NO SYNTHASE-II IS TRANSIENTLY EXPRESSED IN EMBRYONIC MOUSE OLFACTORY RECEPTOR NEURONS

Among three NO synthase (NOS) isoforms only the inducible NOS-II was l ocalized in developing olfactory receptor neurons of the mouse. First NOS-II immunoreactive receptor cells including their processes were de tected by embryonic day 11 when the olfactory pit starts to invaginate . Cellular staining lasted until embryonic day 16, and was reduced dur ing the next few days. At embryonic day 20 no reactivity was found in the olfactory epithelium, whereas centripetal nerve fibers remained po sitive. This transient expression of NOS-II implies a role for the dif ferentiation of early olfactory receptor neurons and synaptic plastici ty. (C) 1997 Elsevier Science Ireland Ltd.