Amphetamine sensitization elevates CaMKIIß mRNA

Recent studies have shown that the elevation in calcium/calmodulin- dependent protein kinase II (CaMKII) may play an important role in amphetamine- induced dopamine release, as well as in the increase of dopamine D2 receptor high- affinity states in psychosis. Because amphetamine sensitization is a widely used animal model of psychosis or schizophrenia, we investigated whether amphetamine sensitiza- tion results in an overall increase in the a and b subunits of CaMKII. To answer this question, we measured CaMKII a and b subunit mRNA expression using Real-Time Quantitative PCR in amphetamine-sensitized rat striata, compared to saline-treated controls. The results were then standardized to b-glucuronidase, a housekeeping gene. Our results showed a statistically significant increase in the CaMKII b subunit, and an increase in the a subunit which did not reach statistical significance. Because the levels of both CaMKIIb and CaMKIIa play a role in neuronal function and synapse formation, the present finding of an elevated level of CaMKII b and a subunit mRNA in the amphetamine-sensitized model of psychosis points to the possibility of dysre- gulated levels of CaMKII subunits in human psychosis. Synapse 61:827-834, 2007. V C 2007 Wiley-Liss, Inc.