Distribution of VIP- and NPY-like immunoreactivities in rat main olfactory bulb.
The distribution of vasoactive intestinal peptide (VIP)- and neuropeptide Y (NPY)-like immunoreactivities in the Sprague-Dawley rat main olfactory bulb was analyzed using the peroxidase-antiperoxidase light microscopic immunocytochemical technique. VIP-like immunoreactivity was most prominently localized within a large number of intermediate-sized neurons whose perikarya and extensively branched varicose processes remained confined to the external plexiform layer (EPL). A few small short-axon type neurons in the mitral cell layer and granule cell layer (GRL) and even fewer large neurons in the glomerular layer (GL)/EPL border region contained immunoreactivity for VIP as well. Neuropeptide Y-like immunoreactivity (NPY-I) was principally localized within sparsely distributed large multipolar neurons of the deep GRL and within axons distributed with diminishing density from deep to superficial GRL. In addition, dense NPY-I was localized within very few large superficial short-axon type neurons of the GL/EPL border region. The restricted laminar and cellular distribution of NPY-I and VIP-I suggests that both peptides may act to modulate granule cell activity, and therefore, indirectly, olfactory bulb output.
D000818:Animals; D001369:Axons / Q000032:analysis; D005260:Female; D007106:Immune Sera; D007124:Immunoenzyme Techniques; D008297:Male; D009419:Nerve Tissue Proteins / Q000032:analysis*; D009478:Neuropeptide Y; D009830:Olfactory Bulb / Q000032:analysis* / Q000166:cytology; D051381:Rats; D011919:Rats, Inbred Strains; D013194:Staining and Labeling; D014660:Vasoactive Intestinal Peptide / Q000032:analysis*
D007106:Immune Sera; D009419:Nerve Tissue Proteins; D009478:Neuropeptide Y; D014660:Vasoactive Intestinal Peptide