Peter Paschke, Ralf Moeller, Dept of Neuroinformatics, T.U. Ilmenau, Gustav-Kirchoff-Str 2, D-98684 Ilmenau, Germany, and Inst. Computer Science, Univ of Zurich, Winterthurstr 190, CH-8057 Zurich, Switzerland Neurons of the cortical tissue in a mammalian brain are connected in an extremely sparse and random fashion. The paper uses findings of neuroanatomy to model this special connection scheme and presents an efficient method for a parallel simulation of such networks on a CNAPS SIMD neurocomputer. A considerable speedup in comparison to sequential computation is achieved.