Abstract
AbstractIn the wild, animals face a highly variable world full of predators. Most predator attacks are unsuccessful, and the prey survives. According to the conventional perspective, the fear responses elicited by predators are acute and transient in nature. However, the long-term, non-lethal effects of predator exposure on prey behavioral stress sequelae, such as anxiety and post-traumatic symptoms, remain poorly understood. Most experiments on animal models of anxiety-related behavior or post-traumatic stress disorder have been carried out using commercial strains of rats and mice. A fundamental question is whether laboratory rodents appropriately express the behavioral responses of wild species in their natural environment; in other words, whether behavioral responses to stress observed in the laboratory can be generalized to natural behavior. To further elucidate the relative contributions of the natural selection pressures influences, this study investigated the bio-behavioral and morphological effects of auditory predator cues (owl territorial calls) in males and females of three wild rodent species in a laboratory set-up: Acomys cahirinus; Gerbillus henleyi; and Gerbillus gerbillus. Our results indicate that owl territorial calls elicited not only “fight or flight” behavioral responses but caused PTSD-like behavioral responses in wild rodents that have never encountered owls in nature and could cause, in some individuals, enduring physiological and morphological responses that parallel those seen in laboratory rodents or traumatized people. In all rodent species, the PTSD phenotype was characterized by a blunting of fecal cortisol metabolite response early after exposure and by a lower hypothalamic orexin-A level and lower total dendritic length and number in the dentate gyrus granule cells eight days after predator exposure. Phenotypically, this refers to a significant functional impairment that could affect reproduction and survival and thus fitness and population dynamics.
Publisher
Springer Science and Business Media LLC
Subject
Cellular and Molecular Neuroscience,Psychiatry and Mental health,Molecular Biology
Reference74 articles.
1. American Psychiatric Association: Diagnostic and Statistical Manual of Mental Disorders (5th Edition) - DSM-5. 5 ed ed. Washington, DC,: American Psychiatric Association (2013).
2. Brown JS, Kotler BP, Bouskila A. Ecology of fear: Foraging games between predators and prey with pulsed resources. Annales Zoologici Fennici. 2001;38:71–87.
3. Houston A, McNamara J, Hutchinson J. General results concerning the trade-off between gaining energy and avoiding predation. Philos Trans R Soc Lond. 1993;341:375–97.
4. Hugie DM. The waiting game: a “battle of waits” between predator and prey. Behav Ecol. 2003;14:807–17.
5. Katz MW, Abramsky Z, Kotler BP, Rosenzweig ML, Alteshtein O, Vasserman G. Optimal foraging of little egrets and their prey in a foraging game in a patchy environment. Am Naturalist. 2013;181:381–95.