Parkinson's disease and drug abuse:
why study dopamine?
The Trudeau laboratory is interested in the chemical messenger of the brain called
"dopamine". But why should we be interested in messengers or "neurotransmitters" of this type? The main reason is that many diseases such as Parkinson's disease, schizophrenia and drug abuse are accompagnied by pertubations of dopamine production and release in the brain. In order to discover new strategies to treat such disorders, it is essential to know more about how the cells that produce dopamine in the brain function.
Parkinson's disease is a severe degenerative brain disease that is presently impossible to cure. The most visible symptoms of the disease are those that affect movement, including resting tremor, slowing of movement and freezing episodes. These symptoms are caused in great part by the loss of a subgroup od dopamine-producing neurons in the brain. The disease is also incapacitating because of the multiple other non-motor symptoms, including loss of the sens of smell, sleep disturbances and peripheral nervous system impairments. The exact causes of Parkinson's disease are still the subject of intense investigation. However, dysfunctions of a number of basic cellular processes including energy production by mitochondria, elimination of pathological protein aggregates and excessive production of reactive oxygen species appears to be at the heart of the disease. The medications presently available for this disorder are essentially symptomatic, but unfortunately do not slow down the gradual loss of dopamine-producing neurons with age.
Drug dependence is characterized by the compulsive seeking and consumption that often develops following repeated exposures to such molecules. The development of a dependence depends on multiple factors including the type of drug, the route of drug administration, the frequency of drug use, stress etc.. Genetic predisposing factors are also probably involved. Although different drugs (cocaine, alcohol, nicotine, heroin etc.) have different physiological and psychological effects, most of them act, one way or another, by influencing the release of dopamine in the brain. Drugs seem to leave a long-lasting “trace” in the brain, something like a form of long-term memory. Very little if any pharmacological strategies are presently available to treat the vicious cycle of compulsive drug use.
Research is our hope
The research that is presently performed in the laboratory of Dr. Trudeau aims to provide a better understanding of the fine mechanisms that control dopamine release and the origin of the vulnerability of dopamine neurons. Our research is performed using mice as a research subject, a species that has a brain structure that is surprizingly similar to that of humans. Our work involves mostly basic, fundamental research, but the hope is that such work will lead to the identification of new strategies to identify targets for thetreatment of diseases like Parkinson's disease, schizophrenia and drug abuse.