Two-fold effects of inhibitory neurons on the onset of synchronization in Izhikevich neuronal networks Peng-Xiang Lin, Chong-Yang Wang and Zhi-Xi Wu Eur. Phys. J. B, 92 5 (2019) 113 Published online: 22 May 2019 DOI: 10.1140/epjb/e2019-100009-2