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Titolo:
SPATIAL ASYMMETRIES IN CAT RETINAL GANGLION-CELL RESPONSES
Autore:
GAUDIANO P; PRZYBYSZEWSKI AW; VANWEZEL RJA; VANDEGRIND WA;
Indirizzi:
BOSTON UNIV,DEPT COGNIT & NEURAL SYST,677 BEACON ST BOSTON MA 02215 UNIV UTRECHT,HELMHOLTZ INST NL-3584 CH UTRECHT NETHERLANDS UNIV UTRECHT,DEPT COMPARAT PHYSIOL NL-3584 CH UTRECHT NETHERLANDS
Titolo Testata:
Biological cybernetics
fascicolo: 2, volume: 79, anno: 1998,
pagine: 151 - 159
SICI:
0340-1200(1998)79:2<151:SAICRG>2.0.ZU;2-9
Fonte:
ISI
Lingua:
ENG
Soggetto:
ON-CENTER; MODEL; ADAPTATION; DYNAMICS; BIPOLAR; LIGHT;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Science Citation Index Expanded
Citazioni:
26
Recensione:
Indirizzi per estratti:
Citazione:
P. Gaudiano et al., "SPATIAL ASYMMETRIES IN CAT RETINAL GANGLION-CELL RESPONSES", Biological cybernetics, 79(2), 1998, pp. 151-159

Abstract

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 fromphotoreceptor 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 asa 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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Documento generato il 03/12/20 alle ore 06:09:19