title: Neonatal repetitive maternal separation causes long-lasting alterations in various neurotrophic factor expression in the cerebral cortex of rats.
abstract: OBJECTIVE
  This study was carried out to examine the effects of early postnatal maternal separation stress on the development of the cerebral cortex with respect to time-dependent fluctuations of neurotrophic factor ligand and receptor expression.
  
  
  METHODS
  Wistar rats were separated from their mothers for 3h per day during postnatal days (PND) 10 to 15. The cerebral cortex was analyzed by real-time RT-PCR for the evaluation of the expression of mRNA for brain-derived neurotrophic factor (BDNF), TrkB, insulin-like growth factor-1 (IGF-1), and type 1 IGF receptor (IGF-1R) on PND16, 20, 30, and 60.
  
  
  RESULTS
  The expression of these neurotrophic factor ligands and receptors in the cerebral cortex was enhanced on PND16 and PND20, and then it returned to baseline levels on PND30. By PND60, however, the expression levels were attenuated.
  
  
  CONCLUSIONS
  The important implication of this study is the persistent abnormal fluctuation of neurotrophic factor expression for a prolonged period, triggered even after the brain growth spurt. Given that neurotrophic factors play important roles in brain development, it can be speculated that the altered expression of these factors induced by maternal separation may interrupt normal brain development and ultimately lead to functional disruption. However, the possibility of such changes leading to various functional disruptions and the underlying mechanisms involved require further study.
authors.affiliation: Department of Health Science, Kongju National University, Chungnam, Republic of Korea.
authors.forename: Kyoung-Youl
authors.initials: KY
authors.lastname: Lee
authors.forename: Takanori
authors.initials: T
authors.lastname: Miki
authors.forename: Toshifumi
authors.initials: T
authors.lastname: Yokoyama
authors.forename: Masaaki
authors.initials: M
authors.lastname: Ueki
authors.forename: Katsuhiko
authors.initials: K
authors.lastname: Warita
authors.forename: Shingo
authors.initials: S
authors.lastname: Suzuki
authors.forename: Ken-Ichi
authors.initials: K
authors.lastname: Ohta
authors.forename: Zhi-Yu
authors.initials: ZY
authors.lastname: Wang
authors.forename: Mostofa
authors.initials: M
authors.lastname: Jamal
authors.forename: Tomiko
authors.initials: T
authors.lastname: Yakura
authors.forename: Jun-Qian
authors.initials: JQ
authors.lastname: Liu
authors.forename: Naohisa
authors.initials: N
authors.lastname: Hosomi
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Takeuchi
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D000831:Animals, Newborn; D019208:Brain-Derived Neurotrophic Factor; D002540:Cerebral Cortex / Q000254:growth & development / Q000378:metabolism*; D017931:DNA Primers / Q000235:genetics; D007334:Insulin-Like Growth Factor I; D008426:Maternal Deprivation; D009414:Nerve Growth Factors / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D060888:Real-Time Polymerase Chain Reaction; D017526:Receptor, IGF Type 1; D017475:Receptors, Nerve Growth Factor / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D019208:Brain-Derived Neurotrophic Factor; D017931:DNA Primers; D009414:Nerve Growth Factors; D017475:Receptors, Nerve Growth Factor; D007334:Insulin-Like Growth Factor I; D017526:Receptor, IGF Type 1