A new study released by researchers at Duke Medicine has concluded that heavy drinking during adolescence controls learning and memory and causes changes in the brain structure. The study published in the journal Alcoholism revealed how structural brain abnormalities can influence behavior in adulthood. Teenage drinking and the response to underage drinking is a public health burden.
“In the eyes of the law, once people reach the age of 18, they are considered adult, but the brain continues to mature and refine all the way into the mid-20s,” said lead author Mary-Louise Risher, a postdoctoral researcher in the Duke Department of Psychiatry and Behavioral Sciences.
“It’s important for young people to know that when they drink heavily during this period of development, there could be changes occurring that have a lasting impact on memory and other cognitive functions,” Risher said.
The study used rat models to investigate the impact of long term alcohol consumption on learning and motor function. Rats were periodically exposed to levels of alcohol that would lead to impairment but not sedation in humans for a period of 16 days. Rats were allowed to mature into adulthood over 24-29 days, without further exposure to adulthood.
Researchers specifically examined a process called long-term potentiation (LTP) in the hippocampus. LTP is neural process by which the brain synapses strengthen as they are repeatedly used to learn new things or recollect memories.
The study revealed that alcohol impacts on LPT production and changes the way the hippocampus and other regions of the brain function and how the cells appear, including dendrites, which are involved in neuronal communication. The dendritic spines had a lanky and spindly appearance, as though they were immature.
“It’s quite possible that alcohol disrupts the maturation process, which can affect these cognitive function later on,” said Dr. Risher. “That’s something we are eager to explore in ongoing studies.”
Adolescent intermittent alcohol exposure: persistence of structural and functional hippocampal abnormalities into adulthood, Mary-Louise Risher, et al., Alcoholism: Clinical and Experimental Research, doi: 10.1111/acer.12725, published online 27 April 2015, abstract.