Until now, the brain was assumed to be a side player in diabetes. “For the most part, diabetes researchers have not been looking at the brain,” said C. Ronald Kahn, the Mary K. Iacocca professor of medicine and president of Joslin Diabetes Center. But a report appearing in the Sept. 22, 2000, Science suggests that defects in the brain’s ability to respond to insulin could contribute to some of the central symptoms of adult, or Type II, diabetes, including obesity and lowered fertility. The findings, made in mice, contribute to our understanding of the brain’s role. More importantly, if confirmed in humans, the discovery could call into question a longstanding dogma about how insulin resistance, the hallmark of diabetes, paves its ruinous course through the body. The new findings by Kahn and his colleagues are already pointing to an alternative view of the disease which, if confirmed, could lead to new diabetes treatments.