On the cortical connexions of the optic nerves

1884 ◽  
Vol 37 (232-234) ◽  
pp. 1-3 ◽  
Keyword(s):  
Cerebral Cortex ◽  
Optic Nerve ◽  
Cerebral Hemisphere ◽  
Optic Tract ◽  
Frontal Region ◽  
Occipital Region ◽  
Optic Nerves ◽  
Form Part ◽  
Lenticular Nucleus

1. The original statement made by Gratiolet that the optic tract is directly connected with every part of the cerebral hemisphere in man, from the frontal to the occipital region, is almost literally true. 2. The origins of the optics may he divided into two sets—ganglionic and cortical. 3. The fibres in the ganglionic set are derived from the corpora geniculata, pulvinar and corpora quadrigemina, probably also directly from the substance of the thalamus. 4. The cortical set ’join the chiasma and tract. 5. The junction of the chiasma with the cerebral cortex is brought about by means, of “Meynert’s commissure.” The latter arises from the lenticular-nucleus-loop (Linsen-kern-schlinge), decussates in the lamina cinerea, and passes with the optic nerve of the opposite side. This commissure is connected to the cortex in the frontal region by the following means:— It arises directly from the lenticular-nucleus-loop; the lenticular-nucleus-loop is formed by the junction, below the lenticular nucleus, of the striae medullares; the striae medullares form part of the fibres of the inner capsule, and the inner capsule is composed of the fibres descending from the cortex. I should think it very probable that the fibres constituting the striae medullares come from the cortex of the same side.

Distribution of uncrossed and crossed retinofugal axons in the cat optic nerve and their relationship to patterns of fasciculation

1990 ◽  
Vol 5 (1) ◽  
pp. 99-104 ◽  
Author(s):  
Glen Jeffery
Keyword(s):  
Optic Nerve ◽  
Optic Tract ◽  
Relative Increase ◽  
Lateral Aspect ◽  
Optic Nerves ◽  
Caudal Region ◽  
Lateral Extent ◽  
Optic Axons ◽  
Horseradish Peroxide ◽  
Caudal Segment

AbstractThe course of optic axons that take different routes at the chiasm have been traced through horizontally sectioned optic nerves in the cat, after unilateral injections of horseradish peroxide into the optic tract. Behind the eye and for most of the course of the nerve, nearly all of the axons that remain uncrossed at the chiasm are located in a retinotopically appropriate position, in the lateral aspect of the nerve. However, in the most caudal segment of the nerve an increasing proportion of these axons are located in regions that are retinotopically inappropriate. Just before the nerve joins the chiasm, uncrossed axons can be found across the full medio-lateral extent of the nerve, although there is still a relative increase in their density laterally.Labeled axons that cross at the chiasm course in a relatively parallel manner along the greater proportion of the nerve. However, in the caudal segment of the nerve their relative positions change and they appear to course in an irregular manner. This occurs where the uncrossed projection becomes increasingly more widespread.Axons in the optic nerve are grouped into fascicules. This pattern of organization also changes in the caudal region of the nerve. Although clear fascicular patterns are present along the greater part of the nerve, they become progressively less distinct caudally. The change in the pattern of fasciculation occurs over the same region of the nerve as the relative changes in axon trajectory and distribution.These results demonstrate that irrespective of chiasmatic route, optic axons in the cat are reorganized in the caudal segment of the nerve. This reorganization is not confined to changes in relative axon position, but is reflected in the structure of the nerve by the change of axon grouping from a fascicular to a non-fascicular arrangement.

Central origin of the efferent neurons projecting to the eyes of Limulus polyphemus

1991 ◽  
Vol 6 (5) ◽  
pp. 481-495 ◽  
Author(s):  
B. G. Calman ◽  
B.- A. Battelle
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Optic Nerve ◽  
Optic Tract ◽  
Limulus Polyphemus ◽  
Cell Of Origin ◽  
Optic Nerves ◽  
Visual Cells ◽  
Efferent Neurons ◽  
The Central Nervous System

AbstractCircadian rhythms affect the anatomy, physiology, and biochemistry of the visual cells in the eyes of the horseshoe crab (Limulus polyphemus). These rhythms are mediated by the activity of efferent neurons that project from the central nervous system to all of the eyes. In this study, the optic nerves of Limulus were backfilled with Neurobiotin revealing the location of efferent cell bodies and their projections through the central nervous system. We propose that this efferent system mediates the circadian changes in visual functions in Limulus. Whether these cells are the circadian pacemaker neurons is unknown.The cell bodies of the efferent neurons are ovoid and have a diameter of 40−80 μm. They lie within the cheliceral ganglion of the tritocerebrum, just posterior to the protocerebrum. This ganglion is on the lateral edge of the circumesophageal ring, near the middle of the dorsal-ventral axis of the ring. Each optic nerve contains axons from both ipsilateral and contralateral efferent cells, and some, possibly all, of them project bilaterally and to more than one type of optic nerve.The efferent axons form a tract that projects anteriorly from the cell bodies to the protocerebrum, and bifurcates just lateral to the protocerebral bridge. One branch crosses the midline and projects anteriorly to the optic tract and medulla on the side contralateral to the cell of origin; the other branch follows a symmetric pathway on the ipsilateral side. Small branches arising from the major efferent axons in the optic tract project through the ocellar ganglia to the median optic nerves. The efferent axons branch again in the medulla, and some of these branches innervate the ventral optic nerves. The major branches of the efferent axons continue through the lamina and enter the lateral optic nerve.

Pre-existing neuronal pathways in the developing optic lobes of Drosophila

Development ◽  
1989 ◽  
Vol 105 (4) ◽  
pp. 739-746 ◽  
Author(s):  
S. Tix ◽  
J.S. Minden ◽  
G.M. Technau
Keyword(s):  
Optic Nerve ◽  
Visual System ◽  
Optic Lobe ◽  
Adult Stage ◽  
Insertion Site ◽  
Optic Tract ◽  
Optic Stalk ◽  
Optic Lobes ◽  
First Order ◽  
Form Part

We have identified a set of larval neurones in the developing adult optic lobes of Drosophila by selectively labelling cells that have undergone only a few mitoses. A cluster of three cells is located in each of the optic lobes near the insertion site of the optic stalk. Their axons fasciculate with fibres of the larval optic nerve, the Bolwig's nerve, and then form part of the posterior optic tract. These cells are likely to be first order interneurones of the larval visual system. Unlike the Bolwig's nerve, they persist into the adult stage. The possibility of a pioneering function of the larval visual system during formation of the adult optic lobe neuropil is discussed.

Oligodendrocytes in Developing Hameter Cerebral Cortex

1976 ◽  
Vol 34 ◽  
pp. 126-127
Author(s):  
MB. Tank Buschmann
Keyword(s):  
Cerebral Cortex ◽  
Optic Nerve ◽  
Frontal Cortex ◽  
Osmium Tetroxide ◽  
Sodium Cacodylate Buffer ◽  
Sodium Cacodylate ◽  
Tissue Samples ◽  
Cacodylate Buffer ◽  
Layer V ◽  
Adult Hamster

Development of oligodendrocytes in rat corpus callosum was described as a sequential change in cytoplasmic density which progressed from light to medium to dark (1). In rat optic nerve, changes in cytoplasmic density were not observed, but significant changes in morphology occurred just prior to and during myelination (2). In our study, the ultrastructural development of oligodendrocytes was studied in newborn, 5-, 10-, 15-, 20-day and adult frontal cortex of the golden hamster (Mesocricetus auratus).Young and adult hamster brains were perfused with paraformaldehyde-glutaraldehyde in sodium cacodylate buffer at pH 7.3 according to the method of Peters (3). Tissue samples of layer V of the frontal cortex were post-fixed in 2% osmium tetroxide, dehydrated in acetone and embedded in Epon-Araldite resin.

Early Detection of Central Nervous System Relapse of Pediatric Leukemia with Measurement of Optic Nerve Sheath Diameter on MRI

2019 ◽  
Vol 15 (2) ◽  
pp. 237-241
Author(s):  
Taner Arpaci ◽  
Barbaros S. Karagun
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Optic Nerve ◽  
Early Detection ◽  
Optic Nerve Sheath Diameter ◽  
Central Nervous System Relapse ◽  
Mri Findings ◽  
Pediatric Leukemia ◽  
Optic Nerves ◽  
Cns Relapse

Background: Leukemia is the most common pediatric malignancy. Central Nervous System (CNS) is the most frequently involved extramedullary location at diagnosis and at relapse. </P><P> Objective: To determine if Magnetic Resonance Imaging (MRI) findings of optic nerves should contribute to early detection of CNS relapse in pediatric leukemia. Methods: Twenty patients (10 boys, 10 girls; mean age 8,3 years, range 4-16 years) with proven CNS relapse of leukemia followed up between 2009 and 2017 in our institution were included. Orbital MRI exams performed before and during CNS relapse were reviewed retrospectively. Forty optic nerves with Optic Nerve Sheaths (ONS) and Optic Nerve Heads (ONH) were evaluated on fat-suppressed T2-weighted TSE axial MR images. ONS diameter was measured from the point 10 mm posterior to the globe. ONS distension and ONH configuration were graded as 0, 1 and 2. Results: Before CNS relapse, right mean ONS diameter was 4.52 mm and left was 4.61 mm which were 5.68 mm and 5.66 mm respectively during CNS relapse showing a mean increase of 25% on right and 22% on left. During CNS relapse, ONS showed grade 0 distension in 15%, grade 1 in 60%, grade 2 in 25% and ONH demonstrated grade 0 configuration in 70%, grade 1 in 25% and grade 2 in 5% of the patients. Conclusion: MRI findings of optic nerves may contribute to diagnose CNS relapse by demonstrating elevated intracranial pressure in children with leukemia.

scholarly journals Novel in vivo depiction of optic nerves hemorrhages in child abuse: a 3D-SWI pilot study

2021 ◽  
Author(s):  
Giulio Zuccoli
Keyword(s):  
Optic Nerve ◽  
Mass Effect ◽  
Abusive Head Trauma ◽  
Superficial Siderosis ◽  
Susceptibility Artifacts ◽  
Female Ratio ◽  
Optic Nerves ◽  
Statistical Correlations ◽  
Post Traumatic

Abstract Purpose Until now, the diagnosis of optic nerves hemorrhages in abusive head trauma (AHT) has been obtained only in the postmortem setting. The aim of the IRB-approved study was to assess the presence of optic nerves hemorrhages in AHT patients using 3D-SWI. Methods Thirteen children with a final confirmed multidisciplinary diagnosis of AHT underwent coronal and axial 3D-SWI imaging of the orbits. The presence of optic nerve sheath (ONS) hemorrhages was defined by thickening and marked 3D-SWI hypointensity of the ONS, resulting in mass effect upon the CSF space. Optic nerve (ON) hemorrhages were defined by areas of susceptibility artifacts in the ON parenchyma. Superficial siderosis was defined by susceptibility artifact coating the ON. Furthermore, data about post-traumatic deformity of the ONS at the head of the optic nerve were collected. Results The average age of the population was 7.9 ± 5.9 months old. The average GCS was 11.8 ± 4.5. The male to female ratio was 7:6. ONS hemorrhages were identified in 69.2% of cases. Superficial siderosis and ON hemorrhages were identified in 38.5 and 76.9% of cases, respectively. 3D-SWI also depicted traumatic deformity of the ONS at the level of the optic nerve head in 10 cases (76.9%). No statistical correlations were identified between RetCam findings and 3D-SWI findings or GCS and ON hemorrhages. Conclusion This research shows that dedicated MRI with volumetric SWI of the orbits can depict hemorrhages in the ON, ONS, and ONS injury, in AHT victims.

Bilateral Intraorbital Arachnoid Cysts of the Optic Nerves and Coloboma of the Optic Nerve Ends

1984 ◽  
Vol 4 (3) ◽  
pp. 165-168 ◽  
Author(s):  
R. Wijngaarde ◽  
G. Blaauw ◽  
A. Van Balen
Keyword(s):  
Optic Nerve ◽  
Arachnoid Cysts ◽  
Optic Nerves

Fibre organization and reorganization in the retinotectal projection of Xenopus

Development ◽  
1987 ◽  
Vol 99 (3) ◽  
pp. 393-410
Author(s):  
J.S. Taylor
Keyword(s):  
Optic Nerve ◽  
Ganglion Cell ◽  
Rana Pipiens ◽  
Optic Tract ◽  
Retinal Position ◽  
Dual Representation ◽  
Optic Chiasma ◽  
Age Related ◽  
Pass Through ◽  
Radial Organization

This study concerns the retinotopic organization of the ganglion cell fibres in the visual system of the frog Xenopus laevis. HRP was used to trace the pathways taken by fibres from discrete retinal positions as they pass from the retina, along the optic nerve and into the chiasma. The ganglion cell fibres in the retina are arranged in fascicles which correspond with their circumferential positions of origin. Within the fascicles the fibres show little age-related layering and do not have a strict radial organization. As the fascicles of fibres pass into the optic nerve head there is some exchange of position resulting in some loss of the retinal circumferential organization. The poor radial organization of the fibres in the retinal fascicles persists as the fibres pass through the intraocular part of the nerve. At a position just behind the eye there is a major fibre reorganization in which fibres arising from cells of increasingly peripheral retinal locations are found to have passed into increasingly peripheral positions in the nerve. Thus, fibres from peripheral-most retina are located at the nerve perimeter, whilst fibres from central retina are located in the nerve core. It is at this point that the radial, chronotopic, ordering of the ganglion cell axons, found throughout the rest of the optic pathway, is established. This annular organization persists along the length of the nerve until a position just before the nerve enters the brain. Here, fibres from each annulus move to form layers as they pass into the optic chiasma. This change in the radial organization appears to be related to the pathway followed by all newly growing fibres, in the most superficial part of the optic tract, adjacent to the pia. Just behind the eye, where fibres become radially ordered, the circumferential organization of the projection is largely lost. Fibres from every circumferential retinal position, which are of similar radial position, are distributed within the same annulus of the nerve. At the nerve-chiasma junction where each annulus forms a single layer as it enters the optic tract, there is a further mixing of fibres from all circumferential positions. However, as the fibres pass through the chiasma some active pathway selection occurs, generating the circumferential organization of the fibres in the optic tract. Additional observations of the organization of fibres in the optic nerve of Rana pipiens confirm previous reports of a dual representation of fibres within the nerve. The difference in the organization of fibres in the optic nerve of Xenopus and Rana pipiens is discussed.

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