Morphological and physiological characteristics of dermal photoreceptors in <i>Lymnaea stagnalis </i>

Abstract

Dermal photoreceptors located in the mantle of Lymnaea stagnalis were histologically and physiologically characterized. Our previous study demonstrated that the shadow response from dermal photoreceptors induces the whole-body withdrawal response. Through the interneuron, RPeD11, we detected that the light-off response indirectly originated from a dermal photoreceptor. Previous observations, based on behavioral pharmacology, revealed that cyclic guanosine monophosphate acts as a second messenger in the dermal photoreceptor. Furthermore, gastropods possess dermal photoreceptors containing rhodopsin, as a photopigment, and another photo-sensitive protein, arrestin, responsible for terminating the light response. Thus, we chose three antibodies, anti-cGMP, anti-rhodopsin, and anti-β-arrestin, to identify the dermal photoreceptor molecules in Lymnaea mantle. Extracellular recording, using a suction electrode on the mantle, revealed a light off-response from the right parietal nerve. Overlapping structures, positive against each of the antibodies, were also observed. Numerous round, granular particles of 3–47 μm in diameter with one nucleus were distributed around pneumostome and/or inside the mantle. The cells surrounding the pneumostome area, located 10 μm beneath the surface, tended to have smaller cell soma ranging from 3 to 25 μm in diameter, while cells located in other areas were distributed uniformly inside the mantle, with a larger diameter ranging from 12 to 47 μm. The histological examination using back-filing Lucifer Yellow staining of the right parietal nerve with the three dermal photoreceptor antibodies confirmed that these overlapping-stained structures were dermal photoreceptors in Lymnaea.

The expression of opsins in the human skin and its implications for photobiomodulation: A Systematic Review

“…Here, we showed several evidence of dermal opsins found in nonhuman animals to understand their biological significance. Current findings from nonhuman animal studies support that dermal opsins mediate dispersed photoreception across the body surface and allow the animals to instantly respond to changes in irradiation of local surrounding 6,11,46 . In animals that face a constant threat of unpredictable environment and predators, dermal photoreception allows them to move away from potential danger, conceal themselves by camouflage or shadow reflex, and control circadian rhythms.…”

Slowly seeing the light: an integrative review on ecological light pollution as a potential threat for mollusks

“…This happens in the marine gastropod Onchidium verruculatum that has additional visual and dermal photoreceptors situated in the dorsal eye and eyestalk. Furthermore, L. stagnalis has been confirmed to have three dermal photoreceptors, one in which cyclic guanosine monophosphate acts as a second messenger in the dermal photoreceptor, a second type that contains rhodopsin as a photopigment, and a third that uses the photosensitive protein, Arrestin (Takigami et al 2014 ).…”

“…Shadow stimulates the predator to attack, whereas it stimulates non-ocular photoreceptors in the snails to send alert signals to the left and right pedal dorsal 11 neurons. These neurons connect to motor neurons 13–16 via chemical synapses and can initiate the escape behavior (Takigami et al 2014 ). This species is even attracted to light when the eyes are experimentally removed (van Duivenboden 1982 ).…”