The Dopamine D3 Receptor Ser9Gly Polymorphism Modulates Prepulse Inhibition of the Acoustic Startle Reflex
Received 15 October 2007; received in revised form 2 January 2008; accepted 27 January 2008. published online 06 March 2008.
Background
The dopamine D3 receptor (DRD3) is suspected to modulate prepulse inhibition (PPI) in animals and humans, but definite conclusions cannot be drawn due to lack of selective DRD3 ligands. The Ser9Gly polymorphism is a common variant of the DRD3 gene and determines the gain of function of the D3 receptor. This is the first study to examine the influence of the DRD3 Ser9Gly polymorphism on human PPI.
Methods
Prepulse inhibition was measured in 101 healthy male subjects presented with 75-dB and 85-dB prepulses at 30-, 60-, and 120-msec prepulse-pulse intervals. Subjects were grouped according to their DRD3 status into a Gly/Gly, a Ser/Gly, and a Ser/Ser group.
Results
Analyses of variance showed that at all prepulse and interval conditions, Gly/Gly individuals had the lowest PPI and the greatest onset latency facilitation and Ser/Ser individuals had the highest PPI and the lowest onset latency facilitation, while Ser/Gly individuals were intermediate.
Conclusions
These results suggest that PPI is modulated by the D3 receptor and its levels depend on the Ser9Gly polymorphism.
Department of Psychiatry and Behavioral Sciences, Faculty of Medicine, University of Crete, Heraklion, Greece.
Address reprint requests to Panos Bitsios, M.D., Ph.D., Department of Psychiatry and Behavioral Sciences, Faculty of Medicine, PO Box 2208, University of Crete, Heraklion 71003, Crete, Greece
ABSTRACT