keeping human new brain cells

How to keeping human brain cells

So it turns out that your brain is a nursery: every day, it seems, new brain cells are born. But it seems that your brain doesn't always keep these newborn neurons. Just like all other babies, they need special care to survive. And it's not pampering: your newborn neurons, scientists are finding, need to be challenged, exercised, and run hard. 

If you don't use those new cells, they will disappear. Animal research shows that most of these cells die within a couple of weeks unless that brain is challenged to learn something new and, preferably, something hard that involves a great deal of effort. And new is key here as well: just repeating old activities won't support new brain cells.

 Scientists still don't really know why or what the heck the new neurons are doing or even why we make them. Are they made to replace dying cells? One theory is that they are backup, produced just in case they are needed. This idea suggests that your brain calls for reinforcements when new brain cells are available to aid in situations that tax the mind, and that a mental workout can buff up the brain much as physical exercise builds up the body

 In animal studies, scientists found that between five thousand and ten thousand new neurons arise in the rat hipclocampus every day (it's not known how many we humans make, or how often). The birth rate depends on some environmental factors. Heavy alcohol consumption slows the production. for example, whereas exercise increases it. Rats and mice that log time on a running wheel kick out twice as many new cells as do mice that lead a more sedentary life. Even eating antioxidant-rich blueberries seems to goose the generation of new neurons in the rat hippocampus, as do exciting changes in their cages or new toys to pique their interest.

 Elizabeth Gould (a discoverer of neurogenesis in adults), Tracy Stars, and colleagues have been examining the connection between learning and neurogenesis by studying the brains of rats and the importance of hard learning. In their experiments, they first injected the animals with BrdU (bromodeoxyuridine), a drug that marks only brand-new cells. A week later, they recruited half of the treated rats for a training program and let the rest lounge around their home cages. 

The rats enrolled in Rodent University were given an cyeblink course: an animal hears a tone and then, sonic fixed time later (usually 500 milliseconds, or half a second), gets hit in the eye with a puff of air or a mild stimulation of the eyelid, which causes the animal to blink After several hundred trials, the animal learns to connect the tone with the stimulus, anticipate when the stimulus will arrive, and

The birth of brain cells

what you need to know  about neurogenesis

Neurogenesis

We've all heard the warnings: If you (fill in the blank) you'll kill brain cells. And because scientists believed until very recently that you were born with all the brain cells you'd ever have, that was a fairly dire warning. You broke it, and you were stuck with the results.

 Recently we've been able to relax a bit, because we know that our brain makes new cells in at least two sections: the detente Cyrus of the hippocampus, a structure involved in learning and memory, and the olefactory bulbs. And it may in fact create new neurons elsewhere in the brain; we don't know for certain yet.

 Most of this research has been done on animals, but some human studies have confirmed the finding. Studies were done on terminal cancer patients who generously agreed to be injected with a marker for new cell production and to offer their brains for study after their death. The autopsies showed that even in the face of aging and death, their brains continued to produce new neurons to the very end. Chemotherapy could give us an idea of what happens when we don't make new neurons. Chemotherapy impairs the cell division needed for making new cells, and people who have had chemotherapy treatment for cancer and some other serious diseases often complain about a syndrome sometimes referred to as chemobrain. They have trouble with the kinds of learning and remembering that everyone finds challenging, such as juggling multiple projects while trying to process new information. 

Because having a ready supply of new neurons on tap could help to keep your brain intellectually limber, scientists are looking for ways to exploit this to prevent or treat disorders that bring about cognitive decline. Meanwhile, they've found that these new brain cells disappear if you don't use them.

what to need to know about neuroplasticity

neuroplasticity 

 Scientists have long known that the brain can change itself. In fact, your brain is probably changing every microsecond in response to experiences, both external and internal. Those changes come mainly from the growth of new connections and networks among neurons, particularly among newborn neurons.

 We've known that different kinds of experiences lead to changes in brain structure, with more activity in the networks used most. In musicians, for example, the parts of the brain ddclicated to playing their instruments are disproportionately larger than in nonmusicians or in musicians who play a different instrument. A decade-old study of London taxi drivers skilled at navigation in the city center showed the same effect: they had larger hippocampi than nondrivers, reflecting the huge amount of data they needed to have at hand. Moreover, the longer they drove complicated routes around the city, the larger their hippocampi grew.

 Also, brains apparently riddled with blank areas or plaque and other signs of Alzheimer's disease have come from people functioning very well into late old age. Indeed, some brains lacking a hemisphere—the entire half of a brain—can function quite well.

 We also know the brain can sometimes repair itself after devastating injury, bypassing dead areas to create new connections. ABC news correspondent Bob Woodruff, critically injured by a roadside bomb in 2006 while covering the war in Iraq, suffered a brain injury so severe that part of his skull was permanently removed, and he was kept in a medically induced coma for more than a month. Few believed he would walk again, let alone work as a reporter. After more than a year of intensive therapy, which included relearning speech to

what is important or reasons to take care of human brain

 Centenarians—individuals one hundred years or older—are the fastest growing age group in the United States, and experts predict there may be as many as 1 million by 2050.

 If you're sixty years old (or younger) today, you could be in that group. And if you want your mind to be there along with you, take good care of your brain.

 You'll have plenty of company near your age: people aged eighty and older are the fastest-growing portion of the total population in many countries. By 2040, the number of people sixty-five or older worldwide will hit 1.3 billion, according to the National Institute on Aging, which announced the figures. And within ten years, there will be more people aged sixty-five and older than children under five in the world for the first time in human history.

 The most rapid increase will be in developing countries. By 2040, they will be home to more than 1 billion people aged sixty-five and over-76 percent of the projected world total. If you reach one hundred years, you are sure to live in interesting times, an old blessing (or curse) of the Chinese (who, incidentally, will have the world's largest population of elders by 2040). This global aging will change the social and economic nature of the planet and present some difficult challenges. Interesting times, indeed.

overcome aphasia, he made a hard-hitting documentary about the plight of injured soldiers and the deficits in government care. And then he went back to work as a reporter—in Iraq. Certainly Woodruff benefited from the kind of very expensive and intense treatment not available to all of us. Nevertheless, his recovery shows how remarkably able the brain is, especially because his was not a young brain: he was forty-four at the time of his injury. What we did not know for certain until recently is that what you think and feel also physically change your brain, such as intellectual

challenges, deliberate brain training, anxiety, and joy. So it seems there is a biological basis to mind training: you can learn skills aimed at changing your brain just as you learn repeated activities to change your body. Meditation is a brain-changing example. Studies show that regular practice of meditation results in physical as well as mental and emotional changes. In long-time practitioners of meditation, the two hemispheres become more balanced, the trigger-happy amygdala shows less reaction to emotional sounds, and the many brain regions involved in focused attention show greater activity (see "Boosting Your Brain with Meditation," p. 31).

How to changes in human brain 

Epigenetics 

Scientists are finding one of the ways your brain changes itself is by actually changing your genes—or more correctly, by the acting out (or not) of certain genes—in the process of epigenesis. We know that your genome is the total deoxyribonucleic acid (DNA) that you inherit from your ancestors and contains the instructions for making your unique body and brain. Another layer of information, called the epigenome, is stored in the proteins and chemicals that surround and stick to the DNA. It's a kind of chemical switch that determines which genes are activated (or not): it tells your genes what to do and where and when.

Researchers have discovered that the epigenome can be affected by many things, from aging and diet to environmental toxins to even what you think and feel. This means that even your experiences can literally change your mind by chemically coating the DNA that con
trols a function. The coating doesn't alter the underlying genetic code; rather, it alters specific gene expression, shutting down or revving up the production of proteins that affect your mental state.

 Epigenetics helps explain the gap between nature and nurture that has long puzzled scientists: why some illnesses and traits pop up in one but not both identical twins who have the same DNA, or why these traits skip a generation. It also helps explain neuroplasticity.

One researcher describes DNA as a computer hard disk, with certain areas that are password protected and others that are open. Epigenetics is the programming that accesses that material, writes Jolt Walter of Saarland, Germany, on the Web site Epigenome. 

Epigenetics can profoundly affect your health and, it seems, your happiness, changing not only your vulnerability to some diseases such as cancer but also your mental health. Scientists have found, for example, that a mother rat's nurturing, through licking and loving behavior that boosts the expression of a gene that eases anxiety and stress, bolsters emotional resilience in her newborn pups. They've also found that distressing events can turn off the expression of genes for brain cell growth protein and thereby trigger depression, and that epigenetic changes may also underlie the pathology of schizophrenia, suicide, depression, and drug addiction. 

The acting-out process of changeable genes—gene expression—is quite complicated and a new area of intense research. Just recently biologists have found that epigenetic changes may be heritable—passed on to your descendants—just as your DNA is. They have also found that altering gene expression with drugs or environments that provide more intellectual stimulation can improve learning and memory in cognitively impaired animals. Future therapies for memory disorders in humans might work in a similar way. It's a promising area with much to be learned. In 2008, the National Institutes of Health invested $190 million in the five-year Roadmap Epigenomics Program to pursue some of these promising fields of research.

Human changeable brain

what is the changeable brain

When you woke up today, you were a new person literally. Many of the cells in your body had replaced themselves with younger versions, and your brain has been busy as well. Scientists have discovered your brain is a work in process. Every day, it seems, your brain makes new neurons in at least some sections, and almost every second, your brain is changing its networking in response to what you experience, think, feel, and need. In fact, your brain can even direct changes to some of your genes, turning them off or on.

Then Your brain is hardwired and unchangeable, and you're born with all the brain cells you'll ever have. Good luck, because when they're gone, they're gone.

 NOW: Who knew? Your brain creates new neurons in some areas and new networks, even into old age, and it changes physically in response to your actions, thoughts, and emotions. Your genes are not your destiny—or at least not all of it.

 Tomorrow: Well be able to direct changes: stimulate new brain cells and networks where and when we need them; turn genes off and on at will to repair brain damage, restore function, and optimize performance; and rewire our brains to manipulate memory and even reverse dementia and mental retardation.

 The revolutionary findings about your brain's remarkable ability to change itself are barely a decade old. Biologists had long believed that the creation of brain cells was completed at or shortly after birth, and that the rest of your life was a slow slide into brain cell loss. In the 1990s, scientists rocked the field of neurobiology with the startling news that the mature mammalian brain is capable of sprouting new neurons in the hippocampus and the ole factory bulbs, and that it continues to do so even into old age. This process is called neurogenesis.

 Scientists also confirmed what was long suspected: your brain is not hardwired. It can reinvent itself, as it were, by creating new path-ways to reroute, readjust, and otherwise change the networking and connections, sometimes even substituting one area for another. When one part of your brain goes south—from a stroke or trauma, for exampleother sections can sometimes take over some of those functions. Your brain also changes to reflect what you learn, do, and think. In fact, your brain is physically rearranging its networks just about every minute of every day. That's neuroplasticity.

 Then they discovered that your actions, thoughts, feelings, or environment can change your genes—more specifically, whether certain genes are expressedaltering brain function; character traits; and risk of some diseases, from cancer to schizophrenia. That's epigenetics.

brain science is a big business

why important the brain science

In fact, it has spawned a whole new industry. Three hot neurotech areas that promise major changes in brain research in the near future are neuroimaging, neuropharmacology, and neurodevices such as brain implants. And they are thriving. The Neurotechnology Industry Report for 2008 shows 2 billion people worldwide suffering from a brain-related illness, with an annual economic burden of more than $2 trillion. Globally, in 2008, more than 550 public and private companies participated in a neurotech industry where revenues rose 9 percent to $144.5 billion overall, with neuropharmaceuticals reporting earnings of $121.6 billion, neurodevices revenues of $6.1 billion, and neurodiagnostics revenues of $16.8 billion.

 The military has a hefty investment in this as well. Neurotechnology and research will help the thousands of soldiers returning from wars with severe brain injuries or missing limbs. Advances will also perfect the toolbox for warfare. Neuroenhancers will keep soldiers and fighter pilots awake and alert for days, and will fine-tune and juice up mental focus and reflexes. Brain-machine interfaces could create new weapons and allow exploration into deep space and other hostile territory. And neuroimaging could allow us to see into brains to predict and possibly control behavior and thoughts.

How your brain works the short version

A refresher on brain basics will help set the context for the detailed chapters that follow. Your brain is three pounds of flesh, nerves, and fluid that looks like a big walnut but is much softer. Its billion or so specialized cells called neurons communicate and form networks through chemicals (especially those called neurotransmitters) and minuscule electrical charges that pass over the tiny gaps, or synapses, between them. The overall brain is often described in three parts: the primitive brain, the emotional brain, and the thinking brain.

  The primitive brain

 the brain stem or hindbrainsits at the top of the spine and takes care of the automated basics, such as breathing, heartbeat, digestion, reflexive actions, sleeping, and arousal. It includes the spinal cord, which sends messages from the brain to the rest of the body, and the cerebellum, which coordinates balance and rote motions, like riding a bike and catching a ball. Above this, your brain is divided into two similar, but not identical, hemispheres connected by a thick band of fibers and nerves called the corpus callosum. Each side functions slightly differently than the other does, and for reasons not yet understood, the messages between the hemispheres and the rest of our body crisscross, so that the right brain controls our left side and vice versa.

 The emotional brain

The emotional brain, or limbic system, is tucked deep inside the bulk of the mid brain and acts as the gatekeeper between the spinal cord and the thinking brain in the cerebrum above. It regulates survival mechanisms such as sex hormones; sleep cycles; hunger; emotions; and, most important, fear, sensory input, and pleasure. The amygdala is our sentry, the hippo campus is the gateway to short-term memory, and the hypothalamus controls your biological clock and hormones, while the thalamus passes along sensory information to the thinking centers in the cortex above. The basal ganglia surround the thalamus, and are responsible for voluntary movement. The so-called pleasure center, or reward circuit, is also based in the limbic system, involving the nucleus accumbens and ventral tegmental area.

 the thinking brain

The thinking brain the part we usually see when we picture a brain and what is sometimes called the crown jewel of the body—sits on the top, where it controls thoughts, reasoning, language, planning, and imagination. Vision, hearing, speech, and judgment reside here as well. But let's be honest. In spite of enormous research advances, scientists still have a pretty rudimentary understanding of brain function and how it relates to your thoughts, feelings, and actions. There are frequent announcements about how the sources of some emotions and functions have been "mapped" in the brain, but most of these should be qualified: brain researchers are still trying to figure out much of what goes on between your ears. But they're gaining on it.

the process of brain

why important of brain for human

introduction of brain

We know more about the brain today than ever before, and a perfect storm of events is supporting even more and better brain knowledge and better brains.

There is a tremendous surge of research on the brain and tremendous pressure to learn more, and learn it faster, from an aging generation with the will and the means to force these advances: boomers.

The first of the boomers, the largest ever demographic group and (even with the recession) the best off financially, are hitting old age, and a group that never took no for an answer is not going gently into that good night; instead, it is kicking, screaming, and raging for a better aging brain. Billions are being expended on brain research, especially in areas related to dementia, memory loss, and other conditions of aging.

The National Institutes of Health (NIH) alone spent $5.2 billion, nearly 20 percent of its total budget, on brain-related projects in 2008. With this expanded funding, researchers are making sweeping inroads in both understanding and manipulating the brain.

We've learned more about the brain in the past fifty years than the preceding fifty thousand, and the cooperation among the sciences over the next two decades may even surpass that record. Brain research has moved beyond psychology, psychiatry, and neurology, and married the so-called wet and hard sciences: biology, biochemistry, and chemistry now cohabit with physics, engineering, electronics, computer science, material sciences, statistical analysis, and even information technologies, with advances

 in technology contributing ever-better, smaller, faster, and smarter devices and techniques. Scientists and futurists are predicting what will have changed by mid century:

• Computer chips or mini-microprocessors in the brain will expand memory; control symptoms of brain disease, from Parkinson's disease to depression and anxiety; and wireless receive and transmit information so that you won't need a cell phone or a computer to stay in touch.

• Brain surgery will be a thing of the past except in the most severe cases. Advanced neurhimaging will identify mental illness and brain disease before symptoms show and in general be used to "read" minds and predict and control behavior. Microscopic robots—nanobots—will enter your bloodstream to diagnose and repair brain damage. Protein molecules will travel your brain in a similar way to turn on or off brain cells or genes responsible for brain diseases.

• Neurohenhancers from drugs to digital devices will boost memory and mind function in healthy people—and equally powerful drugs will help block painful or traumatic memories. That could mean growing new brain cells to replace neurons damaged by disease or slipping your kids a memory pill while they cram for Advanced Placement calculus.

• Alzheimer's disease, other dementias, and perhaps even mental retardation will be preventable, curable, and even reversible in many people.

• Those who are paralyzed will regain limb and spinal cord function, and thought-driven spare parts will abound, from prosthetic limbs and vision with lifelike function to prosthetic brain chips to store data and perhaps even duplicate neural networks.