title: Infant cognitive training preshapes learning-relevant prefrontal circuits for adult learning: learning-induced tagging of dendritic spines.
abstract: Work in various animal models has demonstrated that cognitive training in infancy has a greater effect on adult cognitive performance than pretraining in adulthood. Since the underlying synaptic mechanisms are unclear, the aim of this study was to test the working hypothesis that associative training "preshapes" synaptic circuits in the developing infant brain and thereby improves learning in adulthood. Using a two-way active avoidance (TWA) paradigm, we found that avoidance training during infancy, even though the infant rats were not capable to learn a successful avoidance strategy, improves avoidance learning in adulthood. On the neuroanatomical level we show here for the first time that infant TWA training in the ventromedial prefrontal cortex suppresses developmental spine formation. In contrast in the lateral orbitofrontal cortex, developmental spine pruning is suppressed, possibly by "tagging" activated synapses, which thereby are protected from being eliminated. Moreover, we demonstrate that infant TWA training alters learning-induced synaptic plasticity in the adult brain. The synaptic and dendritic changes correlate with specific behavioral parameters. Taken together, these results support the working hypothesis that infant cognitive training interferes with developmental reorganization and maturation of dendritic spines and thereby "optimizes" prefrontal neuronal circuits for adult learning.
authors.affiliation: Project Group: Epigenetics and Structural Plasticity, Center For Behavioral Brain Science (CBBS), Magdeburg, Germany and.
authors.forename: Joerg
authors.initials: J
authors.lastname: Bock
authors.affiliation: Institute for Biology, Human Biology, University of Leipzig, Leipzig 04103, Germany.
authors.forename: Gerd
authors.initials: G
authors.lastname: Poeggel
authors.affiliation: Department of Zoology/Developmental Neurobiology, Otto von Guericke University, Magdeburg, Germany Center For Behavioral Brain Science (CBBS), Magdeburg, Germany and.
authors.forename: Michael
authors.initials: M
authors.lastname: Gruss
authors.affiliation: Institute for Biology, Human Biology, University of Leipzig, Leipzig 04103, Germany.
authors.forename: Katharina
authors.initials: K
authors.lastname: Wingenfeld
authors.affiliation: Department of Zoology/Developmental Neurobiology, Otto von Guericke University, Magdeburg, Germany Center For Behavioral Brain Science (CBBS), Magdeburg, Germany and.
authors.forename: Katharina
authors.initials: K
authors.lastname: Braun
mesh_terms: D000367:Age Factors; D000704:Analysis of Variance; D000818:Animals; D000831:Animals, Newborn; D001362:Avoidance Learning / Q000502:physiology*; D049229:Dendritic Spines / Q000502:physiology*; D005260:Female; D016014:Linear Models; D008297:Male; D009473:Neuronal Plasticity / Q000502:physiology*; D009474:Neurons / Q000166:cytology*; D017397:Prefrontal Cortex / Q000166:cytology* / Q000254:growth & development*; D011247:Pregnancy; D051381:Rats; D016622:Silver Staining
keywords: cortical development; learning; memory; synaptic plasticity; synaptic tagging