Dopamine Prompts Nerve Tissue to Regrow

Dopamine, a neurotransmitter, has been integrated into a polymer that can help nerve tissue reconnect to the organ it once served.

Researchers at the Georgia Institute of Technology (Georgia Tech, Atlanta, USA) and Emory University (Atlanta, USA) discovered that they could integrate dopamine into a polymer to stimulate nerve tissues to send out new connections. The new polymer was recognized by the neurons when used on a small piece of nerve tissue and it stimulated extensive neural growth. The implanted polymer did not cause any tissue scarring or nerve degeneration, allowing the nerve to grow in a hostile post-injury environment. As the nerve tissue reformed, the polymer degraded.

Dopamine's structure, which contains two hydroxyl groups, was found to be vital for the material's neuroactivity. Removing even one group caused a complete loss of the biologic activity. The researchers determined that dopamine was more effective at differentiating nerve cells than the two most popular materials for culturing nerves--
polylysine and laminin. This ability means that the material with dopamine may have a better chance to successfully repair damaged nerves. The success of dopamine has encouraged the team to set its sights on other neurotransmitters. The findings were published in the November 7, 2006, edition of the Proceedings of the [U.S.] National Academy of Sciences (PNAS).

"We showed that you could use a neurotransmitter as a building block of a polymer,” said lead author Yadong Wang, an assistant professor in the department of biomedical engineering at Georgia Tech. "Once integrated into the polymer, the transmitter can still elicit a specific response from nerve tissues.”

The discovery is the first step toward the eventual goal of implanting the new polymer into patients suffering from neurologic disorders, such as Alzheimer's, Parkinson's, or epilepsy, to help repair damaged nerves. The team's next step is to verify findings that the material stimulates the reformation of synapses in addition to regrowth.



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Georgia Institute of Technology
Emory University