Navigation Links
A New Focus For The Mechanism Of Nerve Growth

Researchers at Yale shed new light on the mechanism of nerve cell growth by identifying novel functions for a molecular "motor" protein, myosin-II, according to an //article in the March issue of Nature Cell Biology. As nerve cells develop or attempt to recover after damage, they extend growth cones, highly flexible extensions that act as environmental sensors. Growth cones use the information they gather to direct advance of the nerve cells and it has long been known that such advance depends on the coordinated assembly of actin filament networks. This study implicates the molecular motor, myosin II, as a key part of the process of recycling the actin networks and ultimately sensing and directing nerve growth.

Proteins in the Myosin family function as molecular motors; the most familiar myosins power contraction in heart and skeletal muscles. Myosin II motors are involved in functions such as directed cell movement, cell division and wound closure. While skeletal myosins have been studied in detail, non-muscle myosins are just beginning to be understood and this work identifies a new role for them. The researchers, led by Paul Forscher, professor of molecular, cellular and developmental biology at Yale used a technique called fluorescent speckle microscopy, or FSM, that let them directly see actin filament assembly, disassembly and movement in living cells. They used FSM to monitor actin dynamics in nerve cells treated with a new drug called blebbistatin, that relaxes non-muscle myosin II and effectively blocks processes such as cell division. "Past research has focused on how actin structures are assembled at the leading edges of motile cells," said Forscher. "Instead, this paper investigates turnover or recycling of the actin networks. As the complement to actin network assembly, recycling is necessary to prevent actin buildup that could actually impede neuronal advance." Forscher likened actin networks in the growth cone to a molecular trea dmill that is constantly being assembled at the leading edge and moved rearward, powered by a myosin II motor located at its back end. But, the networks making up this actin treadmill are constantly being recycled at the back end, and actin molecules are freed to complete a "virtual belt" cycle and be used again.

"Surprisingly, growth cones of nerve cells rapidly doubled in width when myosin II was blocked by blebbistatin," said Forscher. "FSM see that this was caused by inefficient recycling of actin filaments at the back end of the actin network treadmill."

Recycling of actin bundles at the ends of structures called filopodia was most strongly affected. This is important because filopodia are thought to play a key sensory role in growth cone guidance -- suggesting actin filament recycling and signaling may be intimately related.

The team is now investigating the implications of these findings for control of nerve growth, with particular interest in repair of spinal cord nerves after injury. Yale co-authors on the paper are Nelson A. Medeiros and Dylan T. Burnett. Support for the project was from the National Institutes of Health grant and the Nikon Partners-in-Research Program.

Citation: Nature Cell Biology: March 2006
Contact: Janet Rettig Emanuel
Yale University


Related medicine news :

1. Focus on DNA transcription
2. Focused Treatment For Childhood Cancer
3. Focussed treatment for Hodgkins disease
4. World Heart Day To Focus On Ideal Body Weight And Shape To Reduce Risk Of Heart Disease
5. Now Employers Focus On Employees Mental health
6. JRRD Focuses On Issues Such As Spinal Cord Injury and Prosthetics
7. UN research symposium To Focus on Open source and Open Medicine
8. Biocon To Shift Focus On Innovation To Accelerate Growth
9. UK Has To Focus On Bridging the Gap between Healthcare Professionals and Patients
10. The Australian Medical Association To Focus On Health Of Aborigines
11. Ritalin Could Help In Focussing The Mind
Post Your Comments:

(Date:10/13/2017)... ... , ... Many families have long-term insurance that covers care for a family ... for care if the client has a cognitive impairment diagnosis. , “What this ... often waived, so the benefits from their insurance start immediately,” said Mechell Vieira, owner ...
(Date:10/13/2017)... ... October 13, 2017 , ... Yisrayl Hawkins, Pastor and Overseer at The House ... most popular and least understood books in the Holy Scriptures, Revelation. The Book of ... baffled scholars for centuries. Many have tossed it off as mere rubbish, but Yisrayl ...
(Date:10/13/2017)... ... October 13, 2017 , ... “America On The Brink”: the ... “America On The Brink” is the creation of published author, William Nowers. Captain ... As a WWII veteran, he spent thirty years in the Navy. Following his ...
(Date:10/12/2017)... ... October 12, 2017 , ... The company has ... today’s consumer and regulatory authorities worldwide. From Children’s to Adults 50+, every formula ... the highest standard. , These products are also: Gluten Free, Non-GMO, Vegan, ...
(Date:10/12/2017)... ... October 12, 2017 , ... ... system that we intend to develop to enable prevention of a major side ... severe hearing loss, especially in pediatric patients. For cisplatin, hearing loss is FDA ...
Breaking Medicine News(10 mins):
(Date:10/4/2017)... Oct. 4, 2017 OBP Medical ... illuminating medical devices, today announced regulatory approval from ... Agency (or Agência Nacional de Vigilância Sanitária (ANVISA)) ... cordless surgical retractor with integrated LED light source ... illumination and exposure of a tissue pocket or ...
(Date:10/2/2017)... -- The Rebound mobile app is poised to become a ... of prescription drug addiction. The app empowers users to develop ... down their dosage in a safe, controlled manner while maximizing ... first 100,000 people to sign up will enjoy 3 months ... ...
(Date:9/25/2017)... , Sept. 25, 2017   Montrium , ... File solutions, today—from the IQPC Trial Master Files ... , NL)—announced that EastHORN Clinical Services has selected ... programs and TMF management. EastHORN, a leading European ... platform to increase transparency to enable greater collaboration ...
Breaking Medicine Technology: