Two Types of Photoreceptors in the Achromatic Visual System of Helix Pomatia

This study is dedicated to the research of the cellular mechanisms of achromatic vision on plain objects. The photoreceptors of Helix Pomatia (aka Burgundy snail, Roman snail, or «escargot») offer an ideal biological model for the study of the mechanisms of light intensity encoding. This experimental study investigated the assumption of the existence of photoreceptors in the mono-layered retina of Helix Pomatia, characterized by the endogenous, oppositely-fixated reactions to light, while the analysis of the photoreceptors was carried out under conditions of full isolation from synaptic influence. The gathered data allows the confirmation that there are two types of cells in the retina of Helix Pomatia, which react to light conversely: one type hyper-polarizes, while the other type depolarizes when exposed to light; also, that the converse polarization of the receptors’ reaction to light is determined not by intercellular interaction, but by the endogenic characteristics of the photoreceptors, and that in the formation of the receptors’ reaction, the photoreceptors’ de- and hyper-polarizing membranes are effected by various ionic channels.

1. Batuev A. S., Kulikov G. A. (1983). Vvedenie v fiziologiyu sensornyh system. (Introduction to physiology of sensory systems) M.: «Vyshaya shkola».
2. Byzov A. L. (1971). Neirofiziologiya setchatki pozvonochnyh (Neurophysiology of retina of the Vertebrate) // V kn.: Fiziologiya sensornyh system. (In book: Physiology of sensory systems) L.: Nauka.  Ch. I. S. 126–149.
3. Govardovskij V. I., Kuz’min D. G. (1999). Svetoindutsirovannyi vyhod ionov kal’tsia i kinetika kal’tsievoi obratnoi svyazi v palochkah setchatki (Light-induced calcium ion efflux and calcium feedback kinetics in rod cells of retina) // Sensornie systemy. (Sensory systems) T. 13. № 3. S. 213–222.
4. Zaitseva O. V. (1992). Strukturnaya organizatsia sensornyh system ulitki (Structural organization of sensory systems in Helix) // Zhurn. vyssh. nervn. deyat. (Journal of higher nervous activity) T. 42. № 6.  S. 1132–1150. 
5. Zimachev M. M., Shehter E. D., Sokolov E. N., Izmailov Ch. A. (1986). Hromaticheskaya sostavlyayuschaya  elektroretinogrammy lyagushki (Chromatic component of electroretinogram in frog) // Zhurn. vyssh. nervn. deyat. (Journal of higher nervous activity) T. 36. № 6. S. 1100–1107.
6. Izmailov Ch. A., Sokolov E. N. (1984). Tsvetovoe zrenie. (Color vision) M.: Izd-vo MGU. 
7. Izmailov Ch. A., Isaichev S. A., Shehter E. D. (1998). Dvuhkanal’naya model’ razlicheniya signalov v sensornyh systemah (Two-channel model of signal detection in sensory systems) // Vestn. Mosk. un-ta. Ser. 14. Psihologiya. (MSU bulletin. Series 14. Psychology) № 3. S. 29–40.
8. Sokolov E. N. (2003). Vospriyatie i uslovnyi refleks. Novyi vzglyad. (Perception and conditional reflex. A new look) URSS.
9. Firsov M. L., Govardovskij V. I. (2001). Svetovaya adaptatsia fotoretseptorov: smysl i mehanizmy (Color adaptation of photoreceptors: meaning and mechanisms) // Sensornie  systemy (Senory systems). T. 15. № 2. S. 101–113.
10. Fomin S. V., Sokolov E. N., Vaitkyavichus G. G. (1979.) Iskusstvennie organy chuvstv. (Artificial sensory organs) M.: Nauka.
11. Chernorizov M. M., Shehter E. D., Arakelov G. G., Zimachev M. M. (1992). Zrenie vinogradnoi ulitki: spektral’naya  chuvstvitel’nost’ temno-adaptirovannogo glaza (Vision in Helix Pomatia: spectral sensitivity of a dark adaptated eye) // Zhurn. vyssh. nervn. deyat. (Journal of higher nervous activity) T. 42. № 6. S. 1150–1156.
12. Chernorizov M. M. Avtoref. dokt. diss. (Neuronal mechanisms of color perception. PhD thesis) 1999.
13. Shehter E. D., Zimachev M. M., Arakelov G. G. (1992). Zrenie vinogradnoi ulitki. Morfologiya i summarnaya  elektricheskaya aktivnost’ setchatki (Vision in Helix Pomatia. Morphology and summated electrical activity of retina) // Zhurn. vyssh. nervn.deyat. (Journal of higher nervous activity) T. 42. № 5. S. 986–992.
14. Bacigalupo, Chinn J. K., Lisman J. E. (1986). Ion channels activated by light in Limulus ventral photoreceptors. J. Gen. Physiol. V. 87. P. 73–89.
15. Benolken R. M. (1961). Reversal of photoreceptor polarity recorded during the graded receptor potential  response to light in the eye of Limulus. Biophys. J. V .1. P. 55.
16. Dartnall H .J. A. (1953). The interpretation of spectral sensitivity curves. Br. med. Bull. V. 9. P. 24–30.
17. Dorlochter M., Stieve H. (1997). The Limulus ventral photoreceptor: light response and the role of calcium in  a classic preparation. Prog. in Neurobiol. V. 53. P. 451–515. 
18. Eakin R. M., Brandenburger J. l. (1967). Differentiation in the eye of a pulmonate snail Helix aspersa // Ultrastruct. Res. V. 18. № 4. P. 391–421. 
19. Fuortes M. G. F. (1959). Initiation of impulses in visual cells of Limulus. J.Physiol. (London). V. 148. P. 14. 
20. Gillary H. L. (1970). Electrical responses from the eye of Helix to photic stimulation and simultaneous electrical stimulation of the optic nerve // Vision Res. V. 10. № 10. P. 977–991.
21. Gomez M. and Nasi E. (1995). Activation of light-dependent K+ channels in ciliary invertebrate photoreceptors involves cGMP but not IP3/Ca 2+  cascade. Neuron. V. 15. P. 607–618.
22. Heggelund P. (1974). Achromatic color vision. I. Perceptive variables of achromatic colors //Vision Res. V. 14.  P. 1071–1079.
23. Izmailov Ch. A., Sokolov E. N. (1991). Spherical model of color and brightness discrimination // Psychologic.  Science. V. 2. P. 249–259.
24. McReynolds J. S. and Gorman A. L. F. (1970). Photoreceptor potentials of opposite polarity in the eye of the  scallop, Pecten irradians // Gen. Physiol. V. 56. P . 376.
25. Musio C. (2001). Patch-clamping solitary visual cells to understand the cellular mechanisms of inverte- brate phototransduction. Vision: Approach of Biophysics and Neuroscience. Ed. Musio C. Publ. Singapore.  P. 145–164. 
26. Nasi E., Gomez M. (1992). Light-activated ion channels in solitary photoreceptors of the scallop Pecten ir- radians // Gen. Physiol. V. 99. P. 747–769. 
27. Tomita T., Kaneko A., Murakami M., Pautler E. L. (1967). Spectral response curves of single cones in the  carp // Vision Res. V. 7. P .  519–531. 
28. Toyoda J., Hashimoto H., Anno H. and Tomita T. (1970). The rod response in the frog as studied by intracel- lular recording // Vision Res. V. 10. P. 1093–1100. 
29. Von Berg E., Shneider G. (1972). The spectral sensitivity of the dark-adapted eye of Helix pomatia L. //  Vision Res. V. 12. № 12. P . 2151–2152.