A comparison of the patterns of striatal Fos-like immunoreactivity induced by various dopamine agonists in rats

In contrast to the highly patchy patterns of Fos-like immunoreactivity seen in the rostral striatum after administration of a number of dopamine agonists, the monoamine uptake blocker cocaine has been reported to produce a relatively homogeneous pattern of gene expression. In the current study we extended these observations by using a quantitative technique to demonstrate that while amphetamine and apomorphine produce patchy striatal Fos expression, the selective dopamine uptake inhibitors amfonelic acid, nomifensine and GBR-12909 all, like cocaine, produce near random patterns of gene expression. These findings suggest that the production of relatively 'non-patchy' patterns of immediate early gene expression may be a general property of dopamine transport inhibitors unrelated to any unique pharmacological properties of cocaine.