Experimentally Induced Sepsis Causes Extensive Hypomyelination in the Prefrontal Cortex and Hippocampus in Neonatal Rats

This study aimed to explore if systemic lipopolysaccharide (LPS) injection would induce hypomyelination in the prefrontal cortex and hippocampus in developing septic neonatal rats. Sprague –Dawley rats (1-day old) were injected with LPS (1 mg/kg) intraperitoneally. By electron microscopy, axonal hypomyelination was evident in the subcortical white matter and hippocampus. The expression of myelin proteins including CNPase, MBP, PLP and MAG was downregulated in both areas of the brai n at 7, 14 and 28 days after LPS injection. The frequency of MBP and PLP-positive oligodendrocyte was significantly reduced using in situ hybridization in the cerebral cortex and hippocampus at the corresponding time points after LPS injection, whereas the expression of NG2 and PDGFRα was noticeabl y increased. In tandem with this was reduction of Olig1 and Olig2 expressions which are involved in differentiation/maturation of OPCs. Expression of NFL, NFM, and NFH was significantly downregulated, indicating that axon development was disrupted after LPS injection. Morris Water Maze behavioral te st, Open field test, Rotarod test, and Pole test were used to evaluate neurological behaviors of 28 days rats. The rats in the LPS group showed the impairment of motor coordination, balance, memory, and learning ability and represented bradykinesia and anxiety-like behavior. The present results sugg est that following systemic LPS injection, differentiation/maturation of OPCs was affected which may be att...
Source: NeuroMolecular Medicine - Category: Neurology Source Type: research