Now, researchers from the Johns Hopkins Bloomberg School of Public Health and Thomas Jefferson University have discovered a potential explanation to why these neurological symptoms may occur with manganese exposure. The study found that dopamine neurons in the brain of animals exposed to manganese do not release dopamine when stimulated, suggestive of a dysfunctional dopamine system even though the neurons do not show the damage present with Parkinson’s disease.
Dopamine is a key neurotransmitter necessary for normal motor function. In addition, the researchers found that effects of manganese exposure occurred at blood concentrations in the upper range of levels documented in children and adults with environmental or occupational exposure. The study is published in the online version of the journal Experimental Neurology.
Manganese is a metal used in welding, battery making and in other industrial settings. In Canada, it replaced lead as a gasoline additive. Manganese, in the form of MMT, is approved in the United States as a gasoline additive but is not in use. The symptoms of “manganism” include behavioral and memory disturbances as well as Parkinson’s-like symptoms. Tremors occur with movement as opposed to the resting tremors typical of Parkinson’s disease.
“These findings may provide an explanation for some of the differences between manganism and idiopathic Parkinson’s disease, as well as why patients with manganese-induced neurological symptoms do not seem to respond to traditional Parkinson’s therapies,” said the study’s lead author, Tomás R. Guilarte, PhD, a professor in the Department of Environmental Health Sciences at the Bloomberg School of Public Health.
For the study, researchers observed a group of animals that were given incremental levels of manganese. The animals were monitored for behavioral changes and Positron Emission Tomography (PET) was used to assess various markers of dopamine neurons in the brain. According to the study, in addition to decreased in vivo dopamine release, manganese exposure produced subtle deficits in behavior and fine motor function.
“More work is needed to understand the relationship between the changes in behavior and the alterations in the dopamine system,” explained Jay S. Schneider, professor of pathology, anatomy and cell biology at Thomas Jefferson University and co-author of the study.
“There are other aspects of manganese neurotoxicity that this on-going study is examining that are likely to change the way that we view the risk of manganese exposure today,” said Guilarte.
“Nigrostriatal dopamine system dysfunction and subtle motor deficits in manganese-exposed non-human primates” was written by Tomás R. Guilarte, Ming-Kai Chen, Jennifer L. McGlothan, Tatyana Verina, Dean F. Wong, Yun Zhou, Mohab Alexander, Charles A. Rohde, Tore Syversen, Emmanuel Decamp, Amy Jo Koser, Stephanie Fritz, Heather Gonczi, David W. Anderson and Jay S. Schneider.
Funding was provided by a grant from the National Institute of Environmental Health Sciences.
Public Affairs media contacts for the Johns Hopkins Bloomberg School of Public Health: Tim Parsons at 410-955-6878 or email@example.com.
Tim Parsons | EurekAlert!
NIST scientists discover how to switch liver cancer cell growth from 2-D to 3-D structures
17.11.2017 | National Institute of Standards and Technology (NIST)
High speed video recording precisely measures blood cell velocity
15.11.2017 | ITMO University
The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.
Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...
Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.
That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...
Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.
During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....
The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.
Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...
Pillared graphene would transfer heat better if the theoretical material had a few asymmetric junctions that caused wrinkles, according to Rice University...
15.11.2017 | Event News
15.11.2017 | Event News
30.10.2017 | Event News
17.11.2017 | Physics and Astronomy
17.11.2017 | Health and Medicine
17.11.2017 | Studies and Analyses