Discrete stages of formation of nervous plexuses in the culture of isolated neurons of a mollusc were analyzed autonomically. Area of plexus expansion (S1) and area, occupied by nerve structures (neurites and neuron bodies) were determined. It was demonstrated that despite intensive radial growth of peripheral neurites and S1 growth the density of plexus (S2/S1) was not changed. Relative acceleration of plexus expansion (as compared to S2 growth) registered on 40th and 50th hrs of cultivation indicates the absence of necessary cells in the plexus and development of contacts with adjacent local plexuses. Scanning of lamellar structures revealed submembranous aggregation of cytoskeleton apart from longitudinally directed cytoskeletal bands, which prevents one of the ways of neurite ramification. Elimination of lamellae between cytoskeletal bundles leads to formation of several neurites.