Methyl donor supplementation alters serum leptin levels and increases appetite but not body weight in cross-fostered male Syrian hamster offspring (Mesocricetus auratus).

A pregnant hamster's exposure to changes in environmental factors, such as light, temperature and nutrition, may influence behavioural and physiological changes in offspring. In this study, dietary methyl donor supplementation was employed to examine the role of maternal diet on appetite, body weight, serum leptin levels and locomotor activity in male Syrian hamster offspring. Dams were fed a standard control (SC) or methyl donor-supplemented (MDSD) diet through pregnancy and lactation.

Brain corticotropin-releasing hormone (CRH) circuits in the developing rat: effect of maternal deprivation.

Early in life, there is a delicate and critical balance aimed to maintain low hormone responses derived from the stress responsive hypothalamic-pituitary-adrenal axis (HPA). However, in the infant rat hypothalamic corticotrophin-releasing hormone (CRH) stress responses to environmental events are clearly seen even though other elements of the HPA axis may have limited responses. In view of the role of CRH in mediating behavior associated with stress and anxiety, we considered the ontogeny and the effects of prolonged maternal deprivation (DEP) in brain areas that express CRH-related molecules outside the hypothalamus.

Development of rhythmic melatonin secretion from the pineal gland of embryonic mummichog (Fundulus heteroclitus).

The pineal gland of vertebrates produces and secretes the hormone melatonin in response to changes in the light-dark cycle, with high production at night and low production during the day. Melatonin is thought to play an important role in synchronizing daily and/or seasonal physiological, behavioral, and developmental rhythms in vertebrates. In this study, the functional development of the pineal melatonin-generating system was examined in the mummichog, Fundulus heteroclitus, an euryhaline teleost.

Differential expression of c-fos and tyrosine hydroxylase mRNA in the adrenal gland of the infant rat: evidence for an adrenal hyporesponsive period.

Rats exhibit a stress hyporesponsive period from postnatal day (PND) 4-14 in which the neonate displays a minimal corticosterone response to stress. We used the maternal deprivation model to test whether this adrenocortical hyporesponsiveness to stress results from a decrease in adrenal sensitivity to ACTH. Neonates (PND 6, 9, and 12) were injected ip with dexamethasone to block endogenous ACTH release, and 4 h later injected with graded doses of ACTH and killed.