Dopamine release from rat pheochromocytoma (PC12) cells and rat brain striata induced by a series of straight carbon chain aldehydes with variations in carbon chain length and functional groups

Abstract

Green odor compounds, a group of 6-carbon (C6) aldehydes and alcohols, are able to enhance dopamine release from pheochromocytoma (PC12) cells, rat brain striatal slices, and brain striata in living rats. In this study, we examined the effects of aldehydes and alcohols with varying carbon chain lengths (2–9 carbons) and functional groups on dopamine release in PC12 cells, brain slices, and living rat brain. In PC12 cells, n-aldehydes and n-alcohols promoted dopamine release, and this effect was stronger as the carbon chain length increased. In rat brain slices, however, the maximum dopamine release was detected when stimulated by n-hexanal, while n-nonanal promoted the lowest level of release. In addition, C6 compounds with a hydroxyl, aldehyde, or carboxyl group enhanced the dopamine release from PC12 cells and striatal slices. In the microdialysis study, n-hexanal and n-hexanol enhanced dopamine release, while n-nonanal promoted lower activity than n-hexanol. The relationship of the concentration of the odor-related compounds and the amount of dopamine released differed between PC12 cells and brain slices. Dopamine release in the living rat brains was similar to that in brain slices. These data suggested that the length of the carbon chain correlated with the strength of dopamine release, and the functional groups further modified it. The distinction between PC12 cells and rat striata might be due to the differences in the cell structure or the target molecules within the cells.