The study, which is reported in the January 2005 issue of Environmental Toxicology and Pharmacology, is the first step toward understanding how exposure to BCE might affect human nerve cell development--knowledge that may one day provide clues about such neurological mysteries as autism spectrum disorder or attention deficit hyperactivity disorder.
To test her hypothesis, MBL scientist Carol Reinisch and her colleagues treated developing surf clam embryos (Spisula solidissima) with different combinations of BCE and studied their effects on nerve cell growth. "On a cellular level, clam neurons are extremely useful in studying basic mechanisms of cell development," says Reinisch, an expert in PCB-induced neurotoxicity.
"Of the different combinations and strengths of BCE components tested, we found that all three together induce the greatest adverse response. Treating the embryos with the triple mixture resulted in increased production of a subunit of an enzyme called protein kinase A (PKA), which previous research suggests plays a role in neural development," says Reinisch. "Fluctuations in PKA may influence not only neuronal maturation but also how neuronal networks are constructed during development," she says. Alterations of this enzyme may affect neural development and neural connections by activating or inactivating other proteins.