Magnetic resonance imaging as a tool to image neuroinflammation in a rat model of Parkinson's disease--phagocyte influx to the brain is promoted by bilberry-enriched diet.
Neuroinflammation is a chronic event in neurodegenerative disorders. In the rat model of Parkinson's disease, including a striatal injection of the neurotoxin 6-hydroxydopamine (6-OHDA), antioxidant treatment affects the inflammatory process. Despite a heavy accumulation of microglia early after the injury, dopamine nerve fibre regeneration occurs. It remains unclear why this heavy accumulation of microglia is found early after the lesion in antioxidant-treated animals, or even more, what is the origin of these microglia. In this study magnetic resonance imaging (MRI) was used to elucidate whether the inflammatory response was generated from the blood or from activated brain microglia. Superparamagnetic iron oxide (SPIO) nanoparticles were injected intravenously prior to a striatal 6-OHDA injection to tag phagocytes in the blood. Rats were fed either with bilberry-enriched or control diet. T2*-weighted MRI scans were performed 1 week after the lesion, and hypointense areas were calculated from T2*-weighted images, to monitor the presence of SPIO particles. The results revealed that feeding the animals with bilberries significantly promoted accumulation of blood-derived immune cells. Gadolinium-enhanced MRI demonstrated no difference in leakage of the blood-brain barrier independent of diets. To conclude, bilberry-enriched diet promotes an influx of periphery-derived immune cells to the brain early after injury.
Integrative Medical Biology, Umeå University, SE 901 87, Umeå, Sweden.
Ana
A
Virel
Integrative Medical Biology, Umeå University, SE 901 87, Umeå, Sweden.
Anna
A
Rehnmark
Department of Radiation Sciences, Umeå University, SE 901 87 Umeå, Sweden.
Greger
G
Orädd
Integrative Medical Biology, Umeå University, SE 901 87, Umeå, Sweden.
Sonia
S
Olmedo-Díaz
Integrative Medical Biology, Umeå University, SE 901 87, Umeå, Sweden.
Erik
E
Faergemann
Integrative Medical Biology, Umeå University, SE 901 87, Umeå, Sweden.
Ingrid
I
Strömberg
D000818:Animals; D001812:Blood-Brain Barrier / Q000378:metabolism; D003287:Contrast Media; D004195:Disease Models, Animal; D004660:Encephalitis / Q000473:pathology / Q000503:physiopathology*; D005260:Female; D008279:Magnetic Resonance Imaging / Q000379:methods*; D058185:Magnetite Nanoparticles / Q000008:administration & dosage; D017628:Microglia / Q000378:metabolism / Q000502:physiology*; D009000:Monocytes / Q000378:metabolism / Q000502:physiology*; D017072:Neostriatum / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology*; D016627:Oxidopamine; D020734:Parkinsonian Disorders / Q000139:chemically induced / Q000503:physiopathology*; D010936:Plant Extracts / Q000008:administration & dosage*; D051381:Rats; D017207:Rats, Sprague-Dawley; D029800:Vaccinium myrtillus
D003287:Contrast Media; D058185:Magnetite Nanoparticles; D010936:Plant Extracts; D016627:Oxidopamine
6-OHDA; blood-brain barrier; microglia; superparamagnetic iron oxide nanoparticles