Interactions leading to horizontal cell responses in the turtle retina

Fuortes, M. G. F.; Simon, E. J.

doi:10.1113/jphysiol.1974.sp010606

Cited by 213 publications

(167 citation statements)

References 17 publications

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“…Linear inputs from each local region of the receptive field are simply added together to produce the overall response. This conclusion is based on the fact that luminosity horizontal cells in the turtle retina receive their major input from red-sensitive (630 nm) cones (12)(13)(14)(15)(16). We verified this fact during our experiments.…”

Section: Resultssupporting

confidence: 73%

Linear information processing in the retina: a study of horizontal cell responses.

Tranchina¹,

Gordon²,

Shapley³

et al. 1981

Proc. Natl. Acad. Sci. U.S.A.

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A basic question about visual perception is whether the retina produces a faithful or a distorted neural representation of the visual image. It is now well known that in some retinal pathways there are significant nonlinear transductions which distort the neural image. The next natural question is, What are the locations of the nonlinear stages within the retinal network? We report here on an investigation of linearity and nonlinearity ofresponses ofhorizontal cells in the turtle retina as an assay of the degree of nonlinearity in the outer plexiform layer of the retina. The visual stimuli were sinusoidal gratings; these patterns were modulated by contrast reversal with a sinusoidal time course. The conclusion from our experiments is that the turtle's horizontal cell responses show evidence only oflinear spatial summation even at moderately high contrasts on moderately high background levels. Our work thus indicates that there is no significant distortion of the visual image by the photoreceptors or by the neural summation of photoreceptor signals by horizontal cells under normal physiological conditions. These results are consistent with the view that the major nonlinearities ofthe retina are proximal to the outer plexiform layer.Horizontal cells in several fish retinas have been reported to be nearly linear in their response to diffuse illumination (1-3). A model based on the concept that the network of electrically coupled horizontal cells behaves as a single flat cell with passive spread of current injected at the synapses works well for horizontal cells ofcatfish (4, 5) and turtles (6). When the membrane conductance changes caused by the light stimulus are not too large, this model implies linear spatial summation. Horizontal cells in the cat respond to sinusoidal modulation of the luminance of spots with significant harmonic distortion only when relatively high modulation depths are used at frequencies below 2-3 Hz (7).We report here that luminosity horizontal cells (which hyperpolarize to all wavelengths of light) in the turtle and their presynaptic receptors act as linear tranducers in response to diffuse illumination and also in response to spatial patterns which test properties of spatial summation. METHODSIntracellular recordings were obtained from horizontal cells in isolated eye-cup preparations ofPseudemys scripta elegans (redeared turtle) and Chelydra serpentina (common snapping turtle) which gave similar results. The eye-cups were maintained in a moist oxygenated chamber at 16-20'C. Fine-tipped microelectrodes filled with 4 M potassium acetate (resistance, 100-300 MI) gave satisfactory results. The visual stimulus was a raster type display produced on a cathode ray tube oscilloscope screen (Tektronix 5103N, P31 phosphor, which has its spectral peak at 525 nm) by a special-purpose microcomputer (8) which also signal-averaged the response. A monochromator was used to test the spectral sensitivity of the neurons. The stimuli in these experiments were like those used in the past for studying...

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Section: Resultssupporting

confidence: 73%

Linear information processing in the retina: a study of horizontal cell responses.

Tranchina¹,

Gordon²,

Shapley³

et al. 1981

Proc. Natl. Acad. Sci. U.S.A.

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“…The "linear range responses" reported in earlier studies were produced by flashes given in the dark, except for those in the reports by Normann and his co-workers (Normann and Anderton, 1983;Daly and Normann, 1985), and the peak response times of these linear range responses were >_ 100 ms, which corresponds to the kernels obtained at -3 log mean irradiance in this article. The kernels with peak response times of 50 ms predicted actual responses with MSEs of <10% and the peak-to-peak excursion of the white-noise-evoked response was >5 mV, whereas the linear range responses obtained by the flash method were <1 mV in amplitude (Baylor and Hodgkin, 1973 ;Fuortes and Simon, 1974;Normann and Anderton, 1983). The linear responses we show here are therefore for a large range of amplitude excursion as well as for a much larger range of mean and modulation irradiance .…”

Section: Discussionmentioning

confidence: 68%

Dynamics of turtle cones.

Naka¹,

Itoh²,

Chappell³

1987

The Journal of General Physiology

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The response dynamics of turtle photoreceptors (cones) were studied by the cross-correlation method using a white-noise-modulated light stimulus . Incremental responses were characterized by the kernels. Whitenoise-evoked responses with a peak-to-peak excursion of >5 mV were linear, with mean square errors of^-8%, a degree of linearity comparable to the horizontal cell responses. Both a spot (0 .17 mm diam) and a large field of light produced almost identical kernels. The amplitudes of receptor kernels obtained at various mean irradiances fitted approximately the Weber-Fechner relationship and the mean levels controlled both the amplitude and the response dynamics ; kernels were slow and monophasic at low mean irradiance and were fast and biphasic at high mean irradiance . This is a parametric change and is a piecewise linearization. Horizontal cell kernels evoked by the small spot of light were monophasic and slower than the receptor kernels produced by the same stimulus . Larger spots of light or a steady annular illumination transformed the slow horizontal cell kernel into a fast kernel similar to those of the receptors. The slowing down of the kernel waveform was modeled by a simple low-pass circuit and the presumed feedback from horizontal cells onto cones did not appear to play a major role .

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“…The mechanisms responsible for the observed interactions between red and green may involve the spectrally antagonistic responses apparent in horizontal cells in the turtle (Fuortes, Schwartz & Simon 1973;Fuortes & Simon, 1974). Another possible site for chromatic interactions is suggested by the close association of the red-and green-sensitive members of the double cones which are present in the turtle (Richter & Simon, 1974;Baylor & Fettiplace, 1975) and in many other vertebrate species (Walls, 1942).…”

Section: Sensitizable Colour Cellsmentioning

confidence: 99%

Light responses of ganglion cells in the retina of the turtle

Bowling¹

1980

The Journal of Physiology

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SUMMARY1. Recordings were made from single axons of 218 ganglion cells in the optic nerve of the turtle, Pseudemys scripta elegans. Responses to light stimuli were used to classify 182 of the cells into four functional groups.2. Movement-sensitive cells (113 units) responded best to moving stimuli independent of the stimulus colour or direction of motion. Their receptive fields were organized into antagonistic centres and surrounds with the same spectral sensitivity. Based on their patterns of response they were of three types: ON-centre, OFF-centre, and ON-OFF.3. Directionally selective cells (sixty-five units) responded best to stimuli that moved in one preferred direction and not to stimuli that moved in the opposite direction. Their receptive fields had antagonistic centres and surrounds with the same spectral sensitivity. An area of silent inhibition could be shown on one side of the receptive fields. The preferred directions appeared to fall into three groups separated by about 120 degrees. Response patterns were of two types; OFF-centre and ON-OFF.4. Sensitizable colour cells (two units) had centre-surround organization with red-green opponent responses from both the centre and the surround (double opponent cells). In addition, the sensitivity to either of the opponent colours was effectively turned on or off by a steady background of the other opponent colour.5. Orientation cells (two units) responded best to moving bars of specific orientations in the visual field. Their receptive fields consisted of adjacent mutually antagonistic areas with linear boundaries. 6. Under photopic conditions all of the ganglion cells were most sensitive to light near 630 nm wave-length, the spectral maximum of the red-sensitive single cones in the turtle retina. About 75 % of the cells had a secondary spectral peak near 560 nm, the spectral maximum of the green-sensitive single cones. Three cells had unusually broad sensitivity extending into the blue portion of the spectrum. Over half of the cells received additional input from rods as evidenced by a shift in spectral sensitivity and increases in latencies and receptive field sizes with dark-adaptation.7. Measurements of the absolute sensitivity of the ganglion cells showed that a

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Interactions leading to horizontal cell responses in the turtle retina

Cited by 213 publications

References 17 publications

Linear information processing in the retina: a study of horizontal cell responses.

Linear information processing in the retina: a study of horizontal cell responses.

Dynamics of turtle cones.

Light responses of ganglion cells in the retina of the turtle

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