glia cell


Dazzling Images of the Brain Created by Neuroscientist-Artist

 The brain has been called the most complex structure in the universe, but it may also be the most beautiful.

Greg Dunn earned a PhD in neuroscience before deciding to become a professional artist. His work captures both the aesthetics and sophistication of this most enigmatic organ. Here are a few of his dazzling creations:1-Cortical Columns, 2-Basket and Pyramidals, 3-Gold Cortex II, 4-Cortical Circuitboard, 5-Brainbow Hippocampus in Blues, 6-Brainbow Hippocampus variations, 7-Glia and Blood Vessels, 8-Glial Flare,  9-Spinal Cord

“There’s no distinction between painting a landscape of a forest and a landscape of the brain.”

The patterns of branching neurons he saw through the microscope reminded him of the aesthetic principles in Asian art, which he had always admired.

While much of Dunn’s work focuses on neurons, his subjects also include other tissue types, such as glia, non-neuronal brain cells that provide support and protection for neurons.(image 7-8)

One of Dunn’s most arresting pieces isn’t of the brain at all, but of a slice of the spinal cord.(image 9)

Through his art, Dunn hopes to give voice to scientists whose work usually isn’t appreciated by the general public, he said. “Art has the power to capture people’s emotions and inspire in a way that a lot of charts and graphs don’t have.”

How Do Biological Theorists Explain Abnormal Behavior?

Biological theorists view abnormal behavior as an illness brought about by malfunctioning parts of the organism. They typically point to problems in brain anatomy or brain chemistry as the cause of the problem.

- Brain Anatomy and Abnormal Behavior - 
The brain is made up of approximately 100 billion nerve cells, called neurons, and thousands of billions of support cells, called glia. Within the brain, large groups of neurons form distinct brain areas, one of which is known as the cerebrum. The cerebrum includes the cortex, corpus callosum, basal ganglia, hippocampus, and amygdala. Each of these brain regions control important functions:
• The cortex is the outer layer of the brain.
• The corpus callosum connects the brain’s two cerebral hemispheres.
• The basal ganglia plays a crucial role in planning and producing movement.
• The hippocampus helps regulate emotions and memory.
• The amygdala plays a key role in emotional memory. 
Researchers have found links between certain psychological disorders and problems in specific areas of the brain. One disorder is Huntington’s disease, which is a disorder marked by violent emotional outbursts, memory loss, suicidal thinking, involuntary body movements, and absurd beliefs. It has been traced to a loss of cells in the basal ganglia and cortex. 

- Brain Chemistry and Abnormal Behavior - 
Psychological disorders can also be related to problems in the transmission of messages from neuron to neuron. Information is communicated throughout the brain in the form of electrical impulses that travel from one neuron to one or more others. An impulse is received by a neuron’s dendrites, which then travels down the neuron’s axon, until it is finally transmitted through the nerve ending at the end of the axon to the dendrites of other neurons. 
Dendrites are antenna-like extensions located at one end of the neuron.
• The axon is a long fiber extending from the neuron’s body. 

Since the neuron’s don’t actually touch each other, you may wonder how the messages get from the nerve ending of one neuron to the dendrites of another. A tiny space called the synapse is what separates one neuron from the next. When an electrical impulse reaches a neuron’s ending, the nerve ending is stimulated to release a chemical known as a neurotransmitter, which travels across the synaptic space to receptors on the dendrites of the neighboring neurons. After binding to the receiving neuron’s receptors, the neurotransmitters can either have an excitatory or inhibitory response. Some neurotransmitters give a message to the neurons to “fire” or trigger their own electrical impulse, while others tell receiving neurons to stop all firing. 

Studies have shown that abnormal activity by some neurotransmitters can lead to certain mental disorders. For example, depression is linked to low activity of the neurotransmitters serotonin and norepinephrine.

Abnormal chemical activity in the endocrine system has also been shown to be related to mental disorders. Endocrine glands, located throughout the body, work with neurons to control vital activities such as growth, reproduction, sexual activity, heart rate, body temperature, energy, and stress response. The glands release chemicals known as hormones into the bloodstream that propel body organs into action. During times of stress, for example, the adrenal glands, located on top of the kidneys, secrete the hormone cortisol to help the body deal with the stress. Abnormal secretion of this chemical has been linked to anxiety and mood disorders. 

(Comer, R. J. (2004). Abnormal psychology (8th ed.). New York: Worth.)

Mouse hippocampus

The hippocampus is found deep in the brains of many mammals, including humans. It’s named for its seahorse shape (in Greek, hippokampos literally means “horse sea monster”).

It helps us form memories and navigate space. It contains special cells called “place cells” that create a mental map of our environment. The hippocampus is also one of the first structures to suffer in patients with Alzheimer’s disease, which is characterized by memory loss. The number of patients with Alzheimer’s is predicted to triple by 2050.

Scientists at Harvard Medical School were recently able to re-create Alzheimer’s disease from human cells in a culture dish. This will “revolutionize drug discovery in terms of speed, costs and [disease relevance],” according to a senior co-author on the study.

Image by Chris Henstridge/MTA-KOKI/Nikon Small World.


Hey, scientists! Can we do Brain mapping? 

Hello my favorite people! This is my group’s AP bio final project, which is a thrift shop parody, and we’d love it if you give it a watch. You won’t be disappointed! I promise! Also please give it a thumbs up and a comment if you’re logged into your google account! Thanks!

deercr0ssing  asked:

I hope speculation is encouraged. I'm slightly scientifically literate, but I lack any meaningful qualifications. I'm obsessed with the concept of consciousness. I have two hypothesizes that I'm wondering if you could provide any insight to prove/disprove their possibility. First: I tend to think of neurons as finite fragments of information, but storage nonetheless. But the actual conscious takes place between the synapses. Second: Conscious, on some scale, must have quantum properties.. right?

Speculation is always encouraged! It is nice to hear someone else is also obsessed with consciousness. I want to warn you now that I am passionate about this topic, and so will probably answer in a long winded manor.

First, the problem of information is one of the most fundamental problems the world of neuroscience must answer. That is, what is the basic information unit that is being transferred? It does seem to have something to do with neurons, but exactly what is being transferred? Information could be contained in the electrochemical signals (typically action potentials) between neurons. However the probability of an action potential occurring is regulated by a large range of factors, such as membrane permeability, neurotransmitter concentration, receptor concentration, etc. One level lower, the information could be contained in the diffusion of water across neurons and glia cells. Even lower, it could be the transfer of electrons through various biological constraints. The same can be said about storage. The concurrent firing of action potentials leads to changes in the synapses, myelin, cell walls, and can even lead to additional synapses (or neurons). Exactly what is being stored is where is not entirely clear.

Ultimately I think all of the above (and much more) can be thought of as information. Likewise, consciousness probably involves the transfer of information in many other ways, not just the synapses. As a science, we are slowly moving away from the idea that there must be ‘finite fragments of information’, which most likely stemmed from our experience with computers where there is fundamental discrete information - a bit. (Personal note: this is the main reason why I am currently focused on investigating the process of consciousness, instead of the mechanism.) 

Second, I am not sure what you mean by quantum properties. Ultimately, everything is based off of quantum properties, but I see no reason that consciousness requires specific quantum relationships. I often hear that entanglement may be the solution to consciousness, where atoms or molecules can transfer information instantaneously. As far as I know, there is no reason at all to require entanglement in consciousness, though the media loves it. In my opinion, talking about quantum properties for consciousness is interesting, but does not tell us anything new about consciousness and merely adds convolution. Right now, we need to focus on what we know, and what we can test. 

For example, we now know that access consciousness (if you don’t know what that is, look up Ned Block) requires a feedback loop. In vision, light enters the retina, is sent first to the visual cortex, then the frontal cortices, and then back to the visual cortex (disclaimer: this is way oversimplified). If we use TMS to knock out the feedforward stream from the visual cortex to the frontal cortex, we still consciously perceive the stimulus. However, if we knock out the feedback stream from the frontal cortices to the visual cortex, we lose conscious awareness. These sort of experiments lead to a deeper understanding, and until we tease apart everything we can about the process of consciousness, I don’t think we can say anything about how it occurs.

I hope this answered your questions. If not, or if something is not clear, please let me know! The more collaboration we have on the topic, the more likely we will come to a solution. 

Cells from eyes of dead ‘may give sight to blind’

Cells taken from the donated eyes of dead people may be able to give sight to the blind, researchers suggest.

Tests in rats, reported in Stem Cells Translational Medicine, showed the human cells could restore some vision to completely blind rats.

The team at University College London said similar results in humans would improve quality of life, but would not give enough vision to read.

Human trials should begin within three years.

Donated corneas are already used to improve some people’s sight, but the team at the Institute for Ophthalmology, at UCL, extracted a special kind of cell from the back of the eye.

These Muller glia cells are a type of adult stem cell capable of transforming into the specialised cells in the back of the eye and may be useful for treating a wide range of sight disorders.

[read more]

Study Identifies Unexpected Clue to Peripheral Neuropathies

New research shows that disrupting the molecular function of a tumor suppressor causes improper formation of a protective insulating sheath on peripheral nerves – leading to neuropathy and muscle wasting in mice similar to that in human diabetes and neurodegeneration.

Scientists from Cincinnati Children’s Hospital Medical Center report their findings online Sept. 26 in Nature Communications. The study suggests that normal molecular function of the tumor suppressor gene Lkb1 is essential to an important metabolic transition in cells as peripheral nerves (called axons) are coated with the protective myelin sheath by Schwann glia cells.

“This study is just the tip of the iceberg and a fundamental discovery because of the unexpected finding that a well-known tumor suppressor gene has a novel and important role in myelinating glial cells,” said Biplab Dasgupta PhD, principal investigator and a researcher at the Cincinnati Children’s Cancer and Blood Diseases Institute (CBDI).  “Additional study is needed, as the function of Lkb1 may have broader implications – not only in normal development, but also in metabolic reprogramming in human pathologies. This includes functional regeneration of axons after injury and demyelinating neuropathies.”

The process of myelin sheath formation (called myelination) requires extraordinarily high levels of lipid (fat) synthesis because most of myelin is composed of lipids, according to Dasgupta. Lipids are made from citric acid which is produced in the powerhouse of cells called mitochondria. Success of this sheathing process depends on the cells shifting from a glycolytic to mitochondrial oxidative metabolism that generates citric acid, the authors report.

Dasgupta’s research team used Lkb1 mutant mice in the current study. Because the mice did not express Lkb1 in myelin forming glial cells, this allowed scientists to analyze its role in glial cell metabolism and formation of the myelin sheath coating.

When the function of Lkb1 was disrupted in laboratory mice, it blocked the metabolic shift from glycolytic to mitochondrial metabolism, resulting in a thinner myelin sheath (hypomyelination) of the nerves. This caused muscle atrophy, hind limb dysfunction, peripheral neuropathy and even premature death of these mice, according to the authors.

Peripheral neuropathy involves damage to the peripheral nervous system – which transmits information from the brain and spinal cord (the central nervous system) to other parts of the body, according to the National Institute of Neurological Disorders and Stroke (NINDS). There are more than 100 types of peripheral neuropathy, and damage to the peripheral nervous system interferes with crucial messages from the brain to the rest of the body.

The scientists also reported that reducing Lkb1 in Schwann cells decreased the activity of critical metabolic enzyme citrate synthase that makes citric acid. Enhancing Lkb1 increased this activity.

They tested the effect of boosting citric acid levels in the Lbk1 mutant Schwann cells. This enhanced lipid production and partially reversed myelin sheath formation defects in Lbk1 mutant Schwann cells. Dasgupta said this further underscores the importance of Lbk1 and the production of citrate synthase.

Dasgupta and his colleagues are currently testing whether increasing the fat content in the Lbk1 mutant mice diet improves hypomyelination defects. The researchers emphasized the importance of additional research into the laboratory findings to extend their relevance more directly to human disease.