This study suggests that approximately half of exercising women experience subtle menstrual disturbances, i.e. LPD and anovulation, and that one third of exercising women may be amenorrheic. Estimates of the prevalence of subtle menstrual disturbances in exercising women determined by the presence or absence of short or long cycles does not identify these disturbances. In light of known clinical consequences of menstrual disturbances, these findings underscore the lack of reliability of normal menstrual intervals and self report to infer menstrual status.

We studied two groups of adult macaque monkeys to determine the time course of adult neurogenesis in the dentate gyrus of the hippocampus. In the first group, six adult monkeys (Macaca mulatta) received a single injection of the thymidine analog BrdU (75 mg/kg), which is incorporated into replicating DNA and serves as a marker for new cell birth. Brain tissue was collected 48 h, 2 wk, and 6 wk after BrdU injection to examine the initial stages of neurogenesis. Because mature neurons were not evident at 6 wk, we examined tissue collected over a longer time course in a second study. In this study, eight monkeys (Macaca fascicularis) who were subjects in a separate exercise study received 10 weekly injections of BrdU (75 mg/kg), and brain tissue was collected at 16 and 28 wk from the first injection. Based on the timing of expression of neuronal cell markers (βIII-tubulin, doublecortin, NeuN), the extent of dendritic arborization, and acquisition of mature cell body morphology, we show that granule cell maturation in the dentate gyrus of a nonhuman primate is protracted over a minimum of a 6-mo time period, more than 6 times longer than in rodents. The lengthened time course for new cell maturation in nonhuman primates may be appropriate for preservation of neural plasticity over their longer life span and is relevant to our understanding of antidepressant and other therapies that have been linked to neurogenesis in humans.immunohistochemistry | neuronal maturation | subgranular zone | granule cell layer | neuroprogenitor cell T he generation of new neurons has been shown to occur in the hippocampal dentate gyrus of mammals (1-3). The potential that adult hippocampal neurogenesis can be manipulated has inspired hope for treatments to slow or even repair brain damage from disease or injury. Adult hippocampal neurogenesis is thought to play a role in many brain processes including learning and memory (4-6), cognitive change with age (7), and disorders such as depression (8) and schizophrenia (9). One prominent theory suggests that the special properties (e.g., hyper-plasticity and functional naivety) of the maturing new neurons play an important role in hippocampal function (5, 9). Thus, understanding how new neurons mature in nonhuman primates is an important step for bridging our knowledge of adult neurogenesis in rodent models to a better understanding of this process in humans.A sequence of events in the maturation of adult born neurons has been established in rodents. Granule cells in the dentate gyrus of the hippocampus are the primary neuron type added. New granule cells divide from progenitor cells in the subgranular zone (SGZ), migrate approximately 2 cell body widths from the SGZ into the granule cell layer (GCL), and then extend axons and dendrites that make the appropriate connections and become functionally integrated into the hippocampal circuit (10). Electrophysiological maturation of new granule cells progresses over the period of 2-7 wk after cell division (10-14). These functional changes are accomp...

Ghrelin is directly involved with short-term regulation of energy balance. Although circulating levels of ghrelin are elevated in anorexia nervosa and reduced in obesity, the role of ghrelin in regulating long-term energy balance in healthy women has not been investigated. We examined the effects of a 3-month energy deficit-imposing diet and exercise intervention on circulating ghrelin in normal-weight, healthy women. Body composition, resting metabolic rate, and serum ghrelin were measured at pre-, mid-, and postintervention in controls (n = 7), who performed no exercise, and exercising women who remained weight stable (n = 5) or lost weight (n = 10). Exercise training occurred five times per week, and subjects were fed a specific diet. Ghrelin significantly increased over time (770 +/- 296 to 1322 +/- 664 pmol/liter) in the weight-loss group compared with the controls and the weight-stable group (P < 0.05). Changes in ghrelin were negatively correlated with changes in body weight (r = -0.61; P < 0.05). Body fat, body weight, and resting metabolic rate significantly decreased in the weight-loss group before the increase in ghrelin. These findings suggest that ghrelin responds in a compensatory manner to changes in energy homeostasis in healthy young women, and that ghrelin exhibits particular sensitivity to changes in body weight.

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Although the prevalence of individual/combined Triad conditions is concerning, our review demonstrates that additional research on the prevalence of the Triad using objective and/or self-report/field measures is necessary to more accurately describe the extent of the problem.