Additionally, nuclei associated with the autonomic nervous system were shown to be hyperactive in HD mice models [258] and restoring levels of brain-derived neurotrophic factor (BDNF) or signalling through ryanodine receptors in sympathetic nuclei has been shown to ameliorate changes to heart rate and/or altered electrical activity in mouse models of HD [221,278]. This evidence concerns the gene BDNF and Huntington disease.