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Gonadal and stress hormones modulate neuroplasticity and behaviour. This review focuses on our findings over the past decade on the effects of estrogens and androgens on hippocampal neurogenesis, hippocampus-dependent learning and memory and the effects of reproductive experience in the rodent. Evidence suggests that acute estradiol initially enhances and subsequently suppresses cell proliferation in the dentate gyrus of adult female rodents. Repeated exposure to estradiol modulates hippocampal neurogenesis and cell death in adult female, but not male, rodents while, testosterone and dihydrotestosterone upregulate hippocampal neurogenesis in adult male rodents. Estradiol dose-dependently affects different brain regions involved in working memory (prefrontal cortex, hippocampus), reference memory (hippocampus) and conditioned place preference (amygdala). Pregnancy and motherhood differentially regulate adult hippocampal neurogenesis and spatial working memory in the dam after weaning. These studies and others demonstrate that the female brain responds to steroid hormones differently than the male brain. It is of the upmost importance to investigate the effects on neuroplasticity and behaviour in both the male and the female, particularly when modelling diseases that exhibit sex differences in incidence, etiology or treatment. [ABSTRACT FROM AUTHOR]

Converging evidence indicates that pregnant women report experiencing problems with memory, but the results of studies using objective measures are ambiguous. The present study investigated potential reason(s) for the discrepancy between findings of subjective and objective memory deficits, as well as potential source(s) of pregnant women's problems with memory. Sixty-one pregnant and 24 nonpregnant women completed a series of memory tests which included field and laboratory measures of prospective memory. Three standardized questionnaires were used to assess subjective aspects of memory. The influence of cortisol, depressed mood, anxiety, physical symptoms, sleep/fatigue, and busyness on pregnancy-related deficits was also examined. The findings revealed objective pregnancy-related deficits on two of the field measures of prospective memory. Pregnancy-related subjective deficits were also detected on all of the questionnaires. In contrast, no objective pregnancy-related deficits were found on the laboratory measures of memory. Increased physical symptoms accounted for one of the objective deficits in memory, while depressed mood and physical symptoms accounted for two of the subjective memory deficits. Collectively, these findings suggest that pregnant women experience everyday life problems with memory that are not readily detected in the laboratory environment. The predominant use of laboratory tests may explain the myriad of previous failures to detect objective deficits in pregnant women's memory. [ABSTRACT FROM AUTHOR]