Using an emerging technique called optogenetics, which uses light to stimulate neurons, researchers at the University at Buffalo have found a way to alter alcohol drinking in rodents that mimics human binge drinking behavior.
The investigators say the findings could help scientists develop new treatments for alcoholism, other addictions and neurological and mental illnesses.
First, researchers trained rats to drink alcohol in a way that imitates human binge-drinking behavior. Then, using a type of deep brain stimulation called optogenetics, they introduced a virus in the rats' brains engineered to deliver a light-responsive protein called Channelrhodopsin-2 (ChR2) to the dopamine-controlling neurons. The viral gene-delivery strategy selectively activated ChR2 on dopamine cells in the brain's reward system, resulting in low but prolonged levels of dopamine release.
Researchers observed that this stopped the rats from drinking altogether, and even after researchers stopped the stimulation of neurons, the animals continued to avoid alcohol. The findings were published recently in Frontiers in Neuroscience.
Dopamine levels affect a number of important functions in the brain, and it's well known that the neurotransmitter plays a role in regulating mood and certain behaviors, such as binge drinking and other addictions.
Current deep brain stimulation techniques use electrical currents to stimulate brain neurons for the treatment of certain neurological conditions, such as severe tremors in Parkinson's disease patients. The promise of optogenetics, which uses light instead of electricity, is that, unlike electrical stimulation, it allows for the stimulation of one type of neuron at a time.
The researchers believe their work could also lead to the use of gene therapy in the brain to control symptoms of mental and neurological disorders.
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- see the abstract