title: [Effects of chronic aluminum exposure on learning and memory and brain-derived nerve growth factor in rats].
abstract: OBJECTIVE
  To investigate the effects of chronic aluminum exposure on the learning and memory abilities and brain-derived nerve growth factor (BDNF) in Sprague-Dawley (SD) rats.
  
  
  METHODS
  Thirty-two male SD rats were randomly and equally divided into 4 groups: control group and high-, middle-, and low-dose exposure groups. The rats in high-, middle-, and low-dose exposure groups were fed with the feed mixed with AlCl(3) (120.0, 12.0, and 1.2 mg/kg, respectively), while the rats in control group were fed conventionally. After 6 months of feeding, brain aluminum levels were determined by inductively coupled plasma mass spectrometry; Morris water maze was employed to test the learning and memory abilities; the expression and content of BDNF in brain tissue were measured by Western blot and enzyme-linked immuno sorbent assay (ELISA).
  
  
  RESULTS
  The high- and middle-dose exposure groups had significantly higher brain aluminum levels than the control group (P<0.05). The Morris water maze test showed that the high- and middle-dose exposure groups had significantly prolonged escape latency (P<0.05), significantly prolonged time taken to first reach the target quadrant (P<0.01), and significantly decreased number of platform crossings and time spent in the target quadrant (P<0.05), as compared with the control group. The Western blot and ELISA showed that the expression and content of BDNF in brain tissue decreased as the dose of AlCl(3) increased, and they were significantly lower in the high- and middle-dose exposure groups than in the control group (P<0.05).
  
  
  CONCLUSIONS
  Chronic aluminum exposure (12.0 and 120.0 mg/kg) can lead to cognitive dysfunction in rats, and the decreased expression of BDNF may be one of the mechanisms of learning and memory deficits induced by aluminum.
authors.affiliation: Center for Disease Control and Prevention, Taiyuan 030003, China.
authors.forename: Bao-long
authors.initials: BL
authors.lastname: Pan
authors.forename: Qiao
authors.initials: Q
authors.lastname: Niu
authors.forename: Ling
authors.initials: L
authors.lastname: Zhang
mesh_terms: D000535:Aluminum / Q000633:toxicity*; D000818:Animals; D001921:Brain / Q000378:metabolism*; D019208:Brain-Derived Neurotrophic Factor / Q000378:metabolism*; D008297:Male; D018782:Maze Learning / Q000187:drug effects*; D051381:Rats; D017207:Rats, Sprague-Dawley; D036401:Toxicity Tests, Chronic
chemical_list: D019208:Brain-Derived Neurotrophic Factor; C019277:brain-derived growth factor; D000535:Aluminum