Stem Cell Recreates 3D Neural Structure of Brain's Cerebellum

Scientist have successfully coaxed undifferentiated stem cells to form functioning cerebellar neurons that mimiced the dorsal/ventral patterning and multi-layer structure found in the cerebellum.

The experiment conducted at the RIKEN Center for Developmental Biology in Japan applied signaling molecules to 3D cultures of human embryonic stem cells which prompted the cells to form into cerebellar neurons. These neurons self-organized to form the proper dorsal/ventral patterning and multi-layer structure found in the natural developing cerebellum. The image above are that of mature Purkinje cells (a type of neuron) that was grown from Human Embryonic Stem Cells.

The researchers noted that the experiment may lead to technologies and other discoveries that will be useful for modeling cerebellar diseases such as spinocerebellar ataxia; a progressive, neurodegenerative,genetic disease that has no known treatment or cure.

Neurons are cells of the nervous system that transmits information and signals to and from the brain. They the main component of the nervous system which also includes the brain, spinal cord, and peripheral ganglia (relay points and intermediary connections between different neurological structures in the body). Neurons are not made or replaced after birth. Scientists are looking at stem cell technology to address medical conditions and disorders that are affected by neurons since stem cells can differentiate into neurons.

Stem cells, specifically human embryonic stem cells, are cells that can change itself into a higher form of cell, tissue, or organ.

Their findings are published in Cell Reports.

New Process Developed To Image How The Brain Forms Memories

Researchers at Albert Einstein College of Medicine of Yeshiva University have imaged the brain while forming memories on the molecular level. This was achieved by tagging fluorescent beta-actin mRNA molecules using a mouse model.

The tagged molecules were observed by the scientists in real time while brain cells were forming memories. See embedded video.

They note that the stimulated individual hippocampal neurons caused a rapid transcription of the beta-actin gene within 10 to 15 minutes. The hippocampus is the region of the brain where where memories are made and stored. These beta-actin mRNA molecules continuously assemble and disassemble into large and small particles, respectively. These mRNA particles were seen traveling to their destinations in dendrites where beta-actin protein would be synthesized.

The neurons connect to each other through spines of dendrites where long-lasting synaptic connections form between neurons in contact with each other. The Beta-actin protein appears to strengthen these synaptic connections by altering the shape of dendritic spines.

Ankyrin-G and Kinesin-1 Protein Responsible For Movement Mechanics of Neuron's Sodium Ion Channel to Axon

Nerve Impulse

Scientists have discovered how sodium ion channels travel from the neuron to the axon to initiate central nervous communications to and from the brain. They observed that two proteins, Ankyrin-G and Kinesin-1, play an important role in the process. The ankyrin-G protein tethers the sodium ion channel to the axon while kinesin-1 transports it to the axon.

This process is fundamental in moving nerve signals along the central nervous system. These nerve signals, carried by the sodium ion channel, cover information like sense (touch, feel, taste, etc), movement, memory, and thinking. These signals, which are electrical and chemical in nature, do not fire up all at once, it jumps from axon to axon.

The image of a neuron above shows how the nerve impulse travels along the axon which is the long, slender extension of the nerve cell body.

Scientists have long wondered how the mechanics of the movement of the sodium ion channels, the protein responsible for the signals, from the neuron to axon works. These proteins have to be delivered to the axon or else nothing happens.

There are about 80 to 100 billion neurons in the human brain. These are interconnected to each other through synapses in which there are about 100 trillion. The neural network transmits information through electrical and chemical signals.

Research Traces Link Between Beta Amyloid Protein, PirB/LilrB2 Protein And Alzheimer's Disease

PirB (red) is heavily concentrated on the surface of growing nerve cells.
Credit: Dr. Carla Shatz, Stanford University.

Stanford University School of Medicine researchers suggest that a link between the beta-amyloid protein and the PirB/LilrB2 protein may be a strong factor in the development of Alzheimer's Disease. The LilrB2 protein found in humans and its counterpart, the PiirB protein found in mice controls the visual system development in the brain. Research show that these class of proteins bind with the beta-amyloid protein which triggers the onset of Alzheimer's disease.

The research also shows that depleting PirB in the brain of the mouse model prevented the chain reaction and reduced memory loss. This discovery can lead to the development of treatments that can delay, treat or even prevent this this disease.

Alzheimer's disease causes brain cells to die and damages brain affecting its functions such as cognition, memory, and the control of the body's processes. Protein fragments, called plaques and tangles, stick together to form the Alzheimer's protein which stats to kill brain cells. The disease starts at the Hippocampus and ultimately destroys the whole brain.

The slow progression of the disease takes around eight to ten years from beginning to end which starts with memory loss. It then starts to spread and affect the part of the brain that controls balance and mobility. Ultimately, the disease starts attacking the area where breathing and heart functions are controlled.

Alzheimer's disease is a form of dementia that affects more than 5 million Americans. Currently there is no cure for the disease.

Developing More Efficient Hearing Aids Through OCH Transduction

Researchers are studying how the cochlea, located in the ear, processes and amplifies sound. This research could lead to better hearing aids.

Scientists have discovered that hearing relies on a mechanical traveling wave that is actively boosted by electromechanical forces in sensory outer hair cells (OHCs). By studying the process of OHC transduction, better devices that can send more accurate sound signals to brain can be developed.

Transduction is the conversion of a sensory stimulus (hearing, sight, taste, etc) to a sensory signal that the brain can process.

Just recently, scientists have also discovered a protein called TMHS that may be a critical component in converting soundwaves to electrical signals that the brain can process.

Genetically Engineered Protein, ArcLight, Allows Direct Observation of Brain's Electrical Activity

Scientists have genetically engineered a new protein called ArcLight to observe electrical activity in the neurons of the brain.

The brain receives and transmits information by using electrical signals. These signals travel through synapses and neurons. By tracking neural activity in the body in real time, scientists get to understand how the brain works.

There are different ways to monitor and observe brain activity such as MRI and fMRI which monitors the blood, water, and oxygen flow in the brain through magnets and radio waves.

Another way is to use chemical calcium detectors that are fluorescent in nature. As signals travel through the neural network, the cells undergoes a shift in the concentration of its internal calcium ions. When this change in calcium ions is detected by the chemical, it reacts to it by glowing.

With the development of ArcLight, scientists may be able to directly observe neural electrical activity in real time and even in parts of the brain that were previously inaccessible using other techniques.

Imaging Neurons While New Memories Are Formed Using mRNA Display and Microscopic FingRs Probes

Scientists have, for the first time, imaged neurons while new memories are being formed. This was done by using fluorescent markers on the synaptic proteins connected to the neurons. The scientists also developed microscopic probes called FingRs as well as a tracking technique, mRNA Display, to find and visualize the neurons during the memory formation process.

Neurons are the cells responsible for transmitting information to and from the brain. It is the core component of the nervous system. Each of these neurons are interconnected through synapses. Synapses are structures similar in function to telephone cables, that allow the passing of electrical or chemical signals between the neurons.

The image on the left (courtesy of Don Arnold), shows a living neuron in culture. The green dots indicate the excitatory synapses and the red dots indicate inhibitory synapses. An excitatory synapse is a synapse that increases the chance of an action potential occurring in a postsynaptic cell. An inhibitory synapse is the opposite, it decreases the chance of an action potential.

Neurons need a lot of the body's resources to perform efficiently. The metabolic requirements for these require about 15% of the output of the heart (cardiac output), 20% of the body's oxygen consumption, and 25% of the body's glucose utilization. The brain only takes energy from glucose.

There are about 80 to 100 billion neurons in the human brain. And there are about 100 trillion synapses connecting the neurons together. Looking at a portion of the brain, the size of a pinhead, one would find around 30,000 neurons in it.

The most number of neurons a person could ever have is during the first trimester as a fetus. Neurons are not made or replaced during one's life. Current developments in medicine have shown that neurons can be made and repaired using stem cell technology.

Scientists Study How Brain Stores Long Term Memory in the Brain

RIKEN Brain Science Institute researchers have successfully for the first time imaged how long term memories are stored as information in the cerebral cortex using zebrafish and calcium imaging.

Calcium imaging is an imaging method where protein based indicators are monitored when they react to chemical changes in the brain. These indicators are given a fluorescent dye for easy monitoring as the indicators glow when the reaction happens.

Neurons transmit information to the brain through electrical signals. As these signals travel through the neural network, each cell within the path undergoes a shift in its internal calcium ion (Ca2+) concentration. This happens because specialized channels allow ions to flood into the cytoplasm. This shift in calcium ion concentration is a good indicator for tracking neural activity in real time.

By developing fluorescent protein-based Ca2+ indicators, scientists can track neural activity of cells being observed.

Since the human brain is big and complex with millions of neurons, scientists at Riken have used a zebrafish to monitor these neuron reactions. This development comes closely to their groundbreaking discovery of visualizing brain activity in a zebrafish. In an earlier unrelated study by MIT, their research notes that using zebrafish to study how the brain works is a useful tool (see related links).

V5 Region of Visual Cortex Responsible For Tracking Fast Moving Object

In a study conducted by UC Berkeley scientists, research shows that for the brain to process fast moving objects, the V5 region of the visual cortex accurately predicts where and how these objects move.

The part of the brain responsible for processing visual information is the Visual Cortex. It can be found in the back of the brain in the Occipital Lobe. Each hemishphere of the brain has its own visual cortex with the right one processing signals from the left visual field and the left one processing signals from the right visual field.

The visual cortex can be grouped into 5 regions; V1, V2, V3, V4, and V5. Each region is responsible for a specific role in visual processing such as spatial recognition and information (V1), long term and short term visual memory (V2), processing of motion- coherent and global (V3) color and shape recognition (V4) and tracking of moving objects (V5).

Finding out specific roles of each region is still an ongoing process and the recent UC Berkeley study show that the V5 region is important in tracking fast moving objects where the speed of the object may be faster than how the brain processes the information.

The V5 region of the visual cortex is also known as the Middle Temporal (MT). This region is believed to be responsible for the processing of motion and moving objects.

Stem Cells Transformed Into Brain Neurons For the First Time

Stem cell research and development have grown tremendously over the past few years. Stem cell technology have opened up novel therapies against complicated neurological diseases such as Alzheimer's Disease and Parkinson's Disease. Scientists at the University of Wisconsin-Madison have, for the first time, used human embryonic stem cells to create new neurons in the brain that can help it regain memory and cognitive functions.

Stem cells are special type of cells that can transform itself into a higher form of cell, tissue, or organ. Each biological system or organ has its own specialized stem cell that can transform into a tissue within that system (a heart stem cell can differentiate into a heart tissue). But human embryonic stem cells are a higher form of stem cells in that it can differentiate into any other type of cell; a characteristic called pluripotency.

This pluripotency is what drives stem cell research as it can be used to treat conditions such as Alzheimer's where brain cells are slowly being destroyed. Neurons behave different from other types of cells in that they cannot replicate or grow back if damaged. Using stem cells to differentiate into neurons mean that the brain can be treated and possibly healed.

Cellular Reprogramming In Treatment of Multiple Sclerosis, Cerebral Palsy and other Myelin Disorders.

Researchers have successfully converted fibroblasts (a structural cell) into oligodendrocytes which could regenerate new myelin coatings around nerves. This treatment can be used in myelin related disorders such as multiple sclerosis and cerebral palsy.

Cellular Reprogramming is a technique that allows the conversion of one type of cell into another. Although it shares a similar concept with stem cell technolgy, unlike stem cell therapy, cellular reprogramming utilizes direct manipulation of the cell at a genetic level to convert it into another type of cell.

Stem cells naturally differentiate into another type of cell. In 2012, Doctor Shinya Yamanaka won the Nobel Prize in Physiology or Medicine for his research on generating induced pluripotent stem cells (iPS cells) through cellular reprogramming. iPS cells are pluripotent stem cells that are artificially derived from normal cells.

New Neurostimulation Techniques in Spinal Cord Stimulators For Pain Management Developed

Researchers have developed new techniques in implanted spinal cord stimulators to reduce common complications at the implant site. Spinal cord stimulators are devices used in neurostimulation to manage chronic pain conditions.

Neurostimulation is a type of treatment and therapy where neurons in the nervous system are stimulated to either restore functionality of a certain organ, control an organ, or induce/reduce a specific nerve signal within the system. This is done through micro-electrodes that deliver electrical signals to the neurons.

There are four types of neurostimulation. These are brain stimulation, deep brain stimulation, transcranial magnetic stimulation (TMS), and spinal cord stimulation (SCS).

Of the four, spinal cord stimulation is used for the treatment and therapy of chronic pain. It includes conditions such as migraine, paralysis, diabetic neuropathy, Failed Back Surgery Syndrome, complex regional pain syndrome, and other conditions where pain management cannot be effectively be treated through medication or where SCS can augment medication to deliver a better quality of life.

SCS uses electrical stimulation to ease the sensation of pain by suppressing the feeling of pain. Implanted micro-electrodes sends out electrical impulses , through an electrical pulse generator, to the tissue. The pulses are regulated and controlled by a device that adjusts the frequency and strength of the signal.

Spinal cord stimulation is the most popular type of neeurostimulation to manage chronic pain syndromes.

Spinal Cord Tracts and Pathways
Credit: Wikipedia

The Effect of Serotonin on the Brain and In Central Fatigue

A study has been released concerning the effect of serotonin on the body in relation to exhaustion and central fatigue.

There are about 100 billion nerve cells called neurons in the human brain. These neurons all consist of a cell body with dendrites and a nerve fiber called the axon. These neurons communicate with each other through a network of connecting synapses. Nerve impulses send signals through the axon from the cell body to the nerve endings.

One kind of neuron is the motor neuron or motoneuron. Motoneurons are the cells that connect the muscles to the central nervous system. Signals from the brain reach these muscles through the motor neurons which leads to the muscle to move or contract. Precise signals from the brain through the neurons allow the muscle to move and coordinate with the task at hand. It is in this process that serotonin plays a role as a neurotransmitter to coordinate the movement. Neurotransmitters are the chemicals which allow the transmission of signals from one neuron to the next across synapses.

Serotonin and Its Role in Central Fatigue

Serotonin is a biochemical that is used in many of the bodies function. It is involved in processes that affect sleep, appetite, sex, and muscle control. As soon as the body starts moving, serotonin is released. It functions as an accelerator for movement and makes motor neurons more active.

According to the study, when large amounts of serotonin are released, it causes an overflow in the synapse where neurons communicate. This results in serotonin to bind with other receptors outside of the intended synapses. Some of these receptors are located where nerve signals are formed and when activated, the impulse is blocked. This results in weakened muscular contraction and fatigue sets in.

Brain Process In Encoding Sound Key In Study of Dyslexia

Northwestern University researchers found a systematic relationship between reading and how the brain encodes sound that may be key in understanding dyslexia.

Dyslexia is a disability where a person has difficulty processing letters and symbols. Also known as Developmental Reading Disorder (DRD), Dyslexia occurs when the part of the brain that helps process language does not recognize certain symbols or letters that is read by the person.

Dyslexia is not an eye or vision problem, it is an information processing problem. Normal thinking and cognitive functions are not affected and most people with dyslexia have normal intelligence, and many have above-average intelligence.

Disorders related to DRD are Developmental Writing Disorder (Orthographic Dyslexia) and Developmental Arithmetic Disorder (Dyscalculia). These conditions may appear alone or in any combination. All three involves the processing and interpretation of symbols and all three are considered a type of dyslexia. DRD is the most common and most associated with dyslexia.

There are four types of dyslexia:

• Phonological Dyslexia - Difficulty separating component parts of a sentence.
• Orthographic Dyslexia - Problem with writing such as spelling patterns
• Dyscalculia - Problem with basic sense of number and quantity
• Dysgraphia - Disorder which expresses itself primarily through writing or typing.

Update On Spinal Cord Injury Treatment Through Robotics, Neurorehabilitation, and Electrical-Chemical Stimulation

An update on the research conducted last year on repairing spinal cord injury is set to be delivered at the 2013 Annual Meeting of the American Association for the Advancement of Science (AAAS) in Boston.

In the June 01 issue of Science, Grégoire Courtine, of the École Polytechnique Fédérale de Lausanne (EPFL) published a report on how rats with spinal cord injuries and severe paralysis managed to walk and even run again.

"After a couple of weeks of neurorehabilitation with a combination of a robotic harness and electrical-chemical stimulation, our rats are not only voluntarily initiating a walking gait, but they are soon sprinting, climbing up stairs and avoiding obstacles," explains Courtine, who holds the International Paraplegic Foundation (IRP) Chair in Spinal Cord Repair at EPF

Courtine used a cemical solution that triggers cell responses to specific receptors on the spinal neurons. This chemical, monoamine agonists, replaces neurotransmitters and acts to excite neurons. After the injection, the spinal cord is electrically stimulated with electrodes. The electrical stimulation sends continuous electrical signals through nerve fibers to the chemically excited neurons that control leg movement.

Every year, around 50,000 people suffer spinal cord injuries, most result in paralysis. This study may lead to effective treatments of these injuries and allow patients to walk again and even fully recover from it.

Darkness Therapy In Treatment of Visual Brain Disorders Like Amblyopia

Depriving normal visual experience in one eye early in life produces a reduction in visual acuity (amblyopia) for that eye (blue circles) while the acuity of the other eye is normal (red). The visual acuity of the amblyopic eye remains low compared to the fellow eye, but after immersion in complete darkness the amblyopic eye very quickly recovers to match the visual acuity attained by the normal eye.
Credit: Current Biology, Duffy et al.

Researchers at Dalhousie University in Canada are using total immersion in darkness in the treatment and therapy for visual brain disorders such as amblyopia.

Amblyopia, also known as 'lazy eye', is a condition when one eye does not develop a proper nerve pathway to the brain. The other eye is unaffected by this and sends stronger neuro-electrical signals than the weaker one. This confuses the brain and eventually it ignores the signals coming from the weaker eye. This results in damaged and impaired vision.

Usual treatment for Amblyopia is to cover the stronger eye with an eye patch to force the weaker eye to strengthen and stimulate impulses for that eye. This allows the person to restore normal vision.

Treating Amblyopia during early childhood, especially before the age of 5, increases the chance of successfully treating it. The earlier it is detected, and the underlying cause corrected with spectacles and/or surgery, the more successful the treatment in equalizing vision between the two eyes.

Kevin Duffy and Donald Mitchell of Dalhousie University believe that darkness therapy, where the patient is immersed in total darkness is another way of treating amblyopia and other visual brain disorders without the use of surgery, drugs, and other procedures.

Stem Cell May Repair Damage or Loss of Neurons in The Enteric Nervous System

The Enteric Nervous System is a collection of nerve cells (neurons) in the gut from the esophagus to the rectum. It is known as the brain of the gut. It is autonomous to the central nervous system and functions independently from it.

Proper function of the digestive system requires coordinated contraction of the muscle in the wall of the intestinal tract, regulated by the enteric nervous system. Damage or loss of these neurons can result in intestinal motility disorders, such as Hirschsprung's disease, for which there is a dearth of effective treatments.

Visualizing Zebrafish Brain Activity - How Fish Think

For the first time, researchers have been able to see a thought "swim" through the brain of a living fish. The new technology is a useful tool for studies of perception. It might even find use in psychiatric drug discovery, according to authors of the study, appearing online on Jan. 31 in Current Biology, a Cell Press publication.
Credit: Current Biology, Muto et al.

Researchers have successfully visualized brain activity in a zebrafish. This discovery may aid in screening and discovering chemicals that affect neuronal activity in the brain.

Imaging brain activity in humans have been made possible through technologies such as MRI and fMRI. These imaging systems use powerful magnets and radio waves to detect blood, water and oxygen flow within the brain. But in more simple organisms such as the zebrafish, MRI imaging of normal neuronal activity is impossible.

Another method is by using protein based indicators that react to certain chemical changes within the brain. These indicators are fluorescent in nature for scientists to monitor when the chemical changes happen (they glow when the reaction is present).

Neurons transmit information to the brain through electrical signals. As these signals travel through the neural network, each cell within the path undergoes a shift in its internal calcium ion (Ca2+) concentration. This happens because specialized channels allow ions to flood into the cytoplasm. This shift in calcium ion concentration is a good indicator for tracking neural activity in real time.

By developing fluorescent protein-based Ca2+ indicators, scientists can track neural activity of cells being observed.

New Observation on the Role of Rhodopsin and Retinal Degenerative Diseases

New observation on the behavior between rhodopsin and photoreceptor cells could help explain retinal degenerative diseases and find new ways to treat blindness.

Retinal degenerative diseases refers to diseases that causes the retina, the light-sensitive layer of tissue, lining the inner surface of the eye, to deteriorate. As it deteriorates, cells of the retina starts to die.

Of the cells affected by retinal degeneration, the photoreceptor cells are most important. Photoreceptor cells are neurons that convert light stimuli into signals for the brain to process.

Neurons are unlike some other cells as they do not divide or multiply. Damaged or dead photoreceptor cells can cause vision impairment and even blindness.

How photoreceptor cells die is still under study. It is believed that the biological pigment in photoreceptor cells of the retina called rhodopsin may have something to do with it. Rhodopsin is extremely sensitive to light, enabling vision in low-light conditions, and is responsible for triggering the eye to see light.

Neurobiologists Transform Projection Neuron To Motor Neuron Inside Brain Through Direct Lineage Reprogramming

Neurobiologists have converted a brain neuron from one type to another. By successfully transforming a projection neuron to a motor neuron, their research can open up positive developments in the treatment and cure for neurological diseases such as ALS.

Neurons are cells that transmits information to and from the brain. They are the main component of the nervous system which includes the brain, spinal cord, and peripheral ganglia (relay points and intermediary connections between different neurological structures in the body).

There are about 80 to 100 billion neurons in the human brain. These are interconnected to each other through synapses in which there are about 100 trillion. The neural network transmits information through electrical and chemical signals.

No new neurons are made during one's life. Because of that, the brain has the most number of neurons during the last trimester as a fetus. From there, the number of neurons in the brain stay the same all throughout one's life.

Neurons need a lot of the body's resources to perform efficiently. The metabolic requirements for these require about 15% of the output of the heart (cardiac output), 20% of the body's oxygen consumption, and 25% of the body's glucose utilization. The brain only takes energy from glucose.

There are different types of neurons, each with a specialized function. Sensory neurons are responsible for sound, touch, sight, and other stimuli corresponding to the sensory organs. Motor neurons use signals from the brain and spinal cord to move and contract muscles and organs. There are also interneurons that connect neurons to other nearby neurons within the network. Another type of interneuron is the projection neuron that connects to far more distant neurons within the neural network.

Neurons do not undergo cell division. Most neurons are generated by special types of stem cells. Astrocytes, a type of glial cell, have also been observed to turn into neurons by virtue of the stem cell characteristic pluripotency.