Gene expression in the forebrain of dexamethasone-treated pigs: effects on stress neuropeptides in the hypothalamus and hippocampus and glutamate receptor subunits in the hippocampus

Gene expression studies advance our understanding of the effects of stress and glucocorticoids on brain function and give a new direction to animal welfare research. In this context, the presence of messenger RNA s (m RNA s) for corticotrophin releasing hormone (CRH) and vasopressin (VP) in the porcine hypothalamus has recently been documented. This study investigated the expression of CRH, VP and ionotropic glutamate receptor (iGluR) subunit m RNA s in the brains of pigs treated with the synthetic glucocorticoid dexamethasone (Dex; 5 mg kg(-1)i.v.). In the hypothalamus, VP, but not CRH, m RNA was reduced 3 hours after Dex. In the hippocampus, expression of m RNA s for some iGluR subunits appeared to be differentially regulated 6 hours after Dex. In addition, CRH message was detected in the hippocampus and significantly upregulated in the CA1 region 3 hours after Dex. The relevance of these findings to stress neurobiology of the growing pig is discussed.