Striatal dopamine D₂ receptor quantification and superior temporal gyrus: Volume determination in 14 chronic schizophrenic subjects

Chronic schizophrenic (n = 14) and normal subjects (n = 15) were studied with magnetic resonance imaging (MRI) and positron emission tomography (PET). Two PET scans were carried out to estimate caudate dopamine D₂ receptor densities. MRI was used to measure the volume of the superior temporal gyrus. Average striatal D₂ receptor density (B(max)) was significantly higher in the schizophrenic group than in the normal group. Average left superior temporal gyral volume was significantly smaller in the schizophrenic group than in the normal group, and the same tendency was found for the right superior temporal gyrus. Thus, the main finding of this combined analysis of functional and structural neuroimaging techniques was an inverse relationship between reduced superior temporal gyral volume and elevated striatal D₂ receptor B(max) values. These preliminary findings require confirmation in larger groups of patients and control subjects.