ADORA2A and brain disorder: A2AR up-regulation mostly occurs in synapses, in accordance with the involvement of synaptic alterations at the onset of most brain diseases (e.g., Rebola et al., 2005; Kaster et al., 2015; Viana da Silva et al., 2016; Canas et al., 2018), but is also observed in glia cells in the progression of chronic brain diseases (Matos et al., 2012; Orr et al., 2015; Barros-Barbosa et al., 2016; Patodia et al., 2020).