TAAR1 and Parkinson disease: To further substantiate whether the levels of the TAAR1 protein along the olfactory pathway were reduced in the subacute PD mice, we employed immunohistochemical staining and western blot to assess TAAR1 protein levels within the OB (Figure 6A,B), the PC (Figure 6C,D), the hypothalamus (Figure 6E,F), and the caudate putamen (CPu) (Figure 6G,H).