A scientist at the Gladstone Institutes has identified how the lack of a brain chemical known as dopamine can rewire the interaction between two groups of brain cells and lead to symptoms of Parkinson's disease. This discovery offers new hope for treating those suffering from this devastating neurodegenerative disease.
In a paper being published online today in Neuron, Gladstone Investigator Anatol Kreitzer, PhD, identifies how the loss of dopamine alters the wiring of a small group of brain cells, kicking off a chain of events that eventually leads to difficulties controlling movement—a hallmark of Parkinson's disease. More than a half-million people suffer from Parkinson's in the United States, including the boxer Muhammad Ali and the actor Michael J. Fox.
"The development of truly effective and well-tolerated therapies for Parkinson's has proven difficult," said Lennart Mucke, MD, who directs neurological disease research at the Gladstone Institutes, a leading and independent biomedical-research organization. Dr. Mucke is also a professor of neurology and neuroscience at the University of California, San Francisco (UCSF), with which Gladstone is affiliated. "Dr. Kreitzer's discovery sheds new light on the intricate processes that underlie motor problems in this disabling condition and will hopefully lead to the development of more effective medicines."
Normally, two types of brain cells called medium spiny neurons, or MSNs, work together to coordinate body movements, with one type acting like a gas pedal and the other as a brake. It has been thought that a reduction in dopamine, an important chemical in the brain, throws off the balance between the two opposing MSN forces, leading to problems with movement. But Dr. Kreitzer wondered if another factor might also be involved. To better understand the relationship between dopamine and MSNs in people with Parkinson's, Dr. Kreitzer artificially removed dopamine from the brains of laboratory mice and monitored the specific changes in the brain that followed.
Just as happens in humans, the mice without dopamine began to experience the motor symptoms of Parkinson's, including tremors, problems with balance and slowed movement. But Dr. Kreitzer found that decreased dopamine levels didn't just throw off the balance between the two types of MSNs, as was already known, but they also changed the interaction between MSNs and another group of neurons called fast-spiking neurons, or FSNs.
Dr. Kreitzer's experiments showed that under normal circumstances, FSNs connect to both types of MSNs in a similar way. But without dopamine, the signaling between the FSN circuits gets rewired and the neurons begin to target one type of MSN over the other. Dr. Kreitzer used computer simulations to show that this small shift disrupts the timing of MSN activity, which is key to normal movement. Ultimately, this rewiring may be an important factor in the development of Parkinson's motor problems.
"Our research has uncovered how an entirely different group of neurons can play a role in the development of Parkinson's disease symptoms," said Dr. Kreitzer, who is also an assistant professor of physiology and neurology at UCSF. "We hope to target the changes among these neurons directly with drug therapies, in order to help relieve some of Parkinson's most debilitating symptoms."
Other scientists who participated in the research at Gladstone include Aryn Gittis, Giao Hang, Eva LaDow and Steven Finkbeiner. Funding for the research came from a wide variety of organizations, including the Tourette Syndrome Association, the National Institutes of Health, the Pew Biomedical Scholars Program, the W.M. Keck Foundation and the McKnight Foundation.
Dr. Kreitzer is an Assistant Investigator at the Gladstone Institute of Neurological Disease and an Assistant Professor of Physiology and Neurology at UCSF. The Kreitzer lab focuses on understanding the neural mechanisms that control motor planning, learning and movement. Their long-term goal is to understand how circuitry and activity in the brain shapes motor behavior and how disorders such as Parkinson's disease and Huntington's disease affect circuits in the brain.
About the Gladstone Institutes
Gladstone is an independent and nonprofit biomedical-research organization dedicated to accelerating the pace of scientific discovery and innovation to prevent illness and cure patients suffering from cardiovascular disease, neurological disease, or viral infections. Gladstone is affiliated with the University of California, San Francisco.
Anne Holden | EurekAlert!
Correct connections are crucial
26.06.2017 | Charité - Universitätsmedizin Berlin
One gene closer to regenerative therapy for muscular disorders
01.06.2017 | Cincinnati Children's Hospital Medical Center
An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.
Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...
Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.
Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...
Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.
As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...
Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.
With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...
Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine
Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...
19.06.2017 | Event News
13.06.2017 | Event News
13.06.2017 | Event News
26.06.2017 | Life Sciences
26.06.2017 | Physics and Astronomy
26.06.2017 | Information Technology