Researchers design first model motor nerve system that's insulated and organized

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Researchers design first model motor nerve system that's insulated and organized

like the human body

Advances in lab-grown motor nerves can lead to cures for diabetic neuropathy and

help further understanding of multiple sclerosis and related conditions

http://www.eurekalert.org/pub_releases/2009-07/e-rdf072109.php

Amsterdam, 21 July 2009 - In the July issue of Biomaterials, published by

Elsevier, researchers from the University of Central Florida (UCF) report on the

first lab-grown motor nerves that are insulated and organized just like they are

in the human body. The model system will drastically improve understanding of

the causes of myelin-related conditions, such as diabetic neuropathy and later,

possibly multiple sclerosis (MS). In addition, the model system will enable the

discovery and testing of new drug therapies for these conditions.

MS, diabetic neuropathy, and many conditions that are caused by a loss of

myelin, which forms protective insulation around our nerves, can be debilitating

and even deadly. Adequate treatments do not yet exist. Researchers at the UCF

have identified this to be a result of a deficiency in model research systems.

Hickman, a bioengineer at UCF and the lead researcher on this project

explained: " The nodes of Ranvier act like power station relays along the myelin

sheath. They chemically boost signals, allowing them to get across breaks in

myelin, or from node to node, at the electrically charged nodes of Ranvier.

Nerve malfunctions, called neuropathies, involve a breakdown in the way the

brain sends and receives electric signals along nerve cells, leading to

malfunctions at the nodes of Ranvier, along with demyelination " . Hickman's team

has now achieved the first successful model nodes of Ranvier formation on motor

nerves in a defined serum-free culture system.

Researchers have long recognized the need for lab-grown motor nerve cells that

myelinate and form nodes of Ranvier in order to use controlled lab conditions to

zero in on the causes of demyelination. Yet, due to the complexity of the

nervous system, it has been a challenge to study demyelinating neuropathies, and

researchers have been confined to using animal models.

The main difference with this research was that Hickman's group began with a

model that was serum-free. They had already developed techniques for growing

various nervous system cells in serum-free media, including motoneurons, and

here they attempted myelination using the growth medium they have worked with

for many years.

In the body, nerve cells grow in two distinct environments: In the peripheral

nervous system (PNS), cells are exposed to blood and other fluids that contain

high concentrations of protein, among various other constituents, depending on

where the cells are located in the body. In the central nervous system (CNS),

the spinal cord and brain are surrounded by cerebrospinal fluid that contains

only trace amounts of protein. This system now allows for both the PNS and CNS

to be studied in the same defined system.

The UCF team plans to use their new model system to explore the origins of

diabetic neuropathy. Once the causes of myelin degradation are identified,

targets for new drug therapies can be tested with the model. Other planned

experiments will focus on how electrical signals travel through myelinated and

unmyelinated nerves to reveal how nerves malfunction as well as for spinal cord

injury studies. " Being able to study these fully developed structures means we

can really start looking at these things in a way that just wasn't possible

before, " commented Hickman.