Department of Ophthalmology, USC Roski Eye Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, 90033, USA.
Published: March 2023
AI Article Synopsis
Article Abstract
Human studies have established that short periods of dark adaptation can induce outer retinal thinning and various band intensity changes that can be detected with Optical Coherence Tomography (OCT). Similar findings were observed in mice, including a positive correlation between the degree of outer retinal changes and dark adaptation duration. We decided to assess potential retinal structural changes following prolonged dark adaptation in humans. 40 healthy subjects without any ocular diseases participated in this study. For each subject, one eye was covered for dark adaptation for four hours, and the other eye was left uncovered as a control. Before and after the dark adaptation period, both eyes were assessed with OCT. Using the Heidelberg Spectralis system, basic statistical functions, and qualitative and quantitative analysis, we were able to compare retinal layer thicknesses and band intensities between covered (dark adapted) versus uncovered (control) eyes. Prolonged dark adaptation did not induce any significant thickness, volume, or intensity changes in the outer retina or in the inner or overall retina. These observations thus alter our current understanding of the mechanisms underlying dark adaptation's neuroprotective effects in preventing blindness and require further study.
Gavin Herbert Eye Institute - Center for Translational Vision Research, Department of Ophthalmology, University of California, Irvine, Irvine, California 92697, United States.
Arrestins halt signal transduction by binding to the phosphorylated C-termini of activated G protein-coupled receptors. Arrestin-1, the first subtype discovered, binds to rhodopsin in rod cells. Mutations in , the gene encoding Arrestin-1, are linked to Oguchi disease, characterized by delayed dark adaptation.
Background: Seed dormancy is a critical evolutionary trait that enhances the persistence of plant populations under both natural and managed conditions. It is influenced by genetic and environmental factors, with crop management practices like tillage and herbicide use reportedly selecting for increased seed dormancy in weeds. This study aimed to compare the success of seed dormancy breaking methods between weed populations collected from intensively managed crop fields and unmanaged ruderal locations.
Rhythmicity is a characteristic feature of the inanimate universe. The organization of biological rhythms in time is an adaptation to the cyclical environmental changes brought on by the earth's rotation on its axis and around the sun. Circadian (L.
Purpose: The purpose of this study was to determine the natural history of the photoreceptor disease in a large group of pediatric patients with RHD12-associated Leber congenital amaurosis (RDH12-LCA), to estimate the changes expected over the duration of a clinical trial, and to define the relationship between the photoreceptor loss and visual dysfunction.
Methods: Forty-six patients representing 36 families were included. The great majority of patients were under the age of 18 years.
The adaptation to the daily 24-h light-dark cycle is ubiquitous across animal species and is crucial for maintaining fitness. This free-running cycle occurs innately within multiple bodily systems, such as endogenous circadian rhythms in clock-gene expression and synaptic plasticity. These phenomena are well studied; however, it is unknown if and how the 24-h clock affects electrophysiologic network function in vivo.
