title: A novel model of early experiences involving neonatal learning of a T-maze using maternal contact as a reward or its denial as an event of mild emotional adversity.
abstract: We developed a novel animal model of early life experiences in which rat pups are trained during postnatal days (PND) 10-13 in a T-maze with maternal contact as a reward (RER group) or its denial (DER group) as a mildly aversive event. Both groups of animals learn the T-maze, albeit the RER do so more efficiently. Training results in activation of the basal ganglia in the RER and of the hippocampus and prefrontal cortex in the DER. Moreover, on PND10 DER training leads to increased corticosterone levels and activation of the amygdala. In adulthood, male DER animals show better mnemonic abilities in the Morris water maze while the RER exhibit enhanced fear memory. Furthermore, DER animals have a hypofunctioning serotonergic system and express depressive-like behavior and increased aggression. However, they have increased hippocampal glucocorticoid receptors, indicative of efficient hypothalamic-pituitary-adrenal axis function, and an adaptive pattern of stress-induced corticosterone response. The DER experience with its relatively negative emotional valence results in a complex behavioral phenotype, which cannot be considered simply as adaptive or maladaptive.
authors.affiliation: Biology-Biochemistry Lab, School of Health Sciences, National and Kapodistrian University of Athens, 123 Papadiamantopoulou Str., Athens, 11527, Greece.
authors.forename: Antonios
authors.initials: A
authors.lastname: Stamatakis
authors.forename: Anastasia
authors.initials: A
authors.lastname: Diamantopoulou
authors.forename: Theofanis
authors.initials: T
authors.lastname: Panagiotaropoulos
authors.forename: Androniki
authors.initials: A
authors.lastname: Raftogianni
authors.forename: Fotini
authors.initials: F
authors.lastname: Stylianopoulou
mesh_terms: D000223:Adaptation, Psychological / Q000502:physiology*; D000818:Animals; D000831:Animals, Newborn / Q000254:growth & development / Q000502:physiology*; D001522:Behavior, Animal / Q000502:physiology*; D001921:Brain / Q000254:growth & development / Q000502:physiology* / Q000503:physiopathology; D008425:Maternal Behavior / Q000502:physiology*; D018782:Maze Learning / Q000502:physiology*; D023421:Models, Animal; D051381:Rats; D012201:Reward
keywords: HPA axis; amygdala; corticosterone; hippocampus; latent learning; pCREB; prefrontal cortex; proteomics; rat; serotonin