This result indicates that Cx43 hemichannel function is deleterious in ischemia and suggests that the increase in infarct volume observed in mice with astrocytic Cx43 deficiency (Nakase et al., 2004) obeys to a neuroprotective role of Cx43-mediated gap junction channels that overrides the neurotoxic action of hemichannels. Here, GJA1 is linked to ischemia.