The National Institute of Environmental Health Sciences (NIEHS) has awarded Cornell insecticide toxicologist David Soderlund two grants, providing more than $2.5 million over five years, to study how insecticides affect human health.

The grants are among the largest single-investigator research grants ever awarded to a member of the faculty at the New York State Agricultural Experiment Station in Geneva, N.Y. Soderlund is professor of insecticide toxicology. The NIEHS is part of the National Institutes of Health.

The projects involve two chemical classes of insecticides, synthetic pyrethroids and pyrazoline-type insecticides, that target the sodium ion channel proteins of nerve membranes. These proteins play a critical role in the electrical signaling of nerve cells. The research is expected to provide new insights into mechanisms of insecticide toxicity that will aid in assessing human health risks associated with using these insecticides.

"Although each research project asks different research questions about a different chemical class of insecticides, the main research approaches, techniques and tools are common to both projects," said Soderlund. He added that the two grants will allow him to build a large research team, making both projects more productive than they would be individually.

For both projects, Soderlund will use cloned sodium channel genes to turn cultured cells into synthetic nerve cells. This technique avoids the use of experimental animals as a source of nervous tissue and has the added benefit of giving researchers precise knowledge of and control over the specific sodium channel proteins they are studying.

The synthetic nerve cell approach also provides the Soderlund laboratory with the means to address one of the most significant problems in toxicology: the need to extrapolate insecticide risks to humans from research with other organisms.

"The use of cloned genes and cell-expression systems provides us with access to information on insecticide action on human target proteins that is simply not available otherwise," said Soderlund.