Social and Behavioral Sciences Commons^™

Orexins Mediate Sex Differences In The Stress Response And In Cognitive Flexibility, Laura A. Grafe, Amanda Cornfeld, Sandra Luz, Rita Valentino, Seema Bhatnagar

Psychology Faculty Research and Scholarship

BACKGROUND: Women are twice as likely as men to suffer from stress-related psychiatric disorders. However, the biological basis of these sex differences is poorly understood. Orexins are altered in anxious and depressed patients. Using a rat model of repeated stress, we asked whether orexins contribute to sex differences in outcomes relevant to stress-related psychiatric diseases.

METHODS: Behavioral, neural, and endocrinal habituation to repeated restraint stress and subsequent cognitive flexibility was examined in adult male and female rats. In parallel, orexin expression and activation was determined in both sexes, and chromatin immunoprecipitation was used to determine transcription factors acting at the …

Orexin 2 Receptor Regulation Of The Hypothalamic–Pituitary–Adrenal (Hpa) Response To Acute And Repeated Stress, Laura A. Grafe, Darrell Eacret, Sandra Luz, Anthony L. Gotter, John J. Renger, Chris J. Winrow, Seema Bhatnagar

Psychology Faculty Research and Scholarship

Orexins are hypothalamic neuropeptides that have a documented role in mediating the acute stress response. However, their role in habituation to repeated stress, and the role of orexin receptors (OX₁R and OX₂R) in the stress response, has yet to be defined. Orexin neuronal activation and levels in the cerebrospinal fluid were found to be stimulated with acute restraint, but were significantly reduced by day five of repeated restraint. As certain disease states such as panic disorder are associated with increased central orexin levels and failure to habituate to repeated stress, the effect of activating orexin signaling …