A person who drinks too much alcohol may be able to perform complicated tasks, such as dancing, carrying on a conversation or even driving a car, but later have no memory of those escapades. These periods of amnesia, commonly known as “blackouts,” can last from a few minutes to several hours.
Now, at Washington University School of Medicine in St. Louis, neuroscientists have identified the brain cells involved in blackouts and the molecular mechanism that appears to underlie them. They report July 6, 2011, in The Journal of Neuroscience, that exposure to large amounts of alcohol does not necessarily kill brain cells as once was thought. Rather, alcohol interferes with key receptors in the brain, which in turn manufacture steroids that inhibit long-term potentiation (LTP), a process that strengthens the connections between neurons and is crucial to learning and memory.
Better understanding of what occurs when memory formation is inhibited by alcohol exposure could lead to strategies to improve memory.
More here The biology behind alcohol-induced blackouts.