Heterogeneity of nitric oxide synthase-containing neurons in the mouse main olfactory bulb

Neurosci Res. 2007 Feb;57(2):165-78. doi: 10.1016/j.neures.2006.10.005. Epub 2006 Nov 28.


The distribution and structural features of nitric oxide [corrected] synthase (NOS) containing intrinsic neurons were studied in the mouse main olfactory bulb (MOB). NOS positive neurons were heterogeneous, including some subpopulations of periglomerular cells, granule cells, interneurons in the external plexiform layer, superficial and deep short-axon cells and stellate cells. NOS positive periglomerular cells were frequently calretinin immunoreactive and, although rarely, calbindin positive. Importantly, some middle and external tufted cells were also confirmed to be NOS positive, some of which were also cholecystokinin (CCK) positive. Retrograde tracer experiments showed that some NOS positive tufted cells, which were also CCK positive, constitute the intrabulbar association system and the projection system to the olfactory tubercle. In addition, another particular subpopulation of NOS positive neurons with no or little CCK immunoreactivity appeared to project to areas covering the dorsal endopiriform nucleus, claustrum and insular cortex. Furthermore, diverse types of neurons other than mitral/tufted cells were also suggested to be projection neurons of the MOB. The present study revealed the diversity of NOS positive neurons in the mouse MOB and further revealed that they were different from those reported previously in the rat MOB in structural and chemical properties.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Calbindin 2
  • Cholecystokinin / metabolism
  • Immunohistochemistry
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Microscopy, Immunoelectron
  • Neurons / classification*
  • Neurons / enzymology*
  • Neurons / ultrastructure
  • Nitric Oxide Synthase / metabolism*
  • Olfactory Bulb / cytology*
  • Olfactory Pathways / cytology*
  • Olfactory Pathways / metabolism
  • Olfactory Pathways / ultrastructure
  • S100 Calcium Binding Protein G / metabolism
  • Stilbamidines / metabolism


  • 2-hydroxy-4,4'-diamidinostilbene, methanesulfonate salt
  • Calb2 protein, mouse
  • Calb2 protein, rat
  • Calbindin 2
  • S100 Calcium Binding Protein G
  • Stilbamidines
  • Cholecystokinin
  • Nitric Oxide Synthase