QElectroTech is an open source tool for drawing these types of diagrams. It consists of two tools: an element editor for creating schematic symbols and a diagram editor for creating your drawings.

Neural circuit diagrams show connections between neurons ... a network in which brain regions or individual neurons are the nodes and axonal connections are represented by directed edges.

If you want the procedure to determine the node placement, the network must be acyclic. This example illustrates the use of PROC NETDRAW to draw two networks that represent different schematic flows .