1 European Laboratory for Non-Linear Spectroscopy, 50019 Florence, Italy.
2 National Institute of Optics, National Research Council, 50019 Florence, Italy.
3 Division of Physiology, Department of Experimental and Clinical Medicine, University of Florence, 50121 Florence, Italy.
4 Division of Pharmacology, Department "NeuroFarBa," University of Florence, 50139 Florence, Italy.
5 Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg-Bad Krozingen, Faculty of Medicine, University of Freiburg, 79110 Freiburg, Germany.
6 Department of Physics and Astronomy, University of Florence, 50019 Florence, Italy.
7 European Laboratory for Non-Linear Spectroscopy, 50019 Florence, Italy; sacconi@lens.unifi.it.