title: The procerebrum is necessary for odor-aversion learning in the terrestrial slug Limax valentianus.
abstract: The terrestrial slug Limax has a highly developed ability to associate the odor of some foods (e.g., carrot juice) with aversive stimuli such as the bitter taste of quinidine solution. The procerebrum (PC) is a part of the slug's brain thought to be involved in odor-aversion learning, but direct evidence is still lacking. Here we present evidence showing that the PC is essential for odor-aversion learning. Unlike sham-operated slugs, PC ablation 7 d prior to conditioning showed that most slugs did not avoid carrot juice in the memory retention test conducted 24 h after the conditioning. Slugs with the PC ablated 3 h, 1 d, 3 d, or 7 d after conditioning and examined by the memory retention test at 3 d after the PC ablation were also less likely to avoid carrot juice than sham-operated slugs. The PC ablation did not damage the ability of the slugs to sense attractive odor (everyday food) or innately aversive odor (onion or garlic). These results demonstrate that the PC is a necessary component in the retention and/or retrieval of odor-aversion memory.
authors.affiliation: Laboratory of Neurobiophysics, School of Pharmaceutical Sciences, The University of Tokyo, Tokyo 113-0033, Japan.
authors.forename: Yoko
authors.initials: Y
authors.lastname: Kasai
authors.forename: Satoshi
authors.initials: S
authors.lastname: Watanabe
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Kirino
authors.forename: Ryota
authors.initials: R
authors.lastname: Matsuo
mesh_terms: D000818:Animals; D001522:Behavior, Animal; D003213:Conditioning, Psychological; D007858:Learning; D008974:Mollusca / Q000502:physiology*; D009812:Odorants; D013687:Telencephalon / Q000033:anatomy & histology / Q000502:physiology*