Do you remember taking all of those all-nighters in college and cramming for tests?  Living off of No-doz and staying up all night, we thought we were helping our memories.  Maybe, for the short-term tests the next day, it helped us some of the time.  But the truth is that sleep is really KEY for helping us to retain memory.  It is crucial for learning and forming long-term memories.

That is because sleep enhances the 'consolidation of memories.'  First, it shuts off the interference of everyday sensory stimuli so that the brain can concentrate on the memories.  Not only that, according to a new study by the Scripps Research Institute, sleeping  keeps the memory consolidation process steady by blocking some of the neurotransmitter dopamine, thereby reducing the forgetting signals in the brain.  

In sleep, our brains fast-forward the memories of the day in the hippocampus, which is the brain's central memory-filing system.  This strengthens the nerve cell connections and in sleep, specific  activities are replayed, sorted and selectively retained.  During sleep, this memory information is transferred from the hippocampus to the cerebral cortex for long-term memory.

Understanding the brain and its memory formation process is such an interesting subject: one that is becoming even more important to understand as the population ages and deals with many brain issues, such as the Alzheimer's Disease.  For more information, here are a few links for you to research:

Neuroscience and psychology paint more complete picture of sleep and memory

Best to sleep on it: Brain activity patterns during sleep consolidate memory

Best to sleep on it: brain activity patterns during sleep consolidate memory

Memory Consolidation

Key players responsible for learning and memory formation uncovered

Scientists identify new switch to boost memory

Remember, sleep, whether it is a full night of sleep or an afternoon nap, is the best medicine for maintaining memory.  Sleep is the 'memory tonic' for the body.