Abstract | BACKGROUND: METHOD:
Meningitis was induced in male Wistar rats by injecting Streptococcus pneumoniae into the brain through the cisterna magna, and rats were then treated with ceftriaxone. Twenty-four hours and 10 days after meningitis induction, rats were imaged with positron emission tomography (PET) using [11C]PBR28, a specific translocator protein (TSPO) radiotracer, to determine in vivo microglial activation. Following imaging, the expression of TSPO, cardiolipin, and cytochrome c, inflammatory mediators, oxidative stress markers, and glial activation markers were evaluated in the prefrontal cortex and hippocampus. Ten days after meningitis induction, animals were subjected to behavioral tests, such as the open-field, step-down inhibitory avoidance, and novel object recognition tests. RESULTS: Both 24-h (acute) and 10-day (long-term) groups of rats demonstrated increased [11C]PBR28 uptake and microglial activation in the whole brain compared to levels in the control group. Although free from infection, 10-day group rats exhibited increased expression levels of cytokines and markers of oxidative stress, microglial activation (IBA-1), and astrocyte activation (GFAP) similar to those seen in the 24-h group. Acute meningitis induction also elevated TSPO, cytochrome c, and caspase-3 levels with no change in caspase-9 levels. Furthermore, upregulated levels of TSPO, cytochrome c, and caspase-3 and caspase-9 were observed in the rat hippocampus 10 days after meningitis induction with a simultaneous reduction in cardiolipin levels. Animals showed a cognitive decline in all tasks compared with the control group, and this impairment may be at least partially mediated by activating a glia-mediated immune response and upregulating TSPO. CONCLUSIONS:
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Authors | Vijayasree V Giridharan, Allan Collodel, Jaqueline S Generoso, Giselli Scaini, Rico Wassather, Sudhakar Selvaraj, Rodrigo Hasbun, Felipe Dal-Pizzol, Fabricia Petronilho, Tatiana Barichello |
Journal | Journal of neuroinflammation
(J Neuroinflammation)
Vol. 17
Issue 1
Pg. 5
(Jan 04 2020)
ISSN: 1742-2094 [Electronic] England |
PMID | 31901235
(Publication Type: Journal Article)
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Chemical References |
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Topics |
- Animals
- Avoidance Learning
(physiology)
- Cognitive Dysfunction
(diagnostic imaging, metabolism, microbiology)
- Inflammation Mediators
(metabolism)
- Male
- Meningitis
(diagnostic imaging, metabolism, microbiology)
- Positron-Emission Tomography
(methods)
- Rats
- Rats, Wistar
- Streptococcus pneumoniae
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