title: Absence of neurogenic response following robust predator-induced stress response.
abstract: Traumatic events contribute to a variety of neuropsychiatric disorders including post-traumatic stress disorder (PTSD). Identifying the neural mechanisms that affect the stress response may improve treatment for stress-related disorders. Neurogenesis, the production of neurons, occurs within the adult brain and disturbances in neurogenesis in the subgranular zone (SGZ) of the hippocampus have been linked to mood and anxiety disorders. Chronic stress models have mainly suggested correlations with stress reducing adult SGZ neurogenesis, whereas acute stress models and those with a naturalistic component that are also associated with long-lasting behavioral changes have produced inconsistent results. Therefore, the goal of the current study was to examine the effects of acute predator stress on adult neurogenesis. Predator stress involved a single 10-min unprotected rat to cat exposure that has previously been shown to produce contextual fear, hyperarousal, and anxiety-like behavior lasting at least 3weeks. As expected, predator stress produced a stress response as detected by elevated corticosterone (CORT) levels immediately after stress. Despite this robust stress response, there was no significant difference between stressed and handled control rats in the number of proliferating or surviving cells as assessed by a 5-bromo-2'-deoxyuridine-immunoreactive (BrdU-IR) labeling 2h or 4weeks post-stress throughout the rostro-caudal axis of the SGZ, respectively. Additionally, 90% of 4-week-old BrdU-IR cells in both conditions expressed NeuN, suggesting no change in cell fate with stress exposure. Overall, these data give caution to the notion that acute predator stress can alter the production or survival of adult-generated cells.
authors.affiliation: Department of Psychology, Memorial University of Newfoundland, St. John's, NL A1B 3X9, Canada.
authors.forename: Catherine
authors.initials: C
authors.lastname: Lau
authors.affiliation: Department of Psychology, Memorial University of Newfoundland, St. John's, NL A1B 3X9, Canada.
authors.forename: Mark
authors.initials: M
authors.lastname: Hebert
authors.affiliation: Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON K1N 6N5, Canada.
authors.forename: Marc A
authors.initials: MA
authors.lastname: Vani
authors.affiliation: Department of Psychology, Memorial University of Newfoundland, St. John's, NL A1B 3X9, Canada.
authors.forename: Sue
authors.initials: S
authors.lastname: Walling
authors.affiliation: Department of Neuroscience, Carleton University, Ottawa, ON K1S 5B6, Canada.
authors.forename: Shawn
authors.initials: S
authors.lastname: Hayley
authors.affiliation: Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON K1N 6N5, Canada.
authors.forename: Diane C
authors.initials: DC
authors.lastname: Lagace
authors.affiliation: Department of Psychology, Memorial University of Newfoundland, St. John's, NL A1B 3X9, Canada. Electronic address: jblundell@mun.ca.
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Blundell
mesh_terms: D053687:Adult Stem Cells / Q000473:pathology / Q000502:physiology; D000679:Amygdala / Q000473:pathology / Q000503:physiopathology; D000818:Animals; D002415:Cats; D002470:Cell Survival / Q000502:physiology; D003345:Corticosterone / Q000097:blood; D007033:Hypothalamus, Middle / Q000473:pathology / Q000503:physiopathology; D008297:Male; D058953:Neural Stem Cells / Q000473:pathology / Q000502:physiology; D055495:Neurogenesis / Q000502:physiology*; D009474:Neurons / Q000473:pathology / Q000502:physiology*; D011235:Predatory Behavior; D011897:Random Allocation; D020318:Rats, Long-Evans; D055153:Stem Cell Niche / Q000502:physiology; D013315:Stress, Psychological / Q000473:pathology / Q000503:physiopathology*
chemical_list: D003345:Corticosterone
keywords: BrdU; SGZ; adult hippocampal neurogenesis; post-traumatic stress disorder; predator stress