“…For example, NOS is present in the most primitive of metazoans, the sponges, as well as mollusks, annelids, cnidarians and arthropods [Leake and Moroz, 1996;Moroz and Gillette, 1996;Korneev et al, 1998;Giovine et al, 2001;Kitamura et al, 2001;Rast, 2001;Watson et al, 2001;Bullerjahn and Pfluger, 2003;Christie et al, 2003;Moroz et al, 2004;Kurylas et al, 2005]. NOS-immunoreactivity (NOS-ir) in non-mammalian vertebrate brains has been detected in various fishes [Brüning et al, 1995;Villani et al, 2001;Bordieri et al, 2003;Singru et al, 2003;Ando et al, 2004;Masini et al, 2005], reptiles [Brüning et al, 1994b;Smeets et al, 1997;Haverkamp et al, 2000], and birds [Brüning et al, 1994a;Garcia-Calero et al, 2002;Balthazart et al, 2003].…”