[1] Univ Roma Tor Vergata, Dept Neurosci, I-00133 Rome, Italy
[2] Univ Cagliari, Dept Expt Biol Bernardo Loddo, I-09100 Cagliari, Italy
[3] Scripps Res Inst, Dept Neuropharmacol, La Jolla, CA 92037 USA
[4] Vet Affairs Med Ctr, Dept Psychiat, Res Serv, San Diego, CA USA