title: Omega-3 fatty acids prevent LPS-induced passive avoidance learning and memory and CaMKII-α gene expression impairments in hippocampus of rat.
abstract: BACKGROUND
  Neuroinflammation is considered to be a major factor in several neurodegenerative diseases. Recently, the polyunsaturated fatty acid omega-3 has been shown to have anti-inflammatory effects and might play an effective role in improving memory impairment due to inflammation. In order to test this, we stimulated neuroinflammation in an animal model and induced memory dysfunction as measured by reduced retention of passive avoidance learning (PAL) and altered expression of CaMKII-α, a gene known to be crucial for memory formation. We then investigated whether treatment with dietary omega-3 prevents inflammation-induced memory dysfunction in this model.
  
  
  METHODS
  Male wistar rats (200-220 g) were fed either a control diet or a diet containing omega-3 (400mg/kg, po) for 1 month prior. Rats then received injection of either saline or LPS (500 μg/kg, ip) and were subjected to the PAL acquisition task. The retention test was performed 24h later, and animals were sacrificed immediately. Hippocampi were dissected and stored at -80°C. Finally, TNF-α levels and CaMKII-α gene expression were measured by ELISA and qRT-PCR, respectively.
  
  
  RESULTS
  We found that LPS treatment significantly impaired PAL and memory, increased TNF-α levels and impaired CaMKII-α gene expression. In control and LPS-injected animals, pre-treatment with omega-3 improved performance on the PAL task and increased CAMKII-α gene expression.
  
  
  CONCLUSIONS
  Taken together, these data suggest that dietary omega-3 may improve cognitive function and provide a potential therapy for memory impairment due to neuroinflammation.
authors.affiliation: Department of Biology, Faculty of Science, University of Isfahan, Isfahan, Iran. Electronic address: n.gholamian@yahoo.com.
authors.forename: Neda Gholamian
authors.initials: NG
authors.lastname: Dehkordi
authors.affiliation: Department of Biology, Faculty of Science, University of Isfahan, Isfahan, Iran. Electronic address: mnoorbakhshnia@yahoo.com.
authors.forename: Maryam
authors.initials: M
authors.lastname: Noorbakhshnia
authors.affiliation: Department of Biology, Faculty of Science, University of Isfahan, Isfahan, Iran. Electronic address: kamranghaedi@sci.ui.ac.ir.
authors.forename: Kamran
authors.initials: K
authors.lastname: Ghaedi
authors.affiliation: Department of Biology, Faculty of Science, University of Isfahan, Isfahan, Iran. Electronic address: aesmaeili@sci.ui.ac.ir.
authors.forename: Abolghasem
authors.initials: A
authors.lastname: Esmaeili
authors.affiliation: Department of Biology, Faculty of Science, University of Isfahan, Isfahan, Iran. Electronic address: mohamad.dabaghi@gmail.com.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Dabaghi
mesh_terms: D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects*; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2 / Q000096:biosynthesis / Q000235:genetics*; D004032:Diet; D015525:Fatty Acids, Omega-3 / Q000494:pharmacology*; D015870:Gene Expression / Q000187:drug effects; D006624:Hippocampus / Q000187:drug effects* / Q000378:metabolism*; D008070:Lipopolysaccharides / Q000037:antagonists & inhibitors* / Q000494:pharmacology; D008297:Male; D008569:Memory Disorders / Q000139:chemically induced / Q000517:prevention & control*; D051381:Rats; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D015525:Fatty Acids, Omega-3; D008070:Lipopolysaccharides; D014409:Tumor Necrosis Factor-alpha; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2
keywords: CaMKII-α; Hippocampus; LPS; Memory; Omega-3; Passive avoidance learning