title: Genistein improves spatial learning and memory in male rats with elevated glucose level during memory consolidation.
abstract: Cognitive dysfunction due to higher blood glucose level has been reported previously. Genistein (GEN) is a phytoestrogen that we hypothesized might lead to improved memory, despite elevated blood glucose levels at the time of memory consolidation. To investigate this hypothesis, we compared the effects of orally administered GEN on the central nervous system in normal versus glucose-loaded adult male rats. A battery of behavioral assessments was carried out. In the MAZE test, which measured spatial learning and memory, the time of normal rats was shortened by GEN treatment compared to the vehicle group, but only in the early stages of testing. In the glucose-loaded group, GEN treatment improved performance as mazes were advanced. In the open-field test, GEN treatment delayed habituation to the new environment in normal rats, and increased the exploratory behaviors of glucose-loaded rats. There were no significant differences observed for emotionality or fear-motivated learning and memory. Together, these results indicate that GEN treatment improved spatial learning and memory only in the early stages of testing in the normal state, but improved spatial learning and memory when glucose levels increased during memory consolidation.
authors.affiliation: Graduate School of Fisheries Science and Environmental Studies, Nagasaki University, Nagasaki 852-8521, Japan.
authors.forename: Yumi
authors.initials: Y
authors.lastname: Kohara
authors.affiliation: Graduate School of Science and Technology, Nagasaki University, Nagasaki 852-8521, Japan.
authors.forename: Shinichiro
authors.initials: S
authors.lastname: Kawaguchi
authors.affiliation: Division of Environmental Chemistry and Ecotoxicology, Institute of Environmental Studies, Graduate School of Fisheries Science and Environmental Studies, Nagasaki University, Nagasaki 852-8521, Japan.
authors.forename: Rika
authors.initials: R
authors.lastname: Kuwahara
authors.affiliation: Graduate School of Fisheries Science and Environmental Studies, Nagasaki University, Nagasaki 852-8521, Japan.
authors.forename: Yutaro
authors.initials: Y
authors.lastname: Uchida
authors.affiliation: Graduate School of Fisheries Science and Environmental Studies, Nagasaki University, Nagasaki 852-8521, Japan.
authors.forename: Yushi
authors.initials: Y
authors.lastname: Oku
authors.affiliation: Division of Environmental Chemistry and Ecotoxicology, Institute of Environmental Studies, Graduate School of Fisheries Science and Environmental Studies, Nagasaki University, Nagasaki 852-8521, Japan. Electronic address: kimihiro@nagasaki-u.ac.jp.
authors.forename: Kimihiro
authors.initials: K
authors.lastname: Yamashita
mesh_terms: D000284:Administration, Oral; D000704:Analysis of Variance; D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects; D001786:Blood Glucose / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D005106:Exploratory Behavior / Q000187:drug effects; D005215:Fasting; D019833:Genistein / Q000008:administration & dosage*; D008297:Male; D018782:Maze Learning / Q000187:drug effects; D048789:Phytoestrogens / Q000008:administration & dosage*; D051381:Rats; D017207:Rats, Sprague-Dawley; D065853:Spatial Learning / Q000187:drug effects*; D065852:Spatial Memory / Q000187:drug effects*
chemical_list: D001786:Blood Glucose; D048789:Phytoestrogens; D019833:Genistein
keywords: Genistein; Glucose load; Oral administration; Phytoestrogen; Rat; Spatial learning