LONG-TERM COCAINE ADMINISTRATION IS NOT NEUROTOXIC TO CULTURED FETAL MESENCEPHALIC DOPAMINE NEURONS

The psychostimulants cocaine and methamphetamine produce their euphori c effects through an interaction with the mesolimbic dopamine system. Methamphetamine, unlike cocaine, has been shown to be neurotoxic to bo th dopaminergic and serotonergic systems. We have previously determine d that a 6 day exposure to methamphetamine causes neuronal damage to t yrosine hydroxylase-immunopositive cells in our tissue culture model o f the mesencephalon. Over the same exposure period, cocaine neither im paired neuronal function nor altered dopamine cell survival. To test w hether a longer exposure period to cocaine would alter dopamine functi on, we added cocaine (100 muM) to the cultures once daily for either 8 or 11 days and examined changes in dopamine uptake, cell survival and morphology 24 h after the last administration. Cocaine did not produc e any signs of neurotoxicity in the mesencephalic cultures.