TY - JOUR
T1 - Effects of 5-HT and insulin on learning and memory formation in food-deprived snails
AU - Aonuma, Hitoshi
AU - Totani, Yuki
AU - Kaneda, Mugiho
AU - Nakamura, Ryota
AU - Watanabe, Takayuki
AU - Hatakeyama, Dai
AU - Dyakonova, Varvara E.
AU - Lukowiak, Ken
AU - Ito, Etsuro
N1 - Funding Information:
This work was supported by a grant from Network Joint Research Center for Materials and Devices in Japan [2015001 to H.A. and E.I.], KAKENHI grants from the Japanese Society for the Promotion of Science [24657055 and 25291074 to E.I.], Waseda University grants for Specific Research Projects in Japan [2016B-068, 2016B-069 and 2016S-037 to E.I.], and a grant from the Natural Sciences and Engineering Research Council of Canada [227993-2013 to K.L.].
Publisher Copyright:
© 2017
PY - 2018/2
Y1 - 2018/2
N2 - The pond snail Lymnaea stagnalis learns conditioned taste aversion (CTA) and consolidates it into long-term memory (LTM). How well they learn and form memory depends on the degree of food deprivation. Serotonin (5-HT) plays an important role in mediating feeding, and insulin enhances the memory consolidation process following CTA training. However, the relationship between these two signaling pathways has not been addressed. We measured the 5-HT content in the central nervous system (CNS) of snails subjected to different durations of food deprivation. One-day food-deprived snails, which exhibit the best learning and memory, had the lowest 5-HT content in the CNS, whereas 5-day food-deprived snails, which do not learn, had a high 5-HT content. Immersing 1-day food-deprived snails in 5-HT impaired learning and memory by causing an increase in 5-HT content, and that the injection of insulin into these snails reversed this impairment. We conclude that insulin rescues the CTA deficit and this may be due to a decrease in the 5-HT content in the CNS of Lymnaea.
AB - The pond snail Lymnaea stagnalis learns conditioned taste aversion (CTA) and consolidates it into long-term memory (LTM). How well they learn and form memory depends on the degree of food deprivation. Serotonin (5-HT) plays an important role in mediating feeding, and insulin enhances the memory consolidation process following CTA training. However, the relationship between these two signaling pathways has not been addressed. We measured the 5-HT content in the central nervous system (CNS) of snails subjected to different durations of food deprivation. One-day food-deprived snails, which exhibit the best learning and memory, had the lowest 5-HT content in the CNS, whereas 5-day food-deprived snails, which do not learn, had a high 5-HT content. Immersing 1-day food-deprived snails in 5-HT impaired learning and memory by causing an increase in 5-HT content, and that the injection of insulin into these snails reversed this impairment. We conclude that insulin rescues the CTA deficit and this may be due to a decrease in the 5-HT content in the CNS of Lymnaea.
KW - Conditioned taste aversion
KW - Feeding
KW - Food-deprivation
KW - Insulin
KW - Lymnaea
KW - Serotonin
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U2 - 10.1016/j.nlm.2017.12.010
DO - 10.1016/j.nlm.2017.12.010
M3 - Article
C2 - 29294381
AN - SCOPUS:85039858792
SN - 1074-7427
VL - 148
SP - 20
EP - 29
JO - Neurobiology of Learning and Memory
JF - Neurobiology of Learning and Memory
ER -