The nitric oxide/cyclic GMP pathway in the olfactory processing system of the terrestrial slug Limax marginatus.
To examine the distribution of nitric oxide (NO)-generative cells and NO-responsive cells in the tentacles and procerebral lobes (olfactory processing center) of terrestrial slugs, we applied NADPH diaphorase (NADPH-d) histochemistry and NO-induced cyclic GMP (cGMP)-like immunohistochemistry. We found that NADPH-d reactive cells/fibers and cGMP-like immunoreactive cells/fibers were different, but they were localized adjacent to each other, in both the tentacles and the procerebral lobes. Then, we measured the concentration of NO that was generated around the procerebral lobes using an NO sensitive electrode, when the olfactory nerve was electrically stimulated as a replacement for an odorant stimulus. Stimulation of the olfactory nerve evoked an increase in NO concentration at nanomolar levels, suggesting that binding of nanomolar concentrations of NO to the prosthetic heme group activates soluble guanylyl cyclase. Taken together with previously reported physiological data, our results, therefore, showed that the NO/cGMP pathways are involved in slug olfactory processing.
Fujie
Sayoko
S
Laboratory of Animal Behavior and Intelligence, Division of Biological Sciences, Graduate School of Science, Hokkaido University, Sapporo 060-0810, Japan.
Aonuma
Hitoshi
H
Ito
Iori
I
Gelperin
Alan
A
Ito
Etsuro
E
D000818:Animals; D001921:Brain / Q000201:enzymology / Q000378:metabolism / Q000502:physiology*; D006152:Cyclic GMP / Q000378:metabolism*; D005121:Extremities / Q000502:physiology; D007150:Immunohistochemistry; D008853:Microscopy; D008974:Mollusca / Q000201:enzymology / Q000378:metabolism*; D009252:NADPH Dehydrogenase / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism*; D009832:Olfactory Nerve / Q000502:physiology; D012903:Smell / Q000502:physiology*; D013194:Staining and Labeling
D009569:Nitric Oxide; D009252:NADPH Dehydrogenase; D006152:Cyclic GMP