cascade—an amplifying strategy reminiscent of that of the rods themselves (43,44). A glutamate receptor activated by the rod transmitter released in darkness appears to continually activate a G protein and in turn a cGMP PDE, which holds the level of cGMP low in darkness. A light-triggered reduction in the activity of the glutamate receptor allows cGMP levels to rise, opening cationic channels in the surface membrane and producing a depolarization which carries the message onward. It will undoubtedly be satisfying to learn more about how synaptic transmission is “ designed” to work in concert with the visual transduction mechanism. Already it appears that synaptic transmission has borrowed a successful molecular strategy from visual transduction itself.

Drs. Leon Lagnado, Clint Makino, Martha Erickson, and Robert Dodd did much of the recent work reported here, and I acknowledge their contributions with many thanks. Drs. Clint Makino, Martha Erickson, and Fred Rieke made useful comments on the manuscript. This research was supported by Grants EY01543 and EY05750 from the National Eye Institute, National Institutes of Health, as well as grants from the Alcon Research Institute, the Ruth and Milton Steinbach Fund, and the McKnight Foundation. Dr. Lubert Stryer's group is a continuing source of stimulating interactions.

1. Yau, K.-W. ( 1994) Invest. Ophthalmol. Visual Sci. 35, 9–32.

2. Pugh, E. N. & Lamb, T. D. ( 1993) Biochim. Biophys. Acta 1141, 111–149.

3. Vuong, T. M. & Chabre, M. ( 1991) Proc. Natl. Acad. Sci. USA 88, 9813–9817.

4. Arshavsky, V. Y. & Bownds, M. D. ( 1992) Nature (London) 357, 416–417.

5. Angleson, J. K. & Wensel, T. G. ( 1994) J. Biol. Chem. 269, 16290–16296.

6. Hecht, S., Shlaer, S. & Pirenne, M. H. ( 1942) J. Gen. Physiol. 25, 819–840.

7. Baylor, D. A., Nunn, B. J. & Schnapf, J. L. ( 1984) J. Physiol. (London) 357, 575–607.

8. Barlow, H. B. ( 1957) J. Physiol. (London) 136, 469–488.

9. Schnapf, J. L., Nunn, B. J., Meister, M. & Baylor, D. A. ( 1990) J. Physiol. (London) 427, 681–713.

10. Watson, A. B. ( 1986) in Handbook of Perception and Human Performance, Sensory Processes and Perception, eds. Boff, K. R., Kaufman, L. & Thomas, J. P. (Wiley, New York), Vol. 1, pp. 6 / 1–6 / 43.

11. Baylor, D. A., Matthews, G. & Yau, K.-W. ( 1980) J. Physiol. (London) 309, 591–621.

12. Aguilar, M. & Stiles, W. S. ( 1954) Optica Acta 1, 59–65.

13. Barlow, H. B. ( 1977) in Vertebrate Photoreception, eds. Barlow, H. B. & Fatt, P. (Academic, London), pp. 337–351.

14. Hubbard, R. ( 1966) J. Biol. Chem. 241, 1814–1818.

15. Aho, A.-C., Donner, K., Hyden, C., Larsen, L. O. & Reuter, T. ( 1988) Nature (London) 334, 348–350.

16. Barlow, H. B. ( 1957) Nature (London) 179, 255–256.

17. Rieke, F., Owen, W. G. & Bialek, W. ( 1991) in Advances in Neural Information Processing 3, eds. Lippman, R., Moody, J. & Touretzky, D. (Kaufmann, New York), pp. 377–383.

18. Barlow, H. B. ( 1956) J. Opt. Soc. Am. 46, 634–639.

19. Lamb, T. D. ( 1981) Vision Res. 21, 1773–1782.

20. Liebrock, C. S., Reuter, T. & Lamb, T. D. ( 1994) Vision Res. 34, 2787–2800.

21. Pugh, E. N. ( 1975) J. Physiol. (London) 248, 413–431.

22. Chen, J., Makino, C. L., Peachey, N. S., Baylor, D. A. & Simon, M. I. ( 1995) Science 267, 374–377.

23. Young, R. W. ( 1971) J. Cell Biol. 49, 303–318.

24. Lagnado, L., Cervetto, L. & McNaughton, P. A. ( 1992) J. Physiol. (London) 455, 111–142.

25. Gray-Keller, M. P. & Detwiler, P. B. ( 1994) Neuron 13, 849–861.

26. McCarthy, S. T., Younger, J. P. & Owen, W. G. ( 1994) Biophys. J. 67, 2076–2089.

27. Cervetto, L., Lagnado, L., Perry, R. J., Robinson, D. W. & McNaughton, P. A. ( 1989) Nature (London) 337, 740–743.

28. Matthews, H. R., Murphy, R. L. W., Fain, G. L. & Lamb, T. D. ( 1988) Nature (London) 334, 67–69.

29. Nakatani, K. & Yau, K.-W. ( 1988) Nature (London) 334, 69–71.

30. Lagnado, L. & Baylor, D.A. ( 1994) Nature (London) 367, 273–277.

31. Hsu, Y. T. & Molday, R. S. ( 1993) Nature (London) 361, 76–79.

32. Gorczyca, W. A., Gray-Keller, M. P., Detwiler, P. B. & Palczewski, K. ( 1994) Proc. Natl. Acad. Sci. USA 91, 4014–4018.

33. Palczewski, K., Subbaraya, I., Gorczyca, W. A., Helekar, B. S., Ruiz, C. C., Ohguro, H., Huang, J., Zhao, X., Crabb, J. W., Johnson, R. S., Walsh, K. A., Gray-Keller, M. P., Detwiler, P. B. & Baehr, W. ( 1994) Neuron 13, 395–404.

34. Dizhoor, A. M., Lowe, D. G., Olshevskaya, E. V., Laura, R. P. & Hurley, J. B. ( 1994) Neuron 12, 1345–1352.

35. Kawamura, S. ( 1993) Nature (London) 362, 855–857.

36. Koutalos, Y. & Yau, K.-W. ( 1995) J. Gen. Physiol. 106, 891–921.

37. Gray-Keller, M. P., Polans, A. S., Palczewski, K. & Detwiler, P. B. ( 1993) Neuron 10, 523–531.

38. Baylor, D. A., Lamb, T. D. & Yau, K.-W. ( 1979) J. Physiol. (London) 288, 613–634.

39. Lyubarsky, A. L., Nikonov, S. S. & Pugh, E. N. ( 1995) Invest. Ophthalmol. Visual Sci. 36, S277.

40. Pepperberg, D. R., Cornwall, M. C., Kahlert, M., Hofmann, K. P., Jin, J., Jones, G. J. & Ripps, H. ( 1992) Visual Neurosci. 8, 9–18.

41. Corson, D. W., Cornwall, M. C. & Pepperberg, D. R. ( 1994) Visual Neurosci. 11, 91–98.

42. Gray, E. G. & Pease, H. L. ( 1971) Brain Res. 35, 1–15.

43. Nawy, S. & Jahr, C. E. ( 1990) Nature (London) 346, 269–271.

44. Shiells, R. A. and Falk, G. ( 1990) Proc. R. Soc. London B 242, 91–94.

Front Matter (R1-R4)

Vision: From photon to perception: An Introduction (1-3)

How photons start vision (4-9)

Gain and kinetics of activation in the G-protein cascade of phototransduction (10-14)

The biology of vision in Drosophila (15-20)

Primate photopigments and primate color vision (21-25)

Circuitry for color coding in the primate retina (26-32)

Cell fate determination in the vertebrate retina (33-39)

Molecular biology of retinal ganglion cells (40-45)

Emergence of order in visual system development (46-52)

Multineuronal codes in retinal signaling (53-58)

Spatial integration and cortical dynamics (59-66)

Computational models of cortical visual processing (67-71)

Motion perception: Seeing and deciding (72-77)

Binocular visual surface perception (78-83)