2 research outputs found
Suppression of ovarian hormones in adolescent rats has no effect on anxiety-like behaviour or c-fos activation in the amygdala
Support was provided the British Society for Neuroendocrinology, Carnegie Trust for the Universities of Scotland and School of Psychology & Neuroscience, University of St Andrews.In humans, sex differences in mood disorders emerge during adolescence, with prevalence rates being consistently higher in females than males. It has been hypothesised that exposure to endogenous ovarian hormones during adolescence enhances the susceptibility of females to mood disorders from this stage of life onwards. However, experimental evidence in favour of this hypothesis is lacking. In the present study, we examined the longâterm effects of suppressing adolescent gonadal hormone levels in a group of female Listerâhooded rats via administration of a gonadotrophinâreleasing hormone antagonist (Antide; administered on postnatal day [PND] 28 and 42) compared to control females and males (n = 14 per group). We predicted that, in adulthood, Antideâtreated female rats would exhibit more maleâlike behaviour than control females in novel environments (elevatedâplus maze, open field and lightâdark box), in response to novel objects and novel social partners, and in an acoustic startle task. Progesterone and luteinising hormone assays (which were conducted on blood samples collected on PND 55/56 and 69/70) confirmed that the hypothalamicâpituitaryâgonadal axis was temporarily suppressed by Antide treatment. In addition, Antideâtreated females were found to exhibit a modest pubertal delay, as measured by vaginal opening, which was comparable in length to the pubertal delay that has been induced by adolescent exposure to alcohol or stress in previous studies of female rats. However, Antideâtreated females did not substantially differ from control females on any of the behavioural tests, despite the evidence for predicted sex differences in some measures. Following the acoustic startle response task, all subjects were culled and perfused, and câFos staining was conducted in the medial and basolateral amygdala, with the results showing no significant differences in cell counts between the groups. These findings suggest that ovarian hormone exposure during adolescence does not have longâterm effects on anxietyârelated responses in female rats.Publisher PDFPeer reviewe