Your brain is a constant gardener. Like the master learner it is, it picks which neural pathways to let blossom, and which to prune back, allowing more pertinent information to remain in the fore. It is just as fascinating to learn how the brain makes space for new information as it is to watch a tiny seed sprout, and grow into a massive oak, or a show-stopping orchid – and it turns out the method by which the brain achieves new learning isn’t just by strengthening existing neural pathways, but by doing something most master gardeners are extremely familiar with.
We’ve all heard the axiom, “neurons that fire together wire together,” meaning that the more often a neural synapse fires, the stronger the path is created in the brain until something that was once foreign and awkward, like speaking a new language, or learning to play the piano, becomes rote. It turns out that the brain does much more to allow us to learn amazing new skills, and it does most of it while we are sleeping.
While we rest, neurotransmitters like dopamine, seratonin, and other chemical messengers travel across synaptic connections to create new growth. ‘Glial cells’ are the constant gardeners – speeding up signals between certain neurons. Others, called ‘microglial cells’ make sure to kill the weeds, remove pests, and rake up the dried leaves – in other words, they ‘prune’ neural pathways, and synaptic connections so that our gardens don’t become overgrown.
Researchers have just discovered that synaptic connections that get used less frequently are marked by a protein, C1q (as well as others). When the microglial cells detect one of those proteins, they bond to the protein and destroy—or prune—the synapse. This is vitally important for our brains to function at their best, and also why sleep is absolutely imperative.
Our brain cells shrink by up to 60% while we sleep to create space for these glial gardeners to come in, take away the waste and prune the synapses. If you’ve ever felt like your brain was exploding with too much information after an intense day at work, school, or attempting to learn a new task – you aren’t imagining things. The brain actually does become over-wrought with excess growth, that needs to be trimmed away so that cohesive, coherent thought can take place
Even a good, long nap can help your brain function better. That’s because thinking with a sleep-deprived brain is like hacking your way through a dense jungle with a machete. You are bound to wear yourself out trying to cut through the overgrowth. Conversely, a well-pruned brain which happens while we sleep allows the same thought to happen like a walk in the park on a clear, sunny day – it’s simply easy, breezy.
Want to help those microglial cells clean house while you are still awake? Simply think about the things that are important to you. You’ll strengthen the neural synapsis associated to those goals, and the glial cells will know where just which vines in the neural jungle to hatchet through.