Maternal
bioactive substances, such as
hormones and
neuropeptides, are thought to be essential for
fetal development. Recently,
ghrelin, a
gastrointestinal peptide, has been shown to pass through the rat
placenta. The
ghrelin receptor,
growth hormone secretagogue receptor (GHS-R), has been shown to be expressed in the rat
fetal central nervous system, and plasma
ghrelin levels are related to
birth weight in the rodent and human. In the present study, we report a role of maternal
ghrelin in
mouse fetal brain development. When
ghrelin was administrated to
pregnant mice, pups exhibited suppression of exploratory behavior in an open-field (OF) test. Control pups, however, remained for longer periods of time in the center area, correlating with exploratory behavior. Basal
corticotropin-releasing hormone (CRH) plasma levels were greater in pups from ghrelin-treated dams, and did not change in response to acute restraint stress. Moreover, reduced
growth hormone secretagogue receptor and
neuropeptide Y mRNA expression was observed in the
hypothalamus at
postnatal day 3 and remained until 16 weeks of age. In addition, under physiological condition, increased maternal
ghrelin plasma levels following repeated restraint stress to the dam had effect on the increase in
fetal plasma
acyl ghrelin levels. These results suggest that maternal
ghrelin affect
fetal plasma
ghrelin levels and alters
endocrine systems and behaviors of offspring.
