title: Effects of preweaning environmental enrichment on hippocampus-dependent learning and memory in developing rats.
abstract: Previous studies have shown that environmental enrichment (EE) improves learning and memory in adult animals. However, the effects of preweaning EE (preEE) on hippocampus-dependent learning and memory as well as its possible mechanisms are poorly understood. Here we report that preEE enhanced the exploratory activity in rats immediately after weaning, and the EE group showed greater performance in a passive avoidance task than the control group (p<0.05), but not in the locomotion activity. Electrophysiology analysis showed that rats exposed to preEE exhibited larger field excitatory postsynaptic potentials after long-term potentiation induction than those in the control group (p<0.05). The protein levels of phosphorylated extracellular signal-regulated kinases as well as activity-regulated cytoskeleton-associated protein were significantly upregulated in the preEE group compared to the control group (p<0.05). Our results indicate that preEE can enhance hippocampus-dependent learning and memory function as postweaning EE does, and the upregulated activation of the ERK signal transduction pathway may be the underlying molecular mechanism.
authors.affiliation: MOE-Shanghai Key Laboratory of Children's Environmental Health, Xinhua Hospital affiliated to Shanghai Jiaotong University School of Medicine, Shanghai, 200092, China; Obstetrics and Gynecology Hospital of Fudan University, Shanghai, 200011, China.
authors.forename: Cheng-Qiu
authors.initials: CQ
authors.lastname: Lu
authors.affiliation: MOE-Shanghai Key Laboratory of Children's Environmental Health, Xinhua Hospital affiliated to Shanghai Jiaotong University School of Medicine, Shanghai, 200092, China.
authors.forename: Le
authors.initials: L
authors.lastname: Zhong
authors.affiliation: MOE-Shanghai Key Laboratory of Children's Environmental Health, Xinhua Hospital affiliated to Shanghai Jiaotong University School of Medicine, Shanghai, 200092, China.
authors.forename: Chong-Huai
authors.initials: CH
authors.lastname: Yan
authors.affiliation: MOE-Shanghai Key Laboratory of Children's Environmental Health, Xinhua Hospital affiliated to Shanghai Jiaotong University School of Medicine, Shanghai, 200092, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Tian
authors.affiliation: MOE-Shanghai Key Laboratory of Children's Environmental Health, Xinhua Hospital affiliated to Shanghai Jiaotong University School of Medicine, Shanghai, 200092, China. Electronic address: xmshen@shsmu.edu.cn.
authors.forename: Xiao-Ming
authors.initials: XM
authors.lastname: Shen
mesh_terms: D000818:Animals; D001362:Avoidance Learning; D001835:Body Weight; D003598:Cytoskeletal Proteins / Q000378:metabolism; D004777:Environment; D005106:Exploratory Behavior; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D006624:Hippocampus / Q000502:physiology*; D007858:Learning; D017774:Long-Term Potentiation; D008568:Memory; D009043:Motor Activity; D009419:Nerve Tissue Proteins / Q000378:metabolism; D010766:Phosphorylation; D017207:Rats, Sprague-Dawley; D014886:Weaning
chemical_list: D003598:Cytoskeletal Proteins; D009419:Nerve Tissue Proteins; C092069:activity regulated cytoskeletal-associated protein; D048049:Extracellular Signal-Regulated MAP Kinases
keywords: Activity-regulated cytoskeleton-associated protein; Enriched environment; Extracellular signal-regulated kinases; Learning and memory; Preweaning