NADPH‐diaphorase active and calbindin D‐28k‐immunoreactive neurons and fibers in the olfactory bulb of the hedgehog (Erinaceus europaeus)

Abstract

The hedgehog, a macrosomatic insectivore with an extraordinary development of the olfactory structures, has a crucial value for any phylogenetic or comparative study in mammals. The distribution pattern and morphology of NADPH-diaphorase-active and calbindin D-28k-immunoreactive neurons were studied in the main and accessory olfactory bulbs of the hedgehog. NADPH-diaphorase (ND) staining was carried out by a direct histochemical method, and the calbindin D-28k (CaBP) immunoreaction by using a monoclonal antibody and the avidin-biotin-immunoperoxidase method. The possible coexistence of both markers was determined by sequential histochemical-immunohistochemical double labeling of the same sections. Specific neuronal populations were positive for both ND and CaBP markers. No cell colocalized both stains in the hedgehog olfactory bulb. A subpopulation of olfactory fibers, and a subpopulation of olfactory glomeruli, located on the medial side, were positive for ND. Surrounding both the ND-positive and ND-negative glomeruli, there were ND- and CaBP-positive periglomerular cells, the latter group being much more abundant. A subpopulation of superficial short-axon cells was CaBP positive but, contrary to what is observed in rodents, this neuronal type was always ND negative. In addition, three neuronal types were observed in the GL-EPL border after CaBP immunostaining. These neuronal types have not been previously described either in the hedgehog or in the rodent olfactory bulb. Horizontal cells and vertical cells of Cajal were also observed after both ND and CaBP labeling. Distinct groups of ND- and CaBP-positive cells, differing in size, shape, dendritic branching pattern, and staining intensity, were distinguished in the granule cell layer and in the white matter. The large and medium-sized cells were identified as a very heterogeneous population of deep short-axon cells, whereas a subpopulation of granule cells was ND positive. The accessory olfactory bulb showed ND staining in all vomeronasal fibers and glomeruli, and in subpopulations of periglomerular cells, granule cells, and deep short-axon cells. The CaBP immunolabeling was more restricted and located in subpopulations of periglomerular cells and in deep short-axon cells. These results indicate different and more complex ND and CaBP staining patterns in the hedgehog olfactory bulb than those previously described in rodents, including the presence of specific, chemically and morphologically defined new neuronal types.

A classification of NOergic neurons in the inferior colliculus of rat according to co-existence with classical amino acid transmitters

“…Recently several investigators have described the distribution of NOergic neurons in relation to aminergic neurons in different regions of the central nervous system, including the zona inserta 17) , prefrontal cortex 13) , medulla oblongata 21) , hippocampus 37) , cuneate nucleus 35) , olfactory bulb 1) , lateral geniculate nucleus 14) , spinal cord 31) , and cerebral cortex 36) . Nevertheless, little is known about the relationship between NO and neuroactive amino acids in the auditory nuclei.…”

“…Indeed, the above approach has been used widely for mapping NOS-containing (presumably NOergic) neurons in the central nervous system 3,38) . NADPH-d histochemistry has also been combined with immunohistochemistry to assess relationships between the distribu-tion of NO and traditional neurotransmitters in various regions of the CNS 1,14,30,35,37) . Several studies suggest that NO and NOS play a role in audition.…”

Organization of the Caudal Rhombencephalic Alar Plate of the Ribbed Newt <i>Pleurodeles waltl: </i>Evidence for the Presence of Dorsal Column and Lateral Cervical Nuclei

“…The NADPH-diaphorase (NADPHd) histochemical technique, known to stain specific neurons [Thomas and Pearse, 1964], can selectively stain particular populations of neurons in a Golgi-like manner [Scherer-Singler et al, 1983;Alonso et al, 1995;. Throughout the brain, NADPHd and NOS localizations are identical [Bredt and Snyder, 1992].…”

Distribution of Protein Gene Product 9.5-Immunopositive and NADPH-Diaphorase-Positive Neurons in the Common Marmoset (Callithrix jacchus) Accessory Olfactory Bulb

“…In the common marmoset AOB, the distribution of granule cells also remained unclear [19]. Since it has been documented that NADPH-diaphorase is localized in the granule cells in various animals [1,3,10,15,16], we conjectured that NADPH-diaphorase staining could reveal the distribution of the granule cells in the common marmoset AOB. In the present study, we observed that the granule cells were distributed under the MTL.…”

“…These histochemical markers are immunostaining for protein gene product (PGP) 9.5, which is predominantly localized in the mitral/ tufted cells in the rodent [14,22] and dogs [15], and staining for NADPH-diaphorase, which is predominantly localized in the granule cells in various animals [1,3,10,15,16].…”