For decades, scientists have puzzled over whether the brain can change during the course of a lifetime. Today, we know it can.
Neuroscientists call this “brain plasticity.” Also known as neural plasticity or neuroplasticity, it sometimes involves a process called neurogenesis, which is defined as the creation of new neurons.
While there’s still a lot we don’t know about the brain, experts agree its structure and function are far from static. This article describes current research into neural plasticity and neurogenesis, how they affect aging, and what you can do to boost your brain health.
“Brain plasticity” refers to the nervous system’s ability to transform and reorganize itself throughout your life span, usually in response to experiences or stimuli.
This process isn’t unique to humans, or even mammals or vertebrates. In fact, even insects exhibit neural plasticity.
In human fetuses, the brain starts to develop a few weeks after conception. While genes provide the blueprint for brain development, environmental factors — such as stress, hormones, diet, drugs, and relationships — can greatly influence the outcome. This is known as developmental brain plasticity, and it continues throughout childhood.
Brain development was once thought to stop completely a few years after puberty, but we now know the brain continues to adapt and change well into adulthood.
While the changes are definitely less dramatic than those of the developing brain, they are crucial to our ability to learn, form memories, and recover from illnesses and injuries.
Neurons form the basis of the nervous system. These cells are responsible for receiving and processing information from the outside world, as well as relaying messages throughout the body.
Neurons communicate via electrical and chemical signals that travel across a gap called a synapse. These connections form intricate neural networks that help us learn.
One way of thinking about how brain plasticity works is a catchphrase coined by the neuroscientist Donald Hebb: “Neurons that fire together, wire together.” It means that when neurons are active, connections are reinforced.
With that said, brain plasticity is a complex process that involves molecular, cellular, and structural mechanisms that can change throughout your life.
Plasticity tends to be greatest in utero and during the first years of life, when the brain is developing rapidly. While the adult brain is also capable of change, the possibilities are more limited.
There are many documented instances of brain plasticity throughout the human life span, some of which are described below.
Mental health during pregnancy
According to a 2020 research review, strong mental health during pregnancy is associated with increased intelligence in 2-year-old infants. This suggests a mother’s mental well-being during pregnancy has an influence on the baby’s brain development.
Furthermore, researchers in a 2022 study involving 97 mother-infant pairs reported that the volume of the left part of the hippocampus in a developing fetus was directly linked to maternal stress during pregnancy and the child’s thinking abilities at 18 months.
Creative music therapy in preterm infants
Researchers reported increased neural activity and connectivity in areas of the brain responsible for thinking, social, emotional, and motor functions. In other words, music therapy could enhance brain development in babies who are born preterm.
Autism spectrum disorder (ASD)
According to a 2016 meta-analysis, children with ASD tend to have atypical neural activity and connectivity. This can lead to challenges with social interactions, recognition of emotions, and language skills, among other areas.
Researchers evaluated six studies that assessed brain activity following behavioral interventions designed to help people with ASD develop specific skills.
They reported that targeted training can significantly change neural activity and connections, leading to significant improvements in autism symptoms. The effects were particularly noticeable in younger children.
In other words, behavioral interventions that use the principle of brain plasticity to bolster neural networks may be helpful in mitigating symptoms of ASD.
During pregnancy and the postpartum period, new mothers undergo an array of functional and structural brain adaptations, according to a 2017 research review article.
One example of functional plasticity comes from functional MRI (fMRI) studies. They reveal that new mothers experience increased activity in neural circuits responsible for rewards, motivation, and emotional regulation.
Studies have also shown that activation in these areas is a predictor of sensitive parenting actions and strong emotional bonding with a child.
Moreover, mothers’ brains actually increase in size in the postpartum period. This is an example of structural plasticity. Researchers believe this growth occurs in brain regions associated with parenting.
Substance use disorder may cause lasting changes in areas of the brain associated with rewards and motivation, the formation of habits, and decision making processes.
The process may be similar to what happens when we learn something new through practice and reinforcement, according to a 2018 review. In the case of substance use, though, the learning isn’t advantageous.
“Neurogenesis” refers to the formation of new neurons. It’s an important part of brain plasticity, but it’s not the only example.
New neurons mostly form before birth and in the early years of life, when the brain is still developing. They then migrate and differentiate to carry out a wide range of functions within the nervous system. There are thousands of different types of neurons in the human brain.
It’s only recently that neuroscientists have discovered evidence of adult neurogenesis, but it’s still a subject of intense debate.
According to a 2019 review, neurogenesis likely occurs in two brain areas:
- In the hippocampus, the formation of new neurons in this area of the brain may play a role in long-term memory and learning.
- In the subventricular zone, the creation of new neurons in this area has been linked to our sense of smell.
Brain plasticity is critical to human development from the moment the nervous system starts to form in an embryo. In fact, it’s hard to imagine what human life would look like if the brain didn’t change and evolve.
Without the ability to learn based on new stimuli, would we still be unique individuals? Would we be able to hone skills, learn facts, or create memories? Would people who experience a stroke or traumatic brain injury be able to recover?
Brain plasticity plays a critical role in all these adaptive abilities.
A number of current studies also focus on the importance of neuroplasticity and neurogenesis in aging. In particular, evidence from animal studies suggests that hippocampal neurogenesis may protect against cognitive decline, along with age-related illnesses, such as Alzheimer’s disease and stroke.
Brain plasticity varies a lot from one person to the next. While age is a crucial factor, researchers believe your personality and lifestyle also influence it.
If that’s the case, it may be possible to boost neuroplasticity and neurogenesis with certain behaviors. This includes the following proven actions:
- Regular exercise. Getting regular exercise promotes neuroplasticity. To incorporate exercise into your life and continue doing it regularly, find an activity you enjoy that gets you moving.
- Stress management. Stress can reduce neural plasticity and neurogenesis, according to a 2022 review. Although it’s not possible to avoid stress altogether, you can take steps to minimize and manage its effects.
- A nutritious diet. Research suggests that diets high in fat and sugar can harm adult neurogenesis. On the other hand, consuming polyphenols, such as turmeric, can promote neuroplasticity.
- Lifelong learning. Learning is a proven way to boost brain function. Try taking a class, learning a new language, playing an instrument, reading books, playing games, or doing puzzles.
- Good quality sleep. Sleep plays a role in synaptic plasticity, according to a 2017 study. Try to prioritize your sleep and aim for 7 to 8 hours of sleep each night.
- Mental health care. Studies show that depression can prevent neural plasticity. In contrast, antidepressant treatments may increase adult neural plasticity.
- Substance use disorder treatment. Alcohol and substance use disorders can decrease neuroplasticity, according to a 2020 review. If managing or stopping alcohol or drug use is difficult, help is available right now.
Plasticity allows your brain to adapt to new situations, experiences, and environments over the course of your life span. It’s most prominent in embryos and babies, whose brains are still developing, and slows down with increasing age.
Still, there are many examples of neuroplasticity in adulthood. In fact, research suggests areas of the brain involved with learning and memory can even grow new neurons. This process is called neurogenesis.
Increased brain plasticity has also been linked to a lower risk of cognitive decline associated with aging. A number of simple steps can help boost brain plasticity, including exercising regularly, eating a balanced diet, managing stress, and continued learning.