Female puberty acceleration by male odour in mice: neural pathway and behavioural consequences.

In female mice, exposure to male chemosignals results in early puberty onset characterized by advanced vaginal opening and higher uterine weight. Evidence suggests that the male chemosignals responsible for acceleration of female puberty are androgen-dependent, but not all of the compounds that contribute to puberty acceleration have been identified. The male chemosignals are primarily detected and processed by the vomeronasal system including the vomeronasal organ, the accessory olfactory bulb and the medial amygdala.

Signals that link energy to reproduction: gastric fill, bulk intake, or caloric intake?

Reproductive processes are inhibited by deficits in the availability of metabolic fuels, and this inhibition increases the chances of survival during energetic challenges and optimizes reproductive success by delaying energetically costly processes until fuels become available. The mechanisms that link energy availability to reproduction are unknown, and thus, in this study we tested the hypothesis that estrous cycles are most sensitive to sensory signals from bulk intake and gastric fill as opposed to signals from caloric intake or the availability of intracellular oxidizable fuels. The caloric content of a standard laboratory chow diet was diluted by 25, 50, or 75% with the largely indigestible fiber, cellulose, and fed to food-deprived, female hamsters throughout day 2 of the estrous cycle (ovulation and estrous behavior normally occur on day 4).