Highly expressed in the basal ganglia, A2ARs specially reside on GABAergic neurons of the striatum.58 These receptors are also expressed at low level in hippocampus, cortex, and other brain regions, and the extrastriatal increase in A2ARs has been detected in pathological challenge models and animal models of neuroinflammation.97 Several studies have revealed an increased level of A2AR expression in hippocampal neurons of patients with AD and in animal models of cognition.98,99 The same studies reported that inhibition or genetic deletion of A2A receptors enhanced memory function in the brain.100 A2A receptors are also expressed in areas of the brain that is rich in DA,101 providing a possibility of being considered as a target for developing drugs that prevent addiction.102
