Using a competitive reverse transcription-polymerase chain reaction (R
T-PCR) assay levels of D4 gene expression have been determined in 16 r
egions obtained from a single control brain. Relatively high levels of
expression were detected in the prefrontal and temporolimbic structur
es whilst low levels were detected in striatal regions. This pattern c
orrelates with the reported distribution of the D4 receptor. (C) 1997
Elsevier Science Ireland Ltd.