There has been rapid progress in molecular modeling of LGICs in recent years. The convergence of improved software for molecular mechanics/dynamics, techniques of chimeric substitution and site-directed mutations, and the first X-ray structures of transmembrane ion channels will make it possible to build reasonable models of neuronal ion channels well in advance of publication of their crystal structures. These models will not only serve as guides for future site-directed mutagenesis, but they will also be a starting point for understanding the dynamics of ion channel gating.