title: Hyper-responsivity to stress in rats is associated with a large increase in amygdala volume. A 7T MRI study.
abstract: Stress is known to precipitate psychiatric disorders in vulnerable people. Individual differences in the stress responsivity can dramatically affect the onset of these illnesses. Animal models of repeated stress represent valuable tools to identify region-specific volumetric changes in the brain. Here, using high resolution 7T MRI, we found that amygdala is the most significant parameter for distinction between F344 and SD rats known to have differential response to stress. A significant substantial increase (45%) was found in the amygdala volume of rats that do not habituate to the repeated stress procedure (F344 rats) compared to SD rats. This strain-specific effect of stress was evidenced by a significant strain-by-stress interaction. There were no significant strain differences in the volumes of hippocampi and prefrontal cortices though stress produces significant reductions of smaller amplitude in the medial prefrontal cortex (mPFC) (9% and 12%) and dorsal hippocampus (5% and 6%) in both strains. Our data further demonstrate the feasibility and relevance of high isotropic resolution structural ex vivo 7T MRI in the study of the brain effects of stress in small animals. Neuroimaging is a valuable tool to follow up brain volumetric reorganization during the stress response and could also be easily used to test pharmacological interventions to prevent the deleterious effects of stress.
authors.affiliation: Laboratoire de Physiopathologie des Maladies Psychiatriques, UMR_S 894 Inserm, Centre de Psychiatrie et Neurosciences, 75014 Paris, France; Centre hospitalier Sainte-Anne, Service Hospitalo-Universitaire, Paris, France; Université Paris Descartes, Sorbonne Paris Cité, Paris, France.
authors.forename: J
authors.initials: J
authors.lastname: Bourgin
authors.affiliation: Laboratoire de Physiopathologie des Maladies Psychiatriques, UMR_S 894 Inserm, Centre de Psychiatrie et Neurosciences, 75014 Paris, France; Université Paris Descartes, Sorbonne Paris Cité, Paris, France; CNRS UMR 8240, Laboratoire de Psychologie du développement et de l׳Education de l׳Enfant, Paris, France.
authors.forename: A
authors.initials: A
authors.lastname: Cachia
authors.affiliation: UNIRS, NeuroSpin, DSV/Institut d׳imagerie Biomédicale, CEA, Gif-sur-Yvette, France.
authors.forename: F
authors.initials: F
authors.lastname: Boumezbeur
authors.affiliation: UNIACT, NeuroSpin, DSV/Institut d׳imagerie Biomédicale, CEA, Gif-sur-Yvette, France.
authors.forename: B
authors.initials: B
authors.lastname: Djemaï
authors.affiliation: UNIACT, NeuroSpin, DSV/Institut d׳imagerie Biomédicale, CEA, Gif-sur-Yvette, France.
authors.forename: M
authors.initials: M
authors.lastname: Bottlaender
authors.affiliation: UNATI, NeuroSpin, DSV/Institut d׳imagerie Biomédicale, CEA, Gif-sur-Yvette, France.
authors.forename: E
authors.initials: E
authors.lastname: Duchesnay
authors.affiliation: UNIRS, NeuroSpin, DSV/Institut d׳imagerie Biomédicale, CEA, Gif-sur-Yvette, France.
authors.forename: S
authors.initials: S
authors.lastname: Mériaux
authors.affiliation: Laboratoire de Physiopathologie des Maladies Psychiatriques, UMR_S 894 Inserm, Centre de Psychiatrie et Neurosciences, 75014 Paris, France; Université Paris Descartes, Sorbonne Paris Cité, Paris, France. Electronic address: therese.jay@inserm.fr.
authors.forename: T M
authors.initials: TM
authors.lastname: Jay
mesh_terms: D000679:Amygdala / Q000473:pathology*; D000704:Analysis of Variance; D000818:Animals; D003345:Corticosterone / Q000097:blood; D004195:Disease Models, Animal; D004569:Electroencephalography; D006624:Hippocampus / Q000473:pathology; D008279:Magnetic Resonance Imaging; D008297:Male; D051381:Rats; D011916:Rats, Inbred F344; D017207:Rats, Sprague-Dawley; D013045:Species Specificity; D013315:Stress, Psychological / Q000097:blood / Q000473:pathology / Q000503:physiopathology*
chemical_list: D003345:Corticosterone
keywords: Cortico-limbic network; High-resolution structural MRI; Rat; Stress