Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
2003-5-22
pubmed:abstractText
The degu (Octodon degus) is a diurnal rodent, native to Chile. Basic features of vision and visual organization in this species were examined in a series of anatomical, electrophysiological and behavioral experiments. The lens of the degu eye selectively absorbs short-wavelength light and shows a progressive increase in optical density as a function of age. Electroretinograms recorded using a flicker-photometric procedure reveal three spectral mechanisms: a rod with peak sensitivity of about 500 nm and two types of cone having respective spectral peaks of about 362 nm and 507 nm. Opsin antibody labeling was used to determine the retinal distributions of the three receptor types. A total of about one-third of the approximately 9 million photoreceptors of the degu retina are cones with the two types (507 nm/362 nm) represented in a ratio of about 13:1. The contributions to vision of all three receptor types were examined in a series of behavioral experiments. A consistent feature of both the electrophysiological and behavioral results is that relatively high levels of light adaptation are required to effect the full transition from rod-based to cone-based vision. In behavioral tests degus were shown to be able to make color discriminations between ultraviolet and visible lights.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0340-7594
pubmed:author
pubmed:issnType
Print
pubmed:volume
189
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
347-61
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed-meshheading:12679876-Adaptation, Ocular, pubmed-meshheading:12679876-Aging, pubmed-meshheading:12679876-Animals, pubmed-meshheading:12679876-Contrast Sensitivity, pubmed-meshheading:12679876-Discrimination (Psychology), pubmed-meshheading:12679876-Electroretinography, pubmed-meshheading:12679876-Evoked Potentials, Visual, pubmed-meshheading:12679876-Female, pubmed-meshheading:12679876-Lens, Crystalline, pubmed-meshheading:12679876-Male, pubmed-meshheading:12679876-Photic Stimulation, pubmed-meshheading:12679876-Psychophysics, pubmed-meshheading:12679876-Retinal Cone Photoreceptor Cells, pubmed-meshheading:12679876-Retinal Rod Photoreceptor Cells, pubmed-meshheading:12679876-Rod Opsins, pubmed-meshheading:12679876-Rodentia, pubmed-meshheading:12679876-Sensory Thresholds, pubmed-meshheading:12679876-Spectrophotometry, Ultraviolet, pubmed-meshheading:12679876-Ultraviolet Rays, pubmed-meshheading:12679876-Vision, Ocular
pubmed:year
2003
pubmed:articleTitle
Visual adaptations in a diurnal rodent, Octodon degus.
pubmed:affiliation
Neuroscience Research Institute, University of California, Santa Barbara, CA 93106, USA. jacobs@psych.ucsb.edu
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, P.H.S.