High-sensitivity rod photoreceptor input to the blue-yellow color opponent pathway in macaque retina.
Small bistratified cells (SBCs) in the primate retina carry a major blue-yellow opponent signal to the brain. We found that SBCs also carry signals from rod photoreceptors, with the same sign as S cone input. SBCs exhibited robust responses under low scotopic conditions. Physiological and anatomical experiments indicated that this rod input arose from the AII amacrine cell-mediated rod pathway. Rod and cone signals were both present in SBCs at mesopic light levels. These findings have three implications. First, more retinal circuits may multiplex rod and cone signals than were previously thought to, efficiently exploiting the limited number of optic nerve fibers. Second, signals from AII amacrine cells may diverge to most or all of the approximately 20 retinal ganglion cell types in the peripheral primate retina. Third, rod input to SBCs may be the substrate for behavioral biases toward perception of blue at mesopic light levels.
Field
Greg D
GD
Salk Institute for Biological Studies, La Jolla, California, USA. gfield@salk.edu
Greschner
Martin
M
Gauthier
Jeffrey L
JL
Rangel
Carolina
C
Shlens
Jonathon
J
Sher
Alexander
A
Marshak
David W
DW
Litke
Alan M
AM
Chichilnisky
E J
EJ
D000200:Action Potentials; D025042:Amacrine Cells / Q000166:cytology / Q000187:drug effects / Q000502:physiology; D000613:Aminobutyrates / Q000494:pharmacology; D000818:Animals; D003116:Color; D018690:Excitatory Amino Acid Agonists / Q000494:pharmacology; D017629:Gap Junctions / Q000187:drug effects / Q000502:physiology; D066298:In Vitro Techniques; D008027:Light; D008252:Macaca fascicularis; D008253:Macaca mulatta; D008839:Microelectrodes; D010775:Photic Stimulation; D012160:Retina / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D051245:Retinal Bipolar Cells / Q000166:cytology / Q000187:drug effects / Q000502:physiology; D017949:Retinal Cone Photoreceptor Cells / Q000187:drug effects / Q000502:physiology; D012165:Retinal Ganglion Cells / Q000187:drug effects / Q000502:physiology*; D017948:Retinal Rod Photoreceptor Cells / Q000187:drug effects / Q000502:physiology*; D013997:Time Factors; D014785:Vision, Ocular / Q000187:drug effects / Q000502:physiology*; D014795:Visual Pathways / Q000166:cytology / Q000187:drug effects / Q000502:physiology*
D000613:Aminobutyrates; D018690:Excitatory Amino Acid Agonists; C012729:2-amino-4-phosphonobutyric acid