Effects of GRIK3 receptor knock-out on the development and expression of cocaine locomotor sensitization in rats: sex differences

Abstract

The GRIK3 gene encodes gluek3, which is a kainite-type glutamate receptor that can function as a ligand-activated ion channel in mammals and is speculated to be linked to many psychiatric illnesses such as alcohol dependence, schizophrenia, bipolar disorder. It is hypothesized that GRIK3 receptors may contribute to susceptibility to cocaine addiction and may influence changes in the induction and expression of locomotor sensitization after repeated cocaine exposure in rats. Sensitization to a drug occurs when a greater response is elicited by the same drug dose, and animals show this through increased locomotor activity (DiFranzia and Wellman 2007). Although these rats are not self administering cocaine, neuroadaptions for addiction influence reward systems to be sensitized to drugs and stimuli associated with the drug (Robinson and Berridge 2001). Therefore, by placing rats in a locomotor track and recording beam breaks ever ninety degrees, we can measure response to cocaine and evaluate for sensitization.