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Maternal obesity accentuates offspring obesity in dams bred to develop diet-induced obesity (DIO) on a 31% fat, high-sucrose, high-energy (HE) diet but has no effect on offspring of diet-resistant (DR) dams. Also, only DIO dams become obese when they and DR dams are fed HE diet throughout gestation and lactation. We assessed glucose and oleic acid (OA) sensitivity of dissociated ventromedial hypothalamic nucleus (VMN) neurons from 3- to 4-wk old offspring of DIO and DR dams fed chow or HE diet using fura-2 calcium imaging to monitor intracellular calcium fluctuations as an index of neuronal activity. Offspring of DIO dams fed chow had ~2-fold more glucose-inhibited (GI) neurons than did DR offspring. This difference was eliminated in offspring of DIO dams fed HE diet. At 2.5 mM glucose, offspring of chow-fed DIO dams had more GI neurons that were either excited or inhibited by OA than did DR offspring. Maternal HE diet intake generally increased the percentage of neurons that were excited and decreased the percentage that were inhibited by OA in both DIO and DR offspring. However, this effect was more pronounced in DIO offspring. These data, as well as concentration-dependent differences in OA sensitivity, suggest that genotype, maternal obesity, and dietary content can all affect the sensitivity of offspring VMN neurons to glucose and long-chain fatty acids. Such altered sensitivities may underlie the propensity of DIO offspring to become obese when fed high-fat, high-sucrose diets. long-chain fatty acids; glucosensing; development; metabolic sensing; epigenetic doi: 10.1152/ajpregu.00370.2009.

Natural selection does not necessarily favor maximal reproduction because reproduction imposes fitness costs, reducing parental survival, and offspring quality. Here, we show that parents in a preindustrial population in North America incurred fitness costs from reproduction, and women incurred greater costs than men. We examined the survivorship and reproductive success (Darwinian fitness) of 21,684 couples married between 1860 and 1895 identified in the Utah Population Database. We found that increasing number of offspring (parity) and rates of reproduction were associated with reduced parental survivorship, and significantly more for mothers than fathers. Parental mortality resulted in reduced survival and reproduction of offspring, and the mothers' mortality was more detrimental to offspring than the fathers'. Increasing family size was associated with lower offspring survival, primarily for later-born children, indicating a tradeoff between offspring quantity versus quality. Also, we found that the costs of reproduction increased with age more for women than men. Our findings help to explain some puzzling aspects of human reproductive physiology and behavior, including the evolution of menopause and fertility declines associated with improvements in women's status (demographic transitions). maternal depletion | menopause | reproductive effort | biodemography | life-history tradeoff

In both men and women, the hormones regulating reproduction form a complex and finely tuned system that affects virtually every cell system in the body. The male reproductive system consists [...]

What we regard as |normal' with respect to human female reproductive physiology differs greatly from the reproductive cycle experienced during most of human existence. Frequent ovulatory menstrual cycles really represent repeated abortive reproductive cycles and are unphysiological. A number of medical conditions, some of great importance, are the result of this change in the character of the reproductive cycle. Suppression of the menstrual cycle offers a means of decreasing the incidence and severity of these medical conditions.

Expression of β-Nerve Growth Factor Receptor mRNA in Sertoli Cells Downregulated by Testosterone TESTICULAR FUNCTION DEPENDS ON local cellular interactions that are influenced by pituitary secretions of luteinizing hormone (LH) [...]

I. INTRODUCTION Fertilization is essential for sexual reproduction and for the generation of a new individual. This fundamental process requires communication between mature and competent male and female gametes so [...]

I am a 25-year-old man with a C5-6 spinal-cord injury (SCI) and wish to father children. Only once have I been completely convinced that I ejaculated in the last 60 [...]

Rates of twinning and other multiple births vary among human populations. From an evolutionary standpoint, multiparous births may increase the fitness of a given mother by increasing her total reproductive performance. On the other hand, these births also carry higher risks for fetal, infant, and maternal mortality, which may reduce reproductive fitness. This study explores twinning in relation to fertility and other reproductive outcomes in one Native American population, the Blackfeet of northern Montana. As part of a larger study, complete reproductive histories were obtained by direct interview of a probability sample of 150 Blackfeet women, ages 18-93 years, living on a reservation in Montana in 1995-1996. In the total sample, 10 of 132 women (7.6%) who ever had been pregnant reported a biparous pregnancy (none reported higher multiples). Of the total 558 births, 20 (3.6%) were twins, with 18 of 549 (3.3%) livebirths. Mothers of twins had significantly higher total livebirths (6.2) compared with mothers producing only singletons (3.99), p=.01. Among women with completed fertility (women 50 yrs and older), 10 of 158 (6.3%) births were twins, with 9 of 154 (5.8%) livebirths. Mean maternal age at twin births in this group was 30.9 yrs. Blackfeet women as represented in this sample have a higher rate of twinning than some populations previously described and evidence of differential fertility in mothers of twins versus mothers of singletons. Additional data concerning rates of fetal and offspring mortality are presented. Implications for fitness are discussed. Supported by an American Lung Association Grant.

I started to have feelings for her in the October. We were in the same class. I presented her with a red rose in an attempt to express my love [...]