The influence of the menstrual cycle on the fe...( What influence does the variation in e...),Health

What influence does the variation in estrogen level have on the activation of the female brain? Using functional Magnetic Resonance Imaging, Jean-Claude Dreher, a researcher at the Cognitive Neuroscience Center (CNRS/Universit Lyon 1), in collaboration with an American team from the National Institute of Mental Health (Bethesda, Maryland) directed by Karen Berman, has identified, for the first time, the neural networks involved in processing reward-related functions modulated by female gonadal steroid hormones. This result, which was published online on January 29, 2007 on the PNAS website, is an important step in better comprehension of certain psychiatric and neurological pathologies.

The human brain has a recompense system that predicts different types of reward (food, money, drugs). The normal functioning of this system plays a fundamental role in many cognitive processes such as motivation and learning. This reward system, composed of dopaminergic neurons1 situated in the mesencephalon (a very deep region of the brain) and their projection sites2, is crucial for neural coding of rewards. Its dysfunction can result in disorders such as addictions and is also implicated in various psychiatric and neurological pathologies, such as Parkinson's disease and schizophrenic disorders. Many studies on animals prove that the dopaminergic3 system is sensitive to gonadal steroid hormones (estrogen, progesterone). For example, female rats self-administer cocaine (a drug that acts on the dopamine system) in higher doses after estrogens have been administered to them. The influence of gonadal steroid hormones on the activation of the reward system remained to be studied in humans. A better knowledge of this influence should make for better understanding of the differences between men and women, particularly as observed in the prevalence of certain psychiatric pathologies and in vulnerability to drugs, (for which the dopaminergic system plays an important role.) It
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Contact: Monica McCarthy
monica.mccarthy@cnrs-dir.fr
33-196-445-191
CNRS
26-Feb-2007