Balanced interactions in ganglion-cell receptive fields.
Receptive fields of retinal ganglion cells in turtle have excitatory and inhibitory components that are balanced along the dimensions of wavelength, functional ON and OFF responses, and spatial assignments of center and surround. These components were analyzed by spectral light adaptations and by the glutamate agonist, 2-amino-4-phosphonobutyric acid (APB). Extracellular recordings to stationary and moving spots of light were used to map changes in receptive fields. ON spike counts minus OFF spike counts, derived from flashed stationary light spots, quantified functional shifts by calculating normalized mean response modulations. The data show that receptive fields are not static, but rather are dynamic arrangements which depend on linked, antagonistic balances among the three dimensions of wavelength, ON and OFF response functions, and center/surround areas.
Granda
A M
AM
Department of Biological Sciences, University of Delaware, Newark 19716, USA.
Dearworth
J R
JR
Subramaniam
B
B
D000200:Action Potentials / Q000502:physiology; D000613:Aminobutyrates / Q000494:pharmacology; D000818:Animals; D003623:Dark Adaptation; D004594:Electrophysiology; D018690:Excitatory Amino Acid Agonists / Q000494:pharmacology; D010775:Photic Stimulation; D012165:Retinal Ganglion Cells / Q000187:drug effects / Q000502:physiology*; D014426:Turtles / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*
D000613:Aminobutyrates; D018690:Excitatory Amino Acid Agonists; C012729:2-amino-4-phosphonobutyric acid