iNOS knockout mice show increased expression of contextual fear conditioning and impaired extinction of fear memory: involvement of nNOS - Lisboa, S. F.; Gomes, F. V.; Cunha, Thiago Mattar; Guimarães, Francisco Silveira; Joca, Sâmia Regiane Lourenço; Resstel, L. B. (Neuropharmacology Conference, 2011)