Spatio-temporal receptive fields in carp retinal horizontal cells.
1. The dynamics of the receptive fields of retinal horizontal cells were examined by applying a spatio-temporal modulated light signal to the retina. 2. The spatio-temporal receptive fields of both cone- and rod-driven horizontal cells, estimated through cross-correlation between the modulated light signal and the cells' responses, showed their receptive fields (the space-dependent component) to be reduced in size with time. 3. In cone-driven horizontal cells, the reduction in receptive field size was initially small but then rapidly became prominent with time. The time to peak of the time-dependent component of spatio-temporal receptive fields did not depend on the distance from the centre. 4. Application of a small amount of Co2+, an agent blocking the cone-driven horizontal cells' feedback action on cones, or GABA, resulted in a reversal of the time-dependent shrinkage of receptive fields to time-dependent expansion. 5. In rod-driven horizontal cells, the receptive field shrinkage was slow. The time to peak of the time-dependent component decreased with the distance from the centre. 6. Image processing experiments examining the response pattern in the horizontal cell layer (neural image) to a moving square of light showed smudging of the neural image when the time-dependent receptive field expansion was present, while there was essentially no smudging under conditions of receptive field shrinkage.
Umino
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O
Department of Information Science, Toho University, Funabashi-shi, Chiba 274, Japan. umino@is.sci.toho-u.ac.jp
Ushio
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T
D000818:Animals; D002347:Carps; D005246:Feedback; D008027:Light; D008564:Membrane Potentials; D008954:Models, Biological; D011930:Reaction Time; D012160:Retina / Q000166:cytology / Q000502:physiology* / Q000528:radiation effects; D017949:Retinal Cone Photoreceptor Cells / Q000187:drug effects / Q000502:physiology* / Q000528:radiation effects; D017948:Retinal Rod Photoreceptor Cells / Q000187:drug effects / Q000502:physiology* / Q000528:radiation effects; D014785:Vision, Ocular / Q000502:physiology*; D005680:gamma-Aminobutyric Acid / Q000494:pharmacology
D005680:gamma-Aminobutyric Acid