Brett Smith for redOrbit.com – Your Universe Online
A team of American researchers has stumbled upon a way to prevent binge drinking in animal subjects, according to a new report in the journal Frontiers in Neuroscience.
By using light to stimulate specific neurons in the brain, the study team was able to show a cause-and-effect relationship between the discharge of dopamine in the brain and drinking behaviors of animals.
“For decades, we have observed that particular brain regions light up or become more active in an alcoholic when he or she drinks or looks at pictures of people drinking, for example, but we didn’t know if those changes in brain activity actually governed the alcoholic’s behavior,” study author Caroline E. Bass, an assistant professor of pharmacology and toxicology in the University at Buffalo’s School of Medicine and Biomedical Sciences.
For the study, the research team trained laboratory rats to model binge-drinking behavior in humans.
“By stimulating certain dopamine neurons in a precise pattern, resulting in low but prolonged levels of dopamine release, we could prevent the rats from binging. The rats just flat out stopped drinking,” Bass said.
The researchers were able to activate dopamine neurons through new type of deep-brain stimulation called optogenetics. The technique uses light instead of the electrical impulses used by traditional methods to stimulate neurons.
“Electrical stimulation doesn’t discriminate,” Bass explained. “It hits all the neurons, but the brain has many different kinds of neurons, with different neurotransmitters and different functions. Optogenetics allows you to stimulate only one type of neuron at a time.”
The pharmacology professor used a virus to place a specially-designed, light-responsive protein into the rodents’ brains. While the protein was activated, it stimulated a specific cohort of dopamine neurons in the subjects’ brains.
“I created a virus that will make this protein only in dopaminergic neurons,” said Bass, who has extensive experience working with viruses.
The UB professor said neuronal pathways explored by this research are involved in many cognitive disorders. This means that the study results have applications in treating mental illnesses and neurological diseases that are dopamine-related. Bass noted that this study’s capacity to target specific dopamine neurons could possibly lead to the use of a novel gene therapy for the brain.
“We can target dopamine neurons in a part of the brain called the nigrostriatal pathway, which is what degenerates in Parkinson’s disease,” she said. “If we could infuse a viral vector into that part of the brain, we could target potentially therapeutic genes to the dopamine neurons involved in Parkinson’s. And by infusing the virus into other areas of the brain, we could potentially deliver therapeutic genes to treat other neurological diseases and mental illnesses, including schizophrenia and depression.”
The new study, which involves mapping the neuronal circuits behind specific behaviors, is a primary focus of President Obama’s Brain Research for Advancing Innovative Neurotechnologies initiative (BRAIN). Run under the National Institutes of Health (NIH), BRAIN aims to “fill major gaps in our current knowledge and provide unprecedented opportunities for exploring exactly how the brain enables the human body to record, process, utilize, store, and retrieve vast quantities of information, all at the speed of thought,” according to a statement on the NIH website.
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