As in PD patients (Ho et al., 1998; Miller et al., 2006a,b), Pink1–/– rats have been shown to have difficulty in sustained chewing and swallowing and show diminished vocalizing and vocalization volumes (Grant et al., 2015; Cullen et al., 2018; Kelm-Nelson et al., 2018a; Johnson et al., 2020). The gene discussed is PINK1; the disease is Parkinson disease.