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Journal ArticleDOI

Proximal negative response of frog retina.

01 May 1970-Journal of Neurophysiology (J Neurophysiol)-Vol. 33, Iss: 3, pp 405-420
About: This article is published in Journal of Neurophysiology.The article was published on 1970-05-01. It has received 93 citations till now. The article focuses on the topics: Electroretinography & Retina.
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Journal ArticleDOI
TL;DR: The available evidence indicates the pigment epithelium as the probable c-wave generator, but the functional signature of the ERG is yet to be established.
Abstract: THE EI,ECTROKETI~‘~'~GRAM (ERG) was first recorded by Holmgren in 1865 (ZO), and it has proved to be a useful tool for studying retinal function for almost a century. Despite extensive studies, however, the cellular origins of the ERG components proximal to the receptors remain to be established. Quite recently it has become possible to record intracellularly from the retinal cells with fine micropipettes (2, 22, 34, 39), and thus the precise origins of the ERG components can now be investigated more directly. Our views on the components of the ERG are based mainly on the classic studies of Granit (19, 20). He analyzed the waveforms of the ERG into three components: an initial negative wave (PIII), which lasts the duration of the stimulus; an early transient positive wave (PII); and a late transient positive wave (PI). Granit (19) named these components in order of their sensitivity to ether narcosis. These components interact to produce the a, b, and c waves, respectively, of the intact ERG (16). PI (the c-wave) appears to originate in the pigment epithelium. Noel1 has shown that sodium iodate selectively abolishes the cwave as it destroys the pigment epithelial cells (27, 28). Also, Brown and Diesel (10) have reported intracellular records obtained from pigment epithelial cells and these records show a c-wave of reversed (negative) polarity with respect to the extracellular c-wave. Although the available evidence indicates the pigment epithelium as the probable c-wave generator, < the functional sig-

637 citations


Cites background from "Proximal negative response of frog ..."

  • ...Using extracellular microelectrodes in the frog, Burkhardt has recently separated the extracellular amacrine response from the intraretinal b-wave (11, 12)....

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  • ...Both the Miiller cell and the b-wave show a dynamic range of about 5 log units; this range is much greater than the values reported for bipolars (lr/* log units) or amacrines (2 log units) (12, 39)....

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  • ...Also, the extracellular amacrine response behaves quite differently to various stimulus spot sizes, position, and intensity, as compared with the intraretinal b-wave (11, 12)....

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Journal ArticleDOI
TL;DR: The oscillatory potentials (OPs) are good indicators of neuronal adaptive mechanisms in the retina and are probably the only post-synaptic neuronal components that can be recorded in the ERG except when structured stimuli are used.

496 citations

Journal Article
TL;DR: Considering its broad distribution, its many cytoprotective attributes, and its functional significance in cell development, nutrition, and survival, taurine is undoubtedly one of the most essential substances in the body.
Abstract: Taurine is an organic osmolyte involved in cell volume regulation, and provides a substrate for the formation of bile salts. It plays a role in the modulation of intracellular free calcium concentration, and although it is one of the few amino acids not incorporated into proteins, taurine is one of the most abundant amino acids in the brain, retina, muscle tissue, and organs throughout the body. Taurine serves a wide variety of functions in the central nervous system, from development to cytoprotection, and taurine deficiency is associated with cardiomyopathy, renal dysfunction, developmental abnormalities, and severe damage to retinal neurons. All ocular tissues contain taurine, and quantitative analysis of ocular tissue extracts of the rat eye revealed that taurine was the most abundant amino acid in the retina, vitreous, lens, cornea, iris, and ciliary body. In the retina, taurine is critical for photoreceptor development and acts as a cytoprotectant against stress-related neuronal damage and other pathological conditions. Despite its many functional properties, however, the cellular and biochemical mechanisms mediating the actions of taurine are not fully known. Nevertheless, considering its broad distribution, its many cytoprotective attributes, and its functional significance in cell development, nutrition, and survival, taurine is undoubtedly one of the most essential substances in the body. Interestingly, taurine satisfies many of the criteria considered essential for inclusion in the inventory of neurotransmitters, but evidence of a taurine-specific receptor has yet to be identified in the vertebrate nervous system. In this report, we present a broad overview of the functional properties of taurine, some of the consequences of taurine deficiency, and the results of studies in animal models suggesting that taurine may play a therapeutic role in the management of epilepsy and diabetes.

484 citations


Cites background from "Proximal negative response of frog ..."

  • ...In their initial studies on the action of taurine on neuronal pathways in the rabbit retina, Cunningham and Miller [140] showed that taurine was able to separate the ‘On’ and ‘Off’ channels of the parallel pathways identified in recordings of the electroretinogram, the proximal negative response of amacrine cells [141], and the spontaneous activity of ganglion cells....

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Journal Article
TL;DR: This paper shall review some of this recent work on the synaptic contacts in the vertebrate retina and the electrical responses of the six principal types of retinal cells, and infer probable sites of interaction and major synaptic pathways that occur within the vertebrates retina.
Abstract: JL he vertebrate retina is a portion of nervous tissue that has long been of interest both to investigators of brain function and of the visual process. It is one of the most accessible parts of the central nervous system; it can be easily and precisely stimulated with patterns of light; and its output, via the optic nerve, can be readily monitored. Recent studies employing electron microscopy and intracellular recording techniques have described the synaptic contacts in the vertebrate retina and the electrical responses of the six principal types of retinal cells. This new information, coupled with the knowledge of the retinal cells derived from light microscopy, permits us to infer probable sites of interaction and major synaptic pathways that occur within the vertebrate retina. In this paper I shall review some of this recent

302 citations

Journal ArticleDOI
TL;DR: The effect of these drugs for every type of ganglion cell with complex receptive field properties was to make the receptive field more simple, and the orientation selective cells, large field cells, 'on' direction selective cells and uniformity detectors seem to be centre surround cells with special properties that are abolished by these drugs.
Abstract: 1. The effects of picrotoxin and strychnine were tested on the receptive fields of direction sensitive cells, orientation sensitive cells, local edge detectors, uniformity detectors and large field units in the rabbit retina. 2. Picrotoxin eliminated the direction specificity and size specificity of 'on-off' and 'on' directionally sensitive cells for both black and white objects. Picrotoxin also made 'on' directionally sensitive cells responsive to faster velocities. 3. Picrotoxin eliminated the orientation specificity of orientation sensitive cells, and changed the bar-flank arrangement of the receptive field into a centre surround arrangement. Thus, the orientation specificity is due to inhibitory rather than excitatory mechanisms. 4. Picrotoxin altered the speed sensitivity of large field units so that they responded to slow speeds as well as fast ones, like centre surround Y cells. 5. Strychnine abolished the size specificity of local edge detectors and changed their speed specificity so that they responded to faster speeds. 6. Picrotoxin changed a uniformity detector into a sustained on centre cell. 7. Strychnine did not effect the direction specificity of directionally sensitive cells, the orientation specificity of orientation sensitive cells, or the speed specificity of large field units. Picrotoxin did not affect the size specificity of local edge detectors. 8. Picrotoxin and strychnine usually had opposing effects on the transient responses of these units to spots and annuli. In general picrotoxin prolonged and enhanced these responses at both on and off, and strychnine shortened them. 9. The effect of these drugs for every type of ganglion cell with complex receptive field properties was to make the receptive field more simple. The orientation selective cells, large field cells, 'on' direction selective cells and uniformity detectors seem to be centre surround cells with special properties that are abolished by these drugs. The 'on-off' direction selective cells and local edge detectors still on-off receptive fields, but in each case one of the drugs abolished the feature that was the basis for the cell's name.

290 citations