Browse by author
Lookup NU author(s): Professor Colin Ingram
Full text for this publication is not currently held within this repository. Alternative links are provided below where available.
Intracerebroventricular administration of oxytocin reduces anxiety behavior and hypothalamo-pituitary-adrenal (HPA) responses to stress in female rats. Similar changes are seen in late-pregnant rats, and oxytocin-sensitive pathways may mediate these effects. This study investigated anxiety behavior and stress responses using a gonadal steroid model of late pregnancy, which is known to increase endogenous oxytocin expression. Compared with continuous progesterone treatment, 3-d withdrawal of progesterone after 11-d treatment of ovariectomized rats with estradiol and progesterone resulted in increased binding of the oxytocin receptor ligand [125I]d(CH2)5[Tyr(Me)2,Thr 4,Tyr-NH29]ornithine vasotocin in selective forebrain regions, including the ventrolateral septum and ventromedial hypothalamus. Behavior in the elevated plus-maze indicated that progesterone withdrawal had an anxiolytic effect, and this was associated with lower levels of c-fos mRNA expression in the ventral hippocampus, an area previously shown to be sensitive to oxytocin. In other groups of animals, the plasma corticosterone response to a psychological stress (10 min of 114 dB white noise) was significantly attenuated by this steroid manipulation. Furthermore, simultaneous infusion of the selective oxytocin receptor antagonist desGlyNH2,d(CH2)5[Tyr(Me)2,Thr 4]OVT during the period of progesterone withdrawal reversed this attenuation of noise-induced HPA activation, indicating a role for endogenous oxytocin in this effect. Thus, mimicking the steroid profile of late pregnancy leads to a reduction in anxiety behavior and attenuates HPA activity induced by mild stress. These effects appear to be mediated through the involvement of central oxytocin neurotransmission. Copyright © 2006 by The Endocrine Society.
Author(s): Windle RJ, Gamble LE, Kershaw YM, Wood SA, Lightman SL, Ingram CD
Publication type: Article
Publication status: Published
ISSN (print): 0013-7227
ISSN (electronic): 1945-7170
Publisher: The Endocrine Society
PubMed id: 16439458
Altmetrics provided by Altmetric