Light cycle--dependent axial variations in frog rod outer segment structure

Journal Article · Tue Sep 01 00:00:00 EDT 1981 · Invest. Ophthalmol. Visual Sci.; (United States)

OSTI ID:5465003

Kaplan, M W

Polarized light microscopy reveals that the structural parameters of Rana pipiens rod outer segments (ROS) are not uniform along the cell axis. In addition to a pronounced birefringence (delta n) gradient found in the basal half of most ROS, periodic delta n bands are seen in approximately 10% of intact ROS isolated by agitating retinas in frog Ringer's solution. These small delta n differences appear as very faint light and dark striations that have a period and width that depends on the duration of light and dark exposure. In ROS from frogs kept on a 14 hr light/10 hr dark cycle at 20 degrees to 22.5 degrees C, the band period for a light-dark band pair is 1.0 to 1.6 micron. Portions of ROS produced during total darkness or constant light are free of distinct periodic bands. Quantitative delta n measurements show that the ROS sections generated in the dark have a relatively higher delta n than those produced in light. Band contrast is irreversibly enhanced when ROS are treated with the calcium ionophore A23187 in the presence of calcium-free saline solution. These results indicate that the synthesis of some calcium-sensitive ROS component is different when the frog is in the dark than when exposed to light.

• OSTI ID: 5465003
• Journal Information: Invest. Ophthalmol. Visual Sci.; (United States), Vol. 21:3
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
RETINA
MORPHOLOGY
BIOCHEMISTRY
BIOLOGICAL ADAPTATION
BIOLOGICAL PATHWAYS
BIOSYNTHESIS
FROGS
OPTICAL MICROSCOPY
PHOTOSENSITIVITY
VISION
AMPHIBIANS
ANIMALS
AQUATIC ORGANISMS
BODY
BODY AREAS
CHEMISTRY
EYES
FACE
HEAD
MICROSCOPY
ORGANS
SENSE ORGANS
SENSITIVITY
SYNTHESIS
VERTEBRATES
550800* - Morphology