Neurobiology of perfused mammalian eyes

Niemeyer, G.

doi:10.1016/0165-0270(81)90022-4

Cited by 46 publications

(16 citation statements)

References 43 publications

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“…The optic nerve response recorded in vitro in relation to the STR Finally I shall discuss the summed action potential of the mammalian optic nerve as recorded from the isolated arterially perfused feline eye in vitro [24][25][26][27]. The in vitro perfused isolated mammalian eye preparation affords the opportunity to monitor the summed ganglion cell activity as the output of retinal excitation via a simple Ag-AgCl suction electrode at the severed end of the optic nerve and a surface electrode (Figure 4a).…”

Section: Proximal Negative Response (Pnr)mentioning

confidence: 99%

ERG Components of Negative Polarity from the Inner Retina and the Optic Nerve Response

Niemeyer

2005

Doc Ophthalmol

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ERG components of negative polarity in the light-adapted and in the dark-adapted inner retina are reviewed from a clinical perspective and include consideration of experimental research. Field potentials are inherently complex including summating contributions from specialized neurons as well as from glial elements. This property applies to the PERG, PhNR and to the STR. Experimental research can contribute to identifying the sites/cells of origins i.e. by determining depth profiles and by pharmacological manipulation. Intraretinal microelectrode-studies and pharmacological dissection of light-evoked responses have elucidated the origin of field potentials from the retinal pigment epithelium to the retinal ganglion cells. Thresholds for dark-adapted response components have been compared. Attenuation of the STR by anesthesia was found in cats in vivo when compared to threshold intensities used in isolated eye preparations in vitro, suggestive of depression of inner retinal activity by anesthetics. Evidence has been presented for antidromically elicited retinal responses of negative polarity that resemble the STR and summate with the light-evoked retinal response. This observation supports the notion that negative field potentials and components as recorded in the vitreous and at the cornea receive contributions from retinal ganglion cells. The weight of this contribution appears to vary among species, at least concerning the STR. The ocular negative reponses from the inner retina are compared to cortical excitatory mechanisms generating negativity in the baseline of the EEG.

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Section: Proximal Negative Response (Pnr)mentioning

confidence: 99%

ERG Components of Negative Polarity from the Inner Retina and the Optic Nerve Response

Niemeyer

2005

Doc Ophthalmol

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“…Tiiumer, 1976;Arden & Kelsey, 1962). Direct-coupled recording is more feasible in animals and large light peaks can be recorded from many species (Kikawada, 1968;Noell, 1953;Niemeyer, 1980;Steinberg & Niemeyer, 1981;Gouras & Carr, 1965a, b;Valeton & van Norren, 1981). However, the light peak has only been observed in the vertebrate classes Reptilia, Aves, and Mammalia (Kikawada, 1968), suggesting that it may be a relatively recent development in evolution.…”

Section: Introductionmentioning

confidence: 99%

Origin of the light peak: in vitro study of Gekko gekko

Griff

Steinberg

1982

The Journal of Physiology

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SUMMARY1. The light peak is a large, light-evoked increase in standing potential recorded in mammals, birds and reptiles. We have studied the cellular origin of the light peak in an in vitro preparation of neural retina-pigment epithelium (r.p.e)-choroid from the lizard, Gekko gekko. The tissue was mounted between two separate bathing solutions; the trans-tissue potential was recorded retinal-side positive; microelectrodes were introduced to measure the trans-epithelial potential (t.e.p.) and to record intracellularly from the r.p.e.2. A 10 min stimulus of diffuse white light evoked an increase in trans-tissue potential that reached maximum amplitude, the light peak, about 15 min after stimulus onset. Since the light peak is present in vitro, it must originate in either the neural retina or the r.p.e.3. A micro-electrode was positioned in the subretinal space and the trans-retinal potential and t.e.p. were measured simultaneously. A 10 min stimulus produced an increase in t.e.p. equal in magnitude and time course to the trans-tissue light peak; no potential was present across the retina. The light peak is therefore generated solely across the r.p.e.4. Intracellular r.p.e. recordings were made to determine whether the light peak was generated at the apical or basal membrane or across the paracellular shunt. A 10 min stimulus first caused a hyperpolarization of both membranes with a time course similar to the r.p.e. c-wave followed by a depolarization of both membranes with the time course of the light peak. We conclude that whereas the r.p.e. c-wave results from a hyperpolarization of the apical membrane, the light peak is generated by a depolarization of the basal membrane of the r.p.e. 5. Changes in tissue resistance, Rt, and the ratio of apical to basal membrane resistances, a, were monitored during the light peak by passing current across the tissue and measuring the appropriate current-induced voltages. Rt decreased and a increased with the time course of the light peak. Assuming that the paracellular shunt resistance is constant, we conclude that the light peak is accompanied by an increase in basal membrane conductance.6. This and the following paper present the first direct demonstration of an interaction between the neural retina and the basal membrane of the r.p.e. The light peak, initiated by absorption of light by photoreceptors, results in a depolarization and conductance increase of the basal membrane.

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“…The negative response following the b-wave increased and resulted in remarkable changes in configuration in the ERG. The ONR, which is very sensitive to pharmacological manipulations in the retina [7], showed marked configurational changes consisting of a depression of the late ON-component and decrease in OFF effects with a time course similar to changes in the ERG. Similar effects were observed for nylidrin.…”

Section: Resultsmentioning

confidence: 99%

“…After the ophthalmociliary artery was cannulated, the eye was perfused with the following oxygenated solution: 150ml 10 x medium 199 modified with Earle's salts and without NaHCO3 and glutamine, 30ml HEPES buffer, 2ml garamycin (40mg/ml), 5.1 ml 200mM L-glutamine, 600ml newborn bovine serum, and 1320ml distilled water. The perfusate was titrated to a pH of 7.51 at room temperature, filtered, and maintained at a temperature of 37 ~ Details of the experimental procedure have been published previously [5,6,7].…”

Section: Methodsmentioning

confidence: 99%

The effects of ?-adrenergic agonists on cone systems in the cat eye

1988

Self Cite

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The effects of the beta-adrenergic agonist nylidrin and the beta 2-adrenergic agonist clenbuterol on electroretinogram and optic nerve response were studied in the isolated and arterially perfused, light-adapted cat eye. Two cone mechanisms, short wavelength-sensitive and long wavelength-sensitive, were functionally separated by means of intense yellow adaptation. A reversible increase in b-wave amplitude in response to nylidrin or clenbuterol was observed for the cone systems. Both drugs also caused a reversible alteration in configuration of the optic nerve response, mainly a depression of the late components related in time to the changes in the electroretinogram. These observations suggest that beta-adrenergic mechanisms are involved in cone systems. The greater increase in b-wave amplitude on 558-nm stimulation and preliminary evidence for greater increase in sensitivity observed in the V-log I function compared with 439 nm further suggest that the short and long wavelength cone systems are affected differently by beta-adrenergic agonists.

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Neurobiology of perfused mammalian eyes

Cited by 46 publications

References 43 publications

ERG Components of Negative Polarity from the Inner Retina and the Optic Nerve Response

ERG Components of Negative Polarity from the Inner Retina and the Optic Nerve Response

Origin of the light peak: in vitro study of Gekko gekko

The effects of ?-adrenergic agonists on cone systems in the cat eye

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