A significantly lower proportion of non-CM mice treated with ET-1 were able to successfully complete this memory task when compared to PbN-infected mice treated with saline (Fig 9B; 86% in PbN infected mice vs. 25% in PbN+ET-1 mice; P < 0.001), supporting our theory that cognitive impairment in ECM is induced by ET-1. This evidence concerns the gene EDN1 and Cognitive impairment.