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Nichterwitz S, Nijssen J, Storvall H, Schweingruber C, Comley LH, Allodi I, Lee MVD, Deng Q, Sandberg R, Hedlund E. LCM-seq reveals unique transcriptional adaptation mechanisms of resistant neurons and identifies protective pathways in spinal muscular atrophy. Genome Res 2020; 30:1083-1096. [PMID: 32820007 PMCID: PMC7462070 DOI: 10.1101/gr.265017.120] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2020] [Accepted: 07/10/2020] [Indexed: 11/25/2022]
Abstract
Somatic motor neurons are selectively vulnerable in spinal muscular atrophy (SMA), which is caused by a deficiency of the ubiquitously expressed survival of motor neuron protein. However, some motor neuron groups, including oculomotor and trochlear (ocular), which innervate eye muscles, are for unknown reasons spared. To reveal mechanisms of vulnerability and resistance in SMA, we investigate the transcriptional dynamics in discrete neuronal populations using laser capture microdissection coupled with RNA sequencing (LCM-seq). Using gene correlation network analysis, we reveal a TRP53-mediated stress response that is intrinsic to all somatic motor neurons independent of their vulnerability, but absent in relatively resistant red nucleus and visceral motor neurons. However, the temporal and spatial expression analysis across neuron types shows that the majority of SMA-induced modulations are cell type-specific. Using Gene Ontology and protein network analyses, we show that ocular motor neurons present unique disease-adaptation mechanisms that could explain their resilience. Specifically, ocular motor neurons up-regulate (1) Syt1, Syt5, and Cplx2, which modulate neurotransmitter release; (2) the neuronal survival factors Gdf15, Chl1, and Lif; (3) Aldh4, that protects cells from oxidative stress; and (4) the caspase inhibitor Pak4. Finally, we show that GDF15 can rescue vulnerable human spinal motor neurons from degeneration. This confirms that adaptation mechanisms identified in resilient neurons can be used to reduce susceptibility of vulnerable neurons. In conclusion, this in-depth longitudinal transcriptomics analysis in SMA reveals novel cell type-specific changes that, alone and combined, present compelling targets, including Gdf15, for future gene therapy studies aimed toward preserving vulnerable motor neurons.
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Affiliation(s)
| | - Jik Nijssen
- Department of Neuroscience, Karolinska Institutet, 171 77 Stockholm, Sweden
| | - Helena Storvall
- Department of Cell and Molecular Biology, Karolinska Institutet, 171 77 Stockholm, Sweden
- Ludwig Institute for Cancer Research, Karolinska Institutet, 171 77 Stockholm, Sweden
| | | | - Laura Helen Comley
- Department of Neuroscience, Karolinska Institutet, 171 77 Stockholm, Sweden
| | - Ilary Allodi
- Department of Neuroscience, Karolinska Institutet, 171 77 Stockholm, Sweden
| | - Mirjam van der Lee
- Department of Neuroscience, Karolinska Institutet, 171 77 Stockholm, Sweden
| | - Qiaolin Deng
- Ludwig Institute for Cancer Research, Karolinska Institutet, 171 77 Stockholm, Sweden
| | - Rickard Sandberg
- Department of Cell and Molecular Biology, Karolinska Institutet, 171 77 Stockholm, Sweden
- Ludwig Institute for Cancer Research, Karolinska Institutet, 171 77 Stockholm, Sweden
| | - Eva Hedlund
- Department of Neuroscience, Karolinska Institutet, 171 77 Stockholm, Sweden
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Sumner-Rooney L, Kenny NJ, Ahmed F, Williams ST. The utility of micro-computed tomography for the non-destructive study of eye microstructure in snails. Sci Rep 2019; 9:15411. [PMID: 31659206 PMCID: PMC6817935 DOI: 10.1038/s41598-019-51909-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Accepted: 10/09/2019] [Indexed: 02/02/2023] Open
Abstract
Molluscan eyes exhibit an enormous range of morphological variation, ranging from tiny pigment-cup eyes in limpets, compound eyes in ark clams and pinhole eyes in Nautilus, through to concave mirror eyes in scallops and the large camera-type eyes of the more derived cephalopods. Here we assess the potential of non-destructive micro-computed tomography (µ-CT) for investigating the anatomy of molluscan eyes in three species of the family Solariellidae, a group of small, deep-sea gastropods. We compare our results directly with those from traditional histological methods applied to the same specimens, and show not only that eye microstructure can be visualised in sufficient detail for meaningful comparison even in very small animals, but also that μ-CT can provide additional insight into gross neuroanatomy without damaging rare and precious specimens. Data from μ-CT scans also show that neurological innervation of eyes is reduced in dark-adapted snails when compared with the innervation of cephalic tentacles, which are involved in mechanoreception and possibly chemoreception. Molecular tests also show that the use of µ-CT and phosphotungstic acid stain do not prevent successful downstream DNA extraction, PCR amplification or sequencing. The use of µ-CT methods is therefore highly recommended for the investigation of difficult-to-collect or unique specimens.
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Affiliation(s)
| | | | - Farah Ahmed
- Natural History Museum, Cromwell Road, London, UK
- Exponent International Ltd, London, UK
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3
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Gilbert AR, Chévez-Barrios P, Cykowski MD. Perineurial-like Cells and EMA Expression in the Suprachoroidal Region of the Human Eye. J Histochem Cytochem 2018; 66:367-375. [PMID: 29446690 PMCID: PMC5958356 DOI: 10.1369/0022155418756308] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Accepted: 01/02/2018] [Indexed: 11/22/2022] Open
Abstract
The suprachoroidal region of the eye comprises vascular channels, melanocytes, and thin fibroblasts with elongated cytoplasm that are positioned directly adjacent to the densely collagenous sclera. Morphological similarities between these suprachoroidal fibroblasts and arachnoid cells and perineurial cells have been recognized, but whether these fibroblasts have a perineurial cell-like immunophenotype is not known. To further examine the relationship of these three cell types, we investigated the comparative expression of epithelial membrane antigen (EMA), the tight junction protein claudin-1, glucose transporter-1 (Glut-1), and CD34 in suprachoroidal fibroblasts, arachnoid of the optic nerve sheath, and perineurium of ciliary nerves in eight human eye specimens. Granular, diffuse, and cytoplasmic EMA expression was seen in suprachoroidal fibroblasts, but this was not contiguous with the similar pattern of EMA expression in adjacent perineurium and arachnoid. CD34 expression in suprachoroidal fibroblasts was also seen, similar to arachnoid and perineurium. Claudin-1 and Glut-1 were not consistently expressed in suprachoroidal fibroblasts, distinguishing them from perineurial cells in particular and suggesting that these fibroblasts do not arise directly from adjacent arachnoid or perineurium. Nonetheless, the overlapping morphology and protein expression suggest phenotypic similarities in these cells that protect and support adjacent retina, optic nerve, and peripheral nerve.
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Affiliation(s)
- Andrea R. Gilbert
- Department of Pathology, UT Health San Antonio,
San Antonio, Texas
- Department of Pathology and Genomic Medicine,
Houston Methodist Hospital, Houston, Texas
| | - Patricia Chévez-Barrios
- Department of Pathology and Genomic Medicine,
Houston Methodist Hospital, Houston, Texas
- Department of Ophthalmology, Blanton Eye
Institute, Houston Methodist Hospital, Houston, Texas
- Departments of Pathology and Laboratory
Medicine, Weill Cornell Medicine, New York City, New York
- Ophthalmology, Weill Cornell Medicine, New York
City, New York
| | - Matthew D. Cykowski
- Department of Pathology and Genomic Medicine,
Houston Methodist Hospital, Houston, Texas
- Departments of Pathology and Laboratory
Medicine, Weill Cornell Medicine, New York City, New York
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4
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Sitko AA, Kuwajima T, Mason C. Eye-specific segregation and differential fasciculation of developing retinal ganglion cell axons in the mouse visual pathway. J Comp Neurol 2018; 526:1077-1096. [PMID: 29322522 PMCID: PMC6062437 DOI: 10.1002/cne.24392] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Revised: 12/22/2017] [Accepted: 01/02/2018] [Indexed: 01/19/2023]
Abstract
Prior to forming and refining synaptic connections, axons of projection neurons navigate long distances to their targets. While much is known about guidance cues for axon navigation through intermediate choice points, whether and how axons are organized within tracts is less clear. Here we analyze the organization of retinal ganglion cell (RGC) axons in the developing mouse retinogeniculate pathway. RGC axons are organized by both eye-specificity and topography in the optic nerve and tract: ipsilateral RGC axons are segregated from contralateral axons and are offset laterally in the tract relative to contralateral axon topographic position. To identify potential cell-autonomous factors contributing to the segregation of ipsilateral and contralateral RGC axons in the visual pathway, we assessed their fasciculation behavior in a retinal explant assay. Ipsilateral RGC neurites self-fasciculate more than contralateral neurites in vitro and maintain this difference in the presence of extrinsic chiasm cues. To further probe the role of axon self-association in circuit formation in vivo, we examined RGC axon organization and fasciculation in an EphB1-/- mutant, in which a subset of ipsilateral RGC axons aberrantly crosses the midline but targets the ipsilateral zone in the dorsal lateral geniculate nucleus on the opposite side. Aberrantly crossing axons retain their association with ipsilateral axons in the contralateral tract, indicating that cohort-specific axon affinity is maintained independently of guidance signals present at the midline. Our results provide a comprehensive assessment of RGC axon organization in the retinogeniculate pathway and suggest that axon self-association contributes to pre-target axon organization.
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Affiliation(s)
- Austen A. Sitko
- Departments of Neuroscience, and Ophthalmology, College of Physicians and Surgeons, Columbia University, New York, New York, 10032
- Current address, corresponding author: Austen A. Sitko, Department of Neurobiology, Harvard Medical School, 456 Goldenson, 220 Longwood Avenue, Boston, MA 02115,
| | - Takaaki Kuwajima
- Departments of Neuroscience, and Ophthalmology, College of Physicians and Surgeons, Columbia University, New York, New York, 10032
- Pathology and Cell Biology, and Ophthalmology, College of Physicians and Surgeons, Columbia University, New York, New York, 10032
| | - Carol Mason
- Departments of Neuroscience, and Ophthalmology, College of Physicians and Surgeons, Columbia University, New York, New York, 10032
- Pathology and Cell Biology, and Ophthalmology, College of Physicians and Surgeons, Columbia University, New York, New York, 10032
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Abstract
PURPOSE To study the distribution and mechanism of traumatic injuries to the nerves supplying the eye and muscles protecting the visual apparatus. METHODS Brain autopsy was carried out in 12 consecutive patients who died within three days after closed head injury. A segment of the brainstem with the entire intracranial portion of nerves II-VII was dissected out in each case and fixed in formalin. The specimens were stripped of the leptomeninges and inspected thoroughly under magnification. RESULTS Injuries to the nerves were seen in nine subjects. The oculomotor nerve was completely torn off from the midbrain unilaterally in three and bilaterally in two cases. In one patient only a portion of the superficial fibres on the medial aspect of the nerve was ripped out from the brainstem. In two patients the fourth nerve was ruptured. The root of the fifth cranial nerve was contused and the fibres between the brainstem and Gasserian ganglion crushed and separated in one case. Bilateral avulsion of the root of the sixth nerve from the brainstem was found in two cases. The initial segment of the facial nerve was crushed in two subjects. No visible injury to the optic nerves was found. CONCLUSIONS Cranial nerves related to the visual system are subject to serious injury in a large proportion of cases of severe head trauma resulting from automobile accidents. In the majority of cases damage results from ripping the roots of these nerves out of the brainstem.
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Affiliation(s)
- Z Mariak
- Department of Ophthalmology, University Medical School, Bialystok, Poland
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6
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Musk GC, King M, He B. Horner Syndrome in 2 Pigs ( Sus scrofa) after Vascular Grafting of the Carotid Artery and Jugular Vein. Comp Med 2017; 67:518-523. [PMID: 29212584 PMCID: PMC5713167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Revised: 03/23/2017] [Accepted: 07/14/2017] [Indexed: 06/07/2023]
Abstract
The term Horner syndrome refers to the clinical presentation of oculosympathoparesis, comprising miosis, ptosis, and facial anhydrosis. To date, there are 2 reports of postoperative Horner syndrome in pigs. In this species the cervical sympathetic chain and cranial cervical sympathetic ganglion are consistently within the carotid artery sheath. This case study describes the sudden onset of Horner syndrome in 2 pigs, from a study cohort of 8, after the placement of a vascular graft between the carotid artery and external jugular vein. Anesthesia and surgery was uneventful in all the pigs in the study, but 2 pigs demonstrated clinical signs including ptosis, enophthalmos and prolapse of the nictitating membrane immediately after recovery from anesthesia. Horner syndrome was diagnosed in light of the clinical signs. These clinical signs persisted throughout the 2-mo study period and did not appear to improve or deteriorate in that time. Gross examination of the surgery site at the end of the study did not reveal an obvious lesion in the carotid artery sheath. The risk of Horner syndrome after surgery involving the carotid artery in pigs had not been reported prior to this study. Without specific measures to protect the cervical sympathetic ganglion during surgery, the incidence of postoperative Horner syndrome was 25% in our population of pigs. Although the welfare implications of this syndrome are minimal, concerted effort to avoid intraoperative damage to the cervical ganglion is essential for future work.
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Affiliation(s)
- Gabrielle C Musk
- Animal Care Services, University of Western Australia, Crawley, Australia;,
| | - Martyn King
- Perth Animal Eye Hospital, Perth, Western Australia, Australia
| | - Bulang He
- School of Surgery, University of Western Australia, Crawley, Australia
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7
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Affiliation(s)
- Andrew Malem
- Eye Department, Queen Alexandra Hospital, Southwick Hill Road, Portsmouth, UK
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8
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Veselovskaya NM, Veselovskaya ZF, Zherebko IB. [EFFICACY OF COMBINED MICROSURGICAL TECHNIQUE IN SEVERE TRAUMATIC INJURY OF EYEBALL]. Klin Khir 2017:48-51. [PMID: 30272916] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Analysis of clinical and functional results of microsurgical restoration of eyeball in remote terms after primary surgical processing for traumatic injury of eyes, using combined one-stage operative intervention on anterior and posterior segments, was presented. Satisfactory result was achieved in 56.4% injured persons, in 43.6% - functional outcome after the operation, concerning perspectives of further restoration of optic functions, have appeared unsatisfactory.
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9
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Owidzka M, Laudanska-Olszewska I, Omulecki W. Contrast sensitivity assessment in primary open angle glaucoma and ocular hypertension. Klin Oczna 2016; 118:7-10. [PMID: 29715400] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
INTRODUCTION Contrast sensitivity assessment is an important additional examination, which enables the full insight into the patient's quality of vision, and early diagnosis of visual disturbances. MATERIAL AND METHODS Forty six patients (92 eyes) with primary open angle glaucoma or ocular hypertension were enrolled in the study. The enrolment criteria were full or almost full visual acuity and the patients with visual field defects or any other ocular disease were excluded. Contrast sensitivity was assessed both under photopic and mesopic conditions (with and without glare) using the Functional Vision Analyzer separately for each eye. Furthermore, the retinal nerve fiber layer (RNFL) thickness was measured using scanning laser polarimetry (GDx). RESULTS Contrast sensitivity was significantly reduced under both mesopic and photopic conditions in patients with primary open angle glaucoma or ocular hypertension. CONCLUSIONS Evaluation of contrast sensitivity is a valuable diagnostic test, which enables the assessment of visual dysfunction in patients with primary open angle glaucoma or ocular hypertension persisting despite good visual acuity.
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10
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Abstract
Visual neuroscience is considered to be a contemporary concern, based in large part on relating characteristics of neural functioning to visual experience. It presupposes a detailed knowledge of neural activity for which the neuron doctrine is a fundamental tenet. However, long before either the neuron doctrine had been advanced or the nerve cell had been described, attempts were made to estimate the dimensions of nerve fibres from measures of visual resolution. In the seventeenth century, the microscopes of Hooke and van Leeuwenhoek were unable to resolve structures as small as nerves adequately. However, it was not Hooke's microscope that led to an estimate of the dimensions of nerve fibres but his experiments on the limits of visual resolution. Hooke determined that a separation of one minute of arc was the minimum that could normally be seen. Descartes had earlier speculated that the retina consisted of the terminations of fibres of the optic nerve, and that their size defined the limits of what could be seen. Estimates of the diameters of nerve fibres were made on the basis of human visual acuity by Porterfield in 1738; he calculated the diameters of nerve fibres in the retina as one 7200th part of an inch (0.0035 mm), based on the resolution of one minute of arc as the minimum visible. In the same year, Jurin questioned the reliability of such estimates because of variations in visual resolution with different stimuli. The measurement of visual acuity was refined by Mayer in 1755, with dots, gratings, and grids used as stimuli. In the 1830s, Treviranus fused the microscopic and acuity approaches to determine the dimensions of nerve fibres. His indirect estimates of the dimensions of retinal fibres were close to those derived from microscopic observation. However, the suggestion that the retina consisted of terminations of nerve fibres influenced his detailed illustrations of its microscopic structure. Contrary to the situation that obtained after the microscopic structure of the retina had been established, a function of vision (acuity) was used to determine the dimensions of the structures (retinal elements) that were thought to mediate it.
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Affiliation(s)
- Nicholas J Wade
- Department of Psychology, University of Dundee, Dundee DD1 4HN, Scotland, UK.
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11
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Lazarenko VI, Kadantseva AS, Savchenkov YI, Shatilova RI. [Patterns of ocular neurovascular reactions]. Vestn Oftalmol 2016; 132:26-31. [PMID: 27456561 DOI: 10.17116/oftalma2016132326-31] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
AIM To examine factors and determinants of ocular neurovascular reactions (NVR). MATERIAL AND METHODS The study included 120 healthy participants of both sexes aged 20.9±0.6 years, who underwent a standard ophthalmic examination. Ocular microcirculation was recorded using laser Doppler flowmetry. Autonomic homeostasis and the intensity of slow-wave oscillations of hemodynamics were of interest. Autoregulation of cerebral blood flow was assessed by transcranial color-coded duplex scanning. RESULTS The dynamics of perfusion control mechanisms (myogenic and neurogenic) have been studied in the young healthy population of Krasnoyarsk. The role of the autonomic nervous system in initiating a particular type of ocular NVR has been identified. The authors have also determined the significance of the nitric oxide production intensity in different types of NVR. CONCLUSION The type of ocular NVR is determined by parameters of cerebral hemodynamics. Normotonic NVR is associated with effective autoregulation of cerebral blood flow, while hyper- and hypotonic types of reactions - with autoregulatory failure.
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Affiliation(s)
- V I Lazarenko
- Krasnoyarsk State Medical University named after prof. V.F. Voyno-Yasenetsky, 1 Partizana Zeleznyaka St., Krasnoyarsk, Russian Federation, 660022
| | - A S Kadantseva
- Krasnoyarsk regional ophthalmological clinical hospital named after prof. P.G. Makarov, 1v Nikitina St., Krasnoyarsk, Russian Federation, 660022
| | - Yu I Savchenkov
- Krasnoyarsk State Medical University named after prof. V.F. Voyno-Yasenetsky, 1 Partizana Zeleznyaka St., Krasnoyarsk, Russian Federation, 660022
| | - R I Shatilova
- Krasnoyarsk State Medical University named after prof. V.F. Voyno-Yasenetsky, 1 Partizana Zeleznyaka St., Krasnoyarsk, Russian Federation, 660022
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12
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Martín-Buro MC, Garcés P, Maestú F. Test-retest reliability of resting-state magnetoencephalography power in sensor and source space. Hum Brain Mapp 2016; 37:179-90. [PMID: 26467848 PMCID: PMC6867588 DOI: 10.1002/hbm.23027] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Revised: 09/19/2015] [Accepted: 09/29/2015] [Indexed: 01/18/2023] Open
Abstract
Several studies have reported changes in spontaneous brain rhythms that could be used as clinical biomarkers or in the evaluation of neuropsychological and drug treatments in longitudinal studies using magnetoencephalography (MEG). There is an increasing necessity to use these measures in early diagnosis and pathology progression; however, there is a lack of studies addressing how reliable they are. Here, we provide the first test-retest reliability estimate of MEG power in resting-state at sensor and source space. In this study, we recorded 3 sessions of resting-state MEG activity from 24 healthy subjects with an interval of a week between each session. Power values were estimated at sensor and source space with beamforming for classical frequency bands: delta (2-4 Hz), theta (4-8 Hz), alpha (8-13 Hz), low beta (13-20 Hz), high beta (20-30 Hz), and gamma (30-45 Hz). Then, test-retest reliability was evaluated using the intraclass correlation coefficient (ICC). We also evaluated the relation between source power and the within-subject variability. In general, ICC of theta, alpha, and low beta power was fairly high (ICC > 0.6) while in delta and gamma power was lower. In source space, fronto-posterior alpha, frontal beta, and medial temporal theta showed the most reliable profiles. Signal-to-noise ratio could be partially responsible for reliability as low signal intensity resulted in high within-subject variability, but also the inherent nature of some brain rhythms in resting-state might be driving these reliability patterns. In conclusion, our results described the reliability of MEG power estimates in each frequency band, which could be considered in disease characterization or clinical trials.
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Affiliation(s)
- María Carmen Martín-Buro
- Laboratory of Cognitive and Computational Neuroscience, Centre for Biomedical Technology, Madrid, Spain
- Psychology Division, Cardenal Cisneros University College, Complutense University of Madrid, Spain
- Biomedical Research Networking Center in Bioengineering Biomaterials and Nanomedicine (CIBER-BBN), Madrid, Spain
| | - Pilar Garcés
- Laboratory of Cognitive and Computational Neuroscience, Centre for Biomedical Technology, Madrid, Spain
- Biomedical Research Networking Center in Bioengineering Biomaterials and Nanomedicine (CIBER-BBN), Madrid, Spain
- Department of Applied Physics III, Faculty of Physics, Complutense University of Madrid, Spain
| | - Fernando Maestú
- Laboratory of Cognitive and Computational Neuroscience, Centre for Biomedical Technology, Madrid, Spain
- Biomedical Research Networking Center in Bioengineering Biomaterials and Nanomedicine (CIBER-BBN), Madrid, Spain
- Department of Basic Psychology II, Faculty of Psychology, Complutense University of Madrid, Spain
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13
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Guo Y, Xie Q, Liu B. [Case of exacerbation of ophthalmic branch of trigeminal nerve herpes zoster caused by taking american ginseng]. Zhongguo Zhen Jiu 2015; 35:1020. [PMID: 26790210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
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14
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Ghosh S, Avadhany ST. Effects of physical activity on pupil cycle time (PCT) in healthy Indian male. Indian J Physiol Pharmacol 2014; 58:262-270. [PMID: 25906609] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Globally, physical inactivity is an important risk factor for the development of non-communicable disease consisting of coronary artery disease, as well as, other diseases including hypertension, diabetes, obesity, osteoporosis, and certain types of cancers. Parasympathetic nervous system (PNS) activity in the eye is determined by the pupil cycle time (PCT) can be comparable with cardiac parasympathetic response and thereby determine the morbidity and mortality among individuals. The PCT is measured by throwing white light on the edge of the pupil. Pupil cycling is a feature of pupillary reflex arc. The aim of this study is to establish the effect of physical activity on the PCT. The counting of PCT was done for 90 cycles and average one count is considered a single PCT. The physical activity level (PAL) was determined by administering a physical activity level questionnaire developed in the Division of Nutrition, St. John's Medical College, Bangalore. The PAL is classified as < 1.4 as sedentary, 1.55 to 1.75 moderately active, and > 1.75 heavily active. Thirty healthy male volunteers in the age group of 18-50 years and with BMI of 18.5 kg/m2-30 kg/m2 were studied. We obtained PCT of 962.00 ± 105.72 msec in sedentary, 896.77 ± 85.88 msec in moderately active and 889.45 ± 68.71 msec in heavily active individuals. Linear regression analysis shows there is statistically significant difference between the three different groups of physical activity level with a b value of 0 and R2 being 0.19. Increase in physical activity led to decrease in the PCT i.e. increase in the parasympathetic tone in the eye. Pupil cycle time (PCT) is a simple noninvasive tool to assess and differentiate the PNS function in different activity level of individual.
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15
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Colebatch JG, Dennis DL, Govender S, Chen P, Todd NPM. Recruitment properties and significance of short latency reflexes in neck and eye muscles evoked by brief lateral head accelerations. Exp Brain Res 2014; 232:2977-88. [PMID: 24838556 PMCID: PMC4131169 DOI: 10.1007/s00221-014-3980-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2014] [Accepted: 04/28/2014] [Indexed: 11/16/2022]
Abstract
Short lateral head accelerations were applied to investigate the recruitment properties of the reflexes underlying the earliest ocular and cervical electromyographic reflex responses to these disturbances. Components of both reflexes are vestibular dependent and have been termed “ocular vestibular evoked myogenic potentials” and “cervical vestibular evoked myogenic potentials”, respectively. Previous investigations using a unilateral vestibular stimulus have indicated that some but not all these vestibular-dependent reflexes show a simple power law relationship to stimulus intensity. In particular, crossed otolith-ocular reflexes showed evidence of an inflection separating two types of behaviour. The present stimulus acts bilaterally, and only the earliest crossed otolith-ocular reflex, previously shown to have a strictly unilateral origin, showed evidence of an inflection. Reflex changes in ocular torsion could, in principle, correct for the changes associated with translation for an elevated eye, but our findings indicated that the responses were consistent with previous reports of tilt-type reflexes. For the neck, both vestibular and segmental (muscle spindle) reflexes were evoked and followed power law relationships, without any clear separation in sensitivity. Our findings are consistent with previous evidence of “tilt-like” reflexes evoked by lateral acceleration and suggest that the departure from a power law occurs as a consequence of a unilateral crossed pathway. For the neck, responses to transients are likely to always consist of both vestibular and non-vestibular (segmental) components. Most of the translation-evoked ocular and cervical reflexes appear to follow power law relationship to stimulus amplitude over a physiological range.
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Affiliation(s)
- James G Colebatch
- Prince of Wales Clinical School and Neuroscience Research Australia, University of New South Wales, Randwick, Sydney, NSW, 2052, Australia,
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16
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Abstract
The crustacean male-specific androgenic hormone is widely accepted as a key factor in sexual differentiation and in the development of secondary sex characteristics. However, the mechanism by which the plethora of different reproductive strategies are controlled and executed in crustaceans is not known. We discovered in the blue crab, Callinectes sapidus, a hitherto unknown neurohormone, named crustacean female sex hormone (CFSH), in distinct neurosecretory cells in the eyestalk ganglia. CFSH is highly expressed in females but weakly in males, and its crucial role in developing adult female phenotypes has now been established. CFSH cDNA encodes a 225-amino acid (aa) novel protein composed of a 23-aa predicted signal peptide, 33-aa precursor-related peptide and 167-aa mature protein that did not match any other sequence in GenBank. CFSH RNA interference knockdown by multiple administrations of double-stranded RNA at the prepubertal stage causes abnormal development of brooding and mating systems upon puberty. These systems include a pair of gonopores and an egg attachment system for brooding, comprised of an enlarged semicircular abdomen and ovigerous setae. The ovigerous setae in CFSH knocked-down females were fewer and 50% shorter and the gonopores were either significantly smaller than those of controls, misplaced, or absent. We also identified CFSH in the green crab, Carcinus maenas, a species that shares a similar reproductive strategy with C. sapidus. Together, our data provide the first evidence for the presence of a female hormone in crustaceans and its importance in positively controlling anatomic features associated with brooding and mating systems. From an evolutionary standpoint, the endocrine control supporting a female-specific reproductive strategy, as previously described for many vertebrate species, has now been demonstrated for the first time in crustaceans.
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Affiliation(s)
- Nilli Zmora
- Institute of Marine and Environmental Technology, University of Maryland Baltimore County (N.Z.) and University of Maryland Center for Environmental Science (J.S.C.), Baltimore, Maryland 21202
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Galicia-Carreón J, Santacruz C, Hong E, Jiménez-Martínez MC. The ocular surface: from physiology to the ocular allergic diseases. Rev Alerg Mex 2013; 60:172-183. [PMID: 24912910] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/03/2023] Open
Abstract
Allergic conjunctivitis (AC) is an inflammation of the conjunctiva secondary to an immune response to exogenous antigens, usually called allergens. In fact, AC is a syndrome that involves the entire ocular surface, including conjunctiva, lids, cornea, and tear film. The signs and symptoms of AC have a meaningful effect on comfort and patient health, and could be influenced by environment, genetics and immune regulation mechanisms, all of which work together in a complex immunological homeostasis. Dysregulation in such immune responses could turn into a variety of ocular allergic diseases (OAD). This review describes some of the current understanding of cellular and molecular pathways involved in different OAD.
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Affiliation(s)
- Jorge Galicia-Carreón
- Departamento de Farmacobiología, Centro de Investigaciones Avanzadas, Instituto Politécnico Nacional, México, DF.
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18
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Lysenko OI, Malyshev AV. [Ocular signs in anterior and posterior cervical sympathetic syndrome]. Vestn Oftalmol 2013; 129:67-70. [PMID: 23650753] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Features of anatomy and morphological changes of cervical spine resulting in sympathetic innervation defects, blood supply deficiency and ocular symptoms are reviewed. Results of experimental and clinical studies showing correlation of sympathetic cervical ganglions irritation and ocular pathologic conditions are presented. Ocular involvement in neurologic changes in anterior and posterior cervical sympathetic syndrome are reviewed.
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Palte HD, Gayer S, Arrieta E, Scot Shaw E, Nose I, Lee E, Arheart KL, Dubovy S, Birnbach DJ, Parel JM. Are ultrasound-guided ophthalmic blocks injurious to the eye? A comparative rabbit model study of two ultrasound devices evaluating intraorbital thermal and structural changes. Anesth Analg 2012; 115:194-201. [PMID: 22504211 PMCID: PMC3381790 DOI: 10.1213/ane.0b013e318253622e] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND Since Atkinson's original description of retrobulbar block in 1936, needle-based anesthetic techniques have become integral to ophthalmic anesthesia. These techniques are unfortunately associated with rare, grave complications such as globe perforation. Ultrasound has gained widespread acceptance for peripheral nerve blockade, but its translation to ocular anesthesia has been hampered because sonic energy, in the guise of thermal or biomechanical insult, is potentially injurious to vulnerable eye tissue. The US Food and Drug Administration (FDA) has defined guidelines for safe use of ultrasound for ophthalmic examination, but most ultrasound devices used by anesthesiologists are not FDA-approved for ocular application because they generate excessive energy. Regulating agencies state that ultrasound examinations can be safely undertaken as long as tissue temperatures do not increase >1.5°C above physiological levels. METHODS Using a rabbit model, we investigated the thermal and mechanical ocular effects after prolonged ultrasonic exposure to single orbital- and nonorbital-rated devices. In a dual-phase study, aimed at detecting ocular injury, the eyes of 8 rabbits were exposed to continuous 10-minute ultrasound examinations from 2 devices: (1) the Sonosite Micromaxx (nonorbital rated) and (2) the Sonomed VuMax (orbital rated) machines. In phase I, temperatures were continuously monitored via thermocouples implanted within specific eye structures (n = 4). In phase II the eyes were subjected to ultrasonic exposure without surgical intervention (n = 4). All eyes underwent light microscopy examinations, followed at different intervals by histology evaluations conducted by an ophthalmic pathologist. RESULTS Temperature changes were monitored in the eyes of 4 rabbits. The nonorbital-rated transducer produced increases in ocular tissue temperature that surpassed the safe limit (increases >1.5°C) in the lens of 3 rabbits (at 5.0, 5.5, and 1.5 minutes) and cornea of 2 rabbits (both at 1.5 minutes). A secondary analysis of temporal temperature differences between the orbital-rated and nonorbital transducers revealed statistically significant differences (Bonferroni-adjusted P < 0.05) in the cornea at 3.5 minutes, the lens at 2.5 minutes, and the vitreous at 4.0 minutes. Light microscopy and histology failed to elicit ocular injury in either group. CONCLUSIONS The nonorbital-rated ultrasound machine (Sonosite Micromaxx) increases the ocular tissue temperature. A larger study is needed to establish safety. Until then, ophthalmic ultrasound-guided blocks should only be performed with ocular-rated devices.
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Affiliation(s)
- Howard D Palte
- Department of Anesthesiology, Perioperative Medicine and Pain Management, Miller School of Medicine, 900 NW 17th Street, Miami FL 33136, USA.
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20
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Abstract
During blink down-phase, the levator palpebrae superioris (levator) muscle is inactivated, allowing the orbicularis oculi muscle to act. For trigeminal reflex blinks, the excitatory connections from trigeminal sensory nuclei to the facial nucleus have been described, but the pathway whereby the levator is turned off have not. We examined this question by use of both physiological and anatomical approaches in the cat. Intracellular records from antidromically activated levator motoneurons revealed that periorbital electrical stimulation produced bilateral, long latency inhibitory postsynaptic potentials (IPSPs). Central electrical stimulation of the principal trigeminal nucleus produced shorter latency IPSPs. Intracellular staining revealed that these motoneurons reside in the caudal central subdivision and have 10 or more poorly branched dendrites, which extend bilaterally into the surrounding supraoculomotor area. Axons penetrated in this region could be activated from periorbital and central electrodes. Neurons labeled from tracer injections into the caudal oculomotor complex were distributed in a crescent-shaped band that lined the ventral and rostral aspects of the pontine trigeminal sensory nucleus. Double-label immunohistochemical procedures demonstrated that these cells were not tyrosine hydroxylase-positive cells in the Kölliker-Fuse area. Instead, supraorbital nerve afferents displayed a similar crescent-shaped distribution, suggesting they drive these trigemino-oculomotor neurons. Anterograde labeling of the trigemino-oculomotor projection indicates that it terminates bilaterally, in and above the caudal central subdivision. These results characterize a trigemino-oculomotor pathway that inhibits levator palpebrae motoneurons in response to blink-producing periorbital stimuli. The bilateral distributions of trigemino-oculomotor afferents, levator motoneurons, and their dendrites supply a morphological basis for conjugate lid movements.
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Affiliation(s)
- Paul J May
- Department of Neurobiology and Anatomical Sciences, Departments of Ophthalmology and Neurology, University of Mississippi Medical Center, Jackson, Mississippi 39216, USA.
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21
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Zhukov VV, Tuchina OP, Meĭer-Rokhov VB. [Serotonin immunoreactivity in the optic nerve and in the eye of pulmonate gastropods]. Zh Evol Biokhim Fiziol 2012; 48:402-404. [PMID: 23013030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
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22
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Basova NE, Kormilitsyn BN, Perchenok AI, Rozengart EV, Saakov VS, Suvorov AA. [Reversible lupininin inhibitors of cholinesterases of mammalian blood and of optical ganglia of individuals of the commander squid Berryteuthis magister from different zones of species areal]. Zh Evol Biokhim Fiziol 2012; 48:213-218. [PMID: 22827020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Arylsulfoesters and carbonic lupinin esters are studied for the first time as reversible inhibitors of mammalian blood cholinesterases. Studied in detail is sensitivity of cholinesterases to mono- and bislupinin inhibitors in Commander squid individuals from different habitation zones.
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Körtvélyes J, Bankó EM, Andics A, Rudas G, Németh J, Hermann P, Vidnyánszky Z. Visual cortical responses to the input from the amblyopic eye are suppressed during binocular viewing. Acta Biol Hung 2012; 63 Suppl 1:65-79. [PMID: 22453742 DOI: 10.1556/abiol.63.2012.suppl.1.7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Amblyopia is a visual disorder caused by an anomalous early visual experience. It has been suggested that suppression of the visual input from the weaker eye might be a primary underlying mechanism of the amblyopic syndrome. However, it is still an unresolved question to what extent neural responses to the visual information coming from the amblyopic eye are suppressed during binocular viewing. To address this question we measured event-related potentials (ERP) to foveal face stimuli in amblyopic patients, both in monocular and binocular viewing conditions. The results revealed no difference in the amplitude and latency of early components of the ERP responses between the binocular and fellow eye stimulation. On the other hand, early ERP components were reduced and delayed in the case of monocular stimulation of the amblyopic eye as compared to the fellow eye stimulation or to binocular viewing. The magnitude of the amblyopic effect measured on the ERP amplitudes was comparable to that found on the fMRI responses in the fusiform face area using the same face stimuli and task conditions. Our findings showing that the amblyopic effects present on the early ERP components in the case of monocular stimulation are not manifested in the ERP responses during binocular viewing suggest that input from the amblyopic eye is completely suppressed already at the earliest stages of visual cortical processing when stimuli are viewed by both eyes.
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Affiliation(s)
- Judit Körtvélyes
- Faculty of Information Technology, Pázmány Péter Catholic University, Budapest, Hungary
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Lehmann T, Hess M, Melzer RR. Wiring a periscope--ocelli, retinula axons, visual neuropils and the ancestrality of sea spiders. PLoS One 2012; 7:e30474. [PMID: 22279594 PMCID: PMC3261207 DOI: 10.1371/journal.pone.0030474] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2011] [Accepted: 12/19/2011] [Indexed: 11/19/2022] Open
Abstract
The Pycnogonida or sea spiders are cryptic, eight-legged arthropods with four median ocelli in a 'periscope' or eye tubercle. In older attempts at reconstructing phylogeny they were Arthropoda incertae sedis, but recent molecular trees placed them as the sister group either to all other euchelicerates or even to all euarthropods. Thus, pycnogonids are among the oldest extant arthropods and hold a key position for the understanding of arthropod evolution. This has stimulated studies of new sets of characters conductive to cladistic analyses, e.g. of the chelifores and of the hox gene expression pattern. In contrast knowledge of the architecture of the visual system is cursory. A few studies have analysed the ocelli and the uncommon "pseudoinverted" retinula cells. Moreover, analyses of visual neuropils are still at the stage of Hanström's early comprehensive works. We have therefore used various techniques to analyse the visual fibre pathways and the structure of their interrelated neuropils in several species. We found that pycnogonid ocelli are innervated to first and second visual neuropils in close vicinity to an unpaired midline neuropil, i.e. possibly the arcuate body, in a way very similar to ancestral euarthropods like Euperipatoides rowelli (Onychophora) and Limulus polyphemus (Xiphosura). This supports the ancestrality of pycnogonids and sheds light on what eyes in the pycnogonid ground plan might have 'looked' like. Recently it was suggested that arthropod eyes originated from simple ocelli similar to larval eyes. Hence, pycnogonid eyes would be one of the early offshoots among the wealth of more sophisticated arthropod eyes.
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Abstract
Muscarinic agonists act mainly via muscarinic M₃ cholinoceptors to cause contraction of the iris sphincter, ciliary muscle and trabecular meshwork as well as increase outflow facility of aqueous humour. In the iris dilator, the effect of muscarinic agonists is species dependent but is predominantly relaxation via muscarinic M₃ receptors. In the conjunctiva, muscarinic agonists stimulate goblet cell secretion which contributes to the protective tear film. Muscarinic M₂ and M₃ receptors appear mainly involved. In the lens muscarinic agonists act via muscarinic M₁ receptors to produce depolarization and increase [Ca(2+)](i). All five subtypes of muscarinic receptor are present in the retina. In the developing retina, acetylcholine appears to limit purinergic stimulation of retinal development and decrease cell proliferation. In the adult retina acetylcholine and other muscarinic agonists may have complex effects, for example, enhancing light-evoked neuronal firing in transient ON retinal ganglion cells and inhibiting firing in OFF retinal ganglion cells. In the lacrimal gland, muscarinic agonists activate M₃ receptors on secretory globular acinar cells to stimulate tear secretion and also cause contraction of myoepithelial cells. In Sjögren's syndrome, antibodies to the muscarinic M₃ receptor disrupt normal gland function leading to xerophthalmia although the mechanism of action of the antibody is still not clear. Atropine and pirenzepine are useful in limiting the development of myopia in children probably by an action on muscarinic receptors in the sclera, although many other muscarinic receptor antagonists are not effective.
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Affiliation(s)
- Frederick Mitchelson
- Department of Pharmacology, University of Melbourne, Melbourne, VIC 3010, Australia.
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Rykov SA, Torchinskaia NV, Bakbardina II, Simchuk IV. [Ligation of the retrobulbar vascular-nervous bunch during performance of evisceration and enucleation using titanic clips in ophthalmic surgery]. Klin Khir 2011:43-45. [PMID: 22295551] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The efficacy of hemostasis achievement during conduction of a retrobulbar vascular-nervous bunch ligation (RVNBL), using titanic clips while evisceroenucleation performance, was studied up. A comparative analysis of clinical and functional results of surgical treatment of 36 patients, suffering terminal dolorous glaucoma and disaster of a sympathetic ophthalmia complication after an eye penetrating wounding occurrence. In 16 patients (the first group) a standard method of a hemostasis achievement was used while doing evisceroenucleation - a deep orbital tamponade for 5 minutes. In 20 patients (the second group) a procedure of RVNBL was conducted, using titanic clips before the bunch transsection doing. There was established, that while doing a RVNPL using titanic clips, a hemorrhage never occurs, a retrobulbar hematoma do not formated, the soft tissues reaction in the early postoperative period is less pronounced, and the patients postoperative rehabilitation period shortens.
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Pan S, Li L, Xu Z, Zhao J. Effect of leukemia inhibitory factor on corneal nerve regeneration of rabbit eyes after laser in situ keratomileusis. Neurosci Lett 2011; 499:99-103. [PMID: 21640792 DOI: 10.1016/j.neulet.2011.05.042] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2011] [Revised: 05/08/2011] [Accepted: 05/16/2011] [Indexed: 11/19/2022]
Abstract
To explore the effect of leukemia inhibitory factor on corneal nerve regeneration in a rabbit model after laser in situ keratomileusis. Thirty five healthy New Zealand rabbits were divided into three groups for a 6-month observation, the blank control group, the control group, and the treatment group respectively. Laser in situ keratomileusis for myopia was performed on 30 rabbits (60 eyes in total) and then 1 μg/ml LIF eye drops were used four times a day on the left eyes as the treatment group, and the balanced salt solution (BSS) was used on the right eyes as the control group. Nerve regeneration was evaluated by counting the new regenerated nerves in golden chloride staining. The parameters for dry eye include Schirmer I test and tear break-up time were also examined. The number of regenerated nerve fibers in the treatment group was significantly higher than that in the control group at all time points except the 6th month after LASIK (P<0.05). The parameters for dry eye between two groups were compared at each postoperative time point and the results showed they were significantly higher in the LIF-treated group than in the BSS-control group at 2w, 1m, and 3m respectively. Leukemia inhibitory factor can effectively accelerate the corneal nerve regeneration of rabbit eyes after LASIK surgery and decrease the occurrence of dry eye symptoms.
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Affiliation(s)
- Shuling Pan
- Ophthalmology Center, the Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, China
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Orihara-Ono M, Toriya M, Nakao K, Okano H. Downregulation of Notch mediates the seamless transition of individual Drosophila neuroepithelial progenitors into optic medullar neuroblasts during prolonged G1. Dev Biol 2011; 351:163-75. [PMID: 21215740 DOI: 10.1016/j.ydbio.2010.12.044] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2010] [Revised: 12/29/2010] [Accepted: 12/30/2010] [Indexed: 11/17/2022]
Abstract
The first step in the development of the Drosophila optic medullar primordia is the expansion of symmetrically dividing neuroepithelial cells (NEs); this step is then followed by the appearance of asymmetrically dividing neuroblasts (NBs). However, the mechanisms responsible for the change from NEs to NBs remain unclear. Here, we performed detailed analyses demonstrating that individual NEs are converted into NBs. We also showed that this transition occurs during an elongated G1 phase. During this G1 phase, the morphological features and gene expressions of each columnar NE changed dynamically. Once the NE-to-NB transition was completed, the former NE changed its cell-cycling behavior, commencing asymmetric division. We also found that Notch signaling pathway was activated just before the transition and was rapidly downregulated. Furthermore, the clonal loss of the Notch wild copy in the NE region near the medial edge caused the ectopic accumulation of Delta, leading to the precocious onset of transition. Taken together, these findings indicate that the activation of Notch signaling during a finite window coordinates the proper timing of the NE-to-NB transition.
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Affiliation(s)
- Minako Orihara-Ono
- Department of Physiology, Faculty of Medicine, Keio University, Tokyo, Zip 160-8582, Japan
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29
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Stefanescu AM, Gradinaru SL, Tugui A, Ciuluvica R. [Headache--from an ophthalmic point of view]. Oftalmologia 2011; 55:30-37. [PMID: 22428290] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The authors approach a subject keen to neuroophthalmologists, which is becoming more and more frequent with the overuse of VTU (videoterminal unit). They hope to better understand the headache (from an ophthalmic point of view), and how to diagnose it better and faster.
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30
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Gavrilenko AV, Kuklin AV, Kiseleva TN, Omarzhanova II. [Long-term follow-up results of carotid endarterectomy in patients with carotid stenosis and transient monocular blindness]. Khirurgiia (Mosk) 2011:48-50. [PMID: 21716219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The study aimed to prove the efficacy of carotid endarterectomy in patients with transient monocular blindness caused by carotid arterial stenosis. 31 patients, aged 45-80 years, were included in the study. All patients were divided in 2 groups: 16 patients from the first group had classic carotid endarterectomy with synthetic patch; 15 patients from the second group were treated conservatively. All operated patients had no stroke or transient ischemic attack and were spared from amaurosis attacks and even showed certain vision sharpness improvement. Whereas the majority of patients from the second group showed the recurrence of the amaurosis fugax attacks after the treatment. Carotid endarterectomy significantly improves the condition of an eye and prevents brain ischemia in patients with transient monocular blindness caused by carotid arterial stenosis.
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Todd PK, Oh SY, Krans A, Pandey UB, Di Prospero NA, Min KT, Taylor JP, Paulson HL. Histone deacetylases suppress CGG repeat-induced neurodegeneration via transcriptional silencing in models of fragile X tremor ataxia syndrome. PLoS Genet 2010; 6:e1001240. [PMID: 21170301 PMCID: PMC3000359 DOI: 10.1371/journal.pgen.1001240] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2010] [Accepted: 11/04/2010] [Indexed: 01/15/2023] Open
Abstract
Fragile X Tremor Ataxia Syndrome (FXTAS) is a common inherited neurodegenerative disorder caused by expansion of a CGG trinucleotide repeat in the 5'UTR of the fragile X syndrome (FXS) gene, FMR1. The expanded CGG repeat is thought to induce toxicity as RNA, and in FXTAS patients mRNA levels for FMR1 are markedly increased. Despite the critical role of FMR1 mRNA in disease pathogenesis, the basis for the increase in FMR1 mRNA expression is unknown. Here we show that overexpressing any of three histone deacetylases (HDACs 3, 6, or 11) suppresses CGG repeat-induced neurodegeneration in a Drosophila model of FXTAS. This suppression results from selective transcriptional repression of the CGG repeat-containing transgene. These findings led us to evaluate the acetylation state of histones at the human FMR1 locus. In patient-derived lymphoblasts and fibroblasts, we determined by chromatin immunoprecipitation that there is increased acetylation of histones at the FMR1 locus in pre-mutation carriers compared to control or FXS derived cell lines. These epigenetic changes correlate with elevated FMR1 mRNA expression in pre-mutation cell lines. Consistent with this finding, histone acetyltransferase (HAT) inhibitors repress FMR1 mRNA expression to control levels in pre-mutation carrier cell lines and extend lifespan in CGG repeat-expressing Drosophila. These findings support a disease model whereby the CGG repeat expansion in FXTAS promotes chromatin remodeling in cis, which in turn increases expression of the toxic FMR1 mRNA. Moreover, these results provide proof of principle that HAT inhibitors or HDAC activators might be used to selectively repress transcription at the FMR1 locus.
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Affiliation(s)
- Peter K Todd
- Department of Neurology, University of Michigan, Ann Arbor, Michigan, United States of America.
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Schwartzman DJ, Kranczioch C. In the blink of an eye: the contribution of microsaccadic activity to the induced γ band response. Int J Psychophysiol 2010; 79:73-82. [PMID: 20971138 DOI: 10.1016/j.ijpsycho.2010.10.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2010] [Revised: 10/14/2010] [Accepted: 10/16/2010] [Indexed: 11/17/2022]
Abstract
In 2008 an article by Yuval-Greenberg and colleagues initiated a lively debate within the field of induced gamma band research. Their article suggested that scalp-recorded induced gamma band responses (iGBRs) to visual stimuli could be obscured by minute movements of extraocular muscles, called microsaccades, which are associated with the saccadic spike potentials (SPs). Yuval-Greenberg et al. (2008) proposed that the temporal and spectral characteristics of SPs could mask and have been previously mistaken for cortical induced gamma band activity. This review summarises the main findings of the report by Yuval-Greenberg et al. (2008) and the research that has emerged since its publication. Microsaccades and the associated SP waveforms are described in detail and their contribution to the iGBR discussed. Different lines of argument are considered that suggest that the scalp-recorded iGBR exists separate from ocular contributions. The article then considers techniques that are widely used to remove electroencephalogram (EEG) artefacts and their potential adaptation for the removal of SPs. The review closes by pointing to future directions that researchers may explore in order to disentangle neural iGBRs and artefactual, SP-related iGBRs, and to several routes which researchers may consider in order to increase the informative value of their scalp-recorded iGBR data. We conclude that further investigation and testing is necessary to develop signal processing tools that successfully identify and correct SPs in EEG data without distorting the neural iGBR.
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Affiliation(s)
- David J Schwartzman
- Department of Psychology, Oxford Brookes University, Gipsy Lane, Headington, Oxford, OX3 0BP, UK.
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Plotnikova SI. [Comissure between optic centers of eyes in locust Locusta migratoria]. Zh Evol Biokhim Fiziol 2010; 46:442-444. [PMID: 21061657] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
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Iagodina OV. [Comparative study of substrate and inhibitory specificity of monoamine oxidase in the optic ganglia of squids]. Zh Evol Biokhim Fiziol 2010; 46:191-197. [PMID: 20583578] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Comparative study of substrate specificity of monoamine oxidase (MAO) of optic ganglia of the Pacific squid Todarodes pacificus and the Commander squid Berryteuthis magister has been carried out. The enzyme of the Pacific squid, unlike that of the Commander squid, has been established to be able to deaminate not only tyramine, tryptamine, serotonin, benzylamine, and beta-phenylethylamine, but also histamine--substrate of diamine oxidase (DAO). In relation to all studied substrates, the MAO activity of optic ganglia of T. pacificus is several times higher as compared with B. magister. In the case of deamination of serotonin this difference was the greatest and amounted to 5 times. Semicarbazide, the classic DAO inhibitor, at a concentration of 10 mM did not inhibit catalytic activity of both studied enzymes. The substrate-inhibitory analysis with use of deprenyl and chlorogiline, specific inhibitors of different MAO forms, indicates homogeneity of the enzyme of the Pacific squid and heterogeneity of the Commander squid enzyme whose composition seems probably to contain at least two MAO forms. There are obtained quantitative differences in substrate specificity and reaction capability with respect to the inhibitors chlorgiline and deprenyl for MAO of optic ganglia of the studied squid species. These differences probably can be explained by significant differences in the evolutionary level of these biological species.
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Barth M, Schultze M, Schuster CM, Strauss R. Circadian plasticity in photoreceptor cells controls visual coding efficiency in Drosophila melanogaster. PLoS One 2010; 5:e9217. [PMID: 20169158 PMCID: PMC2821403 DOI: 10.1371/journal.pone.0009217] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2009] [Accepted: 01/20/2010] [Indexed: 12/05/2022] Open
Abstract
In the fly Drosophila melanogaster, neuronal plasticity of synaptic terminals in the first optic neuropil, or lamina, depends on early visual experience within a critical period after eclosion [1]. The current study revealed two additional and parallel mechanisms involved in this type of synaptic terminal plasticity. First, an endogenous circadian rhythm causes daily oscillations in the volume of photoreceptor cell terminals. Second, daily visual experience precisely modulates the circadian time course and amplitude of the volume oscillations that the photoreceptor-cell terminals undergo. Both mechanisms are separable in their molecular basis. We suggest that the described neuronal plasticity in Drosophila ensures continuous optimal performance of the visual system over the course of a 24 h-day. Moreover, the sensory system of Drosophila cannot only account for predictable, but also for acute, environmental changes. The volumetric changes in the synaptic terminals of photoreceptor cells are accompanied by circadian and light-induced changes of presynaptic ribbons as well as extensions of epithelial glial cells into the photoreceptor terminals, suggesting that the architecture of the lamina is altered by both visual exposure and the circadian clock. Clock-mutant analysis and the rescue of PER protein rhythmicity exclusively in all R1-6 cells revealed that photoreceptor-cell plasticity is autonomous and sufficient to control visual behavior. The strength of a visually guided behavior, the optomotor turning response, co-varies with synaptic-terminal volume oscillations of photoreceptor cells when elicited at low light levels. Our results show that behaviorally relevant adaptive processing of visual information is performed, in part, at the level of visual input level.
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Affiliation(s)
- Martin Barth
- Friedrich-Miescher-Laboratory of the Max-Planck Society (MPG), Tuebingen, Germany
| | - Michael Schultze
- Friedrich-Miescher-Laboratory of the Max-Planck Society (MPG), Tuebingen, Germany
| | | | - Roland Strauss
- Friedrich-Miescher-Laboratory of the Max-Planck Society (MPG), Tuebingen, Germany
- * E-mail:
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Thorburn W. Recordings of applanating force at constant intraocular pressure. IV. Intraocular volume changes due to changes in blood content. Acta Ophthalmol 2009; 51:270-85. [PMID: 4801584 DOI: 10.1111/j.1755-3768.1973.tb03803.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Tan L, Schedl P, Song HJ, Garza D, Konsolaki M. The Toll-->NFkappaB signaling pathway mediates the neuropathological effects of the human Alzheimer's Abeta42 polypeptide in Drosophila. PLoS One 2008; 3:e3966. [PMID: 19088848 PMCID: PMC2597734 DOI: 10.1371/journal.pone.0003966] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2008] [Accepted: 11/08/2008] [Indexed: 11/19/2022] Open
Abstract
Alzheimer's (AD) is a progressive neurodegenerative disease that afflicts a significant fraction of older individuals. Although a proteolytic product of the Amyloid precursor protein, the Alphabeta42 polypeptide, has been directly implicated in the disease, the genes and biological pathways that are deployed during the process of Alphabeta42 induced neurodegeneration are not well understood and remain controversial. To identify genes and pathways that mediated Alphabeta42 induced neurodegeneration we took advantage of a Drosophila model for AD disease in which ectopically expressed human Alphabeta42 polypeptide induces cell death and tissue degeneration in the compound eye. One of the genes identified in our genetic screen is Toll (Tl). It encodes the receptor for the highly conserved Tl-->NFkB innate immunity/inflammatory pathway and is a fly homolog of the mammalian Interleukin-1 (Ilk-1) receptor. We found that Tl loss-of-function mutations dominantly suppress the neuropathological effects of the Alphabeta42 polypeptide while gain-of-function mutations that increase receptor activity dominantly enhance them. Furthermore, we present evidence demonstrating that Tl and key downstream components of the innate immunity/inflammatory pathway play a central role in mediating the neuropathological activities of Alphabeta42. We show that the deleterious effects of Alphabeta42 can be suppressed by genetic manipulations of the Tl-->NFkB pathway that downregulate signal transduction. Conversely, manipulations that upregulate signal transduction exacerbate the deleterious effects of Abeta42. Since postmortem studies have shown that the Ilk-1-->NFkB innate immunity pathway is substantially upregulated in the brains of AD patients, the demonstration that the Tl-->NFkB signaling actively promotes the process of Alphabeta42 induced cell death and tissue degeneration in flies points to possible therapeutic targets and strategies.
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Affiliation(s)
- Lihua Tan
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, United States of America
| | - Paul Schedl
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, United States of America
| | - Ho-Juhn Song
- Novartis Institutes for Biomedical Research, Cambridge, Massachusetts, United States of America
| | - Dan Garza
- Novartis Institutes for Biomedical Research, Cambridge, Massachusetts, United States of America
| | - Mary Konsolaki
- Department of Genetics, Rutgers, The State University of New Jersey, Piscataway, New Jersey, United States of America
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Tolochko ZS, Spiridonov VK. [Disturbed microvascular permeability in the eye caused by capsaicin microinjections into the trigeminal caudalis nucleus]. Eksp Klin Farmakol 2008; 71:56-59. [PMID: 18488911] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Capsaicin microinjection into the trigeminal caudalis nucleus (the central projection area of trigeminal capsaicin-sensitive nerve) increase extravasation of proteins in rat eye. The effect was inhibited by ruthenium red introduction (a capsaicin receptor antagonist) and by blocking the effector functions of capsaicin-sensitive nerve endings. It is suggested that capsaicin stimulation of central terminations of trigeminal capsaicin-sensitive afferents induce an increase in the microvascular permeability of the eye, which is mediated through the effector function of capsaicin-sensitive nerves.
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Mrsic-Flogel TD, Hofer SB, Ohki K, Reid RC, Bonhoeffer T, Hübener M. Homeostatic regulation of eye-specific responses in visual cortex during ocular dominance plasticity. Neuron 2007; 54:961-72. [PMID: 17582335 DOI: 10.1016/j.neuron.2007.05.028] [Citation(s) in RCA: 247] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2006] [Revised: 03/27/2007] [Accepted: 05/31/2007] [Indexed: 11/15/2022]
Abstract
Experience-dependent plasticity is crucial for the precise formation of neuronal connections during development. It is generally thought to depend on Hebbian forms of synaptic plasticity. In addition, neurons possess other, homeostatic means of compensating for changes in sensory input, but their role in cortical plasticity is unclear. We used two-photon calcium imaging to investigate whether homeostatic response regulation contributes to changes of eye-specific responsiveness after monocular deprivation (MD) in mouse visual cortex. Short MD durations decreased deprived-eye responses in neurons with binocular input. Longer MD periods strengthened open-eye responses, and surprisingly, also increased deprived-eye responses in neurons devoid of open-eye input. These bidirectional response adjustments effectively preserved the net visual drive for each neuron. Our finding that deprived-eye responses were either weaker or stronger after MD, depending on the amount of open-eye input a cell received, argues for both Hebbian and homeostatic mechanisms regulating neuronal responsiveness during experience-dependent plasticity.
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Affiliation(s)
- Thomas D Mrsic-Flogel
- Department of Cellular and Systems Neurobiology, Max Planck Institute of Neurobiology, D-82152 Martinsried, Germany.
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Dabisch PA, Horsmon MS, Muse WT, Mioduszewski RJ, Thomson S. Muscarinic Receptor Dysfunction Induced by Exposure to Low Levels of Soman Vapor. Toxicol Sci 2007; 100:281-9. [PMID: 17693423 DOI: 10.1093/toxsci/kfm213] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
In the eye, it has been previously reported that exposure to a cholinesterase inhibitor results in a reduced miotic response following prolonged exposure and a decreased miotic response to the cholinergic agonists. However, no studies exist that characterize the effect of a single low-level vapor exposure to a nerve agent on parasympathetic function in the eye or determine the threshold dose for such an effect. The present study investigated the hypotheses that a single low-level exposure to soman vapor would result in dysfunction of the parasympathetic pathway mediating the pupillary light reflex resulting from a loss of muscarinic receptor function on the pupillary sphincter muscle. Adult male rats were exposed to soman vapor in a whole-body dynamic airflow exposure chamber. Rats exposed to low levels of soman vapor dose-dependently developed miosis (threshold dose between 4.1 and 6.1 mg-min/m3). Pupil size returned to preexposure levels within 48 h due to desensitization of pupillary muscarinic receptors, as assessed by the pupillary response to the muscarinic agonist oxotremorine. An attenuated pupillary light reflex was also present in miotic animals (threshold dose near 6.1 mg-min/m3). While pupil size recovers within 48 h, other measures of pupillary function, including the light reflex, acetylcholinesterase activity, and muscarinic receptor responsiveness, did not return to normal for up to 10 days postexposure. Recovery of the light reflex coincided with the recovery of pupillary muscarinic receptor function, suggesting that the attenuation of the light reflex was due to receptor desensitization.
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Affiliation(s)
- Paul A Dabisch
- Operational Toxicology Team, U.S. Army Edgewood Chemical Biological Center, Aberdeen Proving Ground, Maryland 21010-5424, USA.
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Dabisch PA, To F, Kerut EK, Horsmon MS, Mioduszewski RJ. Multiple exposures to sarin vapor result in parasympathetic dysfunction in the eye but not the heart. Toxicol Sci 2007; 99:354-61. [PMID: 17578861 DOI: 10.1093/toxsci/kfm167] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Several studies in conscious animals have reported parasympathetic dysfunction in the eyes following exposure to cholinesterase inhibitors. Given the similarities between the autonomic innervation in the eye and the heart, it is possible that parasympathetic dysfunction could also occur in the heart. Therefore, the present study assessed time domain indices of heart rate variability in conscious rats surgically implanted with telemetric transmitters to investigate the hypothesis that multiple exposures to the nerve agent sarin would result in muscarinic receptor desensitization and parasympathetic dysfunction in the heart. Animals exposed to sarin vapor on multiple occasions developed parasympathetic dysfunction in the eye characterized by an attenuated response to light and a diminished miotic response to sarin vapor exposure. However, the same dose of sarin vapor failed to produce any effects on either time domain indices of HRV or the magnitude of the tachycardia induced by atropine, suggesting that autonomic control in the heart was not affected. It is possible that the dose of sarin used in the present study was insufficient to inhibit cardiac acetylcholinesterase (AChE). Additional studies utilizing higher doses of sarin may be able to inhibit cardiac AChE, producing overstimulation of cardiac muscarinic receptors, ultimately resulting in desensitization and parasympathetic dysfunction.
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Affiliation(s)
- Paul A Dabisch
- Operational Toxicology Team, U.S. Army Edgewood Chemical Biological Center, Aberdeen Proving Ground, Maryland 21010, USA.
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Abstract
It has recently been reported that a strong correlation exists between the distribution of retinal ganglion cells and nose length in the domestic dog. To determine if this phenomenon occurs in another domestic species with diverse skull morphology, the current study examined the distribution of retinal ganglion cells in 30 horses from a variety of breeds. There was a significant variation in the density of ganglion cells found across the retinae. Breed was a significant predictor for ganglion cell density within the visual streak. A strong positive correlation exists between the density of ganglion cells in the visual streak and nasal length. Significant variation was also seen in the area centralis but did not correlate with any of the recorded skull measurements. The findings of this study provide us with further understanding of the equine visual system and the level of variation that exists between individuals of the same species.
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Affiliation(s)
- K E Evans
- Faculty of Veterinary Science, Gunn Building (B19), Regimental Crescent, University of Sydney, Sydney, NSW 2006, Australia
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Bazigou E, Apitz H, Johansson J, Lorén CE, Hirst EMA, Chen PL, Palmer RH, Salecker I. Anterograde Jelly belly and Alk receptor tyrosine kinase signaling mediates retinal axon targeting in Drosophila. Cell 2007; 128:961-75. [PMID: 17350579 DOI: 10.1016/j.cell.2007.02.024] [Citation(s) in RCA: 103] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2006] [Revised: 10/20/2006] [Accepted: 02/16/2007] [Indexed: 10/23/2022]
Abstract
Anaplastic lymphoma kinase (Alk) has been proposed to regulate neuronal development based on its expression pattern in vertebrates and invertebrates; however, its function in vivo is unknown. We demonstrate that Alk and its ligand Jelly belly (Jeb) play a central role as an anterograde signaling pathway mediating neuronal circuit assembly in the Drosophila visual system. Alk is expressed and required in target neurons in the optic lobe, whereas Jeb is primarily generated by photoreceptor axons and functions in the eye to control target selection of R1-R6 axons in the lamina and R8 axons in the medulla. Impaired Jeb/Alk function affects layer-specific expression of three cell-adhesion molecules, Dumbfounded/Kirre, Roughest/IrreC, and Flamingo, in the medulla. Moreover, loss of flamingo in target neurons causes some R8-axon targeting errors observed in Jeb and Alk mosaic animals. Together, these findings suggest that Jeb/Alk signaling helps R-cell axons to shape their environment for target recognition.
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Affiliation(s)
- Eleni Bazigou
- Division of Molecular Neurobiology, MRC National Institute for Medical Research, London NW7 1AA, UK
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Abstract
The immune-privileged status of the anterior chamber of the eye is altered in experimentally induced intraocular inflammation and in the pigment dispersion syndrome of DBA/2J mice. However, the eye has developed multiple mechanisms to maintain ocular immune privilege even in the presence of intraocular inflammation.
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Affiliation(s)
- Jun-Song Mo
- Departments of Ophthalmology and Visual Sciences, University of Louisville School of Medicine, Louisville, Ky., USA
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Krijnen JSM, Jansen SM, van Rijn LJ. [An asymmetrical face due to torticollis in two young children]. Ned Tijdschr Geneeskd 2007; 151:669-70; author reply 670. [PMID: 17443949] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
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Abstract
The Myc oncoprotein is a potent inducer of cell growth, cell cycle progression, and apoptosis. While many direct Myc target genes have been identified, the molecular determinants of Myc's transcriptional specificity remain elusive. We have carried out a genetic screen in Drosophila and identified the Trithorax group protein Little imaginal discs (Lid) as a regulator of dMyc-induced cell growth. Lid binds to dMyc and is required for dMyc-induced expression of the growth regulatory gene Nop60B. The mammalian Lid orthologs, Rbp-2 (JARID1A) and Plu-1 (JARID1B), also bind to c-Myc, indicating that Lid-Myc function is conserved. We demonstrate that Lid is a JmjC-dependent trimethyl H3K4 demethylase in vivo and that this enzymatic activity is negatively regulated by dMyc, which binds to Lid's JmjC domain. Because Myc binding is associated with high levels of trimethylated H3K4, we propose that the Lid-dMyc complex facilitates Myc binding to, or maintenance of, this chromatin context.
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Affiliation(s)
- Julie Secombe
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington 98109, USA
| | - Ling Li
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington 98109, USA
| | - Leni Carlos
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington 98109, USA
| | - Robert N. Eisenman
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington 98109, USA
- Corresponding author.E-MAIL ; FAX (206) 667-6522
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Campana G, Cowey A, Casco C, Oudsen I, Walsh V. Left frontal eye field remembers “where” but not “what”. Neuropsychologia 2007; 45:2340-5. [PMID: 17449069 DOI: 10.1016/j.neuropsychologia.2007.02.009] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2006] [Revised: 12/11/2006] [Accepted: 02/11/2007] [Indexed: 10/23/2022]
Abstract
Short-term memory of basic stimulus features seems to rely upon low-level functional components of the visual pathways. By using a repetition priming paradigm, we previously showed that visual area V5/MT is important for holding motion direction information, but not spatial position information. Here we extend our previous findings and investigate the possible locus of spatial position priming. We compare the effect of repetitive transcranial magnetic stimulation (rTMS) over right angular gyrus and left and right frontal eye fields on priming for spatial position and motion direction. TMS over left frontal eye field selectively and significantly reduced priming for spatial position but there was no significant effect of TMS over right parietal or right frontal eye field. These results suggest that FEF neurons are implicated in short-term memory storage of spatial position, and extend and support the idea that memory for basic stimulus features is retained within the sensory areas that respond to primary stimulus attributes. They add to a growing body of evidence that the frontal eye fields are involved in many visual functions independent of eye movements.
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Affiliation(s)
- Gianluca Campana
- Dipartimento di Psicologia Generale, Università di Padova, Via Venezia 8, 35131 Padova, Italy.
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Brascamp JW, van Ee R, Noest AJ, Jacobs RHAH, van den Berg AV. The time course of binocular rivalry reveals a fundamental role of noise. J Vis 2006; 6:1244-56. [PMID: 17209732 DOI: 10.1167/6.11.8] [Citation(s) in RCA: 136] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2006] [Accepted: 09/18/2006] [Indexed: 11/24/2022] Open
Abstract
When our two eyes view incongruent images, we experience binocular rivalry: An ongoing cycle of dominance periods of either image and transition periods when both are visible. Two key forces underlying this process are adaptation of and inhibition between the images' neural representations. Models based on these factors meet the constraints posed by data on dominance periods, but these are not very stringent. We extensively studied contrast dependence of dominance and transition durations and that of the occurrence of return transitions: Occasions when an eye loses and regains dominance without intervening dominance of the other eye. We found that dominance durations and the incidence of return transitions depend similarly on contrast; transition durations show a different dependence. Regarding dominance durations, we show that the widely accepted rule known as Levelt's second proposition is only valid in a limited contrast range; outside this range, the opposite of the proposition is true. Our data refute current models, based solely on adaptation and inhibition, as these cannot explain the long and reversible transitions that we find. These features indicate that noise is a crucial force in rivalry, frequently dominating the deterministic forces.
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Affiliation(s)
- Jan W Brascamp
- Functional Neurobiology and Helmholtz Institute, Utrecht University, Utrecht, The Netherlands.
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