Multinucleated cells in the retinal pigment epithelium: A scanning electron microscopic study

Puzzolo, Domenico; Simone, I. De

doi:10.1007/bf01917902

Cited by 5 publications

(1 citation statement)

References 9 publications

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“…These studies fall into several categories: (1) studies of retinal and photoreceptor development of chick embryos (Breipohl et al, 1973(Breipohl et al, , 1974aMeller and Tetzlaff, 1976;Olson, 1975Olson, , 1977Olson, , 1979 and newborn albino rats (Galbavy and Olson, 1979;Garcia-Porrero and Ojeda, 1979); (2) studies of adult mammalian retina-normal and also in various experimental conditions-of albino rats (Hansson, 1970a-e;Leuenberger, 1971;Puzzola et al, 1978;Puzzola and de Simone, 1979), rabbits (Aoki, 1974;Antal, 1977;Borwein et al, 1976Borwein et al, , 1977aLeuenberger, 1971;Miki et al, 1976;Newton et al, 1980), mouse (Smith, 19731, and cattle (Molday, 1976); (3) descriptions of amphibian retinas of bullfrog (Steinberg, 19731, Necturus (mudpuppy) (Lewis et al, 19691, and newt (Dickson and Hollenberg, 1971); (4) studies of dark-and light-adapted retinas of fish (Ali and Wagner, 1976;Borwein and Hollenberg, 1973;Pietzch-Rohrschneider, 1976); (5) studies partly or wholly describing the pigment epithelium of albino rats (Hansson, 1970a;Leuenberger, 1971;Puzzola et al, 1978;Puzzola and de Simone, 19791, chickens (Breipohl et al, 1973), rabbit (Borwein et al, 1977a;Leuenberger, 1971;Miki et al, 19761, bullfkog (Steinberg, 19731, and man (Goldbaum and Madden, 1982).…”

Section: Observationsmentioning

confidence: 98%

Scanning electron microscopy of monkey foveal photoreceptors

Borwein

1983

Anat. Rec.

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Rhesus monkey retina and especially the foveal photoreceptors (PR) were investigated by scanning electron microscopy (SEM). There are a few scattered SEM photomicrographs of the primate retina in the literature but this is the first detailed and comprehensive view by SEM of a primate retina. Some new aspects of surface morphology are displayed and the study also highlights and emphasizes some aspects of photoreceptor structure that have either been overlooked or not clearly displayed in studies using transmission electron microscopy only. For examination by SEM retinas were fixed in glutaraldehyde-formaldehyde, osmicated, immersed in thiocarbohydrazide, dehydrated in alcohols, and gold-coated. The fovea appears as a sharply defined pit with steep slopes, and its vitreal surface looks different from that of the rest of the retina. It appears to have a matted surface. The rest of the vitreal surface is relatively smooth and displays distinct lines which diverge in a radiating pattern from the foveal slopes. The choroid has a spongelike appearance; the sclera appears fibrous with the fibers running parallel to the vitreal surface. Photoreceptor nuclei are sometimes lost during tissue processing. They leave a discrete "nuclear nest" formed from Müller cell processes. Henle fibers turn at a sharp angle from the cones to run parallel to the vitreal surface. The external limiting membrane is seen as a clear line. Immediately vitreal to it, the Müller cell microvilli surround the proximal inner segments. The cone inner segment (CIS) narrows toward the cilium where the cell is markedly constricted. The ciliary connectives are aligned and appear as a shadowy, slightly wavy zone when the retina is viewed in vertical section. The freestanding, tapering calycal processes (CP) arise from and are continuous with longitudinal CIS ridges. CP surround the proximal parts of the outer segments (OS), but there are no CP around the ciliary backbone. Some CP bear small protrusions. OS break off and remain embedded among the pigment epithelium microvilli (PEM) more often than PEM remain attached to OS distal ends. The foveal OS tapers slightly from its proximal to its distal end. The OS may bear knoblike swellings and convolutions in their more distal regions but not at their tips.

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