A study published in the November 8 issue of Neuroscience looked at the effects of drinking alcohol on the brain of rats. According to the study abstract, the rats “drinking regime resulted in an average blood alcohol concentration of approximately 0.08%,” the legal driving limit in the U.S. According to ScienceDaily:
The researchers discovered that at this level of intoxication in rats -- comparable to about 3-4 drinks for women and five drinks for men -- the number of nerve cells in the hippocampus of the brain were reduced by nearly 40 percent compared to those in the abstinent group of rodents. The hippocampus is a part of the brain where the new neurons are made and is also known to be necessary for some types of new learning.
First author M. L. Anderson commented to ScienceDaily:
Moderate drinking can become binge drinking without the person realizing it. In the short term there may not be any noticeable motor skills or overall functioning problems, but in the long term this type of behavior could have an adverse effect on learning and memory.
The study was conducted by researchers working in Behavioral and Systems Neuroscience in the Department of Psychology at Rutgers University and at the University of Jyvaskyla in Finland.