Distribution and physiological effect of enterin neuropeptides in the olfactory centers of the terrestrial slug Limax

• Published in: Journal of Comparative Physiology Vol. 206; no. 3; pp. 401 - 418
• Main Authors: Matsuo, Ryota, Kobayashi, Suguru, Furuta, Arisa, Osugi, Tomohiro, Takahashi, Toshio, Satake, Honoo, Matsuo, Yuko
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.05.2020; Springer Nature B.V
• Subjects: Animal Physiology; Animals; Biomedical and Life Sciences; Central nervous system; Cerebrum - metabolism; Electrophysiological recording; Gastropoda; Interneurons; Interneurons - metabolism; Life Sciences; Limax; Motor systems; Neurons; Neuropeptides; Neuropeptides - metabolism; Neurosciences; Olfaction; Olfactory discrimination learning; Olfactory Pathways - metabolism; Original Paper; Patch-Clamp Techniques; Physiological effects; Potential oscillations; Smell - physiology; Terrestrial environments; Vascular system; Zoology; Enterin; Field potential oscillation; Acetylcholine; Procerebral lobe; Lehmannia
• ISSN: 0340-7594; 1432-1351
• DOI: 10.1007/s00359-020-01400-2

In gastropods, the function of neuropeptides has been studied primarily in the peripheral motor systems. Their functional roles in the central nervous system have received less attention. The procerebrum, the secondary olfactory center of the terrestrial slug Limax , consists of several hundred thousand interneurons, and plays a pivotal role in olfactory learning and memory. In the present study, we found that enterin, known as a myoactive peptide functioning in the enteric and vascular system of Aplysia , is expressed in the procerebrum of Limax . These enterin-expressing neurons primarily make projections within the cell mass layer of the procerebrum. The oscillatory frequency of the local field potential in the procerebrum was reduced by an exogenous application of enterin. The local field potential oscillation in the tentacular ganglion, the primary olfactory center, was also modulated by enterin. Whole-cell patch-clamp recordings revealed that the modulatory effect in the procerebrum was due to the inhibitory effect of enterin on the bursting neurons, which function as the kernels determining the oscillatory activity of the procerebrum. Our results revealed the novel role of the myoactive neuropeptide enterin in the higher olfactory function in terrestrial gastropods.