This preview shows page 1. Sign up to view the full content.
Unformatted text preview: tatory (EPSP) REV: On- and Off-Ganglion Cells LIGHT Na+ channel open in dark NT release in dark IN Dark: NT closes Na+ Channel In Light: Na+ Channel opens Photoreceptor Na+ channel closed in light No NT release in light Depolarizing On-Center Bipolar Cell - + Hyperpolarizing Off-Center Bipolar Cell + On-Center Ganglion Cell + Off-Center Ganglion Cell In Dark: NT opens Na+ Channel In Light: Na+ Channel closes 3 Re5nal Convergence As many as 100 photoreceptors may converge onto a bipolar cell ~ 108 receptors Several bipolars converge onto a single ganglion cell ~ 106 ganglion cells Fig. 6-21, pg. 199 4 Proper5es of Rod & Cone Vision Table 6-3, pg. 207 5 Recep5ve Fields of Ganglion Cells 6 Recep5ve Fields of Ganglion Cells The recep5ve field of a ganglion cell is a circle of photoreceptors in the re5na. A ganglion cell may depolarize or hyperpolarize depending on where light is shone in the recep5ve fie...
View Full Document
- Spring '08