Presynaptic coupling by electrical synapses coordinates a rhythmic behavior by synchronizing the activities of a neuron pair

Central pattern generators produce rhythmic behaviors that occur on a variety of timescales. Here, using a simple behavioral circuit that repeats every 50 s in Caenorhabditis elegans, we show that electrical synapses composed of the gap junction protein INX-1/innexin are necessary for the precise and accurate timing of the behavioral outputs that are controlled by a biological clock. Electrical synapses do so by both promoting synchronized activation of a pair of coupled neurons in response to the signals from the clock and by inhibiting their inappropriate activation when clock signaling is low. Our findings represent one of the first examples of how the execution of a rhythmic behavior is shaped by electrical synapses through coordinating the activities of coupled neurons.