Role of the posterodorsal medial amygdala in predator odour stress‐induced puberty delay in female rats

Xiao Feng Li, Daniel A. Adekunbi, Hussah M. Alobaid, Shengyun Li, Michel Pilot, Stafford L. Lightman, Kevin T. O'Byrne*

*Corresponding author for this work

Research output: Contribution to journalArticle (Academic Journal)

162 Downloads (Pure)

Abstract

Puberty onset is influenced by various factors, including psychosocial stress. The present study investigated cat‐odour stress on puberty onset and oestrous cyclicity in rats. Female weanling rats were exposed to either soiled cat litter or fresh unused litter for 10 consecutive days. Following vaginal opening (VO), rats were smeared for 14 days to determine oestrous cyclicity. Anxiety‐like behaviour was assessed using standard anxiety tests. Brains were collected to determine corticotrophin‐releasing factor (CRF), CRF receptor 1 (CRF‐R1) and CRF receptor 2 (CRF‐R2) mRNA in the paraventricular nucleus (PVN), as well as the central nucleus of the amygdala (CEA) and the medial nucleus of the amygdala (MEA). Cat odour delayed VO and first oestrus, disrupted oestrous cycles and caused anxiogenic responses. Cat odour elicited increased CRF mRNA expression in the PVN but not in the CeA. CRF‐R1 and CRF‐R2 mRNA levels in the PVN and CeA were unaffected by cat odour; however, CRF‐R1 mRNA levels were decreased in the MeA. The role of CRF signalling in the MeA, particularly its posterodorsal subnucleus (MePD), with respect to pubertal timing was directly examined by unilateral intra‐MePD administration of CRF (0.2 nmol day‐1 for 14 days) via an osmotic mini‐pump from postnatal day 24 and was shown to delay VO and first oestrus. These data suggest that CRF signalling in the MePD may be associated with predator odour‐induced puberty delay.
Original languageEnglish
Article numbere12719
Number of pages12
JournalJournal of Neuroendocrinology
Volume31
Issue number6
Early online date29 Apr 2019
DOIs
Publication statusPublished - 1 Jun 2019

Keywords

  • amygdala
  • CRF
  • predator
  • puberty
  • stress

Fingerprint Dive into the research topics of 'Role of the posterodorsal medial amygdala in predator odour stress‐induced puberty delay in female rats'. Together they form a unique fingerprint.

  • Cite this