Systemic LPS administration induces brain inflammation but not dopaminergic neuronal death in the substantia nigra.
It has been suggested that brain inflammation is important in aggravation of brain damage and/or that inflammation causes neurodegenerative diseases including Parkinson's disease (PD). Recently, systemic inflammation has also emerged as a risk factor for PD. In the present study, we evaluated how systemic inflammation induced by intravenous (iv) lipopolysaccharides (LPS) injection affected brain inflammation and neuronal damage in the rat. Interestingly, almost all brain inflammatory responses, including morphological activation of microglia, neutrophil infiltration, and mRNA/protein expression of inflammatory mediators, appeared within 4-8 h, and subsided within 1-3 days, in the substantia nigra (SN), where dopaminergic neurons are located. More importantly, however, dopaminergic neuronal loss was not detectable for up to 8 d after iv LPS injection. Together, these results indicate that acute induction of systemic inflammation causes brain inflammation, but this is not sufficiently toxic to induce neuronal injury.
Neuroscience Graduate Program, Ajou University School of Medicine, Suwon 442-721, Korea.
Hey-Kyeong
HK
Jeong
Ilo
I
Jou
Eun-hye
EH
Joe
D000818:Animals; D001253:Astrocytes / Q000473:pathology; D016923:Cell Death; D004660:Encephalitis / Q000139:chemically induced / Q000276:immunology / Q000473:pathology*; D007275:Injections, Intravenous; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008297:Male; D017628:Microglia / Q000473:pathology; D020556:Neutrophil Infiltration; D051381:Rats; D017207:Rats, Sprague-Dawley; D013378:Substantia Nigra / Q000276:immunology / Q000473:pathology*
D008070:Lipopolysaccharides