title: Insulin treatment prevents the increase in D-serine in hippocampal CA1 area of diabetic rats.
abstract: OBJECTIVE
  Diabetes is a high risk factor for dementia. Employing a diabetic rat model, the present study was designed to determine whether the content of D-serine (D-Ser) in hippocampus is associated with the impairment of spatial learning and memory ability.
  
  
  METHODS
  Diabetes was induced by a single intravenous injection of streptozotocin (STZ). The insulin treatment began 3 days after STZ injection.
  
  
  RESULTS
  We found that both water maze learning and hippocampal CA1 long-term potentiation (LTP) were impaired in diabetic rats. The contents of glutamate, D-Ser, and serine racemase in the hippocampus of diabetic rats were significantly higher than those in the control group. Insulin treatment prevented the STZ-induced impairment in water maze learning and hippocampal CA1-LTP in diabetic rats and also maintained the contents of glutamate, D-Ser, and serine racemase at the normal range in hippocampus.
  
  
  CONCLUSIONS
  These results suggest that insulin treatment has a potent protection effect on CA1-LTP, spatial learning and memory ability of the diabetic rats in vivo. Furthermore, insulin may take effect by inhibiting the overactivation of N-methyl-d-aspartate receptors, which play a critical role in neurotoxicity.
authors.affiliation: Provincial Key Laboratory of Cardiovascular and Cerebrovascular Drug Basic Research, Liaoning Medical University, Jinzhou, China yangjing@lnmu.edu.cn.
authors.forename: Jing
authors.initials: J
authors.lastname: Yang
authors.affiliation: Provincial Key Laboratory of Cardiovascular and Cerebrovascular Drug Basic Research, Liaoning Medical University, Jinzhou, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Song
authors.affiliation: Provincial Key Laboratory of Cardiovascular and Cerebrovascular Drug Basic Research, Liaoning Medical University, Jinzhou, China.
authors.forename: Hongxin
authors.initials: H
authors.lastname: Wang
authors.affiliation: Provincial Key Laboratory of Cardiovascular and Cerebrovascular Drug Basic Research, Liaoning Medical University, Jinzhou, China.
authors.forename: Chunna
authors.initials: C
authors.lastname: Liu
authors.affiliation: Provincial Key Laboratory of Cardiovascular and Cerebrovascular Drug Basic Research, Liaoning Medical University, Jinzhou, China.
authors.forename: Zhongzhe
authors.initials: Z
authors.lastname: Li
authors.affiliation: Provincial Key Laboratory of Cardiovascular and Cerebrovascular Drug Basic Research, Liaoning Medical University, Jinzhou, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Division of Plastic and Reconstructive Surgery, Center for Regenerative Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
authors.forename: Yawei
authors.initials: Y
authors.lastname: Kong
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D056547:CA1 Region, Hippocampal / Q000187:drug effects* / Q000378:metabolism / Q000503:physiopathology; D003921:Diabetes Mellitus, Experimental / Q000188:drug therapy*; D018698:Glutamic Acid / Q000187:drug effects / Q000378:metabolism; D049528:Insulin, Long-Acting / Q000008:administration & dosage / Q000494:pharmacology*; D017774:Long-Term Potentiation / Q000187:drug effects / Q000502:physiology; D008297:Male; D018782:Maze Learning / Q000187:drug effects* / Q000502:physiology; D019998:Racemases and Epimerases / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D012694:Serine / Q000187:drug effects* / Q000378:metabolism; D000099300:Serine Racemase
chemical_list: D018698:Glutamic Acid; D049528:Insulin, Long-Acting; D019998:Racemases and Epimerases; D012694:Serine; D000099300:Serine Racemase
keywords:     d-serine; insulin; long-term potentiation; serine racemase; water maze