• Alzheimer's disease;
  • amyloid β-peptide;
  • oestradiol;
  • menopause;
  • ovariectomy;
  • spatial memory
  • In the present study, we examined whether deprivation of oestrogens by ovariectomy could modify learning and memory deficits caused by a continuous intracerebroventricular (i.c.v.) infusion of amyloid β-peptide (Aβ), the major constituent of senile plaques in AD.

  • Neither long-term (3 months) nor short-term (1 month), deprivation of oestrogens by ovariectomy caused a significant impairment in spatial learning and memory in a water maze and spontaneous alternation behaviour in a Y-maze.

  • A continuous i.c.v. infusion of Aβ-(1-42) caused spatial learning and memory deficits in both ovariectomized and sham-operated rats.

  • The Aβ-induced working memory deficits were significantly potentiated in ovariectomized rats compared with sham-operated rats when mnemonic ability was examined 3 months after ovariectomy.

  • These results suggest that long-term deprivation of oestrogens induced by ovariectomy increases susceptibility to memory deficits produced by Aβ-(1-42) in rats.

British Journal of Pharmacology (1999) 128, 419–427; doi:10.1038/sj.bjp.0702811