No One's Paying Attention...But The Endless Stream of Studies Linking Thimerosal (Mercury) with Autism Continues

[jenniferm]

In yet another study by more well-established and well-respected researchers directly links Thimerosal (mercury) exposure with autism in yet another model system. This new study continues to build upon previous model systems linking Thimerosal (mercury) with brain pathology found in subjects diagnosed with an autism spectrum disorder.

 

The new study, "Intermingled Modulatory and Neurotoxic Effects of Thimerosal and Meruric Ions on Electrophysiological Responses to GABA and NMDA in Hippocampal Neurons" was published in the peer-reviewed Journal of Physiology and Pharmacology by investigators from the Wroclaw Medical University, Wroclaw, Poland, the Marie Curie Chairs Programme at the Department of Pharmacology and Physiology of the Nervous System, Institute of Psychiatry and Neurology, Warsaw, Poland, and the Department of Biology and Environmental Science, University of Cardinal Stefan Wyszynski, Warsaw, Poland funded by grants from the European Commission, the Foundation for Polish Science, and the Ministry of Science and Higher Education of Poland. Please, find a copy of the study attached to this email saved as Modulatory-Neurotoxic Effects of Thimerosal on GABA & NMDA in Hippocampal Neurons1.pdf in Adobe Acrobat Format.

 

This new study described [emphasis added], "Thimerosal (THIM), an organomercurial containing approximately 49% of mercury by weight, has been added for decades to medicinal products, including pediatric vaccines, without being sufficiently tested for its safety. This is surprising in view of the fact that all mercurials are highly toxic, particularly to developing organisms. In the past decade concerns emerged about the possibility that THIM from vaccines might contribute to certain neurodevelopmental disorders in children...Unfortunately, it is still added to pediatric vaccines in less developed countries, including Poland, potentially damaging the health of children."

 

These investigators then reported [emphasis added], "THIM is metabolized in the body to ethyl mercury (EtHg) and subsequently to inorganic mercury forms, which accumulate in tissues of vital organs, including the brain...the existing data indicate that in pharmacodynamics and toxicity THIM/EtHg does not differ significantly from methyl mercury (MeHg)..."

 

These investigators stated [emphasis added], "Many neurotoxic effects of thimerosal have been described, but its interaction with principal excitatory and inhibitory neurotransmiter systems is not known. We examined, using electrophysiological recordings, thimerosal effects on GABA and NMDA-evoked currents in cultured hippocampal neurons. After brief (3 to 10 min) exposure to thimerosal at concentrations up to 100 μM, there was no significant effect on GABA or NMDA-evoked currents. However, following exposure for 60-90 min to 1 or 10 μM thimerosal, there was a significant decrease in NMDA-induced currents (p<0.05) and GABAergic currents (p<0.05). Thimerosal was also neurotoxic, damaging a significant proportion of neurons after 60-90 min exposure; recordings were always conducted in the healthiest looking neurons."

 

These investigators concluded [emphasis added], "The results reveal complex interactions of thimerosal and mercuric ions with the GABAA and NMDA receptors...thimerosal works slowly, reducing both NMDA and GABA responses. The neurotoxic effects of both mercurials are interwoven with their modulatory actions on GABAA and NMDA receptors, which most likely involve binding to these macromolecules."