# Corticosteroid-receptor mediated mechanisms in the amygdala regulate anxiety and colo



## eric (Jul 8, 1999)

Corticosteroid-receptor mediated mechanisms in the amygdala regulate anxiety and colonic sensitivity.1: Am J Physiol Gastrointest Liver Physiol. 2007 Mar 8; [Epub ahead of print]Corticosteroid-receptor mediated mechanisms in the amygdala regulate anxiety and colonic sensitivity.Myers B, Greenwood-Van Meerveld B. Oklahoma Center for Neuroscience, VA Medical Center, Oklhaoma City, Oklahoma, United States; University of Oklahoma Health Sciences Center, United States.Our previous studies have shown that stereotaxic implantation of corticosterone (CORT) onto the central amygdaloid nucleus (CeA) increases both anxiety and colonic sensitivity. The goal of this study was to examine the relative importance of amygdaloid glucocorticoid (GR) and mineralocorticoid (MR) receptor-mediated mechanisms in the induction of anxiety and colonic hypersensitivity. In male Fischer-344 rats, CORT or cholesterol micropellets were stereotaxically implanted bilaterally at the dorsal boundary of the CeA either alone or in combination with a GR antagonist, mifepristone, or a MR antagonist, spironolactone. Anxiety was assessed on the elevated plus maze and quantified as the percentage of time spent in open arm exploration. Colonic sensitivity was measured by recording a visceromotor response (VMR), the number of abdominal muscle contractions in response to colorectal distension (CRD). In CORT-implanted rats there was a significant reduction in the percentage of time spent in the open arms of the elevated plus maze compared to cholesterol controls, indicating increased anxiety. Furthermore, colonic hypersensitivity was observed in response to CRD when compared to rats with cholesterol implants. In rats with CORT implants combined with either a GR or MR antagonist, there was a significant inhibition of anxiety colonic hypersensitivity. Our data suggest that both GR and MR play a critical role in CORT-induced anxiety and colonic hypersensitivity. Key words: Corticosterone, Hypothalamic-Pituitary-Adrenal Axis, Irritable Bowel Syndrome.PMID: 17347454


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