1. European Laboratory for Non‐Linear Spectroscopy Florence 50019 Italy
2. National Institute of OpticsNational Research Council Florence 50125 Italy
3. Department of PhysicsUniversity of Pisa Pisa 56127 Italy
4. Division of Physiology, Department of Experimental and Clinical MedicineUniversity of Florence Florence 50134 Italy
5. Division of Pharmacology, Department ‘NeuroFarBa’University of Florence Florence 50139 Italy
6. R. D. Berlin Center for Cell Analysis and ModelingUniversity of Connecticut School of Medicine Farmington CT 06030 USA
7. Neuroscience InstituteNational Research Council Padova 35121 Italy
8. Department of Biomedical SciencesUnivercity ot Padua Padua 35121 Italy
9. Department of Information EngineeringUniversity of Florence Via S. Marta 3 Florence 50139 Italy
10. Department of PhysiologyMcGill University Montreal Quebec Canada
11. Department of Physics and AstronomyUniversity of Florence Sesto Fiorentino 50019 Italy