title: Long-term outcome of changes in cognitive function of young rats after various/different doses of whole brain irradiation.
abstract: OBJECTIVE
  To characterize the early delayed and late-delayed cognitive dysfunction induced by various doses of whole brain irradiation in young rats.
  
  
  METHODS
  One-month-old Sprague-Dawley male rats were divided randomly into the 0 (control), 0 (anesthesia control), 2, 10, 20, and 30-Gy groups. Each group was then subdivided into 4 groups according to the experimental intervals: 1, 2, 3, and 6 months after radiation. Rats were irradiated using a 4-MeV electron beam, which was generated by a linear accelerator. Sequential behavioral tests, including open field, novel location and novel object recognition and Morris water maze were performed after radiation. Changes in gross neurological symptoms, body weight, topical skin response, and histopathology were observed.
  
  
  RESULTS
  In the open field test, there were no radiation-induced alterations found. In the novel location and novel object recognition tests, rats of the 20-Gy group spent less time exploring the novel object and novel location 3 months after irradiation. During the place navigation test, the spatial working memory of the 30 and 20-Gy irradiated rats were impaired from 1 to 2 months after irradiation, respectively. In the spatial probe test, the 20 and 30-Gy irradiated rats spent less time in the critical region compared to control rats at 3 and 6 months post-irradiation. Morphological changes, including edema, vascular dilation, focal necrosis, demyelination, and adjacent reactive gliosis were observed in the 30-Gy irradiation group.
  
  
  CONCLUSIONS
  More than 20 Gy of whole brain irradiation dose can cause significant cognitive dysfunction in young rats.
authors.affiliation: a Department of Radiotherapy & Oncology , The Second Affiliated Hospital of Soochow University , Suzhou , China.
authors.forename: Rui
authors.initials: R
authors.lastname: Sun
authors.affiliation: a Department of Radiotherapy & Oncology , The Second Affiliated Hospital of Soochow University , Suzhou , China.
authors.forename: Li-Yuan
authors.initials: LY
authors.lastname: Zhang
authors.affiliation: a Department of Radiotherapy & Oncology , The Second Affiliated Hospital of Soochow University , Suzhou , China.
authors.forename: Lie-Song
authors.initials: LS
authors.lastname: Chen
authors.affiliation: a Department of Radiotherapy & Oncology , The Second Affiliated Hospital of Soochow University , Suzhou , China.|b Institute of Radiotherapy & Oncology , Soochow University , Suzhou , China.|c Suzhou Key Laboratory for Radiation Oncology , The Second Affiliated Hospital of Soochow University , Suzhou , China.
authors.forename: Ye
authors.initials: Y
authors.lastname: Tian
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001835:Body Weight / Q000528:radiation effects; D001921:Brain / Q000473:pathology / Q000528:radiation effects*; D003072:Cognition Disorders / Q000209:etiology* / Q000473:pathology*; D004195:Disease Models, Animal; D004307:Dose-Response Relationship, Radiation; D005106:Exploratory Behavior / Q000528:radiation effects; D008297:Male; D018782:Maze Learning / Q000528:radiation effects; D009460:Neurologic Examination; D011833:Radiation Injuries, Experimental / Q000150:complications*; D051381:Rats; D017207:Rats, Sprague-Dawley; D021641:Recognition, Psychology / Q000528:radiation effects; D013997:Time Factors
keywords: Brain; Cognitive dysfunction; Radiation; Rat