Sleep and Productive Forgetting

We’ve blogged numerous times over the years about sleep, from sleep recommendations to tips for waking up. Meanwhile, scientists have been spending many of their waking moments trying to learn more about this important but not wholly understood phenomenon. The New York Times highlighted some recent findings.

Examination of mouse brains has revealed that their brain synapses, and accompanying amounts of surface proteins, are smaller when sleeping than when awake. Researchers were able to use a chemical to block this synaptic pruning in some mice but not others. All of the mice, before any were exposed to the chemical, were given a mild shock when they walked over a particular section of the floor. The mice that were then exposed to the chemical overnight, so were prevented from pruning their brain synapses, exhibited trepidation regardless of what environment they were placed in the next day. The mice that had been able to do their regular synaptic pruning only froze up in the particular area where they had received the shock.

The results suggested to one of the researchers that “You can forget in a smart way.” In this experiment, synaptic pruning seemed to narrow down or restrict the shock memory to the particular environment in which it occurred. At least one function of sleep may be for the brain to do some strategic self-editing to keep memories from becoming fuzzy.

photo credit: Rachel Fury via FlickrCC