glia cells

“Eublepharis” By Rebecca McDonald, Vickaryous Lab, University of Guelph. Interstellate Volume 2 (in press).

This is an image of radial glia in the leopard gecko forebrain (GFAP, cyan). Radial glia are a type of neural stem cell that produce neurons, which then migrate down their lengthy processes. In mammals radial glia are present during development but not adulthood. In many non-mammalian species capable of brain regeneration, including lizards, radial glia are retained throughout life.

Inflamed Support Cells Appear to Contribute to Some Kinds of Autism

But researchers found that when glia cells were normal, they “rescued” autistic neurons in culture, causing the latter to behave normally

Modeling the interplay between neurons and astrocytes derived from children with Autism Spectrum Disorder (ASD), researchers at University of California San Diego School of Medicine, with colleagues in Brazil, say innate inflammation in the latter appears to contribute to neuronal dysfunction in at least some forms of the disease.  

The findings, published in the current issue of Biological Psychiatry, are the first to demonstrate that supporting brain cells, called astrocytes, may play a role in some subtypes of ASD. But more importantly, the research, using induced pluripotent stem cells, suggests the neuronal damage might be reversible through novel anti-inflammatory therapies. 

A confocal micrograph of a stained astrocyte grown in tissue culture. Blue indicates DNA, revealing the nucleus of the astrocyte and other cells. Image courtesy of EnCor Biotechnology.

To conduct the study, scientists took dental pulp cells from donated baby teeth of three children with diagnoses of non-syndromic autism (part of the on-going “Tooth Fairy Project”) and reprogrammed the cells to become either neurons or astrocytes, a type of glia or support cell abundantly found in the brain. The cells were grown into organoids, essentially mini-brains in a dish.

Though genetically distinct, all three children displayed stereotypical ASD behaviors, such as lack of verbal skills or social interaction. When researchers examined the developed organoids in microscopic detail, they noted that the neurons had fewer synapses (connections to other neurons) and other network defects. Additionally, some astrocytes showed high levels of interleukin 6 (IL-6), a pro-inflammatory protein. High levels of IL-6 are toxic to neurons.

The researchers co-cultured astrocytes derived from the ASD children with neurons derived from normal controls. The healthy neurons behaved like ASD neurons, said co-senior author Alysson R. Muotri, PhD, professor in the UC San Diego School of Medicine departments of Pediatrics and Cellular and Molecular Medicine, director of the UC San Diego Stem Cell Program and a member of the Sanford Consortium for Regenerative Medicine.

“But more importantly, the opposite was true. When we co-cultured ASD neurons with normal astrocytes, we could rescue the cellular defects. The neurons reverted to normal functioning and behavior.”

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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.”

Mouse hippocampus

WHAT IS IT?
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”).

WHY IS IT IMPORTANT?
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.

WHERE DO WE GO FROM HERE?
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.

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.)

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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!