Brain-derived neurotrophic factor: linking fear learning to memory consolidation.

Brain-derived neurotrophic factor (BDNF), a member of the neurotrophin family, plays an important role in synaptic plasticity. In this issue of Molecular Pharmacology, Ou and Gean (p. 350) thoroughly describe the molecular cascade by which fear learning leads to an increase in BDNF expression in the lateral amygdala (LA). Calcium influx through N-methyl-D-aspartate receptors and L-type voltage-dependent calcium channels, which occurs in the LA during fear conditioning, activates protein kinase A and Ca2+/calmodulin-dependent protein kinase IV. Each induces phosphorylation of cAMP response element-binding protein, which binds to the BDNF promoter, leading to BDNF expression in the LA, and contributes to fear memory consolidation.