An SNP (G196A, Val66Met) in the gene that encodes BDNF in humans significantly impairs BDNF's intracellular trafficking and activity-dependent release56. It is also associated with reduced hippocampal volume57. Mice that express the Met66 BDNF allele, which is associated with reduced BDNF function, show greater anxiety-like behaviour and impaired hippocampus-dependent learning, but are more resilient to chronic stress41,56. These data underscore the complex effects of BDNF on the brain, which are highly region specific.
