The input-output relationship of neuronal networks depends both on their synaptic connectivity and on the intrinsic properties of their neuronal elements. In addition to altered synaptic properties, profound changes in intrinsic neuronal properties are observed in many CNS disorders. These changes reflect alterations in the functional properties of dendritic and somatic voltage- and Ca2+-gated ion channels. The molecular mechanisms underlying this intrinsic plasticity comprise the highly specific transcriptional or post-transcriptional regulation of ion-channel expression, trafficking and function. The studies reviewed here show that intrinsic plasticity, in conjunction with synaptic plasticity, can fundamentally alter the input-output properties of neuronal networks in CNS disorders.