Signal Propagation Along Unidimensional Neuronal Networks

1 Departments of Physics of Complex Systems and of 2 Neurobiology, The Weizmann Institute of Science, Rehovot, Israel Submitted 11 March 2005; accepted in final form 17 July 2005 Dissociated neurons were cultured on lines of various lengths covered with adhesive material to obtain an experimental model system of linear signal transmission. The neuronal connectivity in the linear culture is characterized, and it is demonstrated that local spiking activity is relayed by synaptic transmission along the line of neurons to develop into a large-scale population burst. Formally, this can be treated as a one-dimensional information channel. Directional propagation of both spontaneous and stimulated bursts along the line, imaged with the calcium indicator Fluo-4, revealed the existence of two different propagation velocities. Initially, a small number of neighboring neurons fire, leading to a slow, small and presumably asynchronous wave of activity. The signal then spontaneously develops to encompass much larger and further populations, and is characterized by fast propagation of high-amplitude activity, which is presumed to be synchronous. These results are well described by an existing theoretical framework for propagation based on an integrate-and-fire model. Address for reprint requests and other correspondence: O. Feinerman, Department of Physics of Complex Systems, The Weizmann Institute of Science, Rehovot, Israel 76100 (E-mail: feiner{at}wisemail.weizmann.ac.il )