Synaptic Pruning in Adolescence: Why Your Brain Chooses What to Keep
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Have you ever thought about why you forget some things but seem to remember others? For example, you might forget the name of the person you met last week but still remember the joke your friend told you years ago. If this is you, then you are not alone. This act is defined as synaptic pruning, a natural process in the brain where unnecessary or weak connections between neurons are eliminated. Synaptic pruning in adolescence is a natural process where the brain strengthens useful neural pathways and cuts away weaker ones. This process shapes cognition, memory, and behavior as you grow into adulthood.
What Are Neurons and Synapses?
Your brain is arguably one of the most important organs in your body. It signals all actions and regulates vital functions. But in order to do this, neurons play a major role. Neurons help in communicating with cells, receiving information, processing it, and transmitting it to other neurons or to muscles and glands. Neurons are able to perform these actions through the synapse, a small junction between neurons that enables communication and information transfer. These connections are things you are born with. A child can have over 1,000 trillion synapses by the time they are two or three years old. This overproduction of synapses starts to slow down as the child gets older. This is the process called pruning. You can think of pruning like cleaning out your closet. You get rid of the old clothes that you don’t want and keep the things that you still use.
Why So Many Synapses in Childhood?
You may wonder, why do children have trillions of synapses at such a young age? In a child’s brain, new connections form every second. These build the fundamental circuits for learning and developing. But pruning also starts at this young age, especially in the prefrontal cortex, a part of the brain responsible for decision-making, working memory, impulse control, social behavior, and emotional regulation. As a child grows, pruning specific memories begins to shape their identity and allows for the growth of gray matter. Giedd et al. (1999, Nature Neuroscience) showed that gray matter increases in childhood, then declines in adolescence due to pruning. This is why teenagers start to show an increase in emotion and impulsivity at this age.
Why the Brain Lets Go of Information
Now you may start to wonder, why would our brain willingly let go of information that could potentially make us smarter? The occurrence of pruning is significant because it allows for faster and more efficient use of your brain. Pruning allows you to learn more because useful pathways are being reinforced and strengthened as you experience things. For example, as you play the piano, you form many synapses. The more you practice, the more these synapses get reinforced. This allows you to remember what you learn and apply it later. Pruning is also linked to critical thinking. When your brain knows how to eliminate unnecessary information and clutter, it allows you to comprehend, make connections, and apply knowledge more effectively.
The Benefits of Pruning
Pruning isn’t just about forgetting. It’s about refining. Think of it like sculpting you chip away at the extra material so the actual figure can emerge.
It makes the brain’s work more energy-efficient.
It helps form stronger long-term memories.
It encourages the brain to focus on what’s relevant and important.
It supports skills like language, problem-solving, and creativity.
Adolescents, though sometimes frustrated by forgetfulness, are actually undergoing a crucial stage of brain development that sets them up for adult cognition.
The Risks of Too Much or Too Little Pruning
Although pruning is linked to many benefits in a growing brain, there are risks when the balance is off. Too much pruning or too little pruning can lead to disorders.
Too much pruning: An individual may be prone to schizophrenia. When the brain eliminates too much information, it begins to impact a person’s ability to think, feel, and behave clearly. Sekar et al. (2016, Nature) found a genetic link between schizophrenia risk and overactive pruning in adolescence.
Too little pruning: This can be linked to autism. When there are too many connections, the brain can become overloaded with information. This connectedness may interfere with normal social and cognitive processing.
So while pruning helps the brain run efficiently, imbalance in this process shows how delicate and important it really is.
Why Synaptic Pruning Matters to You
It might sound like pruning is just some technical brain process, but it actually impacts your everyday life. The way you study, what you remember, and how you make decisions are all shaped by which synapses your brain decides to keep. When you practice something repeatedly, like solving math problems or learning a new sport, your brain keeps those useful connections. But the things you never use, like the random person’s name you never said again, get pruned. This is why your brain feels both powerful and selective.
Final Thoughts
Synaptic pruning is one of the most fascinating processes in brain development. It helps you move from the openness of childhood to the efficiency of adulthood. It’s the reason you forget certain things and remember others. It shapes your skills, your personality, and even your risks for certain disorders. While pruning can sometimes lead to challenges when it’s unbalanced, most of the time it’s a process that makes you smarter, faster, and more capable. So the next time you forget something small, remember this: your brain isn’t failing you. It’s pruning. It’s making room for the things that will matter most in the long run.
Reference
SECTIONS: https://www.psychiatryadvisor.com/news/research-uncovers-genetic-variant-underlying-schizophrenia/