ADORA2A and schizophrenia: Reports of elevated ADORA2A expression in the hippocampus (Kurumaji and Toru, 1998) and striatum (Hwang et al., 2013) of patients with schizophrenia have been interpreted as a compensatory upregulation in response to reduced adenosine availability (Boison et al., 2012; Rial et al., 2014).