scholarly journals Multiple areas of acute vision in two freshwater teleosts, the creek chub, Semotilus atromaculatus (Mitchill) and the cutlips minnow, Exoglossum maxillingua (Lesueur)

1994 ◽  
Vol 72 (4) ◽  
pp. 721-730 ◽  
Author(s):  
Shaun P. Collin ◽  
M. Ather Ali

The topography of Nissl-stained cells within the retinal ganglion cell layer is examined in two closely related freshwater teleosts from the family Cyprinidae. Regardless of the close phylogenetic relationship and the sympatric habitats of the two species, pronounced differences in the number and position of areas of increased cell density are observed in their retinae. in the creek chub, Semotilus atromaculatus, a midwater crepuscular feeder, three retinal specializations or areae centrales are identified in the dorsonasal, nasal, and temporal regions of the retina. In the cutlips minnow, Exoglossum maxillingua, a benthic diurnal feeder, two areae centrales are identified in temporal and nasal retina. The upper limits of the spatial resolving power of each species are calculated from the spacing of cells within the ganglion cell layer. Differences in the arrangement of isodensity contours appear to reflect the symmetry of each species' visual environment. The development and significance of up to three visually acute zones are discussed.

2006 ◽  
Vol 23 (2) ◽  
pp. 257-273 ◽  
Author(s):  
HELENA J. BAILES ◽  
ANN E.O. TREZISE ◽  
SHAUN P. COLLIN

Australian lungfishNeoceratodus forsterimay be the closest living relative to the first tetrapods and yet little is known about their retinal ganglion cells. This study reveals that lungfish possess a heterogeneous population of ganglion cells distributed in a horizontal streak across the retinal meridian, which is formed early in development and maintained through to adult stages. The number and complement of both ganglion cells and a population of putative amacrine cells within the ganglion cell layer are examined using retrograde labelling from the optic nerve and transmission electron-microscopic analysis of axons within the optic nerve. At least four types of retinal ganglion cells are present and lie predominantly within a thin ganglion cell layer, although two subpopulations are identified, one within the inner plexiform and the other within the inner nuclear layer. A subpopulation of retinal ganglion cells comprising up to 7% of the total population are significantly larger (>400 μm2) and are characterized as giant or alpha-like cells. Up to 44% of cells within the retinal ganglion cell layer represent a population of presumed amacrine cells. The optic nerve is heavily fasciculated and the proportion of myelinated axons increases with body length from 17% in subadults to 74% in adults. Spatial resolving power, based on ganglion cell spacing, is low (1.6–1.9 cycles deg−1,n= 2) and does not significantly increase with growth. This represents the first detailed study of retinal ganglion cells in sarcopterygian fish, and reveals that, despite variation amongst animal groups, trends in ganglion cell density distribution and characteristics of cell types were defined early in vertebrate evolution.


2015 ◽  
Vol 56 (10) ◽  
pp. 6095 ◽  
Author(s):  
Francisco M. Nadal-Nicolás ◽  
Paloma Sobrado-Calvo ◽  
Manuel Jiménez-López ◽  
Manuel Vidal-Sanz ◽  
Marta Agudo-Barriuso

2019 ◽  
Vol 19 (10) ◽  
pp. 41c
Author(s):  
Kara N Cloud ◽  
Min Chen ◽  
Jessica I. W. Morgan ◽  
Geoffrey K. Aguirre

1992 ◽  
Vol 9 (3-4) ◽  
pp. 389-398 ◽  
Author(s):  
Luiz R. G. Britto ◽  
Dȃnia E. Hamassaki-Britto

AbstractA small number of enkephalin-like immunoreactive cells were observed in the ganglion cell layer of the pigeon retina. Many of these neurons were identified as ganglion cells, since they were retrogradely labeled after injections of fluorescent latex microspheres in the contralateral optic tectum. These ganglion cells were mainly distributed in the inferior retina, and their soma sizes ranged from 12–26 μm in the largest axis. The enkephalin-containing ganglion cells appear to represent only a very small percentage of the ganglion cells projecting to the optic tectum (less than 0.1%). Two to 7 weeks after removal of the neural retina, there was an almost complete elimination of an enkephalin-like immunoreactive plexus in layer 3 of the contralateral, rostrodorsal optic tectum. These data provide evidence for the existence of a population of enkephalinergic retinal ganglion cells with projections to the optic tectum.


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