title: Perinatal exposure to genistein, a soy phytoestrogen, improves spatial learning and memory but impairs passive avoidance learning and memory in offspring.
abstract: This study investigated the effects of perinatal genistein (GEN) exposure on the central nervous system of rat offspring. Pregnant dams orally received GEN (1 or 10 mg/kg/day) or vehicle (1 ml/kg/day) from gestation day 10 to postnatal day 14. In order to assess the effects of GEN on rat offspring, we used a battery of behavioral tests, including the open-field, elevated plus-maze, MAZE and step-through passive avoidance tests. MAZE test is an appetite-motivation test, and we used this mainly for assessing spatial learning and memory. In the MAZE test, GEN groups exhibited shorter latency from start to goal than the vehicle-treated group in both sexes. On the other hand, performances in the step-through passive avoidance test were non-monotonically inhibited by GEN in both sexes, and a significant difference was observed in low dose of the GEN-treated group compared to the vehicle-treated group in female rats. Furthermore, we found that perinatal exposure to GEN did not significantly alter locomotor activity or emotionality as assessed by the open-field and elevated-plus maze tests. These results suggest that perinatal exposure to GEN improved spatial learning and memory of rat offspring, but impaired their passive avoidance learning and memory.
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: Rika
authors.initials: R
authors.lastname: Kuwahara
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: Graduate School of Fisheries Science and Environmental Studies, Nagasaki University, Nagasaki 852-8521, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Jojima
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: D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D004644:Emotions / Q000187:drug effects; D005260:Female; D019833:Genistein / Q000494:pharmacology*; D008297:Male; D018782:Maze Learning / Q000187:drug effects; D008568:Memory / Q000187:drug effects*; D009043:Motor Activity / Q000187:drug effects; D009483:Neuropsychological Tests; D048789:Phytoestrogens / Q000494:pharmacology*; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D017207:Rats, Sprague-Dawley; D012727:Sex Characteristics; D065853:Spatial Learning / Q000187:drug effects*; D065852:Spatial Memory / Q000187:drug effects; D013647:Task Performance and Analysis
chemical_list: D048789:Phytoestrogens; D019833:Genistein
keywords: Behavior; Central nervous system; Genistein; Isoflavone; Non-monotonic dose response; Perinatal exposure