1 Department "G.F. Ingrassia", Section of Neurosciences, University of Catania, Via Santa Sofia, 78, 95123 Catania, Italy. Electronic address: pennigi@unict.it.
2 Department "G.F. Ingrassia", Section of Neurosciences, University of Catania, Via Santa Sofia, 78, 95123 Catania, Italy.
3 Department of Neurology I.C., "Oasi" Institute for Research on Mental Retardation and Brain Aging (I.R.C.C.S.), Via Conte Ruggero, 73, 94018 Troina (EN), Italy.