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The Journal of Neuroscience : the... Aug 1981The optic nerves, tracts, and tecta of goldfish, 1 to 5 years old, have been studied anatomically using light and electron microscopy, horseradish peroxidase (HRP), and...
The optic nerves, tracts, and tecta of goldfish, 1 to 5 years old, have been studied anatomically using light and electron microscopy, horseradish peroxidase (HRP), and tritiated proline radioautography. The aims were to document an earlier inference that fibers are added to the nerve continually and to describe the growth and organization of the pathway. (1) The numbers of optic fibers were counted in electron micrographs of the nerve. There were about 120,000, 165,000 and 180,000 in 1-, 3-, and 5-year-old fish, respectively. (2) In young fish, there are a few thousand nonmyelinated fibers which exit the retina together and cluster together in the nerve and tract. When the axons of only the newest (peripheral) ganglion cells were cut intraretinally, fibers in and around the bundles of nonmyelinated fibers degenerated. The nonmyelinated fibers are, therefore, the new ones. (3) Fibers from ventral or dorsal hemiretinas were backfilled selectively with HRP introduced into one of the brachia of the optic tract. Behind the optic papilla, where the cross-section of the optic nerve was trapezoidal, the new fibers were found in a strip along the narrow base of the two flanking zones. Closer to the brain, the fibers from the two hemiretinas intermingled before being segregated again at the origin of the brachia. (4) Small groups of ganglion cells were labeled by intraretinal injection of HRP and their fibers were traced in sections of the nerve and tract. The labeled fibers were clustered, but the positions of the fibers in the cross-section of the nerve were defined less precisely than the positions of the somata in the retina. (5) Hemisection of the nerve in the orbit, followed by intraocular injection of tritiated proline, produced radioautographs with an unlabeled annular zone of tectum. Since the retina projects topographically to the tectum, the severed fibers must have originated from an annular region of the retina. We infer that new fibers are added to the nerve continually and that the retinal origins of fibers are correlated with their positions in the cross-section of the nerve. These rules of order change with distance from the retina; the strict order at the optic papilla changes gradually to an equally strict but different, order at the level of the brachia.
Topics: Animals; Autoradiography; Cyprinidae; Goldfish; Nerve Fibers; Nerve Fibers, Myelinated; Optic Nerve; Superior Colliculi
PubMed: 7346585
DOI: 10.1523/JNEUROSCI.01-08-00793.1981 -
Journal of Neuroinflammation Jul 2018Following injury to the central nervous system, increased microglia, secretion of pro- and anti-inflammatory cytokines, and altered blood-brain barrier permeability, a...
BACKGROUND
Following injury to the central nervous system, increased microglia, secretion of pro- and anti-inflammatory cytokines, and altered blood-brain barrier permeability, a hallmark of degeneration, are observed at and immediately adjacent to the injury site. However, few studies investigate how regions remote from the primary injury could also suffer from inflammation and secondary degeneration.
METHODS
Adult female Piebald-Viral-Glaxo (PVG) rats underwent partial transection of the right optic nerve, with normal, age-matched, unoperated animals as controls. Perfusion-fixed brains and right optic nerves were harvested for immunohistochemical assessment of inflammatory markers and blood-brain barrier integrity; fresh-frozen brains were used for multiplex cytokine analysis.
RESULTS
Immediately ventral to the optic nerve injury, immunointensity of both the pro-inflammatory biomarker inducible nitric oxide synthase (iNOS) and the anti-inflammatory biomarker arginase-1 (Arg1) increased at 7 days post-injury, with colocalization of iNOS and Arg1 immunoreactivity within individual cells. CD11b+ and CD45+ cells were increased 7 days post-injury, with altered BBB permeability still evident at this time. In the lower and middle optic tract and superior colliculus, IBA1+ resident microglia were first increased at 3 days; ED1+ and CD11b+ cells were first increased in the middle and upper tract and superior colliculus 7 days post-injury. Increased fibrinogen immunoreactivity indicative of altered BBB permeability was first observed in the contralateral upper tract at 3 days and middle tract at 7 days post-injury. Multiplex cytokine analysis of brain homogenates indicated significant increases in the pro-inflammatory cytokines, IL-2 and TNFα, and anti-inflammatory cytokine IL-10 1 day post-injury, decreasing to control levels at 3 days for TNFα and 7 days for IL-2. IL-10 was significantly elevated at 1 and 7 days post-injury with a dip at 3 days post-injury.
CONCLUSIONS
Partial injury to the optic nerve induces a complex remote inflammatory response, characterized by rapidly increased pro- and anti-inflammatory cytokines in brain homogenates, increased numbers of IBA1+ cells throughout the visual pathways, and increased CD11b+ and ED1+ inflammatory cells, particularly towards the synaptic terminals. BBB permeability can increase prior to inflammatory cell infiltration, dependent on the brain region.
Topics: Analysis of Variance; Animals; Antigens, CD; Blood-Brain Barrier; Calcium-Binding Proteins; Cytokines; Disease Models, Animal; Ectodysplasins; Encephalitis; Female; Fibrinogen; Functional Laterality; Macrophages; Microfilament Proteins; Microglia; Nitric Oxide Synthase Type II; Optic Nerve; Optic Nerve Injuries; Rats; Time Factors; Visual Pathways
PubMed: 29981582
DOI: 10.1186/s12974-018-1227-0 -
Advances in Ophthalmology Practice and... Dec 2021Magnetic resonance imaging (MRI) plays a significant role in assessing optic neuropathy and providing more detailed information about the lesion of the visual pathway to... (Review)
Review
BACKGROUND
Magnetic resonance imaging (MRI) plays a significant role in assessing optic neuropathy and providing more detailed information about the lesion of the visual pathway to help differentiate optic neuritis from other visual disorders. This study aims to systematically review the literature and verify if there is a real difference in lesion location among different demyelinating optic neuritis (DON) subtypes.
METHODS
A systematic search was conducted including 8 electronic databases and related resources from the establishment of the database to August 25th, 2020. We classified DON into 5 subtypes and divided the visual pathways into five segments mainly comparing the differences in the involved visual pathway sites of different subtypes.
RESULTS
Fifty-five studies were included in the analysis, and the abnormal rate was as high as 92% during the acute phase (within 4 weeks of symptom onset). With respect to lesion location, the orbital segment of the optic nerve was the most frequently involved (87%), whereas optic tract involvement was very rare. Involvement of the orbital segment was more common in myelin oligodendrocyte glycoprotein antibody-related optic neuritis (MOG-ON) (78%) and chronic relapsing inflammatory optic neuropathy (CRION) (81%), while the lesion was found to be located more posteriorly in neuromyelitis optica spectrum disorder-related optic neuritis (NMOSD-ON). With respect to lesion length, approximately 77% of MOG-ON patients had lesions involving more than half of the optic nerve length.
CONCLUSIONS
MRI examination is recommended for DON patients in the acute phase. In MOG-ON, anterior involvement is more common and the involved length is mostly more than 1/2 of the optic nerve length, whereas posterior involvement, intracranial segment, optic chiasm, or optic tract, is more common in NMOSD-ON.
PROSPERO REGISTRATION NUMBER
CRD42020222430 (25-11-2020).
PubMed: 37846325
DOI: 10.1016/j.aopr.2021.100019 -
Medicina (Kaunas, Lithuania) Sep 2023: Although ocular disorders can occasionally impact people with HIV over the course of their illness, HIV/AIDS is unmistakably a multisystem disorder. A physician can...
: Although ocular disorders can occasionally impact people with HIV over the course of their illness, HIV/AIDS is unmistakably a multisystem disorder. A physician can rule out a wide range of ophthalmic problems with the assistance of an ophthalmologist, from adnexal disorders to posterior segment diseases, including those affecting the optic tract and optic nerve. : Based on patient medical data from the "St. Parascheva" Clinical Hospital of Infectious Diseases in Iasi, we carried out a retrospective clinical investigation on patients with HIV/AIDS and ophthalmological conditions who were hospitalized in northeastern Romania. We seek to draw attention to the characteristics and ophthalmological comorbidities of HIV/AIDS patients. The studied period was between 1 January 1991 and 31 December 2022. : There were a total of 38 recorded cases of ophthalmological manifestations in the HIV-infected patients. The research group's average age was 37.31 years old (standard deviation 9.5693917). Males were primarily impacted, having lower total CD4+ T-lymphocyte levels based on sex and CD4+ T-lymphocyte levels overall. The HIV viral load was 999 268.13 copies/mL on average (standard deviation 1,653,722.9). Of all the patients, we found out that 17 had congenital eye diseases (44.73%) and the others (21, 55.26%) developed ophthalmological diseases. CMV Retinitis was found most frequently, in eight patients (21.05%), followed by Myopia in seven patients (18.42%). : The key to the management of HIV-positive patients is a multidisciplinary approach and access to antiretroviral therapy. Anyone who is HIV-positive and experiences ocular symptoms at any time should be directed to seek professional ophthalmologic treatment as soon as feasible. A therapeutic holdup could result in irreversible vision loss. Long-term coordination is required to combat this disease, improving communication between the ophthalmology and infectious disease fields.
PubMed: 37763724
DOI: 10.3390/medicina59091605 -
Journal of Neurotrauma Oct 2023Repetitive mild traumatic brain injuries (rmTBIs) are serious trauma events responsible for the development of numerous neurodegenerative disorders. A major challenge in...
Fixed Time-Point Analysis Reveals Repetitive Mild Traumatic Brain Injury Effects on Resting State Functional Magnetic Resonance Imaging Connectivity and Neuro-Spatial Protein Profiles.
Repetitive mild traumatic brain injuries (rmTBIs) are serious trauma events responsible for the development of numerous neurodegenerative disorders. A major challenge in developing diagnostics and treatments for the consequences of rmTBI is the fundamental knowledge gaps of the molecular mechanisms responsible for neurodegeneration. It is both critical and urgent to understand the neuropathological and functional consequences of rmTBI to develop effective therapeutic strategies. Using the Closed-Head Impact Model of Engineered Rotational Acceleration, or CHIMERA, we measured neural changes following injury, including brain volume, diffusion tensor imaging, and resting-state functional magnetic resonance imaging coupled with graph theory and functional connectivity analyses. We determined the effect of rmTBI on markers of gliosis and used NanoString-GeoMx to add a digital-spatial protein profiling analysis of neurodegenerative disease-associated proteins in gray and white matter regions. Our analyses revealed aberrant connectivity changes in the thalamus, independent of microstructural damage or neuroinflammation. We also identified distinct changes in the levels of proteins linked to various neurodegenerative processes including total and phospho-tau species and cell proliferation markers. Together, our data show that rmTBI significantly alters brain functional connectivity and causes distinct protein changes in morphologically intact brain areas.
Topics: Humans; Brain Concussion; Neurodegenerative Diseases; Diffusion Tensor Imaging; Brain; Brain Injuries, Traumatic; Magnetic Resonance Imaging
PubMed: 37051703
DOI: 10.1089/neu.2022.0464 -
AJNR. American Journal of Neuroradiology Sep 2019Intraocular silicone oil injection has been used to treat complicated retinal detachments, and recently its retrolaminar and intracranial migration has been reported....
BACKGROUND AND PURPOSE
Intraocular silicone oil injection has been used to treat complicated retinal detachments, and recently its retrolaminar and intracranial migration has been reported. The purpose of this study was to document the prevalence of posterior migration of intraocular silicone oil on head CT and describe the clinical and radiologic findings.
MATERIALS AND METHODS
This retrospective study included 57 patients with intraocular silicone oil injection who underwent unenhanced head CT between November 2008 and July 2018. All images were visually evaluated for subretinal and retrolaminar migration of intraocular silicone oil involving the anterior visual pathway (optic nerve, optic chiasm, and optic tract) and the ventricular system. Attenuation values of those structures were measured and compared with those of the contralateral or adjacent normal structures.
RESULTS
We detected subretinal and retrolaminar silicone oil migration in 7 of the 57 patients (12%), noting silicone oil at the optic nerve head ( = 2), retrolaminar optic nerve ( = 5), optic chiasm ( = 3), optic tract ( = 3), and in the lateral ventricles ( = 1). Attenuation values of the structures with silicone oil migration were significantly higher than those of the control regions (optic nerve head, 69.2 ± 12.4 vs 29.8 ± 10.2 HU, < .001; retrolaminar optic nerve, 59.9 ± 11.6 vs 30.9 ± 8.6 HU, < .001; optic chiasm, 74.2 ± 11.0 vs 25.6 ± 6.9 HU, < .001; optic tract, 70.1 ± 4.7 vs 28.7 ± 7.2 HU, < .001). No significant ophthalmic or neurologic complications were documented in the patients with silicone oil migration.
CONCLUSIONS
Subretinal and retrolaminar migration of intraocular silicone oil is common. Although there were no apparent complications associated with silicone oil migration, the radiologist and clinician should be aware of this phenomenon.
Topics: Adult; Female; Humans; Injections, Intraocular; Male; Middle Aged; Retinal Detachment; Retrospective Studies; Silicone Oils; Tomography, X-Ray Computed
PubMed: 31467241
DOI: 10.3174/ajnr.A6176 -
Epilepsy Research and Treatment 2012Only primates have temporal lobes, which are largest in man, accommodating 17% of the cerebral cortex and including areas with auditory, olfactory, vestibular, visual...
Only primates have temporal lobes, which are largest in man, accommodating 17% of the cerebral cortex and including areas with auditory, olfactory, vestibular, visual and linguistic functions. The hippocampal formation, on the medial side of the lobe, includes the parahippocampal gyrus, subiculum, hippocampus, dentate gyrus, and associated white matter, notably the fimbria, whose fibres continue into the fornix. The hippocampus is an inrolled gyrus that bulges into the temporal horn of the lateral ventricle. Association fibres connect all parts of the cerebral cortex with the parahippocampal gyrus and subiculum, which in turn project to the dentate gyrus. The largest efferent projection of the subiculum and hippocampus is through the fornix to the hypothalamus. The choroid fissure, alongside the fimbria, separates the temporal lobe from the optic tract, hypothalamus and midbrain. The amygdala comprises several nuclei on the medial aspect of the temporal lobe, mostly anterior the hippocampus and indenting the tip of the temporal horn. The amygdala receives input from the olfactory bulb and from association cortex for other modalities of sensation. Its major projections are to the septal area and prefrontal cortex, mediating emotional responses to sensory stimuli. The temporal lobe contains much subcortical white matter, with such named bundles as the anterior commissure, arcuate fasciculus, inferior longitudinal fasciculus and uncinate fasciculus, and Meyer's loop of the geniculocalcarine tract. This article also reviews arterial supply, venous drainage, and anatomical relations of the temporal lobe to adjacent intracranial and tympanic structures.
PubMed: 22934160
DOI: 10.1155/2012/176157 -
Developmental Medicine and Child... Mar 2019The aim of this study was to assess parameters of retinal morphology by using high-definition optical coherence tomography (OCT) in patients with Wolfram syndrome (WFS)...
AIM
The aim of this study was to assess parameters of retinal morphology by using high-definition optical coherence tomography (OCT) in patients with Wolfram syndrome (WFS) and their relation to optic tract atrophy in magnetic resonance imaging (MRI).
METHOD
High-definition OCT and MRI parameters were evaluated in 12 patients with WFS (three males, nine females; median age at examination 12y 8mo, range 10y 2mo-15y 11mo) and referred to 30 individuals with type 1 diabetes (T1D) (12 males, 18 females; median age at examination 20y 5mo, range 16y 8mo-21y 4mo) and 33 typically developing comparison participants (10 males, 23 females; median age at examination 20y 7mo, range 13y-22y 4mo).
RESULTS
Total thickness and quadrant thickness of the retinal nerve fibre layer (RNFL), macular full-thickness parameters and macular ganglion cell layer/inner plexiform layer, intraorbital and intracranial thickness of the optical nerve, as well as the optic chiasm and visual tracts were significantly reduced in patients with WFS compared with those having T1D and the typically developing comparison participants. Optic chiasm thickness correlated negatively in patients with WFS with both age (r=-0.79; p=0.002) and duration of diabetes (r=-0.62; p=0.032). Thickness of the intraorbital parts of the optic nerves in patients with WFS correlated positively with thickness of the superior RNFL (r=0.73; p=0.006).
INTERPRETATION
High-definition OCT in combination with MRI could become an important tool for evaluating the effectiveness of therapeutic trials in patients with WFS.
WHAT THIS PAPER ADDS
Provides evidence of significant reduction of retinal parameters and optic nerves in patients with Wolfram syndrome (WFS). Shows correlations between magnetic resonance imaging parameters and retinal morphology parameters in patients with WFS.
Topics: Adolescent; Child; Child, Preschool; Female; Humans; Infant; Magnetic Resonance Imaging; Male; Optic Nerve; Optic Tract; Retina; Tomography, Optical Coherence; Visual Pathways; Wolfram Syndrome; Young Adult
PubMed: 30246501
DOI: 10.1111/dmcn.14040 -
Cells Apr 2021Traumatic brain injury (TBI) results in a number of impairments, often including visual symptoms. In some cases, visual impairments after head trauma are mediated by...
Traumatic brain injury (TBI) results in a number of impairments, often including visual symptoms. In some cases, visual impairments after head trauma are mediated by traumatic injury to the optic nerve, termed traumatic optic neuropathy (TON), which has few effective options for treatment. Using a murine closed-head weight-drop model of head trauma, we previously reported in adult mice that there is relatively selective injury to the optic tract and thalamic/brainstem projections of the visual system. In the current study, we performed blunt head trauma on adolescent C57BL/6 mice and investigated visual impairment in the primary visual system, now including the retina and using behavioral and histologic methods at new time points. After injury, mice displayed evidence of decreased optomotor responses illustrated by decreased optokinetic nystagmus. There did not appear to be a significant change in circadian locomotor behavior patterns, although there was an overall decrease in locomotor behavior in mice with head injury. There was evidence of axonal degeneration of optic nerve fibers with associated retinal ganglion cell death. There was also evidence of astrogliosis and microgliosis in major central targets of optic nerve projections. Further, there was elevated expression of endoplasmic reticulum (ER) stress markers in retinas of injured mice. Visual impairment, histologic markers of gliosis and neurodegeneration, and elevated ER stress marker expression persisted for at least 30 days after injury. The current results extend our previous findings in adult mice into adolescent mice, provide direct evidence of retinal ganglion cell injury after head trauma and suggest that axonal degeneration is associated with elevated ER stress in this model of TON.
Topics: Animals; Brain Injuries, Traumatic; Disease Models, Animal; Endoplasmic Reticulum Stress; Gliosis; Male; Mice; Mice, Inbred C57BL; Neurodegenerative Diseases; Optic Nerve Injuries; Vision Disorders
PubMed: 33922788
DOI: 10.3390/cells10050996 -
Experimental and Therapeutic Medicine May 2019The present study demonstrates alterations of the contralateral side optic tract to an optic nerve traumatic lesion. Visual acuity of the right eye following Traumatic...
The present study demonstrates alterations of the contralateral side optic tract to an optic nerve traumatic lesion. Visual acuity of the right eye following Traumatic optic neuropathy (TON) remained at 0 following the injury. Electrophysiological examination using pattern electroretinogram revealed values reduced by 50% in the right eye compared with the left eye. Pattern visual-evoked potential evaluation indicated a bilateral lesion with a higher decrease following right eye stimulation. Magnetic resonance imaging revealed right optic nerve atrophy. Functional magnetic resonance imaging indicated decreased activity of the visual centre during left eye stimulation. The present study revealed contralateral visual tract alterations following unilateral injury, and hypothesize that the ganglion cells of the retina respond initially to glial activation. These changes are, in our view, followed by changes in the visual pathway.
PubMed: 31007755
DOI: 10.3892/etm.2019.7445