Ovarian steroids enhance object recognition in naturally cycling and ovariectomized, hormone-primed rats

Learning and memory processes may be influenced by fluctuations in steroid hormones, such as estrogens and progestins. In this study, we have used an animal model to investigate the effects of endogenous fluctuations in ovarian steroids in intact female rats and effects of administration of ovarian steroids to ovariectomized rats for non-spatial, working memory using the object recognition task. Performance in this task relies on cortical and hippocampal function. As such, serum, cortical, and hippocampal concentrations of estradiol (E2), progesterone (P4), and P4's metabolite, 5alpha-pregnan-3alpha-ol-20-one (3alpha,5alpha-THP), were measured by radioimmunoassay. Experiment 1: Rats in behavioral estrus, compared to those in diestrus or estrus, spent a greater percentage of time exploring a novel object concomitant with increases in serum E2, P4, and 3alpha,5alpha-THP levels. Regression analyses revealed that there was a significant positive relationship between E2 levels in the hippocampus and 3alpha,5alpha-THP levels in the hippocampus and cortex and performance in this task. Experiment 2: Administration of E2 and/or P4 immediately post-training increased the percentage of time spent exploring the novel object and produced levels of E2, P4, and 3alpha,5alpha-THP akin to that of rats in behavioral estrus. Experiment 3: Post-training administration of selective estrogen receptor modulators, including 17beta-E2, propyl pyrazole triol, and diarylpropionitrile increased the percentage of time spent exploring the novel object compared to vehicle-administration. Experiment 4: Post-training P4 or 3alpha,5alpha-THP administration, compared to vehicle, increased the percentage of time spent exploring the novel object and produced P4 and/or 3alpha,5alpha-THP levels within the physiological range typically observed for rats in behavioral estrus. Experiment 5: If post-training administration of E2 and/or P4 was delayed one hour, no enhancement in object recognition was observed. Together, these results suggest that E2 and progestins can have mnemonic effects through actions in the cortex and/or hippocampus.     

ERbeta-selective SERMs produce mnemonic-enhancing effects in the inhibitory avoidance and water maze tasks

Estradiol (17beta-E2) can have mnemonic-enhancing effects; however, its mechanisms for these effects are not well-understood. The present studies examined effects of 17beta-E2 and selective estrogen receptor modulators (SERMs) on emotional and spatial memory of female, Long-Evans rats. First, whether or not 17beta-E2 has dose-dependent effects on inhibitory avoidance memory was investigated. Only the highest concentration of 17beta-E2 examined (10 microg), which produces physiological concentrations of E2, was effective at enhancing inhibitory avoidance memory (Experiment 1). Further studies were designed to elucidate whether SERMs may produce mnemonic effects similar to those of 17beta-E2. Compounds utilized were, the ERalpha-selective SERMs, propyl pyrazole triol (PPT) or 17alpha-E2, the ERbeta-specific SERMs, diarylpropionitrile (DPN) or 7,12-dihydrocoumestan (coumestrol), or vehicle (oil). Post-training administration of 10 microg 17beta-E2 or coumestrol enhanced memory in the inhibitory avoidance task compared to vehicle (Experiment 2). Memory in the water maze was enhanced by post-training administration of 17beta-E2, coumestrol, or DPN, compared to vehicle (Experiment 3). Co-administration of 17alpha-E2&DPN enhanced inhibitory avoidance memory similar to that seen following 17beta-E2 or coumestrol (Experiment 4). Administration of E2 2 h post-training was not effective at enhancing memory in the inhibitory avoidance or water maze tasks (Experiment 5). Lordosis of rats was enhanced by 17beta-E2, 17alpha-E2, or PPT, compared to vehicle (Experiment 6). These data suggest that: E2's actions at ERbeta, rather than ERalpha, may enhance spatial memory, E2's actions at ERalpha can facilitate sexual behavior, and that E2's actions involving both ERalpha and ERbeta may be important for emotional memory.     

Modes of cognitive control in recognition and source memory: Depth of retrieval

Recognition memory is usually regarded as a judgment based on trace strength or familiarity. But recognition may also be accomplished by constraining retrieval so that only sought after information comes to mind (source-constrained retrieval). We introduce amemory-for-foils paradigm that provides evidence for source-constrained retrieval in recognition memory (Experiment 1) and source memory (Experiment 2). In this paradigm, subjects studied words under deep or shallow encoding conditions and were given a memory test (recognition or source) that required them to discriminate between new items (foils) and either deep or shallow targets. A final recognition test was used to examine memory for the foils. In both experiments, foil memory was superior when subjects attempted to retrieve deep rather than shallow targets on the earlier test. These findings support a sourceconstrained retrieval view of cognitive control by demonstrating qualitative differences in the basis for memory performance.     

Sex differences in the links between attractiveness, self-esteem and the body

Two studies were conducted to determine: if the links between the body and self-perceived attractiveness and self-esteem for men and women differ. Following evolutionary and social learning theories, affective and cognitive links were hypothesized for women's attractiveness while no links were hypothesized for men's attractiveness. Additionally, affective links were expected for women's self-esteem while no links were expected for men's self-esteem. The results obtained supported these hypotheses. Findings are discussed in terms of the societal value placed on women's attractiveness and evolutionary theory.     

Why do battered women stay?: Three decades of research

A review of the domestic violence research was conducted to assess the most salient factors that predict the likelihood of a woman remaining in or leaving an abusive relationship. The research is still in its early stage and no single theory can confidently predict this tendency on the part of battered women. Research that currently appears to provide the best explanations for remaining in an abusive relationship and factors that enable women to end their abuse are summarized.     

Olfactory context and memory retrieval in 3-month-old infants

Three experiments examineed whether olfactory stimuli can produce context-dependent effects in infant memory. In eash, 3-month-old infants learned to kick to control the movement of an overhead modile in the presence of an ambient odor. Retention was assessed 1, 3, or 5 days later. During the retention test, the olfactory context was either the same odor, a different odor, or “no odor.” At 1 day, infants exhibited retention when tested in the presence of the same odor. Infants in the no odor condition exhibited partial retention, whereas memory retrieval was completely disrupted for infants tested in the presence of the different odor. After the 3- and 5-day intervals, all groups showed forgetting. These results were not consistent with recent studies of 3-month-old infants trained and tested in the presence of a distinctive visual and auditory context. The findings suggest that olfactory stimuli are a silent feature of the environment for 3-month-old infants, but that they function as context cues in a way that differs from other sensory modalities.     

Why do battered women stay?: Three decades of research

A review of the domestic violence research was conducted to assess the most salient factors that predict the likelihood of a woman remaining in or leaving an abusive relationship. The research is still in its early stage and no single theory can confidently predict this tendency on the part of battered women. Research that currently appears to provide the best explanations for remaining in an abusive relationship and factors that enable women to end their abuse are summarized.     

Reentry Women: A Literature Review With Recommendations for Counseling and Research

This article is a comprehensive literature review of the research regarding reentry women for 1980 to 1990, with recommendations for counseling and research. The article is divided into the following sections: (a) reentry trends; (b) general characteristics; (c) reasons for reentry; (d) personality; (e) role, values, and family; (f) satisfaction in the student role; (g) career choice; (h) reentry women after graduation; (i) research limitations; (j) research recommendations; and (k) conclusion. Research replications were found to be very limited and restricted to four areas: (a) reasons for reentry, (b) personality, (c) family variables, and (d) career choice.