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Updated: May 24, 2026

Modeling Encephalopathy of Prematurity Using Prenatal Hypoxia-ischemia with Intra-amniotic Lipopolysaccharide in Rats
Published on: November 20, 2015
Neonatal repetitive maternal separation causes long-lasting alterations in various neurotrophic factor expression in
Kyoung-Youl Lee1, Takanori Miki, Toshifumi Yokoyama
1Department of Health Science, Kongju National University, Chungnam, Republic of Korea.
Aims:
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.
Main 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.
Key Findings:
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.
Significance:
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.

