A commentary on Differential effects of excitatory and inhibitory heterogeneity on the gain and asynchronous state of sparse cortical networks by Jorge F. Mejias, Andre Longtin (2014). Front. Comput. Neurosci. 8:107. doi: 10.3389/fncom.2014.00107 Neurons in the brain exhibit a broad spectrum of heterogeneities even within a given morphological or physiological class. In a recent modeling study, Mejias and Longtin investigated the effects of heterogeneity in the voltage threshold for spike generation on the dynamics of random networks of excitatory and inhibitory neurons (Mejias and Longtin, 2014), hence extending their previous results on purely excitatory networks (Mejias and Longtin, 2012).