Early adverse experience alters dendritic spine density and gene expression in prefrontal cortex and hippocampus in lambs

• Published in: Psychoneuroendocrinology 2013-07, Vol.38 (7), p.1112-1121
• Main Authors: Coulon, Marjorie, Wellman, Cara L, Marjara, Inderjit S, Janczak, Andrew M, Zanella, Adroaldo J
• Format: Article
• Language: English
• Subjects: Animals; Animals, Newborn; Behavioral psychophysiology; Biological and medical sciences; Computer Science; Dendritic Spines - physiology; Endocrinology & Metabolism; Female; Fundamental and applied biological sciences. Psychology; Gene Expression; Glucocorticoids; Hippocampus; Hippocampus - metabolism; Hippocampus - physiopathology; Hormones and behavior; Humanities and Social Sciences; Lambs; Life Sciences; Male; Prefrontal cortex; Prefrontal Cortex - metabolism; Prefrontal Cortex - physiopathology; Pregnancy; Prenatal Exposure Delayed Effects - genetics; Prenatal Exposure Delayed Effects - metabolism; Prenatal Exposure Delayed Effects - physiopathology; Prenatal stress; Psychiatry; Psychology. Psychoanalysis. Psychiatry; Psychology. Psychophysiology; Pyramidal Cells - physiology; Sheep; Spine density and morphology; Stress, Psychological - genetics; Stress, Psychological - metabolism; Stress, Psychological - physiopathology
• ISSN: 0306-4530; 1873-3360
• DOI: 10.1016/j.psyneuen.2012.10.018

Summary In the laboratory, prenatal stress produces alterations in the structure and function of corticolimbic neurons. Here we report changes in gene expression and corticolimbic dendritic spine morphology in the offspring of pregnant ewes subjected to aversive interactions with human handlers during the last five weeks of pregnancy (AVS) compared to control dams that received gentle handling (GEN). AVS lambs had higher spine density on pyramidal neurons in area CA1 of the hippocampus and in medial prefrontal cortex compared to GEN lambs, as well as a lower ratio of mushroom spines to stubby and thin spines in area CA1. Expression of genes involved in brain development and spine morphogenesis was decreased in hippocampus and prefrontal cortex in AVS compared to GEN lambs. This study is the first demonstration that an ecologically relevant aversive experience in a field setting alters neuronal structure similarly to previous reports from laboratory settings and that even for animals domesticated over 12,000 years ago, an apparently mild stressor, resulting from human–animal interactions, can have similarly profound impacts on corticolimbic morphology.