Nursing has important physiological and psychological consequences on mothers during the postpartum period. Tuberoinfundibular peptide of 39 residues (TIP39) may contribute to its effects on prolactin release and maternal motivation. Since TIP39-containing fibers and the receptor for TIP39, the parathyroid hormone 2 receptor (PTH2 receptor) are abundant in the arcuate nucleus and the medial pre...

A new mechanism for puberty is proposed . Puberty appears to result from the interaction of two physiologic oscillators within the hypothalamus : the arcuate nucleus, which produces the gonadotropin-releasing hormone, and the suprachiasmatic nucleus, which is a master oscillator that regulates many circadian rhythms . Puberty results when the frequency of the arcuate nucleus has slowed sufficie...

In this study, we examined the effects of restricted feeding and of central administration of an orexigenic ghrelin agonist GHRP-6 on peptide mRNA expression in the hypothalamus. We compared rats fed ad libitum with rats that were allowed food for only 2?h every day, and treated with a continuous chronic i.c.v. infusion of GHRP-6 or vehicle. Ad libitum fed rats exposed to GHRP-6 increased their...

The endogenous peptides beta-endorphin (beta-END) and neuropeptide Y (NPY) have been implicated in regulating sexual receptivity. Both beta-END and NPY systems are activated by estrogen and inhibit female sexual receptivity. The initial estrogen-induced sexual nonreceptivity is correlated with the activation and internalization of mu-opioid receptors (MORs), in the medial preoptic nucleus (MPN)...