ADORA2A and Alzheimer disease: We took advantage of a model of early AD based on the intracerebroventricular (icv) administration of a suspension of soluble β-amyloid peptides monomers and oligomers (Aβ1–42) to test if hippocampal A2AR upregulation was a precocious event, i.e., pre-dating hippocampal-dependent memory deficits.