Amygdala-dependent fear conditioning in humans is modulated by the BDNFval66met polymorphism.
The brain-derived neurotrophic factor (BDNF) is critically involved in neuroplasticity, as well as the acquisition, consolidation, and retention of hippocampal- and amygdala-dependent learning. A common functional A-->G single nucleotide polymorphism (BDNFval66met) in the prodomain of the human BDNF gene is associated with abnormal intracellular trafficking and reduced activity-dependent BDNF release. We studied the effect of BDNFval66met in an aversive differential fear conditioning, and a delayed extinction paradigm in 57 healthy participants. Pictures of male faces were used as stimuli and fear learning was quantified by fear potentiated startle (FPS) and skin conductance responses (SCR). Aware BDNF met-carriers show a deficit in amygdala-dependent fear conditioning as indicated by an absence of FPS responses in the last acquisition block. This deficit was maintained in the first block of extinction. No genotype differences were found in conditioned SCR discrimination. These data provide evidence for the involvement of BDNF signaling in human amygdala-dependent learning. We suggest that the BDNF met-allele may have a protective effect for the development of affective pathologies that may be mediated via reduced synaptic plasticity induced by negative experience.
Department of Clinical Neuroscience, Psychology Section, Stockholm Brain Institute, Karolinska Institutet.
Tina B
TB
Lonsdorf
Earnst-Moritz-Arndt University of Greifswald.
Almut I
AI
Weike
Department of Clinical Neuroscience, Psychology Section, Stockholm Brain Institute, Karolinska Institutet.
Armita
A
Golkar
Center for Molecular Medicine and Surgery, Neurogenetics Section, Karolinska Institutet.
Martin
M
Schalling
Earnst-Moritz-Arndt University of Greifswald.
Alfons O
AO
Hamm
Department of Clinical Neuroscience, Psychology Section, Stockholm Brain Institute, Karolinska Institutet.
Arne
A
Öhman
D000161:Acoustic Stimulation / Q000009:adverse effects; D000679:Amygdala / Q000502:physiology*; D000704:Analysis of Variance; D001362:Avoidance Learning / Q000502:physiology; D019208:Brain-Derived Neurotrophic Factor / Q000235:genetics*; D003214:Conditioning, Classical / Q000502:physiology*; D004576:Electromyography; D005108:Extinction, Psychological / Q000502:physiology; D005239:Fear; D005260:Female; D005712:Galvanic Skin Response / Q000235:genetics; D005838:Genotype; D006801:Humans; D008297:Male; D008715:Methionine / Q000235:genetics*; D010775:Photic Stimulation / Q000379:methods; D011110:Polymorphism, Genetic / Q000235:genetics*; D013216:Reflex, Startle / Q000235:genetics; D013334:Students; D014495:Universities; D014633:Valine / Q000235:genetics*
D019208:Brain-Derived Neurotrophic Factor; D008715:Methionine; D014633:Valine