Estrogens have been previously identified as regulators of food reward, or motivated behavior towards food, where high levels are correlated with decreased food motivation. However, only ovarian-derived estrogens have been heavily investigated. Estrogen is primarily produced within the ovaries, but it can also be synthesized in the brain, including in the amygdala, by brain aromatase enzymes that convert androgens into estrogens. Here we hypothesized that brain-produced estrogens are important in the control of food intake and food-motivated behavior in female rats, independently of the function of their ovarian counterparts. To further examine the function of amygdala estrogens on food motivation, estrogen levels specifically within the amygdala were manipulated in female and male rats. Estrogen levels were increased through [beta]-estradiol microinjections to the central amygdala of rats or were decreased by viral gene silencing of the aromatase enzyme (knockdown) specifically in the central amygdala. In addition, we also examined whether the estrous cycle, thus ovarian-produced hormones, interacts with the food motivation effect in intra-amygdala estrogen microinjections. Contrary to our hypothesis, estradiol injections did not affect food motivation, but had an acute effect on food seeking and locomotor activity in female rats, and this effect was estrous cycle dependent. Interestingly, we found that aromatase knockdown within the amygdala decreased food motivation, but only in female rats. These results suggest that brain estrogen manipulations might have a greater effect on female rats, and that brain-produced estrogen and ovarian estrogen might play a divergent role in food-motivated behavior, yet the function of brain-produced estrogen interacts with ovarian hormones.

Recognition that aging is not the accumulation of disease, but rather comprises fundamental biological processes that are amenable to experimental study, is the basis for the recent growth of experimental biogerontology. As increasingly sophisticated studies provide greater understanding of what occurs in the aging brain and how these changes occur

The subject matter in this volume was derived from papers presented at the Pediatric Andrology session of the 1st Pan American Congress of Andrology held in Caracas, Venezuela in February 1979, as well as from selected additional manuscripts of interest in this field. Prior to this session, identification of a distinct discipline and specialty devoted to pediatric andrology had not occurred, nor had it been conceptualized. Pediatric andrology encompasses many different areas: disorders of sexual development, structural disease of the genital organs, normal and abnormal puberty, undescended testes, genital tumors, gonadal function and its relationship to growth, virilization, fertility and gender identity all represent areas of specific interest, to name but a few. Andrology itself is a unique field, bringing together clinicians and basic scientists with diverse back grounds. It should be noted that between one-half and three-quarters of the clinicians contributing to this issue conduct basic research as well. It has been this unique blend of basic research and clinical medicine which has done much to unravel many of these problems characteristic of this field.

It's obvious why only men develop prostate cancer and why only women get ovarian cancer. But it is not obvious why women are more likely to recover language ability after a stroke than men or why women are more apt to develop autoimmune diseases such as lupus. Sex differences in health throughout the lifespan have been documented. Exploring the Biological Contributions to Human Health begins to snap the pieces of the puzzle into place so that this knowledge can be used to improve health for both sexes. From behavior and cognition to metabolism and response to chemicals and infectious organisms, this book explores the health impact of sex (being male or female, according to reproductive organs and chromosomes) and gender (one's sense of self as male or female in society). Exploring the Biological Contributions to Human Health discusses basic biochemical differences in the cells of males and females and health variability between the sexes from conception throughout life. The book identifies key research needs and opportunities and addresses barriers to research. Exploring the Biological Contributions to Human Health will be important to health policy makers, basic, applied, and clinical researchers, educators, providers, and journalists-while being very accessible to interested lay readers.

A comparative overview of the effects of neuropeptides on behavior, examining parallel findings in both humans and non-human animals.