Navigation Links
Growth factor stimulates rapid extension of key motor neurons in brain

A growth factor known to be important for the survival of many types of cells stimulates rapid extension of corticospinal motor neurons ?critical brain cells that connect the cerebral cortex with the spinal cord and that die in motor neuron diseases like amyotrophic lateral sclerosis (ALS or Lou Gehrig's disease). In the November 2006 issue of Nature Neuroscience, two investigators from Massachusetts General Hospital (MGH) and the Harvard Stem Cell Institute describe how insulin-like growth factor 1 (IGF-1) dramatically increases the in vitro growth of corticospinal motor neuron (CSMN) axons ?projections that carry nerve impulses to the spinal motor neurons that connect to muscles ?and that blocking IGF-1 activity reduces that growth in both cultured cells and in living mice.

"Our findings that IGF-1 specifically enhances both the speed and extent of axon outgrowth of corticospinal motor neurons are the first direct evidence of growth factor control over the differentiation of these neurons, " says Jeffrey Macklis MD, DHST, director of the MGH-Harvard Medical School (HMS) Center for Nervous System Repair, the report's senior author. "In addition to providing insight into the development and circuit formation of this critical population of neurons, these results might lead to the future ability to treat motor neuron disorders and spinal cord injuries."

Although their cell bodies are located in the brain, CSMN axons extend down to the neurons they control in the spinal cord ?extending as far as three feet in adult humans. These neurons degenerate in ALS and related disorders, and their damage contributes to loss of motor function in spinal cord injuries. Since they are embedded among hundreds of other types of neurons in the cerebral cortex, it has been difficult to study CSMN, and little has been known about cellular and molecular factors that control their growth and development. In order to study growth factor controls over these cells, Mack lis and Hande Ozdinler, PhD, a postdoctoral fellow in his laboratory, developed a new way of isolating pure populations of CSMN in culture and found that IGF-1 was a prime candidate for control over CSMN development.

Using these purified neurons, they then showed that two ways of applying IGF-1 ?generally adding it to culture dishes or placing IGF-1-coated microbeads right next to CSMN cell bodies ?both increased the growth of axons by 15- to 20-fold, reaching the very fast rates previously seen only during initial development. Blocking the interaction between IGF-1 and its receptor reduced axon growth to control levels, confirming that the IGF-1 pathway is critical to the enhancement effect.

Experiments with another type of neuron and with several different growth factors verified that axonal growth was stimulated only by IGF-1 and only in CSMN. The researchers also showed that IGF-1 enhancement of axonal growth operates separately from the growth factor's known support of neuronal survival. Tests in living developing mice showed that blocking the IGF-1 pathway in the spinal cord prevented the growth of CSMN axons, which confirmed the applicability of the in vitro experiments to living mammals.

"The role of IGF-1 as a potent and specific enhancer of CSMN axon growth is highly relevant to our understanding of this critical population of neurons. These findings are a first step that may someday lead to ways of treating the neuronal degeneration of diseases like ALS, regenerating cells for the treatment of spinal cord injury, and to the potential replacement of neurons using precursors or 'neural stem cells'," says Macklis, who is on the faculty at Harvard Medical School.

Source:Massachusetts General Hospital

Related biology news :

1. Growth in the sea comes down to a struggle for iron
2. Estrogen-like Component of Plastic Stimulates Growth of Certain Prostate Cancer Cells
3. Growth in biomass could put US on road to energy independence
4. Embryonic Stem Cells Treated With Growth Factor Reverse Hemophilia In Mice: UNC Researchers
5. Missing Receptor Molecule Causes Tumor Growth
6. Growth hormone is made in the brain, report scientists
7. Growth factor-promoting angiogenesis expressed in tumor cells and normal neurons
8. New Research Shows Artificial Light at Night Stimulates Breast Cancer Growth in Laboratory Mice
9. Growth hormone to boost athletic performance risks diabetes
10. Growth hormone is not the anti-aging bullet for healthy adults
11. Cracking the olfactory code in bees

Post Your Comments:

(Date:11/30/2015)... , Nov. 30, 2015  BIOCLAIM announced ... finalist in this year,s Fierce Innovation Awards:  Healthcare Edition, ... FierceHealthIT , FierceHealthcare , ... as a finalist in the category of "Privacy ... --> --> ...
(Date:11/26/2015)... 2015 Research and Markets ( ) ... Sensors - Technology and Patent Infringement Risk Analysis" ... --> Fingerprint sensors using capacitive technology ... fingerprint sensor vendor Idex forecasts an increase of 360% ... devices and of the fingerprint sensor market between 2014 ...
(Date:11/20/2015)... Connecticut , November 20, 2015 ... authentication company focused on the growing mobile commerce market ... CEO, Gino Pereira , was recently interviewed on ... interview will air on this weekend on Bloomberg ... Latin America . --> NXTD ) ("NXT-ID" ...
Breaking Biology News(10 mins):
(Date:11/25/2015)... Md. , Nov. 25, 2015  PharmAthene, Inc. ... Directors has adopted a stockholder rights plan (Rights Plan) ... net operating loss carryforwards (NOLs) under Section 382 of ... --> PharmAthene,s use of its NOLs ... "ownership change" as defined in Section 382 of the ...
(Date:11/25/2015)... Nov. 25, 2015  Neurocrine Biosciences, Inc. (Nasdaq: ... President and CEO of Neurocrine Biosciences, will be presenting ... New York . ... website approximately 5 minutes prior to the presentation to ... the presentation will be available on the website approximately ...
(Date:11/25/2015)... The Global Genomics Industry ... and in-depth study on the current state of ... ) , The report provides ... classifications, applications and industry chain structure. The Genomics ... including development trends, competitive landscape analysis, and key ...
(Date:11/24/2015)... Cepheid (NASDAQ: CPHD ) today announced ... conference, and invited investors to participate via webcast. ... December 1, 2015 at 11.00 a.m. Eastern Time ... December 1, 2015 at 11.00 a.m. Eastern Time ... York, NY      Tuesday, December 1, 2015 at ...
Breaking Biology Technology: