The Effects of Sleep Deprivation on Memory

“Fatigue is the best pillow.” – Benjamin Franklin

Many people began to experiment with “pulling all nighters” when they were in high school or college in the attempt to study or “cram” for an upcoming test.  Some people seem to swear by this strategy, while others would never (pardon the pun) dream of such a thing.  For many, the consequences of staying up all night (for whatever reason) include grogginess, difficulty focusing, and a fuzzy memory the next day.

Researchers at Penn were interested in studying the effects of sleep deprivation on memory.  They discovered a specific part of the brain and a neurochemical basis responsible for sleep deprivation’s effects on memory.  The study, led by Ted Abel, professor of biology at Penn’s School of Arts and Sciences and director of the Biological Basis of Behavior Program, attempted to understand the role of the nucleoside adenosine in the hippocampus, which is the area of the brain known to be associated with memory function.

Abel explained that “researchers have known that sleep deprivation results in an increased level of adenosine in the brain … There is accumulating evidence that this adenosine is really the source of a number of the deficits and impact of sleep deprivation, including memory loss and attention deficits.  One thing that underscores that evidence is that caffeine is a drug that blocks the effects of adenosine.”

Abel and his colleagues pumped a drug into the brains of mice that would block a particular adenosine receptor in the hippocampus.  If this receptor was indeed related to memory impairment, then the sleep-deprived mice would act as if the additional adenosine in their brains was not present.

They tested to see whether or not the mice were truly sleep deprived by using an object recognition test.  On day one, the mice were put into a box with two objects that they were allowed to explore while being videotaped.  During the night, researchers woke up some of the mice during their typical 12-hour sleep schedule.

On day two, the mice were put back in the box, with one of the objects from day one being moved.  Abel explains the importance of this by saying, “Mice would normally explore that moved object more than other objects, but with sleep deprivation, they don’t.  They literally don’t know where things are around them.  Both sets of treated mice did explore the moved object as if they had had a full night’s sleep (i.e., they were unaware that they were sleep deprived).

The research finding that interrupting the pathway at either end (i.e., where the adenosine comes from and where it goes) results in mice that show no visible memory impairments is a huge step forward for understanding how to manage these same impairments in humans.

Abel concludes by explaining, “Our sleep deprivation experiments are the equivalent of losing half of a [night’s] sleep for a single night.  Most of us would think that’s pretty minor, but it shows just how critical the need for sleep is for things like cognition.”

How do you notice that your own memory and general cognitive abilities are different when you have had a poor night’s sleep?  This study is another reminder of the consequences that must be willing to face if we sacrifice our body’s need for adequate sleep.  In a previous post, I discuss specific sleep hygiene strategies to promote restful sleep.  Consider the importance of developing a healthy sleep routine to your cognitive functioning and well-being.

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University of Pennsylvania (2011, May 18). Roots of memory impairment resulting from sleep deprivation identified. ScienceDaily. Retrieved June 11, 2011, from http://www.sciencedaily.com­ /releases/2011/05/110517171118.htm

Featured image: crash & burn (explored) by Evil Erin / CC BY 2.0