Spatial organization of catfish retinal neurons. I. Single- and random-bar stimulation.
1. Receptive-field profiles of catfish (Ictalurus punctatus) retinal neurons were produced by a moving single bar or a moving random grating, which was swept across the cell's receptive field at a constant speed. 2. Bipolar cells form either an on- or an off-center biphasic field and are approximately linear in time and space. 3. Type-C or transient cells form predominantly monotonic receptive fields. We find two subclasses, one slow and the other fast transient cells. They can be identified functionally as well as morphologically. 4. Type-N or sustained cells form a biphasic receptive field, which is revealed by a bar of light. The monotonic field found by a spot or an annulus of light represents activity of the cell's field center. 5. There are two ganglion-cell types, small-field cells and large-field cells. It appears as if small-field cells copy signals in the bipolar cells and large-field cells, signals in the type-N cells. We suggest, however, that this observation represents the limitation imposed by our stimuli rather than an overall functional characteristic of catfish ganglion cells.
D000818:Animals; D004594:Electrophysiology; D005399:Fishes / Q000033:anatomy & histology*; D009474:Neurons / Q000166:cytology / Q000502:physiology; D012160:Retina / Q000033:anatomy & histology / Q000166:cytology* / Q000502:physiology; D014785:Vision, Ocular / Q000502:physiology*; D014794:Visual Fields