title: The Yerkes-Dodson law and appropriate stimuli for conditioned taste aversion in Lymnaea.
abstract: The pond snail Lymnaea stagnalis can learn conditioned taste aversion and then consolidate it into long-term memory (LTM). A high-voltage electric shock was used as the unconditioned stimulus, where we have previously used KCl. We varied the strength of both the conditioned and unconditioned stimuli to determine whether the so-called Yerkes-Dodson law prevailed. This is an empirical relationship between the state of arousal and LTM formation, showing that there is an optimal level of arousal leading to memory formation. However, too little or too much arousal results in poorer LTM. We found here that the most appropriate stimuli to use in taste aversion training in Lymnaea were a 10 mmol l(-1) sucrose solution as the conditioned stimulus and a 3 s electric shock as the unconditioned stimulus.
authors.affiliation: Laboratory of Functional Biology, Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University, Sanuki 769-2193, Japan eito@kph.bunri-u.ac.jp.
authors.forename: Etsuro
authors.initials: E
authors.lastname: Ito
authors.affiliation: Laboratory of Functional Biology, Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University, Sanuki 769-2193, Japan.
authors.forename: Miki
authors.initials: M
authors.lastname: Yamagishi
authors.affiliation: Department of Biological Science and Technology, School of High-Technology for Human Welfare, Tokai University, Numazu 410-0321, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Takigami
authors.affiliation: Department of Biological Science and Technology, School of High-Technology for Human Welfare, Tokai University, Numazu 410-0321, Japan.
authors.forename: Manabu
authors.initials: M
authors.lastname: Sakakibara
authors.affiliation: Department of Systems Neuroscience, School of Medicine, Sapporo Medical University, Sapporo 060-8556, Japan.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Fujito
authors.affiliation: Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada, T2N 4N1.
authors.forename: Ken
authors.initials: K
authors.lastname: Lukowiak
mesh_terms: D000818:Animals; D001362:Avoidance Learning; D003214:Conditioning, Classical; D004558:Electric Stimulation; D008195:Lymnaea / Q000502:physiology*; D008568:Memory / Q000502:physiology; D013395:Sucrose; D013649:Taste
chemical_list: D013395:Sucrose
keywords: Conditioned taste aversion; Electric shock; Lymnaea; Yerkes–Dodson law