Sigma(2)-receptor regulation of dopamine transporter via activation of protein kinase C.

The elucidation of the mechanisms underlying sigma(2)-receptor activation and signal transduction is crucial to the understanding of sigma(2)-receptor function. Previous studies in our laboratory have demonstrated sigma(2)-receptor-mediated regulation of the dopamine transporter (DAT) as measured by amphetamine-stimulated release of [(3)H]dopamine (DA) from both rat striatal slices and PC12 cells. The regulation of the DAT in the PC12 cell model was dependent upon activation of Ca(2+)/calmodulin-dependent kinase II.

Nicotinic receptor-mediated regulation of dopamine transporter activity in rat prefrontal cortex.

The objective of this study was to determine whether nicotine could selectively influence dopamine levels in the prefrontal cortex as compared with other dopaminergic areas of brain. Using a superfusion system, we found that nicotine and other agonists at nicotinic acetylcholine receptors enhanced the release of radiolabeled dopamine that was stimulated by 10 microM amphetamine from slices prepared from rat prefrontal cortex. In contrast, nicotine had no effect on amphetamine-stimulated [(3)H]dopamine release from slices of nucleus accumbens nor striatum.