Abstract

What We Know & What We Don't Know

Discussion
Board

This presentation reviews what is currently known, and also what remains unknown, about the presence and normal role of catecholamine o-quinones in the brain in health and disease. They are certainly present in normal brain as they are necessary precursors of the neuromelanin in dopaminergic and noradrenergic neurons.Furthermore another metabolite of dopamine considerable evidence that dopamine neurotoxicity is mediated by DAQs acting, not on DA receptors, but on NMDA glutamate receptors. The normal role of CAQs in brain may be related to the processes involved in synaptic plasticity and dendritic spine pruning. Redox cycling between dopamine and dopamine quinone in an antioxidant rich environment may play a key role in neuroplasticty in the normal brain. Very little is known about the basic pharmacology of CAQs derived from dopamine and noradrenaline. More is known about adrenochrome which inhibits a number of enzymes (COMT, hexokinase, succinic dehydrogenase) and stimulates prostaglandin synthesis and guanylcyclase activity. Adrenochrome has also been shown to be a psychotomimetic agent and to produce EEG abnormalities. There is evidence that CAQs are involved in the pathogenesis of Parkinson's disease and schizophrenia.

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Presentation Number SAsmythies0199
Keywords: aminochromes, NAMD receptor, neuromelanin, synapse, plasticity