Tag Archives: axons

Effects of estrogen treatment combat multiple sclerosis in mice

A study by UCLA researchers reveals the cellular basis for how the hormone estrogen protects against damage to the central nervous system in women with multiple sclerosis, or MS. The researchers found that estrogen treatment exerts positive effects on two types of cells during disease — immune cells in the brain as well as cells called oligodendrocytes. (more…)

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Mystery Solved: How Nerve Impulse Generators Get Where They Need to Go

Study identifies essential molecule for transport of protein from neuron cell body to axon

COLUMBUS, Ohio – Scientists have solved a longstanding mystery of the central nervous system, showing how a key protein gets to the right spot to launch electrical impulses that enable communication of nerve signals to and from the brain.
 
Nerve impulses are critical because they are required for neurons to send information about senses, movement, thinking and feeling to other cell types in the neural circuitry. And an impulse is not fired up just once; it is initiated and then must be repeatedly transmitted along axons – long, slender extensions of nerve cell bodies – to keep the nervous system’s messages stable during their rapid travel. (more…)

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Multiple Sclerosis Study Reveals How Killer T Cells Learn to Recognize Nerve Fiber Insulators

Misguided killer T cells may be the missing link in sustained tissue damage in the brains and spines of people with multiple sclerosis, findings from the University of Washington reveal. Cytoxic T cells, also known as CD8+ T cells, are white blood cells that normally are in the body’s arsenal to fight disease.

Multiple sclerosis is characterized by inflamed lesions that damage the insulation surrounding nerve fibers and destroy the axons, electrical impulse conductors that look like long, branching projections. Affected nerves fail to transmit signals effectively. (more…)

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First Measurements Made of Key Brain Links

Until now, brain scientists have been almost completely in the dark about how most of the nonspecific thalamus interacts with the prefrontal cortex, a relationship believed to be key in such fundamental functions as maintaining consciousness and mental arousal. Brown University researchers performed a set of experiments, described in the Journal of Neuroscience, to explore and measure those circuits for the first time.

PROVIDENCE, R.I. [Brown University] — Inside the brains of mice and men alike, a relatively big football-shaped region called the thalamus acts like a switchboard, providing the prefrontal cortex, the part that does abstract thinking and decision-making, with most of its information. The thalamus’s responsibility even includes helping the prefrontal cortex to maintain consciousness and arousal. (more…)

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A Whole New Meaning for Thinking on Your Feet

Smithsonian researchers report that the brains of tiny spiders are so large that they fill their body cavities and overflow into their legs. As part of ongoing research to understand how miniaturization affects brain size and behavior, researchers measured the central nervous systems of nine species of spiders, from rainforest giants to spiders smaller than the head of a pin. As the spiders get smaller, their brains get proportionally bigger, filling up more and more of their body cavities.

“The smaller the animal, the more it has to invest in its brain, which means even very tiny spiders are able to weave a web and perform other fairly complex behaviors,” said William Wcislo, staff scientist at the Smithsonian Tropical Research Institute in Panama. “We discovered that the central nervous systems of the smallest spiders fill up almost 80 percent of their total body cavity, including about 25 percent of their legs.” (more…)

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UCLA Researchers Identify Molecular Program for Brain Repair Following Stroke

Mouse Stroke. An MRI of a mouse brain after stroke. The mouse section has been stained to show cell bodies. Image credit: University of California

A stroke wreaks havoc in the brain, destroying its cells and the connections between them. Depending on its severity and location, a stroke can impact someone’s life forever, affecting motor activity, speech, memories, and more. 

The brain makes an attempt to rally by itself, sprouting a few new connections, called axons, that reconnect some areas of the brain. But the process is weak, and the older the brain, the poorer the repair. Still, understanding the cascade of molecular events that drive even this weak attempt could lead to developing drugs to boost and accelerate this healing process. 

Now researchers at UCLA have achieved a promising first step. Reporting in the current online edition of the journal Nature Neuroscience, senior author Dr. S. Thomas Carmichael, a UCLA associate professor of neurology, and colleagues have, for the first time, identified in the mouse the molecular cascade that drives the process of reconnection or sprouting in the adult brain after stroke.  (more…)

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