Document Detail


Characteristics of period doubling in the rat cone flicker ERG.
MedLine Citation:
PMID:  19840785     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
When the eye is stimulated by a flickering light, the electroretinogram (ERG) and other electrophysiological responses in the visual pathway often exhibit period doubling. This phenomenon is manifested as an alternation in the shape of the response waveform from cycle to cycle, and also as spectral components at the half-fundamental frequency (F/2) and its odd multiples. Although period doubling has been described in humans as well as in other animals, its features in the rodent flicker ERG have not been characterized. We investigated the properties of period doubling in the rat cone flicker ERG elicited with full field, sinusoidal photic stimuli. Period doubling was observed when the temporal frequency of the stimulus was in the range of 20-30 Hz. The F/2 component of the Fourier spectrum of the ERG was more pronounced than its odd harmonics. The magnitude of the cycle-to-cycle variation in amplitude differed depending on whether measurements were based on peak-to-trough or trough-to-peak amplitudes, owing to the relative phase relationship between F/2 and F as a function of stimulus frequency. The frequency-response characteristics of period doubling varied with stimulus contrast, such that reducing the contrast shifted the peak F/2 amplitude to a lower stimulus frequency. Period doubling was evident in rat eyes in which PDA was administered intravitreally, indicating that the phenomenon can occur independently of OFF pathway activity in the rat retina. The period doubling properties we observed in the flicker ERG response of the rat cone system provide constraints on the nature of the nonlinear feedback mechanism presumed to underlie the period doubling phenomenon.
Authors:
Manthan R Shah; Kenneth R Alexander; Harris Ripps; Haohua Qian
Related Documents :
1464965 - Photopic electroretinogram b-wave implicit time in monkey eye.
19921295 - Spatial distributions of on- and off-responses determined with the multifocal erg.
21749915 - Fragile x protein expression is linked to visual functions in healthy male volunteers.
10549645 - Rod multifocal electroretinograms in mice.
20118305 - Echolocation call production during aerial and terrestrial locomotion by new zealand's ...
371345 - Variations of matrix electrondensity in brain mitochondria.
Publication Detail:
Type:  Journal Article; Research Support, N.I.H., Extramural; Research Support, Non-U.S. Gov't     Date:  2009-10-17
Journal Detail:
Title:  Experimental eye research     Volume:  90     ISSN:  1096-0007     ISO Abbreviation:  Exp. Eye Res.     Publication Date:  2010 Feb 
Date Detail:
Created Date:  2010-02-15     Completed Date:  2010-03-03     Revised Date:  2011-07-22    
Medline Journal Info:
Nlm Unique ID:  0370707     Medline TA:  Exp Eye Res     Country:  England    
Other Details:
Languages:  eng     Pagination:  196-202     Citation Subset:  IM    
Copyright Information:
Copyright 2009 Elsevier Ltd. All rights reserved.
Affiliation:
Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL 60612, USA.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Animals
Electroretinography*
Excitatory Amino Acid Antagonists / administration & dosage
Female
Injections
Male
Photic Stimulation
Pipecolic Acids / administration & dosage
Rats
Rats, Sprague-Dawley
Retinal Cone Photoreceptor Cells / physiology*
Retinal Ganglion Cells / drug effects,  physiology
Visual Pathways / physiology*
Vitreous Body
Grant Support
ID/Acronym/Agency:
EY01792/EY/NEI NIH HHS; EY08301/EY/NEI NIH HHS; P30 EY001792-309004/EY/NEI NIH HHS; R01 EY008301-19/EY/NEI NIH HHS
Chemical
Reg. No./Substance:
0/Excitatory Amino Acid Antagonists; 0/Pipecolic Acids; 46026-75-9/2,3-piperidinedicarboxylic acid
Comments/Corrections

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  A Validation Study of a New Molecular Diagnostic Assay: The Dartmouth-Hitchcock Medical Center Exper...
Next Document:  In sickness and in health: Corneal epithelial stem cell biology, pathology and therapy.