Sleep after learning encourages brain cells to make connections with other brain cells, research shows for the first time.
The connections, called dendritic spines, enable the flow of information across the synapses.
The findings, published in the prestigious journal Science, are the first to show physical changes in the motor cortex resulting from learning and sleep (Yang et al., 2014).
One of the study’s authors, Wen-Biao Gan, PhD, said:
“We’ve known for a long time that sleep plays an important role in learning and memory. If you don’t sleep well you won’t learn well.
But what’s the underlying physical mechanism responsible for this phenomenon?
Here we’ve shown how sleep helps neurons form very specific connections on dendritic branches that may facilitate long-term memory.
We also show how different types of learning form synapses on different branches of the same neurons, suggesting that learning causes very specific structural changes in the brain.”
The results come from studies in mice, which were genetically engineered with a fluorescent protein in their neurons.
With the use of a laser-scanning microscope, the fluorescent protein allowed the scientists to track and image the dendritic spines before and after they learnt a new skill; in this case balancing on a spinning rod.
Some of the mice were allowed to sleep after they had learned to balance on the rod, others were not.
In the brains of those that had slept, there was more growth of dendritic spines.
In addition, the type of task the mice learnt –whether they ran forward or backward across the rod — affected where the dendritic spines grew.
“Now we know that when we learn something new, a neuron will grow new connections on a specific branch.
Imagine a tree that grows leaves (spines) on one branch but not another branch. When we learn something new, it’s like we’re sprouting leaves on a specific branch.”
More on the science of sleep: Unwind: The Science of Rest, Relaxation and Sleep
About the author
Psychologist, Jeremy Dean, PhD is the founder and author of PsyBlog. He holds a doctorate in psychology from University College London and two other advanced degrees in psychology.
He has been writing about scientific research on PsyBlog since 2004. He is also the author of the book “Making Habits, Breaking Habits” (Da Capo, 2013) and several ebooks:
- Accept Yourself: How to feel a profound sense of warmth and self-compassion
- The Anxiety Plan: 42 Strategies For Worry, Phobias, OCD and Panic
- Spark: 17 Steps That Will Boost Your Motivation For Anything
- Activate: How To Find Joy Again By Changing What You Do
Image credit: Ryan Ritchie
→ This post is part of a series on the science of rest, relaxation and sleep:
- The Peaceful Mind: 5 Step Guide to Feeling Relaxed Fast
- 6 Easy Steps to Falling Asleep Fast
- Rethinking The Stress Mindset: Can You Find The Upside of Pressure?
- Can Everyday Hassles Make You Depressed?
- Perform Better Under Stress Using Self-Affirmation
- Venting Emotions After Trauma Predicts Worse Outcomes
- 8 Ironic Effects of Thought Suppression
- How To Get Rid of Negative Thoughts
- 5 Relaxation Techniques for Anxiety
- Bad Night’s Sleep? Blame the Full Moon
- Later School Start Times Improve Sleep and Daytime Functioning in Adolescents
- How Sleep After Learning Enhances Memory