Chiara Cirelli

Chiara Cirelli is a Professor in the Department of Psychiatry at the University of Wisconsin–Madison. She received her medical degree and Ph.D. in Neuroscience from the University of Pisa, Italy. Dr. Cirelli’s research is aimed at investigating the fundamental mechanisms of sleep regulation by using a combination of molecular and genetic approaches. Together with her long-term collaborator, Dr. Giulio Tononi, she has developed a comprehensive hypothesis about the function of sleep, the synaptic homeostasis hypothesis, according to which sleep serves to renormalize synaptic strength, counterbalancing a net increase of synaptic strength due to plasticity during wakefulness. Without sleep, such progressive increase in synaptic strength would lead to unsustainable costs in terms of energy, space, and cellular supplies, would reduce the informativeness of neuronal signals, and would prevent further learning by bringing stronger synapses closer to their level of saturation. In short, according to this hypothesis sleep is the price to pay for brain plasticity during wakefulness.