title: Critical features of acute stress-induced cross-sensitization identified through the hypothalamic-pituitary-adrenal axis output.
abstract: Stress-induced sensitization represents a process whereby prior exposure to severe stressors leaves animals or humans in a hyper-responsive state to further stressors. Indeed, this phenomenon is assumed to be the basis of certain stress-associated pathologies, including post-traumatic stress disorder and psychosis. One biological system particularly prone to sensitization is the hypothalamic-pituitary-adrenal (HPA) axis, the prototypic stress system. It is well established that under certain conditions, prior exposure of animals to acute and chronic (triggering) stressors enhances HPA responses to novel (heterotypic) stressors on subsequent days (e.g. raised plasma ACTH and corticosterone levels). However, such changes remain somewhat controversial and thus, the present study aimed to identify the critical characteristics of the triggering and challenging stressors that affect acute stress-induced HPA cross-sensitization in adult rats. We found that HPA cross-sensitization is markedly influenced by the intensity of the triggering stressor, whereas the length of exposure mainly affects its persistence. Importantly, HPA sensitization is more evident with mild than strong challenging stressors, and it may remain unnoticed if exposure to the challenging stressor is prolonged beyond 15 min. We speculate that heterotypic HPA sensitization might have developed to optimize biologically adaptive responses to further brief stressors.
authors: Institut de Neurociències, Universitat Autònoma de Barcelona, Cerdanyola del Vallès 08193, Barcelona, Spain.|Animal Physiology Unit, School of Biosciences, Universitat Autònoma de Barcelona, Cerdanyola del Vallès 08193, Barcelona, Spain.|Psychobiology Unit, School of Psychology, Universitat Autònoma de Barcelona, Cerdanyola del Vallès 08193, Barcelona, Spain.
authors: Xavier
authors: X
authors: Belda
authors: Institut de Neurociències, Universitat Autònoma de Barcelona, Cerdanyola del Vallès 08193, Barcelona, Spain.|Psychobiology Unit, School of Psychology, Universitat Autònoma de Barcelona, Cerdanyola del Vallès 08193, Barcelona, Spain.|Red de Trastornos Adictivos (ISCIII) Universitat Autònoma de Barcelona, Cerdanyola del Vallès 08193, Barcelona, Spain.
authors: Roser
authors: R
authors: Nadal
authors: Institut de Neurociències, Universitat Autònoma de Barcelona, Cerdanyola del Vallès 08193, Barcelona, Spain.|Animal Physiology Unit, School of Biosciences, Universitat Autònoma de Barcelona, Cerdanyola del Vallès 08193, Barcelona, Spain.|Psychobiology Unit, School of Psychology, Universitat Autònoma de Barcelona, Cerdanyola del Vallès 08193, Barcelona, Spain.
authors: Antonio
authors: A
authors: Armario
mesh_terms: D000324:Adrenocorticotropic Hormone / Q000097:blood; D000818:Animals; D059333:Central Nervous System Sensitization; D003345:Corticosterone / Q000097:blood; D007030:Hypothalamo-Hypophyseal System / Q000502:physiology*; D008297:Male; D010913:Pituitary-Adrenal System / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013315:Stress, Psychological / Q000378:metabolism*
chemical_list: D000324:Adrenocorticotropic Hormone; D003345:Corticosterone