Neuroplasticity: The brain’s ability to reorganize itself by forming new neural connections throughout life. Neuroplasticity allows the neurons (nerve cells) in the brain to compensate for injury and disease and to adjust their activities in response to new situations or to changes in their environment.
Brain reorganization takes place by mechanisms such as “axonal sprouting” in which undamaged axons grow new nerve endings to reconnect neurons whose links were injured or severed. Undamaged axons can also sprout nerve endings and connect with other undamaged nerve cells, forming new neural pathways to accomplish a needed function.
Scientists once thought that the brain stopped developing after the first few years of life. They thought that connections formed between the brain’s nerve cells during an early “critical period” and then were fixed in place as we age. If connections between neurons developed only during the first few years of life, then only young brains would be “plastic” and thus able to form new connections.
Because of this belief, scientists also thought that if a particular area of the adult brain was damaged, the nerve cells could not form new connections or regenerate, and the functions controlled by that area of the brain would be permanently lost. However, new research on animals and humans has overturned this mistaken old view: today we recognize that the brain continues to reorganize itself by forming new neural connections throughout life. This phenomenon, called neuroplasticity, allows the neurons in the brain to compensate for injury and adjust their activity in response to new situations or changes in their environment.
How does neuroplasticity work? A large amount of research focuses on this question. Scientists are certain that the brain continually adjusts and reorganizes. In fact, while studying monkeys, they found that the neuronal connections in many brain regions appear to be organized differently each time they are examined! Existing neural pathways that are inactive or used for other purposes show the ability to take over and carry out functions lost to degeneration, and there is evidence that reorganization in the adult brain can even involve the formation of new neural connections. Understanding the brain’s ability to dynamically reorganize itself helps scientists understand how patients sometimes recover brain functions damaged by injury or disease.
Neurons and Neurogenesis^
Billions of tree-shaped nerve cells make up the human brain. Neurons are produced through a process called neurogenesis, which begins during the third week of development in humans. Nerve cells develop at an average rate of 250,000 per minute during the prenatal period, but by birth, the process ofneurogenesis has largely ceased. (To read more about neurons, click here.)
A widely held belief is that neurons, unlike other cells, cannot reproduce after the first few years of life. This would mean that neurons that are destroyed couldn’t be replaced. However, recent research suggests that this belief is not supported by evidence. In 1999, production of new neurons was discovered in theneocortex of adult primates. Also in 1999, researchers at the Salk Institute in San Diego, California discovered neurogenesis occurring in the brains of adult humans, including in a 72-year-old adult. In this study, researchers used a chemical marker to identify new neurons and observed neurogenesis in thehippocampal region, a brain region that controls certain types of memory.
This research indicates that neurogenesis may well continue to occur throughout the human life span, although it occurs less rapidly in adults. Many of the new neurons that form in adults die almost immediately, but evidence suggests that some cells that are able to integrate themselves into the existing web of neural connections. Other researchers have also found definitive evidence that the brain does not stop producing new neurons after the “critical period” of development; the brain has been shown to generate new neurons from stem cells in select regions of the brain.
(NaturalNews) Prior to about 20 years ago, it was believed that the human brain was incapable of producing new brain cells after reaching maturity. But scientists now widely accept the fact that the human brain canundergo neurogenesis, in which new neurons are born, even into adulthood, and that this process can be helped along through certain dietary and lifestyle changes.
Two specific regions of the brain, the subventricular zone and the hippocampus, both show evidence of neurogenesis post-maturity. The latter region is responsible for learning and memory, and when it’s not functioning as it should, neurodegenerative conditions like depression, anxiety and Parkinson’s can ensue. But you can help reduce your risk while simultaneously promoting adult-stage brain cell formation by following these five steps:
1) Exercise. It might sound cliche, but the single most effective way to promote neurogenesis in your brain is to exercise regularly. Getting your heart pumping and your blood flowing by running, biking, or swimming is a great way to increase levels of brain derived neurotrophic factor (BDNF) and glial cell line-derived trophic factor (GDNF), two key growth factors that promote neurogenesis.
The endorphins released through cardiovascular exercise also help minimize levels of cortisol, a stress hormone, while increasing levels of the hormone testosterone, which like BDNF and GDNF helps promote neurogenesis. These exercise-induced hormones and growth factors are especially critical as a person ages, since they act as anti-aging, cognition-boosting nutrients.
2) Meditation. The scientific benefits of meditation are well-established, and you don’t necessarily have to be religious to derive benefits from it. A growing body of evidence suggests that meditation can help increase the gray matter density of various regions of the brain, including the hippocampus.
By helping individuals to focus more on the now rather than the past and future, meditation clears the mind and helps balance brain chemicals, including those that regulate neurogenesis. At least one study determined that meditation helps activate certain integrative functions in the brain, promoting both short- and long-term neural changes.
Night meditation can also help up-regulate the body’s production of melatonin, a sleep hormone directly linked to neurogenesis. Amishi Jha from the University of Miami recommends “mindfulness-based mind-fitness training,” a method that involves focusing on a specific object, such as a particular body sensation, in order to improve brain structure and function, and ultimately one’s intelligence.
3) Diet. Eating right might seem obvious, but many people still don’t know what this means. Your brain is made up of about 60 percent fat, which necessitates that fat plays an important role in everyday nutrition. But many people still view fat as bad, seeking to avoid it in favor of fat-free or low-fat food options packed with chemical sweeteners and other artificial flavor additives.
Omega-3 fatty acids are an important fat to consume regularly for improved brain health, as are healthy saturated fats like coconut and palm oil. Docosahexaenoic acid in particular is a critical fat component that, as it pertains to neurogenesis, is absolutely necessary forthe brain to manufacture new brain cells.
4) Sleep, sunlight and sex. It doesn’t get nearly the credit it deserves, but sleep is critical for healthy brain function. Sleep deprivation, it turns out, reduces hippocampal neurogenesis, throwing hormone balance out of whack and cluttering the brain. A recent study published in the journal Current Topics in Behavioral Neurosciences found that sleep disruptions exceeding 24 hours inhibit cell proliferation, and in some cases neurogenesis.
Natural exposure to sunlight is another factor in neurogenesis, as vitamin D, which is produced when unblocked skin is exposed to the sun’s rays, increases levels of both serotonin (a brain neurotransmitter) and GDNF expression in the brain. Optimal exposure to beneficial ultraviolet (UV) rays from the sun ranges between 10 and 15 minutes during the summer months.
And then there’s sex, which helps reduce stress while boosting levels of certain “feel-good” transmitters in the brain. A 2010 study published in the journal PLoS ONE found that sex helps minimize both anxiety and corticosterone levels while promoting adult neurogenesis and stimulating the growth of dendritic spines and architecture in the hippocampus.
5) Psilocybin and cannabis. Various psychoactive compounds, including those found in “magic” mushrooms (psilocybin) and cannabis (THC and CBD), have also been shown to aid in the development of new brain cells. Psilocybin, it turns out, both increases hippocampal neurogenesis and increases the ability of the brain to “unlearn” certain negative fear responses, hence why sufferers of post-traumatic stress disorder (PTSD) often report benefits from supplementing with psilocybin.
And cannabis, which is increasingly legal throughout the U.S., possesses compounds like tetrahydrocannabinol (THC) and cannabidiol (CBD) that match with receptors in the brains to reduce anxiety and promote neurogenesis. High Existence has published a more thorough listing of beneficial psychoactive compounds that can aid in promoting brain cell growth, which you can access here: highexistence.com