate that design-based stereology provides a practical alternative

  3. Dispersion relations in weakly degenerate plasmas

    NASA Astrophysics Data System (ADS)

    Rocchi, F.; Molinari, V. G.; Mostacci, D.; Sumini, M.

    2001-06-01

    From a quantum mechanical point of view, electrons in laser produced plasmas can be regarded as weakly degenerate. For instance, for a plasma with electron density of 10 22 cm -3 and electron temperature of 1 eV, Sommerfeld's parameter is between 1 and 2. Under these conditions the usual dispersion relations for waves in plasmas need be corrected to account for degeneracy. In the present work, starting from the transport equation with a simplified version of the Boltzmann-Uehling-Uhlenbeck collision kernel the propagation of waves impinging on a plasma with weakly degenerate electrons is investigated and dispersion relations accounting for degeneracy are derived. These dispersion relations give the classical ones in the limit for Sommerfeld's parameter approaching zero. A shift of the wavenumber value and a non-collisional damping due to degeneracy effects are predicted which render a weakly degenerate plasma more opaque to radiation than a non-degenerate one.

  4. Degenerate neuronal systems sustaining cognitive functions

    PubMed Central

    Noppeney, Uta; Friston, Karl J; Price, Cathy J

    2004-01-01

    The remarkable resilience of cognitive functions to focal brain damage suggests that multiple degenerate neuronal systems can sustain the same function either via similar mechanisms or by implementing different cognitive strategies. In degenerate functional neuroanatomy, multiple degenerate neuronal systems might be present in a single brain where they are either co-activated or remain latent during task performance. In degeneracy over subjects, a particular function may be sustained by only one neuronal system within a subject, but by different systems over subjects. Degeneracy over subjects might have arisen from (ab)normal variation in neurodevelopmental trajectories or long-term plastic changes following structural lesions. We discuss how degenerate neuronal systems can be revealed using (1) intersubject variability, (2) multiple lesion studies and (3) an iterative approach integrating information from lesion and functional imaging studies. PMID:15610392

  5. Blockade of pathological retinal ganglion cell hyperactivity improves optogenetically evoked light responses in rd1 mice

    PubMed Central

    Barrett, John M.; Degenaar, Patrick; Sernagor, Evelyne

    2015-01-01

    Retinitis pigmentosa (RP) is a progressive retinal dystrophy that causes visual impairment and eventual blindness. Retinal prostheses are the best currently available vision-restoring treatment for RP, but only restore crude vision. One possible contributing factor to the poor quality of vision achieved with prosthetic devices is the pathological retinal ganglion cell (RGC) hyperactivity that occurs in photoreceptor dystrophic disorders. Gap junction blockade with meclofenamic acid (MFA) was recently shown to diminish RGC hyperactivity and improve the signal-to-noise ratio (SNR) of RGC responses to light flashes and electrical stimulation in the rd10 mouse model of RP. We sought to extend these results to spatiotemporally patterned optogenetic stimulation in the faster-degenerating rd1 model and compare the effectiveness of a number of drugs known to disrupt rd1 hyperactivity. We crossed rd1 mice with a transgenic mouse line expressing the light-sensitive cation channel channelrhodopsin2 (ChR2) in RGCs, allowing them to be stimulated directly using high-intensity blue light. We used 60-channel ITO multielectrode arrays to record ChR2-mediated RGC responses from wholemount, ex-vivo retinas to full-field and patterned stimuli before and after application of MFA, 18-β-glycyrrhetinic acid (18BGA, another gap junction blocker) or flupirtine (Flu, a Kv7 potassium channel opener). All three drugs decreased spontaneous RGC firing, but 18BGA and Flu also decreased the sensitivity of RGCs to optogenetic stimulation. Nevertheless, all three drugs improved the SNR of ChR2-mediated responses. MFA also made it easier to discern motion direction of a moving bar from RGC population responses. Our results support the hypothesis that reduction of pathological RGC spontaneous activity characteristic in retinal degenerative disorders may improve the quality of visual responses in retinal prostheses and they provide insights into how best to achieve this for optogenetic prostheses

  6. Blockade of pathological retinal ganglion cell hyperactivity improves optogenetically evoked light responses in rd1 mice.

    PubMed

    Barrett, John M; Degenaar, Patrick; Sernagor, Evelyne

    2015-01-01

    Retinitis pigmentosa (RP) is a progressive retinal dystrophy that causes visual impairment and eventual blindness. Retinal prostheses are the best currently available vision-restoring treatment for RP, but only restore crude vision. One possible contributing factor to the poor quality of vision achieved with prosthetic devices is the pathological retinal ganglion cell (RGC) hyperactivity that occurs in photoreceptor dystrophic disorders. Gap junction blockade with meclofenamic acid (MFA) was recently shown to diminish RGC hyperactivity and improve the signal-to-noise ratio (SNR) of RGC responses to light flashes and electrical stimulation in the rd10 mouse model of RP. We sought to extend these results to spatiotemporally patterned optogenetic stimulation in the faster-degenerating rd1 model and compare the effectiveness of a number of drugs known to disrupt rd1 hyperactivity. We crossed rd1 mice with a transgenic mouse line expressing the light-sensitive cation channel channelrhodopsin2 (ChR2) in RGCs, allowing them to be stimulated directly using high-intensity blue light. We used 60-channel ITO multielectrode arrays to record ChR2-mediated RGC responses from wholemount, ex-vivo retinas to full-field and patterned stimuli before and after application of MFA, 18-β-glycyrrhetinic acid (18BGA, another gap junction blocker) or flupirtine (Flu, a Kv7 potassium channel opener). All three drugs decreased spontaneous RGC firing, but 18BGA and Flu also decreased the sensitivity of RGCs to optogenetic stimulation. Nevertheless, all three drugs improved the SNR of ChR2-mediated responses. MFA also made it easier to discern motion direction of a moving bar from RGC population responses. Our results support the hypothesis that reduction of pathological RGC spontaneous activity characteristic in retinal degenerative disorders may improve the quality of visual responses in retinal prostheses and they provide insights into how best to achieve this for optogenetic prostheses

  7. Quantitative Pfirrmann Disc Degeneration Grading System to Overcome the Limitation of Pfirrmann Disc Degeneration Grade

    PubMed Central

    2016-01-01

    Objective Pfirrmann disc degeneration grade is one of morphologic disc degeneration grading system and it was reliable on routine T2-weighted magnetic resonance (MR) images. The purpose of this study was to evaluate the agreement of Pfirrmann disc degeneration grade, and check the alternative technique of disc degeneration grading system. Methods Fifteen volunteers (4 medical doctors related to spinal disease, 2 medical doctors not related to spinal disease, 6 nurses in spinal hospital, and 3 para-medicines) were included in this study. Three different digitalized MR images were provided all volunteers, and they checked Pfirrmann disc degeneration grade of each disc levels after careful listening to explanation. Indeed, all volunteers checked the signal intensity of disc degeneration at the points of nucleus pulposus (NP), disc membrane, ligaments, fat, and air to modify the quantitative Pfirrmann disc degeneration grade. Results Total 225 grade results of Pfirrmann disc degeneration grade and 405 signal intensity results of quantitative Pfirrmann disc degeneration grade were analyzed. Average interobserver agreement was "moderate (mean±standard deviation, 0.575±0.251)" from poor to excellent. Completely agreed levels of Pfirrmann disc degeneration grade were only 4 levels (26.67%), and the disagreement levels were observed in 11 levels; two different grades in 8 levels (53.33%) and three different grades in 3 levels (20%). Quantitative Pfirrmann disc degeneration showed relatively cluster distribution with the interobserver deviations of 0.41-1.56 at the ratio of NP and disc membrane, and it showed relatively good cluster and distribution indicating that the proposed grading system has good discrimination ability. Conclusion Pfirrmann disc degeneration grade showed the limitation of different interobserver results, but this limitation could be overcome by using quantitative techniques of MR signal intensity. Further evaluation is needed to access its advantage

  8. Frontotemporal lobar degeneration: current perspectives

    PubMed Central

    Riedl, Lina; Mackenzie, Ian R; Förstl, Hans; Kurz, Alexander; Diehl-Schmid, Janine

    2014-01-01

    The term frontotemporal lobar degeneration (FTLD) refers to a group of progressive brain diseases, which preferentially involve the frontal and temporal lobes. Depending on the primary site of atrophy, the clinical manifestation is dominated by behavior alterations or impairment of language. The onset of symptoms usually occurs before the age of 60 years, and the mean survival from diagnosis varies between 3 and 10 years. The prevalence is estimated at 15 per 100,000 in the population aged between 45 and 65 years, which is similar to the prevalence of Alzheimer’s disease in this age group. There are two major clinical subtypes, behavioral-variant frontotemporal dementia and primary progressive aphasia. The neuropathology underlying the clinical syndromes is also heterogeneous. A common feature is the accumulation of certain neuronal proteins. Of these, the microtubule-associated protein tau (MAPT), the transactive response DNA-binding protein, and the fused in sarcoma protein are most important. Approximately 10% to 30% of FTLD shows an autosomal dominant pattern of inheritance, with mutations in the genes for MAPT, progranulin (GRN), and in the chromosome 9 open reading frame 72 (C9orf72) accounting for more than 80% of familial cases. Although significant advances have been made in recent years regarding diagnostic criteria, clinical assessment instruments, neuropsychological tests, cerebrospinal fluid biomarkers, and brain imaging techniques, the clinical diagnosis remains a challenge. To date, there is no specific pharmacological treatment for FTLD. Some evidence has been provided for serotonin reuptake inhibitors to reduce behavioral disturbances. No large-scale or high-quality studies have been conducted to determine the efficacy of non-pharmacological treatment approaches in FTLD. In view of the limited treatment options, caregiver education and support is currently the most important component of the clinical management. PMID:24600223

  9. Signaling Networks of Retinal Ganglion Cell Formation and the Potential Application of Stem Cell-Based Therapy in Retinal Degenerative Diseases.

    PubMed

    Wu, Nan; Wang, Yi; Yang, Lanbo; Cho, Kin-Sang

    2016-08-01

    Retinal degenerative diseases such as age-related macular degeneration, retinitis pigmentosa, and glaucoma result in permanent loss of retinal neurons and vision. Stem cell therapy could be a novel treatment strategy to restore visual function. In an ideal situation, a homogenous population of stem cell-derived retinal neurons with high purity is used for replacement therapy. Thus, it is crucial to elucidate the molecular mechanisms that regulate the development of retinal progenitor cells and subsequent generation of specific retinal neurons. Here, recent findings concerning the intrinsic and extrinsic factors that regulate retinal progenitor cell maintenance and differentiation are summarized, especially transcriptional factors and extrinsic signals. Understanding these mechanisms is indispensable because they have potential clinical applications, chiefly the generation of specific retinal cells such as retinal ganglion cells to treat glaucoma and other optic neuropathy diseases. PMID:27466076

  10. Canine Retina Has a Primate Fovea-Like Bouquet of Cone Photoreceptors Which Is Affected by Inherited Macular Degenerations

    PubMed Central

    Guziewicz, Karina E.; Iwabe, Simone; Swider, Malgorzata; Scott, Erin M.; Savina, Svetlana V.; Ruthel, Gordon; Stefano, Frank; Zhang, Lingli; Zorger, Richard; Sumaroka, Alexander; Jacobson, Samuel G.; Aguirre, Gustavo D.

    2014-01-01

    Retinal areas of specialization confer vertebrates with the ability to scrutinize corresponding regions of their visual field with greater resolution. A highly specialized area found in haplorhine primates (including humans) is the fovea centralis which is defined by a high density of cone photoreceptors connected individually to interneurons, and retinal ganglion cells (RGCs) that are offset to form a pit lacking retinal capillaries and inner retinal neurons at its center. In dogs, a local increase in RGC density is found in a topographically comparable retinal area defined as the area centralis. While the canine retina is devoid of a foveal pit, no detailed examination of the photoreceptors within the area centralis has been reported. Using both in vivo and ex vivo imaging, we identified a retinal region with a primate fovea-like cone photoreceptor density but without the excavation of the inner retina. Similar anatomical structure observed in rare human subjects has been named fovea-plana. In addition, dogs with mutations in two different genes, that cause macular degeneration in humans, developed earliest disease at the newly-identified canine fovea-like area. Our results challenge the dogma that within the phylogenetic tree of mammals, haplorhine primates with a fovea are the sole lineage in which the retina has a central bouquet of cones. Furthermore, a predilection for naturally-occurring retinal degenerations to alter this cone-enriched area fills the void for a clinically-relevant animal model of human macular degenerations. PMID:24599007

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

    PubMed Central

    Greferath, Ursula; Anderson, Emily E.; Jobling, Andrew I.; Vessey, Kirstan A.; Martinez, Gemma; de Iongh, Robb U.; Kalloniatis, Michael; Fletcher, Erica L.

    2015-01-01

    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 2–12 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 glial fibrillary acidic protein 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. PMID:26283925

  12. Ganglionic transmission in a vasomotor pathway studied in vivo

    PubMed Central

    Bratton, Bradford; Davies, Philip; Jänig, Wilfrid; McAllen, Robin

    2010-01-01

    Intracellular recordings were made in vivo from 40 spontaneously active cells in the third lumbar sympathetic ganglion of urethane-anaesthetized rats. In 38/40 cells ongoing action potentials showed strong cardiac rhythmicity (93.4 ± 1.9% modulation) indicating high barosensitivity and probable muscle vasoconstrictor (MVC) function. Subthreshold excitatory postsynaptic potentials (EPSPs) showed the same pattern. The 38 barosensitive neurons fired action potentials at 2.9 ± 0.3 Hz. All action potentials were triggered by EPSPs, most of which were unitary events. Calculations indicated that <5% of action potentials were triggered by summation of otherwise subthreshold EPSPs. ‘Dominant’ synaptic inputs with a high safety factor were identified, confirming previous work. These were active in 24/38 cells and accounted for 32% of all action potentials; other (‘secondary’) inputs drove the remainder. Inputs (21 dominant, 19 secondary) attributed to single preganglionic neurons fired at 1.38 ± 0.16 Hz. An average of two to three preganglionic neurons were estimated to drive each ganglion cell's action potentials. When cells were held hyperpolarized to block spiking, a range of spontaneous EPSP amplitudes was revealed. Threshold equivalent was defined as the membrane potential value that was exceeded by spontaneous EPSPs at the same frequency as the cell's original firing rate. In 10/12 cells examined, a continuum of EPSP amplitudes overlapped threshold equivalent. Small changes in cell excitability could therefore raise or lower the percentage of preganglionic inputs triggering action potentials. The results indicate that vasoconstrictor ganglion cells in vivo mostly behave not as 1:1 relays, but as continuously variable gates. PMID:20308254

  13. Attempted reversible sympathetic ganglion block by an implantable neurostimulator

    PubMed Central

    Kopelman, Doron; Costa, Mario G.; Bejar, Jacob; Zaretsky, Asaph; Hashmonai, Moshe

    2012-01-01

    OBJECTIVE Primary palmar hyperhidrosis is a pathological condition of excessive perspiration of the hands of unknown aetiology. The only effective treatment for permanent cure is the ablation of the sympathetic ganglia supplying the hands. One of the sequelae is compensatory sweating, namely increased perspiration in other parts of the body. Its mechanism is unknown. In a small proportion of patients, it may attend devastating proportions. It has practically no remedy, and the degree of compensatory hyperhidrosis is unpredictable prior to sympathectomy. The purpose of the present study was to obtain a reversible sympathetic block which may disclose subjects prone to develop severe compensatory hyperhidrosis and unfit for permanent ganglionic ablation. METHODS In three dogs, an experimental electrode was implanted via a left thoracotomy on the stellate ganglion, connected to a stimulator. The stimulation was activated after recovery. The contralateral ganglion served as control. Effect of the stimulation was assessed by observing the development of Horner's syndrome, which includes the appearance of miosis, ptosis and enophthalmus. Reversal of the sympathetic block was expected when the neurostimulation was discontinued and assessed by the disappearance of these signs. RESULTS Stimulation produced only a partial effect – an incomplete Horner's syndrome (miosis and sometime ptosis), which was not completely reversible after ceasing the stimulation. CONCLUSIONS Although neurostimulation achieved a partial sympathetic block, the present method failed to obtain a completely reversible effect. However, these results may indicate that different nervous pathways moderate the various components of the Horner's triad. Concerning the creation of a reversible sympathectomy; other approaches must be sought after. PMID:22316522

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

    PubMed Central

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

    2016-01-01

    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. PMID:27064785

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

    PubMed

    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. PMID:27064785

  16. Intraosseous ganglion cysts of the carpus: current practice.

    PubMed

    Osagie, Liza; Gallivan, Samantha; Wickham, Neil; Umarji, Shamim

    2015-12-01

    Intraosseous cysts of the carpal bones are an infrequent cause of chronic wrist pain. The main body of work has investigated their occurrence in the proximal carpus, with limited incidence in the distal row. We review the current literature on the treatment of symptomatic carpal cysts following the report of a 17-year-old male with a 12-month history of progressive right wrist pain due to an intraosseous ganglion of the trapezoid. This review explores the pathology of carpal cysts, their varying presentation and current treatments. PMID:26568710

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

    PubMed

    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. PMID:23494753

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

    PubMed

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

    2015-02-01

    The sympathetic ganglion contains small intensely fluorescent (SIF) cells derived from the neural crest. We morphologically characterize SIF cells and focus on their relationship with ganglionic cells, preganglionic nerve fibers and sensory nerve endings. SIF cells stained intensely for tyrosine hydroxylase (TH), with a few cells also being immunoreactive for dopamine 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. PMID:25416508

  19. Midline lumbar ganglion/synovial cyst mimicking an epidural tumor: case report and review of pathogenesis.

    PubMed

    Azzam, C J

    1988-08-01

    A case of a midline lumbar extradural ganglion/synovial cyst causing lumbar canal stenosis and mimicking an epidural tumor is presented. The lesion was demonstrated by a magnetic resonance imaging study, and relief of symptoms was achieved with decompressive laminectomy and total removal of the mass. The pathogenesis of lumbar ganglion/synovial cyst is reviewed. PMID:2972941

  20. Deep Peroneal Nerve Palsy Caused by an Extraneural Ganglion Cyst: A Rare Case

    PubMed Central

    Nikolopoulos, Dimitrios; Safos, George; Sergides, Neoptolemos; Safos, Petros

    2015-01-01

    Lower extremities peripheral neuropathies caused by ganglion cysts are rare. The most frequent location of occurrence is the common peroneal nerve and its branches, at the level of the fibular neck. We report the case of a 57-year-old patient admitted with foot drop, due to an extraneural ganglion of the upper tibiofibular syndesmosis, compressing the deep branch of the peroneal nerve. Although there have been many previous reports of intraneural ganglion involvement with the lower limb nerves, to our knowledge, this is the second reported occurrence of an extraneural ganglion distinctly localized to the upper tibiofibular syndesmosis and palsying deep peroneal nerve. The diagnosis was made preoperatively using MRI. The common peroneal nerve and its branches were recognized and traced to its bifurcation during the operation, and the ganglion cyst was removed. Two months after surgery, the patient was pain-free and asymptomatic except for cutaneous anesthesia in the distribution of the deep peroneal nerve. PMID:25632363

  1. The simple wrist ganglion--more than a minor surgical procedure?

    PubMed

    Faithfull, D K; Seeto, B G

    2000-12-01

    The operative results of 59 wrist ganglions over a ten-year period are reported. The mean follow-up time was 65 months (range: 6-133). The indication for operation was pre-operative pain in 68% of cases (40 ganglions) and cosmetic deformity in 32% of cases (19 ganglions). There were six recurrences (10%) at a mean duration of 40 months post-operatively (range: 5-70). There was no statistical differences between recurrences comparing dorsal versus volar ganglions using the chi-squared analysis. Two occult recurrences were detected on follow-up ultrasound examination giving an overall recurrence rate of 14%. Despite 92% of patients being satisfied with the operative procedure, there were 16 patients (28%) who had either persistent pain, limitation of function, were unsatisfied or had a recurrence. These results show that treatment of a simple ganglion is more than just a minor operation. PMID:11301508

  2. Wrist joint ganglion presenting as a painless mass in the palm: report of 2 cases.

    PubMed

    Cornwall, Roger; Koris, Mark J; Jupiter, Jesse B

    2004-03-01

    Ganglions occur commonly in the wrist and arise from the radiocarpal and intercarpal joints. Although ganglions present commonly as masses on the dorsal or volar surface of the wrist, ganglions from wrist joints appear rarely at other locations in the hand. We report 2 cases of ganglions arising from wrist joints that presented as painless masses in the center of the palm without signs or symptoms of median or ulnar nerve compression. Surgical treatment required extensile exposure to trace the proximal stalks to their joints of origin. Knowledge of the possibility that a painless mass in the palm could be a ganglion arising from a joint in the wrist allows proper presurgical planning and informed consent. PMID:15043903

  3. Large lateral meniscal ganglion cyst extending into the intercondylar fossa of the knee.

    PubMed

    Jäger, Alwin; Eberhardt, Christian; Hailer, Nils P

    2004-07-01

    We report the case of a 31-year-old, otherwise healthy man with a large intra-articular meniscal ganglion cyst (27.7 x 13.5 mm) originating from the dorsal horn of the lateral meniscus. Clinically, the patient presented with knee pain in a squatting position. Magnetic resonance imaging revealed a large intra-articular cyst in the posterior compartment. At arthroscopic surgery, the ganglion cyst was found in the intercondylar space posteriorly to the posterior cruciate ligament. After removal of the ganglion cyst, a horizontal tear in the dorsal horn of the lateral meniscus was revealed and treated by partial meniscectomy. To our knowledge, a meniscal ganglion cyst originating from the lateral meniscus and extending into the joint is an extremely rare event, with only two previous reported cases. We review the current literature on the pathogenesis, distribution, and treatment of meniscal ganglion cysts. PMID:15243414

  4. Deep peroneal nerve palsy caused by an extraneural ganglion cyst: a rare case.

    PubMed

    Nikolopoulos, Dimitrios; Safos, George; Sergides, Neoptolemos; Safos, Petros

    2015-01-01

    Lower extremities peripheral neuropathies caused by ganglion cysts are rare. The most frequent location of occurrence is the common peroneal nerve and its branches, at the level of the fibular neck. We report the case of a 57-year-old patient admitted with foot drop, due to an extraneural ganglion of the upper tibiofibular syndesmosis, compressing the deep branch of the peroneal nerve. Although there have been many previous reports of intraneural ganglion involvement with the lower limb nerves, to our knowledge, this is the second reported occurrence of an extraneural ganglion distinctly localized to the upper tibiofibular syndesmosis and palsying deep peroneal nerve. The diagnosis was made preoperatively using MRI. The common peroneal nerve and its branches were recognized and traced to its bifurcation during the operation, and the ganglion cyst was removed. Two months after surgery, the patient was pain-free and asymptomatic except for cutaneous anesthesia in the distribution of the deep peroneal nerve. PMID:25632363

  5. Ganglion and Synovial Cyst of the Temporomandibular Joint: A Case Report and Literature Review

    PubMed Central

    Hofstede, Diederik J.

    2015-01-01

    Summary: Ganglion and synovial cysts of the temporomandibular joint (TMJ) are rare. Although histopathological findings differ, clinical presentation is comparable. This study adds a case report of a ganglion of the TMJ to existing literature and a review of all available case reports on ganglion and synovial cysts of the TMJ. Including our own case report, we reviewed 49 cases of ganglion and synovial cysts of the TMJ. They occurred in a female:male ratio of 3:1, at an median age of 46 years (range, 11–64 years). Patients mainly presented with preauricular swelling and pain. After imaging, the ganglion or synovial cyst was most commonly excised under general anesthesia. No recurrences were described. PMID:26495237

  6. Ganglion and Synovial Cyst of the Temporomandibular Joint: A Case Report and Literature Review.

    PubMed

    Steen, M Willemijn; Hofstede, Diederik J

    2015-09-01

    Ganglion and synovial cysts of the temporomandibular joint (TMJ) are rare. Although histopathological findings differ, clinical presentation is comparable. This study adds a case report of a ganglion of the TMJ to existing literature and a review of all available case reports on ganglion and synovial cysts of the TMJ. Including our own case report, we reviewed 49 cases of ganglion and synovial cysts of the TMJ. They occurred in a female:male ratio of 3:1, at an median age of 46 years (range, 11-64 years). Patients mainly presented with preauricular swelling and pain. After imaging, the ganglion or synovial cyst was most commonly excised under general anesthesia. No recurrences were described. PMID:26495237

  7. Intraosseous Ganglion Cyst of Scaphoid treated by Curettage and Bone Grafting: Case report and Review

    PubMed Central

    Jain, Saurabh; Jain, Anil Kumar; Dhammi, Ish Kumar; Mishra, Puneet; Modi, Prasant

    2011-01-01

    Introduction: Intraosseous ganglions, although share same pathology as the soft tissue ganglions are rare entities, further rare in carpals. Cases of intraosseous ganglions are reported in literature mostly in lower limbs and lunate among carpals, with treatment options ranging from curettage and grafting to calcium phosphate cement injection and finally to arthroscopic treatment. Case report: Here, we present a case of 2 years follow up of 40 years old female with nonspecific clinical finding of wrist and slight limitation of restriction of motion, diagnosed as intraosseous ganglion cyst of scaphoid. This case was treated with curettage and bone grafting having excellent results with visual and analog pain scores reduced from 68 to 11 and range of motion was 90° extension to 80° flexion and full grip strength. Conclusion: Intraosseous ganglion cyst should be considered in differential diagnosis of chronic dull wrist pain because they produce disabling symptoms which ceases once adequately treated by curettage and bone grafting.

  8. Inhibiting Matrix Metalloproteinase 3 Ameliorates Neuronal Loss in the Ganglion Cell Layer of Rats in Retinal Ischemia/Reperfusion.

    PubMed

    Hu, Tu; You, Qiuting; Chen, Dan; Tong, Jianbin; Shang, Lei; Luo, Jia; Qiu, Yi; Yu, Huimin; Zeng, Leping; Huang, Jufang

    2016-05-01

    It has been demonstrated that matrix metalloproteinase 3 (MMP3) is integrally involved in the neuronal degeneration of the central nervous system by promoting glial activation, neuronal apoptosis and damage to the brain-blood barrier. However, whether MMP3 also contributes to the neuronal degeneration induced by retinal ischemia/reperfusion is still uncertain. In the present study, we detected the cellular localization of MMP3 in adult rat retinae and explored the relationship of its expression with neuronal loss in the ganglion cell layer (GCL) in retinal ischemia/reperfusion. We found that MMP3 was widely expressed in many cells throughout the layers of the rat retinae, including Vertebrate neuron-specific nuclear protein (NeuN)-, parvalbumin-, calbindin-, protein kinase C-α-, glial fibrillary acidic protein-, glutamine synthetase- and CD11b-positive cells. Furthermore, all rats were treated with high intraocular pressure (HIOP) for 1 h (h) and sacrificed at 6 h, 1 day (d), 3 d, and 7 d after HIOP. Compared to the normal control, the expression of both proenzyme MMP3 and active MMP3 were significantly up-regulated after HIOP treatment without alteration of the laminar distribution pattern. Moreover, inhibiting MMP3 ameliorated the loss of NeuN-positive cells in the GCL following HIOP. In summary, our data demonstrates that MMP3 is expressed in multiple types of neurons and glial cells in normal rat retinae. Simultaneously, the up-regulation of its expression and activity are closely involved in neuronal loss in the GCL in retinal ischemia/reperfusion. PMID:26830289

  9. Brain-derived neurotrophic factor promotes cochlear spiral ganglion cell survival and function in deafened, developing cats.

    PubMed

    Leake, Patricia A; Hradek, Gary T; Hetherington, Alexander M; Stakhovskaya, Olga

    2011-06-01

    Postnatal development and survival of spiral ganglion (SG) neurons depend on both neural activity and neurotrophic support. Our previous studies showed that electrical stimulation from a cochlear implant only partially prevents SG degeneration after early deafness. Thus, neurotrophic agents that might be combined with an implant to improve neural survival are of interest. Recent studies reporting that brain-derived neurotrophic factor (BDNF) promotes SG survival after deafness have been conducted in rodents and limited to relatively short durations. Our study examined longer duration BDNF treatment in deafened cats that may better model the slow progression of SG degeneration in human cochleae, and this is the first study of BDNF in the developing auditory system. Kittens were deafened neonatally, implanted at 4-5 weeks with intracochlear electrodes containing a drug-delivery cannula, and BDNF or artificial perilymph was infused for 10 weeks from a miniosmotic pump. In BDNF-treated cochleae, SG cells grew to normal size and were significantly larger than cells on the contralateral side. However, their morphology was not completely normal, and many neurons lacked or had thinned perikaryl myelin. Unbiased stereology was employed to estimate SG cell density, independent of cell size. BDNF was effective in promoting significantly improved survival of SG neurons in these developing animals. BDNF treatment also resulted in higher density and larger size of myelinated radial nerve fibers, sprouting of fibers into the scala tympani, and improvement of electrically evoked auditory brainstem response thresholds. BDNF may have potential therapeutic value in the developing auditory system, but many serious obstacles currently preclude clinical application. PMID:21452221

  10. Prospectives for Gene Therapy of Retinal Degenerations

    PubMed Central

    Thumann, Gabriele

    2012-01-01

    Retinal degenerations encompass a large number of diseases in which the retina and associated retinal pigment epithelial (RPE) cells progressively degenerate leading to severe visual disorders or blindness. Retinal degenerations can be divided into two groups, a group in which the defect has been linked to a specific gene and a second group that has a complex etiology that includes environmental and genetic influences. The first group encompasses a number of relatively rare diseases with the most prevalent being Retinitis pigmentosa that affects approximately 1 million individuals worldwide. Attempts have been made to correct the defective gene by transfecting the appropriate cells with the wild-type gene and while these attempts have been successful in animal models, human gene therapy for these inherited retinal degenerations has only begun recently and the results are promising. To the second group belong glaucoma, age-related macular degeneration (AMD) and diabetic retinopathy (DR). These retinal degenerations have a genetic component since they occur more often in families with affected probands but they are also linked to environmental factors, specifically elevated intraocular pressure, age and high blood sugar levels respectively. The economic and medical impact of these three diseases can be assessed by the number of individuals affected; AMD affects over 30 million, DR over 40 million and glaucoma over 65 million individuals worldwide. The basic defect in these diseases appears to be the relative lack of a neurogenic environment; the neovascularization that often accompanies these diseases has suggested that a decrease in pigment epithelium-derived factor (PEDF), at least in part, may be responsible for the neurodegeneration since PEDF is not only an effective neurogenic and neuroprotective agent but also a potent inhibitor of neovascularization. In the last few years inhibitors of vascularization, especially antibodies against vascular endothelial cell

  11. Antioxidative nanofullerol prevents intervertebral disk degeneration

    PubMed Central

    Yang, Xinlin; Jin, Li; Yao, Lu; Shen, Francis H; Shimer, Adam L; Li, Xudong

    2014-01-01

    Compelling evidence suggests that reactive oxygen species (ROS) play a pivotal role in disk degeneration. Fullerol nanoparticles prepared in aqueous solution have been demonstrated to have outstanding ability to scavenge ROS. In this report, in vitro and in vivo models were used to study the efficacy of fullerol in preventing disk degeneration. For in vitro experiments, a pro-oxidant H2O2 or an inflammatory cytokine interleukin (IL)-1β was employed to induce degenerated phenotypes in human nucleus pulposus cells encapsulated in alginate beads, and fullerol was added in the culture medium. For the animal study, an annulus-puncture model with rabbit was created, and fullerol was injected into disks. It was shown that cytotoxicity and cellular ROS level induced by H2O2 were significantly diminished by fullerol. IL-1β-induced nitric oxide generation in culture medium was suppressed by fullerol as well. Gene-profile and biochemical assays showed that fullerol effectively reversed the matrix degradation caused by either H2O2 or IL-1β. The animal study delineated that intradiskal injection of fullerol prevented disk degeneration, increasing water and proteoglycan content and inhibiting ectopic bone formation. These results suggest that antioxidative fullerol may have a potential therapeutic application for disk degeneration. PMID:24876775

  12. Types of Parvalbumin-Containing Retinotectal Ganglion Cells in Mouse

    PubMed Central

    Yi, Chae-Woo; Yu, Song-Hee; Lee, Eun-Shil; Lee, Jee-Geon; Jeon, Chang-Jin

    2012-01-01

    The calcium-binding protein parvalbumin (PV) occurs in the retinal ganglion cells (RGCs) of various vertebrate species. In the present study, we aimed to identify the types of PV-containing RGCs that project to the superior colliculus (SC) in the mouse. We injected retrograde tracer dextran into the mouse SC to label RGCs. PV-containing RGCs were first identified by immunocytochemistry and then neurons double-labeled with dextran and PV were iontophoretically injected with a lipophilic dye, DiI. Subsequently, confocal microscopy was used to characterize the morphologic classification of the PV-immunoreactive (IR) retinotectal ganglion cells on the basis of dendritic field size, branching pattern, and stratification within the inner plexiform layer. Among the 8 different types of PV-containing RGCs in the mouse retina, we found all 8 types of RGCs projecting to the SC. The RGCs were heterogeneous in morphology. The combined approach of using tracer injection and a single cell injection after immunocytochemistry on a particular protein will provide valuable data to further understand the functional features of the RGCs which constitute the retinotectal pathway. PMID:22829714

  13. The functional diversity of retinal ganglion cells in the mouse

    PubMed Central

    Baden, Tom; Berens, Philipp; Franke, Katrin; Rosón, Miroslav Román; Bethge, Matthias; Euler, Thomas

    2015-01-01

    SUMMARY In the vertebrate visual system, all output of the retina is carried by retinal ganglion cells. Each type encodes distinct visual features in parallel for transmission to the brain. How many such “output channels” exist and what each encodes is an area of intense debate. In mouse, anatomical estimates range between 15–20 channels, and only a handful are functionally understood. Combining two-photon calcium imaging to obtain dense retinal recordings and unsupervised clustering of the resulting sample of >11,000 cells, we here show that the mouse retina harbours substantially more than 30 functional output channels. These include all known and several new ganglion cell types, as verified by genetic and anatomical criteria. Therefore, information channels from the mouse’s eye to the mouse’s brain are considerably more diverse than shown thus far by anatomical studies, suggesting an encoding strategy resembling that used in state-of-the-art artificial vision systems. PMID:26735013

  14. Recurrent intraneural ganglion cysts: Pathoanatomic patterns and treatment implications.

    PubMed

    Desy, Nicholas M; Lipinski, Lindsay J; Tanaka, Shota; Amrami, Kimberly K; Rock, Michael G; Spinner, Robert J

    2015-11-01

    The etiology of intraneural ganglion cysts has been poorly understood. This has resulted in the development of multiple surgical treatment strategies and a high recurrence rate. We sought to analyze these recurrences in order to provide a pathoanatomic explanation and staging classification for intraneural cyst recurrence. An expanded literature search was performed to identify frequencies and patterns in cases of intraneural ganglion cyst recurrences following primary surgery. Two univariate analyses were completed to identify associations between the type of revision surgery and repeat cyst recurrences. The expanded literature search found an 11% recurrence rate following primary surgery, including 64 recurrences following isolated cyst decompression (Group 1); six after articular branch resection (Group 2); and none following surgical procedures that addressed the joint (Group 3). Eight cases did not specify the type of primary surgery. In group 1, forty-eight of the recurrences (75%) were in the parent nerve, three involved only the articular branch, and one travelled along the articular branch in a different distal direction without involving the main parent nerve. In group 2, only one case (17%) recurred/persisted within the parent nerve, one recurred within a persistent articular branch, and one formed within a persistent articular branch and travelled in a different distal direction. Intraneural recurrences most commonly occur following surgical procedures that only target the main parent nerve. We provide proven or theoretical explanations for all identified cases of intraneural recurrences for an occult or persistent articular branch pathway. PMID:26296291

  15. The cell stress machinery and retinal degeneration.

    PubMed

    Athanasiou, Dimitra; Aguilà, Monica; Bevilacqua, Dalila; Novoselov, Sergey S; Parfitt, David A; Cheetham, Michael E

    2013-06-27

    Retinal degenerations are a group of clinically and genetically heterogeneous disorders characterised by progressive loss of vision due to neurodegeneration. The retina is a highly specialised tissue with a unique architecture and maintaining homeostasis in all the different retinal cell types is crucial for healthy vision. The retina can be exposed to a variety of environmental insults and stress, including light-induced damage, oxidative stress and inherited mutations that can lead to protein misfolding. Within retinal cells there are different mechanisms to cope with disturbances in proteostasis, such as the heat shock response, the unfolded protein response and autophagy. In this review, we discuss the multiple responses of the retina to different types of stress involved in retinal degenerations, such as retinitis pigmentosa, age-related macular degeneration and glaucoma. Understanding the mechanisms that maintain and re-establish proteostasis in the retina is important for developing new therapeutic approaches to fight blindness. PMID:23684651

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

    PubMed

    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. PMID:20951131

  17. Loss of osteoprotegerin expression in the inner ear causes degeneration of the cochlear nerve and sensorineural hearing loss.

    PubMed

    Kao, Shyan-Yuan; Kempfle, Judith S; Jensen, Jane B; Perez-Fernandez, Deborah; Lysaght, Andrew C; Edge, Albert S; Stankovic, Konstantina M

    2013-08-01

    Osteoprotegerin (OPG) is a key regulator of bone remodeling. Mutations and variations in the OPG gene cause many human diseases that are characterized by not only skeletal abnormalities but also poorly understood hearing loss: Paget's disease, osteoporosis, and celiac disease. To gain insight into the mechanisms of hearing loss in OPG deficiency, we studied OPG knockout (Opg(-/-)) mice. We show that they develop sensorineural hearing loss, in addition to conductive hearing loss due to abnormal middle-ear bones. OPG deficiency caused demyelination and degeneration of the cochlear nerve in vivo. It also activated ERK, sensitized spiral ganglion cells (SGC) to apoptosis, and inhibited proliferation and survival of cochlear stem cells in vitro, which could be rescued by treatment with exogenous OPG, an ERK inhibitor, or bisphosphonate. Our results demonstrate a novel role for OPG in the regulation of SGC survival, and suggest a mechanism for sensorineural hearing loss in OPG deficiency. PMID:23607938

  18. Potential Outcome Factors in Subacute Combined Degeneration

    PubMed Central

    Vasconcelos, Olavo M; Poehm, Erika H; McCarter, Robert J; Campbell, William W; Quezado, Zenaide M N

    2006-01-01

    BACKGROUND Subacute combined degeneration is an acquired myelopathy caused by vitamin B12 deficiency. Therapy with B12 leads to improvement in most but to complete recovery in only a few patients. Prognostic indicators in subacute combined degeneration are unknown; therefore, predicting complete recovery of neurologic deficits is challenging. PURPOSE To identify potential correlates of outcome and to generate hypotheses concerning predictors of complete resolution of neurologic deficits in subacute combined degeneration. DATA SOURCE We searched EMBASE (1974 to October 2005), MEDLINE (1968 to October 2005), and references from identified reports. REPORTS SELECTION Reports of patients with subacute combined degeneration containing results of magnetic resonance imaging (MRI) and description of outcome and 1 patient treated by the authors. DATA EXTRACTION, SYNTHESIS We extracted data from 45 reports and 57 patients (36 males, 21 females; age range: 10 to 81) with a diagnosis of subacute combined degeneration, and estimated the strength of association between clinical, laboratory, and radiological factors and complete resolution of signs and symptoms. RESULTS Eight patients (14%) achieved clinical resolution and 49 (86%) improved with B12 therapy. The absence of sensory dermatomal deficit, Romberg, and Babinski signs were associated with a higher complete resolution rate. Patients with MRI lesions in ≤7 segments and age less than 50 also appear to have higher rates of complete resolution. CONCLUSIONS B12 therapy is reported to stop progression and improve neurologic deficits in most patients with subacute combined degeneration. However, complete resolution only occurs in a small percentage of patients and appears to be associated with factors suggestive of less severe disease at the time of diagnosis. PMID:16970556

  19. Activation of ganglion cells in wild-type and rd1 mouse retinas with monophasic and biphasic current pulses

    NASA Astrophysics Data System (ADS)

    Jensen, Ralph J.; Rizzo, Joseph F. III

    2009-06-01

    We and other research groups are designing an electronic retinal prosthesis to provide vision for patients who are blind due to photoreceptor degeneration. In this study, we examined the effect of stimulus waveform on the amount of current needed to activate retinal ganglion cells (RGCs) when the retinal neural network is stimulated. Isolated retinas of wild-type and rd1 mice were stimulated with cathodal and anodal monophasic current pulses of 1 ms duration and symmetric biphasic current pulses (1 ms per phase) delivered through an electrode that was located subretinally. For both wild-type and rd1 mouse retinas, cathodal current pulses were least effective in activating most RGCs. The median threshold current for a cathodal current pulse was 2.0-4.4 fold higher than the median threshold current for either an anodal or a biphasic current pulse. In wild-type mouse retinas, the median threshold current for activating RGCs with anodal current pulses was 23% lower than that with biphasic current pulses. In rd1 mouse retinas, the median threshold currents for anodal and biphasic current pulses were about the same. However, the variance in thresholds of rd1 RGCs for biphasic pulse stimulation was much smaller than for anodal pulse stimulation. Thus, a symmetric biphasic current pulse may be the best stimulus for activating the greatest number of RGCs in retinas devoid of photoreceptors.

  20. Down-regulation of semaphorin 3F in rat retinal ganglion cells in response to optic nerve crush.

    PubMed

    Ko, Ji-Ae; Minamoto, Akira; Sugimoto, Yosuke; Kiuchi, Yoshiaki

    2016-07-01

    Glaucoma is characterized by degeneration of optic nerve axons and death of retinal ganglion cells (RGCs). Nerve crush and axotomy of the optic nerve are studied as models of RGC death in glaucoma and of axon regeneration. The mechanisms underlying the response of RGCs to axonal injury remain unclear, however. We have now examined the effects of optic nerve crush on the expression of members of the semaphorin family of neuronal guidance proteins in the rat retina. The expression of semaphorin 3F (Sema3F) in the retina was down-regulated at both the mRNA and protein levels at 7 days after optic nerve injury, whereas that of Sema3A, Sema3B or Sema3C remained unaffected. Immunohistofluorescence analysis and laser capture microdissection followed by reverse transcription-polymerase chain reaction analysis revealed that this loss of Sema3F expression occurred in the RGC layer of the retina. Furthermore, antibody-mediated neutralization of secreted Sema3F in retinal organ culture resulted in down-regulation of neuron-specific βIII-tubulin (Tuj-1 antigen), a marker of RGCs. Our results suggest that Sema3F may contribute to the regulation of RGC function or survival and therefore warrants further investigation as a potential mediator of neuroprotection. Copyright © 2016 John Wiley & Sons, Ltd. PMID:27309587

  1. Increased production of omega-3 fatty acids protects retinal ganglion cells after optic nerve injury in mice.

    PubMed

    Peng, Shanshan; Shi, Zhe; Su, Huanxing; So, Kwok-Fai; Cui, Qi

    2016-07-01

    Injury to the central nervous system causes progressive degeneration of injured axons, leading to loss of the neuronal bodies. Neuronal survival after injury is a prerequisite for successful regeneration of injured axons. In this study, we investigated the effects of increased production of omega-3 fatty acids and elevation of cAMP on retinal ganglion cell (RGC) survival and axonal regeneration after optic nerve (ON) crush injury in adult mice. We found that increased production of omega-3 fatty acids in mice enhanced RGC survival, but not axonal regeneration, over a period of 3 weeks after ON injury. cAMP elevation promoted RGC survival in wild type mice, but no significant difference in cell survival was seen in mice over-producing omega-3 fatty acids and receiving intravitreal injections of CPT-cAMP, suggesting that cAMP elevation protects RGCs after injury but does not potentiate the actions of the omega-3 fatty acids. The observed omega-3 fatty acid-mediated neuroprotection is likely achieved partially through ERK1/2 signaling as inhibition of this pathway by PD98059 hindered, but did not completely block, RGC protection. Our study thus enhances our current understanding of neural repair after CNS injury, including the visual system. PMID:27264241

  2. Caffeine administration prevents retinal neuroinflammation and loss of retinal ganglion cells in an animal model of glaucoma

    PubMed Central

    Madeira, Maria H.; Ortin-Martinez, Arturo; Nadal-Nícolas, Francisco; Ambrósio, António F.; Vidal-Sanz, Manuel; Agudo-Barriuso, Marta; Santiago, Ana Raquel

    2016-01-01

    Glaucoma is the second leading cause of blindness worldwide, being characterized by progressive optic nerve damage and loss of retinal ganglion cells (RGCs), accompanied by increased inflammatory response involving retinal microglial cells. The etiology of glaucoma is still unknown, and despite elevated intraocular pressure (IOP) being a major risk factor, the exact mechanisms responsible for RGC degeneration remain unknown. Caffeine, which is an antagonist of adenosine receptors, is the most widely consumed psychoactive drug in the world. Several evidences suggest that caffeine can attenuate the neuroinflammatory responses and afford protection upon central nervous system (CNS) injury. We took advantage of a well characterized animal model of glaucoma to investigate whether caffeine administration controls neuroinflammation and elicits neuroprotection. Caffeine or water were administered ad libitum and ocular hypertension (OHT) was induced by laser photocoagulation of the limbal veins in Sprague Dawley rats. Herein, we show that caffeine is able to partially decrease the IOP in ocular hypertensive animals. More importantly, we found that drinking caffeine prevented retinal microglia-mediated neuroinflammatory response and attenuated the loss of RGCs in animals with ocular hypertension (OHT). This study opens the possibility that caffeine or adenosine receptor antagonists might be a therapeutic option to manage RGC loss in glaucoma. PMID:27270337

  3. Caffeine administration prevents retinal neuroinflammation and loss of retinal ganglion cells in an animal model of glaucoma.

    PubMed

    Madeira, Maria H; Ortin-Martinez, Arturo; Nadal-Nícolas, Francisco; Ambrósio, António F; Vidal-Sanz, Manuel; Agudo-Barriuso, Marta; Santiago, Ana Raquel

    2016-01-01

    Glaucoma is the second leading cause of blindness worldwide, being characterized by progressive optic nerve damage and loss of retinal ganglion cells (RGCs), accompanied by increased inflammatory response involving retinal microglial cells. The etiology of glaucoma is still unknown, and despite elevated intraocular pressure (IOP) being a major risk factor, the exact mechanisms responsible for RGC degeneration remain unknown. Caffeine, which is an antagonist of adenosine receptors, is the most widely consumed psychoactive drug in the world. Several evidences suggest that caffeine can attenuate the neuroinflammatory responses and afford protection upon central nervous system (CNS) injury. We took advantage of a well characterized animal model of glaucoma to investigate whether caffeine administration controls neuroinflammation and elicits neuroprotection. Caffeine or water were administered ad libitum and ocular hypertension (OHT) was induced by laser photocoagulation of the limbal veins in Sprague Dawley rats. Herein, we show that caffeine is able to partially decrease the IOP in ocular hypertensive animals. More importantly, we found that drinking caffeine prevented retinal microglia-mediated neuroinflammatory response and attenuated the loss of RGCs in animals with ocular hypertension (OHT). This study opens the possibility that caffeine or adenosine receptor antagonists might be a therapeutic option to manage RGC loss in glaucoma. PMID:27270337

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

    PubMed Central

    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

  5. Macro- and microstructure of the superior cervical ganglion in dogs, cats and horses during maturation.

    PubMed

    Fioretto, Emerson Ticona; de Abreu, Rogério Navarro; Castro, Marcelo Fernandes de Souza; Guidi, Wanderley Lima; Ribeiro, Antonio Augusto Coppi Maciel

    2007-01-01

    The superior cervical ganglion (SCG) provides sympathetic input to the head and neck, its relation with mandible, submandibular glands, eyes (second and third order control) and pineal gland being demonstrated in laboratory animals. In addition, the SCG's role in some neuropathies can be clearly seen in Horner's syndrome. In spite of several studies published involving rats and mice, there is little morphological descriptive and comparative data of SCG from large mammals. Thus, we investigated the SCG's macro- and microstructural organization in medium (dogs and cats) and large animals (horses) during a very specific period of the post-natal development, namely maturation (from young to adults). The SCG of dogs, cats and horses were spindle shaped and located deeply into the bifurcation of the common carotid artery, close to the distal vagus ganglion and more related to the internal carotid artery in dogs and horses, and to the occipital artery in cats. As to macromorphometrical data, that is ganglion length, there was a 23.6% increase from young to adult dogs, a 1.8% increase from young to adult cats and finally a 34% increase from young to adult horses. Histologically, the SCG's microstructure was quite similar between young and adult animals and among the 3 species. The SCG was divided into distinct compartments (ganglion units) by capsular septa of connective tissue. Inside each ganglion unit the most prominent cellular elements were ganglion neurons, glial cells and small intensely fluorescent cells, comprising the ganglion's morphological triad. Given this morphological arrangement, that is a summation of all ganglion units, SCG from dogs, cats and horses are better characterized as a ganglion complex rather than following the classical ganglion concept. During maturation (from young to adults) there was a 32.7% increase in the SCG's connective capsule in dogs, a 25.8% increase in cats and a 33.2% increase in horses. There was an age-related increase in the

  6. Retinal Cell Degeneration in Animal Models

    PubMed Central

    Niwa, Masayuki; Aoki, Hitomi; Hirata, Akihiro; Tomita, Hiroyuki; Green, Paul G.; Hara, Akira

    2016-01-01

    The aim of this review is to provide an overview of various retinal cell degeneration models in animal induced by chemicals (N-methyl-d-aspartate- and CoCl2-induced), autoimmune (experimental autoimmune encephalomyelitis), mechanical stress (optic nerve crush-induced, light-induced) and ischemia (transient retinal ischemia-induced). The target regions, pathology and proposed mechanism of each model are described in a comparative fashion. Animal models of retinal cell degeneration provide insight into the underlying mechanisms of the disease, and will facilitate the development of novel effective therapeutic drugs to treat retinal cell damage. PMID:26784179

  7. Ion acoustic shock waves in degenerate plasmas

    SciTech Connect

    Akhtar, N.; Hussain, S.

    2011-07-15

    Korteweg de Vries Burgers equation for negative ion degenerate dissipative plasma has been derived using reductive perturbation technique. The quantum hydrodynamic model is used to study the quantum ion acoustic shock waves. The effects of different parameters on quantum ion acoustic shock waves are studied. It is found that quantum parameter, electrons Fermi temperature, temperature of positive and negative ions, mass ratio of positive to negative ions, viscosity, and density ratio have significant impact on the shock wave structure in negative ion degenerate plasma.

  8. Kinematic control of robot with degenerate wrist

    NASA Technical Reports Server (NTRS)

    Barker, L. K.; Moore, M. C.

    1984-01-01

    Kinematic resolved rate equations allow an operator with visual feedback to dynamically control a robot hand. When the robot wrist is degenerate, the computed joint angle rates exceed operational limits, and unwanted hand movements can result. The generalized matrix inverse solution can also produce unwanted responses. A method is introduced to control the robot hand in the region of the degenerate robot wrist. The method uses a coordinated movement of the first and third joints of the robot wrist to locate the second wrist joint axis for movement of the robot hand in the commanded direction. The method does not entail infinite joint angle rates.

  9. Pathogenesis of tendinopathies: inflammation or degeneration?

    PubMed Central

    Abate, Michele; Gravare-Silbernagel, Karin; Siljeholm, Carl; Di Iorio, Angelo; De Amicis, Daniele; Salini, Vincenzo; Werner, Suzanne; Paganelli, Roberto

    2009-01-01

    The intrinsic pathogenetic mechanisms of tendinopathies are largely unknown and whether inflammation or degeneration has the prominent role is still a matter of debate. Assuming that there is a continuum from physiology to pathology, overuse may be considered as the initial disease factor; in this context, microruptures of tendon fibers occur and several molecules are expressed, some of which promote the healing process, while others, including inflammatory cytokines, act as disease mediators. Neural in-growth that accompanies the neovessels explains the occurrence of pain and triggers neurogenic-mediated inflammation. It is conceivable that inflammation and degeneration are not mutually exclusive, but work together in the pathogenesis of tendinopathies. PMID:19591655

  10. CT of sarcomatous degeneration in neurofibromatosis

    SciTech Connect

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

    1983-02-01

    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.

  11. Protective Effect of Total Flavones from Hippophae rhamnoides L. against Visible Light-Induced Retinal Degeneration in Pigmented Rabbits.

    PubMed

    Wang, Yong; Huang, Fenghong; Zhao, Liang; Zhang, Di; Wang, Ou; Guo, Xiaoxuan; Lu, Feng; Yang, Xue; Ji, Baoping; Deng, Qianchun

    2016-01-13

    Sea buckthorn (Hippophae rhamnoides L.) flavones have been used as candidate functional food ingredients because of their bioactivities, such as treating cardiovascular disorders, lowering plasma cholesterol level, and regulating immune function. However, the protective effects of sea buckthorn flavones against retinal degeneration remain unclear to date. This study investigated the protective effects of total flavones from H. rhamnoides (TFH) against visible light-induced retinal damage and explored the related mechanisms in pigmented rabbits. Rabbits were treated with TFH (250 and 500 mg/kg) for 2 weeks pre-illumination and 1 week post-illumination until sacrifice. Retinal function was quantified by performing electroretinography 1 day before and 1, 3, and 7 days after light exposure (18000 lx for 2 h). Retinal degeneration was evaluated by measuring the thickness of the outer nuclear layer (ONL) and performing the TUNEL assay 7 days after light exposure. Enzyme-linked immunosorbent assay, Western blot analysis, and immunohistochemistry were used to explore the antioxidant, anti-inflammatory, and anti-apoptotic mechanisms of TFH during visible light-induced retinal degeneration. Light exposure produced a degenerative effect primarily on the ONL, inner nuclear layer (INL), and ganglion cell layer (GCL). TFH significantly attenuated the destruction of electroretinograms caused by light damage, maintained ONL thickness, and decreased the number of TUNEL-positive cells in the INL and GCL. TFH ameliorated the retinal oxidative stress (GSH-Px, CAT, T-AOC, and MDA), inflammation (IL-1β and IL-6), angiogenesis (VEGF), and apoptosis (Bax, Bcl2, and caspase-3) induced by light exposure. Therefore, TFH exhibited protective effects against light-induced retinal degeneration by increasing the antioxidant defense mechanisms, suppressing pro-inflammatory and angiogenic cytokines, and inhibiting retinal cell apoptosis. PMID:26653970

  12. Hyperactivity of ON-type retinal ganglion cells in streptozotocin-induced diabetic mice.

    PubMed

    Yu, Jun; Wang, Lu; Weng, Shi-Jun; Yang, Xiong-Li; Zhang, Dao-Qi; Zhong, Yong-Mei

    2013-01-01

    Impairment of visual function has been detected in the early stage of diabetes but the underlying neural mechanisms involved are largely unknown. Morphological and functional alterations of retinal ganglion cells, the final output neurons of the vertebrate retina, are thought to be the major cause of visual defects in diabetes but direct evidence to support this notion is limited. In this study we investigated functional changes of retinal ganglion cells in a type 1-like diabetic mouse model. Our results demonstrated that the spontaneous spiking activity of ON-type retinal ganglion cells was increased in streptozotocin-diabetic mice after 3 to 4 months of diabetes. At this stage of diabetes, no apoptotic signals or cell loss were detected in the ganglion cell layer of the retina, suggesting that the functional alterations in ganglion cells occur prior to massive ganglion cell apoptosis. Furthermore, we found that the increased activity of ON-type ganglion cells was mainly a result of reduced inhibitory signaling to the cells in diabetes. This novel mechanism provides insight into how visual function is impaired in diabetic retinopathy. PMID:24069457

  13. Hyperactivity of ON-Type Retinal Ganglion Cells in Streptozotocin-Induced Diabetic Mice

    PubMed Central

    Yu, Jun; Wang, Lu; Weng, Shi-Jun; Yang, Xiong-Li; Zhang, Dao-Qi; Zhong, Yong-Mei

    2013-01-01

    Impairment of visual function has been detected in the early stage of diabetes but the underlying neural mechanisms involved are largely unknown. Morphological and functional alterations of retinal ganglion cells, the final output neurons of the vertebrate retina, are thought to be the major cause of visual defects in diabetes but direct evidence to support this notion is limited. In this study we investigated functional changes of retinal ganglion cells in a type 1-like diabetic mouse model. Our results demonstrated that the spontaneous spiking activity of ON-type retinal ganglion cells was increased in streptozotocin-diabetic mice after 3 to 4 months of diabetes. At this stage of diabetes, no apoptotic signals or cell loss were detected in the ganglion cell layer of the retina, suggesting that the functional alterations in ganglion cells occur prior to massive ganglion cell apoptosis. Furthermore, we found that the increased activity of ON-type ganglion cells was mainly a result of reduced inhibitory signaling to the cells in diabetes. This novel mechanism provides insight into how visual function is impaired in diabetic retinopathy. PMID:24069457

  14. Short-wavelength cone-opponent retinal ganglion cells in mammals

    PubMed Central

    MARSHAK, DAVID W.; MILLS, STEPHEN L.

    2014-01-01

    In all of the mammalian species studied to date, the short-wavelength-sensitive (S) cones and the S-cone bipolar cells that receive their input are very similar, but the retinal ganglion cells that receive synapses from the S-cone bipolar cells appear to be quite different. Here, we review the literature on mammalian retinal ganglion cells that respond selectively to stimulation of S-cones and respond with opposite polarity to longer wavelength stimuli. There are at least three basic mechanisms to generate these color-opponent responses, including: (1) opponency is generated in the outer plexiform layer by horizontal cells and is conveyed to the ganglion cells via S-cone bipolar cells, (2) inputs from bipolar cells with different cone inputs and opposite response polarity converge directly on the ganglion cells, and (3) inputs from S-cone bipolar cells are inverted by S-cone amacrine cells. These are not mutually exclusive; some mammalian ganglion cells that respond selectively to S-cone stimulation seem to utilize at least two of them. Based on these findings, we suggest that the small bistratified ganglion cells described in primates are not the ancestral type, as proposed previously. Instead, the known types of ganglion cells in this pathway evolved from monostratified ancestral types and became bistratified in some mammalian lineages. PMID:24759445

  15. Short-wavelength cone-opponent retinal ganglion cells in mammals.

    PubMed

    Marshak, David W; Mills, Stephen L

    2014-03-01

    In all of the mammalian species studied to date, the short-wavelength-sensitive (S) cones and the S-cone bipolar cells that receive their input are very similar, but the retinal ganglion cells that receive synapses from the S-cone bipolar cells appear to be quite different. Here, we review the literature on mammalian retinal ganglion cells that respond selectively to stimulation of S-cones and respond with opposite polarity to longer wavelength stimuli. There are at least three basic mechanisms to generate these color-opponent responses, including: (1) opponency is generated in the outer plexiform layer by horizontal cells and is conveyed to the ganglion cells via S-cone bipolar cells, (2) inputs from bipolar cells with different cone inputs and opposite response polarity converge directly on the ganglion cells, and (3) inputs from S-cone bipolar cells are inverted by S-cone amacrine cells. These are not mutually exclusive; some mammalian ganglion cells that respond selectively to S-cone stimulation seem to utilize at least two of them. Based on these findings, we suggest that the small bistratified ganglion cells described in primates are not the ancestral type, as proposed previously. Instead, the known types of ganglion cells in this pathway evolved from monostratified ancestral types and became bistratified in some mammalian lineages. PMID:24759445

  16. A Dopamine- and Protein Kinase A-Dependent Mechanism for Network Adaptation in Retinal Ganglion Cells

    PubMed Central

    Vaquero, C. F.; Pignatelli, A.; Partida, G. J.; Ishida, A. T.

    2011-01-01

    Vertebrates can detect light intensity changes in vastly different photic environments, in part, because post-receptoral neurons undergo “network adaptation”. Previous data implicated dopaminergic, cAMP-dependent inhibition of retinal ganglion cells in this process, yet left unclear how this occurs, and whether this occurs in darkness versus light. To test for light- and dopamine-dependent changes in ganglion cell cAMP levels in situ, we immunostained dark- and light-adapted retinas with anti-cAMP antisera, in the presence and absence of various dopamine receptor ligands. To test for direct effects of dopamine receptor ligands and membrane-permeable protein kinase ligands on ganglion cell excitability, we recorded spikes from isolated ganglion cells in perforated-patch whole-cell mode, before and during application of these agents by microperfusion. Our immunostainings show that light, endogenous dopamine, and exogenous dopamine elevate ganglion cell cAMP levels in situ by activating D1-type dopamine receptors. Our spike recordings show that D1-type agonists and 8-bromo cAMP reduce spike frequency and curtail sustained spike firing, and that these effects entail protein kinase A activation. These effects resemble those of background light on ganglion cell responses to light flashes. Network adaptation could thus be produced, to some extent, by dopaminergic modulation of ganglion cell spike generation, a mechanism distinct from modulation of transmitter release onto ganglion cells or of transmitter-gated currents in ganglion cells. Combining these observations, with results obtained in studies of photoreceptor, bipolar, and horizontal cells, indicates that all three layers of neurons in the retina are equipped with mechanisms for adaptation to ambient light. PMID:11606650

  17. Spontaneous Discharge Patterns in Cochlear Spiral Ganglion Cells Prior to the Onset of Hearing in Cats

    PubMed Central

    Jones, Timothy A.; Leake, Patricia A.; Snyder, Russell L.; Stakhovskaya, Olga; Bonham, Ben

    2008-01-01

    Spontaneous neural activity has been recorded in the auditory nerve of cats as early as 2 days postnatal (P2 ), yet individual auditory neurons do not respond to ambient sound levels below 90–100 dB SPL until about P10. Significant refinement of the central projections from the spiral ganglion to the cochlear nucleus occurs during this neonatal period. This refinement may be dependent on peripheral spontaneous discharge activity. We recorded from single spiral ganglion cells in kittens aged P3 to P9. The spiral ganglion was accessed via the round window through the spiral lamina. A total of 112 ganglion cells were isolated for study in 9 animals. Spike rates in neonates were very low, ranging from 0.06 to 56 sp/s with a mean of 3.09 +/− 8.24 sp/s. Ganglion cells in neonatal kittens exhibited remarkable repetitive spontaneous bursting discharge patterns. The unusual patterns were evident in the large mean interval coefficient of variation (CVi = 2.9 +/−1.6) and burst index of 5.2 +/− 3.5 across ganglion cells. Spontaneous bursting patterns in these neonatal mammals were similar to those reported for cochlear ganglion cells of the embryonic chicken suggesting this may be a general phenomenon that is common across animal classes. Rhythmic spontaneous discharge of retinal ganglion cells has been shown to be important in the development of central retinotopic projections and normal binocular vision (Shatz, 1996, Proc Natl Acad Sci 93). Bursting rhythms in cochlear ganglion cells may play a similar role in the auditory system during pre-hearing periods. PMID:17686914

  18. Driving and Age-Related Macular Degeneration

    ERIC Educational Resources Information Center

    Owsley, Cynthia; McGwin, Gerald, Jr.

    2008-01-01

    This article reviews the research literature on driving and age-related macular degeneration, which is motivated by the link between driving and the quality of life of older adults and their increased collision rate. It addresses the risk of crashes, driving performance, driving difficulty, self-regulation, and interventions to enhance, safety,…

  19. Depression in Age-Related Macular Degeneration

    ERIC Educational Resources Information Center

    Casten, Robin; Rovner, Barry

    2008-01-01

    Age-related macular degeneration (AMD) is a major cause of disability in the elderly, substantially degrades the quality of their lives, and is a risk factor for depression. Rates of depression in AMD are substantially greater than those found in the general population of older people, and are on par with those of other chronic and disabling…

  20. A family of degenerate Lie algebras

    NASA Astrophysics Data System (ADS)

    Cruz, I.

    1999-08-01

    We show that almost all the real Lie algebras with only zero- and two-dimensional coadjoint orbits are degenerate in both the smooth and analytic category. The only exceptions are the already known cases (studied for example by Dufour and Weinstein).

  1. Spectroscopic observations of cool degenerate star candidates

    NASA Technical Reports Server (NTRS)

    Hintzen, P.

    1986-01-01

    Spectroscopic observations are reported for 23 Luyten Half-Second degenerate star candidates and for 13 Luyten-Palomar common proper-motion pairs containing possible degenerate star components. Twenty-five degenerate stars are identified, 20 of which lack previous spectroscopy. Most of these stars are cool - Luyten color class g or later. One star, LP 77-57, shows broad continuum depressions similar to those in LHS 1126, which Liebert and Dahn attributed to pressure-shifted C2. A second degenerate star, LHS 290, exhibits apparent strong Swan bands which are blueshifted about 75 A. Further observations, including polarimetry and photometry, are required to appraise the spectroscopic peculiarities of these stars. Finally, five cool, sharp-lined DA white dwarfs have been observed to detect lines of metals and to determine line strengths. None of these DAs show signs of Mg b or the G band, and four show no evidence of Ca II K. The attempt to detect Ca MI in the fifth star, G199-71, was inconclusive.

  2. Driving and Age-Related Macular Degeneration

    PubMed Central

    Owsley, Cynthia; McGwin, Gerald

    2009-01-01

    This article reviews the research literature on driving and age-related macular degeneration, which is motivated by the link between driving and the quality of life of older adults and their increased collision rate. It addresses the risk of crashes, driving performance, driving difficulty, self-regulation, and interventions to enhance, safety, and considers directions for future research. PMID:20046818

  3. Tenascin-C and human tendon degeneration.

    PubMed Central

    Riley, G. P.; Harrall, R. L.; Cawston, T. E.; Hazleman, B. L.; Mackie, E. J.

    1996-01-01

    We investigated the distribution of tenascin in supraspinatus tendons to determine whether an alteration in tenascin expression was associated with human tendon degeneration. Tenascin was present in all of the tendons studied, although with two distinct patterns of expression. First, tenascin was associated with organized, fibrous regions of the tendon matrix that were typical of the normal tendon structure. This distribution is consistent with a role for tenascin in collagen fibril organization, perhaps maintaining the interface between fibrils and adjacent structures. Second, although tenascin was generally absent from poorly organized matrix in degenerate tendons, it was strongly associated with some rounded cells in disorganized fibrocartilaginous regions that were more abundant in pathological specimens. Tenascin was also found around infiltrating blood vessels, with more intense staining associated with a mononuclear cell infiltrate. Western blotting of tendon extracts showed differences in tenascin isoform expression, with only the small (200-kd) tenascin isoform found in normal tendons. Degenerate tendons also expressed the 300-kd isoform, consistent with a role for the larger tenascin isoform in tendon disease, potentially stimulating tenocyte proliferation, cell rounding, and fibrocartilaginous change. Proteolytic fragments of tenascin were detected but only in ruptured tendons, an indication of matrix remodeling in degenerate tendons, with fragment sizes consistent with the activity of matrix metalloproteinase enzymes. Images Figure 1 Figure 2 Figure 3 Figure 4 PMID:8780397

  4. GABAergic and glycinergic pathways to goldfish retinal ganglion cells: an ultrastructural double label study

    SciTech Connect

    Muller, J.F.

    1987-01-01

    An ultrastructural double label has been employed to compare GABAergic and glycinergic systems in the inner plexiform layer (IPL) of the goldfish retina. Electron microscope autoradiography of /sup 3/H-GABA and /sup 3/H-glycine uptake was combined with retrograde HRP-labeling of ganglion cells. When surveyed for distribution, GABAergic and glycinergic synapses were found onto labeled ganglion cells throughout the IPL. This reinforces previous physiological work that described GABAergic and glycinergic influences on a variety of ganglion cells in goldfish and carp; These physiological effects often reflect direct inputs.

  5. Recent advances in basic research on the trigeminal ganglion.

    PubMed

    Goto, Tetsuya; Oh, Seog Bae; Takeda, Mamoru; Shinoda, Masamichi; Sato, Tadasu; Gunjikake, Kaori K; Iwata, Koichi

    2016-09-01

    Peripheral tissue inflammation can alter the properties of somatic sensory pathways, causing behavioral hypersensitivity and resulting in increased responses to pain caused by noxious stimulation (hyperalgesia) and normally innocuous stimulation (allodynia). These hypersensitivities for nociception are caused by changes in the excitability of trigeminal ganglion (TG) neurons. These changes alter sensory information processing in the neurons in the medullary trigeminal nucleus of caudalis. Increasing information is becoming available regarding trigeminal neuron-neuron/neuron-satellite glial cells (SGCs) communication. The activation of intraganglionic communication plays an important role in the creation and maintenance of trigeminal pathological pain. Therefore, in this review, we focus on the recent findings for sensory functions and pharmacological modulation of TG neurons and SGCs under normal and pathological conditions, and we discuss potential therapeutic targets in glia-neuronal interactions for the prevention of trigeminal neuropathic and inflammatory pain. PMID:27023716

  6. Bulk electroporation of retinal ganglion cells in live Xenopus tadpoles.

    PubMed

    Ruthazer, Edward S; Schohl, Anne; Schwartz, Neil; Tavakoli, Aydin; Tremblay, Marc; Cline, Hollis T

    2013-08-01

    Individual neurons in the developing nervous system of Xenopus laevis can be visualized by the targeted delivery of a fluorophore. The fluorophore can be delivered as a fluorescent dye or DNA that encodes a fluorescent protein. Local iontophoresis is a method that works well for transfer of fluorescent dye to retinal ganglion cells (RGCs) in the eye, but it does not give a high yield for delivery of DNA. This is largely because the degree of pigmentation of the eyes, even in albino strains, makes it difficult to visualize RGC somata during pipette positioning. Bulk retinal electroporation is a better approach for delivery of plasmid DNA to RGC. The method described here works best in tadpoles older than stage 42. PMID:23906915

  7. Mouse models of retinal ganglion cell death and glaucoma

    PubMed Central

    McKinnon, Stuart J.; Schlamp, Cassandra L.; Nickells, Robert W.

    2011-01-01

    Once considered too difficult to use for glaucoma studies, mice are now becoming a powerful tool in the research of the molecular and pathological events associated with this disease. Often adapting technologies first developed in rats, ganglion cell death in mice can be induced using acute models and chronic models of experimental glaucoma. Similarly, elevated IOP has been reported in transgenic animals carrying defects in targeted genes. Also, one group of mice, from the DBA/2 line of inbred animals, develops a spontaneous optic neuropathy with many features of human glaucoma that is associated with IOP elevation caused by an anterior chamber pigmentary disease. The advent of mice for glaucoma research is already having a significant impact on our understanding of this disease, principally because of the access to genetic manipulation technology and genetics already well established for these animals. PMID:19105954

  8. In Vitro Functional Assessment of Adult Spiral Ganglion Neurons (SGNs).

    PubMed

    Lee, Jeong Han; Sihn, Choongryoul; Wang, Wanging; Flores, Cristina Maria Perez; Yamoah, Ebenezer N

    2016-01-01

    Spiral ganglion neurons (SGNs) faithfully encode acoustic waves from hair cells to the cochlear nucleus (CN) using voltage-dependent ion channels. A sizable portion of our knowledge on SGN functions have been derived from pre-hearing neurons. In post-hearing SGNs, the mechanisms of how they encode the massive sound information without delay and precisely are largely unknown. Mature SGNs are housed in the central bony labyrinth of the cochlea, protected by a well-insulated myelin sheath, making it a technical feat to isolate viable neurons for rigorous functional electrophysiology. Recently, we have overcome the previous intractable hindrance in SGN functional analyses. We provide a step-by-step user-friendly protocol with practical applications, including patch-clamp recordings and imaging by using cultured SGNs. PMID:27259946

  9. Electronic neuron within a ganglion of a leech (Hirudo medicinalis)

    NASA Astrophysics Data System (ADS)

    Aliaga, J.; Busca, N.; Minces, V.; Mindlin, G. B.; Pando, B.; Salles, A.; Sczcupak, L.

    2003-06-01

    We report the construction of an electronic device that models and replaces a neuron in a midbody ganglion of the leech Hirudo medicinalis. In order to test the behavior of our device, we used a well-characterized synaptic interaction between the mechanosensory, sensitive to pressure, (P) cell and the anteropagoda (because of the action potential shape) (AP) neuron. We alternatively stimulated a P neuron and our device connected to the AP neuron, and studied the response of the latter. The number and timing of the AP spikes were the same when the electronic parameters were properly adjusted. Moreover, after changes in the depolarization of the AP cell, the responses under the stimulation of both the biological neuron and the electronic device vary in a similar manner.

  10. Spectrum of MRI features of ganglion and synovial cysts.

    PubMed

    Neto, Nelson; Nunnes, Pedro

    2016-04-01

    Ganglion and synovial cysts occur mainly, but not necessarily, in association with osteoarthritis. Presentation varies widely, ranging from small, incidentally detected, asymptomatic lesions to giant ones that might be the source of symptoms, either due to their compressive effect on adjacent structures or due to complications, such as rupture. On magnetic resonance imaging they are typically presented as smooth, well-circumscribed, thin-walled, unilocular, and homogeneously T2-hyperintense lesions. An identifiable thin stalk communicating to the joint space is not infrequent. Nevertheless, depending on their age, anatomic location, and eventual complication, they might have many distinct appearances, including septae and internal debris, which the radiologist must be familiar with in order to accurately differentiate them from worrisome cystic-like lesions. With regard to this diversity, some illustrative cases are presented. PMID:26911967

  11. Ganglion cysts of the wrist: pathophysiology, clinical picture, and management.

    PubMed

    Gude, Warren; Morelli, Vincent

    2008-12-01

    This article reviews what is known about ganglion cyst formation, natural history (50% of cysts will spontaneously resolve), diagnosis, and management of this common malady. Although the exact mechanism of cyst formation is unknown, most current theories hold that extra-articular mucin "droplets" coalesce to form the main body of the tumor. Only subsequently are the "cyst wall" and pedicle (connecting the cyst to a nearby synovial joint) formed. Treatment options include watchful waiting, nonoperative aspiration/injection, and surgical removal. Although treatment is often unnecessary, many patients seeking consultation desire some form of definitive treatment. Cyst aspiration/injection is fraught with a high incidence of recurrence. Surgery generally results in lower rates of recurrence, but a higher incidence of complications. All current treatment options are suboptimal. PMID:19468907

  12. Purinergic signaling in retinal degeneration and regeneration.

    PubMed

    Reichenbach, Andreas; Bringmann, Andreas

    2016-05-01

    Purinergic signaling is centrally involved in mediating the degeneration of the injured and diseased retina, the induction of retinal gliosis, and the protection of the retinal tissue from degeneration. Dysregulated calcium signaling triggered by overactivation of P2X7 receptors is a crucial step in the induction of neuronal and microvascular cell death under pathogenic conditions like ischemia-hypoxia, elevated intraocular pressure, and diabetes, respectively. Overactivation of P2X7 plays also a pathogenic role in inherited and age-related photoreceptor cell death and in the age-related dysfunction and degeneration of the retinal pigment epithelium. Gliosis of micro- and macroglial cells, which is induced and/or modulated by purinergic signaling and associated with an impaired homeostatic support to neurons, and the ATP-mediated propagation of retinal gliosis from a focal injury into the surrounding noninjured tissue are involved in inducing secondary cell death in the retina. On the other hand, alterations in the glial metabolism of extracellular nucleotides, resulting in a decreased level of ATP and an increased level of adenosine, may be neuroprotective in the diseased retina. Purinergic signals stimulate the proliferation of retinal glial cells which contributes to glial scarring which has protective effects on retinal degeneration and adverse effects on retinal regeneration. Pharmacological modulation of purinergic receptors, e.g., inhibition of P2X and activation of adenosine receptors, may have clinical importance for the prevention of photoreceptor, neuronal, and microvascular cell death in diabetic retinopathy, retinitis pigmentosa, age-related macular degeneration, and glaucoma, respectively, for the clearance of retinal edema, and the inhibition of dysregulated cell proliferation in proliferative retinopathies. This article is part of a Special Issue entitled 'Purines in Neurodegeneration and Neuroregeneration'. PMID:25998275

  13. Ultrasound-guided stellate ganglion block: safety and efficacy.

    PubMed

    Narouze, Samer

    2014-06-01

    Cervical sympathetic and stellate ganglion blocks (SGB) provide a valuable diagnostic and therapeutic benefit to sympathetically maintained pain syndromes in the head, neck, and upper extremity. With the ongoing efforts to improve the safety of the procedure, the techniques for SGB have evolved over time, from the use of the standard blind technique, to fluoroscopy, and recently to the ultrasound (US)-guided approach. Over the past few years, there has been a growing interest in the ultrasound-guided technique and the many advantages that it might offer. Fluoroscopy is a reliable method for identifying bony surfaces, which facilitates identifying the C6 and C7 transverse processes. However, this is only a surrogate marker for the cervical sympathetic trunk. The ideal placement of the needle tip should be anterolateral to the longus colli muscle, deep to the prevertebral fascia (to avoid spread along the carotid sheath) but superficial to the fascia investing the longus colli muscle (to avoid injecting into the muscle substance). Identifying the correct fascial plane can be achieved with ultrasound guidance, thus facilitating the caudal spread of the injectate to reach the stellate ganglion at C7-T1 level, even if the needle is placed at C6 level. This allows for a more effective and precise sympathetic block with the use of a small injectate volume. Ultrasound-guided SGB may also improve the safety of the procedure by direct visualization of vascular structures (inferior thyroidal, cervical, vertebral, and carotid arteries) and soft tissue structures (thyroid, esophagus, and nerve roots). Accordingly, the risk of vascular and soft tissue injury may be minimized. PMID:24760493

  14. Effect of stellate ganglion block on laryngopharyngeal reflux disease

    PubMed Central

    Chun, Hye Jung; Lee, Mi Soon; Ahn, Ki Ryang; Kim, Chun Sook; Kang, Kyu Sik; Yoo, Sie Hyeon; Chung, Jin Hun; Kim, Nan-Seol; Seo, Yong Han; Gong, Hyung Youn; Lee, Yong Man

    2013-01-01

    Background Laryngopharyngeal reflux (LPR) disease has many symptoms such as globus pharyngeus, excessive throat clearing and hoarseness. The aim of this study was to investigate the effect of stellate ganglion block (SGB) in addition to proton pump inhibitors (PPI) on LPR. Methods Fifty patients complaining of more than 3 typical LPR symptoms for over 3 months were enrolled in the study. The P group took PPI for 8 weeks. The SP group took PPI and interwent a series of 8 SGB procedure once a week during the period of treatment. The blocks were performed one at a time unilaterally on the right and left stellate ganglions by injecting 1% mepivacaine 6 ml. We evaluated the reflux symptom index (RSI) before treatment and following 4 weeks and 8 weeks of treatment in both groups. Results After 4 weeks of treatment, the RSI of the P group decreased, but not significantly, to 16.6 ± 6.8 compared with the baseline value of 19.2 ± 2.7 (P = 0.093), whereas the RSI of the SP group decreased significantly to 9.8 ± 3.3 compared with the baseline value of 19.0 ± 4.7 (P = 0.000). After 8 weeks of treatment, the RSI of the P group decreased significantly to 13.7 ± 6.7 (P = 0.001) and the RSI of the SP group also decreased significantly to 7.7 ± 3.4 (P = 0.000). There were significant differences in the RSI between the two groups after 4 weeks (P = 0.000) and 8 weeks (P = 0.001) of treatment. Conclusions The symptoms of LPR improved earlier when PPI therapy was combined with SGB compared with PPI therapy alone. PMID:23741567

  15. A Novel Type of Complex Ganglion Cell in Rabbit Retina

    PubMed Central

    Sivyer, Benjamin; Venkataramani, Sowmya; Taylor, W. Rowland; Vaney, David I.

    2012-01-01

    The 15–20 physiological types of retinal ganglion cells (RGCs) can be grouped according to whether they fire to increased illumination in the receptive-field center (ON cells), decreased illumination (OFF cells), or both (ON-OFF cells). The diversity of RGCs has been best described in the rabbit retina, which has three types of ON-OFF RGCs with complex receptive-field properties: the ON-OFF direction-selective ganglion cells (DSGCs), the local edge detectors, and the uniformity detectors. Here we describe a novel type of bistratified ON-OFF RGC that has not been described in either physiological or morphological studies of rabbit RGCs. These cells stratify in the ON and OFF sublaminae of the inner plexiform layer, branching at about 30% and 60% depth, between the ON and OFF arbors of the bistratified DSGCs. Similar to the ON-OFF DSGCs, these cells respond with transient firing to both bright and dark spots flashed in the receptive field but, unlike the DSGCs, they show no directional preference for moving stimuli. We have termed these cells “transient ON-OFF” RGCs. Area-response measurements show that both the ON and the OFF spike responses have an antagonistic receptive-field organization, but with different spatial extents. Voltage-clamp recordings reveal transient excitatory inputs at light ON and light OFF; this excitation is strongly suppressed by surround stimulation, which also elicits direct inhibitory inputs to the cells at light ON and light OFF. Thus the receptive-field organization is mediated both within the presynaptic circuitry and by direct feed-forward inhibition. PMID:21800303

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

    PubMed Central

    Ghai, Anju; Kaushik, Teshi; Kundu, Zile Singh; Wadhera, Sarthak; Wadhera, Raman

    2016-01-01

    Background: Ultrasound imaging is an ideal tool for stellate ganglion block (SGB) due to clarity, portability, lack of radiation, and low cost. Ultrasound guided anterior approach requires the application of pressure to the anterior neck and is associated with more risk of injury to inferior thyroid artery, vertebral artery, and esophagus. The lateral approach does not interfere with nerve or vascular structures. Blockade at the C6 vertebral level results in more successful sympathetic blockade of the head and neck with less sympathetic blockade of the upper extremity compared to sympathetic blockade at C7 vertebral level, which produces successful sympathetic blockade of upper extremity. This is helpful in patients of complex regional pain syndrome of the upper limb. Hence, we conducted a study using the lateral approach at C7 level. Materials and Methods: Ultrasound guided SGBs using lateral in-plane technique at C7 level were given in 20 patients suffering from chronic pain patients of upper extremity, head, and neck using 4 ml of 0.25% bupivacaine and 1 ml of 40 mg triamcinolone. The patients were assessed for a numeric pain intensity score (NPIS), the rise in axillary temperature, the range of motion of joints of upper extremity, and resolution of edema at various time intervals up to 3 months. Results: NPIS showed a statistically significant decrease from baseline at 30 min, which was sustained till 3rd month. The rise in axillary temperature after the block was statistically significant, which was sustained till 2nd week. The edema score decreased significantly at all-time intervals (P ≤ 0.001). The restriction of motion in all joints of upper limb decreased from 13 to 3 patients. Conclusion: There is a significant variation in the anatomy of stellate ganglion at the level of C6 and C7. Ultrasound guided lateral approach increases the efficacy of SGB by deposition of drug subfascially with real-time imaging. PMID:27051366

  17. Adaptation and dynamics of cat retinal ganglion cells

    PubMed Central

    Enroth-Cugell, Christina; Shapley, R. M.

    1973-01-01

    1. The impulse/quantum (I/Q) ratio was measured as a function of background illumination for rod-dominated, pure central, linear square-wave responses of retinal ganglion cells in the cat. 2. The I/Q ratio was constant at low backgrounds (dark adapted state) and inversely proportional to the 0·9 power of the background at high backgrounds (the light adapted state). There was an abrupt transition from the dark-adapted state to the light-adapted state. 3. It was possible to define the adaptation level at a particular background as the ratio (I/Q ratio at that background)/(dark adapted I/Q ratio). 4. The time course of the square-wave response was correlated with the adaptation level. The response was sustained in the dark-adapted state, partially transient at the transition level, and progressively more transient the lower the impulse/quantum ratio of the ganglion cell became. This was true both for on-centre and off-centre cells. 5. The frequency response of the central response mechanism at different adaptation levels was measured. It was a low-pass characteristic in the dark-adapted state and became progressively more of a bandpass characteristic as the cell became more light-adapted. 6. The rapidity of onset of adaptation was measured with a time-varying adapting light. The impulse/quantum ratio is reset within 100 msec of the onset of the conditioning light, and is kept at the new value throughout the time the conditioning light is on. 7. These results can be explained by a nonlinear feedback model. In the model, it is postulated that the exponential function of the horizontal cell potential controls transmission from rods to bipolars. This model has an abrupt transition from dark- to light-adapted states, and its response dynamics are correlated with adaptation level. PMID:4747229

  18. Melanopsin, Photosensitive Ganglion Cells, and Seasonal Affective Disorder

    PubMed Central

    Roecklein, Kathryn A.; Wong, Patricia M.; Miller, Megan A.; Donofry, Shannon D.; Kamarck, Marissa L.; Brainard, George C.

    2013-01-01

    ROECKLEIN, K.A., WONG, P.M., MILLER, M.A., DONOFRY, S.D., KAMARCK, M.L., BRAINARD, G.C. Melanopsin, Photosensitive Ganglion Cells, and Seasonal Affective Disorder…NEUROSCI BIOBEHAV REV x(x) XXX-XXX, 2012. In two recent reports, melanopsin gene variations were associated with seasonal affective disorder (SAD), and in changes in the timing of sleep and activity in healthy individuals. New studies have deepened our understanding of the retinohypothalamic tract, which translates environmental light received by the retina into neural signals sent to a set of nonvisual nuclei in the brain that are responsible for functions other than sight including circadian, neuroendocrine and neurobehavioral regulation. Because this pathway mediates seasonal changes in physiology, behavior, and mood, individual variations in the pathway may explain why approximately 1–2% of the North American population develops mood disorders with a seasonal pattern (i.e., Major Depressive and Bipolar Disorders with a seasonal pattern, also known as seasonal affective disorder/SAD). Components of depression including mood changes, sleep patterns, appetite, and cognitive performance can be affected by the biological and behavioral responses to light. Specifically, variations in the gene sequence for the retinal photopigment, melanopsin, may be responsible for significant increased risk for mood disorders with a seasonal pattern, and may do so by leading to changes in activity and sleep timing in winter. The retinal sensitivity of SAD is hypothesized to be decreased compared to controls, and that further decrements in winter light levels may combine to trigger depression in winter. Here we outline steps for new research to address the possible role of melanopsin in seasonal affective disorder including chromatic pupillometry designed to measure the sensitivity of melanopsin containing retinal ganglion cells. PMID:23286902

  19. Sphenopalatine ganglion electrical nerve stimulation implant for intractable facial pain.

    PubMed

    Elahi, Foad; Reddy, Chandan G

    2015-01-01

    Persistent idiopathic facial pain can be extremely difficult and significantly challenging to manage for the patient and the clinician. Pharmacological treatment of these painful conditions is not always successful. It has been suggested that the autonomic reflex plays an important role in the pathophysiology of headaches and facial neuralgia. The key structure in the expression of cranial autonomic symptoms is the sphenopalatine ganglion (SPG), also known as the pterygopalatine ganglion. The role of the SPG in the pathophysiology of headaches and facial pain has become clearer in the past decade. In this case report, we describe a 30 year-old woman with insidious onset of right facial pain. She was suffering from daily pain for more than 9 years prior to her visit at the pain clinic. Her pain was constant with episodic aggravation without a predisposing trigger factor. The patient was evaluated by multiple different specialties and tried multimodal therapy, which included antiepileptic medications, with minimal pain relief. A SPG block using short-acting local anesthetic provided significant temporary pain relief. The second and third attempt of SPG block using different local anesthetic medications demonstrated the same responses. After a thorough psychological assessment and ruling out the presence of a correctable cause for the pain, we decided to proceed with SPG electrical neuromodulation. The patient reported significant pain relief during the electrical nerve stimulation trial. The patient underwent a permanent implant of the neurostimulation electrode in the SPG region. The patient was successfully taken off opioid medication and her pain was dramatically responsive during a 6 month follow-up visit. In this article we describe the SPG nerve stimulation and the technical aspect of pterygopalatine fossa electrode placement. The pterygoplatine fossa is an easily accessible location. This case report will be encouraging for physicians treating intractable

  20. Hydrostatic Pressure Does Not Cause Detectable Changes in Survival of Human Retinal Ganglion Cells

    PubMed Central

    Osborne, Andrew; Aldarwesh, Amal; Rhodes, Jeremy D.; Broadway, David C.; Everitt, Claire; Sanderson, Julie

    2015-01-01

    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 (10-100mmHg) was achieved using mass flow controllers. Human organotypic retinal cultures (HORCs) from donor eyes (<24h 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 (60mmHg) or fluctuating (10-100mmHg; 1 cycle/min) pressure for 24 or 48h 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 24h. p38 and JNK phosphorylation remained unchanged in HORCs exposed to fluctuating pressure (10-100mmHg; 1 cycle/min) for 15, 30, 60 and 90min durations, whereas OGD (3h) increased activation of p38 and JNK, remaining elevated for 90min 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. PMID:25635827

  1. CELASTROL SUPPORTS SURVIVAL OF RETINAL GANGLION CELLS INJURED BY OPTIC NERVE CRUSH

    PubMed Central

    Kyung, Haksu; Kwong, Jacky M. K.; Bekerman, Vlad; Gu, Lei; Yadegari, Daniel; Caprioli, Joseph; Piri, Natik

    2015-01-01

    The present study evaluates the effect of celastrol on the survival of retinal ganglion cells (RGCs) injured by optic nerve crush (ONC). Celastrol, a quinine methide triterpene extracted from the perennial vine Tripterygium wilfordii (Celastraceae), has been identified as a potential neuroprotective candidate in a comprehensive drug screen against various neurodegenerative diseases. Two weeks after ONC, the average density of remaining RGCs in retinas of animals treated with daily intraperitoneal (i.p.) injections of celastrol (1 mg/kg) was approximately 1332 cells/mm2, or 40.8% of that of the Celastrol/Control group. In retinas of the Vehicle/ONC group about 381 RGCs/mm2 were counted, which is 9.6% of the total number of RGCs in the DMSO/Control group. This corresponds to approximately a 250% increase in RGC survival mediated by celastrol treatment compared to control. Furthermore, the average RGC number in retinas of ONC animals treated with a single intravitreal injection of 1 mg/kg or 5 mg/kg of celastrol was increased by approximately 80% (760 RGCs/ mm2) and 78% (753 RGCs/mm2), respectively, compared to controls (422 cells/mm2). Injection of 0.2 mg/kg of celastrol had no significant effect on cell survival compared to DMSO-injected controls, with the average number of RGCs being 514 cells/mm2 in celastrol-treated animals versus 422 cells/mm2 in controls. The expression levels of Hsp70, Hsf1, Hsf2, HO-1 and TNF-alpha in the retina were analyzed to evaluate the roles of these proteins in the celastrol-mediated protection of injured RGCs. No statistically significant change in HO-1, Hsf1 and Hsp70 levels was seen in animals with ONC. An approximately 2 fold increase in Hsf2 level was observed in celastrol-treated animals with or without injury. Hsf2 level was also increased 1.8 fold in DMSO-treated animals with ONC injury compared to DMSO-treated animals with no injury suggesting that Hsf2 induction has an injury-induced component. Expression of TNF-alpha in

  2. Case Report: Intraneural Intracanalicular Ganglion Cyst of the Hypoglossal Nerve Treated by Extradural Transcondylar Approach

    PubMed Central

    Bilgin-Freiert, Arzu; Fugleholm, Kåre; Poulsgaard, Lars

    2015-01-01

    We report a case of an intraneural ganglion cyst of the hypoglossal canal. The patient presented with unilateral hypoglossal nerve palsy, and magnetic resonance imaging showed a small lesion in the hypoglossal canal with no contrast enhancement and high signal on T2-weighted imaging. The lesion was assumed to be a cystic schwannoma of the hypoglossal nerve. Stereotactic irradiation was considered, but in accordance with the patient's wishes, surgical exploration was performed. This revealed that, rather than a schwannoma, the patient had an intraneural ganglion cyst, retrospectively contraindicating irradiation as an option. This case illustrates a very rare location of an intraneural ganglion cyst in the hypoglossal nerve. To our knowledge there are no previous reports of an intraneural ganglion cyst confined to the hypoglossal canal. PMID:26251801

  3. Pudendal Nerve Entrapment Syndrome due to a Ganglion Cyst: A Case Report

    PubMed Central

    2016-01-01

    Pudendal nerve entrapment syndrome is an unusual cause of chronic pelvic pain. We experienced a case of pudendal neuralgia associated with a ganglion cyst. A 60-year-old male patient with a tingling sensation and burning pain in the right buttock and perineal area visited our outpatient rehabilitation center. Pelvis magnetic resonance imaging showed the presence of multiple ganglion cysts around the right ischial spine and sacrospinous ligament, and the pudendal nerve and vessel bundle were located between the ischial spine and ganglion cyst at the entrance of Alcock's canal. We aspirated the lesions under ultrasound guidance, and consequently his symptoms subsided during a 6-month follow-up. This is the first report of pudendal neuralgia caused by compression from a ganglion cyst around the sacrospinous ligament. PMID:27606282

  4. Nicotinic Antagonists Enhance Process Outgrowth by Rat Retinal Ganglion Cells in Culture

    NASA Astrophysics Data System (ADS)

    Lipton, Stuart A.; Frosch, Matthew P.; Phillips, Micheal D.; Tauck, David L.; Aizenman, Elias

    1988-03-01

    Functional nicotinic cholinergic receptors are found on mammalian retinal ganglion cell neurons in culture. The neurotransmitter acetylcholine (ACh) can be detected in the medium of many of these retinal cultures, after release presumably from the choline acetyltransferase-positive amacrine cells. The postsynaptic effect of endogenous or applied ACh on the ganglion cells can be blocked with specific nicotinic antagonists. Here it is shown that within 24 hours of producing such a pharmacologic blockade, the retinal ganglion cells begin to sprout or regenerate neuronal processes. Thus, the growth-enhancing effect of nicotinic antagonists may be due to the removal of inhibition to growth by tonic levels of ACh present in the culture medium. Since there is a spontaneous leak of ACh in the intact retina, the effects of nicotinic cholinergic drugs on process outgrowth in culture may reflect a normal control mechanism for growth or regeneration of retinal ganglion cell processes that is exerted by ACh in vivo.

  5. Pudendal Nerve Entrapment Syndrome due to a Ganglion Cyst: A Case Report.

    PubMed

    Lee, Jae Wook; Lee, Sung-Moon; Lee, Dong Gyu

    2016-08-01

    Pudendal nerve entrapment syndrome is an unusual cause of chronic pelvic pain. We experienced a case of pudendal neuralgia associated with a ganglion cyst. A 60-year-old male patient with a tingling sensation and burning pain in the right buttock and perineal area visited our outpatient rehabilitation center. Pelvis magnetic resonance imaging showed the presence of multiple ganglion cysts around the right ischial spine and sacrospinous ligament, and the pudendal nerve and vessel bundle were located between the ischial spine and ganglion cyst at the entrance of Alcock's canal. We aspirated the lesions under ultrasound guidance, and consequently his symptoms subsided during a 6-month follow-up. This is the first report of pudendal neuralgia caused by compression from a ganglion cyst around the sacrospinous ligament. PMID:27606282

  6. Large Ganglion Cyst with Unusual Location on the Back—A Case Report

    PubMed Central

    Nielsen, Thomas Wagner; Berg, Jais Oliver

    2016-01-01

    Summary: A ganglion cyst is a soft tissue tumor-like lesion filled with colloid material commonly located on the hand and wrist. We report a case of a large ganglion cyst with an unusual location on the back. The patient presented with a mass growing over 2 months measuring 11.2 × 4.7 × 7.2 cm on magnetic resonance imaging. Ultrasound and puncture was attempted twice without achieving drainage. After surgical removal, histologic examination diagnosed the tumor as a ganglion cyst. We conclude that when evaluating a subcutaneous soft tissue mass, regardless of localization, a ganglion cyst may be a differential diagnosis. PMID:27482477

  7. An open-source computational tool to automatically quantify immunolabeled retinal ganglion cells.

    PubMed

    Dordea, Ana C; Bray, Mark-Anthony; Allen, Kaitlin; Logan, David J; Fei, Fei; Malhotra, Rajeev; Gregory, Meredith S; Carpenter, Anne E; Buys, Emmanuel S

    2016-06-01

    A fully automated and robust method was developed to quantify β-III-tubulin-stained retinal ganglion cells, combining computational recognition of individual cells by CellProfiler and a machine-learning tool to teach phenotypic classification of the retinal ganglion cells by CellProfiler Analyst. In animal models of glaucoma, quantification of immunolabeled retinal ganglion cells is currently performed manually and remains time-consuming. Using this automated method, quantifications of retinal ganglion cell images were accelerated tenfold: 1800 images were counted in 3 h using our automated method, while manual counting of the same images took 72 h. This new method was validated in an established murine model of microbead-induced optic neuropathy. The use of the publicly available software and the method's user-friendly design allows this technique to be easily implemented in any laboratory. PMID:27119563

  8. Case Report: Intraneural Intracanalicular Ganglion Cyst of the Hypoglossal Nerve Treated by Extradural Transcondylar Approach.

    PubMed

    Bilgin-Freiert, Arzu; Fugleholm, Kåre; Poulsgaard, Lars

    2015-07-01

    We report a case of an intraneural ganglion cyst of the hypoglossal canal. The patient presented with unilateral hypoglossal nerve palsy, and magnetic resonance imaging showed a small lesion in the hypoglossal canal with no contrast enhancement and high signal on T2-weighted imaging. The lesion was assumed to be a cystic schwannoma of the hypoglossal nerve. Stereotactic irradiation was considered, but in accordance with the patient's wishes, surgical exploration was performed. This revealed that, rather than a schwannoma, the patient had an intraneural ganglion cyst, retrospectively contraindicating irradiation as an option. This case illustrates a very rare location of an intraneural ganglion cyst in the hypoglossal nerve. To our knowledge there are no previous reports of an intraneural ganglion cyst confined to the hypoglossal canal. PMID:26251801

  9. Compression of the palmar cutaneous nerve by ganglions of the wrist.

    PubMed

    Gessini, L; Jandolo, B; Pietrangeli, A; Senese, A

    1983-01-01

    Two cases of compression of the palmar cutaneous nerve by ganglion of the wrist are presented. The anatomy of the region, compression factors, mechanism and clinical features are discussed. Timely surgical removal of compression is recommended. PMID:6674421

  10. A ganglion cyst derived from a synovial cyst: A case report.

    PubMed

    Kizilay, Zahir; Yilmaz, Ali; Gurcan, Sevilay; Berber, Osman; Ozsunar, Yelda; Eliyatkın, Nuket

    2015-01-01

    The synovial and ganglion cysts originating from the facet joint have been named under the name of the Juxtafacet cyst by the several researchers. They put forward that the synovial cyst originated from the synovial joint. But, they failed to clarify the pathophysiology of the formation of the ganglion cyst. In this case report, we reported a 67-year-old male patient was referred to the emergency from another center with the complaint of a left leg pain and weakness in the left foot and patient was treated with microchirurgical technique. His patological examination was evaluated a ganglion cyst. We have discussed and explained the pathophysiology of the formation of a ganglion cyst derivered from a synovial cyst. And separately, we have presented the spinal cysts by grouping them under a new classification called a cystic formation of the soft tissue attachments of the mobile spine as well as dividing them into sub-groups. PMID:26652879

  11. Photovoltaic restoration of sight with high visual acuity in rats with retinal degeneration

    NASA Astrophysics Data System (ADS)

    Palanker, D.; Goetz, G.; Lorach, H.; Mandel, Y.; Smith, R.; Boinagrov, D.; Lei, X.; Kamins, T.; Harris, J.; Mathieson, K.; Sher, A.

    2015-03-01

    Patients with retinal degeneration lose sight due to gradual demise of photoreceptors. Electrical stimulation of the surviving retinal neurons provides an alternative route for delivery of visual information. Subretinal photovoltaic arrays with 70μm pixels were used to convert pulsed near-IR light (880-915nm) into pulsed current to stimulate the nearby inner retinal neurons. Network-mediated responses of the retinal ganglion cells (RGCs) could be modulated by pulse width (1-20ms) and peak irradiance (0.5-10 mW/mm2). Similarly to normal vision, retinal response to prosthetic stimulation exhibited flicker fusion at high frequencies, adaptation to static images, and non-linear spatial summation. Spatial resolution was assessed in-vitro and in-vivo using alternating gratings with variable stripe width, projected with rapidly pulsed illumination (20-40Hz). In-vitro, average size of the electrical receptive fields in normal retina was 248+/-59μm - similar to their visible light RF size: 249+/-44μm. RGCs responded to grating stripes down to 67μm using photovoltaic stimulation in degenerate rat retina, and 28μm with visible light in normal retina. In-vivo, visual acuity in normally-sighted controls was 29+/-5μm/stripe, vs. 63+/-4μm/stripe in rats with subretinal photovoltaic arrays, corresponding to 20/250 acuity in human eye. With the enhanced acuity provided by eye movements and perceptual learning in human patients, visual acuity might exceed the 20/200 threshold of legal blindness. Ease of implantation and tiling of these wireless arrays to cover a large visual field, combined with their high resolution opens the door to highly functional restoration of sight.

  12. A Novel Retinal Oscillation Mechanism in an Autosomal Dominant Photoreceptor Degeneration Mouse Model.

    PubMed

    Tu, Hung-Ya; Chen, Yu-Jiun; McQuiston, Adam R; Chiao, Chuan-Chin; Chen, Ching-Kang

    2015-01-01

    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 excitatory postsynaptic current (EPSC) oscillation and non-rhythmic inhibitory postsynaptic current (IPSC) 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. PMID:26793064

  13. A Novel Retinal Oscillation Mechanism in an Autosomal Dominant Photoreceptor Degeneration Mouse Model

    PubMed Central

    Tu, Hung-Ya; Chen, Yu-Jiun; McQuiston, Adam R.; Chiao, Chuan-Chin; Chen, Ching-Kang

    2016-01-01

    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 excitatory postsynaptic current (EPSC) oscillation and non-rhythmic inhibitory postsynaptic current (IPSC) 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. PMID:26793064

  14. A wonderful network unraveled - Detailed description of capillaries in the prosomal ganglion of scorpions

    PubMed Central

    2014-01-01

    Introduction Though it has long been known that the prosomal ganglion of scorpions is supplied by a dense system of arteries, the pattern of this network has never been described and analyzed in detail. Using MicroCT in combination with computer aided 3D-reconstruction we provide the first detailed description of the pattern of arteries in the prosomal ganglion of Brotheas granulatus (Scorpiones, Chactidae) and other scorpion species. Results The entire prosomal ganglion in scorpions is supplied by a network of arteries that branch off the major arteries of the anterior aorta system. The most prominent of these are the nine transganglionic arteries which run through the nerve mass along the midline of the body and branch terminally, i.e. below the neuropils, into smaller arteries. These arteries reticulate into a dense network between the surrounding somata and the centrally located neuropil structures of the ganglion. Conclusions We demonstrate the presence in the prosomal ganglion of scorpions of a capillary system made up of afferent arteries which deliver hemolymph into the ganglion and efferent arteries which transport the hemolymph out of the ganglion. Adopting the structural definition used for vertebrate circulatory systems, this capillary network can also be termed a bipolar rete mirabile (located as it is between afferent and efferent arteries) analogous to those found in vertebrates and some echinoderms. Within the rete mirabile of the scorpion prosomal ganglion, some regions (i.e. neuropils) are better supplied than others. The structural information provided here can now be used in functional neuronal studies to determine the physiological and computational significance of the various neuropils in the complex scorpion nervous system. PMID:24812570

  15. Extensor tendon lacerations from arthroscopic excision of dorsal wrist ganglion: case report.

    PubMed

    Cooper, Anna R; Elfar, John C

    2013-10-01

    Arthroscopy is an accepted technique for the resection of wrist ganglions. The reported complication rate is comparable with open resection at 2%; however, this rate may be underestimated. Most reported complications are relatively benign and self-limited. In this case report, we detail lacerations of multiple digital extensor tendons from arthroscopic resection of a dorsal ganglion and describe our management of this complication. PMID:23993041

  16. Intraosseous ganglion of the distal tibia: clinical, radiological, and operative management.

    PubMed

    Sedeek, Sedeek Mohamed; Choudry, Q; Garg, S

    2015-01-01

    Intraosseous ganglia are benign cystic lesions located in the subchondral bone. Intraosseous ganglion cysts of the ankle are relatively uncommon. We present a case of recurrent intraosseous ganglion in the ankle of a 41-year-old female who had recurrence after initial surgery. She was treated effectively by curettage and autogenous cancellous bone grafting. At the final follow-up, satisfactory results were obtained with no recurrence or complications. PMID:25664195

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

    PubMed Central

    Manuel, Martine; Pratt, Thomas; Liu, Min; Jeffery, Glen; Price, David J

    2008-01-01

    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 contralateral optic tracts at the

  18. NEUTRINO PROCESSES IN PARTIALLY DEGENERATE NEUTRON MATTER

    SciTech Connect

    Bacca, S.; Hally, K.; Liebendoerfer, M.; Perego, A.; Pethick, C. J.; Schwenk, A.

    2012-10-10

    We investigate neutrino processes for conditions reached in simulations of core-collapse supernovae. In regions where neutrino-matter interactions play an important role, matter is partially degenerate, and we extend earlier work that addressed the degenerate regime. We derive expressions for the spin structure factor in neutron matter, which is a key quantity required for evaluating rates of neutrino processes. We show that, for essentially all conditions encountered in the post-bounce phase of core-collapse supernovae, it is a very good approximation to calculate the spin relaxation rates in the nondegenerate limit. We calculate spin relaxation rates based on chiral effective field theory interactions and find that they are typically a factor of two smaller than those obtained using the standard one-pion-exchange interaction alone.

  19. Inflammation in intervertebral disc degeneration and regeneration

    PubMed Central

    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. Macular degeneration in an arc welder.

    PubMed

    Kim, Eun A; Kim, Byung-Gyu; Yi, Cheol-Ho; Kim, Il Gon; Chae, Chang-Ho; Kang, Seong-Kyu

    2007-04-01

    A male welder who had been working in an industrial machine plant for more than 20 years experienced acute intense pain in his left eye with continuous lacrimation while performing arc welding in 1997. Later in 1997, at the age of 39 yr, macular edema was found in his left eye. He was diagnosed with macular degeneration (MD) of the left eye in 2002, and with right eye MD in 2004. Radiation in the visible and near infrared (IR) spectra penetrates the eye and is absorbed by the retina, possibly causing thermal or photochemical damage. Such retinal damage may be permanent and, therefore, sight-threatening. The young age and history of an acute painful eye injury are not consistent with age related macular degeneration (AMD) but rather is likely maculopathy caused by welding arc exposure. PMID:17485886

  1. Shell nuclear explosions in degenerate dwarfs

    NASA Astrophysics Data System (ADS)

    Kuznetsov, O. A.; Tutukov, A. V.; Chechetkin, V. M.

    1989-08-01

    Numerical gas dynamics simulations are used to study shell nuclear explosions of degenerate carbon-oxygen dwarfs with masses of 1.17, 1.36, and 1.42 solar masses. It is assumed that the calorific capacity of the burning shell matter is between 5 X 10 to the 17th and 5 X 10 to the 18th erg/g. It is shown that, at a low calorific capacity, a remnant may form if the mass of the shell is less than 90 percent of the mass of the degenerate dwarf. In the case of high calorific capacity, a remnant may form only if the mass of the shell is less than half of the dwarf's mass.

  2. Cell type-specific bipolar cell input to ganglion cells in the mouse retina.

    PubMed

    Neumann, S; Hüser, L; Ondreka, K; Auler, N; Haverkamp, S

    2016-03-01

    Many distinct ganglion cell types, which are the output elements of the retina, were found to encode for specific features of a visual scene such as contrast, color information or movement. The detailed composition of retinal circuits leading to this tuning of retinal ganglion cells, however, is apart from some prominent examples, largely unknown. Here we aimed to investigate if ganglion cell types in the mouse retina receive selective input from specific bipolar cell types or if they sample their synaptic input non-selectively from all bipolar cell types stratifying within their dendritic tree. To address this question we took an anatomical approach and immunolabeled retinae of two transgenic mouse lines (GFP-O and JAM-B) with markers for ribbon synapses and type 2 bipolar cells. We morphologically identified all green fluorescent protein (GFP)-expressing ganglion cell types, which co-stratified with type 2 bipolar cells and assessed the total number of bipolar input synapses and the proportion of synapses deriving from type 2 bipolar cells. Only JAM-B ganglion cells received synaptic input preferentially from bipolar cell types other than type 2 bipolar cells whereas the other analyzed ganglion cell types sampled their bipolar input most likely from all bipolar cell terminals within their dendritic arbor. PMID:26751712

  3. Pilot evaluation of a stellate ganglion block for the treatment of hot flashes

    PubMed Central

    Pachman, Deirdre R.; Barton, Debra; Carns, Paul E.; Novotny, Paul J.; Wolf, Sherry; Linquist, Breanna; Kohli, Sadhna; Smith, DeAnne R.; Loprinzi, Charles L.

    2011-01-01

    Purpose Hot flashes are a significant problem in breast cancer patients, especially because the most effective therapy, estrogen, is often contraindicated. Based on recent pilot data from a single group supporting the use of a stellate ganglion block for the treatment of hot flashes, the present pilot trial was done to further evaluate the hypothesis that a stellate ganglion block may be a safe and effective therapy for hot flashes. Methods In women with breast cancer who had hot flashes, a stellate ganglion block was performed after 1 week of baseline hot flash data collection. The main efficacy measures were the changes from baseline in hot flash frequency and hot flash score during the 6th week. Results Ten patients were enrolled between 4/23/2009 and 7/10/2009; eight patients were evaluable. After the stellate ganglion block, the mean hot flash frequency and score decreased from baseline values by over 60% during some of the post-treatment weeks. The mean hot flash frequency and score at week 6 decreased from baseline values by 44% and 45%, respectively. There were no significant adverse events clearly attributed to the stellate ganglion blocks. Conclusions The results of this pilot trial support that stellate ganglion blocks may be a helpful therapy for hot flashes. A prospective placebo-controlled clinical trial should be done to more definitively determine this contention. PMID:20496155

  4. Broad Thorny Ganglion Cells: A Candidate for Visual Pursuit Error Signaling in the Primate Retina

    PubMed Central

    Manookin, Michael B.; Neitz, Jay; Rieke, Fred

    2015-01-01

    Functional analyses exist only for a few of the morphologically described primate ganglion cell types, and their correlates in other mammalian species remain elusive. Here, we recorded light responses of broad thorny cells in the whole-mounted macaque retina. They showed ON-OFF-center light responses that were strongly suppressed by stimulation of the receptive field surround. Spike responses were delayed compared with parasol ganglion cells and other ON-OFF cells, including recursive bistratified ganglion cells and A1 amacrine cells. The receptive field structure was shaped by direct excitatory synaptic input and strong presynaptic and postsynaptic inhibition in both ON and OFF pathways. The cells responded strongly to dark or bright stimuli moving either in or out of the receptive field, independent of the direction of motion. However, they did not show a maintained spike response either to a uniform background or to a drifting plaid pattern. These properties could be ideally suited for guiding movements involved in visual pursuit. The functional characteristics reported here permit the first direct cross-species comparison of putative homologous ganglion cell types. Based on morphological similarities, broad thorny ganglion cells have been proposed to be homologs of rabbit local edge detector ganglion cells, but we now show that the two cells have quite distinct physiological properties. Thus, our data argue against broad thorny cells as the homologs of local edge detector cells. PMID:25834063

  5. Ouabain-induced cochlear nerve degeneration: synaptic loss and plasticity in a mouse model of auditory neuropathy.

    PubMed

    Yuan, Yasheng; Shi, Fuxin; Yin, Yanbo; Tong, Mingjie; Lang, Hainan; Polley, Daniel B; Liberman, M Charles; Edge, Albert S B

    2014-02-01

    Ouabain application to the round window can selectively destroy type-I spiral ganglion cells, producing an animal model of auditory neuropathy. To assess the long-term effects of this deafferentation on synaptic organization in the organ of Corti and cochlear nucleus, and to ask whether surviving cochlear neurons show any post-injury plasticity in the adult, we quantified the peripheral and central synapses of type-I neurons at posttreatment times ranging from 1 to 3 months. Measures of normal DPOAEs and greatly reduced auditory brainstem responses (ABRs) confirmed the neuropathy phenotype. Counts of presynaptic ribbons and postsynaptic glutamate receptor patches in the inner hair cell area decreased with post-exposure time, as did counts of cochlear nerve terminals in the cochlear nucleus. Although these counts provided no evidence of new synapse formation via branching from surviving neurons, the regular appearance of ectopic neurons in the inner hair cell area suggested that neurite extension is not uncommon. Correlations between pathophysiology and histopathology showed that ABR thresholds are very insensitive to even massive neural degeneration, whereas the amplitude of ABR wave 1 is a better metric of synaptic degeneration. PMID:24113829

  6. Effect of trapping in degenerate quantum plasmas

    SciTech Connect

    Shah, H. A.; Qureshi, M. N. S.; Tsintsadze, N.

    2010-03-15

    In the present work we consider the effect of trapping as a microscopic process in a plasma consisting of quantum electrons and nondegenerate ions. The formation of solitary structures is investigated in two cases: first when the electrons are fully degenerate and second when small temperature effects are taken into account. It is seen that not only rarefactive but coupled rarefactive and compressive solitons are obtained under different temperature conditions.

  7. Degenerate Bose gases with uniform loss

    NASA Astrophysics Data System (ADS)

    Grišins, Pjotrs; Rauer, Bernhard; Langen, Tim; Schmiedmayer, Jörg; Mazets, Igor E.

    2016-03-01

    We theoretically investigate a weakly interacting degenerate Bose gas coupled to an empty Markovian bath. We show that in the universal phononic limit the system evolves towards an asymptotic state where an emergent temperature is set by the quantum noise of the outcoupling process. For situations typically encountered in experiments, this mechanism leads to significant cooling. Such dissipative cooling supplements conventional evaporative cooling and dominates in settings where thermalization is highly suppressed, such as in a one-dimensional quasicondensate.

  8. Equilibrium configurations of degenerate fluid spheres

    SciTech Connect

    Whitman, P.G.

    1985-04-01

    Equilibrium configurations of degenerate fluid spheres which assume a polytropic form in the ultrahigh-density regime are considered. We show that analytic solutions more general than those of Misner and Zapolsky exist which possess the asymptotic equation of state. Simple expressions are derived which indicate this nature of the fluids in the extreme relativistic limit, and the stability of these interiors is considered in the asymptotic region.

  9. Calabi-Yau manifolds and their degenerations.

    PubMed

    Tosatti, Valentino

    2012-07-01

    Calabi-Yau manifolds are geometric objects of central importance in several branches of mathematics, including differential geometry, algebraic geometry, and mathematical physics. In this paper, we give a brief introduction to the subject aimed at a general mathematical audience and present some of our results that shed some light on the possible ways in which families of Calabi-Yau manifolds can degenerate. PMID:22257362

  10. Recombination-generation currents in degenerate semiconductors

    NASA Technical Reports Server (NTRS)

    Von Roos, O.

    1978-01-01

    The classical Shockley-Read-Hall theory of free carrier recombination and generation via traps is extended to degenerate semiconductors. A concise and simple expression is found which avoids completely the concept of a Fermi level, a concept which is alien to nonequilibrium situations. Assumptions made in deriving the recombination generation current are carefully delineated and are found to be basically identical to those made in the original theory applicable to nondegenerate semiconductors.

  11. Asymmetrical alien hands in corticobasal degeneration.

    PubMed

    Fitzgerald, David B; Drago, Valeria; Jeong, Yong; Chang, Yu-Ling; White, Keith D; Heilman, Kenneth M

    2007-03-15

    There are several forms of alien limb, but alien limb in corticobasal degeneration (CBD) is not well understood. We studied a patient with CBD who demonstrated two different types of alien limb. With his right hand he demonstrated a tactile avoidance response with levitation. With his left hand, he demonstrated continuous tactile pursuit of the examiner's hand ("tactile mitgehen"). Mitgehen is often associated with frontal dysfunction, but avoidance response and levitation are often associated with parietal dysfunction. PMID:17230447

  12. Dichromatic Langmuir waves in degenerate quantum plasma

    SciTech Connect

    Dubinov, A. E. Kitayev, I. N.

    2015-06-15

    Langmuir waves in fully degenerate quantum plasma are considered. It is shown that, in the linear approximation, Langmuir waves are always dichromatic. The low-frequency component of the waves corresponds to classical Langmuir waves, while the high-frequency component, to free-electron quantum oscillations. The nonlinear problem on the profile of dichromatic Langmuir waves is solved. Solutions in the form of a superposition of waves and in the form of beatings of its components are obtained.

  13. Inertial fusion features in degenerate plasmas

    NASA Astrophysics Data System (ADS)

    León, Pablo T.; Eliezer, Shalom; Piera, Mireia; Martínez-Val, José M.

    2005-04-01

    Very high plasma densities can be obtained at the end of the implosion phase in inertial fusion targets, particularly in the so-called fast-ignition scheme (Tabak et al., 1994; Mulser & Bauer, 2004), where a central hot spark is not needed at all. By properly tailoring the fuel compression stage, degenerate states can be reached (Azechi et al., 1991; Nakai et al., 1991; McCory, 1998). In that case, most of the relevant energy transfer mechanisms involving electrons are affected (Honrubia & Tikhonchuk, 2004; Bibi & Matte, 2004; Bibi et al., 2004). For instance, bremsstrahlung emission is highly suppressed (Eliezer et al., 2003). In fact, a low ignition-temperature regime appears at very high plasma densities, due to radiation leakage reduction (León et al., 2001). Stopping power and ion-electron coulomb collisions are also changed in this case, which are important mechanisms to trigger ignition by the incoming fast jet, and to launch the fusion wave from the igniting region into the colder, degenerate plasma. All these points are reviewed in this paper. Although degenerate states would not be easy to obtain by target implosion, they present a very interesting upper limit that deserves more attention in order to complete the understanding on the different domains for inertial confinement fusion.

  14. Buoyancy instabilities in degenerate, collisional, magnetized plasmas

    NASA Astrophysics Data System (ADS)

    Chang, Philip; Quataert, Eliot

    2010-03-01

    In low-collisionality plasmas, anisotropic heat conduction due to a magnetic field leads to buoyancy instabilities for any non-zero temperature gradient. We study analogous instabilities in degenerate collisional plasmas, i.e. when the electron collision frequency is large compared to the electron cyclotron frequency. Although heat conduction is nearly isotropic in this limit, the small residual anisotropy ensures that collisional degenerate plasmas are also convectively unstable independent of the sign of the temperature gradient. We show that the range of wavelengths that are unstable is independent of the magnetic field strength, while the growth time increases with decreasing magnetic field strength. We discuss the application of these collisional buoyancy instabilities to white dwarfs and neutron stars. Magnetic tension and the low specific heat of a degenerate plasma significantly limit their effectiveness; the most promising venues for growth are in the liquid oceans of young, weakly magnetized neutron stars (B <~ 109 G) and in the cores of young, high magnetic field white dwarfs (B ~ 109 G).

  15. Propagation of disturbances in degenerate quantum systems

    NASA Astrophysics Data System (ADS)

    Chancellor, Nicholas; Haas, Stephan

    2011-07-01

    Disturbances in gapless quantum many-body models are known to travel an unlimited distance throughout the system. Here, we explore this phenomenon in finite clusters with degenerate ground states. The specific model studied here is the one-dimensional J1-J2 Heisenberg Hamiltonian at and close to the Majumdar-Ghosh point. Both open and periodic boundary conditions are considered. Quenches are performed using a local magnetic field. The degenerate Majumdar-Ghosh ground state allows disturbances which carry quantum entanglement to propagate throughout the system and thus dephase the entire system within the degenerate subspace. These disturbances can also carry polarization, but not energy, as all energy is stored locally. The local evolution of the part of the system where energy is stored drives the rest of the system through long-range entanglement. We also examine approximations for the ground state of this Hamiltonian in the strong field limit and study how couplings away from the Majumdar-Ghosh point affect the propagation of disturbances. We find that even in the case of approximate degeneracy, a disturbance can be propagated throughout a finite system.

  16. Gain-of-function nature of Cav1.4 L-type calcium channels alters firing properties of mouse retinal ganglion cells

    PubMed Central

    Knoflach, Dagmar; Schicker, Klaus; Glösmann, Martin; Koschak, Alexandra

    2015-01-01

    Proper function of Cav1.4 L-type calcium channels is crucial for neurotransmitter release in the retina. Our understanding about how different levels of Cav1.4 channel activity affect retinal function is still limited. In the gain-of-function mouse model Cav1.4-IT we expected a reduction in the photoreceptor dynamic range but still transmission toward retinal ganglion cells. A fraction of Cav1.4-IT ganglion cells responded to light stimulation in multielectrode array recordings from whole-mounted retinas, but showed a significantly delayed response onset. Another significant number of cells showed higher activity in darkness. In addition to structural remodeling observed at the first retinal synapse of Cav1.4-IT mice the functional data suggested a loss of contrast enhancement, a fundamental feature of our visual system. In fact, Cav1.4-IT mouse retinas showed a decline in spatial response and changes in their contrast sensitivity profile. Photoreceptor degeneration was obvious from the nodular structure of cone axons and enlarged pedicles which partly moved toward the outer nuclear layer. Loss of photoreceptors was also expressed as reduced expression of proteins involved in chemical and electrical transmission, as such metabotropic glutamate receptor mGluR6 and the gap junction protein Connexin 36. Such gross changes in retinal structure and function could also explain the diminished visual performance of CSNB2 patients. The expression pattern of the plasma-membrane calcium ATPase 1 which participates in the maintenance of the intracellular calcium homeostasis in photoreceptors was changed in Cav1.4-IT mice. This might be part of a protection mechanism against increased calcium influx, as this is suggested for Cav1.4-IT channels. PMID:26274509

  17. Gain-of-function nature of Cav1.4 L-type calcium channels alters firing properties of mouse retinal ganglion cells.

    PubMed

    Knoflach, Dagmar; Schicker, Klaus; Glösmann, Martin; Koschak, Alexandra

    2015-01-01

    Proper function of Cav1.4 L-type calcium channels is crucial for neurotransmitter release in the retina. Our understanding about how different levels of Cav1.4 channel activity affect retinal function is still limited. In the gain-of-function mouse model Cav1.4-IT we expected a reduction in the photoreceptor dynamic range but still transmission toward retinal ganglion cells. A fraction of Cav1.4-IT ganglion cells responded to light stimulation in multielectrode array recordings from whole-mounted retinas, but showed a significantly delayed response onset. Another significant number of cells showed higher activity in darkness. In addition to structural remodeling observed at the first retinal synapse of Cav1.4-IT mice the functional data suggested a loss of contrast enhancement, a fundamental feature of our visual system. In fact, Cav1.4-IT mouse retinas showed a decline in spatial response and changes in their contrast sensitivity profile. Photoreceptor degeneration was obvious from the nodular structure of cone axons and enlarged pedicles which partly moved toward the outer nuclear layer. Loss of photoreceptors was also expressed as reduced expression of proteins involved in chemical and electrical transmission, as such metabotropic glutamate receptor mGluR6 and the gap junction protein Connexin 36. Such gross changes in retinal structure and function could also explain the diminished visual performance of CSNB2 patients. The expression pattern of the plasma-membrane calcium ATPase 1 which participates in the maintenance of the intracellular calcium homeostasis in photoreceptors was changed in Cav1.4-IT mice. This might be part of a protection mechanism against increased calcium influx, as this is suggested for Cav1.4-IT channels. PMID:26274509

  18. Enriched retinal ganglion cells derived from human embryonic stem cells

    PubMed Central

    Gill, Katherine P.; Hung, Sandy S. C.; Sharov, Alexei; Lo, Camden Y.; Needham, Karina; Lidgerwood, Grace E.; Jackson, Stacey; Crombie, Duncan E.; Nayagam, Bryony A.; Cook, Anthony L.; Hewitt, Alex W.; Pébay, Alice; Wong, Raymond C. B.

    2016-01-01

    Optic neuropathies are characterised by a loss of retinal ganglion cells (RGCs) that lead to vision impairment. Development of cell therapy requires a better understanding of the signals that direct stem cells into RGCs. Human embryonic stem cells (hESCs) represent an unlimited cellular source for generation of human RGCs in vitro. In this study, we present a 45-day protocol that utilises magnetic activated cell sorting to generate enriched population of RGCs via stepwise retinal differentiation using hESCs. We performed an extensive characterization of these stem cell-derived RGCs by examining the gene and protein expressions of a panel of neural/RGC markers. Furthermore, whole transcriptome analysis demonstrated similarity of the hESC-derived RGCs to human adult RGCs. The enriched hESC-RGCs possess long axons, functional electrophysiological profiles and axonal transport of mitochondria, suggestive of maturity. In summary, this RGC differentiation protocol can generate an enriched population of functional RGCs from hESCs, allowing future studies on disease modeling of optic neuropathies and development of cell therapies. PMID:27506453

  19. Developmental mechanisms that regulate retinal ganglion cell dendritic morphology

    PubMed Central

    Tian, Ning

    2011-01-01

    One of the fundamental features of retinal ganglion cells (RGCs) is that dendrites of individual RGCs are confined to one or a few narrow strata within the inner plexiform layer (IPL), and each RGC synapses only with a small group of presynaptic bipolar and amacrine cells with axons/dendrites ramified in the same strata to process distinct visual features. The underlying mechanisms which control the development of this laminar-restricted distribution pattern of RGC dendrites have been extensively studied, and it is still an open question whether the dendritic pattern of RGCs is determined by molecular cues or by activity-dependent refinement. Accumulating evidence suggests that both molecular cues and activity-dependent refinement might regulate RGC dendrites in a cell subtype-specific manner. However, identification of morphological subtypes of RGCs before they have achieved their mature dendritic pattern is a major challenge in the study of RGC dendritic development. This problem is now being circumvented through the use of molecular markers in genetically engineered mouse lines to identify RGC subsets early during development. Another unanswered fundamental question in the study of activity-dependent refinement of RGC dendrites is how changes in synaptic activity lead to the changes in dendritic morphology. Recent studies have started to shed light on the molecular basis of activity-dependent dendritic refinement of RGCs by showing that some molecular cascades control the cytoskeleton reorganization of RGCs. PMID:21542137

  20. Cytoarchitectonic study of the trigeminal ganglion in humans

    PubMed Central

    KRASTEV, DIMO STOYANOV; APOSTOLOV, ALEXANDER

    2013-01-01

    The trigeminal ganglion (TG), a cluster of pseudounipolar neurons, is located in the trigeminal impression of the temporal pyramid. It is covered by a sheath of the dura mater and arachnoid and is near the rear end of the cavernous sinus. The peripheral processes of the pseudounipolar cells are involved in the formation of the first and second branch and the sensory part of the third branch of the fifth cranial nerve, and the central ones form the sensory root of the nerve, which penetrates at the level of the middle cerebellar peduncle, aside from the pons, and terminate in the sensory nuclei of the trigeminal complex. We found that the primary sensory neurons involved in sensory innervation of the orofacial complex are a diverse group. Although they possess the general structure of pseudounipolar neurons, there are significant differences among them, seen in varying intensities of staining. Based on our investigations we classified the neurons into 7 groups, i.e. large, subdivided into light and dark, medium, also light and dark, and small light and dark, and, moreover, neurons with an irregular shape of their perikarya. Further research by applying various immunohistochemical methods will clarify whether differences in the morphological patterns of the neurons are associated with differences in the neurochemical composition of various neuronal types. PMID:26527926

  1. Imaging retinal ganglion cells: enabling experimental technology for clinical application.

    PubMed

    Smith, Corey A; Chauhan, Balwantray C

    2015-01-01

    Recent advances in clinical ophthalmic imaging have enhanced patient care. However, the ability to differentiate retinal neurons, such as retinal ganglion cells (RGCs), would advance many areas within ophthalmology, including the screening and monitoring of glaucoma and other optic neuropathies. Imaging at the single cell level would take diagnostics to the next level. Experimental methods have provided techniques and insight into imaging RGCs, however no method has yet to be translated to clinical application. This review provides an overview of the importance of non-invasive imaging of RGCs and the clinically relevant capabilities. In addition, we report on experimental data from wild-type mice that received an in vivo intravitreal injection of a neuronal tracer that labelled RGCs, which in turn were monitored for up to 100 days post-injection with confocal scanning laser ophthalmoscopy. We were able to demonstrate efficient and consistent RGC labelling with this delivery method and discuss the issue of cell specificity. This type of experimental work is important in progressing towards clinically applicable methods for monitoring loss of RGCs in glaucoma and other optic neuropathies. We discuss the challenges to translating these findings to clinical application and how this method of tracking RGCs in vivo could provide valuable structural and functional information to clinicians. PMID:25448921

  2. Enriched retinal ganglion cells derived from human embryonic stem cells.

    PubMed

    Gill, Katherine P; Hung, Sandy S C; Sharov, Alexei; Lo, Camden Y; Needham, Karina; Lidgerwood, Grace E; Jackson, Stacey; Crombie, Duncan E; Nayagam, Bryony A; Cook, Anthony L; Hewitt, Alex W; Pébay, Alice; Wong, Raymond C B

    2016-01-01

    Optic neuropathies are characterised by a loss of retinal ganglion cells (RGCs) that lead to vision impairment. Development of cell therapy requires a better understanding of the signals that direct stem cells into RGCs. Human embryonic stem cells (hESCs) represent an unlimited cellular source for generation of human RGCs in vitro. In this study, we present a 45-day protocol that utilises magnetic activated cell sorting to generate enriched population of RGCs via stepwise retinal differentiation using hESCs. We performed an extensive characterization of these stem cell-derived RGCs by examining the gene and protein expressions of a panel of neural/RGC markers. Furthermore, whole transcriptome analysis demonstrated similarity of the hESC-derived RGCs to human adult RGCs. The enriched hESC-RGCs possess long axons, functional electrophysiological profiles and axonal transport of mitochondria, suggestive of maturity. In summary, this RGC differentiation protocol can generate an enriched population of functional RGCs from hESCs, allowing future studies on disease modeling of optic neuropathies and development of cell therapies. PMID:27506453

  3. Macaque ganglion cell responses to probe stimuli on modulated backgrounds.

    PubMed

    Lee, Barry B; Sun, Hao; Cao, Dingcai

    2010-01-01

    In the natural environment, visual targets have to be detected and identified on changing backgrounds. Here, responses of parasol (magnocellular) ganglion cells to probes on modulated backgrounds are described. At low frequency, the adaptation level of the background influences the probe response, but with increasing frequency there is a strong interaction with the response to the background per se, so that on- and off-center cell responses are modulated in different phases. Interactions with the background response include both thresholding effects (when the cell's firing is suppressed and no pulse response occurs) and saturation effects (when the background response is vigorous the pulse generates few additional spikes). At 30 Hz, the effect of the pulse is largely a suppression or phase shift of the background response. The data are relevant to the probed-sinewave paradigm, in which pulse detection thresholds are modulated with pulse phase relative to a sinusoidal background. The physiological substrates of the psychophysical results with the probed-sinewave paradigm appear complex, with on- and off-center cells likely to contribute to detection at different pulse phases. PMID:21047758

  4. Adaptation to steady light by intrinsically photosensitive retinal ganglion cells.

    PubMed

    Do, Michael Tri Hoang; Yau, King-Wai

    2013-04-30

    Intrinsically photosensitive retinal ganglion cells (ipRGCs) are recently discovered photoreceptors in the mammalian eye. These photoreceptors mediate primarily nonimage visual functions, such as pupillary light reflex and circadian photoentrainment, which are generally expected to respond to the absolute light intensity. The classical rod and cone photoreceptors, on the other hand, mediate image vision by signaling contrast, accomplished by adaptation to light. Experiments by others have indicated that the ipRGCs do, in fact, light-adapt. We found the same but, in addition, have now quantified this light adaptation for the M1 ipRGC subtype. Interestingly, in incremental-flash-on-background experiments, the ipRGC's receptor current showed a flash sensitivity that adapted in background light according to the Weber-Fechner relation, well known to describe the adaptation behavior of rods and cones. Part of this light adaptation by ipRGCs appeared to be triggered by a Ca(2+) influx, in that the flash response elicited in the absence of extracellular Ca(2+) showed a normal rising phase but a slower decay phase, resulting in longer time to peak and higher sensitivity. There is, additionally, a prominent Ca(2+)-independent component of light adaptation not typically seen in rods and cones or in invertebrate rhabdomeric photoreceptors. PMID:23589882

  5. Identical Mutation in a Novel Retinal Gene Causes Progressive Rod-Cone Degeneration (prcd) in Dogs and Retinitis Pigmentosa in Man

    PubMed Central

    Zangerl, Barbara; Goldstein, Orly; Philp, Alisdair R.; Lindauer, Sarah J.P.; Pearce-Kelling, Susan E.; Mullins, Robert F.; Graphodatsky, Alexander S.; Ripoll, Daniel; Felix, Jeanette S.; Stone, Edwin M.; Acland, Gregory M.; Aguirre, Gustavo D.

    2014-01-01

    Progressive rod-cone degeneration (prcd) is a late-onset, autosomal recessive photoreceptor degeneration of dogs, and a homolog for some forms of human retinitis pigmentosa (RP). Previously, the disease relevant interval was reduced to a 106 Kb region on CFA9, and a common phenotype-specific haplotype was identified in all affected dogs from several different breeds, and breed varieties. Screening of a canine retinal EST library identified partial cDNAs for novel candidate genes in the disease relevant interval. The complete cDNA of one of these, PRCD, was cloned in dog, human and mouse. The gene codes for a 54 amino acid (aa) protein in dog and human, and 53 aa protein in the mouse; the first 24 aa, coded for by exon 1, are highly conserved in 14 vertebrate species. A homozygous mutation (TGC → TAC) in the second codon shows complete concordance with the disorder in 18 different dog breeds/breed varieties tested. The same homozygous mutation was identified in a human patient from Bangladesh with autosomal recessive (ar) RP. Expression studies support the predominant expression of this gene in the retina, with equal expression in the retinal pigment epithelium (RPE), photoreceptors and ganglion cell layers. This study provides strong evidence that a mutation in the novel gene, PRCD, is the cause of autosomal recessive retinal degeneration in both dogs and man. PMID:16938425

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

    NASA Technical Reports Server (NTRS)

    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.

  7. Effects of preganglionic denervation and postganglionic axotomy on acetylcholine receptors in the chick ciliary ganglion

    PubMed Central

    1987-01-01

    The regulation of nicotinic acetylcholine receptors (AChRs) in chick ciliary ganglia was examined by using a radiolabeled anti-AChR mAb to quantitate the amount of receptor in ganglion detergent extracts after preganglionic denervation or postganglionic axotomy. Surgical transection of the preganglionic input to the ciliary ganglion in newly hatched chicks caused a threefold reduction in the total number of AChRs within 10 d compared with that present in unoperated contralateral control ganglia. Surgical transection of both the choroid and ciliary nerves emerging from the ciliary ganglion in newly hatched chicks to establish postganglionic axotomy led to a nearly 10-fold reduction in AChRs within 5 d compared with unoperated contralateral ganglia. The declines were specific since they could not be accounted for by changes in ganglionic protein or by decreases in neuronal survival or size. Light microscopy revealed no gross morphological differences between neurons in operated and control ganglia. A second membrane component of cholinergic relevance on chick ciliary ganglion neurons is the alpha-bungarotoxin (alpha-Bgt)-binding component. The alpha-Bgt-binding component also declined in number after either postganglionic axotomy or preganglionic denervation, but appeared to do so with a more rapid time course than did ganglionic AChRs. The results imply that cell-cell interactions in vivo specifically regulate both the number of AChRs and the number of alpha-Bgt-binding components in the ganglion. Regulation of these neuronal cholinergic membrane components clearly differs from that previously described for muscle AChRs. PMID:3667699

  8. Age-related hearing loss: GABA, nicotinic acetylcholine and NMDA receptor expression changes in spiral ganglion neurons of the mouse.

    PubMed

    Tang, X; Zhu, X; Ding, B; Walton, J P; Frisina, R D; Su, J

    2014-02-14

    Age-related hearing loss - presbycusis - is the number one communication disorder and most prevalent neurodegenerative condition of our aged population. Although speech understanding in background noise is quite difficult for those with presbycusis, there are currently no biomedical treatments to prevent, delay or reverse this condition. A better understanding of the cochlear mechanisms underlying presbycusis will help lead to future treatments. Objectives of the present study were to investigate GABAA receptor subunit α1, nicotinic acetylcholine (nACh) receptor subunit β2, and N-methyl-d-aspartate (NMDA) receptor subunit NR1 mRNA and protein expression changes in spiral ganglion neurons (SGN) of the CBA/CaJ mouse cochlea, that occur in age-related hearing loss, utilizing quantitative immunohistochemistry and semi-quantitative reverse transcription polymerase chain reaction (RT-PCR) techniques. We found that auditory brainstem response (ABR) thresholds shifted over 40dB from 3 to 48kHz in old mice compared to young adults. DPOAE thresholds also shifted over 40dB from 6 to 49kHz in old mice, and their amplitudes were significantly decreased or absent in the same frequency range. SGN density decreased with age in basal, middle and apical turns, and SGN density of the basal turn declined the most. A positive correlation was observed between SGN density and ABR wave 1amplitude. mRNA and protein expression of GABAAR α1 and AChR β2 decreased with age in SGNs in the old mouse cochlea. mRNA and protein expression of NMDAR NR1 increased with age in SGNs of the old mice. These findings demonstrate that there are functionally-relevant age-related changes of GABAAR, nAChR, NMDAR expression in CBA mouse SGNs reflecting their degeneration, which may be related to functional changes in cochlear synaptic transmission with age, suggesting biological mechanisms for peripheral age-related hearing loss. PMID:24316061

  9. The glial cell modulator ibudilast attenuates neuroinflammation and enhances retinal ganglion cell viability in glaucoma through protein kinase A signaling.

    PubMed

    Cueva Vargas, Jorge L; Belforte, Nicolas; Di Polo, Adriana

    2016-09-01

    Glaucoma is a neurodegenerative disease and the leading cause of irreversible blindness worldwide. Vision deficits in glaucoma result from the selective loss of retinal ganglion cells (RGC). Glial cell-mediated neuroinflammation has been proposed to contribute to disease pathophysiology, but whether this response is harmful or beneficial for RGC survival is not well understood. To test this, we characterized the role of ibudilast, a clinically approved cAMP phosphodiesterase (PDE) inhibitor with preferential affinity for PDE type 4 (PDE4). Here, we demonstrate that intraocular administration of ibudilast dampened macroglia and microglia reactivity in the retina and optic nerve hence decreasing production of proinflammatory cytokines in a rat model of ocular hypertension. Importantly, ibudilast promoted robust RGC soma survival, prevented axonal degeneration, and improved anterograde axonal transport in glaucomatous eyes without altering intraocular pressure. Intriguingly, ocular hypertension triggered upregulation of PDE4 subtype A in Müller glia, and ibudilast stimulated cAMP accumulation in these cells. Co-administration of ibudilast with Rp-cAMPS, a cell-permeable and non-hydrolysable cAMP analog that inhibits protein kinase A (PKA), completely blocked ibudilast-induced neuroprotection. Collectively, these data demonstrate that ibudilast, a safe and well-tolerated glial cell modulator, attenuates gliosis, decreases levels of proinflammatory mediators, and enhances neuronal viability in glaucoma through activation of the cAMP/PKA pathway. This study provides insight into PDE4 signaling as a potential target to counter the harmful effects associated with chronic gliosis and neuroinflammation in glaucoma. PMID:27163643

  10. Intravitreal injection of forskolin, homotaurine, and L-carnosine affords neuroprotection to retinal ganglion cells following retinal ischemic injury

    PubMed Central

    Adornetto, Annagrazia; Cavaliere, Federica; Varano, Giuseppe Pasquale; Rusciano, Dario; Morrone, Luigi Antonio; Corasaniti, Maria Tiziana; Bagetta, Giacinto; Nucci, Carlo

    2015-01-01

    Purpose Retinal ganglion cell (RGC) death is the final event leading to visual impairment in glaucoma; therefore, identification of neuroprotective strategies able to slow down or prevent the process is one of the main challenges for glaucoma research. The purpose of this study was to evaluate the neuroprotective potential of RGC death induced by the in vivo transient increase in intraocular pressure (IOP) of a combined treatment with forskolin, homotaurine, and L-carnosine. Forskolin (7beta-acetoxy-8, 13-epoxy-1a, 6β, 9a-trihydroxy-labd-14-en-11-one) is an activator of adenylate cyclase that decreases IOP by reducing aqueous humor production and functions as a neuroprotector due to its neurotrophin-stimulating activity. Homotaurine is a natural aminosulfonate compound endowed with neuromodulatory effects, while the dipeptide L-carnosine is known for its antioxidant properties. Methods Retinal ischemia was induced in the right eye of adult male Wistar rats by acutely increasing the IOP. Forskolin, homotaurine, and L-carnosine were intravitreally injected and RGC survival evaluated following retrograde labeling with FluoroGold. Total and phosphorylated Akt and glycogen synthase kinase-3β (GSK-3β) protein levels, as well as calpain activity, were analyzed with western blot. Protein kinase A (PKA) was inhibited by intravitreal injection of H89. Results A synergic neuroprotective effect on RGC survival was observed following the combined treatment with forskolin, homotaurine, and L-carnosine compared to forskolin alone. The observed neuroprotection was associated with reduced calpain activity, upregulation of phosphoinositide 3-kinase (PI3K)/Akt pathway, and inhibition of GSK-3β but was independent from PKA activation and distinct from the hypotensive effects of forskolin. Conclusions A multidrug/multitarget approach, by interfering with several pathways involved in RGC degeneration, may be promising to achieve glaucoma neuroprotection. PMID:26167113

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

    NASA Astrophysics Data System (ADS)

    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.

  12. DRP1 inhibition rescues retinal ganglion cells and their axons by preserving mitochondrial integrity in a mouse model of glaucoma.

    PubMed

    Kim, K-Y; Perkins, G A; Shim, M S; Bushong, E; Alcasid, N; Ju, S; Ellisman, M H; Weinreb, R N; Ju, W-K

    2015-01-01

    Glaucoma is the leading cause of irreversible blindness and is characterized by slow and progressive degeneration of the optic nerve head axons and retinal ganglion cell (RGC), leading to loss of visual function. Although oxidative stress and/or alteration of mitochondrial (mt) dynamics induced by elevated intraocular pressure (IOP) are associated with this neurodegenerative disease, the mechanisms that regulate mt dysfunction-mediated glaucomatous neurodegeneration are poorly understood. Using a mouse model of glaucoma, DBA/2J (D2), which spontaneously develops elevated IOP, as well as an in vitro RGC culture system, we show here that oxidative stress, as evidenced by increasing superoxide dismutase 2 (SOD2) and mt transcription factor A (Tfam) protein expression, triggers mt fission and loss by increasing dynamin-related protein 1 (DRP1) in the retina of glaucomatous D2 mice as well as in cultured RGCs exposed to elevated hydrostatic pressure in vitro. DRP1 inhibition by overexpressing DRP1 K38A mutant blocks mt fission and triggers a subsequent reduction of oxidative stress, as evidenced by decreasing SOD2 and Tfam protein expression. DRP1 inhibition promotes RGC survival by increasing phosphorylation of Bad at serine 112 in the retina and preserves RGC axons by maintaining mt integrity in the glial lamina of glaucomatous D2 mice. These findings demonstrate an important vicious cycle involved in glaucomatous neurodegeneration that starts with elevated IOP producing oxidative stress; the oxidative stress then leads to mt fission and a specific form of mt dysfunction that generates further oxidative stress, thus perpetuating the cycle. Our findings suggest that DRP1 is a potential therapeutic target for ameliorating oxidative stress-mediated mt fission and dysfunction in RGC and its axons during glaucomatous neurodegeneration. Thus, DRP1 inhibition may provide a new therapeutic strategy for protecting both RGCs and their axons in glaucoma and other optic

  13. Protection of Retinal Ganglion Cells and Retinal Vasculature by Lycium Barbarum Polysaccharides in a Mouse Model of Acute Ocular Hypertension

    PubMed Central

    Mi, Xue-Song; Feng, Qian; Lo, Amy Cheuk Yin; Chang, Raymond Chuen-Chung; Lin, Bin; Chung, Sookja Kim; So, Kwok-Fai

    2012-01-01

    Acute ocular hypertension (AOH) is a condition found in acute glaucoma. The purpose of this study is to investigate the protective effect of Lycium barbarum polysaccharides (LBP) and its protective mechanisms in the AOH insult. LBP has been shown to exhibit neuroprotective effect in the chronic ocular hypertension (COH) experiments. AOH mouse model was induced in unilateral eye for one hour by introducing 90 mmHg ocular pressure. The animal was fed with LBP solution (1 mg/kg) or vehicle daily from 7 days before the AOH insult till sacrifice at either day 4 or day 7 post insult. The neuroprotective effects of LBP on retinal ganglion cells (RGCs) and blood-retinal-barrier (BRB) were evaluated. In control AOH retina, loss of RGCs, thinning of IRL thickness, increased IgG leakage, broken tight junctions, and decreased density of retinal blood vessels were observed. However, in LBP-treated AOH retina, there was less loss of RGCs with thinning of IRL thickness, IgG leakage, more continued structure of tight junctions associated with higher level of occludin protein and the recovery of the blood vessel density when compared with vehicle-treated AOH retina. Moreover, we found that LBP provides neuroprotection by down-regulating RAGE, ET-1, Aβ and AGE in the retina, as well as their related signaling pathways, which was related to inhibiting vascular damages and the neuronal degeneration in AOH insults. The present study suggests that LBP could prevent damage to RGCs from AOH-induced ischemic injury; furthermore, through its effects on blood vessel protection, LBP would also be a potential treatment for vascular-related retinopathy. PMID:23094016

  14. The progressive nature of Wallerian degeneration in wild-type and slow Wallerian degeneration (WldS) nerves

    PubMed Central

    Beirowski, Bogdan; Adalbert, Robert; Wagner, Diana; Grumme, Daniela S; Addicks, Klaus; Ribchester, Richard R; Coleman, Michael P

    2005-01-01

    Background The progressive nature of Wallerian degeneration has long been controversial. Conflicting reports that distal stumps of injured axons degenerate anterogradely, retrogradely, or simultaneously are based on statistical observations at discontinuous locations within the nerve, without observing any single axon at two distant points. As axon degeneration is asynchronous, there are clear advantages to longitudinal studies of individual degenerating axons. We recently validated the study of Wallerian degeneration using yellow fluorescent protein (YFP) in a small, representative population of axons, which greatly improves longitudinal imaging. Here, we apply this method to study the progressive nature of Wallerian degeneration in both wild-type and slow Wallerian degeneration (WldS) mutant mice. Results In wild-type nerves, we directly observed partially fragmented axons (average 5.3%) among a majority of fully intact or degenerated axons 37–42 h after transection and 40–44 h after crush injury. Axons exist in this state only transiently, probably for less than one hour. Surprisingly, axons degenerated anterogradely after transection but retrogradely after a crush, but in both cases a sharp boundary separated intact and fragmented regions of individual axons, indicating that Wallerian degeneration progresses as a wave sequentially affecting adjacent regions of the axon. In contrast, most or all WldS axons were partially fragmented 15–25 days after nerve lesion, WldS axons degenerated anterogradely independent of lesion type, and signs of degeneration increased gradually along the nerve instead of abruptly. Furthermore, the first signs of degeneration were short constrictions, not complete breaks. Conclusions We conclude that Wallerian degeneration progresses rapidly along individual wild-type axons after a heterogeneous latent phase. The speed of progression and its ability to travel in either direction challenges earlier models in which clearance of

  15. Vector polarons in a degenerate electron system

    NASA Astrophysics Data System (ADS)

    Clougherty, Dennis P.; Foell, Charles A.

    2004-08-01

    We consider a one-dimensional model of an electron in a doubly (or nearly) degenerate band that interacts with elastic distortions. We show that the electron equations of motion reduce to a set of coupled nonlinear Schrödinger equations. For the case of interband electron-phonon coupling stemming from local Jahn-Teller interactions, multicomponent self-localized polaron solutions-vector polarons- are described and classified. The phase diagram for the different types of vector polarons in this model is presented. By interpreting the components of the orbital doublet as those of spin- (1)/(2) , our results can also be used to describe bound magnetic polarons.

  16. Degenerate Fermi Gas of {sup 87}Sr

    SciTech Connect

    DeSalvo, B. J.; Yan, M.; Mickelson, P. G.; Martinez de Escobar, Y. N.; Killian, T. C.

    2010-07-16

    We report quantum degeneracy in a gas of ultracold fermionic {sup 87}Sr atoms. By evaporatively cooling a mixture of spin states in an optical dipole trap for 10.5 s, we obtain samples well into the degenerate regime with T/T{sub F}=0.26{sub -0.06}{sup +0.05}. The main signature of degeneracy is a change in the momentum distribution as measured by time-of-flight imaging, and we also observe a decrease in evaporation efficiency below T/T{sub F{approx}}0.5.

  17. Pharmacogenetics and age-related macular degeneration.

    PubMed

    Schwartz, Stephen G; Brantley, Milam A

    2011-01-01

    Pharmacogenetics seeks to explain interpatient variability in response to medications by investigating genotype-phenotype correlations. There is a small but growing body of data regarding the pharmacogenetics of both nonexudative and exudative age-related macular degeneration. Most reported data concern polymorphisms in the complement factor H and age-related maculopathy susceptibility 2 genes. At this time, the data are not consistent and no definite conclusions may be drawn. As clinical trials data continue to accumulate, these relationships may become more apparent. PMID:22046503

  18. Asymptotic behavior of degenerate logistic equations

    NASA Astrophysics Data System (ADS)

    Arrieta, José M.; Pardo, Rosa; Rodríguez-Bernal, Aníbal

    2015-12-01

    We analyze the asymptotic behavior of positive solutions of parabolic equations with a class of degenerate logistic nonlinearities of the type λu - n (x)uρ. An important characteristic of this work is that the region where the logistic term n (ṡ) vanishes, that is K0 = { x : n (x) = 0 }, may be non-smooth. We analyze conditions on λ, ρ, n (ṡ) and K0 guaranteeing that the solution starting at a positive initial condition remains bounded or blows up as time goes to infinity. The asymptotic behavior may not be the same in different parts of K0.

  19. Relativistic Bernstein waves in a degenerate plasma

    SciTech Connect

    Ali, Muddasir; Hussain, Azhar; Murtaza, G.

    2011-09-15

    Bernstein mode for a relativistic degenerate electron plasma is investigated. Using relativistic Vlasov-Maxwell equations, a general expression for the conductivity tensor is derived and then employing Fermi-Dirac distribution function a generalized dispersion relation for the Bernstein mode is obtained. Two limiting cases, i.e., non-relativistic and ultra-relativistic are discussed. The dispersion relations obtained are also graphically presented for some specific values of the parameters depicting how the propagation characteristics of Bernstein waves as well as the Upper Hybrid oscillations are modified with the increase in plasma number density.

  20. Family-Specific Degenerate Primer Design: A Tool to Design Consensus Degenerated Oligonucleotides

    PubMed Central

    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

  1. Cellular localization of dopamine D2 receptor messenger RNA in the rat trigeminal ganglion.

    PubMed

    Peterfreund, R A; Kosofsky, B E; Fink, J S

    1995-12-01

    The actions of dopamine are mediated by specific, high-affinity, G protein-coupled receptors. Multiple subtypes of dopamine receptors have been characterized, including the D2 subtype (D2R). Cells within the dorsal root and petrosal ganglia of the rat express D2R messenger RNA (mRNA) consistent with D2R expression by primary sensory neurons. We hypothesized that neurons of the trigeminal ganglion express D2R mRNA. Total cellular RNA from rat trigeminal ganglia was analyzed on Northern blots under high stringency conditions. Hybridization of trigeminal ganglion RNA resulted in a signal which comigrated with striatal, pituitary, and hypothalamic D2R mRNA. To determine the distribution of D2R expressing cells in the trigeminal ganglion, cryostat sections were analyzed by in situ hybridization followed by emulsion autoradiography. We identified a population of clustered cells labeled with dense grain concentrations over their cytoplasms. These findings demonstrate the expression of D2 dopamine receptor mRNA in discrete subpopulations of neurons in the rat trigeminal ganglion. Our observations suggest that drugs active at dopamine receptors of the D2 subtype are potential modulators of sensory activity of neurons whose cell bodies reside in the trigeminal ganglion. D2 dopamine receptors may thus have a role in clinical pain syndromes involving the head and neck. PMID:7486101

  2. Effects of aging and food restriction on the trigeminal ganglion: a morphometric study.

    PubMed

    Biedenbach, M A; Kalu, D N; Herbert, D C

    1992-09-01

    A quantitative morphometric study of the rat trigeminal ganglion was conducted to determine the changes that occur with aging. All measurements were tracked from young to old age in two rat groups simultaneously. One group was fed ad libitum, the other was maintained on restricted food intake from 6 weeks on. Immunocytochemical and radioimmunoassay techniques were used to study the neuron group that produces the peptide, CGRP and to compare it with the CGRP-negative neuron group. We observed that in the trigeminal ganglion, soma diameters and nucleus diameters of all neurons, whether CGRP positive or negative, increased modestly with age; so did total ganglion weight. Food restriction delayed, but did not prevent the increases in neuron diameters. No significant changes occurred as a function of age in the total number of neurons per ganglion, the ratio of CGRP positive to CGRP negative neurons and ganglion content of CGRP. Food restriction did not affect the parameters that remained constant with age. These findings are in contrast to the marked inhibitory effect of food restriction on age-related increase in thyroid calcitonin, a hormone that is encoded by the same gene as CGRP. PMID:1434941

  3. Angioarchitecture of the coeliac sympathetic ganglion complex in the common tree shrew (Tupaia glis)

    PubMed Central

    PROMWIKORN, WARAPORN; THONGPILA, SAKPORN; PRADIDARCHEEP, WISUIT; MINGSAKUL, THAWORN; CHUNHABUNDIT, PANJIT; SOMANA, REON

    1998-01-01

    The angioarchitecture of the coeliac sympathetic ganglion complex (CGC) of the common tree shrew (Tupaia glis) was studied by the vascular corrosion cast technique in conjunction with scanning electron microscopy. The CGC of the tree shrew was found to be a highly vascularised organ. It normally received arterial blood supply from branches of the inferior phrenic, superior suprarenal and inferior suprarenal arteries and of the abdominal aorta. In some animals, its blood supply was also derived from branches of the middle suprarenal arteries, coeliac artery, superior mesenteric artery and lumbar arteries. These arteries penetrated the ganglion at variable points and in slightly different patterns. They gave off peripheral branches to form a subcapsular capillary plexus while their main trunks traversed deeply into the inner part before branching into the densely packed intraganglionic capillary networks. The capillaries merged to form venules before draining into collecting veins at the peripheral region of the ganglion complex. Finally, the veins coursed to the dorsal aspect of the ganglion to drain into the renal and inferior phrenic veins and the inferior vena cava. The capillaries on the coeliac ganglion complex do not possess fenestrations. PMID:9877296

  4. An efficient method that reveals both the dendrites and the soma mosaics of retinal ganglion cells.

    PubMed

    Zhan, X J; Troy, J B

    1997-03-01

    A method of using neurobiotin to stain both the dendrites and the soma mosaics of retinal ganglion cells in fresh retinae is described. This method is simple to use and efficient in revealing morphological details for a large number of retinal ganglion cells. It has five advantages over currently available staining methods. (1) It stains all ganglion cells in the whole retina or in a selected retinal area, permitting ganglion cell distributions across the retina to be obtained. (2) It reveals cell dendrites in great detail, especially in regions outside the area centralis. The dendritic field mosaics and, therefore the dendritic field coverage factors, of different ganglion cell types across the whole retina can be obtained easily. (3) It works reliably, efficiently, and does not require the expensive set-up or the pains-taking work needed when staining cells through intracellular injection. (4) It works under both in vivo and in vitro settings, permitting the use of retinae from animals sacrificed for other purposes and the use of postmortem human retinae. (5) The end product of the visualization process is optically dark and electron dense, permitting specimens to be examined under both light and electron microscopes. PMID:9128174

  5. Spiral ganglion outgrowth and hearing development in p75-deficient mice.

    PubMed

    Brors, Dominik; Hansen, Stefan; Mlynski, Robert; Volkenstein, Stefan; Aletsee, Christoph; Sendtner, Michael; Ryan, Allen F; Dazert, Stefan

    2008-01-01

    To explore the role of nerve growth factor receptor p75(NTR) during the terminal neuronal development of the mammalian cochlea the onset of hearing and the in vitro response of spiral ganglion neurites to neurotrophin 3 (NT-3), which is known to play a critical role during neonatal inner ear development, were investigated in p75(NTR)-deficient mice (p75(NTR)-/-). Auditory-evoked brain stem response recordings from p75(NTR)-/- and wild-type (WT) littermates were measured from postnatal days (PD) 8 to 23. Additionally, spiral ganglion explants from p75(NTR)-/- and WT animals were dissected and cultured in an organotypic tissue culture system. In both groups, spiral ganglion neurite outgrowth was analyzed with and without NT-3 supplementation. No significant differences in the onset of hearing of mutant mice compared to the WT mice were detected, and both groups showed a similar development of hearing until PD 23. After stimulation with NT-3, neurite outgrowth was enhanced in both p75(NTR)-/- and WT mice. However, neurites from p75(NTR)-/- spiral ganglion explants were longer in both culture conditions. Moreover, NT-3 did not significantly enhance neurite number in p75(NTR)-/-, as it did in WT mice. P75(NTR) has a remarkable influence on spiral ganglion neurite growth behavior. However, p75(NTR) does not seem to be essential for the development of basic hearing function in the first 3 postnatal weeks. PMID:18663291

  6. MRI and MR tractography in bilateral hypertrophic olivary degeneration

    PubMed Central

    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. PMID:25489133

  7. Melatonin modulates M4-type ganglion-cell photoreceptors.

    PubMed

    Pack, W; Hill, D D; Wong, K Y

    2015-09-10

    In the retina, melatonin is secreted at night by rod/cone photoreceptors and serves as a dark-adaptive signal. Melatonin receptors have been found in many retinal neurons including melanopsin-containing intrinsically photosensitive retinal ganglion cells (ipRGCs), suggesting it could modulate the physiology of these inner retinal photoreceptors. Here, we investigated whether melatonin modulates the alpha-like M4-type ipRGCs, which are believed to mediate image-forming vision as well as non-image-forming photoresponses. Applying melatonin during daytime (when endogenous melatonin secretion is low) caused whole-cell-recorded M4 cells' rod/cone-driven depolarizing photoresponses to become broader and larger, whereas the associated elevation in spike rate was reduced. Melanopsin-based light responses were not affected significantly. Nighttime application of the melatonin receptor antagonist luzindole also altered M4 cells' rod/cone-driven light responses but in the opposite ways: the duration and amplitude of the graded depolarization were reduced, whereas the accompanying spiking increase was enhanced. These luzindole-induced changes confirmed that M4 cells are modulated by endogenous melatonin. Melatonin could induce the above effects by acting directly on M4 cells because immunohistochemistry detected MT1 receptors in these cells, although it could also act presynaptically. Interestingly, the daytime and nighttime recordings showed significant differences in resting membrane potential, spontaneous spike rate and rod/cone-driven light responses, suggesting that M4 cells are under circadian control. This is the first report of a circadian variation in ipRGCs' resting properties and synaptic input, and of melatoninergic modulation of ipRGCs. PMID:26141846

  8. Responses of rat trigeminal ganglion neurons to longitudinal whisker stimulation.

    PubMed

    Stüttgen, Maik C; Kullmann, Stephanie; Schwarz, Cornelius

    2008-10-01

    Responses of rat trigeminal ganglion neurons to longitudinal whisker stimulation. Rats use their mobile set of whiskers to actively explore their environment. Parameters that play a role to generate movement dynamics of the whisker shaft within the follicle, thus activating primary afferents, are manifold: among them are mechanical properties of the whiskers (curvature, elasticity and taper), active movements (head, body, and whiskers), and finally, object characteristics (surface, geometry, position, and orientation). Hence the whisker system is confronted with forces along all three axes in space. Movements along the two latitudinal axes of the whisker (horizontal and vertical) have been well studied. Here we focus on movement along the whisker's longitudinal axis that has been neglected so far. We employed ramp-and-hold movements that pushed the whisker shaft toward the skin and quantified the resulting activity in trigeminal first-order afferents in anesthetized rats. Virtually all recorded neurons were highly sensitive to longitudinal movement. Neurons could be perfectly segregated into two groups according to their modulation by stimulus amplitude and velocity, respectively. This classification regimen correlated perfectly with the presence or absence of slowly adapting responses in longitudinal stimulation but agreed with classification derived from latitudinal stimulation only if the whisker was engaged in its optimal direction and set point. We conclude that longitudinal stimulation is an extremely effective means to activate the tactile pathway and thus is highly likely to play an important role in tactile coding on the ascending somatosensory pathway. In addition, compared with latitudinal stimulation, it provides a reliable and easy to use method to classify trigeminal first-order afferents. PMID:18684907

  9. Calcium preconditioning triggers neuroprotection in retinal ganglion cells

    PubMed Central

    Brandt, Sean K.; Weatherly, Monique E.; Ware, Lillian; Linn, David M.; Linn, Cindy L.

    2010-01-01

    In the mammalian retina, excitotoxicity has been shown to be involved in apoptotic retinal ganglion cell (RGC) death and is associated with certain retinal disease states including glaucoma, diabetic retinopathy and retinal ischemia. Previous studies from this lab (Wehrwein et al., 2004) have demonstrated that acetylcholine (ACh) and nicotine protects against glutamate-induced excitotoxicity in isolated adult pig RGCs through nicotinic acetylcholine receptors (nAChRs). Activation of nAChRs in these RGCs triggers cell survival signaling pathways and inhibits apoptotic enzymes (Asomugha et al., 2010). However, the link between binding of nAChRs and activation of neuroprotective pathways is unknown. In this study, we examine the hypothesis that calcium permeation through nAChR channels is required for ACh-induced neuroprotection against glutamate-induced excitotoxicity in isolated pig RGCs. RGCs were isolated from other retinal tissue using a two step panning technique and cultured for 3 days under different conditions. In some studies, calcium imaging experiments were performed using the fluorescent calcium indicator, fluo-4, and demonstrated that calcium permeates the nAChR channels located on pig RGCs. In other studies, the extracellular calcium concentration was altered to determine the effect on nicotine-induced neuroprotection. Results support the hypothesis that calcium is required for nicotine-induced neuroprotection in isolated pig RGCs. Lastly, studies were performed to analyze the effects of preconditioning on glutamate-induced excitotoxicity and neuroprotection. In these studies, a preconditioning dose of calcium was introduced to cells using a variety of mechanisms before a large glutamate insult was applied to cells. Results from these studies support the hypothesis that preconditioning cells with a relatively low level of calcium before an excitotoxic insult leads to neuroprotection. In the future, these results could provide important information

  10. Sphenopalatine ganglion stimulation for the treatment of cluster headache

    PubMed Central

    Puche, Miguel; Garcia, Ana; Gascón, Francisco

    2014-01-01

    Cluster headache is a severe, debilitating disorder with pain that ranks among the most severe known to humans. Patients with cluster headaches have few therapeutic options and further, 10–20% develop drug-resistant attacks. The often brief duration of cluster attacks makes abortive therapy a challenge, and preventive medications are almost always provided to patients, but the side effects of these preventive medications can be significant. The sphenopalatine ganglion (SPG) is believed to play a role in headache pain and cranial autonomic symptoms associated with cluster headache, which is a result of activation of the trigeminal-autonomic reflex. For over 100 years, the SPG has been a clinical target to treat primary headache disorders using pharmacologic and nonpharmacologic methods. Radiofrequency lesioning and nerve-resection therapies, while initially beneficial, are irreversible procedures, and the use of neurostimulation provides one method of interfacing with the neural pathways without causing permanent damage to neural tissue. SPG neurostimulation is both reversible and adjustable, and has recently been tested in both proof-of-concept work and in a randomized, sham-controlled trial for the treatment of cluster headache. A randomized, sham-controlled study of 32 patients was performed to evaluate further the use of SPG stimulation for the acute treatment of chronic cluster headache. Of the 32 patients, 28 completed the randomized experimental period. Overall, 68% of patients experienced an acute response, a frequency response, or both. In this study the majority of adverse events were related to the implantation procedure, which typically resolved or remained mild in nature at 3 months following the implant procedure. This and other studies highlight the promise of using SPG stimulation to treat the pain-associated cluster headache. SPG stimulation could be a safe and effective option for chronic cluster headache. PMID:24790646

  11. Tetrandrine protects mouse retinal ganglion cells from ischemic injury

    PubMed Central

    Li, Weiyi; Yang, Chen; Lu, Jing; Huang, Ping; Barnstable, Colin J; Zhang, Chun; Zhang, Samuel S

    2014-01-01

    This study aimed to determine the protective effects of tetrandrine (Tet) on murine ischemia-injured retinal ganglion cells (RGCs). For this, we used serum deprivation cell model, glutamate and hydrogen peroxide (H2O2)-induced RGC-5 cell death models, and staurosporine-differentiated neuron-like RGC-5 in vitro. We also investigated cell survival of purified primary-cultured RGCs treated with Tet. An in vivo retinal ischemia/reperfusion model was used to examine RGC survival after Tet administration 1 day before ischemia. We found that Tet affected RGC-5 survival in a dose- and time-dependent manner. Compared to dimethyl sulfoxide treatment, Tet increased the numbers of RGC-5 cells by 30% at 72 hours. After 48 hours, Tet protected staurosporine-induced RGC-5 cells from serum deprivation-induced cell death and significantly increased the relative number of cells cultured with 1 mM H2O2 (P<0.01). Several concentrations of Tet significantly prevented 25-mM-glutamate-induced cell death in a dose-dependent manner. Tet also increased primary RGC survival after 72 and 96 hours. Tet administration (10 μM, 2 μL) 1 day before retinal ischemia showed RGC layer loss (greater survival), which was less than those in groups with phosphate-buffered saline intravitreal injection plus ischemia in the central (P=0.005, n=6), middle (P=0.018, n=6), and peripheral (P=0.017, n=6) parts of the retina. Thus, Tet conferred protective effects on serum deprivation models of staurosporine-differentiated neuron-like RGC-5 cells and primary cultured murine RGCs. Furthermore, Tet showed greater in vivo protective effects on RGCs 1 day after ischemia. Tet and ciliary neurotrophic factor maintained the mitochondrial transmembrane potential (ΔΨm) of primary cultured RGCs and inhibited the expression of activated caspase-3 and bcl-2 in ischemia/reperfusion-insult retinas. PMID:24711693

  12. Nodular fasciitis with degeneration and regression.

    PubMed

    Yanagisawa, Akihiro; Okada, Hideki

    2008-07-01

    Nodular fasciitis is a benign reactive proliferation that is frequently misdiagnosed as a sarcoma. This article describes a case of nodular fasciitis of 6-month duration located in the cheek, which degenerated and spontaneously regressed after biopsy. The nodule was fixed to the zygoma but was free from the overlying skin. The mass was 3.0 cm in diameter and demonstrated high signal intensity on T2-weighted magnetic resonance imaging. A small part of the lesion was biopsied. Pathological and immunohistochemical examinations identified the nodule as nodular fasciitis with myxoid histology. One month after the biopsy, the mass showed decreased signal intensity on T2-weighted images and measured 2.2 cm in size. The signal on T2-weighted images showed time-dependent decreases, and the mass continued to reduce in size throughout the follow-up period. The lesion presented as hypointense to the surrounding muscles on T2-weighted images and was 0.4 cm in size at 2 years of follow-up. This case demonstrates that nodular fasciitis with myxoid histology can change to that with fibrous appearance gradually with time, thus bringing about spontaneous regression. Degeneration may be involved in the spontaneous regression of nodular fasciitis with myxoid appearance. The mechanism of regression, unclarified at present, should be further studied. PMID:18650753

  13. Progressive retinal degeneration in ranch mink.

    PubMed

    Hadlow, W J

    1984-01-01

    Retinal degeneration was prevalent in a large group of sapphire and pastel mink (Mustela vison) kept for studies on slow viral diseases. Nearly 78% of those two to eight years old were affected. The retinopathy was equally common in both sexes but more frequent in sapphires (85%) than in pastels (63%), and it was severe more often in sapphires than in pastels. By light microscopy, the primary change appeared to be progressive degeneration of fully developed photoreceptors, beginning in their outer segments. In many mink, including some younger ones, the rods and cones and outer nuclear layer had disappeared from all but the far periphery of the fundus. The inner retinal layers were spared until late in the disease, and the pigment epithelium remained essentially unchanged. The cause of the retinopathy was not established. It may represent an abiotrophy in which the structural integrity of the photoreceptors began to wane in many mink after they reached two years of age. Apart from reducing visual acuity, the retinopathy has implications for the photoperiodic control of fur growth and reproduction in this highly light-sensitive carnivore. PMID:6710807

  14. Metabolic anatomy of paraneoplastic cerebellar degeneration

    SciTech Connect

    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.

  15. Degenerate parametric oscillation in quantum membrane optomechanics

    NASA Astrophysics Data System (ADS)

    Benito, Mónica; Sánchez Muñoz, Carlos; Navarrete-Benlloch, Carlos

    2016-02-01

    The promise of innovative applications has triggered the development of many modern technologies capable of exploiting quantum effects. But in addition to future applications, such quantum technologies have already provided us with the possibility of accessing quantum-mechanical scenarios that seemed unreachable just a few decades ago. With this spirit, in this work we show that modern optomechanical setups are mature enough to implement one of the most elusive models in the field of open system dynamics: degenerate parametric oscillation. Introduced in the eighties and motivated by its alleged implementability in nonlinear optical resonators, it rapidly became a paradigm for the study of dissipative phase transitions whose corresponding spontaneously broken symmetry is discrete. However, it was found that the intrinsic multimode nature of optical cavities makes it impossible to experimentally study the model all the way through its phase transition. In contrast, here we show that this long-awaited model can be implemented in the motion of a mechanical object dispersively coupled to the light contained in a cavity, when the latter is properly driven with multichromatic laser light. We focus on membranes as the mechanical element, showing that the main signatures of the degenerate parametric oscillation model can be studied in state-of-the-art setups, thus opening the possibility of analyzing spontaneous symmetry breaking and enhanced metrology in one of the cleanest dissipative phase transitions. In addition, the ideas put forward in this work would allow for the dissipative preparation of squeezed mechanical states.

  16. Monte Carlo methods for localization of cones given multielectrode retinal ganglion cell recordings.

    PubMed

    Sadeghi, K; Gauthier, J L; Field, G D; Greschner, M; Agne, M; Chichilnisky, E J; Paninski, L

    2013-01-01

    It has recently become possible to identify cone photoreceptors in primate retina from multi-electrode recordings of ganglion cell spiking driven by visual stimuli of sufficiently high spatial resolution. In this paper we present a statistical approach to the problem of identifying the number, locations, and color types of the cones observed in this type of experiment. We develop an adaptive Markov Chain Monte Carlo (MCMC) method that explores the space of cone configurations, using a Linear-Nonlinear-Poisson (LNP) encoding model of ganglion cell spiking output, while analytically integrating out the functional weights between cones and ganglion cells. This method provides information about our posterior certainty about the inferred cone properties, and additionally leads to improvements in both the speed and quality of the inferred cone maps, compared to earlier "greedy" computational approaches. PMID:23194406

  17. The C2 ganglion sectioning epidural approach to craniocervical junction chordoma: a technical case report.

    PubMed

    Hagihara, Naoshi; Matsushima, Toshio; Kawashima, Masatou; Hikita, Takashi

    2012-01-01

    In chordoma, complete surgical removal of the epidural tumor should be the first choice of treatment. Numerous surgical approaches to clival chordoma have been described: anterior approaches, lateral approaches, and posterolateral approaches. A multistaged operation with a combination of these approaches is generally performed. We used three approaches to remove a clival chordoma extending from the lower clivus anteriorly to the anterior perivertebral space and inferiorly to the C2 level. The epidural posterolateral approach through the vertebral artery (VA)-C2 interval space after resection of the C2 dorsal ganglion was the most effective. To our knowledge, the epidural posterolateral approach below VA, referred to as C2 ganglion sectioning epidural approach has not been reported as an independent approach in detail. We report a two-year-old girl with a lower clival chordoma which has been excised using C2 ganglion sectioning epidural approach. PMID:23287329

  18. Ganglion cyst of the cervical spine presenting with Brown-Sequard syndrome.

    PubMed

    Cheng, Wen-Yu; Shen, Chiung-Chyi; Wen, Mei-Chin

    2006-12-01

    Ganglion cysts of the spine are uncommon. They occur mostly in the dorsolateral trunk and arise with the greatest frequency in the lumbar spine. However, they are rarely symptomatic. We report a rare case of a patient with a ganglion cyst of the lower cervical spine presenting with acute Brown-Sequard syndrome. The patient had no history of trauma. Magnetic resonance imaging of the cervical spine showed a cystic lesion connecting to the synovial joint C6-7 and compressing the posterior aspect of the spinal cord. The patient underwent emergent C6-7 laminectomy with total removal of the cyst. Neurological function recovered completely 4 months after operation. Ganglion cysts should be considered in the differential diagnosis of an extradural mass of the cervical spine. Magnetic resonance imaging provides a rapid and correct diagnosis, and laminectomy with removal of the cyst results in good neurological recovery. PMID:17113987

  19. Retinal ganglion cells are autonomous circadian oscillators synthesizing N-acetylserotonin during the day.

    PubMed

    Garbarino-Pico, Eduardo; Carpentieri, Agata R; Contin, Maria A; Sarmiento, María I Keller; Brocco, Marcela A; Panzetta, Pedro; Rosenstein, Ruth E; Caputto, Beatriz L; Guido, Mario E

    2004-12-01

    Retinal ganglion cells send visual and circadian information to the brain regarding the environmental light-dark cycles. We investigated the capability of retinal ganglion cells of synthesizing melatonin, a highly reliable circadian marker that regulates retinal physiology, as well as the capacity of these cells to function as autonomous circadian oscillators. Chick retinal ganglion cells presented higher levels of melatonin assessed by radioimmunoassay during both the subjective day in constant darkness and the light phase of a light-dark cycle. Similar changes were observed in mRNA levels and activity of arylalkylamine N-acetyltransferase, a key enzyme in melatonin biosynthesis, with the highest levels of both parameters during the subjective day. These daily variations were preceded by the elevation of cyclic-AMP content, the second messenger involved in the regulation of melatonin biosynthesis. Moreover, cultures of immunopurified retinal ganglion cells at embryonic day 8 synchronized by medium exchange synthesized a [3H]melatonin-like indole from [3H]tryptophan. This [3H]indole was rapidly released to the culture medium and exhibited a daily variation, with levels peaking 8 h after synchronization, which declined a few hours later. Cultures of embryonic retinal ganglion cells also showed self-sustained daily rhythms in arylalkylamine N-acetyltransferase mRNA expression during at least three cycles with a period near 24 h. These rhythms were also observed after the application of glutamate. The results demonstrate that chick retinal ganglion cells may function as autonomous circadian oscillators synthesizing a melatonin-like indole during the day. PMID:15448149

  20. Processing of central and reflex vagal drives by rat cardiac ganglion neurones: an intracellular analysis.

    PubMed

    McAllen, Robin M; Salo, Lauren M; Paton, Julian F R; Pickering, Anthony E

    2011-12-01

    Cardiac vagal tone is an important indicator of cardiovascular health, and its loss is an independent risk factor for arrhythmias and mortality. Several studies suggest that this loss of vagal tone can occur at the cardiac ganglion but the factors affecting ganglionic transmission in vivo are poorly understood. We have employed a novel approach allowing intracellular recordings from functionally connected cardiac vagal ganglion cells in the working heart-brainstem preparation. The atria were stabilised in situ preserving their central neural connections, and ganglion cells (n = 32) were impaled with sharp microelectrodes. Cardiac ganglion cells with vagal synaptic inputs (spontaneous, n = 10; or electrically evoked from the vagus, n = 3) were identified as principal neurones and showed tonic firing responses to current injected to their somata. Cells lacking vagal inputs (n = 19, presumed interneurones) were quiescent but showed phasic firing responses to depolarising current. In principal cells the ongoing action potentials and EPSPs exhibited respiratory modulation, with peak frequency in post-inspiration. Action potentials arose from unitary EPSPs and autocorrelation of those events showed that each ganglion cell received inputs from a single active preganglionic source. Peripheral chemoreceptor, arterial baroreceptor and diving response activation all evoked high frequency synaptic barrages in these cells, always from the same single preganglionic source. EPSP amplitudes showed frequency dependent depression, leading to more spike failures at shorter inter-event intervals. These findings indicate that rather than integrating convergent inputs, cardiac vagal postganglionic neurones gate preganglionic inputs, so regulating the proportion of central parasympathetic tone that is transmitted on to the heart. PMID:22005679

  1. Epoxyeicosatrienoic Acids (EETs) are Endogenous Regulators of Vasoactive Neuropeptide Release from Trigeminal Ganglion Neurons

    PubMed Central

    Iliff, Jeffrey J.; Fairbanks, Stacy L.; Balkowiec, Agnieszka; Alkayed, Nabil J.

    2010-01-01

    Epoxyeicosatrienoic acids (EETs) are bioactive eicosanoids produced from arachidonic acid by cytochrome P450 epoxygenases. We previously described the expression of CYP-2J epoxygenase in rat trigeminal ganglion neurons and that EETs signaling is involved in cerebrovascular dilation resulting from perivascular nerve stimulation. Herein we evaluate the presence of the EETs signaling pathway in trigeminal ganglion neurons and their role in modulating the release of calcitonin gene-related peptide (CGRP) by trigeminal ganglion neurons. Liquid chromatography tandem mass spectrometry identified the presence of each of the four EETs regio-isomers within primary trigeminal ganglion neurons. Stimulation for one hour with the transient receptor potential vanilloid-1 channel agonist capsaicin (100 nmol/L) or depolarizing K+ (60 mmol/L) increased CGRP release as measured by ELISA. Stimulation-evoked CGRP release was attenuated by 30 min pre-treatment with the EETs antagonist 14,15-epoxyeicosa-5(Z)-enoic acid (14,15-EEZE, 10 μmol/L). K+ stimulation elevated CGRP release 2.9 ± 0.3-fold above control levels, while in the presence of 14,15-EEZE K+-evoked CGRP release was significantly reduced to 1.1 ± 0.2-fold above control release (p<0.01 ANOVA, n=6). 14,15-EEZE likewise attenuated capsaicin-evoked CGRP release from trigeminal ganglion neurons (p<0.05 ANOVA, n=6). Similarly, pre-treatment with the CYP epoxygenase inhibitor attenuated stimulation-evoked CGRP release. These data demonstrate that EETs are endogenous constituents of rat trigeminal ganglion neurons and suggest that they may act as intracellular regulators of neuropeptide release, which may have important clinical implications for treatment of migraine, stroke and vasospasm after subarachnoid hemorrhage. PMID:20950340

  2. Epoxyeicosatrienoic acids are endogenous regulators of vasoactive neuropeptide release from trigeminal ganglion neurons.

    PubMed

    Iliff, Jeffrey J; Fairbanks, Stacy L; Balkowiec, Agnieszka; Alkayed, Nabil J

    2010-12-01

    Epoxyeicosatrienoic acids (EETs) are bioactive eicosanoids produced from arachidonic acid by cytochrome P450 epoxygenases. We previously described the expression of cytochrome P450-2J epoxygenase in rat trigeminal ganglion neurons and that EETs signaling is involved in cerebrovascular dilation resulting from perivascular nerve stimulation. In this study, we evaluate the presence of the EETs signaling pathway in trigeminal ganglion neurons and their role in modulating the release of calcitonin gene-related peptide (CGRP) by trigeminal ganglion neurons. Liquid chromatography tandem mass spectrometry identified the presence of each of the four EETs regio-isomers within primary trigeminal ganglion neurons. Stimulation for 1 h with the transient receptor potential vanilloid-1 channel agonist capsaicin (100 nmol/L) or depolarizing K(+) (60 mmol/L) increased CGRP release as measured by ELISA. Stimulation-evoked CGRP release was attenuated by 30 min pre-treatment with the EETs antagonist 14,15-epoxyeicosa-5(Z)-enoic acid (14,15-EEZE, 10 μmol/L). K(+) stimulation elevated CGRP release 2.9 ± 0.3-fold above control levels, whereas in the presence of 14,15-EEZE K(+)-evoked CGRP release was significantly reduced to 1.1 ± 0.2-fold above control release (p < 0.01 anova, n = 6). 14,15-EEZE likewise attenuated capsaicin-evoked CGRP release from trigeminal ganglion neurons (p < 0.05 anova, n = 6). Similarly, pre-treatment with the cytochrome P450 epoxygenase inhibitor attenuated stimulation-evoked CGRP release. These data demonstrate that EETs are endogenous constituents of rat trigeminal ganglion neurons and suggest that they may act as intracellular regulators of neuropeptide release, which may have important clinical implications for treatment of migraine, stroke and vasospasm after subarachnoid hemorrhage. PMID:20950340

  3. Evidence for a novel regulatory pathway for herpes simplex virus gene expression in trigeminal ganglion neurons.

    PubMed Central

    Kosz-Vnenchak, M; Jacobson, J; Coen, D M; Knipe, D M

    1993-01-01

    Thymidine kinase (TK)-negative (TK-) mutant strains of herpes simplex virus type 1 (HSV-1) show reduced expression of alpha and beta viral genes during acute infection of trigeminal ganglion neurons following corneal infection (M. Kosz-Vnenchak, D. M. Coen, and D. M. Knipe, J. Virol. 64:5396-5402, 1990). It was surprising that a defect in a beta gene product would lead to decreased alpha and beta gene expression, given the regulatory pathways demonstrated for HSV infection of cultured cells. In this study, we have examined viral gene expression during reactivation from latent infection in explanted trigeminal ganglion tissue. In explant reactivation studies with wild-type virus, we observed viral productive gene expression over the first 48 h of explant incubation occurring in a temporal order (alpha, beta, gamma) similar to that in cultured cells. This occurred predominantly in latency-associated transcript-positive neurons but was limited to a fraction of these cells. In contrast, TK- mutant viruses showed greatly reduced alpha and beta gene expression upon explant of latently infected trigeminal ganglion tissue. An inhibitor of viral TK or an inhibitor of viral DNA polymerase greatly decreased viral lytic gene expression in trigeminal ganglion tissue latently infected with wild-type virus and explanted in culture. These results indicate that the regulatory mechanisms governing HSV gene expression are different in trigeminal ganglion neurons and cultured cells. We present a new model for viral gene expression in trigeminal ganglion neurons with implications for the nature of the decision process between latent infection and productive infection by HSV. Images PMID:8394454

  4. Restoration of visual function by expression of a light-gated mammalian ion channel in retinal ganglion cells or ON-bipolar cells.

    PubMed

    Gaub, Benjamin M; Berry, Michael H; Holt, Amy E; Reiner, Andreas; Kienzler, Michael A; Dolgova, Natalia; Nikonov, Sergei; Aguirre, Gustavo D; Beltran, William A; Flannery, John G; Isacoff, Ehud Y

    2014-12-23

    Most inherited forms of blindness are caused by mutations that lead to photoreceptor cell death but spare second- and third-order retinal neurons. Expression of the light-gated excitatory mammalian ion channel light-gated ionotropic glutamate receptor (LiGluR) in retinal ganglion cells (RGCs) of the retina degeneration (rd1) mouse model of blindness was previously shown to restore some visual functions when stimulated by UV light. Here, we report restored retinal function in visible light in rodent and canine models of blindness through the use of a second-generation photoswitch for LiGluR, maleimide-azobenzene-glutamate 0 with peak efficiency at 460 nm (MAG0(460)). In the blind rd1 mouse, multielectrode array recordings of retinal explants revealed robust and uniform light-evoked firing when LiGluR-MAG0(460) was targeted to RGCs and robust but diverse activity patterns in RGCs when LiGluR-MAG0(460) was targeted to ON-bipolar cells (ON-BCs). LiGluR-MAG0(460) in either RGCs or ON-BCs of the rd1 mouse reinstated innate light-avoidance behavior and enabled mice to distinguish between different temporal patterns of light in an associative learning task. In the rod-cone dystrophy dog model of blindness, LiGluR-MAG0(460) in RGCs restored robust light responses to retinal explants and intravitreal delivery of LiGluR and MAG0(460) was well tolerated in vivo. The results in both large and small animal models of photoreceptor degeneration provide a path to clinical translation. PMID:25489083

  5. Restoration of visual function by expression of a light-gated mammalian ion channel in retinal ganglion cells or ON-bipolar cells

    PubMed Central

    Gaub, Benjamin M.; Berry, Michael H.; Holt, Amy E.; Reiner, Andreas; Kienzler, Michael A.; Dolgova, Natalia; Nikonov, Sergei; Aguirre, Gustavo D.; Beltran, William A.; Flannery, John G.; Isacoff, Ehud Y.

    2014-01-01

    Most inherited forms of blindness are caused by mutations that lead to photoreceptor cell death but spare second- and third-order retinal neurons. Expression of the light-gated excitatory mammalian ion channel light-gated ionotropic glutamate receptor (LiGluR) in retinal ganglion cells (RGCs) of the retina degeneration (rd1) mouse model of blindness was previously shown to restore some visual functions when stimulated by UV light. Here, we report restored retinal function in visible light in rodent and canine models of blindness through the use of a second-generation photoswitch for LiGluR, maleimide-azobenzene-glutamate 0 with peak efficiency at 460 nm (MAG0460). In the blind rd1 mouse, multielectrode array recordings of retinal explants revealed robust and uniform light-evoked firing when LiGluR-MAG0460 was targeted to RGCs and robust but diverse activity patterns in RGCs when LiGluR-MAG0460 was targeted to ON-bipolar cells (ON-BCs). LiGluR-MAG0460 in either RGCs or ON-BCs of the rd1 mouse reinstated innate light-avoidance behavior and enabled mice to distinguish between different temporal patterns of light in an associative learning task. In the rod-cone dystrophy dog model of blindness, LiGluR-MAG0460 in RGCs restored robust light responses to retinal explants and intravitreal delivery of LiGluR and MAG0460 was well tolerated in vivo. The results in both large and small animal models of photoreceptor degeneration provide a path to clinical translation. PMID:25489083

  6. The relation between resolution measurements and numbers of retinal ganglion cells in the same human subjects.

    PubMed

    Popovic, Zoran; Sjöstrand, Johan

    2005-08-01

    Limiting factors of resolution have previously only been investigated by using resolution data and retinal ganglion cell spacing data from different individuals. We report on our unique opportunity to study the intra-individual relationship in three human subjects between retinal ganglion cell separations and resolution thresholds, measured with high-pass resolution perimetry. Our data show that resolution is directly proportional to half the midget population, in accordance with the hypothesis that a dichotomous midget ON/OFF population mediates resolution. PMID:15924946

  7. Correlation in the Discharges of Neighboring Rat Retinal Ganglion Cells During Prenatal Life

    NASA Astrophysics Data System (ADS)

    Maffei, Lamberto; Galli-Resta, Lucia

    1990-04-01

    The spontaneous discharges of neighboring retinal ganglion cells were recorded simultaneously in anesthetized prenatal rats between embryonic days 18 and 21. We report here that in the majority of cases the firings of neighboring retinal ganglion cells are strongly correlated during prenatal life. Correlation in the discharges of neighboring cells during development has long been suggested as a way to consolidate synaptic connections with a target cell onto which they converge, a model first proposed by Hebb. Correlation in the activities of neighboring neurons in the retina could be the basis of developmental processes such as refinement of retinotopic maps in the brain and segregation of the inputs from the two eyes.

  8. Ganglion cell topography of the retina in the bottlenosed dolphin, Tursiops truncatus.

    PubMed

    Mass, A M; Supin AYa

    1995-01-01

    The distribution and size of ganglion cells in the retina of the bottlenosed dolphin are described. Ganglion cells concentrate at two spots of the highest density in the nasal and temporal quadrants, 15 to 16 mm (50 to 55 degrees) from the optic disk. The mean peak cell density in both spots is about 670 cells/mm2. With a posterior nodal distance of 14.5 mm (under water), this corresponds to 43 cells/deg2, which provides a retinal resolution of about 9' in water and 12' in air. Mean cell size was from 26 to 31 microns in various parts of the retina. PMID:7620874

  9. Concurrent Lateral Dorsal Cutaneous and Deep Peroneal Intraneural Ganglion Cysts in the Foot.

    PubMed

    Prasad, Nikhil K; Amrami, Kimberly K; Jentoft, Mark E; Spinner, Robert J

    2016-01-01

    Intraneural ganglion cysts are non-neoplastic collections of mucinous material within the epineurium of peripheral nerves. We present a rare case of 2 intraneural ganglion cysts in separate nerves of the foot, originating from different joints within the same joint complex. Our findings add to the large body of evidence supporting the unifying articular (synovial) theory. We emphasize the importance of delineating the cyst morphology and origins using high-resolution magnetic resonance imaging before surgery and searching for and resecting the articular branch or branches during surgery. PMID:25979292

  10. Unusual location of a posttraumatic ganglion and rupture of the peroneus brevis tendon: a case report.

    PubMed

    Waldecker, Ute

    2005-01-01

    The typical location of a peroneus brevis tendon tear has been described at the posterior margin of the fibula due to an entrapment mechanism or repetitive anterior subluxation of the tendon. A case of a posttraumatic intratendinous ganglion of the peroneus brevis tendon in the distal third of the peroneus brevis is reported. The ganglion developed from a longitudinal tear in the tendon substance after an inversion ankle sprain. This case is reported because of the unusual location. The clinical course and surgical treatment is also discussed. PMID:15768368

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

    PubMed

    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. PMID:26045399

  12. Electroacupuncture in the treatment of a ganglion of the wrist--a case report.

    PubMed

    Tekeoğlu, Ibrahim; Doğan, Ali

    2006-03-01

    A ganglion is a cystic swelling that occurs most commonly in women. Recurrence is possible after conservative or surgical treatment. A novel method of therapy, electroacupuncture stimulation, was performed in a 53 year old woman with a large, recurrent dorsal wrist ganglion. After treatment it rapidly disappeared and there was no recurrence during the one year follow-up period. Although the mechanism is obscure, it is our impression that electroacupuncture may have a local action on such cysts in addition to needle drainage. PMID:16619407

  13. Chemical ablation of stellate ganglion for head and neck cancer pain.

    PubMed

    Ghai, A; Kaushik, T; Kumar, R; Wadhera, S

    2016-01-01

    We present a case of patient with orofacial cancer having pain on one side of face affecting her ability to speak, chew, swallow and sleep leading to emotional and behavioral deterioration. A diagnostic stellate ganglion block was performed followed by chemical neurolysis using phenol under ultrasound guidance, to prevent complications due to inadvertent spread of drug. Her pain scores decreased drastically, she was able to chew and swallow. Weighing the risk of permanent Horner's syndrome or motor paralysis with benefit of improvement in basic functioning of debilitated patients chemical neurolysis of stellate ganglion can be performed with advanced imaging modalities. PMID:27363209

  14. A Thy1-CFP DBA/2J mouse line with cyan fluorescent protein expression in retinal ganglion cells

    PubMed Central

    RAYMOND, IONA D.; POOL, ANGELA L.; VILA, ALEJANDRO; BRECHA, NICHOLAS C.

    2013-01-01

    A DBA/2J (D2) transgenic mouse line with cyan fluorescent protein (CFP) reporter expression in ganglion cells was developed for the analysis of ganglion cells during progressive glaucoma. The Thy1-CFP D2 (CFP-D2) line was created by congenically breeding the D2 line, which develops pigmentary glaucoma, and the Thy1-CFP line, which expresses CFP in ganglion cells. Microsatellite marker analysis of CFP-D2 progeny verified the genetic inclusion of the D2 isa and ipd loci. Specific mutations within these loci lead to dysfunctional melanosomal proteins and glaucomatous phenotype in D2 mice. Polymerase chain reaction analysis confirmed the inclusion of the Thy1-CFP transgene. CFP-fluorescent ganglion cells, 6–20 μm in diameter, were distributed in all retinal regions, CFP processes were throughout the inner plexiform layer, and CFP-fluorescent axons were in the fiber layer and optic nerve head. Immunohistochemistry with antibodies to ganglion cell markers NF-L, NeuN, Brn3a, and SMI32 was used to confirm CFP expression in ganglion cells. Immunohistochemistry with antibodies to amacrine cell markers HPC-1 and ChAT was used to confirm weak CFP expression in cholinergic amacrine cells. CFP-D2 mice developed a glaucomatous phenotype, including iris disease, ganglion cell loss, attrition of the fiber layer, and elevated intraocular pressure. A CFP-D2 transgenic line with CFP-expressing ganglion cells was developed, which has (1) a predominantly D2 genetic background, (2) CFP-expressing ganglion cells, and (3) age-related progressive glaucoma. This line will be of value for experimental studies investigating ganglion cells and their axons in vivo and in vitro during the progressive development of glaucoma. PMID:19930759

  15. Solitons in Degenerate Electron-Phonon Systems

    NASA Astrophysics Data System (ADS)

    Foell, Charles; Clougherty, Dennis

    2004-03-01

    We consider a 1øplus 1-dimensional model describing the coupling between degenerate electron states under local Jahn-Teller interactions. In the adiabatic approximation, the equations of motion are shown to reduce to a set of coupled non-linear Schrödinger equations in the electron fields. We demonstrate that in the continuum limit solitary waves of the wave-daughter wave type are stable for sufficiently strong on-site Coulomb repulsion. Our results may have relevance to describing the electronic and optical properties of quasi-one-dimensional systems such as halogen-bridged mixed-valence transition-metal linear-chain complexes (MX chains) and polymeric fullerides.

  16. Therapeutic interventions in parkinsonism: Corticobasal degeneration.

    PubMed

    Marsili, Luca; Suppa, Antonio; Berardelli, Alfredo; Colosimo, Carlo

    2016-01-01

    Corticobasal degeneration (CBD) is a progressive neurodegenerative disorder resulting from pathological accumulation of tau protein and is included in the spectrum of Atypical Parkinsonism. The typical clinical phenotype of CBD is characterized by the Corticobasal syndrome (CBS). In recent years it has become clear that the clinical picture of CBS may be caused by different pathological conditions, resulting in frequent misdiagnosis. CBD has high morbidity and poor prognosis with no effective therapies. In this review, we will discuss the symptomatic treatment, the palliative care and the disease modifying strategies currently in use. Symptomatic treatment in patients with CBD may sometimes be useful for improving motor (parkinsonism, dystonia and myoclonus) and non-motor (cognitive-behavioral) symptoms, but the effects are often unsatisfactory. In addition, non-pharmacological strategies and palliative care are useful integrating components of the multidisciplinary therapeutic approach for patients with CBD. Despite many efforts, a disease-modifying treatment is still unavailable for CBD. PMID:26382843

  17. A COMPUTATIONAL MODEL OF MOTOR NEURON DEGENERATION

    PubMed Central

    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

  18. Hypocoercivity of linear degenerately dissipative kinetic equations

    NASA Astrophysics Data System (ADS)

    Duan, Renjun

    2011-08-01

    In this paper we develop a general approach of studying the hypocoercivity for a class of linear kinetic equations with both transport and degenerately dissipative terms. As concrete examples, the relaxation operator, Fokker-Planck operator and linearized Boltzmann operator are considered when the spatial domain takes the whole space or torus and when there is a confining force or not. The key part of the developed approach is to construct some equivalent temporal energy functionals for obtaining time rates of the solution trending towards equilibrium in some Hilbert spaces. The result in the case of the linear Boltzmann equation with confining forces is new. The proof mainly makes use of the macro-micro decomposition combined with Kawashima's argument on dissipation of the hyperbolic-parabolic system. At the end, a Korn-type inequality with probability measure is provided to deal with dissipation of momentum components.

  19. [Epidemiology of age-related macular degeneration].

    PubMed

    Brandl, C; Stark, K J; Wintergerst, M; Heinemann, M; Heid, I M; Finger, R P

    2016-09-01

    Age-related macular degeneration (AMD) is the main cause of blindness in industrialized societies. Population-based epidemiological investigations generate important data on prevalence, incidence, risk factors, and future trends. This review summarizes the most important epidemiological studies on AMD with a focus on their transferability to Germany including existing evidence for the main risk factors for AMD development and progression. Future tasks, such as the standardization of grading systems and the use of recent retinal imaging technology in epidemiological studies are discussed. In Germany, epidemiological data on AMD are scarce. However, the need for epidemiological research in ophthalmology is currently being addressed by several recently started population-based studies. PMID:27541733

  20. MicroRNA in intervertebral disc degeneration.

    PubMed

    Li, Zheng; Yu, Xin; Shen, Jianxiong; Chan, Matthew T V; Wu, William Ka Kei

    2015-06-01

    Aetiology of intervertebral disc degeneration (IDD) is complex, with genetic, developmental, biochemical and biomechanical factors contributing to the disease process. It is becoming obvious that epigenetic processes influence evolution of IDD as strongly as the genetic background. Deregulated phenotypes of nucleus pulposus cells, including differentiation, migration, proliferation and apoptosis, are involved in all stages of progression of human IDD. Non-coding RNAs, including microRNAs, have recently been recognized as important regulators of gene expression. Research into roles of microRNAs in IDD has been very active over the past 5 years. Our review summarizes current research enlightenment towards understanding roles of microRNAs in regulating nucleus pulposus cell functions in IDD. These exciting findings support the notion that specific modulation of microRNAs may represent an attractive approach for management of IDD. PMID:25736871

  1. The muon g - 2 and degenerate supersymmetry

    NASA Astrophysics Data System (ADS)

    Chowdhury, Debtosh; Patel, Ketan M.; Tata, Xerxes; Vempati, Sudhir K.

    2016-04-01

    A degenerate supersymmetric particle spectrum can escape constraints from flavor physics and at the same time evade limits from the direct searches. If such a spectrum is light enough, it can also account for the observed value of the anomalous magnetic moment of the muon. Inspired by this, we consider a scenario where all the soft terms have approximately a common mass scale while allowing for small splittings. We study this scenario considering the constraints from Higgs mass, various B meson decays and the dark matter relic density. We find that, with superpartners ~ 800 - 1000 GeV, it is still possible to escape the present limits from the first run of LHC and flavor physics and can account for muon g - 2 within 2σ.

  2. Quantum Walk in Degenerate Spin Environments

    NASA Astrophysics Data System (ADS)

    Carlström, Johan; Prokof'ev, Nikolay; Svistunov, Boris

    2016-06-01

    We study the propagation of a hole in degenerate (paramagnetic) spin environments. This canonical problem has important connections to a number of physical systems, and is perfectly suited for experimental realization with ultracold atoms in an optical lattice. At the short-to-intermediate time scale that we can access using a stochastic-series-type numeric scheme, the propagation turns out to be distinctly nondiffusive with the probability distribution featuring minima in both space and time due to quantum interference, yet the motion is not ballistic, except at the beginning. We discuss possible scenarios for long-term evolution that could be explored with an unprecedented degree of detail in experiments with single-atom resolved imaging.

  3. Subwavelength total acoustic absorption with degenerate resonators

    NASA Astrophysics Data System (ADS)

    Yang, Min; Meng, Chong; Fu, Caixing; Li, Yong; Yang, Zhiyu; Sheng, Ping

    2015-09-01

    We report the experimental realization of perfect sound absorption by sub-wavelength monopole and dipole resonators that exhibit degenerate resonant frequencies. This is achieved through the destructive interference of two resonators' transmission responses, while the matching of their averaged impedances to that of air implies no backscattering, thereby leading to total absorption. Two examples, both using decorated membrane resonators (DMRs) as the basic units, are presented. The first is a flat panel comprising a DMR and a pair of coupled DMRs, while the second one is a ventilated short tube containing a DMR in conjunction with a sidewall DMR backed by a cavity. In both examples, near perfect absorption, up to 99.7%, has been observed with the airborne wavelength up to 1.2 m, which is at least an order of magnitude larger than the composite absorber. Excellent agreement between theory and experiment is obtained.

  4. Cartilage degeneration in different human joints.

    PubMed

    Kuettner, K E; Cole, A A

    2005-02-01

    Variations among joints in the initiation and progression of degeneration may be explained, in part, by metabolic, biochemical and biomechanical differences. Compared to the cartilage in the knee joint, ankle cartilage has a higher content of proteoglycans and water, as well as an increased rate of proteoglycan turnover and synthesis, all of which are responsible for its increased stiffness and reduced permeability. Chondrocytes within ankle cartilage have a decreased response to catabolic factors such as interleukin-1 and fibronectin fragments, compared to the chondrocytes of knee cartilage. Moreover, in response to damage, ankle chondrocytes synthesize proteoglycans at a higher rate than that found in knee cartilage chondrocytes, which suggests a greater capacity for repair. In addition to the cartilages of the two joints, the underlying bones also respond differently to degenerative changes. Taken together, these metabolic, biochemical and biomechanical differences may provide protection to the ankle. PMID:15694570

  5. Degenerate R-S perturbation theory

    NASA Technical Reports Server (NTRS)

    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.

  6. Spectroscopic temperature determination of degenerate Fermi gases

    SciTech Connect

    Kostrun, Marijan; Cote, Robin

    2003-12-01

    We suggest a simple method for measuring the temperature of ultracold gases made of fermions. We show that by using a two-photon Raman probe, it is possible to obtain line shapes which reveal properties of the degenerate sample, notably its temperature T. The proposed method could be used with identical fermions in different hyperfine states interacting via s-wave scattering or identical fermions in the same hyperfine state via p-wave scattering. We illustrate the applicability of the method in realistic conditions for {sup 6}Li prepared in two different hyperfine states. We find that temperatures down to 0.05T{sub F} can be determined by this in situ method.

  7. Age-related macular degeneration: current treatments

    PubMed Central

    Hubschman, Jean Pierre; Reddy, Shantan; Schwartz, Steven D

    2009-01-01

    Purpose: Although important progress has been made in understanding age-related macular degeneration (AMD), management of the disease continues to be a challenge. AMD research has led to a widening of available treatment options and improved prognostic perspectives. This essay reviews these treatment options. Design: Interpretative essay. Methods: Literature review and interpretation. Results: Current treatments to preserve vision in patients with non-exudative AMD include antioxidant vitamins and mineral supplementations. Exudative AMD is currently most often treated monthly with anti-VEGF intravitreal injections. However, investigators are beginning to experiment with combination therapy and surgical approaches in an attempt to limit the number of treatment and reduce the financial burden on the health care system. Conclusion: By better understanding the basis and pathogenesis of AMD, newer therapies will continue to be developed that target specific pathways in patients with AMD, with the hoped for outcome of better management of the disease and improved visual acuity. PMID:19668560

  8. Topological superradiance in a degenerate Fermi gas

    NASA Astrophysics Data System (ADS)

    Pan, Jian-Song; Liu, Xiong-Jun; Zhang, Wei; Yi, Wei; Guo, Guang-Can; Yi's Group Team; Liu's Group Team; Zhang's Group Team

    2015-05-01

    We predict the existence of a topological superradiant state in a two-component degenerate Fermi gas in a cavity. The superradiant light generation in the transversely driven cavity mode induces a cavity-assisted spin-orbit coupling in the system and opens a bulk gap at half filling. This mechanism can simultaneously drive a topological phase transition in the system, yielding a topological superradiant state. We map out the steady-state phase diagram of the system in the presence of an effective Zeeman field, and identify a critical tetracritical point beyond which the topological and the conventional superraidiant phase boundaries separate. We propose to detect the topological phase transition based on its signatures in either the momentum distribution of the atoms or in the cavity photon occupation.

  9. Retinas in a Dish Peek into Inherited Retinal Degeneration.

    PubMed

    Duong, Thu T; Vasireddy, Vidyullatha; Mills, Jason A; Bennett, Jean

    2016-06-01

    Human retinal degeneration can cause blindness, and the lack of relevant model systems has made identifying underlying mechanisms challenging. Parfitt et al. (2016) generate three-dimensional retinal tissue from patient-derived induced pluripotent stem cells to identify how CEP290 mutations cause retinal degeneration, and show an antisense approach can correct disease-associated phenotypes. PMID:27257755

  10. 9 CFR 311.35 - Muscular inflammation, degeneration, or infiltration.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Muscular inflammation, degeneration, or infiltration. 311.35 Section 311.35 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE... PARTS § 311.35 Muscular inflammation, degeneration, or infiltration. (a) If muscular lesions are...

  11. 9 CFR 311.35 - Muscular inflammation, degeneration, or infiltration.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 9 Animals and Animal Products 2 2011-01-01 2011-01-01 false Muscular inflammation, degeneration, or infiltration. 311.35 Section 311.35 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE... PARTS § 311.35 Muscular inflammation, degeneration, or infiltration. (a) If muscular lesions are...

  12. [Depression in Patients with Age-Related Macular Degeneration].

    PubMed

    Narváez, Yamile Reveiz; Gómez-Restrepo, Carlos

    2012-09-01

    Age-related macular degeneration is a cause for disability in the elderly since it greatly affects their quality of life and increases depression likelihood. This article discusses the negative effect depression has on patients with age-related macular degeneration and summarizes the interventions available for decreasing their depression index. PMID:26572116

  13. 9 CFR 311.35 - Muscular inflammation, degeneration, or infiltration.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 9 Animals and Animal Products 2 2014-01-01 2014-01-01 false Muscular inflammation, degeneration, or infiltration. 311.35 Section 311.35 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE... PARTS § 311.35 Muscular inflammation, degeneration, or infiltration. (a) If muscular lesions are...

  14. 9 CFR 311.35 - Muscular inflammation, degeneration, or infiltration.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 9 Animals and Animal Products 2 2013-01-01 2013-01-01 false Muscular inflammation, degeneration, or infiltration. 311.35 Section 311.35 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE... PARTS § 311.35 Muscular inflammation, degeneration, or infiltration. (a) If muscular lesions are...

  15. 9 CFR 311.35 - Muscular inflammation, degeneration, or infiltration.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 9 Animals and Animal Products 2 2012-01-01 2012-01-01 false Muscular inflammation, degeneration, or infiltration. 311.35 Section 311.35 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE... PARTS § 311.35 Muscular inflammation, degeneration, or infiltration. (a) If muscular lesions are...

  16. Does lumbar facet arthrosis precede disc degeneration? A postmortem study.

    PubMed

    Eubanks, Jason David; Lee, Michael J; Cassinelli, Ezequiel; Ahn, Nicholas U

    2007-11-01

    It is believed lumbar degeneration begins in the disc, where desiccation and collapse lead to instability and compensatory facet arthrosis. We explored the contrary contention that facet degeneration precedes disc degeneration by examining 647 skeletal lumbar spines. Using facet osteophytosis as a measure of facet degeneration and vertebral rim osteophytosis as a measure of disc degeneration, we assumed bone degeneration in both locations equally reflected the progression of those in the soft tissues. We graded arthrosis Grade 0 to 4 on a continuum from no arthritis to ankylosis. The data were analyzed for different age groups to examine patterns of degeneration with age. Specimens younger than 30 years of age had a higher prevalence of facet osteophytosis compared with vertebral rim osteophotosis at L1-L2 and L2-L3. Specimens aged 30 to 39 years showed more facet osteophytosis than vertebral rim osteophytosis at L4-L5. Specimens older than 40 years, however, showed more vertebral rim osteophytosis compared with facet osteophytosis at all levels except L4-L5 and L5-S1. This skeletal study suggests facet osteophytosis appears early in the degenerative process, preceding vertebral rim osteophytosis of degenerating intervertebral discs. However, once facets begin deteriorating with age, vertebral rim osteophytosis overtakes continued facet osteophytosis. These data challenge the belief that facet osteophytosis follows vertebral rim osteophytosis; rather, it appears vertebral rim osteophytosis progresses more rapidly in later years, but facet osteophotosis occurs early, predominating in younger individuals. PMID:17767079

  17. Crystallization and collapse in relativistically degenerate matter

    SciTech Connect

    Akbari-Moghanjoughi, M.

    2013-04-15

    In this paper, it is shown that a mass density limit exists beyond which the relativistically degenerate matter would crystallize. The mass density limit, found here, is quite analogous to the mass limit predicted by Chandrasekhar for a type of compact stars called white dwarfs (M{sub Ch} Asymptotically-Equal-To 1.43 Solar Mass). In this study, the old problem of white dwarf core collapse, which has been previously investigated by Chandrasekhar using hydrostatic stability criteria, is revisited in the framework of the quantum hydrodynamics model by inspection of the charge screening at atomic scales in the relativistic degeneracy plasma regime taking into account the relativistic Fermi-Dirac statistics and electron interaction features such as the quantum statistical pressure, Coulomb attraction, electron exchange-correlation, and quantum recoil effects. It is revealed that the existence of ion correlation and crystallization of matter in the relativistically degenerate plasma puts a critical mass density limit on white dwarf core region. It is shown that a white dwarf star with a core mass density beyond this critical limit can undergo the spontaneous core collapse (SCC). The SCC phenomenon, which is dominantly caused by the electron quantum recoil effect (interference and localization of the electron wave function), leads to a new exotic state of matter. In such exotic state, the relativistic electron degeneracy can lead the white dwarf crystallized core to undergo the nuclear fusion and an ultimate supernova by means of the volume reduction (due to the enhanced compressibility) and huge energy release (due to the increase in cohesive energy), under the stars huge inward gravitational pressure. Moreover, it is found that the SCC phenomenon is significantly affected by the core composition (it is more probable for heavier plasmas). The critical mass density found here is consistent with the values calculated for core density of typical white dwarf stars.

  18. Retrograde Axonal Degeneration in Parkinson Disease

    PubMed Central

    Tagliaferro, Patricia; Burke, Robert E.

    2016-01-01

    In spite of tremendous research efforts we have not yet achieved two of our principal therapeutic goals in the treatment of Parkinson’s disease (PD), to prevent its onward progression and to provide restoration of systems that have already been damaged by the time of diagnosis. There are many possible reasons for our inability to make progress. One possibility is that our efforts thus far may not have been directed towards the appropriate cellular compartments. Up until now research has been largely focused on the loss of neurons in the disease. Thus, neuroprotection approaches have been largely aimed at blocking mechanisms that lead to destruction of the neuronal cell body. Attempts to provide neurorestoration have been almost entirely focused on replacement of neurons. We herein review the evidence that the axonal component of diseased neuronal systems merit more of our attention. Evidence from imaging studies, from postmortem neurochemical studies, and from genetic animal models suggests that the axons of the dopaminergic system are involved predominantly and early in PD. Since the mechanisms of axonal destruction are distinct from those of neuron cell body degeneration, a focus on axonal neurobiology will offer new opportunities for preventing their degeneration. At present these mechanisms remain largely obscure. However, defining them is likely to offer new opportunities for neuroprotection. In relation to neurorestoration, while it has been classically believed that neurons of the adult central nervous system are incapable of new axon growth, recent evidence shows that this is not true for the dopaminergic projection. In conclusion, the neurobiology of axons is likely to offer many new approaches to protective and restorative therapeutics. PMID:27003783

  19. Preservation of retinotopic map in retinal degeneration.

    PubMed

    Xie, John; Wang, Gene-Jack; Yow, Lindy; Humayun, Mark S; Weiland, James D; Cela, Carlos J; Jadvar, Hossein; Lazzi, Gianluca; Dhrami-Gavazi, Elona; Tsang, Stephen H

    2012-05-01

    Retinal degenerations trigger the loss of photoreceptors and cause the remaining de-afferented neural retina to undergo remodeling. Concerns over this potential retinal synaptic reorganization following visual loss have raised questions regarding the usefulness of visual restoration via retinal electrical stimulation. We have used quantitative positron emission tomography (PET) and 2-deoxy-2-[18F]fluoro-d-glucose (FDG) to objectively evaluate the connection between the retina and the primary visual cortex under both light and transcorneal electrical stimulation (TcES) in five subjects with retinal degeneration (RD) who have had more than ten years of light-perception-only best visual acuity and five age-matched normal-sighted controls. All subjects underwent quantitative PET with FDG as the metabolic tracer during stimulation of the right eye under both light stimulation condition and transcorneal electrical stimulation (TcES) using ERG-Jet contact lens electrode. Cortical activation maps from each stimulation condition were obtained using statistical parametric mapping. TcES phosphene threshold current and qualitative visual cortex activation from both stimulation conditions were compared between the two subject groups. Average phosphene threshold current was 0.72 ± 0.18 mA for the five normal-sighted controls and 3.08 ± 2.01 mA for the retinal degenerative subjects. Phosphene threshold current was significantly higher in retinal degenerative subjects compared to normal-sighted controls (p < 0.05). We found both light stimulation and TcES resulted in retinotopically mapped primary visual cortex activation in both groups. In addition, the patterns of early visual area activation between the two subject groups are more similar during TcES than light stimulation. Our findings suggest primary visual cortex continues to maintain its retinotopy in RD subjects despite prolonged visual loss. PMID:22685713

  20. Transurethral resection and degeneration of bladder tumour

    PubMed Central

    Li, Aihua; Fang, Wei; Zhang, Feng; Li, Weiwu; Lu, Honghai; Liu, Sikuan; Wang, Hui; Zhang, Binghui

    2013-01-01

    Introduction: We evaluate the efficacy and safety of transurethral resection and degeneration of bladder tumour (TURD-Bt). Methods: In total, 56 patients with bladder tumour were treated by TURD-Bt. The results in these patients were compared with 32 patients treated by current transurethral resection of bladder tumour (TUR-Bt). Patients with or without disease progressive factors were respectively compared between the 2 groups. The factors included recurrent tumour, multiple tumours, tumour ≥3 cm in diameter, clinical stage T2, histological grade 3, adenocarcinoma, and ureteral obstruction or hydronephrosis. Results: Follow-up time was 48.55 ± 23.74 months in TURD-Bt group and 56.28 ± 17.61 months in the TUR-Bt group (p > 0.05). In patients without progressive factors, no tumour recurrence was found and overall survival was 14 (100%) in the TURD-Bt group; 3 (37.50%) patients had recurrence and overall survival was 5 (62.5%) in the TUR-Bt group. In patients with progressive factors, 8 (19.05%) patients had tumour recurrence, overall survival was 32 (76.19%) and cancer death was 3 (7.14%) in TURD-Bt group; 18 (75.00%) patients had tumour recurrence (p < 0.05), overall survival was 12 (50.00%) (p < 0.01) and cancer death was 8 (33.33%) (p < 0.05) in TUR-Bt group. No significant complication was found in TURD-Bt group. Conclusion: This study suggests that complete resection and degeneration of bladder tumour can be expected by TURD-Bt. The surgical procedure is safe and efficacious, and could be predictable and controllable before and during surgery. We would conclude that for bladder cancers without lymph node metastasis and distal metastasis, TURD-Bt could be performed to replace radical TUR-Bt and preserve the bladder. PMID:24475002

  1. Displaced retinal ganglion cells in albino and pigmented rats

    PubMed Central

    Nadal-Nicolás, Francisco M.; Salinas-Navarro, Manuel; Jiménez-López, Manuel; Sobrado-Calvo, Paloma; Villegas-Pérez, María P.; Vidal-Sanz, Manuel; Agudo-Barriuso, Marta

    2014-01-01

    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 ± 1249 in albino and 90,440 ± 2236 in pigmented, out of which 2383 and 2428 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 ocular hypertension. Although the role of mammalian dRGCs remains to be determined, our data suggest that they are not misplaced by an

  2. Calcium preconditioning triggers neuroprotection in retinal ganglion cells.

    PubMed

    Brandt, S K; Weatherly, M E; Ware, L; Linn, D M; Linn, C L

    2011-01-13

    In the mammalian retina, excitotoxicity has been shown to be involved in apoptotic retinal ganglion cell (RGC) death and is associated with certain retinal disease states including glaucoma, diabetic retinopathy and retinal ischemia. Previous studies from this lab [Wehrwein E, Thompson SA, Coulibaly SF, Linn DM, Linn CL (2004) Invest Ophthalmol Vis Sci 45:1531-1543] have demonstrated that acetylcholine (ACh) and nicotine protects against glutamate-induced excitotoxicity in isolated adult pig RGCs through nicotinic acetylcholine receptors (nAChRs). Activation of nAChRs in these RGCs triggers cell survival signaling pathways and inhibits apoptotic enzymes [Asomugha CO, Linn DM, Linn CL (2010) J Neurochem 112:214-226]. However, the link between binding of nAChRs and activation of neuroprotective pathways is unknown. In this study, we examine the hypothesis that calcium permeation through nAChR channels is required for ACh-induced neuroprotection against glutamate-induced excitotoxicity in isolated pig RGCs. RGCs were isolated from other retinal tissue using a two step panning technique and cultured for 3 days under different conditions. In some studies, calcium imaging experiments were performed using the fluorescent calcium indicator, fluo-4, and demonstrated that calcium permeates the nAChR channels located on pig RGCs. In other studies, the extracellular calcium concentration was altered to determine the effect on nicotine-induced neuroprotection. Results support the hypothesis that calcium is required for nicotine-induced neuroprotection in isolated pig RGCs. Lastly, studies were performed to analyze the effects of preconditioning on glutamate-induced excitotoxicity and neuroprotection. In these studies, a preconditioning dose of calcium was introduced to cells using a variety of mechanisms before a large glutamate insult was applied to cells. Results from these studies support the hypothesis that preconditioning cells with a relatively low level of calcium before

  3. Accelerated cellular senescence in degenerate intervertebral discs: a possible role in the pathogenesis of intervertebral disc degeneration

    PubMed Central

    Le Maitre, Christine Lyn; Freemont, Anthony John; Hoyland, Judith Alison

    2007-01-01

    Current evidence implicates intervertebral disc degeneration as a major cause of low back pain, although its pathogenesis is poorly understood. Numerous characteristic features of disc degeneration mimic those seen during ageing but appear to occur at an accelerated rate. We hypothesised that this is due to accelerated cellular senescence, which causes fundamental changes in the ability of disc cells to maintain the intervertebral disc (IVD) matrix, thus leading to IVD degeneration. Cells isolated from non-degenerate and degenerate human tissue were assessed for mean telomere length, senescence-associated β-galactosidase (SA-β-gal), and replicative potential. Expression of P16INK4A (increased in cellular senescence) was also investigated in IVD tissue by means of immunohistochemistry. RNA from tissue and cultured cells was used for real-time polymerase chain reaction analysis for matrix metalloproteinase-13, ADAMTS 5 (a disintegrin and metalloprotease with thrombospondin motifs 5), and P16INK4A. Mean telomere length decreased with age in cells from non-degenerate tissue and also decreased with progressive stages of degeneration. In non-degenerate discs, there was an age-related increase in cellular expression of P16INK4A. Cells from degenerate discs (even from young patients) exhibited increased expression of P16INK4A, increased SA-β-gal staining, and a decrease in replicative potential. Importantly, there was a positive correlation between P16INK4A and matrix-degrading enzyme gene expression. Our findings indicate that disc cell senescence occurs in vivo and is accelerated in IVD degeneration. Furthermore, the senescent phenotype is associated with increased catabolism, implicating cellular senescence in the pathogenesis of IVD degeneration. PMID:17498290

  4. Accelerated cellular senescence in degenerate intervertebral discs: a possible role in the pathogenesis of intervertebral disc degeneration.

    PubMed

    Le Maitre, Christine Lyn; Freemont, Anthony John; Hoyland, Judith Alison

    2007-01-01

    Current evidence implicates intervertebral disc degeneration as a major cause of low back pain, although its pathogenesis is poorly understood. Numerous characteristic features of disc degeneration mimic those seen during ageing but appear to occur at an accelerated rate. We hypothesised that this is due to accelerated cellular senescence, which causes fundamental changes in the ability of disc cells to maintain the intervertebral disc (IVD) matrix, thus leading to IVD degeneration. Cells isolated from non-degenerate and degenerate human tissue were assessed for mean telomere length, senescence-associated beta-galactosidase (SA-beta-gal), and replicative potential. Expression of P16INK4A (increased in cellular senescence) was also investigated in IVD tissue by means of immunohistochemistry. RNA from tissue and cultured cells was used for real-time polymerase chain reaction analysis for matrix metalloproteinase-13, ADAMTS 5 (a disintegrin and metalloprotease with thrombospondin motifs 5), and P16INK4A. Mean telomere length decreased with age in cells from non-degenerate tissue and also decreased with progressive stages of degeneration. In non-degenerate discs, there was an age-related increase in cellular expression of P16INK4A. Cells from degenerate discs (even from young patients) exhibited increased expression of P16INK4A, increased SA-beta-gal staining, and a decrease in replicative potential. Importantly, there was a positive correlation between P16INK4A and matrix-degrading enzyme gene expression. Our findings indicate that disc cell senescence occurs in vivo and is accelerated in IVD degeneration. Furthermore, the senescent phenotype is associated with increased catabolism, implicating cellular senescence in the pathogenesis of IVD degeneration. PMID:17498290

  5. SARM1 activation triggers axon degeneration locally via NAD+ destruction

    PubMed Central

    Gerdts, Josiah; Brace, E.J.; Sasaki, Yo; DiAntonio, Aaron

    2015-01-01

    Axon degeneration is an intrinsic self-destruction program that underlies axon loss during injury and disease. Sterile alpha and TIR motif containing 1 (SARM1) protein is an essential mediator of axon degeneration. We report that SARM1 initiates a local destruction program involving rapid breakdown of NAD+ after injury. We used an engineered protease-sensitized SARM1 to demonstrate that SARM1 activity is required after axon injury to induce axon degeneration. Dimerization of the Toll-Interleukin Receptor (TIR) domain of SARM1 alone was sufficient to induce locally-mediated axon degeneration. Formation of the SARM1 TIR dimer triggered rapid breakdown of NAD+, whereas SARM1-induced axon destruction could be counteracted by increased NAD+ synthesis. SARM1-induced depletion of NAD+ may explain the potent axon protection in Wallerian Degeneration slow (Wlds) mutant mice. PMID:25908823

  6. Anomalous skin effects in a weakly magnetized degenerate electron plasma

    NASA Astrophysics Data System (ADS)

    Abbas, G.; Sarfraz, M.; Shah, H. A.

    2014-09-01

    Fully relativistic analysis of anomalous skin effects for parallel propagating waves in a weakly magnetized degenerate electron plasma is presented and a graphical comparison is made with the results obtained using relativistic Maxwellian distribution function [G. Abbas, M. F. Bashir, and G. Murtaza, Phys. Plasmas 18, 102115 (2011)]. It is found that the penetration depth for R- and L-waves for degenerate case is qualitatively small in comparison with the Maxwellian plasma case. The quantitative reduction due to weak magnetic field in the skin depth in R-wave for degenerate plasma is large as compared to the non-degenerate one. By ignoring the ambient magnetic field, previous results for degenerate field free case are salvaged [A. F. Alexandrov, A. S. Bogdankevich, and A. A. Rukhadze, Principles of Plasma Electrodynamics (Springer-Verlag, Berlin/Heidelberg, 1984), p. 90].

  7. Progranulin Knockout Accelerates Intervertebral Disc Degeneration in Aging Mice

    PubMed Central

    Zhao, Yun-peng; Tian, Qing-yun; Liu, Ben; Cuellar, Jason; Richbourgh, Brendon; Jia, Tang-hong; Liu, Chuan-ju

    2015-01-01

    Intervertebral disc (IVD) degeneration is a common degenerative disease, yet much is unknown about the mechanisms during its pathogenesis. Herein we investigated whether progranulin (PGRN), a chondroprotective growth factor, is associated with IVD degeneration. PGRN was detectable in both human and murine IVD. The levels of PGRN were upregulated in murine IVD tissue during aging process. Loss of PGRN resulted in an early onset of degenerative changes in the IVD tissue and altered expressions of the degeneration-associated molecules in the mouse IVD tissue. Moreover, PGRN knockout mice exhibited accelerated IVD matrix degeneration, abnormal bone formation and exaggerated bone resorption in vertebra with aging. The acceleration of IVD degeneration observed in PGRN null mice was probably due to the enhanced activation of NF-κB signaling and β-catenin signaling. Taken together, PGRN may play a critical role in homeostasis of IVD, and may serve as a potential molecular target for prevention and treatment of disc degenerative diseases. PMID:25777988

  8. Versal unfolding of planar Hamiltonian systems at fully degenerate equilibrium

    NASA Astrophysics Data System (ADS)

    Tang, Yilei; Zhang, Weinian

    2016-07-01

    In this paper we study bifurcations of a planar Hamiltonian system at a fully degenerate equilibrium, which has a zero linearization. Since the Poincaré normal form theory is not applicable to such a degenerate system, we investigate its restrictive normal forms in the class of Hamiltonian fields and prove that such a degenerate system is of codimension 3 degeneracy in the class, so that we introduce three parameters to versally unfold the degenerate system in the class. In order to discuss further the qualitative properties of the versal unfolding, we use the Poincaré index to determine the number and distribution of hyperbolic sectors near the degenerate equilibrium. We display its all bifurcations such as pitchfork bifurcation, saddle-center bifurcation and the Bogdanov-Takens bifurcation within Hamiltonian systems.

  9. Anomalous skin effects in a weakly magnetized degenerate electron plasma

    SciTech Connect

    Abbas, G. Sarfraz, M.; Shah, H. A.

    2014-09-15

    Fully relativistic analysis of anomalous skin effects for parallel propagating waves in a weakly magnetized degenerate electron plasma is presented and a graphical comparison is made with the results obtained using relativistic Maxwellian distribution function [G. Abbas, M. F. Bashir, and G. Murtaza, Phys. Plasmas 18, 102115 (2011)]. It is found that the penetration depth for R- and L-waves for degenerate case is qualitatively small in comparison with the Maxwellian plasma case. The quantitative reduction due to weak magnetic field in the skin depth in R-wave for degenerate plasma is large as compared to the non-degenerate one. By ignoring the ambient magnetic field, previous results for degenerate field free case are salvaged [A. F. Alexandrov, A. S. Bogdankevich, and A. A. Rukhadze, Principles of Plasma Electrodynamics (Springer-Verlag, Berlin/Heidelberg, 1984), p. 90].

  10. Caspase-3 dependent nitrergic neuronal apoptosis following cavernous nerve injury is mediated via RhoA and ROCK activation in major pelvic ganglion.

    PubMed

    Hannan, Johanna L; Matsui, Hotaka; Sopko, Nikolai A; Liu, Xiaopu; Weyne, Emmanuel; Albersen, Maarten; Watson, Joseph W; Hoke, Ahmet; Burnett, Arthur L; Bivalacqua, Trinity J

    2016-01-01

    Axonal injury due to prostatectomy leads to Wallerian degeneration of the cavernous nerve (CN) and erectile dysfunction (ED). Return of potency is dependent on axonal regeneration and reinnervation of the penis. Following CN injury (CNI), RhoA and Rho-associated protein kinase (ROCK) increase in penile endothelial and smooth muscle cells. Previous studies indicate that nerve regeneration is hampered by activation of RhoA/ROCK pathway. We evaluated the role of RhoA/ROCK pathway in CN regulation following CNI using a validated rat model. CNI upregulated gene and protein expression of RhoA/ROCK and caspase-3 mediated apoptosis in the major pelvic ganglion (MPG). ROCK inhibitor (ROCK-I) prevented upregulation of RhoA/ROCK pathway as well as activation of caspase-3 in the MPG. Following CNI, there was decrease in the dimer to monomer ratio of neuronal nitric oxide synthase (nNOS) protein and lowered NOS activity in the MPG, which were prevented by ROCK-I. CNI lowered intracavernous pressure and impaired non-adrenergic non-cholinergic-mediated relaxation in the penis, consistent with ED. ROCK-I maintained the intracavernous pressure and non-adrenergic non-cholinergic-mediated relaxation in the penis following CNI. These results suggest that activation of RhoA/ROCK pathway mediates caspase-3 dependent apoptosis of nitrergic neurons in the MPG following CNI and that ROCK-I can prevent post-prostatectomy ED. PMID:27388816

  11. Activation of transient receptor potential vanilloid-1 (TRPV1) influences how retinal ganglion cell neurons respond to pressure-related stress

    PubMed Central

    Sappington, Rebecca M; Sidorova, Tatiana; Ward, Nicholas J; Chakravarthy, Rohini; Ho, Karen W; Calkins, David J

    2015-01-01

    Our recent studies implicate the transient receptor potential vanilloid-1 (TRPV1) channel as a mediator of retinal ganglion cell (RGC) function and survival. With elevated pressure in the eye, TRPV1 increases in RGCs, supporting enhanced excitability, while Trpv1 -/- accelerates RGC degeneration in mice. Here we find TRPV1 localized in monkey and human RGCs, similar to rodents. Expression increases in RGCs exposed to acute changes in pressure. In retinal explants, contrary to our animal studies, both Trpv1 -/- and pharmacological antagonism of the channel prevented pressure-induced RGC apoptosis, as did chelation of extracellular Ca2+. Finally, while TRPV1 and TRPV4 co-localize in some RGC bodies and form a protein complex in the retina, expression of their mRNA is inversely related with increasing ocular pressure. We propose that TRPV1 activation by pressure-related insult in the eye initiates changes in expression that contribute to a Ca2+-dependent adaptive response to maintain excitatory signaling in RGCs. PMID:25713995

  12. Caspase-3 dependent nitrergic neuronal apoptosis following cavernous nerve injury is mediated via RhoA and ROCK activation in major pelvic ganglion

    PubMed Central

    Hannan, Johanna L.; Matsui, Hotaka; Sopko, Nikolai A.; Liu, Xiaopu; Weyne, Emmanuel; Albersen, Maarten; Watson, Joseph W.; Hoke, Ahmet; Burnett, Arthur L.; Bivalacqua, Trinity J.

    2016-01-01

    Axonal injury due to prostatectomy leads to Wallerian degeneration of the cavernous nerve (CN) and erectile dysfunction (ED). Return of potency is dependent on axonal regeneration and reinnervation of the penis. Following CN injury (CNI), RhoA and Rho-associated protein kinase (ROCK) increase in penile endothelial and smooth muscle cells. Previous studies indicate that nerve regeneration is hampered by activation of RhoA/ROCK pathway. We evaluated the role of RhoA/ROCK pathway in CN regulation following CNI using a validated rat model. CNI upregulated gene and protein expression of RhoA/ROCK and caspase-3 mediated apoptosis in the major pelvic ganglion (MPG). ROCK inhibitor (ROCK-I) prevented upregulation of RhoA/ROCK pathway as well as activation of caspase-3 in the MPG. Following CNI, there was decrease in the dimer to monomer ratio of neuronal nitric oxide synthase (nNOS) protein and lowered NOS activity in the MPG, which were prevented by ROCK-I. CNI lowered intracavernous pressure and impaired non-adrenergic non-cholinergic-mediated relaxation in the penis, consistent with ED. ROCK-I maintained the intracavernous pressure and non-adrenergic non-cholinergic-mediated relaxation in the penis following CNI. These results suggest that activation of RhoA/ROCK pathway mediates caspase-3 dependent apoptosis of nitrergic neurons in the MPG following CNI and that ROCK-I can prevent post-prostatectomy ED. PMID:27388816

  13. Effects of GABA receptor antagonists on thresholds of P23H rat retinal ganglion cells to electrical stimulation of the retina

    NASA Astrophysics Data System (ADS)

    Jensen, Ralph J.; Rizzo, Joseph F., III

    2011-06-01

    An electronic retinal prosthesis may provide useful vision for patients suffering from retinitis pigmentosa (RP). In animal models of RP, the amount of current needed to activate retinal ganglion cells (RGCs) is higher than in normal, healthy retinas. In this study, we sought to reduce the stimulation thresholds of RGCs in a degenerate rat model (P23H-line 1) by blocking GABA receptor mediated inhibition in the retina. We examined the effects of TPMPA, a GABAC receptor antagonist, and SR95531, a GABAA receptor antagonist, on the electrically evoked responses of RGCs to biphasic current pulses delivered to the subretinal surface through a 400 µm diameter electrode. Both TPMPA and SR95531 reduced the stimulation thresholds of ON-center RGCs on average by 15% and 20% respectively. Co-application of the two GABA receptor antagonists had the greatest effect, on average reducing stimulation thresholds by 32%. In addition, co-application of the two GABA receptor antagonists increased the magnitude of the electrically evoked responses on average three-fold. Neither TPMPA nor SR95531, applied alone or in combination, had consistent effects on the stimulation thresholds of OFF-center RGCs. We suggest that the effects of the GABA receptor antagonists on ON-center RGCs may be attributable to blockage of GABA receptors on the axon terminals of ON bipolar cells.

  14. Contribution of the GABAergic pathway(s) to the correlated activities of chicken retinal ganglion cells.

    PubMed

    Liu, Xue; Zhou, Yi; Gong, Hai-Qing; Liang, Pei-Ji

    2007-10-26

    In the present study, the spatiotemporal pattern of chicken retinal ganglion cells' firing activity in response to full-field white light stimulation was investigated. Cross-correlation analysis showed that ganglion cells of sustained subtype fired in precise synchrony with their adjacent neurons of the same subtype (delay lag within 2 ms, narrow correlation). On the other hand, the activities of neighboring ganglion cells of transient subtype were correlated with distributed time lags (10-30 ms, medium correlation). Pharmacological studies demonstrated that the intensity of the medium correlations could be strengthened when exogenous GABA was applied and attenuated when GABA receptors were blocked by picrotoxin. Meanwhile, the GABAergic modulation on the narrow correlations was not consistent. These results suggest that, in the chicken retina, GABAergic pathway(s) are likely involved in the formation of medium correlations between ganglion cells. Neurons might fire at a lower rate but with higher level of synchronization to improve the efficiency of information transmission, with the mechanism involving the GABAergic inhibitory input. PMID:17919471

  15. A minute fraction of Syrian golden hamster retinal ganglion cells project bilaterally.

    PubMed

    Hsiao, K; Sachs, G M; Schneider, G E

    1984-02-01

    Bilaterally projecting retinal ganglion cells (BPRGCs) in the adult Syrian golden hamster were identified through the use of two retrogradely transported neuronal labels, horseradish peroxidase and Nuclear Yellow, placed separately in each optic tract. The distribution and size of doubly labeled retinal ganglion cells were characterized and their numbers were determined. Strict criteria were used to exclude artifactual doubly labeled cells. This work revealed that: (a) BPRGCs comprise less than 0.01% of the entire retinal ganglion cell population, averaging 7.4 (SD = 3) cells per retina; (b) BPRGCs are found primarily in the upper, peripheral retina and not along the vertical meridian or in the temporal crescent; and (c) BPRGCs correspond in size to ordinary retinal ganglion cells in their immediate vicinity, thus providing no evidence that they comprise a separate population of cells. Electrophysiological collision experiments were also performed, with stimulating electrodes in the two brachia of the superior colliculi and a recording electrode in one optic nerve. A collision effect was not detected, thus supporting the anatomical findings of rare bilateral branching of optic nerve axons. The occurrence of BPRGCs may reflect occasional ambiguities in the cues that guide axons through the chiasm. PMID:6199482

  16. Subtype Identification in Acutely Dissociated Rat Nodose Ganglion Neurons Based on Morphologic Parameters

    PubMed Central

    Lu, Xiao-Long; Xu, Wen-Xiao; Yan, Zhen-Yu; Qian, Zhao; Xu, Bing; Liu, Yang; Han, Li-Min; Gao, Rui-Chen; Li, Jun-Nan; Yuan, Mei; Zhao, Chong-Bao; Qiao, Guo-fen; Li, Bai-Yan

    2013-01-01

    Nodose ganglia are composed of A-, Ah- and C-type neurons. Despite their important roles in regulating visceral afferent function, including cardiovascular, pulmonary, and gastrointestinal homeostasis, information about subtype-specific expression, molecular identity, and function of individual ion transporting proteins is scarce. Although experiments utilizing the sliced ganglion preparation have provided valuable insights into the electrophysiological properties of nodose ganglion neuron subtypes, detailed characterization of their electrical phenotypes will require measurements in isolated cells. One major unresolved problem, however, is the difficulty to unambiguously identify the subtype of isolated nodose ganglion neurons without current-clamp recording, because the magnitude of conduction velocity in the corresponding afferent fiber, a reliable marker to discriminate subtypes in situ, can no longer be determined. Here, we present data supporting the notion that application of an algorithm regarding to microscopic structural characteristics, such as neuron shape evaluated by the ratio between shortest and longest axis, neuron surface characteristics, like membrane roughness, and axon attachment, enables specific and sensitive subtype identification of acutely dissociated rat nodose ganglion neurons, by which the accuracy of identification is further validated by electrophysiological markers and overall positive predictive rates is 89.26% (90.04%, 76.47%, and 98.21% for A-, Ah, and C-type, respectively). This approach should aid in gaining insight into the molecular correlates underlying phenotypic heterogeneity of nodose ganglia. Additionally, several critical points that help for neuron identification and afferent conduction calibration are also discussed. PMID:23904796

  17. Expression of pro-opiomelanocortin (POMC) in the cerebral ganglion and ovary of a protochordate.

    PubMed

    Masini, M A; Sturla, M; Gallinelli, A; Candiani, S; Facchinetti, F; Pestarino, M

    1998-01-01

    The distribution of neurones expressing POMC mRNA in the cerebral ganglion of the protochordate ascidian, Styela plicata, was investigated using a non-radioactive in situ hybridization technique. Nerve cell bodies of mono and bipolar types expressing POMC mRNA, were observed mainly in the outer layer of the ganglion. Discrete groups of neurones containing POMC mRNA were also localized in the inner portion of the ganglion, and few small monopolar perykaria expressing POMC mRNA were visible at the emergence of the main nerve trunks. POMC mRNA labeling was also found at level of the cytoplasm of previtellogenic and vitellogenic oocytes, and of follicular cells. Our results demonstrate the expression of one or more genes in the cerebral ganglion and ovary, that may be similar to one or more regions of the mammalian POMC gene. Therefore POMC-related molecules seem to be involved in neuromodulatory pathways and regulatory mechanisms of the oogenesis of ascidians. PMID:9786167

  18. Meningitis and Bacteremia Due to Neisseria cinerea following a Percutaneous Rhizotomy of the Trigeminal Ganglion

    PubMed Central

    Richter, H.; Bruderer, T.; Goldenberger, D.; Emonet, S.; Strahm, C.

    2015-01-01

    Neisseria cinerea is a human commensal. The first known case of meningitis and bacteremia due to Neisseria cinerea following percutaneous glycerol instillation of the trigeminal ganglion is reported. Conventional phenotypic methods and complete 16S RNA gene sequencing accurately identified the pathogen. Difficulties in differentiation from pathogenic neisseriae are discussed. PMID:26511743

  19. Expression of zinc transporter ZnT7 in mouse superior cervical ganglion

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The superior cervical ganglion (SCG) neurons contain a considerable amount of zinc ions, but little is known about zinc homeostasis in the SCG. It is known that zinc transporter 7 (ZnT7, Slc30a7), a member of the Slc30 ZnT family, is involved in mobilizing zinc ions from the cytoplasm into the Golgi...

  20. Quantifying Spiral Ganglion Neurite and Schwann Behavior on Micropatterned Polymer Substrates.

    PubMed

    Cheng, Elise L; Leigh, Braden; Guymon, C Allan; Hansen, Marlan R

    2016-01-01

    The first successful in vitro experiments on the cochlea were conducted in 1928 by Honor Fell (Fell, Arch Exp Zellforsch 7(1):69-81, 1928). Since then, techniques for culture of this tissue have been refined, and dissociated primary culture of the spiral ganglion has become a widely accepted in vitro model for studying nerve damage and regeneration in the cochlea. Additionally, patterned substrates have been developed that facilitate and direct neural outgrowth. A number of automated and semi-automated methods for quantifying this neurite outgrowth have been utilized in recent years (Zhang et al., J Neurosci Methods 160(1):149-162, 2007; Tapias et al., Neurobiol Dis 54:158-168, 2013). Here, we describe a method to study the effect of topographical cues on spiral ganglion neurite and Schwann cell alignment. We discuss our microfabrication process, characterization of pattern features, cell culture techniques for both spiral ganglion neurons and spiral ganglion Schwann cells. In addition, we describe protocols for reducing fibroblast count, immunocytochemistry, and methods for quantifying neurite and Schwann cell alignment. PMID:27259935

  1. Immunocytochemistry of GABA in the brain and suboesophageal ganglion of Manduca sexta.

    PubMed

    Homberg, U; Kingan, T G; Hildebrand, J G

    1987-04-01

    We have used specific antisera against protein-conjugated gamma-aminobutyric acid (GABA) in immunocytochemical preparations to investigate the distribution of putatively GABAergic neurons in the brain and suboesophageal ganglion of the sphinx moth Manduca sexta. About 20,000 neurons per brain hemisphere exhibit GABA-immunoreactivity. Most of these are optic-lobe interneurons, especially morphologically centrifugal neurons of the lamina and tangential neurons that innervate the medulla or the lobula complex. Many GABA-immunoreactive neurons, among them giant fibers of the lobula plate, project into the median protocerebrum. Among prominent GABA-immunoreactive neurons of the median protocerebrum are about 150 putatively negative-feedback fibers of the mushroom body, innervating both the calyces and lobes, and a group of large, fan-shaped neurons of the lower division of the central body. Several commissures in the supra- and suboesophageal ganglion exhibit GABA-like immunoreactivity. In the suboesophageal ganglion, a group of contralaterally descending neurons shows GABA-like immunoreactivity. The frontal ganglion is innervated by immunoreactive processes from the tritocerebrum but does not contain GABA-immunoreactive somata. With few exceptions the brain nerves do not contain GABA-immunoreactive fibers. PMID:3552234

  2. Regional intravenous guanethidine vs. stellate ganglion block in reflex sympathetic dystrophies: a randomized trial.

    PubMed

    Bonelli, S; Conoscente, F; Movilia, P G; Restelli, L; Francucci, B; Grossi, E

    1983-07-01

    Regional intravenous guanethidine blocks and stellate ganglion blocks have been compared in a randomized trial. Nineteen patients, randomly allocated to two groups of therapy and exhibiting severe reflex sympathetic dystrophy following peripheral nerve lesions, have been treated. The performance of the intravenous guanethidine block is of longer duration and superior to stellate ganglion block, as regards some early pharmacological effects (skin temperatures and amplitude of plethysmographic waves recorded before blockade and 15 min, 60 min, 24 h, 48 h after institution of the block). In fact the intravenous guanethidine group shows a persistent and significant increase of the skin temperature and of the plethysmographic traces in the blocked side 24 h and 48 h after blockade in comparison with the patients treated with stellate ganglion block. Concerning the therapeutic effects (changes in pain scores and clinical signs--hyperpathia, allodynia, vasomotor disturbances, trophic changes, oedema and limited motion), recorded at the end of treatment and 1 month and 3 months follow-up, an intravenous guanethidine block carried out every 4 days up to a total of 4 blocks is comparable with a stellate ganglion block every day up to a total of 8 blocks. The results of this study show that regional sympathetic block with guanethidine is a good therapeutic tool in the treatment of reflex dystrophies, especially on account of its negligible risks and contraindications. PMID:6350994

  3. Transient structures of the human fetal brain: subplate, thalamic reticular complex, ganglionic eminence.

    PubMed

    Ulfig, N; Neudörfer, F; Bohl, J

    2000-07-01

    Morphological features of the subplate, the thalamic reticular complex and the ganglionic eminence, which represent three major transient structures of the human fetal forebrain, are summarized with special reference to their functional roles. The subplate harboring various neuronal types is an outstandingly wide zone subjacent to the cortical plate in the human fetal brain. Within the subplate various cortical afferents establish synaptic contacts for a prolonged period before entering the cortical plate. Therefore, the subplate is regarded as a "waiting compartment" which is required for the formation of mature cortical connections. Next to the thalamic reticular nucleus, within the fibers of internal capsule, the perireticular nucleus is located which has been established as a distinct entity during development. Its various neuronal types express a number of different neuroactive substances. Perinatally, the perireticular nucleus is drastically reduced in size. It is involved in the guidance of corticofugal and thalamocortical fibers. The ganglionic eminence is a conspicuous proliferative area that persists throughout nearly the entire fetal period. In the human fetal brain it extends medially upon the dorsal thalamic nuclei which receive precursor cells from the ganglionic eminence. Postmitotic cells in the marginal zone of the ganglionic eminence serve as an intermediate target for growing axons. On the whole, all three structures establish transient neural circuitries that may be essential for the formation of adult projections. The characteristics of the three transient structures are particularly relevant for developmental neuropathology as these structures may be damaged in disorders that preferentially occur in preterm infants. PMID:10963122

  4. Activity of retinal ganglion cells following intense, nanosecond laser flashes. Final report, 1983-1986

    SciTech Connect

    Glickman, R.D.

    1989-01-01

    The effects of intense, but nonlesion-producing, laser exposures of 20-ns duration were determined on the light responses and spontaneous activity of retinal ganglion cells recorded in situ from the rhesus monkey. (Following a single, 20-ns exposure centered on its receptive field, a ganglion cell produced an 'afterdischarge' of maintained action potentials). The duration of the afterdischarge depended on the diameter of the laser beam on the retina and on the beam's intensity. Laser exposures subtending 0.5 to 2.0 deg, and delivering 45 to 60% of the maximum permissible exposure, elicited afterdischarges that lasted up to 80 s. When the beam diameter was decreased to 0.25 deg, the afterdischarge was reduced to 30 s, and to less than 5 s with the 0.12-deg beam. Light sensitivity after the laser exposure recovered rapidly during the first 10 s and then more slowly, but exponentially, until it reached the preflash level. Color-opponent ganglion cells exhibited a phenomenon called 'response-reversal' after the laser exposure, presumably due to selective adaptation of a mid-wavelength cone-input. Because a 20-ns exposure, regardless of intensity, is likely to photoregenerate more than half of the available visual pigment, the effects of ganglion cell response described here are not likely to be due solely to pigment bleaching.

  5. Ocular anatomy, ganglion cell distribution and retinal resolution of a killer whale (Orcinus orca).

    PubMed

    Mass, Alla M; Supin, Alexander Y; Abramov, Andrey V; Mukhametov, Lev M; Rozanova, Elena I

    2013-01-01

    Retinal topography, cell density and sizes of ganglion cells in the killer whale (Orcinus orca) were analyzed in retinal whole mounts stained with cresyl violet. A distinctive feature of the killer whale's retina is the large size of ganglion cells and low cell density compared to terrestrial mammals. The ganglion cell diameter ranged from 8 to 100 µm, with the majority of cells within a range of 20-40 µm. The topographic distribution of ganglion cells displayed two spots of high cell density located in the temporal and nasal quadrants, 20 mm from the optic disk. The high-density areas were connected by a horizontal belt-like area passing below the optic disk of the retina. Peak cell densities in these areas were evaluated. Mean peak cell densities were 334 and 288 cells/mm(2) in the temporal and nasal high-density areas, respectively. With a posterior nodal distance of 19.5 mm, these high-density data predict a retinal resolution of 9.6' (3.1 cycles/deg.) and 12.6' (2.4 cycles/deg.) in the temporal and nasal areas, respectively, in water. PMID:23018493

  6. Retinal ganglion cell topography in juvenile Pacific bluefin tuna Thunnus orientalis (Temminck and Schlegel).

    PubMed

    Miyazaki, Taeko

    2014-02-01

    The retinal ganglion cell distribution, which is known to reflect fish feeding behavior, was investigated in juvenile Pacific bluefin tuna Thunnus orientalis. During the course of examination, regularly arrayed cells with a distinctive larger soma, which may be regarded as motion-sensitive cells, were found. The topographical distribution of ordinary-sized ganglion cells, which is usually utilized to estimate fish visual axis and/or visual field characteristics, showed that the highest-density area, termed the area centralis, was localized in the ventral-temporal retina. The retinal topography of ordinary-sized ganglion cells seems to reflect the bluefin tuna's foraging behavior; while cruising, cells in the area centralis may signal potential prey, such as small schooling pelagic fishes or squids, that are present in the upward-forward direction. Judging from morphological characteristics, the large ganglion cells localized in the small temporal retinal area seem to be equivalent to physiologically categorized off-center Y-cells of cat, which are stimulated by a transient dark spot in a bright visual field. It was inferred that presumed large off-center cells in the temporal retina detect movements of agile prey animals escaping from bluefin tuna as a silhouette against environmental light. PMID:23775518

  7. Ultrasound diagnosis of a ganglion cyst within an extensor digitorum brevis manus muscle.

    PubMed

    Slavchev, S A; Georgiev, G P

    2015-10-01

    A unique case of a ganglion cyst within the extensor digitorum brevis manus muscle diagnosed by ultrasound in an 18-year-old girl is presented. Different anatomical variations and the clinical importance of this accessory muscle are also discussed. PMID:26404797

  8. Intradural extraneural bilobate ganglion cyst of the atlanto-occipital joint compressing the hypoglossal nerve.

    PubMed

    Giordano, Mario; Gerganov, Venelin M; Samii, Amir; Samii, Madjid

    2012-03-01

    Ganglion cysts (ganglia) are benign lesions of the soft tissue arising in the periarticular space. We present a 54-year-old woman with a 5-month history of headache and weakness of the tongue with deviation to the left side who had a rare extraneural intradural bilobate ganglion cyst of the atlanto-occipital joint compressing the hypoglossal nerve. An MRI showed a bilobate cystic lesion in the premedullary cistern on the left side at the level of the hypoglossal canal. This lesion was removed using a lateral suboccipital approach in the semi-sitting position with removal of the C1 hemiarch. The lesion proved to be a ganglion cyst on histopathology. Intracranial juxtafacet (ganglion and synovial) cysts compressing the hypoglossal nerve should be considered in the differential diagnosis with other lesions of this region. Although there was no recurrence at 30-month follow-up, there was no significant improvement of the tongue weakness. We describe our surgical strategy and discuss the pathogenesis of the cyst. PMID:22277565

  9. Suprascapular nerve entrapment at the spinoglenoid notch caused by a ganglion cyst.

    PubMed

    Rachbauer, F; Sterzinger, W; Frischhut, B

    1996-01-01

    A 34-year-old man had right infraspinatus muscle palsy and posterior aching of the shoulder caused by electromyographically confirmed suprascapular nerve entrapment. Sonography and magnetic resonance imaging revealed a cystic lesion at the spinoglenoid notch; this lesion was diagnosed as a ganglion. Operative removal led to immediate pain relief and incomplete recovery of the compressed branches of the suprascapular nerve. PMID:8742880

  10. Double Dart Technique of Instillation of Triamcinolone in Ganglion Over the Wrist

    PubMed Central

    Paramhans, Dharmdas; Nayak, Dilip; Mathur, Raj K; Kushwah, K

    2010-01-01

    Background: Ganglia are the most common benign cystic swellings found over both the dorsal and volar aspects of the wrist. In spite of technical advancement, both operative and non-operative interventions achieve more or less similar results. Complete evacuation of gelatinous fluid followed with intra cystic instillation of triamcinolone has given encouraging results. Aims: To assess the efficacy and safety of drainage of cyst and instillation of triamcinolone in wrist ganglion. Materials and Methods: A prospective study was conducted on patients with simple ganglion cysts on the wrist. Total of 219 patients underwent this study. Out of this, 105 patients underwent the aspiration of the cyst fluid followed by intracystic instillation of triamcinolone, and 114 patients underwent surgical excision of wrist ganglia. Two years follow up was done for recurrence. Results: Most ganglia of wrist occurred in the extensor aspect. Complications noted among the surgically excised group were post operative pain and restricted mobility of wrist with a recurrence rate of 21.5%. Instillation of Triamcinolone into the ganglion yielded early resolution with a low recurrence of 8.4%. Conclusions: Intracystic instillation of triamcinolone after complete evacuation of cyst fluid is a simple and effective technique for treatment of ganglion. PMID:20606991

  11. The place of ganglion or root alcohol injection in trigeminal neuralgia.

    PubMed Central

    Sharr, M M; Garfield, J S

    1977-01-01

    Of 157 patients with trigeminal neuralgia, referred for neurosurgery, 81 underwent 85 ganglion or root injections. The results, which are analysed with regard to pain relief and sensory loss, compare favourably with results from the literature of other forms of surgery, particularly open temporal root section. PMID:886354

  12. Ganglion cell distribution and retinal resolution in the Florida manatee, Trichechus manatus latirostris.

    PubMed

    Mass, Alla M; Ketten, Darlene R; Odell, Daniel K; Supin, Alexander Ya

    2012-01-01

    The topographic organization of retinal ganglion cells was examined in the Florida manatee (Trichechus manatus latirostris) to assess ganglion cell size and distribution and to estimate retinal resolution. The ganglion cell layer of the manatee's retina was comprised primarily of large neurons with broad intercellular spaces. Cell sizes varied from 10 to 60 μm in diameter (mean 24.3 μm). The retinal wholemounts from adult animals measured 446-501 mm(2) in area with total ganglion cell counts of 62,000-81,800 (mean 70,200). The cell density changed across the retina, with the maximum in the area below the optic disc and decreasing toward the retinal edges and in the immediate vicinity of the optic disc. The maximum cell density ranged from 235 to 337 cells per millimeter square in the adult retinae. Two wholemounts obtained from juvenile animals were 271 and 282 mm(2) in area with total cell numbers of 70,900 and 68,700, respectively (mean 69,800), that is, nearly equivalent to those of adults, but juvenile retinae consequently had maximum cell densities that were higher than those of adults: 478 and 491 cells per millimeter square. Calculations indicate a retinal resolution of ∼19' (1.6 cycles per degree) in both adult and juvenile retinae. PMID:21964938

  13. Characterization of a putative acetylcholine receptor in chick ciliary ganglion neurons

    SciTech Connect

    Stollberg, J.

    1985-01-01

    Monoclonal antibodies to the main immunogenic region on the alpha subunit of acetylcholine receptors in muscle and electric organ recognize membrane components in chick brain and ciliary ganglia that are candidates for the neuronal receptor. The component in chick brain has been purified by immunoaffinity chromatography. It specifically binds nicotine but not alpha-bungarotoxin, and can be affinity labeled with (/sup 3/H)bromoacetylcholine. The cross-reacting component in ciliary ganglion neurons is concentrated in synaptic membrane, and can be modulated by exposure of the cells to cholinergic ligands in culture. The cross-reacting component in ciliary ganglion neurons is an integral membrane component that binds concanavalin A, and it is distinct from the alpha-bungarotoxin binding component. The acetylcholine receptor function in these neurons can be locked by affinity alkylation with bromoacetylcholine, indicating similarity in this respect to receptors from muscle and electric organ. Antisera raised against the partially purified component from chick brain also block receptor function on ciliary ganglion neurons. The subcellular distribution of the ganglion component in culture is assessed, and it is shown that approximately 2/3 of the cross-reacting components are intracellular; the majority of these seem not to be destined for insertion into the plasma membrane.

  14. Noise-Induced Neural Degeneration and Therapeutic Effect of Antioxidant Drugs

    PubMed Central

    Choi, Seong Hee

    2015-01-01

    The primary site of lesion induced by noise exposure is the hair cells in the organ of Corti and the primary neural degeneration occurs in synaptic terminals of cochlear nerve fibers and spiral ganglion cells. The cellular basis of noise-induced hearing loss is oxidative stress, which refers to a severe disruption in the balance between the production of free radicals and antioxidant defense system in the cochlea by excessive production of free radicals induced by noise exposure. Oxidative stress has been identified by a variety of biomarkers to label free radical activity which include four-hydroxy-2-nonenal, nitrotyrosine, and malondialdehyde, and inducible nitric oxide synthase, cytochrome-C, and cascade-3, 8, 9. Furthermore, oxidative stress is contributing to the necrotic and apoptotic cell deaths in the cochlea. To counteract the known mechanisms of pathogenesis and oxidative stress induced by noise exposure, a variety of antioxidant drugs including oxygen-based antioxidants such as N-acetyl-L-cystein and acetyl-L-carnitine and nitrone-based antioxidants such as phenyl-N-tert-butylnitrone (PBN), disufenton sodium, 4-hydroxy PBN, and 2, 4-disulfonyl PBN have been used in our laboratory. These antioxidant drugs were effective in preventing or treating noise-induced hearing loss. In combination with other antioxidants, antioxidant drugs showed a strong synergistic effect. Furthermore, successful use of antioxidant drugs depends on the optimal timing of treatment and the duration of treatment, which are highly related to the time window of free radical formation induced by noise exposure. PMID:26771008

  15. Noise-Induced Neural Degeneration and Therapeutic Effect of Antioxidant Drugs.

    PubMed

    Choi, Seong Hee; Choi, Chul-Hee

    2015-12-01

    The primary site of lesion induced by noise exposure is the hair cells in the organ of Corti and the primary neural degeneration occurs in synaptic terminals of cochlear nerve fibers and spiral ganglion cells. The cellular basis of noise-induced hearing loss is oxidative stress, which refers to a severe disruption in the balance between the production of free radicals and antioxidant defense system in the cochlea by excessive production of free radicals induced by noise exposure. Oxidative stress has been identified by a variety of biomarkers to label free radical activity which include four-hydroxy-2-nonenal, nitrotyrosine, and malondialdehyde, and inducible nitric oxide synthase, cytochrome-C, and cascade-3, 8, 9. Furthermore, oxidative stress is contributing to the necrotic and apoptotic cell deaths in the cochlea. To counteract the known mechanisms of pathogenesis and oxidative stress induced by noise exposure, a variety of antioxidant drugs including oxygen-based antioxidants such as N-acetyl-L-cystein and acetyl-L-carnitine and nitrone-based antioxidants such as phenyl-N-tert-butylnitrone (PBN), disufenton sodium, 4-hydroxy PBN, and 2, 4-disulfonyl PBN have been used in our laboratory. These antioxidant drugs were effective in preventing or treating noise-induced hearing loss. In combination with other antioxidants, antioxidant drugs showed a strong synergistic effect. Furthermore, successful use of antioxidant drugs depends on the optimal timing of treatment and the duration of treatment, which are highly related to the time window of free radical formation induced by noise exposure. PMID:26771008

  16. Identification of AⅡ amacrine, displaced amacrine, and bistratified ganglion cell types in human retina with antibodies against calretinin.

    PubMed

    Lee, Sammy C S; Weltzien, Felix; Madigan, Michele C; Martin, Paul R; Grünert, Ulrike

    2016-01-01

    Antibodies against calretinin are markers for one type of rod pathway interneuron (AⅡ amacrine cell) in the retina of some but not all mammalian species. The AⅡ cells play a crucial role in night-time (scotopic) vision and have been proposed as a target for optogenetic restoration of vision in retinal disease. In the present study we aimed to characterize the AⅡ cells in human retina. Postmortem human donor eyes were obtained with ethical approval and processed for calretinin immunofluorescence. Calretinin-positive somas in the inner nuclear and the ganglion cell layer were filled with the lipophilic dye DiI. The large majority (over 80%) of calretinin-immunoreactive cells is located in the inner nuclear layer, is immunopositive for glycine transporter 1, and shows the typical morphology of AⅡ amacrine cells. In addition, a small proportion of calretinin-positive cells in the inner nuclear layer and in the ganglion cell layer is glutamic acid decarboxylase-positive and shows the morphology of widefield amacrine cells (stellate, semilunar, and thorny amacrine cells). About half of the calretinin cells in the ganglion cell layer are bistratified ganglion cells resembling the small bistratified (presumed blue-ON/yellow-OFF) and the G17 ganglion cell previously described in primates. We conclude that in human retina, antibodies against calretinin can be used to identify AⅡ amacrine cells in the inner nuclear layer as well as widefield amacrine and small bistratified ganglion cells in the ganglion cell layer. PMID:26053777

  17. Differential modulation of retinal ganglion cell light responses by orthosteric and allosteric metabotropic glutamate receptor 8 compounds

    PubMed Central

    Reed, Brian T.; Morgans, Catherine W.; Duvoisin, Robert M.

    2012-01-01

    To investigate the role of mGluR8 in modulating the synaptic responses of retinal ganglion cells, we used a recently identified positive allosteric modulator of mGluR8, AZ12216052 (AZ) and the mGluR8-specific orthosteric agonist (S)-3,4-dicarboxyphenylglycine (DCPG). These agents were applied to whole-cell voltage-clamped ganglion cells from an isolated, superfused mouse retina preparation. DCPG reduced OFF-ganglion cell excitatory currents, whereas AZ enhanced the peak excitatory currents in ON-, OFF-, and ON-OFF-ganglion cells. The effects on ganglion cell inhibitory currents were more varied. The effects of the allosteric modulator were stronger for bright stimuli than for dim stimuli, consistent with receptor stimulation by endogenous glutamate being stronger during bright light stimulation and with mGluR8 receptors mainly being localized away from glutamate release sites, immuno-labeled with VGLUT1. The differential sensitivity of ganglion cell light responses to DCPG and AZ supports multiple sites where mGluR8 modulates the light responses of ganglion cells. PMID:23164615

  18. An excitatory amacrine cell detects object motion and provides feature-selective input to ganglion cells in the mouse retina

    PubMed Central

    Kim, Tahnbee; Soto, Florentina; Kerschensteiner, Daniel

    2015-01-01

    Retinal circuits detect salient features of the visual world and report them to the brain through spike trains of retinal ganglion cells. The most abundant ganglion cell type in mice, the so-called W3 ganglion cell, selectively responds to movements of small objects. Where and how object motion sensitivity arises in the retina is incompletely understood. In this study, we use 2-photon-guided patch-clamp recordings to characterize responses of vesicular glutamate transporter 3 (VGluT3)-expressing amacrine cells (ACs) to a broad set of visual stimuli. We find that these ACs are object motion sensitive and analyze the synaptic mechanisms underlying this computation. Anatomical circuit reconstructions suggest that VGluT3-expressing ACs form glutamatergic synapses with W3 ganglion cells, and targeted recordings show that the tuning of W3 ganglion cells' excitatory input matches that of VGluT3-expressing ACs' responses. Synaptic excitation of W3 ganglion cells is diminished, and responses to object motion are suppressed in mice lacking VGluT3. Object motion, thus, is first detected by VGluT3-expressing ACs, which provide feature-selective excitatory input to W3 ganglion cells. DOI: http://dx.doi.org/10.7554/eLife.08025.001 PMID:25988808

  19. Observations on the mode of action of some central depressant drugs on transmission through the cat superior cervical ganglion

    PubMed Central

    Brown, D. A.; Quilliam, J. P.

    1964-01-01

    Methylpentynol, paraldehyde, amylobarbitone and procainamide blocked transmission through the cat superior cervical ganglion, and antagonized the ganglion-stimulating actions of acetylcholine and carbachol injected intra-arterially to the ganglion. Comparison with the effects of tetraethylammonium indicated that the impaired response to acetylcholine could not wholly account for the failure of transmission, which suggested that an impaired release of transmitter substance was a contributory factor. Methylpentynol, paraldehyde and procainamide also blocked the ganglion-stimulating action of potassium chloride. In contrast, amylobarbitone and pentobarbitone did not block the stimulating action of potassium chloride, but antagonized specifically the actions of acetylcholine and carbachol. The anti-acetylcholine activities of the two barbiturate drugs at this site accord with their relative ganglion-blocking activities. It is concluded that the ganglion-blocking action of methylpentynol, paraldehyde and procainamide arises from a nonspecific depression of both presynaptic and postsynaptic elements in the ganglion, but that barbiturate compounds act more specifically on the acetylcholine receptor. PMID:14228128

  20. Elevation of intracellular calcium levels in spiral ganglion cells by trimethyltin.

    PubMed

    Fechter, L D; Liu, Y

    1995-11-01

    The neurotoxicant, trimethyltin (TMT) produces cochlear impairment at far lower dose levels and far more rapidly than it does central nervous system effects. The initial effects of TMT in the cochlea, in vivo, are consistent with disruption of the inner hair cell type-1 spiral ganglion cell synapse although it is uncertain whether the effect is on presynaptic and/or postsynaptic units. This synapse is believed to be an excitatory glutamatergic one, providing the possibility that TMT could induce an excitotoxic process resulting in elevations in intracellular calcium ([Ca2+]i). The objective of this study was to determine whether TMT had direct toxic effects on the postsynaptic spiral ganglion cells studied in primary culture and to identify the role of extracellular calcium in such an effect. The marker of interest was the effect of this agent on [Ca2+]i levels as determined using quantitation of the fluorescent calcium dye, Fura-2. TMT did induce a marked and sustained elevation in [Ca2+]i level in the spiral ganglion cells that appeared to have a rapid initial phase and a slower saturating phase. Studies performed using calcium-free medium showed that elevation of [Ca2+]i in spiral ganglion cells by TMT was attenuated but not entirely blocked. Further, the L-type calcium channel blocker, nifedipine, was able to inhibit the initial increase in [Ca2+]i, suggesting that at least this phase of the TMT effect was mediated by calcium channels, although nifedipine had no significant effect on the time to reach the maximal [Ca2+]i level. Parallel control experiments performed using application of exogenous glutamate and depolarizing K+ concentrations also produced elevation in [Ca2+]i levels. The data indicate that TMT elevates [Ca2+]i in isolated spiral ganglion cells both by increasing extracellular uptake via Ca2+ channels and also by releasing Ca2+ from intracellular stores. Thus TMT ototoxicity appears to include a direct postsynaptic toxic event. PMID:8647712