Distribution of adenosine A2 receptor mRNA in the human brain.

The distribution of the messenger RNA coding for the recently cloned adenosine A2 receptor was studied in the human brain using in situ hybridization histochemistry. A2 receptor mRNA is exclusively detected in the medium-sized neurons of the caudate, putamen and accumbens nuclei but not elsewhere in the brain. This highly selective distribution of adenosine A2 receptor mRNA in human dorsal and ventral striatum, similar to that of adenosine A2 binding sites reported in rodents, suggests a major role in the basal ganglia physiology.