Researchers present evidence of mercury’s effect on brain neurons

Researchers present evidence of mercury’s effect on brain neurons

http://www.fp.ucalgary.ca/unicomm/Gazette/April4-01/mercury.htm

A University of Calgary Faculty of Medicine research team has found that exposure to mercury causes degeneration of brain neurons in animals.

The scientific findings are being published in a cover story in the April edition of the British journal NeuroReport. The researchers’ academic paper is supported by a time-lapse video recorded from a microscope camera showing how neurons degenerate when they are exposed to mercury.

"Our study illustrates how mercury ions alter the cell membrane structure of developing neurons," says Fritz Lorscheider, physiology and biophysics. "This discovery provides visual evidence of our previous findings that mercury produces a molecular lesion in the brain."

The research paper, co-authored by Lorscheider and U of C professor Naweed Syed as well as medical student Christopher Leong, looks at brain neurons from snails. The researchers added mercury ions to cell cultures of developing neurons and observed the neurons undergoing rapid degeneration. Nerve processes in snails and other animals, specifically the microtubules in neurons, are similar to those of humans.

The team has identified how this degeneration takes place:

• mercury ions attach to a neuron, causing its microtubules to disassemble or break down and, ultimately, leave that neuron stripped of

• its protective membrane

• some of these stripped neurons then form aggregates

• these aggregates are damaged neurons that are clumped or tangled together

• the damaged neurons cease to function as healthy neurons would

Other metals – aluminum, lead, cadmium and manganese – did not produce this type of degeneration.

"Mercury has long been known to be a potent neurotoxic substance, whether it is inhaled as vapour or consumed in the diet as a food contaminant," says Lorscheider. "This research provides visual confirmation of that."

Medical research laboratories, over the past 15 years, have established that dental amalgam tooth fillings are a major contributor to mercury body burden. In 1997 research done by Lorscheider and colleagues at the universities of Calgary and Kentucky demonstrated that mercury vapour inhalation in rats produced a molecular lesion in the brain - similar to a lesion seen in 80% of human Alzheimer-diseased brains.

Video support for researcher’s findings

Peer-reviewed animation?

When U of C professors Fritz Lorscheider and Naweed Syed co-authored their research paper on the effects of mercury on neurons, one of the most compelling proofs they had was a five-minute video that showed those effects.

The video combined state-of-the art animation and time-lapse videography to irrefutably demonstrate their findings.

The video, created by the Advanced Media for Learning group from the Learning Commons, used the same animation software used in Hollywood films such as The Matrix.

"Dr. Lorscheider called and asked us to put together the animation to help explain mercury’s effect," says Dave Rittenhouse. "We just filled in the blanks."

However, the video was more than just a prop to gather media attention. When Lorscheider submitted the paper to the British journal NeuroReport, which eventually published it, he added the video as an accompanying document, making it the first time that a piece of animation was subjected to the peer-review process, as far as Rittenhouse knows.

Rittenhouse foresees the animation technology being more useful for researchers.

"It’s a visualization technology. Researchers can use it to visualize scientific and research data."

 http://www.fp.ucalgary.ca/unicomm/Gazette/April4-01/mercury.htm