A study by Duke University found that heavy drinking can also affect the parts of the brain that control emotional maturity.
Study lead Dr Mary-Louise Risher said: "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.
"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."
Over a 16-day period during their adolescence, male lab rats were plied with enough alcohol to approximate a binge-drinking episode on 10 separate occasions. The amount of alcohol given to the young rats was enough to cause impairment -but not enough to cause them to nod off or pass out. The hard-partying young rats were then returned to their normal living conditions for 24 to 29 days, during which they were allowed to mature normally into adulthood.
When researchers compared the cells of these rats' hippocampal area to those of rats who matured without exposure to alcohol, they saw neurons with stunted and misshapen connections to other neurons. When stimulated, those neurons over-reacted, disrupting the delicate balance between excitement and inhibition that makes the brain's cells function properly.
The researchers concluded the brains of the adult rats that had binged in adolescence looked and acted like those of immature rats. But they weren't immature in a stronger, faster, more youthful way; they were immature in a way that suggested they might never likely settle down and function in ways that allow learning to proceed and memories to be built, stored and maintained efficiently.
"It's quite possible that alcohol disrupts the maturation process, which can affect these cognitive function later on," added Risher. "Ongoing studies will explore that possibility further."