title: Male Hatano high-avoidance rats show high avoidance and high anxiety-like behaviors as compared with male low-avoidance rats.
abstract: Our prime objective was to establish an optimal model animal for studying avoidance learning and memory in rodents. The two-way rat inbred strains of Hatano high- (HAA) and low-avoidance (LAA) animals were originally selected and bred in accordance with their high or low performance respectively in the shuttle-box active avoidance task. Previous studies demonstrated that they have clear strain differences in endocrine stress response, which is related to acquisition of aversive learning and emotional reactivity. To evaluate the effect of selection by the shuttle-box task on avoidance performance and emotional reactivity, male Hatano rats underwent passive avoidance, open field and elevated plus maze tests. The present results show that the avoidance performance in the passive task was significantly greater in HAA rats than in LAA rats. Furthermore, HAA rats showed high anxiety-like behaviors compared with LAA rats in open field and elevated plus maze tests. Taken together, this study demonstrated that 1) selection and breeding of Hatano HAA and LAA strain rats by shuttle-box task had been properly carried out with the criterion of high and low avoidance performance respectively and that 2) HAA rats were predisposed to high anxiety compared with LAA rats. These results indicated that Hatano HAA and LAA rats can be useful models for studying avoidance learning and memory.
authors.affiliation: Department of Basic Veterinary Science, United Graduate School of Veterinary Sciences, Gifu University, 1-1 Yanagido, Gifu, Gifu 501-1193, Japan.
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Horii
authors.forename: Maiko
authors.initials: M
authors.lastname: Kawaguchi
authors.forename: Ryo
authors.initials: R
authors.lastname: Ohta
authors.forename: Akihiro
authors.initials: A
authors.lastname: Hirano
authors.forename: Gen
authors.initials: G
authors.lastname: Watanabe
authors.forename: Nobumasa
authors.initials: N
authors.lastname: Kato
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Himi
authors.forename: Kazuyoshi
authors.initials: K
authors.lastname: Taya
mesh_terms: D000367:Age Factors; D000818:Animals; D001007:Anxiety; D001362:Avoidance Learning; D001947:Breeding; D008297:Male; D018782:Maze Learning; D008568:Memory; D023421:Models, Animal; D051381:Rats / Q000235:genetics / Q000502:physiology*; D011919:Rats, Inbred Strains