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.

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