Synchronization in Newman-Watts (NW) networks is studied in a Hindmarsh-Rose neuron dynamical system. The topological structures of some optimal synchronization networks are given. Numerical simulation results show that the synchronizability of the NW network is mainly determined by the distribution of coupling points in coupling space. The network with even distribution of coupling points generally has the strongest synchronizability. For a given number of edges there may exist some optimal synchronization networks with different topological structures. Optimal synchronization network has the strongest synchronizability, homogeneous degree distribution and better symmetry. However, its symmetry is not necessarily best. In general, optimal synchronization network is an irregular network. However, in the minor cases, the regular network may be an optimal synchronization network. A new type of network, the ergodic network, is introduced in this paper, and it has strong synchronizability as well as the characteristics of the optimal synchronization network.