The Relation Between Long-Term Synaptic Plasticity at Glutamatergic Synapses in the Amygdala and Fear Learning in Adult Heterozygous BDNF-Knockout Mice. (10th February 2017)

• Record Type: Journal Article
• Authors: Meis, S; Endres, T; Munsch, T; Lessmann, V
• Is Part Of: Cerebral cortex. Volume 28:Number 4(2018)
• Page Start: 1195
• Page End: 1208
• Publication Date: 2017-02-10
• Subjects: amygdala -- BDNF -- fear conditioning -- field recording -- long-term potentiation; Cerebral cortex -- Periodicals; Brain -- Periodicals; 612.825
• DOI: 10.1093/cercor/bhx032
• Languages: English
• ISSNs: 1047-3211

Abstract

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.