Control of retinal growth and axon divergence at the chiasm: lessons fromXenopus

BioEssays ◽  
2001 ◽  
Vol 23 (4) ◽  
pp. 319-326 ◽  
Author(s):  
Fanny Mann ◽  
Christine E. Holt
Keyword(s):  
Retinal Growth

scholarly journals N-myc coordinates retinal growth with eye size during mouse development

2008 ◽  
Vol 22 (2) ◽  
pp. 179-193 ◽  
Author(s):  
R. A.P. Martins ◽  
F. Zindy ◽  
S. Donovan ◽  
J. Zhang ◽  
S. Pounds ◽  
...  
Keyword(s):  
Mouse Development ◽  
Eye Size ◽  
Retinal Growth

Retinal growth in double dorsal and double ventral eyes in Xenopus

Development ◽  
1977 ◽  
Vol 40 (1) ◽  
pp. 175-185
Author(s):  
K. Straznicky ◽  
D. Tay
Keyword(s):  
Xenopus Laevis ◽  
Compound Eye ◽  
Ganglion Cells ◽  
Cell Number ◽  
Early Embryogenesis ◽  
Time Points ◽  
Retinal Growth

The growth of normal and surgically produced compound dorsal and ventral retinae in Xenopus laevis has been studied autoradiographically following injections of [3H]thymidine at stages 50 and 58. The animals were sacrificed 3 weeks after metamorphosis. The histogenetic pattern of the dorsal and ventral retinal halves was different at the three time points investigated, i.e. up to stage 50, between stages 50 and 58 and between stage 58 and 3 weeks after metamorphosis. Asymmetrical dorsal retinal growth occurred up to stage 50. From stage 50 onwards the retinal growth tendency reversed so that more ganglion cells were produced along the ventral than the dorsal ciliary margins. The overall preponderance of ventral retinal growth was 32·4% in cell number and 12·4% in retinal length from early embryogenesis to 3 weeks after metamorphosis. The characteristic histogenetic pattern of the dorsal and ventral retinal halves was maintained in an ectopic position in the compound eye, indicating that this particular property of the retinal halves is intrinsically determined.

The effect of retinal growth on the postnatal development and distribution of displaced retinal ganglion cells in the retina of the chameleon (squamata)

2003 ◽  
Vol 20 (3) ◽  
pp. 273-283 ◽  
Author(s):  
MATTHIAS OTT ◽  
BRENO BELLINTANI-GUARDIA
Keyword(s):  
Retinal Ganglion Cells ◽  
Ganglion Cells ◽  
Retrograde Transport ◽  
Dendritic Arbor ◽  
Adult Size ◽  
Retinal Ganglion ◽  
Accessory Optic System ◽  
Dendritic Field ◽  
Eye Size ◽  
Retinal Growth

Retinal ganglion cells (RGCs) usually increase their dendritic field area with postnatal retinal growth. The mechanisms that regulate the postnatal shape of dendritic arbors in the growing retina are not well understood. Quantitative studies suffer from the difficulty of labeling specific subpopulations of RGCs selectively including their dendritic processes. In this study, we labeled displaced retinal ganglion cells (DGC) that are known to project to the accessory optic system (AOS) in juvenile and adult chameleons by retrograde transport of dextran amines. The complete population of DGCs was quantitatively screened for the effects of postnatal retinal growth on cell morphology, dendritic field coverage, and dendritic arbor size. The adult eye contained 2000 DGCs/retina. This number was already present at birth. The smaller size of the hatchling eye (approximately 1/3 of the adult size) led to higher densities of DGCs. The greatest accumulation of juvenile DGCs (two-fold higher compared to the adult) was found in the periphery of the retina where the greatest surface expansion was observed. DGC dendritic field areas were adjusted proportionally to this expansion in order to maintain a constant dendritic coverage. The increase of dendritic fields was mediated by two putative passive mechanisms: First, an elongation of individual dendrites similar to previous reports of postnatal RGC development in the retina of goldfish and chicks. Second, and more prominent, we observed that neighboring dendrites were pulled apart from each other. This resulted in a looser spacing of the initially tightly packed dendrites of each dendritic arbor. This dispersal of dendrites over a larger area was, due to its passive nature, proportional to the increase of the retinal surface and preserved a constant dendritic coverage irrespective of the animal's age and eye size.

The role of the retinal pigment epithelium in eye growth regulation and myopia: A review

2005 ◽  
Vol 22 (3) ◽  
pp. 251-261 ◽  
Author(s):  
JODI RYMER ◽  
CHRISTINE F. WILDSOET
Keyword(s):  
Retinal Pigment Epithelium ◽  
Growth Regulation ◽  
Fluid Transport ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Critical Role ◽  
Growth Modulation ◽  
Eye Growth ◽  
Retinal Growth ◽  
Growth Changes

Myopia is increasing in prevalence world-wide, nearing epidemic proportions in some populations. This has led to expanded research efforts to understand how ocular growth and refractive errors are regulated. Eye growth is sensitive to visual experience, and is altered by both form deprivation and optical defocus. In these cases, the primary targets of growth regulation are the choroidal and scleral layers of the eye that demarcate the boundary of the posterior vitreous chamber. Of significance to this review are observations of local growth modulation that imply that the neural retina itself must be the source of growth-regulating signals. Thus the retinal pigment epithelium (RPE), interposed between the retina and the choroid, is likely to play a critical role in relaying retinal growth signals to the choroid and sclera. This review describes the ion transporters and signal receptors found in the chick RPE and their possible roles in visually driven changes in eye growth. We focus on the effects of four signaling molecules, otherwise implicated in eye growth changes (dopamine, acetylcholine, vasoactive intestinal peptide (VIP), and glucagon), on RPE physiology, including fluid transport. A model for RPE-mediated growth regulation is proposed.

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