scholarly journals Congenital Agenesis of the Olfactory Bulbs: What to Suspect?

Cureus ◽  
2021 ◽  
Author(s):  
Isabel Costa ◽  
Berta Rodrigues ◽  
Luís Dias
Author(s):  
James E. Crandall ◽  
Linda C. Hassinger ◽  
Gerald A. Schwarting

Cell surface glycoconjugates are considered to play important roles in cell-cell interactions in the developing central nervous system. We have previously described a group of monoclonal antibodies that recognize defined carbohydrate epitopes and reveal unique temporal and spatial patterns of immunoreactivity in the developing main and accessory olfactory systems in rats. Antibody CC2 reacts with complex α-galactosyl and α-fucosyl glycoproteins and glycolipids. Antibody CC1 reacts with terminal N-acetyl galactosamine residues of globoside-like glycolipids. Antibody 1B2 reacts with β-galactosyl glycolipids and glycoproteins. Our light microscopic data suggest that these antigens may be located on the surfaces of axons of the vomeronasal and olfactory nerves as well as on some of their target neurons in the main and accessory olfactory bulbs.


2021 ◽  
pp. 1-12
Author(s):  
Georg F. Striedter ◽  
R. Glenn Northcutt

Comparative neurobiologists have long wondered when and how the dorsal pallium (e.g., mammalian neocortex) evolved. For the last 50 years, the most widely accepted answer has been that this structure was already present in the earliest vertebrates and, therefore, homologous between the major vertebrate lineages. One challenge for this hypothesis is that the olfactory bulbs project throughout most of the pallium in the most basal vertebrate lineages (notably lampreys, hagfishes, and lungfishes) but do not project to the putative dorsal pallia in teleosts, cartilaginous fishes, and amniotes (i.e., reptiles, birds, and mammals). To make sense of these data, one may hypothesize that a dorsal pallium existed in the earliest vertebrates and received extensive olfactory input, which was subsequently lost in several lineages. However, the dorsal pallium is notoriously difficult to delineate in many vertebrates, and its homology between the various lineages is often based on little more than its topology. Therefore, we suspect that dorsal pallia evolved independently in teleosts, cartilaginous fishes, and amniotes. We further hypothesize that the emergence of these dorsal pallia was accompanied by the phylogenetic restriction of olfactory projections to the pallium and the expansion of inputs from other sensory modalities. We do not deny that the earliest vertebrates may have possessed nonolfactory sensory inputs to some parts of the pallium, but such projections alone do not define a dorsal pallium.


1976 ◽  
Vol 26 (6) ◽  
pp. 1087-1091 ◽  
Author(s):  
E. Chung-Hwang ◽  
H. Khurana ◽  
H. Fisher
Keyword(s):  

2020 ◽  
Vol 45 (7) ◽  
pp. 523-531
Author(s):  
Sara Touj ◽  
Samie Cloutier ◽  
Amel Jemâa ◽  
Mathieu Piché ◽  
Gilles Bronchti ◽  
...  

Abstract It is well established that early blindness results in enhancement of the remaining nonvisual sensory modalities accompanied by functional and anatomical brain plasticity. While auditory and tactile functions have been largely investigated, the results regarding olfactory functions remained less explored and less consistent. In the present study, we investigated olfactory function in blind mice using 3 tests: the buried food test, the olfactory threshold test, and the olfactory performance test. The results indicated better performance of blind mice in the buried food test and odor performance test while there was no difference in the olfactory threshold test. Using histological measurements, we also investigated if there was anatomical plasticity in the olfactory bulbs (OB), the most salient site for olfactory processing. The results indicated a larger volume of the OB driven by larger glomerular and granular layers in blind mice compared with sighted mice. Structural plasticity in the OB may underlie the enhanced olfactory performance in blind mice.


2008 ◽  
Vol 276 (1657) ◽  
pp. 667-673 ◽  
Author(s):  
Darla K Zelenitsky ◽  
François Therrien ◽  
Yoshitsugu Kobayashi

This research presents the first quantitative evaluation of the olfactory acuity in extinct theropod dinosaurs. Olfactory ratios (i.e. the ratio of the greatest diameter of the olfactory bulb to the greatest diameter of the cerebral hemisphere) are analysed in order to infer the olfactory acuity and behavioural traits in theropods, as well as to identify phylogenetic trends in olfaction within Theropoda. A phylogenetically corrected regression of olfactory ratio to body mass reveals that, relative to predicted values, the olfactory bulbs of (i) tyrannosaurids and dromaeosaurids are significantly larger, (ii) ornithomimosaurs and oviraptorids are significantly smaller, and (iii) ceratosaurians, allosauroids, basal tyrannosauroids, troodontids and basal birds are within the 95% CI. Relative to other theropods, olfactory acuity was high in tyrannosaurids and dromaeosaurids and therefore olfaction would have played an important role in their ecology, possibly for activities in low-light conditions, locating food, or for navigation within large home ranges. Olfactory acuity was the lowest in ornithomimosaurs and oviraptorids, suggesting a reduced reliance on olfaction and perhaps an omnivorous diet in these theropods. Phylogenetic trends in olfaction among theropods reveal that olfactory acuity did not decrease in the ancestry of birds, as troodontids, dromaeosaurids and primitive birds possessed typical or high olfactory acuity. Thus, the sense of smell must have remained important in primitive birds and its presumed decrease associated with the increased importance of sight did not occur until later among more derived birds.


2017 ◽  
Vol 23 (5) ◽  
pp. 772-778 ◽  
Author(s):  
Bruna R. S. M. Oliveira ◽  
Flavia V. Vieira ◽  
Dielson de S. Vieira ◽  
Sergio E. L. da Silva ◽  
Roberto Gameiro ◽  
...  

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