Frank Naarendorp

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Visual thresholds of mice for the detection of small, brief targets were measured with a novel behavioral methodology in the dark and in the presence of adapting lights spanning ∼8 log(10) units of intensity. To help dissect the contributions of rod and cone pathways, both wild-type mice and mice lacking rod (Gnat1(-/-)) or cone (Gnat2(cpfl3)) function were(More)
The goal of the present study was to relate the dark and light-adapted flash sensitivity of the scotopic threshold response (STR) and rod b-wave of the electroretinogram (ERG) to behaviorally measured rod increment threshold responses. Small amplitudes of the dark-adapted STR and b-wave, the latter after application of NMDA, were found to increase in(More)
We studied the off-response of the rat ERG evoked with long duration, mesopic stimuli during light and dark adaptation, and after intravitreal injection of aspartate and (+/-)-cis-piperidine-2,3-dicarboxylic acid (PDA). At stimulus offset, the dark-adapted ERG always showed a rapid negative deflection followed by a positive deflection after which the(More)
The influence of annular fields on sensitivity to sinusoidal flicker was assessed in the dark adapted parafoveal retina. Test stimuli were 2 degrees 20' in diameter; annuli had a 2 degrees 20' inner and 7 degrees 30' outer diameter. Rod flicker was studied with a "green" stimulus too dim to influence cones. Selective cone flicker was obtained using red and(More)
1. The influences of short-term visual adaptation of either rods or cones upon cone-mediated grating visibility were compared with their influences upon detection threshold in both the fovea and parafoveal retina. Short-term visual adaptation was induced by 20 deg diameter adapting fields (AFs) generally of 500 ms duration. The AF was either -0.5 log td in(More)
In the retina of rat, cones make up approximately 0.85% of the photoreceptor population: 93% of these cones contain a midwave-sensitive pigment, the rest expresses a short-wave-sensitive pigment (Szel & Rohlich, 1992). We used normal adult Long Evans rats to determine the spectral sensitivity of the cone-driven electroretinogram (ERG) b-wave and its(More)
The influence of rod light and dark adaptation upon cone mediated spatial acuity was studied in the near parafoveal retina of normal human observers. The luminance just necessary to detect squarewave test gratings of variable frequency provided an index of spatial acuity. Such thresholds were determined in the presence of background fields which were varied(More)
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