title: Modulation of behavior and glutamate receptor mRNA expression in rats after sub-chronic administration of benzo(a)pyrene.
abstract: OBJECTIVE
  The present study aimed to test whether exposure to benzo(a)pyrene [B(a)P] affects spatial learning and short-term memory by modulating the expression of the Gria1 and Grin2a glutamate receptor subunit genes in the hippocampus.
  
  
  METHODS
  Thirty-six 21-24-day-old, male rats were randomly assigned into high-, medium-, and low-dose toxin exposure groups (6.25, 2.5, and 1 mg/kg, respectively) and a control group, each containing nine rats. The behavioral performance of adult rats exposed to sub-chronic administration of B(a)P was monitored by learning and memory tests (Morris water maze). Real-time PCR assays were used to quantify Gria1 and Grin2a gene expression in the hippocampus.
  
  
  RESULTS
  At medium and high doses, B(a)P impaired spatial learning performance. The crossing-platform-location frequency and the time spent swimming in the platform area, which both relate to short-term memory, were significantly decreased in B(a)P-treated rats compared with controls. The level of Gria1 mRNA increased 2.6-5.9-fold, and the level of Grin2a mRNA increased 10-14.5-fold, with a greater fold increase associated with higher doses of B(a)P.
  
  
  CONCLUSIONS
  We demonstrated that sub-chronic administration of B(a)P inhibits spatial learning and short-term memory, and increases Gria1 and Grin2a expression in the hippocampus. This suggests a relationship of B(a)P exposure levels with Gria1 and Grin2a expression and impairment of short-term and spatial memory.
authors: Department of Occupational and Environmental Medicine, Chongqing Medical University, Chongqing, Sichuan, China.
authors: Qian
authors: Q
authors: Tang
authors: YinYin
authors: Y
authors: Xia
authors: ShuQun
authors: S
authors: Cheng
authors: BaiJie
authors: B
authors: Tu
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D001564:Benzo(a)pyrene / Q000008:administration & dosage / Q000633:toxicity*; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D005786:Gene Expression Regulation / Q000187:drug effects*; D006624:Hippocampus / Q000378:metabolism; D007858:Learning / Q000187:drug effects; D008297:Male; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism*; D051381:Rats; D018091:Receptors, AMPA / Q000235:genetics / Q000378:metabolism*; D016194:Receptors, N-Methyl-D-Aspartate / Q000235:genetics / Q000378:metabolism*
chemical_list: D001564:Benzo(a)pyrene; D012333:RNA, Messenger; D018091:Receptors, AMPA; D016194:Receptors, N-Methyl-D-Aspartate