“…Consistent with the effect of the Val66Met SNP on neuronal development and regulated release of BDNF (Chen et al, 2006;Egan et al, 2003), a knock-in mice carrying the BDNF Val66Met SNP (BDNF Met/Met ) showed an impairment of synaptic plasticity in the mPFC and hippocampus, which might interfere with the top-down control of the amygdala, a mechanism necessary for fear regulation (Bath et al, 2012;Ninan, 2014;Ninan et al, 2010;Pattwell et al, 2012a). However, given the role of BDNF in amygdala plasticity (Rattiner et al, 2005;Rosas-Vidal et al, 2014;Roth et al, 2014), it is also plausible that the BDNF Val66Met SNP exerts a direct effect on amygdala synapses. Human BDNF Val66Met carriers continued to recruit the amygdala despite fear extinction training, suggesting an altered amygdala plasticity (Soliman et al, 2010).…”