Rod-only electroretinograms (ERGs) were recorded from 6-week and 4-month-old normal human infants. The leading edge of the rod a-wave was fitted with a model of the activation phase of phototransduction to provide estimates of S (a sensitivity parameter) and RmP3 (the maximum saturated photoreceptor response) at each of the investigated ages. Both S and RmP3 increased over the first postnatal m...

PURPOSE To test the hypothesis that electroretinograms (ERGs) reflect luminance activity when measured at high temporal frequencies and chromatic activity when measured near 12 Hz. METHODS The authors measured the responses to stimuli in which the output of red and green light-emitting diodes was modulated in counterphase at different ratios, varying the luminance content in the stimulus whil...

To investigate the effects of quinine on the electroretinograms (ERGs) of children with cerebral malaria (CM), we recruited subjects during a single malaria season in Blantyre, Malawi. Seventy ERG investigations were performed, on 34 children with CM. Time recorded from completion of the most recent quinine infusion was termed "quinine elapsed time" (QET). In a subgroup of 16 children, whole-bl...

Blue cone monochromacy (BCM) is an X-linked condition in which long- (L) and middle- (M) wavelength-sensitive cone function is absent. Due to the X-linked nature of the condition, female carriers are spared from a full manifestation of the associated defects but can show visual symptoms, including abnormal cone electroretinograms. Here we imaged the cone mosaic in four females carrying an L/M a...

We mapped a new X-linked recessive atrophic macular degeneration locus to Xp21.1-p11.4 and show allelic involvement of the gene RPGR, which normally causes severe peripheral retinal degeneration leading to global blindness. Ten affected males whom we examined had primarily macular atrophy causing progressive loss of visual acuity with minimal peripheral visual impairment. One additional male sh...

Retinal bipolar cells are essential to the transmission of light information. Although bipolar cell dysfunction can result in blindness, little is known about the factors required for bipolar cell development and functional maturation. The basic helix-loop-helix (bHLH) transcription factor Bhlhb4 was found to be expressed in rod bipolar cells (RB). Electroretinograms (ERGs) in the adult Bhlhb4 ...

Electroretinograms (ERGs) were elicited by hemicircular (half-disc) stimuli to the upper, lower, temporal and nasal maculas of 26 normal subjects, and the amplitudes and implicit times of the ERGs from opposing macular regions were compared. The amplitudes of a-wave, b-wave and oscillatory potentials (OPs) were significantly larger in the upper macular region than in the lower macular region (P...

1. Marg, E., Freeman, D., Peltzman, P., and Foldstein, P. J.: Visual acuity development in human infants: evoked potential measurement, INVEST. OPHTHALMOL. 15:150, 1976. 2. Sokol, S.: Visually evoked potentials: theory, techniques and clinical applications, Surv. Ophthalmol. 21:18, 1977. 3. Horowitz, J. A., Dawson, W. W., and Rubin, M. L.: Transscleral stimulator for the visual-evoked response,...

One eye of rd12 mice received a sub-retinal injection of a vector carrying normal human RPE65 cDNA at post-natal day 18, and at 6- and 13-months of age. Electroretinograms (ERGs) and visual-evoked potentials (VEPs) were recorded to luminance, and to spatially and temporally modulated stimuli to assess the consequences of delayed treatment on visual pathway function. Early treatment resulted in ...

Changes in sensitivity of the photoreceptor cells of the anterior median eye of the jumping spider Menemerus confusus Boes. et Str. have been studied by recording electroretinograms (ERGs) and receptor potentials. The amplitudes of the responses (ERGs and receptor potentials) increase during repetitive stimulation, with a maximum increase at 3-5 s intervals. The sensitivity of the photoreceptor...