When considering that synaptic plasticity and memory functions are impaired in the brains of AD patients [82], and that GCs enhance memory consolidation in which BDNF has essential roles as a synaptic modulator [83,84], these results, including ours, suggest that an “appropriate dose” of GCs may play a beneficial role for patients with HD and AD by promoting neuronal survival and memory consolidation through the enhanced neuronal transport of BDNF. This evidence concerns the gene BDNF and Huntington disease.