title: Impaired fear extinction learning in adult heterozygous BDNF knock-out mice.
abstract: Brain-derived neurotrophic factor (BDNF) is a crucial regulator of neuroplasticity, which underlies learning and memory processes in different brain areas. To investigate the role of BDNF in the extinction of amygdala-dependent cued fear memories, we analyzed fear extinction learning in heterozygous BDNF knock-out mice, which possess a reduction of endogenous BDNF protein levels to ~50% of wild-type animals. Since BDNF expression has been shown to decline with aging of animals, we tested the performance in extinction learning of these mice at 2 months (young adults) and 7 months (older adults) of age. The present study shows that older adult heterozygous BDNF knock-out mice, which have a chronic 50% lack of BDNF, also possess a deficit in the acquisition of extinction memory, while extinction learning remains unaffected in young adult heterozygous BDNF knock-out mice. This deficit in extinction learning is accompanied by a reduction of BDNF protein in the hippocampus, amygdala and the prefrontal cortex.
authors.affiliation: Institute of Physiology, Medical Faculty, Otto-von-Guericke-University Magdeburg, Leipziger Str. 44, 39120 Magdeburg, Germany.
authors.forename: Laura
authors.initials: L
authors.lastname: Psotta
authors.forename: Volkmar
authors.initials: V
authors.lastname: Lessmann
authors.forename: Thomas
authors.initials: T
authors.lastname: Endres
mesh_terms: D000367:Age Factors; D000818:Animals; D001921:Brain / Q000378:metabolism; D019208:Brain-Derived Neurotrophic Factor / Q000235:genetics / Q000378:metabolism*; D003213:Conditioning, Psychological / Q000502:physiology*; D005108:Extinction, Psychological / Q000502:physiology*; D005239:Fear / Q000502:physiology*; D006579:Heterozygote; D051379:Mice; D018345:Mice, Knockout
chemical_list: D019208:Brain-Derived Neurotrophic Factor