Reprinted from Proceedings of Third Italian Workshop on Parallel Architectures and Neural Networks, Vietri Sul Mare (Salerno), E. R. Caianiello ed., World Scientific, 1990. Dynamic Topology Neural Network M. Marchesi, G. Orlandi (*), F. Piazza, G. Pignotti and A. Uncini, Dipartimento di Elettronica e Automatica - University of Ancona Via Brecce Bianche, 60131 Ancona-Italy. Fax:+39 (071) 2204464 - email: aurel@ieee.org Internet: http://nnsp.eealab.unian.it/ (*) Dipartimento INFOCOM Università di Roma “La Sapienza” Via Eudossiana, 18, 00184 Roma-Italy _______________________________________