Pridopidine has also been found to increase brain-derived neurotrophic factor (BDNF) signaling, improve motor function and extend the lifespan of Huntington's disease model mice, and may exert Sigma-1R-dependent neuroprotective effects in neurons from such mice (Squitieri et al., 2015; Geva et al., 2016; Ryskamp et al., 2017). This evidence concerns the gene BDNF and Huntington disease.