Two distinct processes are evident in rat cone flicker ERG responses at low and high temporal frequencies

Qian, Haohua; Shah, Manthan; Alexander, Kenneth R.; Ripps, Harris

doi:10.1016/j.exer.2008.04.011

Cited by 16 publications

(36 citation statements)

References 20 publications

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“…For the response elicited by sine-wave modulated light stimuli, the amplitudes of the fundamental responses at each respective stimulus frequency are plotted. In agreement with our previous report (Qian et al, 2008), the amplitude of the fundamental response to sine-wave flicker exhibited a monotonic low-pass pattern.…”

Section: Discussionsupporting

confidence: 80%

“…In all flash luminosities tested, humps in high harmonic components were observed in pulse flicker ERG responses. It has been reported that, for sine-wave flicker ERG, responses elicited from rat eyes exhibit two distinct processes at low and high temporal frequencies (Qian et al, 2008). In particular, the contrast-response relation is linear when tested with a low-frequency (6 Hz) stimulus, but saturated in response to a high-frequency (20 Hz) stimulus.…”

Section: Effects Of Flash Intensity On Pulse Flicker Ergmentioning

confidence: 99%

“…Instrumentation and recording procedures have described in our previous publication (Qian et al, 2008). Light stimuli were delivered by multiple light-emitting diodes (LEDs) with a peak wavelength of 505 nm (Nichia NSPE590S, Tokushima, Japan) mounted in a small integrating sphere (Oriel 70500, Newport Corp., Stratford, CT) to provide a full-field stimulus.…”

Section: Erg Recording and Light Stimulationmentioning

confidence: 99%

“…Two kinds of light stimuli are commonly used for flicker ERG recordings: sinewave modulated light and a pulse light flickers. Sine-wave modulated light, due to its simplicity in spectrum component, is often used to characterize frequency-response relationship of ERG Burns et al, 1992;Kondo and Sieving, 2001;Krishna et al, 2002;Qian et al, 2008;Viswanathan et al, 2002). On the other hand, pulse light flicker can easily be implemented technically, and has long been applied for clinical use (Audo et al, 2008;Garry et al, 2010;Jacobs et al, 1996).…”

Section: Introductionmentioning

confidence: 99%

“…ERG elicited by a periodic stimulus (flicker ERG) is a useful tool to investigate temporal property of retinal circuitry, especially cone pathway in the retina (Alexander et al, 2005;Burns et al, 1992;Kondo and Sieving, 2001;Qian et al, 2010;Qian et al, 2008). Two kinds of light stimuli are commonly used for flicker ERG recordings: sinewave modulated light and a pulse light flickers.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Comparison of Rat Cone ERG Elicited by a Pulse Flicker and Sine-Wave Modulated Light Stimuli

Qian¹,

Shah²

2011

Electroretinograms

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Section: Discussionsupporting

confidence: 80%

Section: Effects Of Flash Intensity On Pulse Flicker Ergmentioning

confidence: 99%

Section: Erg Recording and Light Stimulationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Comparison of Rat Cone ERG Elicited by a Pulse Flicker and Sine-Wave Modulated Light Stimuli

Qian¹,

Shah²

2011

Electroretinograms

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Mice homozygous for c.451C>T mutation in Cln1 gene recapitulate INCL phenotype

Bouchelion

Zhang

et al. 2014

Ann Clin Transl Neurol

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ObjectiveNonsense mutations account for 5–70% of all genetic disorders. In the United States, nonsense mutations in the CLN1/PPT1 gene underlie >40% of the patients with infantile neuronal ceroid lipofuscinosis (INCL), a devastating neurodegenerative lysosomal storage disease. We sought to generate a reliable mouse model of INCL carrying the most common Ppt1 nonsense mutation (c.451C>T) found in the United States patient population to provide a platform for evaluating nonsense suppressors in vivo.MethodsWe knocked-in c.451C>T nonsense mutation in the Ppt1 gene in C57 embryonic stem (ES) cells using a targeting vector in which LoxP flanked the Neo cassette, which was removed from targeted ES cells by electroporating Cre. Two independently targeted ES clones were injected into blastocysts to generate syngenic C57 knock-in mice, obviating the necessity for extensive backcrossing.ResultsGeneration of Ppt1-KI mice was confirmed by DNA sequencing, which showed the presence of c.451C>T mutation in the Ppt1 gene. These mice are viable and fertile, although they developed spasticity (a “clasping” phenotype) at a median age of 6 months. Autofluorescent storage materials accumulated throughout the brain regions and in visceral organs. Electron microscopic analysis of the brain and the spleen showed granular osmiophilic deposits. Increased neuronal apoptosis was particularly evident in cerebral cortex and abnormal histopathological and electroretinographic (ERG) analyses attested striking retinal degeneration. Progressive deterioration of motor coordination and behavioral parameters continued until eventual death.InterpretationOur findings show that Ppt1-KI mice reliably recapitulate INCL phenotype providing a platform for testing the efficacy of existing and novel nonsense suppressors in vivo.

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Characteristics of period doubling in the rat cone flicker ERG

Shah

Alexander

Ripps

et al. 2010

Experimental Eye Research

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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 to 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.

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Two distinct processes are evident in rat cone flicker ERG responses at low and high temporal frequencies

Cited by 16 publications

References 20 publications

Comparison of Rat Cone ERG Elicited by a Pulse Flicker and Sine-Wave Modulated Light Stimuli

Comparison of Rat Cone ERG Elicited by a Pulse Flicker and Sine-Wave Modulated Light Stimuli

Mice homozygous for c.451C>T mutation in Cln1 gene recapitulate INCL phenotype

Characteristics of period doubling in the rat cone flicker ERG

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