As a step towards creating evolutionary developmental neural networks on FPGAs, a bio-inspired cellular structure suitable for online routing of axons and dendrites on FPGAs based on a new digital spiking neuron model (introduced previously by the authors) is proposed here. This structure is designed to allow changing the routing of the dendrites and axons and formation/elimination of synapses on the fly by dynamic partial reconfiguration of the LUTs. The feasibility and techniques for implementing this structure on a Xilinx Virtex-5 FPGA are also studied.