1. Department of Biomedical Sciences, G. D'Annunzio University of Chieti, 66013 Chieti
2. Ageing Research Center, Ce.S.I., G. D'Annunzio University of Chieti, Chieti
3. Dept of Biology, University of Bologna, 40126 Bologna
4. Dept of Biomedical Sciences, B.R.A.I.N. Centre for Neuroscience, University of Trieste, 34127 Trieste, Italy