Gap junctions play important roles in the exchange of information and metabolites in the nervous system. These roles are highlighted by peripheral neuropathy (X-linked dominant Charcot-Marie-Tooth disease) that is associated with mutations in a gap-junction protein (connexin32), resulting in loss of function, and by somatic dysfunctions where changes in expression, organization or function of gap junctions are associated with neuronal hyper- or hypoexcitability. In this review, the causes and consequences of this gap-junction-related peripheral neuropathy and other pathological conditions of the nervous system, where dysfunctions of junctional communication are considered to play a casual role, are considered.