We can promote the development of new neurons well into adulthood - and here's why we should.
- Neurogenesis, the birth of neurons from stem cells, happens mostly before we are born - as we are formed in the womb, we are generating most of what we need after birth.
- After birth, neurogenesis is still possible in two parts of the brain: the olfactory bulb (which is responsible for our sense of smell) and the hippocampus (which is responsible for memory, spatial navigation, and emotional processing).
- Research from the 1960s proves creating new neurons as adults is possible, and modern-day research explains how (and why) we should promote new neuron growth.
Two parts of the brain can continue growing through neurogenesis
Neurogenesis is still possible well into adulthood in two very important parts of the human brain.
Image by EtiAmmos on Shutterstock
Although most people are aware that aging or bad habits such as heavy alcohol use can contribute to the deterioration of our brains, not many of us give thought to how we can generate new brain cells.
Neurogenesis, the birth of neurons from stem cells, happens mostly before we are born - as we are formed in the womb, we are generating most of what we need after birth.
After birth, however, neurogenesis is still possible in two parts of the brain:
- The olfactory bulb, which is a structure of the forebrain that's responsible for our sense of smell.
- The hippocampus, which is a structure of the brain located within the temporal lobe (just above your ears) - this area is important for learning, memory, regulation, of emotions and spatial navigation.
Of course, when this information first came to light back in the 1960s, the next natural question was: How do we promote neurogenesis in those areas where it's still possible?
Researchers today believe there are activities you can do (some of them may be things you already do on a daily basis) that can promote neurogenesis in your brain.
Why is it important to promote the growth of new neurons in adulthood?
We produce an estimated 700 million neurons per day in the hippocampus - this means by the time we reach the age of 50, we will have exchanged the neurons we were born within that area of the brain with new (adult-generated) neurons.
If we don't promote this exchange with the growth of new neurons, we may block certain abilities these new neurons help us with (such as keeping our memory sharp, for example).
4 ways to promote neurogenesis in your brain
Learning a new instrument helps promote neurogenesis.
Photo by DenisProduction.com on Shutterstock
Intermittent fasting
A 2015 Stanford study examined the link between intermittent fasting and neurogenesis. Calorie restriction and fasting can not only increase synaptic plasticity and promote neuron growth but it can also decrease your risk of developing neurodegenerative diseases and boost cognitive function.
Two of the most common ways you can intermittently fast are:
- 16 hours per day every day - this is a method where you are able to eat for an 8 hour period of the day and fast for 16 hours of the day. Many people begin their "fast" after dinner, pushing their morning meal far enough towards lunch that most of their "off" eating time happens while they are asleep anyways.
- 24 hours every week - this is a method where once a week you fast for an entire day. Some people prefer this method because the rest of the week can resume as normal - but for many, this is a difficult way to fast.
Traveling to new places
While traveling is something many of us enjoy — scenic routes and new fun experiences — these things also promote neurogenesis while we're on vacation. Paul Nussbaum, a clinical neuropsychologist at the University of Pittsburgh, explains that the mental benefits of traveling are very clear.
"When you expose your brain to an environment that's novel and complex or new and difficult, the brain literally reacts. Those new and challenging situations cause the brain to sprout dendrites (dangling extensions) which grow the brain's capacity."
Learning a new instrument
The mental health benefits of music have long been studied, but did you know that learning a new instrument can promote new neuron growth?
According to this 2010 study, learning to play a new musical instrument is an intense, multisensory motor experience that requires that acquisition and maintenance of skills over your entire lifetime - which of course, promotes the new formation of new neural networks.
When is the best time to begin learning a new instrument? Childhood, of course.
"Learning to play a new musical instrument in childhood can result in long-lasting changes in brain organization," according to the study mentioned above.
While learning an instrument in adulthood will also promote neurogenesis, children who began training with a musical instrument before the age of 7 have shown that they have a significantly larger corpus callosum (the area of the brain the allows communication between the two hemispheres of the brain) than many adults.
Reading novels
A study from Emory University showed there was an increase in ongoing connectivity in the brains of participants after reading the same (fiction) novel.
In this study, enhanced brain activity was observed in the region that control physical sensations and movement. Reading a novel, according to lead researcher Gregory Berns, can transport you into the body of the protagonist.
This ability to shift into another mental state is a vital skill that promotes healthy neurogenesis in those areas of the brain.
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Reactive oxygen species (ROS) accumulate in the gut of sleep-deprived fruit flies, one (left), seven (center) and ten (right) days without sleep.
- A study provides further confirmation that a prolonged lack of sleep can result in early mortality.
- Surprisingly, the direct cause seems to be a buildup of Reactive Oxygen Species in the gut produced by sleeplessness.
- When the buildup is neutralized, a normal lifespan is restored.
We don't have to tell you what it feels like when you don't get enough sleep. A night or two of that can be miserable; long-term sleeplessness is out-and-out debilitating. Though we know from personal experience that we need sleep — our cognitive, metabolic, cardiovascular, and immune functioning depend on it — a lack of it does more than just make you feel like you want to die. It can actually kill you, according to study of rats published in 1989. But why?
A new study answers that question, and in an unexpected way. It appears that the sleeplessness/death connection has nothing to do with the brain or nervous system as many have assumed — it happens in your gut. Equally amazing, the study's authors were able to reverse the ill effects with antioxidants.
The study, from researchers at Harvard Medical School (HMS), is published in the journal Cell.
An unexpected culprit
The new research examines the mechanisms at play in sleep-deprived fruit flies and in mice — long-term sleep-deprivation experiments with humans are considered ethically iffy.
What the scientists found is that death from sleep deprivation is always preceded by a buildup of Reactive Oxygen Species (ROS) in the gut. These are not, as their name implies, living organisms. ROS are reactive molecules that are part of the immune system's response to invading microbes, and recent research suggests they're paradoxically key players in normal cell signal transduction and cell cycling as well. However, having an excess of ROS leads to oxidative stress, which is linked to "macromolecular damage and is implicated in various disease states such as atherosclerosis, diabetes, cancer, neurodegeneration, and aging." To prevent this, cellular defenses typically maintain a balance between ROS production and removal.
"We took an unbiased approach and searched throughout the body for indicators of damage from sleep deprivation," says senior study author Dragana Rogulja, admitting, "We were surprised to find it was the gut that plays a key role in causing death." The accumulation occurred in both sleep-deprived fruit flies and mice.
"Even more surprising," Rogulja recalls, "we found that premature death could be prevented. Each morning, we would all gather around to look at the flies, with disbelief to be honest. What we saw is that every time we could neutralize ROS in the gut, we could rescue the flies." Fruit flies given any of 11 antioxidant compounds — including melatonin, lipoic acid and NAD — that neutralize ROS buildups remained active and lived a normal length of time in spite of sleep deprivation. (The researchers note that these antioxidants did not extend the lifespans of non-sleep deprived control subjects.)
Image source: Tomasz Klejdysz/Shutterstock/Big Think
The experiments
The study's tests were managed by co-first authors Alexandra Vaccaro and Yosef Kaplan Dor, both research fellows at HMS.
You may wonder how you compel a fruit fly to sleep, or for that matter, how you keep one awake. The researchers ascertained that fruit flies doze off in response to being shaken, and thus were the control subjects induced to snooze in their individual, warmed tubes. Each subject occupied its own 29 °C (84F) tube.
For their sleepless cohort, fruit flies were genetically manipulated to express a heat-sensitive protein in specific neurons. These neurons are known to suppress sleep, and did so — the fruit flies' activity levels, or lack thereof, were tracked using infrared beams.
Starting at Day 10 of sleep deprivation, fruit flies began dying, with all of them dead by Day 20. Control flies lived up to 40 days.
The scientists sought out markers that would indicate cell damage in their sleepless subjects. They saw no difference in brain tissue and elsewhere between the well-rested and sleep-deprived fruit flies, with the exception of one fruit fly.
However, in the guts of sleep-deprived fruit flies was a massive accumulation of ROS, which peaked around Day 10. Says Vaccaro, "We found that sleep-deprived flies were dying at the same pace, every time, and when we looked at markers of cell damage and death, the one tissue that really stood out was the gut." She adds, "I remember when we did the first experiment, you could immediately tell under the microscope that there was a striking difference. That almost never happens in lab research."
The experiments were repeated with mice who were gently kept awake for five days. Again, ROS built up over time in their small and large intestines but nowhere else.
As noted above, the administering of antioxidants alleviated the effect of the ROS buildup. In addition, flies that were modified to overproduce gut antioxidant enzymes were found to be immune to the damaging effects of sleep deprivation.
The research leaves some important questions unanswered. Says Kaplan Dor, "We still don't know why sleep loss causes ROS accumulation in the gut, and why this is lethal." He hypothesizes, "Sleep deprivation could directly affect the gut, but the trigger may also originate in the brain. Similarly, death could be due to damage in the gut or because high levels of ROS have systemic effects, or some combination of these."
The HMS researchers are now investigating the chemical pathways by which sleep-deprivation triggers the ROS buildup, and the means by which the ROS wreak cell havoc.
"We need to understand the biology of how sleep deprivation damages the body so that we can find ways to prevent this harm," says Rogulja.
Referring to the value of this study to humans, she notes,"So many of us are chronically sleep deprived. Even if we know staying up late every night is bad, we still do it. We believe we've identified a central issue that, when eliminated, allows for survival without sleep, at least in fruit flies."
