The mammalian brain constantly adapts to new experiences of the environment, and inhibitory circuits play a crucial role in this experience-dependent plasticity. A characteristic feature of inhibitory neurons is the establishment of electrical synapses, but the function of electrical coupling in plasticity is unclear. Here we show that elimination of electrical synapses formed by connexin36 altered inhibitory efficacy and caused frequency facilitation of inhibition consistent with a decreased GABA release in the inhibitory network. The altered inhibitory efficacy was paralleled by a failure of theta-burst long-term potentiation induction and by impaired ocular dominance plasticity in the visual cortex. Together, these data suggest a unique mechanism for regulating plasticity in the visual cortex involving synchronization of inhibitory networks via electrical synapses.