Posts Tagged stem cells

[VIDEO] Why Can’t WE Reverse Nerve Damage ? – Reversing Nerve Damage: Central Nervous System Inhibits Cell Regeneration, But Stem Cell Treatment May Help

 

Our nervous system is involved in everything our body does, from maintaining our breath to controlling our muscles. Our nerves are vital to all we do; therefore, nerve pain and damage can heavily influence our quality of life. In Discovery News’ latest video, “Why Can’t We Reverse Nerve Damage?” host Lissette Padilla explains the central nervous system (CNS) has certain proteins that inhibit cell regeneration, because each cell in the nervous system has a unique function on the pathway, like a circuit, and can’t be replaced.

The nervous system can be divided into two sections, with the brain and spinal cord making up the CNS. Nerves are made up of sensory fibers and motor neurons, which comprise the peripheral nervous system. Nerve cells are made up of many parts, but they send signals through threads covered in a protective sheet of myelin. These threads are called axons.

Axons are the long part of the cell that reaches out to neighboring cells to send information down the line. Schwann cells, found only in the peripheral nervous system, are glial cells that produce protective myelin. Schwann cells could potentially clean up damaged nerves, which could make way for healing process to take place and new nerves to be formed.

The problem is these Schwann cells are missing from the CNS. The CNS is comprised of myelin-producing cells called oligodendrocytes. And these cells don’t clean up damaged nerve cells at all, hence the damage problem.

However, research is currently underway to examine the potential success of system cell treatment, where stem cells are injected directly at the injury site. It will still take a few years to see the results of such trials, but since the peripheral nervous system doesn’t have the same blocking proteins that the CNS has, the idea is Schwann cells could help heal the damage.

So it is possible to regrow nerves, albeit slowly. For instance, if you cut a nerve into your shoulder, it could take a year to regrow. By that time, the muscles in your arms could become atrophied. Researchers are working on helping the body heal faster.

Source: Reversing Nerve Damage: Central Nervous System Inhibits Cell Regeneration, But Stem Cell Treatment May Help

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[Thesis] The road to optimized nerve reconstruction by Caroline A. Hundepool, 2016 – Full Text PDF

1. Introduction

Peripheral nerve injuries are devastating injuries, which can lead to severe disability. Nerve injuries are relatively common. It occurs with up to 3% of all patients admitted to Level I trauma centers. Most of the injuries to peripheral nerves occur in the upper extremities. Nerve injury will lead to significant impairment in motor function and causes sensory loss. Depending on the level of nerve injury the consequences can be devastating and have great impact on a patient’s life and ability to perform daily activities such as work and hobbies. Nerve injury not only causes physical disability. There is evidence it also has great consequences psychologically. Cognitive, emotional and behavioral aspects influence recovery. It is important these factors are recognized so that the quality of patient care can be improved[1]. The last decades both experimental and clinical research has been focused on optimizing the reconstruction of nerve injuries. The studies in this thesis are focused on the optimization of nerve reconstruction.

Full Text PDF

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[WEB SITE] Scientists discover neuron-producing stem cells in the membranes covering the brain

Credit: Heidi Cartwright, Wellcome Images

 

Discovery brings with it possible implications for brain regeneration –

In a cross-domain study directed by professor Peter Carmeliet (VIB – KU Leuven), researchers discovered unexpected cells in the protective membranes that enclose the brain, the so called meninges. These ‘neural progenitors’ (stem cells that differentiate into different kinds of neurons) are produced during embryonic development.

See Also: Stem cells in the brain: Limited self-renewal

These findings show that the neural progenitors found in the meninges produce new neurons after birth, highlighting the importance of meningeal tissue as well as these cells’ potential in the development of new therapies for brain damage or neurodegeneration. A paper highlighting the results is published in the journal Cell Stem Cell.

Scientists’ understanding of brain plasticity, or the ability of the brain to grow, develop, recover from injuries and adapt to changing conditions throughout our lives, has been greatly broadened in recent years. Before the discoveries of the last few decades, neurologists once thought that the brain became ‘static’ after childhood. This dogma has changed, with researchers finding more and more evidence that the brain is capable of healing and regenerating in adulthood, thanks to the presence of stem cells. However, neuronal stem cells were generally believed to only reside within the brain tissue, not in the membranes surrounding it.

The meninges: unappreciated no more

Believed in the past to serve a mainly protective function to dampen mechanical shocks, the meninges have been historically underappreciated by science as having neurological importance in its own right. The data gathered by the team challenges the current idea that neural precursors—or stem cells that give rise to neurons—can only be found inside actual brain tissue.

Learn More: Scientists sniff out unexpected role for stem cells in the brain

Prof. Peter Carmeliet notes: “The neuronal stems cells that we discovered inside the meninges differentiate to full neurons, electrically-active and functionally integrated into the neuronal circuit. To show that the stem cells reside in the meninges, we used the extremely powerful single-cell RNA sequencing technique, a very novel top-notch technique, capable of identifying the [complex gene expression signature] nature of individual cells in a previously unsurpassed manner, a première at VIB.”

Following up on future research avenues

When it comes to future leads for this discovery, the scientists also see possibilities for translation into clinical application, though future work is required.

“An intriguing question is whether these neuronal stem cells in the meninges could lead to better therapies for brain damage or neurodegeneration. However, answering this question would require a better understanding of the molecular mechanisms that regulate the differentiation of these stem cells,” says Carmeliet. “How are these meningeal stem cells activated to become different kinds of neurons? Can we therapeutically ‘hijack’ their regeneration potential to restore dying neurons in, for example, Alzheimer’ Disease, Parkinson’s Disease, amyotrophic lateral sclerosis (ALS), and other neurodegenerative disorders? Also, can we isolate these neurogenic progenitors from the meninges at birth and use them for later transplantation? These findings open up very exciting research opportunities for the future.”

Moving into unchartered territory is high risk, and can offer high gain, but securing funding for such type of research is challenging. However, Carmeliet’s discoveries were made possible to a large extent by funding through “Opening the Future: pioneering without boundaries”, a recently created Mecenas Funding Campaign for funding of high risk brain research but with potential for breakthrough discoveries, started up by the KU Leuven in 2013 and unique in Flanders.

Read Next: A better way to grow motor neurons from stem cells

“Being able to use such non-conventional funding channels is of utmost importance to break new boundaries in research,” says Carmeliet. “This unique Mecenas funding initiative by the KU Leuven is innovative and boundary-breaking by itself. Our entire team is enormously grateful for the opportunities it has created for our investigations”.

Note: Material may have been edited for length and content. For further information, please contact the cited source.

VIB – Flanders Institute for Biotechnology   press release

Publication

Bifari F et al. Neurogenic Radial Glia-like Cells in Meninges Migrate and Differentiate into Functionally Integrated Neurons in the Neonatal Cortex.   Cell Stem Cell, Published Online November 23 2016. doi: 10.1016/j.stem.2016.10.020

Source: Scientists discover neuron-producing stem cells in the membranes covering the brain

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[VIDEO] What are stem cells, and why are they important – YouTube

 

What are stem cells, and why are they important?

Stem cells have the remarkable potential to develop into many different cell types in the body during early life and growth. In addition, in many tissues they serve as a sort of internal repair system, dividing essentially without limit to replenish other cells as long as the person or animal is still alive. When a stem cell divides, each new cell has the potential either to remain a stem cell or become another type of cell with a more specialized function, such as a muscle cell, a red blood cell, or a brain cell.

Stem cells are distinguished from other cell types by two important characteristics. First, they are unspecialized cells capable of renewing themselves through cell division, sometimes after long periods of inactivity. Second, under certain physiologic or experimental conditions, they can be induced to become tissue- or organ-specific cells with special functions. In some organs, such as the gut and bone marrow, stem cells regularly divide to repair and replace worn out or damaged tissues. In other organs, however, such as the pancreas and the heart, stem cells only divide under special conditions.

Until recently, scientists primarily worked with two kinds of stem cells from animals and humans: embryonic stem cells and non-embryonic “somatic” or “adult” stem cells. The functions and characteristics of these cells will be explained in this document. Scientists discovered ways to derive embryonic stem cells from early mouse embryos more than 30 years ago, in 1981. The detailed study of the biology of mouse stem cells led to the discovery, in 1998, of a method to derive stem cells from human embryos and grow the cells in the laboratory. These cells are called human embryonic stem cells. The embryos used in these studies were created for reproductive purposes through in vitro fertilization procedures. When they were no longer needed for that purpose, they were donated for research with the informed consent of the donor. In 2006, researchers made another breakthrough by identifying conditions that would allow some specialized adult cells to be “reprogrammed” genetically to assume a stem cell-like state. This new type of stem cell, called induced pluripotent stem cells (iPSCs), will be discussed in a later section of this document.

Stem cells are important for living organisms for many reasons. In the 3- to 5-day-old embryo, called a blastocyst, the inner cells give rise to the entire body of the organism, including all of the many specialized cell types and organs such as the heart, lungs, skin, sperm, eggs and other tissues. In some adult tissues, such as bone marrow, muscle, and brain, discrete populations of adult stem cells generate replacements for cells that are lost through normal wear and tear, injury, or disease.

Given their unique regenerative abilities, stem cells offer new potentials for treating diseases such as diabetes, and heart disease. However, much work remains to be done in the laboratory and the clinic to understand how to use these cells for cell-based therapies to treat disease, which is also referred to as regenerative or reparative medicine.

Laboratory studies of stem cells enable scientists to learn about the cells’ essential properties and what makes them different from specialized cell types. Scientists are already using stem cells in the laboratory to screen new drugs and to develop model systems to study normal growth and identify the causes of birth defects.

Research on stem cells continues to advance knowledge about how an organism develops from a single cell and how healthy cells replace damaged cells in adult organisms. Stem cell research is one of the most fascinating areas of contemporary biology, but, as with many expanding fields of scientific inquiry, research on stem cells raises scientific questions as rapidly as it generates new discoveries.

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[BLOG POST] Exciting research suggests the brain can repair itself – with help

BY: SOPHIA VOUMVAKIS

In June of last year I wrote a post entitled Can the Brain Repair Itself? The answer to this question according to research conducted by Dr. Siddharthan Chandran, director of the Centre for Clinical Brain Sciences, is “Yes, just not well enough.”

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photo credit: SumaLateral Whole Brain Image via photopin (license)

In 2013, Dr. Chandran and his associates were able to extract stem cells from the bone marrow of patients with Multiple Sclerosis, use these stem cells to grow myelin cells – damage of myelin cells is associated with diseases such as Multiple Sclerosis (MS) – and then inject these cultured myelin cells back into the patient’s veins. To measure whether the intervention was successful, the scientists examined the optic nerve. The size of the optic nerve was measured before the injection of the lab grown myelin cells, three and six months post injection (patients with MS usually have vision problems). Results showed the optic nerve had stopped shrinking, which Dr. Chandran believes is the result of the injected myelin cells. These cells promoted the brain’s own stem cells to do their job of laying down more myelin.

In December 2015, neurosurgeon Dr. Jocelyne Bloch gave a TED talk entitled The Brain May Be Able To Repair Itself With Help. In this research, Dr. Bloch, along with Dr. Jean-Francois Brunet were able to culture cells from pieces of swollen brain tissue that had been removed from patients with brain trauma in order to reduce intracranial pressure.

What they discovered, after many failed attempts to grow cells from these pieces of brain tissue, is that under the microscope, these cells looked very much like stem cells. Stem cells are immature cells that we can grow into any other type of cell. Remember, Dr. Chandran and his colleagues were able to grow myelin cells from a patient’s own stem cells.

The culture that Drs. Bloch and Brunet had grown was however somewhat different from other stem cells – they looked like stem cells, but behaved differently. This new cell population was not as active as other stem cells, that is, they divided less rapidly, and unlike other stem cells, they died. The stem cells came from doublecortin-positive cells, which make up four per cent of our cortical brain cells and during our fetal development doublecortin-positive cells facilitate our brain folding itself.

Drs. Bloch and Brunet postulated that doublecortin-positive cells may promote brain repair because they found a higher concentration of these cells in areas of brain lesions. This observation is a correlation, not a cause and effect. So, the scientists designed an experiment to demonstrate that these stem cells derived from doublecortin-positive cells do indeed promote brain repair. The experimental design that Drs. Bloch and Brunet created involved the biopsy of cortical cells, culturing these cells, labelling the cultured cells and re-injecting the cultured cells into the same individual.

Working with professor Eric Rouller, from the University of Fribourg, Switzerland, Drs. Bloch and Brunet re-implanted the cultured stem cells into the a healthy monkey’s brain. What they observed several weeks later, was that the re-implanted stem cells had completely disappeared. Dr. Bloch postulates that the cells were not needed, as there was no damage, and simply went somewhere else. However, when these cultured stem cells were re-implanted into the brain of a monkey with a lesioned brain, the cultured stem cells remained and became mature neurons!

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photo credit: Marmoset embryonic stem cells forming neurons via photopin(license)

The next question posed by Drs. Bloch and Brunet was – “can these cells help a monkey after a lesion?” The scientists trained monkeys to perform a manual dexterity task – picking pellets of food off a tray. Once the monkeys had reached a plateau of performance, the scientists lesioned a section of the motor cortex that corresponds to the hand motion that the monkeys had been trained to perform. The monkeys were rendered pelagic, they could not move their hands anymore.

As with humans, the monkeys did, in time, spontaneously recover to a certain extent, due to the neuroplasticity of the brain. When the scientists were confidant that the monkeys had reached their plateau of spontaneous recovery, they re-implanted its’ own cultured cortical cells.

The monkey that had spontaneously recovered, and had not had its’ cultured cortical cells reimplanted, performed the task at about 40 -50% of his previous performance – not particularly accurate, and not too quick. The monkey with the re-implanted stem cells? Two months later, same performance as before the lesion!

Since then scientists have learned a lot more about these cells – they have been able to cryopreserve them for future use, and they have used them to treat other neuropathologies, such as Parkinson’s Disease. The next step is to go to human trials – a long, complicated and arduous process. I am optimistic that these brilliant scientists will one day get there and there will come a day when we will see the use of our own brain cells in the treatment of neuropathology’s in humans.

Since her TBI in 2011, Sophia has educated herself about TBI. She is interested in making research into TBI accessible to other survivors.

Source: Exciting research suggests the brain can repair itself – with help

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[WEB SITE] Clinical study to evaluate safety of investigational cell therapy to treat chronic motor deficits after stroke.

University Hospitals Case Medical Center is the first surgical site for a Phase 2b clinical trial study to further evaluate the safety and efficacy of an investigational cell therapy for the treatment of chronic motor deficit following an ischemic stroke.

“With strokes, focus has been on prevention or treatment within the first few hours,” said Jonathan Miller, MD, Director of the Center for Functional and Restorative Neurosurgery at UH Case Medical Center and Assistant Professor of Neurosurgery at Case Western Reserve University School of Medicine, who performs the stem cell surgery as part of the study. “Stroke is the leading cause of adult disability in the U.S., and there really hasn’t been much for this patient population.”

Ischemic strokes account for approximately 87 percent of all strokes in the US and occur when there is an obstruction in a blood vessel supplying oxygen to the brain. With approximately 800,000 strokes occurring in the United States every year, stroke is the leading cause of acquired disability in the United States. Traditional stroke treatments generally show little or no improvement in patients after the first six months following a stroke.

The ACTIsSIMA “Allogeneic Cell Therapy for Ischemic Stroke to Improve Motor Abilities” trial will examine the effects of genetically modified adult bone-marrow-derived stem cells in patients who have experienced an ischemic stroke in the previous six months to five years and still suffer from motor impairments.

Dr. Miller said, “For the hundreds of thousands of people living with the debilitating effects of ischemic stroke, the ACTIsSIMA trial will help determine whether this investigational cell therapy is a safe and effective treatment option.”

The Phase 2b clinical trial follows a previous open label Phase 1/2a clinical trial in a similar patient population. The Phase 2b study will further evaluate the safety and efficacy of the treatment in a blinded and controlled setting.

The study will enroll 156 patients with chronic motor deficits after stroke. They are being recruited through 50 assessment sites throughout the United States. Patients will range in age from 18 to 75 years of age. Once enrolled through an assessment site, patients will come to one of 18 surgical sites such as UH Case Medical Center, for the injection of cells. The patient will then be monitored for the duration of the study at the assessment sites. The closest assessment sites to UH are in Toledo and Detroit.

The ACTIsSIMA trial will further evaluate the safety and efficacy of intracranial administration of modified adult bone-marrow-derived stem cells when administered to patients with chronic motor deficit secondary to ischemic stroke.

“UH Case Medical Center has been in the forefront of adult stem cell research,” said Dr. Miller. “We are excited to be part of this study to evaluate the potential of this treatment for stroke. Although it will take time, this study and others involving stem cells, may lead to new methods of helping patients.”

Source: University Hospitals Case Medical Center

Source: Clinical study to evaluate safety of investigational cell therapy to treat chronic motor deficits after stroke

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[TED Talk] Jocelyne Bloch: The brain may be able to repair itself – with help

Through treating everything from strokes to car accident traumas, neurosurgeon Jocelyne Bloch knows the brain’s inability to repair itself all too well. But now, she suggests, she and her colleagues may have found the key to neural repair: Doublecortin-positive cells. Similar to stem cells, they are extremely adaptable and, when extracted from a brain, cultured and then re-injected in a lesioned area of the same brain, they can help repair and rebuild it. “With a little help,” Bloch says, “the brain may be able to help itself.”

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[Blog Post] Can the brain repair itself?

JUNE 29, 2015 ~ BRAIN INJURY BLOG TORONTO

BY: SOPHIA VOUMAKIS

When I suffered my traumatic brain injury (TBI) in 2011, I believed that the cells in my brain which had been damaged were irreparable. But recent research suggests that the brain can repair itself, and that what was once damaged may be able to heal.

Before we explore the scientific evidence, we need to have a rudimentary understanding of how the brain works. Very simply, the brain is made up of two main groups of cells, neurons and glial. When these cells work together, the electrical activity they create enables us to move, think, emote, feel, remember – essentially, to live.

"Human neural stem cells (shown in red), originally reprogrammed from adult skin cells, differentiate efficiently into brain cells (shown in green), after being cultured with star-shaped cells called astrocytes." Photo credit:  Chen Lab, Penn State University via Pen State NewsHuman neural stem cells (red), originally reprogrammed from adult skin cells, functioning efficiently with  brain cells (green). Photo credit: Chen Lab, Penn State University via Pen State News

However when one of these cells gets damaged or dies, the result is damaged wiring and connections. If the damaged nerve is a motor neuron, then motor functioning is impaired. If the myelin cell is damaged, diseases such as Multiple Sclerosis (MS) develop.

Speaking at a TED Conference in July 2013, Dr. Siddharthan Chandran, director of the Centre for Clinical Brain Sciences, describes a case of a patient with MS whose brain scan showed myelin damage. Subsequent scans showed some repair in the area of the brain which had originally displayed damage. This repair had occurred with no medical intervention, which led Dr. Chandran to conclude that “the brain can repair itself, just not well enough.”

Dr. Chandran believes this discovery will lead to a new direction in finding therapies to treat brain disorders. Human stem cells, which can can self-renew to create new bone or liver cells, show great promise in this endeavour. Scientists hope that one day stem cells can be used to create new motor nerve or myelin cells.

In 2006, Japanese scientist Dr. Shinya Yamanaka discovered that just four ingredients can convert any adult cell into a master stem cell. This means that scientists can create a stem cell from any of us, and then make that cell relevant to our disease or injury, such as a motor neuron or a myelin cell. Yamanaka won a Nobel Prize for his work in 2012.

A recent clinical trial by Dr. Chandran, in collaboration with other scientists,  illustrates this point. Researchers took stem cells from the bone marrow of patients with MS, grew myelin cells in the lab, and then injected them back into the patients’ veins. To measure whether the intervention was successful, the scientists examined the optic nerve. The size of the optic nerve was measured before the injection of the lab grown myelin cells, three and six months post injection (patients with MS usually have vision problems). Results showed the optic nerve had stopped shrinking, which Dr. Chandran believes is the result of the injected myelin cells, which promoted the brain’s own stem cells to do their job of laying down more myelin.

In addition, scientists can now use human cells to find ways to promote and activate the stem cells, which are already in our brain, to repair damage. Dr. Chandran believes this technique could replace animal testing in the future.

Although Dr. Chandran discussed these new advances in the treatment of brain disorders such as MS and Parkinson’s, these scientific advances may have applicability to the brain injury as well. To quote Dr. Chandran, “the day we can repair the damaged brain is sooner than we think.”

Since her TBI in 2011, Sophia has educated herself about TBI. She is interested in making research into TBI accessible to other survivors.

via Can the brain repair itself? | Brain Injury Blog TORONTO.

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[WEB SITE] Stem cells can be safely infused in brain to promote stroke recovery, study finds

frontview661.jpgA yearlong study of stroke patients has found that stem cells from a patient’s bone marrow can be safely infused in the brain through the carotid artery to promote recovery. Researchers at the Interdisciplinary Stem Cell Institute at the University of Miami Miller School of Medicine followed 48 patients, more than half of whom who were treated using stem cells, and found recovery along with no adverse side effects when compared with their counterparts.

“The primary aim of this first U.S. trial of giving stem cells through the carotid artery was really safety: to establish safety beyond a good measure of doubt,” Dr. Dileep Yavagal, associate professor of neurology and neurosurgery at the University of Miami Miller School of Medicine and faculty member at the Interdisciplinary Stem Cell Institute, told FoxNews.com.

“The main concern that needed to be settled was that these cells by themselves could lead to decreased blood flow in the brain because they are live cells and they do occupy some space – a few microns each— and in laboratory studies, the concern had been raised that when you give them directly into the carotid artery, they can cause plugging,” Yavagal, also the director of interventional neurology and co-director of endovascular neurology said. “The study showed that that did not occur.”

In the trial, bone marrow from the patients was taken to an outside facility for about a 48-hour period in which the stem cells were separated and then shipped back to the procedure site to be infused. Of the 48 patients, 29 received the stem cells, while 19 received a placebo. The patients who received the cells were under conscious sedation as the cells were infused through a catheter in the groin area, up to the internal carotid artery in the brain. Each patient received the treatment within an average of 15 days after their stroke. Yavagal said each patient was given a relatively low dose to ensure the safety of the trial.

Continue —>  Stem cells can be safely infused in brain to promote stroke recovery, study finds | Fox News.

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[WEB SITE] The brain can rewire itself after an injury

Illustration by CRISTINA BYVIK

Living things can repair themselves. Damaged skin and fractured bones heal, and a damaged liver can regenerate itself.

Only recently have scientists begun to understand this is also true of the brain.

Perpetually responding to its environment, the brain possesses a remarkable ability to rewire itself, to actually reroute sensory impulses and change its physical structure.

Brain injuries, whether internally caused by a stroke or externally by some type of trauma, represent the supreme test of this regenerative ability.

Stroke is the third-leading cause of death in the United States, killing nearly 130,000 Americans annually, according to the U.S. Centers for Disease Control and Prevention. A total of 795,000 people have a stroke annually. Most of these strokes are ischemic — that is, caused by an interruption in oxygen supply to a part of the brain. Blood clots commonly cause ischemic strokes.

SPECIAL REPORT: THE WONDERS OF YOUR BRAIN

Meanwhile, brain trauma caused more than 50,000 deaths in the U.S. in 2010, according to the CDC. And traumatic brain injury was diagnosed in more than 280,000 hospitalization cases.

In children, falls caused 55 percent of such injuries. The rate soars to 81 percent in adults older than 65. Among all ages, motor vehicle crashes caused 14 percent of cases. And with the wars in Iraq and Afghanistan, thousands of American troops have endured such injuries.

Whether caused by stroke or external trauma, these brain injuries present much of the same challenges in rehabilitation, said Dr. Michael Lobatz, a neurologist with the La Jolla-based Scripps Health network. Undamaged parts of the brain need to learn how to take over functions normally performed by the portions that have been harmed.

Continue —>  The brain can rewire itself after an injury | UTSanDiego.com.

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