Autoradiographic evidence of [3H]SCH 23390 binding sites in human prefrontal cortex (Brodmann's area 9)

The distribution of dopamine D-1 receptors has been determined in human prefrontal cortex (Brodmann's area 9) by an in vitro light microscopic autoradiographic method. Dopamine D-1 receptors were localized by using [3H]SCH 23390 as a ligand. Our results indicated that [3H]SCH 23390 binding to slide-mounted tissue sections of human brain is specific, saturable, and of high affinity. Lamina Va contained the highest density of D-1 receptors, with a Bmax value of 11.2 +/- 1.3 fmol/mg tissue. The KD values for [3H]SCH 23390 in all laminae ranged from 2.6 to 3.2 nM. Competition studies performed with [3H]SCH 23390 indicated a pharmacologic profile consistent with labeling of the D-1 receptor.