title: The Relation Between Long-Term Synaptic Plasticity at Glutamatergic Synapses in the Amygdala and Fear Learning in Adult Heterozygous BDNF-Knockout Mice.
abstract: Brain-derived neurotrophic factor (BDNF) heterozygous knockout mice (BDNF+/- mice) show fear learning deficits from 3 months of age onwards. Here, we addressed the question how this learning deficit correlates with altered long-term potentiation (LTP) in the cortical synaptic input to the lateral amygdala (LA) and at downstream intra-amygdala synapses in BDNF+/- mice. Our results reveal that the fear learning deficit in BDNF+/- mice was not paralleled by a loss of LTP, neither at cortical inputs to the LA nor at downstream intra-amygdala glutamatergic synapses. As we did observe early fear memory (30 min after training) in BDNF+/- mice while long-term memory (24 h post-training) was absent, the stable LTP in cortico-LA and downstream synapses is in line with the intact acquisition of fear memories. Ex vivo recordings in acute slices of fear-conditioned wildtype (WT) mice revealed that fear learning induces long-lasting changes at cortico-LA synapses that occluded generation of LTP 4 and 24 h after training. Overall, our data show that the intact LTP in the tested amygdala circuits is consistent with intact acquisition of fear memories in both WT and BDNF+/- mice. In addition, the lack of learning-induced long-term changes at cortico-LA synapses in BDNF+/- mice parallels the observed deficit in fear memory consolidation.
authors.affiliation: Institut für Physiologie, Otto-von-Guericke-Universität, D-39120 Magdeburg, Germany.|Center for Behavioral Brain Sciences, Universitätsplatz 2, D-39106 Magdeburg, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Meis
authors.affiliation: Institut für Physiologie, Otto-von-Guericke-Universität, D-39120 Magdeburg, Germany.
authors.forename: T
authors.initials: T
authors.lastname: Endres
authors.affiliation: Institut für Physiologie, Otto-von-Guericke-Universität, D-39120 Magdeburg, Germany.|Center for Behavioral Brain Sciences, Universitätsplatz 2, D-39106 Magdeburg, Germany.
authors.forename: T
authors.initials: T
authors.lastname: Munsch
authors.affiliation: Institut für Physiologie, Otto-von-Guericke-Universität, D-39120 Magdeburg, Germany.|Center for Behavioral Brain Sciences, Universitätsplatz 2, D-39106 Magdeburg, Germany.
authors.forename: V
authors.initials: V
authors.lastname: Lessmann
mesh_terms: D000679:Amygdala / Q000166:cytology*; D000818:Animals; D019208:Brain-Derived Neurotrophic Factor / Q000172:deficiency* / Q000235:genetics; D002227:Carbazoles / Q000494:pharmacology; D002540:Cerebral Cortex / Q000502:physiology; D004558:Electric Stimulation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005071:Evoked Potentials / Q000235:genetics; D005239:Fear / Q000502:physiology*; D018756:GABA Antagonists / Q000494:pharmacology; D018698:Glutamic Acid / Q000378:metabolism*; D026121:Indole Alkaloids / Q000494:pharmacology; D007858:Learning / Q000502:physiology*; D017774:Long-Term Potentiation / Q000187:drug effects / Q000235:genetics*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009474:Neurons / Q000166:cytology / Q000187:drug effects; D018408:Patch-Clamp Techniques; D011724:Pyridazines / Q000494:pharmacology
chemical_list: D019208:Brain-Derived Neurotrophic Factor; D002227:Carbazoles; D004791:Enzyme Inhibitors; D018756:GABA Antagonists; D026121:Indole Alkaloids; D011724:Pyridazines; D018698:Glutamic Acid; C049985:staurosporine aglycone; C049853:gabazine