GFAP and Parkinson disease: Because neuroinflammation often occurs in response to damage and is a key component of AD and PD pathology (Tansey et al., 2022; Thakur et al., 2022), and glial activation can be impeded by NE signaling (Liu et al., 2019), we assessed immunoreactivity of the astrocyte marker GFAP and the microglial marker Iba-1 in the LC and target regions.