Less means more: inhibition of spontaneous firing triggers persistent increases in excitability.

Modulation of intrinsic excitability is an alternative to classical synaptic plasticity for implementing activity-dependent changes in neuronal networks. In this issue of Neuron, Nelson et al. reveal a new form of plasticity of intrinsic excitability that can be triggered rapidly when synaptic inhibition reduces spontaneous firing, resulting in persistent enhancement of firing rate and neuronal gain.