Densities and distribution of D₁-dopamine and D₂-dopamine receptors were investigated in vitro using [³H]SCH 23390 and [³H]raclopride in receptor binding assays and autoradiography on human post mortem whole hemisphere slices to serve as anatomical correlates to PET studies using [¹¹C]SCH 23390 and [¹¹C]raclopride. In addition, the levels of dopamine and its metabolites were determined by HPLC in various brain regions. Both dopamine receptor subtypes, as well as dopamine, HVA and DOPAC, were primarily found in the basal ganglia. Very high densities of D₁-dopamine receptors were found particularly in the medial caudate nucleus, whereas D₂-dopamine receptors were evenly distributed throughout the caudate. The densities of D₁- and D₂-dopamine receptors were similar in the caudate nucleus and the putamen, whereas there were 4 to 7 times higher densities of the D₁- than of the D₂-dopamine receptors in several limbic and neocortical regions. The receptor distribution in the autoradiographic study was consistent with that demonstrated in the living human brain using [¹¹C]SCH 23390 and [¹¹C]raclopride.

Affiliations

1. From the Department of Clinical Neuroscience, Psychiatry and Psychology Section, Karolinska Hospital, Stockholm, Sweden

   • Håkan Hall
   • , Göran Sedvall
   • , Jutta Kopp
   • , Christer Halldin
   •  & Lars Farde

2. Research and Development, Astra Arcus AB, Södertälje, Sweden

   • Olle Magnusson

Corresponding author

Correspondence to Håkan Hall.

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Publication history

DOI

https://doi.org/10.1038/sj.npp.1380111