Prostaglandin F2alpha-induced nest-building behaviour is associated with increased hypothalamic c-fos and c-jun mRNA...

Area of Science:

• Neuroendocrinology
• Reproductive Physiology
• Behavioral Science

Background:

• Prostaglandin F2alpha (PGF2alpha) induces luteolysis and nest-building behavior in pigs.
• Synthetic cloprostenol causes luteolysis but not nest-building behavior.
• Prostaglandin F2alpha receptors (FP) are present in key hypothalamic nuclei.

Purpose of the Study:

• To investigate the hypothalamic gene expression of c-fos and c-jun following PGF2alpha or cloprostenol administration.
• To determine if PGF2alpha's effect on nest-building behavior is mediated centrally.

Main Methods:

• Intramuscular injection of PGF2alpha, cloprostenol, or saline in female pigs.
• Behavioral recording and immediate post-injection tissue collection for analysis.
• In situ hybridization histochemistry to measure c-fos and c-jun mRNA expression in the hypothalamus and corpus lutea.

Main Results:

• PGF2alpha treatment significantly increased c-fos and c-jun mRNA in the paraventricular nucleus (PVN), supraoptic nucleus (SON), and supraoptic nucleus pars-medialis (SOD) compared to controls.
• Both PGF2alpha and cloprostenol increased c-fos and c-jun mRNA in the corpus lutea.
• Only PGF2alpha induced nest-building behavior.

Conclusions:

• PGF2alpha, but not cloprostenol, acts centrally to induce nest-building behavior in pigs.
• The findings suggest PGF2alpha or a metabolite crosses the blood-brain barrier to activate hypothalamic FP receptors.
• This central action mediates the behavioral response associated with prostaglandin administration.