Abstract |
Rod signals in the mammalian retina are thought to reach ganglion cells over the circuit rod-->rod depolarizing bipolar cell-->AII amacrine cell-->cone bipolar cells--> ganglion cells. A possible alternative pathway involves gap junctions linking the rods and cones, the circuit being rod-->cone-->cone bipolar cells--> ganglion cells. It is not clear whether this second pathway indeed relays rod signals to ganglion cells. We studied signal flow in the isolated rabbit retina with a multielectrode array, which allows the activity of many identified ganglion cells to be observed simultaneously while the preparation is stimulated with light and/or exposed to drugs. When transmission between rods and rod depolarizing bipolar cells was blocked by the glutamate agonist 2-amino-4-phosphonobutyric acid (APB), rod input to all On-center and briskly responding Off-center ganglion cells was dramatically reduced as expected. Off responses persisted, however, in Off-center sluggish and On-Off direction-selective ganglion cells. Presumably these responses were generated by the alternative pathway involving rod-cone junctions. This APB-resistant pathway may carry the major rod input to Off-center sluggish and On-Off direction-selective ganglion cells.
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Authors | S H DeVries, D A Baylor |
Journal | Proceedings of the National Academy of Sciences of the United States of America
(Proc Natl Acad Sci U S A)
Vol. 92
Issue 23
Pg. 10658-62
(Nov 07 1995)
ISSN: 0027-8424 [Print] United States |
PMID | 7479860
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, P.H.S.)
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Chemical References |
- Aminobutyrates
- Excitatory Amino Acid Agonists
- 2-amino-4-phosphonobutyric acid
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Topics |
- Aminobutyrates
(pharmacology)
- Animals
- Cell Communication
- Dose-Response Relationship, Radiation
- Electrophysiology
- Excitatory Amino Acid Agonists
(pharmacology)
- In Vitro Techniques
- Light
- Models, Biological
- Rabbits
- Retinal Ganglion Cells
(physiology)
- Retinal Rod Photoreceptor Cells
(drug effects, physiology, radiation effects)
- Vision, Ocular
(physiology)
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