Birth dates of retinal ganglion cells giving rise to the crossed and uncrossed optic projections in the mouse

In the mouse, as in most mammals, the crossed optic projections originate from the entire extent of the retina, whereas ganglion cells giving rise to the uncrossed (ipsilateral) projection are restricted to the temporal and ventral retina. The nasal border of this bilaterally projecting region in the retina corresponds to the midline of the visual field. Here the birth dates of ipsilaterally and contralaterally projecting ganglion cells were determined by combining tritiated thymidine labelling in the embryo with horseradish peroxidase tracings from the optic tract in the adult. Contralaterally projecting ganglion cells were found to be generated from embryonic day E11 to about E19 in a crude concentric fashion with the oldest cells in central and youngest ones in peripheral retina. Ipsilaterally projecting cells were born from E11 to E16, that is, during the earlier part of the period in which the contralateral projection was born. At the earliest time of ganglion cell generation (E11-12 ) ipsi- and contralaterally projecting cells were born within separate retinal regions, with the future midline representation forming the border between the two zones. This distinction became lost after E13, when both ipsi- and contralaterally projecting cells were born in the bilaterally projecting region. Hence at E11-12 the retina was found to have a bipartite organization that may allow the specification of the two maps of opposite topographical polarity in which the crossed and uncrossed projections are organized. Since in the adult retina this bipartite organization is preserved only in the large ganglion cells that project to the lateral geniculate nucleus, and since large ganglion cells are known to be the earliest ones formed in the mouse, these cells may be the ones that establish the early and bilateral projections of the retina. The conclusion that the bilateral projection system in the retina reflects an early developmental programme, and not the result of competition between the two eyes at later stages, was reinforced by observing a practically normal retinal origin of ipsilateral projections in mice which had only one normal eye from the earliest stages of eye development.

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The ipsilateral retinal projection in the fat-tailed dunnart, Sminthopsis crassicaudata

Visual Neuroscience ◽

10.1017/s095252389815407x ◽

1998 ◽

Vol 15 (4) ◽

pp. 677-684 ◽

Cited By ~ 4

Author(s):

J. RODGER ◽

S.A. DUNLOP ◽

L.D. BEAZLEY

Keyword(s):

Ganglion Cells ◽

Visual Fields ◽

Optic Tract ◽

Retinal Ganglion ◽

Retinal Projection ◽

Binocular Field ◽

Sminthopsis Crassicaudata ◽

Area Centralis ◽

Ipsilateral Projection ◽

The Brain

The population of retinal ganglion cells which project ipsilaterally in the brain was examined in the fat-tailed dunnart, Sminthopsis crassicaudata, following injection of horseradish peroxidase into one optic tract. Retinae were examined as wholemounts and optic nerves as serial sections. In addition, visual fields were measured ophthalmoscopically. Ipsilaterally projecting ganglion cells were located temporal to a line which ran vertically through the middle of the area centralis and extended medially to define a ventrolateral crescent. Temporal to the naso-temporal division, a mean of 77% of ganglion cells projected ipsilaterally; these cells represented 20% of the total ganglion cell population. The magnitude and retinal location of the ipsilateral projection correlated with the extensive binocular field which measured 180 deg in the vertical (from 20 deg below the horizontal axis to 70 deg beyond the zenith) and 140 deg in horizontal meridian. Ipsilaterally projecting axons were restricted to the lateral third of the optic nerve along its length, sharing territory with contralaterally projecting axons.

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Fibre order in the normal Xenopus optic tract, near the chiasma

Development ◽

10.1242/dev.83.1.1 ◽

1984 ◽

Vol 83 (1) ◽

pp. 1-14

Author(s):

J. W. Fawcett ◽

J. S. H. Taylor ◽

R. M. Gaze ◽

P. Grant ◽

E. Hirst

Keyword(s):

Optic Nerve ◽

Small Groups ◽

Optic Nerve Head ◽

Tritiated Thymidine ◽

Optic Tract ◽

Peripheral Retina ◽

Retinal Lesions ◽

Dorsal Retina

In juvenile Xenopus retinotopic fibre order in the optic tract near the chiasma was investigated by labelling small groups of optic fibres from peripheral retina with HRP. This selective fibre labelling with HRP was combined with autoradiography following administration of tritiated thymidine to the eye, so that the HRP-labelled fibres could be located within the borders of the optic tract. Fibres arising from the periphery of all four retinal quadrants were superficially located in the optic tract near the chiasma, with dorsal retinal fibres showing the greatest tendency to travel deep in the diencephalon. Retinal lesions closer to the optic nerve head labelled fibres which ran deeper in the optic tract. Near the chiasma, fibres from ventral retina tended to group rostrally while fibres from dorsal retina tended to group caudally. However, no obvious localization of fibres arising in temporal or nasal retina was seen in the lower optic tract.

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The development of the pattern of retinal ganglion cells in the chick retina: mechanisms that control differentiation

Development ◽

10.1242/dev.126.24.5713 ◽

1999 ◽

Vol 126 (24) ◽

pp. 5713-5724 ◽

Cited By ~ 13

Author(s):

K.L. McCabe ◽

E.C. Gunther ◽

T.A. Reh

Keyword(s):

Cell Differentiation ◽

Ganglion Cell ◽

Retinal Ganglion Cells ◽

Ganglion Cells ◽

Receptor Activation ◽

Peripheral Retina ◽

Retinal Ganglion ◽

Fgf Receptor ◽

Chick Retina ◽

Regular Arrays

Neurons in both vertebrate and invertebrate eyes are organized in regular arrays. Although much is known about the mechanisms involved in the formation of the regular arrays of neurons found in invertebrate eyes, much less is known about the mechanisms of formation of neuronal mosaics in the vertebrate eye. The purpose of these studies was to determine the cellular mechanisms that pattern the first neurons in vertebrate retina, the retinal ganglion cells. We have found that the ganglion cells in the chick retina develop as a patterned array that spreads from the central to peripheral retina as a wave front of differentiation. The onset of ganglion cell differentiation keeps pace with overall retinal growth; however, there is no clear cell cycle synchronization at the front of differentiation of the first ganglion cells. The differentiation of ganglion cells is not dependent on signals from previously formed ganglion cells, since isolation of the peripheral retina by as much as 400 μm from the front of ganglion cell differentiation does not prevent new ganglion cells from developing. Consistent with previous studies, blocking FGF receptor activation with a specific inhibitor to the FGFRs retards the movement of the front of ganglion cell differentiation, while application of exogenous FGF1 causes the precocious development of ganglion cells in peripheral retina. Our observations, taken together with those of previous studies, support a role for FGFs and FGF receptor activation in the initial development of retinal ganglion cells from the undifferentiated neuroepithelium peripheral to the expanding wave front of differentiation.

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Pathways of regenerated retinotectal axons in goldfish

Development ◽

10.1242/dev.93.1.1 ◽

1986 ◽

Vol 93 (1) ◽

pp. 1-28

Author(s):

Claudia A. O. Stuermer

Keyword(s):

Optic Nerve ◽

Retinal Ganglion Cells ◽

Normal Development ◽

Ganglion Cells ◽

Optic Tract ◽

Spatiotemporal Pattern ◽

Retinal Ganglion ◽

Retinal Axons ◽

Age Related ◽

Regenerated Fibres

This study investigates the order of regenerating retinal axons in the goldfish. The spatiotemporal pattern of axon regrowth was assessed by applying horseradish peroxidase (HRP) to regenerating axons in the optic tract at various times after optic nerve section and by analysing the distribution of retrogradely labelled ganglion cells in retina. At all regeneration stages labelled ganglion cells were widely distributed over the retina. There was no hint that axons from central (older) ganglion cells might regrow earlier, and peripheral (younger) ganglion cells later, as occurs in normal development. The absence of an age-related ordering in the regenerated optic nerve was demonstrated by labelling a few axon bundles intraorbitally with HRP (Easter, Rusoff & Kish, 1981) caudal to the previous cut. The retrogradely labelled cells in retina were randomly distributed in regenerates andnot clustered in annuli as in normals. Tracing regenerating axons which were stained anterogradelyfrom intraretinal HRP applications or retrogradely from single labelled tectal fascicles illustrated the fact that the regenerating axons coursed in abnormal routes in the optic nerve and tract. On the surface of the tectum regenerated fibres re-established a fascicle fan. The retinal origin of tectal fascicles was assessed by labelling individual peripheral, intermediate and rostral fascicles with HRP. The retrogradely labelled ganglion cells in the retina were often more widely distributed than in normals, but were mostly found in peripheral, intermediate and central retina, respectively. The order of fibre departure from each tectal fascicle was revealed by placing HRP either on the fascicle's proximal or on its distal half. With proximal labelling sites labelled ganglion cells were found in the temporal and nasal retina, and with distal labelling sites labelled ganglion cells were confined to nasal retina only. Further, the axonal trajectories of anterogradely labelled dorsotemporal retinal ganglion cells were compared to those of dorsonasal retinal ganglion cells in tectal whole mounts. Dorsotemporal axons were confined to the rostral tectal half, whereas dorsonasal axons followed fascicular routes into the fascicles' distal end and reached into caudal tectum. This suggests that the fibres exited along their fascicle's course in a temporonasal sequence. Thus in the tectum, fibres in fascicles restore a gross spatial and age-related order and tend to follow their normal temporonasal sequence of exit.

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Abnormally high variability in the uncrossed retinofugal pathway of mice with albino mosaicism

Development ◽

10.1242/dev.101.4.857 ◽

1987 ◽

Vol 101 (4) ◽

pp. 857-867 ◽

Cited By ~ 1

Author(s):

R.W. Guillery ◽

G. Jeffery ◽

B.M. Cattanach

Keyword(s):

Retinal Ganglion Cells ◽

Ganglion Cells ◽

Gene Dosage ◽

Optic Tract ◽

High Variability ◽

Retinal Ganglion ◽

Rare Occurrence ◽

Autosome Translocation ◽

Open Question ◽

The Relationship

Female mice showing albino mosaicism due to an X-autosome translocation [Is(In7;X)Ct] have been studied in order to investigate the relationship between the distribution of melanin and the formation, early in development, of the abnormally small uncrossed retinofugal pathway characteristically found in all albino mammals. Earlier evidence indicates that cells normally bearing melanin play a role in producing the abnormality. In the mosaic mice, the albino gene is expressed in only about half of the cells due to random X-inactivation and the patches of normal and albino cells are extremely small relative to total retinal size (less than 1/50). We argued that if all the cells that would normally bear melanin play a role in producing the albino abnormality then the mosaic mice would have a pathway abnormality, about half the size of that in the albino mice. If, however, only a small patch of these cells plays a role, as has been proposed in earlier studies, then one would expect the size of the uncrossed pathway to be highly variable in the mosaic mice. The size of the uncrossed pathway was assessed by placing horseradish peroxidase in the region of the optic tract and lateral geniculate nucleus unilaterally and then counting the number of retrogradely labelled retinal ganglion cells on the same side. The mosaic mice showed a highly variable uncrossed pathway. In some of the mosaic mice, it was the same size as in the albinos and, in others, it was the same size as in normally pigmented mice. Surprisingly, in a small number of mosaic mice, the uncrossed pathway was larger than normal. Whether this relatively rare occurrence of a supernormal uncrossed pathway is due to the higher gene dosage or to the translocation itself remains an open question.

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Distribution of Retinal Ganglion Cells Projecting into the Nucleus of the Optic Tract in Rat

Neurophysiology of the Vestibular System - Advances in Oto-Rhino-Laryngology ◽

10.1159/000416038 ◽

2015 ◽

pp. 95-97

Author(s):

Tamotu Urushibata ◽

Isao Kato ◽

Tomoyuki Okada ◽

Isamu Takeyama

Keyword(s):

Retinal Ganglion Cells ◽

Ganglion Cells ◽

Optic Tract ◽

Retinal Ganglion

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Retinal Ganglion Cell Axon Wiring Establishing the Binocular Circuit

Annual Review of Vision Science ◽

10.1146/annurev-vision-091517-034306 ◽

2020 ◽

Vol 6 (1) ◽

pp. 215-236

Author(s):

Carol Mason ◽

Nefeli Slavi

Keyword(s):

Ganglion Cell ◽

Retinal Ganglion Cell ◽

Molecular Mechanisms ◽

Pigment Epithelium ◽

Retinal Pigment ◽

Optic Tract ◽

Optic Chiasm ◽

Retinal Ganglion ◽

Temporal Features ◽

Ipsilateral Projection

Binocular vision depends on retinal ganglion cell (RGC) axon projection either to the same side or to the opposite side of the brain. In this article, we review the molecular mechanisms for decussation of RGC axons, with a focus on axon guidance signaling at the optic chiasm and ipsi- and contralateral axon organization in the optic tract prior to and during targeting. The spatial and temporal features of RGC neurogenesis that give rise to ipsilateral and contralateral identity are described. The albino visual system is highlighted as an apt comparative model for understanding RGC decussation, as albinos have a reduced ipsilateral projection and altered RGC neurogenesis associated with perturbed melanogenesis in the retinal pigment epithelium. Understanding the steps for RGC specification into ipsi- and contralateral subtypes will facilitate differentiation of stem cells into RGCs with proper navigational abilities for effective axon regeneration and correct targeting of higher-order visual centers.

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