title: Manganese-enhanced MRI to evaluate neurodegenerative changes in a rat model of kainic acid-induced excitotoxicity.
abstract: OBJECTIVE
  Manganese-enhanced magnetic resonance imaging (MEMRI) has been used to detect brain activity based on the ability of active neurons to take up manganese ions through calcium channels. Kainic acid (KA), an analog of excitotoxic glutamate, can elicit selective neuronal death in the brains of rodents, of which the pathological changes partially mimic neurodegeneration in the central nervous system. We used in vivo MEMRI to evaluate neurodegenerative changes in an excitotoxicity model induced by KA in rats.
  
  
  METHODS
  Adult Sprague-Dawley rats (220-250 g) were injected with either KA or saline into the right lateral ventricle. Precontrast and postcontrast MEMRI sessions were obtained. Region of interest (ROI) analyses were performed on both injected (saline and KA) and contralateral (normal) sites in the hippocampal area. All brains were evaluated histologically following MEMRI.
  
  
  RESULTS
  Analysis of percentage change in ROI intensities of T1-weighted fluid-attenuated inversion-recovery MR images in the hippocampal area revealed a significant difference between the KA-injected (ipsilateral) and contralateral sites (P = 0.008), whereas no significant difference was observed between the saline-injected and contralateral sites. Furthermore, there was a significant difference between ipsilateral sites of the saline-treated and KA-treated groups (P = 0.026). The histological results supported these findings.
  
  
  CONCLUSIONS
  MEMRI is a simple and useful in vivo method for detecting neurodegenerative changes due to excitotoxicity in the rat brain. The development of a manganese-based contrast agent that can be safely used in humans is warranted to investigate neurological disorders.
authors.affiliation: Department of Radiology, İzmir Katip Çelebi University Atatürk Education and Training Hospital, İzmir, Turkey. meldapaydin@gmail.com
authors.forename: Melda
authors.initials: M
authors.lastname: Apaydin
authors.forename: Vedat
authors.initials: V
authors.lastname: Evren
authors.forename: Oytun
authors.initials: O
authors.lastname: Erbas
authors.forename: Cem
authors.initials: C
authors.lastname: Calli
authors.forename: Gonul O
authors.initials: GO
authors.lastname: Peker
authors.forename: Dilek
authors.initials: D
authors.lastname: Taskiran
mesh_terms: D000818:Animals; D001921:Brain / Q000187:drug effects / Q000473:pathology*; D001931:Brain Mapping / Q000379:methods*; D004195:Disease Models, Animal; D018690:Excitatory Amino Acid Agonists; D007089:Image Enhancement / Q000379:methods*; D007608:Kainic Acid; D008279:Magnetic Resonance Imaging / Q000379:methods*; D017895:Manganese Compounds; D009410:Nerve Degeneration / Q000139:chemically induced / Q000473:pathology*; D009474:Neurons / Q000187:drug effects / Q000473:pathology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012965:Sodium Chloride / Q000008:administration & dosage
chemical_list: D018690:Excitatory Amino Acid Agonists; D017895:Manganese Compounds; D012965:Sodium Chloride; D007608:Kainic Acid