Recovery of Retinal Function From Suppression Caused by Flashes of Light

Elenius, Valter

doi:10.1001/archopht.1967.00980030299007

Cited by 13 publications

(11 citation statements)

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“…To err on the side of caution we adopted an interval of at least 30 s for experiments done in the absence of a background, and at least 20 s for those done in the presence of a background. Our second conclusion is that following a flash of this intensity there exists an interval, from about 0.5 s to at least 1 s (or even 3 s in subject TDL), during which the cone system is fully recovered, yet the rods remain fully saturated (see Elenius, 1967Elenius, , 1969Birch et al 1995;Hood et al 1996). Accordingly, in all subsequent experiments, we determined the rod-isolated response by presenting stimuli during this interval of transient rod saturation.…”

Section: Recovery From Probe Flash: Choice Of Stimulus Repetition Intmentioning

confidence: 84%

“…Dodt, 1952;Mahneke, 1957;Burian & Spivey, 1959;Elenius, 1967Elenius, , 1969Gjötterberg, 1974). In the 1960s, it became clear that the a-wave of the ERG reflected photoreceptor activity (Brown & Wiesel, 1961), though it was not until the 1990s that quantitative analysis of the a-wave provided a faithful measure of photoreceptor currents (see, for example, Hood & Birch, 1990.…”

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confidence: 99%

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Time course of the flash response of dark‐ and light‐adapted human rod photoreceptors derived from the electroretinogram

Friedburg

Thomas

Lamb

2001

The Journal of Physiology

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Double-flash techniques have been used for decades to monitor the recovery of the a-wave and b-wave of the electroretinogram (ERG) following a first flash (e.g. Dodt, 1952;Mahneke, 1957;Burian & Spivey, 1959;Elenius, 1967Elenius, , 1969Gjötterberg, 1974). In the 1960s, it became clear that the a-wave of the ERG reflected photoreceptor activity (Brown & Wiesel, 1961), though it was not until the 1990s that quantitative analysis of the a-wave provided a faithful measure of photoreceptor currents (see, for example, Hood & Birch, 1990. Even so, the a-wave itself only provides information about photoreceptor currents at the very earliest times after a flash, before the b-wave and other post-receptoral signals intrude.With the insight provided by recent knowledge, several groups have monitored photoreceptor responses at later times, by recording the a-wave elicited by what has become known as a 'paired-flash' stimulus, in which an arbitrary test flash is followed at a range of time intervals by an intense probe flash (in human: Birch et al. 1995;Pepperberg et al. 1996Pepperberg et al. , 1997Cideciyan et al. 1998; in mouse: Lyubarsky & Pugh, 1996;Goto et al. 1996;Hetling & Pepperberg, 1999; reviewed in Pepperberg et al. 2000). In this technique, the amplitude of the response to the intense probe flash (i.e. the maximal response that can be elicited) provides a measure of the remaining circulating current in the photoreceptors at a particular time after the test flash. Although the method is tedious, in requiring numerous repetitions with different intervals between test and probe flashes, it currently provides the only means for extracting the response from photoreceptors in the living eye, at more than about 10 ms after a flash. 1. The a-wave of the electroretinogram was recorded from human subjects with normal vision, using a corneal electrode and ganzfeld stimulation. We applied the paired-flash technique, in which an intense 'probe' flash was delivered at different times after a 'test' flash. The amplitude of the probe-flash response provided a measure of the circulating current remaining at the appropriate time after the test flash.2. We extended previous methods by measuring not at a fixed time, but at a range of times after the probe flash, and then calculating the ratio of the 'test-plus-probe' response to the 'probealone' response, as a function of time.3. Under dark-adapted conditions the rod response derived by the paired-flash technique (in response to a relatively dim test flash) peaked at ca 120 ms, with a fractional sensitivity at the peak of ca 0.1 Td _1 s _1 .4. As reported previously, background illumination reduced the maximal response, reflecting a reduction in rod circulating current. In addition, it shortened the time to peak (to ca 70 ms at an intensity of 170 Td), and reduced the flash sensitivity measured at the peak. The flash sensitivity declined approximately according to Weber's Law, with a 10-fold reduction occurring at an intensity of 100-200 Td. We could not reliably measure responses ...

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Section: Recovery From Probe Flash: Choice Of Stimulus Repetition Intmentioning

confidence: 84%

mentioning

confidence: 99%

Time course of the flash response of dark‐ and light‐adapted human rod photoreceptors derived from the electroretinogram

Friedburg

Thomas

Lamb

2001

The Journal of Physiology

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“…I n previously dark-adapted normal human eye, the ERG evoked by the first stimulus (of a pair of stimuli of high luminance) is followed by a period during which the second ERG can be related only to "photopic" retinal mechanisms (Elenius 1967). Regression lines calculated for the process of recovery of rod function from suppression indicate an exponential recovery both for the a-and b-wave as well as for the total amplitude of the ERG-response.…”

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confidence: 96%

On the Oscillatory Potentials of the Human Electroretinogram in Light and Dark Adaptation

Wachtmeister

1973

Acta Ophthalmologica

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The effect of adaptation to short flashes of light on the oscillatory potentials and the slow potentials (a-and b-wave) of the human ERG as well as the effect on adaptometric visual threshold in response to a series of three flashes were studied. The total energy and the dominant frequency of the oscillatory potentials in response to the third (stimulus) flash were calculated by a combined impulse response and Fourier analysis when the interval between the flashes changed and the intensity of the first two (conditioning) flashes varied. When recorded in response to flashes given at long intervals or conditioning flashes of low intensity the visual threshold recovered to the scotopic branch of the dark adaptation curve and the oscillatory potentials showed a low energy and high frequency (around 150 Hz). On adaptation to flashes at shorter intervals and more intense conditioning flashes [above the threshold for the appearance of the photopic b-wave in response to the second (conditioning) flash], resulting in the recovery of the visual threshold to the photopic branch of the dark adaptation curve, there was an increment of energy and the frequency changed to 105-110 Hz.The slow potentials (a-and b-wave) and the oscillations were differently affected by adaptation to light by previous flashes. The oscillatory potentials showed a 10-fold gain in energy, whereas the amplitudes of the slow potentials were slightly reduced (about 10 Oio). The oscillatory potentials were optimally recorded in the mesopic range

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“…The authors favoured an explanation of the observed phenomena based on the dependence of the ERG on photochemical processes, referring to Dowling & Wald (1958) who found a parallelism between the electroretinographic threshold and the rhodopsin content in the retinas of vitamin-A deficient rats. Elenius (1967) investigated the ERG of the totally colour-blind eye with the double-flash technique. In the dark adapted state the ERG of the first flash was followed by a "refractory period" lasting for several hundred msec.…”

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confidence: 99%

Double Flash Human Electroretinogram With Special Reference to the Oscillatory Potentials and the Early Phase of Dark Adaptation: A Normative Study

Gjötterberg

1974

Acta Ophthalmologica

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The ERGS of 20 healthy humans were studied with a double-flash technique. The interval range between flashes was 0.35-180 sec and enabled the study of photopic as well as scotopic responses. The behaviour of the a-and b-waves was compared with that of the oscillatory potentials (0.p.) during the early phase of dark adaption. The amplitude of the a-and b-waves was decreasing the shorter the interval between flashes, while the amplitude of the 0.p. was maximal at the 30 sec interval. The first oscillatory peak behaved differently from the others. The recovery of the ERG from suppression by flashes was calculated for the a-and b-waves and a linear regression line was obtained. The 0.p. behaved differently. Comparison with the dark adaptation curve suggested the recovery of the a-and b-wave to be linked to a photochemical process and the 0.p. to a neural process.

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Recovery of Retinal Function From Suppression Caused by Flashes of Light

Cited by 13 publications

References 3 publications

Time course of the flash response of dark‐ and light‐adapted human rod photoreceptors derived from the electroretinogram

Time course of the flash response of dark‐ and light‐adapted human rod photoreceptors derived from the electroretinogram

On the Oscillatory Potentials of the Human Electroretinogram in Light and Dark Adaptation

Double Flash Human Electroretinogram With Special Reference to the Oscillatory Potentials and the Early Phase of Dark Adaptation: A Normative Study

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