The astrocytic proteins, including GLT-1 and GS, were reduced in the PD group, limiting the conversion of Glu to glutamine (Gln), whereas their expression was upregulated in the PD + Ex group, thereby increasing the Gln levels (Feng et al., 2021; Churchill et al., 2017; Sconce et al., 2015; VanLeeuwen et al., 2010). The gene discussed is GLUL; the disease is Parkinson disease.