Three distinct blue-green color pathways in a mammalian retina.
In mammalian retinae, the first steps in the process of discrimination of color are mediated by color-opponent neurons that respond with opposite polarity to signals from short (S, blue) and longer wavelength (M, green or L, red) cones. Primates also contain a second system that is different from M and L cones. Although pathways responding to the onset of S-cone stimulation (S-ON) are well known, the existence of bipolar cells and retinal ganglion cells that respond to the offset of S-cone stimulation (S-OFF) has been controversial. We have recorded from and stained three different types of S/M color-opponent ganglion cells in the rabbit retina that are distinguished by the polarity of their responses to S-cone stimulation, the stratification pattern of their dendrites, and the distinct mechanisms underlying their color-opponent responses. We describe an S-ON and an S-OFF pathway formed by amacrine cells inverting the S-ON signal. Most importantly, we also provide both anatomical and physiological evidence for a direct S-OFF pathway dependent on an S-OFF cone bipolar cell. The results indicate a greater diversity of pathways for processing of signals from S-cones than previously suspected.
Department of Ophthalmology and Visual Science, University of Texas at Houston, Houston, Texas 77030, and Department of Anatomy, School of Medicine, Toho University, Tokyo 143-8540, Japan.
Stephen L
SL
Mills
Lian-Ming
LM
Tian
Hideo
H
Hoshi
Christopher M
CM
Whitaker
Stephen C
SC
Massey
D000818:Animals; D001710:Biotin / Q000031:analogs & derivatives / Q000378:metabolism; D048429:Cell Size; D002795:Choline O-Acetyltransferase / Q000378:metabolism; D003118:Color Perception; D055253:Color Vision / Q000187:drug effects / Q000502:physiology*; D005260:Female; D018756:GABA Antagonists; D006531:HEPES / Q000494:pharmacology; D066298:In Vitro Techniques; D008027:Light; D008297:Male; D009433:Neural Inhibition / Q000187:drug effects; D055355:Opsins / Q000378:metabolism; D010775:Photic Stimulation / Q000379:methods; D011422:Propionates / Q000494:pharmacology; D011724:Pyridazines / Q000494:pharmacology; D011817:Rabbits; D018092:Kainic Acid Receptors / Q000378:metabolism; D012160:Retina / Q000166:cytology* / Q000502:physiology*; D017949:Retinal Cone Photoreceptor Cells / Q000187:drug effects / Q000502:physiology*; D012165:Retinal Ganglion Cells / Q000187:drug effects / Q000502:physiology; D014795:Visual Pathways / Q000187:drug effects / Q000502:physiology*
D001710:Biotin; D002795:Choline O-Acetyltransferase; D018756:GABA Antagonists; D006531:HEPES; D055355:Opsins; D011422:Propionates; D011724:Pyridazines; D018092:Kainic Acid Receptors; C114785:2-amino-4-phosphono-propinate; C070614:neurobiotin; C049853:gabazine
color opponency; ganglion cell; retina