Publication: Retinal photoreceptor fine structure in the red-backed salamander (Plethodon cinereus)
Loading...
Date
1992
Authors
Braekevelt, Charlie R.
item.page.secondaryauthor
item.page.director
Publisher
Murcia : F. Hernández
publication.page.editor
publication.page.department
DOI
item.page.type
info:eu-repo/semantics/article
Description
Abstract
The retinal photoreceptors of the red-backed
salamander (Plethodon cinerus) have been studied by
light and electron microscopy. Rods and single cones are
present in this duplex retina in a ratio of about 25: 1. The
photoreceptors in this amphibian species are much larger
than is reported for most vertebrates. In the light-adapted
state, rods reach deep into the retinal epithelial (RPE)
layer. The rod outer segment is composed of discs of
uniform diameter displaying severa1 very deep incisors.
The rod inner segment displays a dista1 elliposid of
mitochondria and a short stout myoid region. Rod nuclei
are electron dense and often protrude through the extemal
limiting membrane. Rod synaptic spherules are large and
display severa1 invaginated synaptic sites as well as
superficial synapses. It is felt that the rods do not
undergo retinomotor movements. The cone
photoreceptors are much smaller than the rods and
display a tapering outer segment, an unusual modified
ellipsoid and a large parabolid of glycogen in the inner
segment. Cone nuclei are less electron dense than rods
and are located at al1 levels within the outer nuclear layer.
The synaptic pedicle of the cones is larger, more electron
lucent and display more synaptic sites (both invaginated
and superficial) than that of rods. It is felt that cone
photomechanical responses are minimal.
publication.page.subject
Citation
item.page.embargo
Ir a Estadísticas
Sin licencia Creative Commons.