title: Stimulus Contrast and Retinogeniculate Signal Processing.
abstract: Neuronal signals conveying luminance contrast play a key role in nearly all aspects of perception, including depth perception, texture discrimination, and motion perception. Although much is known about the retinal mechanisms responsible for encoding contrast information, relatively little is known about the relationship between stimulus contrast and the processing of neuronal signals between visual structures. Here, we describe simultaneous recordings from monosynaptically connected retinal ganglion cells and lateral geniculate nucleus (LGN) neurons in the cat to determine how stimulus contrast affects the communication of visual signals between the two structures. Our results indicate that: (1) LGN neurons typically reach their half-maximal response at lower contrasts than their individual retinal inputs and (2) LGN neurons exhibit greater contrast-dependent phase advance (CDPA) than their retinal inputs. Further analyses suggests that increased sensitivity relies on spatial convergence of multiple retinal inputs, while increased CDPA is achieved, in part, on temporal summation of arriving signals.
authors.affiliation: Center for Neuroscience, University of CaliforniaDavis, Davis, CA, USA; Institute for Ophthalmology and Center for Integrative Neuroscience, University of TübingenTübingen, Germany.
authors.forename: Daniel L
authors.initials: DL
authors.lastname: Rathbun
authors.affiliation: Center for Neuroscience, University of CaliforniaDavis, Davis, CA, USA; Department of Neurobiology, Physiology, and Behavior, University of CaliforniaDavis, Davis, CA, USA.
authors.forename: Henry J
authors.initials: HJ
authors.lastname: Alitto
authors.affiliation: Center for Neuroscience, University of CaliforniaDavis, Davis, CA, USA; Department of Neurobiology, Physiology, and Behavior, University of CaliforniaDavis, Davis, CA, USA.
authors.forename: David K
authors.initials: DK
authors.lastname: Warland
authors.affiliation: Center for Neuroscience, University of CaliforniaDavis, Davis, CA, USA; Department of Neurobiology, Physiology, and Behavior, University of CaliforniaDavis, Davis, CA, USA.
authors.forename: W Martin
authors.initials: WM
authors.lastname: Usrey
mesh_terms: D000200:Action Potentials / Q000502:physiology; D000818:Animals; D001931:Brain Mapping; D002415:Cats; D015350:Contrast Sensitivity / Q000502:physiology*; D004562:Electrocardiography; D004569:Electroencephalography; D005260:Female; D005829:Geniculate Bodies / Q000166:cytology / Q000502:physiology*; D008297:Male; D008954:Models, Biological; D010775:Photic Stimulation; D012160:Retina / Q000166:cytology / Q000502:physiology*; D011984:Sensory Receptor Cells / Q000502:physiology*; D014795:Visual Pathways / Q000502:physiology*
keywords: LGN; coding; retina; thalamus; vision