title: Differential Effects of Olanzapine and Haloperidol on MK-801-induced Memory Impairment in Mice.
abstract: OBJECTIVE
  We investigated the differential effects of the antipsychotic drugs olanzapine and haloperidol on MK-801-induced memory impairment and neurogenesis in mice.
  
  
  METHODS
  MK-801 (0.1 mg/kg) was administered 20 minutes prior to behavioral testing over 9 days. Beginning on the sixth day of MK-801 treatment, either olanzapine (0.05 mg/kg) or haloperidol (0.05 mg/kg) was administered 40 minutes prior to MK-801 for the final 4 days. Spatial memory performance was measured using a Morris water maze (MWM) test for 9 days (four trials/day). Immunohistochemistry with bromodeoxyuridine (BrdU) was used to identify newborn cells labeled in tissue sections from the dentate gyrus of the hippocampus.
  
  
  RESULTS
  MK-801 administration over 9 days significantly impaired memory performance in the MWM test compared to untreated controls (p＜0.05) and these deficits were blocked by treatment with olanzapine (p＜0.05) but not haloperidol. The administration of MK-801 also resulted in a decrease in the number of BrdU-labeled cells in the dentate gyrus (28.6%; p＜0.01), which was prevented by treatment with olanzapine (p＜0.05) but not haloperidol.
  
  
  CONCLUSIONS
  These results suggest that olanzapine has a protective effect against cognitive impairments induced by MK-801 in mice via the stimulating effects of neurogenesis.
authors.affiliation: Paik Institute for Clinical Research, Inje University, Busan, Korea.
authors.forename: Jae Chun
authors.initials: JC
authors.lastname: Song
authors.affiliation: Paik Institute for Clinical Research, Inje University, Busan, Korea.
authors.forename: Mi Kyoung
authors.initials: MK
authors.lastname: Seo
authors.affiliation: Paik Institute for Clinical Research, Inje University, Busan, Korea.|Department of Health Science and Technology, Graduate School, Inje University, Busan, Korea.
authors.forename: Sung Woo
authors.initials: SW
authors.lastname: Park
authors.affiliation: Paik Institute for Clinical Research, Inje University, Busan, Korea.|Department of Health Science and Technology, Graduate School, Inje University, Busan, Korea.|Department of Psychiatry, Inje University Haeundae Paik Hospital, Inje University School of Medicine, Busan, Korea.
authors.forename: Jung Goo
authors.initials: JG
authors.lastname: Lee
authors.affiliation: Paik Institute for Clinical Research, Inje University, Busan, Korea.|Department of Health Science and Technology, Graduate School, Inje University, Busan, Korea.|Department of Psychiatry, Inje University Haeundae Paik Hospital, Inje University School of Medicine, Busan, Korea.
authors.forename: Young Hoon
authors.initials: YH
authors.lastname: Kim
keywords: Haloperidol; Memory; NMDA antagonist; Neurogenesis; Olanzapine