title: Effects of background and spatial pattern on incremental sensitivity of catfish horizontal cells.
abstract: Incremental sensitivity of cones and horizontal cells was examined in the retina of the channel catfish (Ictalurus punctatus). In horizontal cells, steady full-field background illumination made the spot-evoked dynamic response larger and faster. The "enhancement" of incremental sensitivity was maximal at background levels of 20-50 microW/cm2. Similar changes in response were obtained by enlarging the diameter of the test spot (to 4 mm) without background illumination. In cones, no such enhancement with background was observed and small (0.4 mm) and large (4.0 mm) spots produced similar responses. Similar enhancement by a steady background has been observed also in the proximal neurons of catfish retina.
mesh_terms: D000818:Animals; D005399:Fishes / Q000502:physiology*; D005556:Form Perception / Q000502:physiology*; D007395:Interneurons / Q000502:physiology*; D009474:Neurons / Q000502:physiology; D010364:Pattern Recognition, Visual / Q000502:physiology*; D010775:Photic Stimulation; D010786:Photoreceptor Cells / Q000502:physiology; D012160:Retina / Q000502:physiology*; D012684:Sensory Thresholds; D013997:Time Factors