Effects of early maternal separation on subsequent reproductive and behavioral outcomes in male rats.

To investigate effects of maternal separation on reproductive and behavioral outcomes, male Wistar rats were separated from their mothers daily for 3 hr (maternal separation; MS) or 0 hr (control) from postnatal day (PND) 1 to 14. Timing of puberty, reproductive parameters, hormone levels, and aggressive behaviors in juvenile and adult rats were examined. Contrary to expectations, there was no effect of maternal separation on any measure of aggression.

Differential effects of short- and long-term early maternal separation on subsequent maternal behavior in rats.

Female Sprague-Dawley pups were separated from mothers every other day for 8 hr (long-term separation/LTS), 4 hr (short-term separation/STS), or 0 hr (no separation/NS) from postnatal day 2-20. In adulthood, they were mated and tested for maternal behaviors during two lactations. It was expected that females separated from mothers as pups would show deficits in maternal behavior as adults.

Emergency contraception and RU-486 (mifepristone): do bioethical discussions improve learning and retention?

To systematically investigate whether the inclusion of a bioethical discussion improves the learning and retention of biological content, students in two sections of an introductory zoology class were taught the biology behind emergency contraception and RU-486. Students in one section of the course participated in a bioethical discussion, whereas students in the other section participated in a content-only discussion. Pre- and postsurveys, response paragraphs, and a final exam were collected and used to examine the learning and retention of content knowledge.

Effects of dehydroepiandrosterone sulfate and progesterone on spatial learning and memory in young and aged mice.

Young (2-4 months) and aged (14-16 months) male Swiss-Webster albino mice (n = 7 per group) were subcutaneously injected with 20 mg/kg/day dehydroepiandrosterone sulfate (DHEAS), progesterone (P), DHEAS + P, or vehicle control and trained over a 5-day period in a Morris water maze. The subjects were tested 48 hr after training for memory recall as measured by latencies to locate the hidden platform, and trunk blood was collected immediately thereafter. As expected, latency to platform decreased for all groups over the 6 testing days, with aged mice taking longer to reach platform than did young mice.

Dibromoacetic acid, a commonly occurring water disinfection by-product, does not affect follicular populations in neonatal rats.

To investigate whether the mechanism of dibromoacetic acid (DBA) toxicity involves disruption of primordial germ cell migration and/or follicular formation, pregnant and lactating female Sprague-Dawley rats were gavaged daily with 0, 1, 5, or 50 mg DBA/kg body weight beginning on gestation day 17 and continuing through postnatal day 7. Reproductive parameters in 4 groups (n = 10 per group) of female neonatal rats exposed to DBA were examined. Maternal weight, litter size, and gender ratio did not differ across treatment groups, and major organ weights (spleen, liver, kidneys, uterus, and ovary) did not differ from control.