The ultrastructure of sensory dendrites following chemical stimulation of the lip of Helix pomatia L.

The ultrastructure of lip of Helix pomatia was investigated after application of distilled water, snail-ringer, sucrose and sodium chloride solutions. In the sensory dendrites, various types and degrees of morphological alterations were found, viz. changes in electron density of dendrites and mitochondria, occurrence of swollen cisternas, appearance of multilamellar and multivesicular bodies, development of electron-dense deposits in mitochondria and smooth-surfaced endoplasmic reticulum, fragmentation of cristae of swollen mitochondria and rearrangement of the smooth-surfaced endoplasmic reticulum. Occasionally, signs of degeneration and focal necrosis were also seen. Using different chemical stimulants, we failed to make morphological distinction between sensory dendrites although the differences in the chemo-specificity of receptors have been shown by electrophysiological investigations.