Defining the electrical synapse.

Electrical and chemical synapses together shape neural circuits critically required for the processing of information by the nervous system. Owing to the relative simplicity of the mechanism of action mediating electrical coupling between neurons, electrical transmission is generally perceived as static and results solely from the function of intercellular channels at structures known as 'gap junctions'. However, electrical synapses are dynamic structures that exhibit changes in their synaptic strength, indicating a need for a deeper understanding of the determinants regulating their structure and plasticity. Mounting evidence indicates that, beyond the intercellular channels, electrical transmission is supported by sophisticated synaptic structures with an unanticipated complexity in their molecular organization, requiring a new, broader definition of electrical synapses.