BDNF and Huntington disease: Conflicting studies report that cortical BDNF expression is normal in symptomatic BACHD mice (Plotkin et al., 2014) and human HD tissue samples (Ferrer et al., 2000; Gauthier et al., 2004), arguing that other downstream defects contribute to reduced BDNF neurotrophic support, such as impaired axonal transport machinery (Gauthier et al., 2004) or altered TrkB receptor signal transduction (Plotkin et al., 2014).