Red/green opponency in the rhesus macaque ERG spectral sensitivity is reduced by bicuculline.
Spectral-sensitivity curves were derived from the a-, b-, and d-waves of rhesus monkey ERGs after injection of bicuculline, strychnine, or no drug. Without drug injection, the a- and d-wave curves were well-fit by an additive model of weighted photoreceptor absorption spectra, while the b-wave curve requires inhibitory terms to produce an adequate fit. Bicuculline, but not strychnine, reduced the weight assigned to the inhibitory terms in a dose-dependent fashion, to the point that no inhibition was evident. The results suggest that GABAergic synapses are required for the expression of red/green color opponency in primate bipolar cells.
Mills
S L
SL
Sensory Sciences Center, Graduate School of Biomedical Sciences, University of Texas Health Science Center, Houston.
Sperling
H G
HG
D000818:Animals; D001640:Bicuculline / Q000494:pharmacology*; D003118:Color Perception / Q000187:drug effects*; D004596:Electroretinography / Q000187:drug effects*; D018756:GABA Antagonists; D007267:Injections; D008253:Macaca mulatta; D008297:Male; D009474:Neurons / Q000187:drug effects / Q000502:physiology; D010786:Photoreceptor Cells / Q000187:drug effects / Q000502:physiology; D012684:Sensory Thresholds; D013331:Strychnine / Q000494:pharmacology
D018756:GABA Antagonists; D013331:Strychnine; D001640:Bicuculline