Scientists at the University of North Carolina at Chapel Hill (UNC) have reported - for the first time - a burst in new brain cell development during abstinence from chronic alcohol consumption. The UNC findings appear in the Journal of Neuroscience.
"When used in excess, alcohol damages brain structure and function. Alcoholics have impairments in the ability to reason, plan or remember," said UNC researcher Fulton T. Crews. "A variety of psychological tests show alcoholics have a difficulty in ability to understand negative consequences."
While the researchers found inhibition of brain cell development during alcohol dependency, it was followed by a pronounced increase in new neuron formation in the hippocampus within four-to-five weeks of abstinence. This included a twofold burst in brain cell proliferation at day seven of abstinence. "We looked at dividing cells after our four-day binge model of alcohol dependency and confirmed what we previously observed: When the animals were intoxicated, the measure of dividing cells decreases," said co-researcher Kim Nixon.
"And after abstinence for one week, we saw a huge burst in the number of new cells being born."
"This is really the first biological measure of a major change in neuronal structure consistent with changes that are known to occur when individuals are able to stop drinking," said Crews.
For decades, neuroscientists believed the number of new cells, or neurons, in the adult brain was fixed early in life. Adaptive processes such as learning, memory and mood were thought tied to changes in synapses, connections between neurons. More recently, studies have shown that the adult human brain is capable of producing new brain cells throughout life, a neurogenesis resulting in formation of hundreds of thousands of new neurons each month. "Prior to our work, everyone merely assumed that glia, the supporting cells of the brain, regenerated or that existing brain cells altered their connections," said Nixon. "We have shown a burst in new cell birth that may be part of the brain's recovery after the cessation of alcohol."