How better sleep = better brains
New insight: how sleep improves brain function
We’ve known for a long time that getting a good night’s sleep is essential for maintaining both short and long-term cognitive health.
This is partly because your neurons - the cells that largely make up your brain - are remodelled while you sleep in order to solidify your memories and get rid of anything that is ‘junk.’
This remodelling happens at the synapses*, which are the physical connections - like special ports - between neurons that allow them to communicate with each other so you can think, remember things and execute bodily functions.
(*ASIDE: All neurons - AKA cells of the nervous system - have synapses. They have crucial functions in learning and memory, and their “strengths” and sizes change within minutes or hours of when you learn something. That happens all day long, which makes for a lot of new connections each da that you actually don’t necessarily need. So, your brain “prunes” and remodels them while you sleep at night to ‘trim the fat’ and make sure that 1. your brain is not overloaded with connections, and 2. the important connections are strengthened and reinforced to can remember things in the morning. These sleep-induced processes are essential for cognitive health and to prevent neurodegeneration.)
NEW INSIGHTS
While we know that synapses get remodelled during sleep, we haven’t understood how that process works or how it is triggered.
Two recent studies (linked here and here) in one of the world’s most prestigious scientific journals, Science, now reveal important parts of the mechanisms that drive this remodelling.
A couple of key findings:
Our built-in sleep/wake cycles (circadian rhythms) drive the production of synaptic proteins required for remodelling and healthy synapse function, and that sleep deprivation interferes with this process. (In this study, they saw that the brains of the sleep-deprived mice still created the instructions for the proteins but not the proteins themselves.) Effectively, this may mean that instructions for these processes are produced by our bodies according to the time of day, but it’s the act of actually sleeping that cues the execution of those instructions. This is kind of like a printer trying to print with no paper.
2. Our bodies have two peak times for synaptic (brain-remodelling) protein production: the first is late in the evening when you start to feel drowsy, and the second is right before you wake up in the morning. The first wave consists of proteins that promote production of the essential building blocks, while the second wave are proteins that govern healthy synapse functioning.
While this new information doesn’t have any immediate therapeutic applications, it helps help us understand how to sleep deprivation affects the brain and offers insights around the mechanisms of memory formation.
Perhaps in the future, we will see interventions that boost memory and cognition that target these synaptic processes directly.
Practical take-away: By maintaining a healthy, steady circadian rhythm - AKA going to bed on time and sleeping enough - and making sure you get quality sleep throughout the night (not just a certain number of hours of sleep!), you can help ensure peak production of these brain-boosting proteins, which will serve both your memory and long-term brain health. See below for tips.
Sleep tips:
One the the most frequent questions I get is “how do I improve my sleep?” My top 2 rules for getting better sleep are 1. don’t eat or drink alcohol within 3 hours of bedtime, and 2. figure out your optimal sleep schedule and stick to it. That means going to bed and waking up at the same time every single day, hopefully based on your chronotype (if you don't know yours go to www.chronoquiz.com.) This kind of steady bed time/wake time rhythm helps keep your body’s biological clocks in sync, which not only improves the quality of your sleep but also helps you function better on many levels throughout your waking life as well.
If you’re concerned that you don’t get quality sleep or your circadian rhythm is dysregulated (or you’re unsure), connect with me.
References:
Noya SB, Colameo D, Brüning F, et al. The forebrain synaptic transcriptome is organized by clocks but its proteome is driven by sleep. Science. 2019;366(6462)
Brüning F, Noya SB, Bange T, et al. Sleep-wake cycles drive daily dynamics of synaptic phosphorylation. Science. 2019;366(6462)
