Purchase this article with an account.
N. Cuenca, L. Fernández-Sánchez, G. Esquiva, J. Martín-Nieto, P. Lax; Morphological and Functional Characterization of the Octodon degus Retina. Invest. Ophthalmol. Vis. Sci. 2010;51(13):891.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
The outer nuclear layer thickness ranged from 2 rows of photoreceptors at the ora serrata to 4-5 rows in the central retina. The inner nuclear layer contained 3-4 rows of neurons. Recoverin, ChAT, TH and connexin36 showed cellular immunoreactivity patterns similar to other mammalian retinas. However, horizontal cells were labeled with antibodies to parvalbumin, as in the primate retina, but also to calbindin, as in other rodents. PKCα was found in rod bipolar cells and a subtype of amacrine cells, as expected, but also in a cone bipolar cell subtype and the outer segments of blue cones. Finally, a substance P-immunoreactive plexus was found at the stratum S5 of the IPL, as a difference with other mammals. ERG a- and b-wave thresholds were higher in dark-adapted Octodon degus (0.8 ± 0.1 and 2.1 ± 0.1 log cds/m2, respectively) as compared with rats (-1.7 ± 0.1 and < -3 log cds/m2, respectively) and mice (-1.0 ± 0.1 and < -3 log cds/m2, respectively). Moreover, the double-flash protocol showed percentages of cone contribution to the mixed dark-adapted a- and b-waves over fivefold higher in Octodon degus than those found in rats and mice. Finally, Octodon had a significantly higher flicker fusion (> 50 Hz) than that observed in rats (35.2 ± 4.2 Hz) and mice (42.5 ± 2.7 Hz).
The Octodon degus retina exhibits a number of differences compared with nocturnal rodents regarding visual function, morphological features and cellular characteristics, but also several similitudes to diurnal animals. Therefore, it constitutes an interesting experimental subject for retinal research.
This PDF is available to Subscribers Only