Simulations of X and Y retinal ganglion cell behavior with a nonlinear push-pull model of spatiotemporal retinal processing

Gaudiano, Paolo

doi:10.1016/0042-6989(94)90131-7

Cited by 28 publications

(37 citation statements)

References 43 publications

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“…For the element 'c' of either PR, BC, on-AC, off-AC or wf-AC, W ck is set to zero for every 'k' (cf. Gaudiano 1994;Thiel et al 2006).Parameter values in the equation were calibrated so that the temporal response dynamics of every neuronal element was reproduced in accordance with previous studies. Spatial parameters of the model (e.g., wiring and W ck ) are adjusted to qualitatively meet the spatial profile of ganglion cell responses given in the previous paper (Olveczky et al 2003).…”

Section: Spatio-temporal Modelmentioning

confidence: 97%

“…1) which was modified from pushpull shunting models of retinal neurons (Gaudiano 1994;Thiel et al 2006). Here, t c (t) stands for the membrane potential of the neuronal element of interest (the element 'c'); A represents the rate of passive decay toward the resting potential in the dark; B and D are the saturation levels for the excitatory inputs, e(t) and inhibitory inputs, i(t), respectively; t k (t) is the membrane potential of the neuronal element 'k' which makes lateral connections via the gap junction (HC-to-HC) or the chemical synapse (wf-AC-to-GC) with the element 'c'; W ck determines the efficiency of the lateral connections from the element 'k' to 'c' and its value is given by a function of the distance between 'k' and 'c'.…”

Section: Spatio-temporal Modelmentioning

confidence: 99%

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A retinal circuit model accounting for wide-field amacrine cells

2008

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In previous experimental studies on the visual processing in vertebrates, higher-order visual functions such as the object segregation from background were found even in the retinal stage. Previously, the ''linear-nonlinear'' (LN) cascade models have been applied to the retinal circuit, and succeeded to describe the input-output dynamics for certain parts of the circuit, e.g., the receptive field of the outer retinal neurons. And recently, some abstract models composed of LN cascades as the circuit elements could explain the higher-order retinal functions. However, in such a model, each class of retinal neurons is mostly omitted and thus, how those neurons play roles in the visual computations cannot be explored. Here, we present a spatio-temporal computational model of the vertebrate retina, based on the response function for each class of retinal neurons and on the anatomical inter-cellular connections. This model was capable of not only reproducing the spatio-temporal filtering properties of the outer retinal neurons, but also realizing the object segregation mechanism in the inner retinal circuit involving the ''widefield'' amacrine cells. Moreover, the first-order Wiener kernels calculated for the neurons in our model showed a reasonable fit to the kernels previously measured in the real retinal neuron in situ.

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Section: Spatio-temporal Modelmentioning

confidence: 97%

Section: Spatio-temporal Modelmentioning

confidence: 99%

A retinal circuit model accounting for wide-field amacrine cells

2008

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“…A progressive (i.e., hierarchical) complication of the model, e.g., by collecting the recurrent loop activity on higher layers, would account for the observed variability in the spatiotemporal responses of cortical simple cells, without compromising the modus operandi of the basic architectural core. Further improvements in the model should consider a number of other phenomena that might contribute to direction selectivity, in particular, the eect of a combination of lagged and nonlagged geniculate inputs (Mastronarde 1987;Saul and Humphrey 1990;Wimbauer et al 1994Wimbauer et al , 1997, expansive nonlinearities (Emerson 1997;Heeger 1993), and ON-OFF interactions (Ferster 1988;Gaudiano 1994). We plan to investigate these topics in future studies.…”

Section: Discussionmentioning

confidence: 99%

An architectural hypothesis for direction selectivity in the visual cortex: the role of spatially asymmetric intracortical inhibition

Sabatini

Solari

1999

Biological Cybernetics

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Abstract. Within a linear ®eld approach, an architectural model for simple cell direction selectivity in the visual cortex is proposed. The origin of direction selectivity is related to recurrent intracortical interactions with a spatially asymmetric character along the axis of stimulus motion. No explicit asymmetric temporal mechanisms are introduced or adopted. The analytical investigation of network behavior, carried out under the assumption of a linear superposition of geniculate and intracortical contributions, shows that motion sensitivity of the resulting receptive ®elds emerges as a dynamic property of the cortical network without any feed-forward direction selectivity bias. A detailed analysis of the eects of the architectural characteristics of the cortical network on directionality and velocityresponse curves was conducted by systematically varying the model's parameters. IntroductionRecent theoretical and neurophysiological studies (DeAngelis et al. 1993a,b;Hamilton et al. 1989;McLean et al. 1994; Reid et al. 1991;Tolhurst and Dean 1991) pointed out that the origin of direction selectivity can be related to the linear space-time receptive ®eld structure of simple cells. A large class of simple cells shows a very speci®c space-time behavior in which the spatial phase of the receptive ®eld changes gradually as a function of time. This results in receptive ®eld pro®les that tilt along an oblique axis in the space-time domain (i.e., they are space-time inseparable). Accurate estimates of the velocity components to which the cell is selective (the preferred speed of motion) can be derived by measuring the slope of oriented receptive ®eld subregions in the space-time domain. Since lateral geniculate nucleus (LGN) cells do not exhibit tilted subregions, the origin of space-time inseparability must take place within the striate cortex. In general, the construction of inseparable simple-cell receptive ®elds implies a position-dependent alteration of the temporal response characteristics of the aerent inputs, presumably associated with cortical circuits characterized by asymmetric architectural schemes in space and/or time (for a review, see Koch and Hildreth 1987). Several models have been proposed. Some postulate the combination of spatially oset geniculate receptive ®elds with dierent temporal dynamics (Mastronarde 1987;Saul and Humphrey 1990;Wimbauer et al. 1994Wimbauer et al. , 1997. Others assume intracortical interactions among separable simple-cell receptive ®elds, possibly mediated by cortical interneurons (Ganz 1984;Ru et al. 1987;Sillito 1977;Somers et al. 1995). Most models, however, do not consider explicit recurrent asymmetric intracortical processes, and furthermore, a clear distinction between the roles of purely spatial and purely temporal mechanisms has not yet been made.In this paper, we point out that a purely spatial asymmetry is sucient to generate directional selectivity when spatially asymmetric contributions arise through recurrent intracortical inhibitory circuits. Therefore, the spac...

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“…This paper reports some experimental results that test a prediction generated by the push-pull model of X and Y ganglion cells (Gaudiano 1994). The details of the pushpull model, which were originally published in this journal (Gaudiano 1992a(Gaudiano , 1992b, have been the subject of some debate (e.g., Freed and Nelson 1994).…”

Section: Introductionmentioning

confidence: 96%

“…Gaudiano (1992aGaudiano ( , 1992bGaudiano ( , 1994 has suggested that the dominant characteristics of both X and Y cells can be simulated with a single model simply by changing receptive ®eld pro®les to match those of the anatomical counterparts of X and Y cells. He also proposed that a signi®cant component of the spatial nonlinearities observed in Y (and sometimes X) cells can result from photoreceptor nonlinearities coupled with push-pull bipolar connections.…”

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confidence: 99%

Spatial asymmetries in cat retinal ganglion cell responses

Gaudiano

Przybyszewski

Wezel

et al. 1998

Biological Cybernetics

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Enroth-Cugell and Robson (1966) first proposed a classification of retinal ganglion cells into X cells, which exhibit approximate linear spatial summation and largely sustained responses, and Y cells, which exhibit nonlinearities and transient responses. Gaudiano (1992a, 1992b, 1994) has suggested that the dominant characteristics of both X and Y cells can be simulated with a single model simply by changing receptive field profiles to match those of the anatomical counterparts of X and Y cells. He also proposed that a significant component of the spatial nonlinearities observed in Y (and sometimes X) cells can result from photoreceptor nonlinearities coupled with push-pull bipolar connections. Specifically, an asymmetry was predicted in the ganglion cell response to rectangular gratings presented at different locations in the receptive field under two conditions: introduction/withdrawal (on-off) or contrast reversal. When measuring the response to these patterns as a function of spatial phase, the standard difference-of-Gaussians model predicts symmetrical responses about the receptive field center, while the push-pull model predicts slight but significant asymmetry in the on-off case only. To test this hypothesis, we have recorded ganglion cell responses from the optic tract fibers of anesthetized cat. The mean and standard deviations of responses to on-off and contrast-reversed patterns were compared. We found that all but one of the cells that yielded statistically significant data confirmed the hypothesis. These results largely support the theoretical prediction.

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Simulations of X and Y retinal ganglion cell behavior with a nonlinear push-pull model of spatiotemporal retinal processing

Cited by 28 publications

References 43 publications

A retinal circuit model accounting for wide-field amacrine cells

A retinal circuit model accounting for wide-field amacrine cells

An architectural hypothesis for direction selectivity in the visual cortex: the role of spatially asymmetric intracortical inhibition

Spatial asymmetries in cat retinal ganglion cell responses

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