fMRI of Hormonal Variation in Cognitive Affective Processing

With National Science Foundation support, Dr. Canli and colleagues will conduct a three-year investigation into how changes in hormonal state affect brain activation patterns during cognitive and emotion-related psychological processes. Specifically, functional magnetic resonance imaging (fMRI) will be used to record brain activation patterns in response to cognitive and emotional stimuli in two groups of women. One group will consist of women who will be scanned at different times in the naturally occurring menstrual cycle. The other group will consist of post-menopausal women who will be scanned during a three-week period of estrogen/progesterone or placebo (sugar pill) administration. The results of these studies will illuminate our understanding of hormonal regulation of mood and the neural structures that underlie these states. Very little is known about some fundamental aspects of brain function as a function of gender, as suggested by a call by the National Academy of Sciences to devote more biomedical research to sex differences. This work will not only fill a knowledge gap in basic neuroscience, but may also guide future clinical studies to understand the striking sex differences in the incidence of mood disorders such as depression, which strikes as many as four times as many women than men. Furthermore, the proposed work may be of benefit for postmenopausal women weighing the consequences of hormone replacement therapy on brain function. Such decisions will likely be contemplated by large segments of the population, as it is estimated that the average woman will spend at least half her adult life with decreased levels of circulating estrogen.