scholarly journals Does a third intermediate model for the vomeronasal processing of information exist? Insights from the macropodid neuroanatomy

2021 ◽  
Author(s):  
Mateo V. Torres ◽  
Irene Ortiz-Leal ◽  
Paula R. Villamayor ◽  
Andrea Ferreiro ◽  
José Luis Rois ◽  
...  
Keyword(s):  
Vomeronasal Organ ◽  
Tammar Wallaby ◽  
Vomeronasal System ◽  
Mammal Species ◽  
Α Subunit ◽  
Intermediate Model ◽  
Ulex Europaeus ◽  
Vomeronasal Receptors ◽  
Segregated Model ◽  
Degree Of Differentiation

AbstractThe study of the α-subunit of Gi2 and Go proteins in the accessory olfactory bulb (AOB) was crucial for the identification of the two main families of vomeronasal receptors, V1R and V2R. Both families are expressed in the rodent and lagomorph AOBs, according to a segregated model characterized by topographical anteroposterior zonation. Many mammal species have suffered from the deterioration of the Gαo pathway and are categorized as belonging to the uniform model. This scenario has been complicated by characterization of the AOB in the tammar wallaby, Notamacropus eugenii, which appears to follow a third model of vomeronasal organization featuring exclusive Gαo protein expression, referred to as the intermediate model, which has not yet been replicated in any other species. Our morphofunctional study of the vomeronasal system (VNS) in Bennett’s wallaby, Notamacropus rufogriseus, provides further information regarding this third model of vomeronasal transduction. A comprehensive histological, lectin, and immunohistochemical study of the Bennett’s wallaby VNS was performed. Anti-Gαo and anti-Gαi2 antibodies were particularly useful because they labeled the transduction cascade of V2R and V1R receptors, respectively. Both G proteins showed canonical immunohistochemical labeling in the vomeronasal organ and the AOB, consistent with the anterior–posterior zonation of the segregated model. The lectin Ulex europaeus agglutinin selectively labeled the anterior AOB, providing additional evidence for the segregation of vomeronasal information in the wallaby. Overall, the VNS of the Bennett’s wallaby shows a degree of differentiation and histochemical and neurochemical diversity comparable to species with greater VNS development. The existence of the third intermediate type in vomeronasal information processing reported in Notamacropus eugenii is not supported by our lectin-histochemical and immunohistochemical findings in Notamacropus rufogriseus.

scholarly journals Does a Third Model for the Vomeronasal Processing of Information Exist? Insights from the Macropodid Neuroanatomy

2021 ◽  
Author(s):  
Mateo V. TORRES ◽  
Irene ORTIZ-LEAL ◽  
Paula R. VILLAMAYOR ◽  
Andrea FERREIRO ◽  
José Luis ROIS ◽  
...  
Keyword(s):  
Vomeronasal Organ ◽  
Tammar Wallaby ◽  
Vomeronasal System ◽  
Mammal Species ◽  
Α Subunit ◽  
Ulex Europaeus ◽  
Vomeronasal Receptors ◽  
Uniform Model ◽  
Segregated Model ◽  
Degree Of Differentiation

Abstract The study of the α-subunit of Gi2 and Go proteins in the accessory olfactory bulb (AOB) was crucial for the identification of the two main families of vomeronasal receptors, V1R and V2R. Both families are expressed in the rodent and lagomorph AOBs, according to a segregated model characterized by topographical anteroposterior zonation. Many mammal species have suffered from the deterioration of the Gαo pathway and are categorized as belonging to the uniform model. This scenario has been complicated by characterization of the AOB in the tammar wallaby, Macropus eugenii, which appears to follow a third model of vomeronasal organization featuring exclusive Gαo protein expression, referred to as the intermediate model, which has not yet been replicated in any other species. Our morphofunctional study of the vomeronasal system (VNS) in Bennett’s wallaby, Macropus rufogriseus, provides further information regarding this third model of vomeronasal transduction.A comprehensive histological, lectin, and immunohistochemical study of the Bennett’s wallaby VNS was performed. Anti-Gαo and anti-Gαi2 antibodies were particularly useful because they labeled the transduction cascade of V2R and V1R receptors, respectively. Both G proteins showed canonical immunohistochemical labeling in the vomeronasal organ and the AOB, consistent with the anterior-posterior zonation of the segregated model. The lectin Ulex europaeus agglutinin selectively labeled the anterior AOB, providing additional evidence for the segregation of vomeronasal information in the wallaby.Overall, the VNS of the Bennett’s wallaby shows a degree of differentiation and histochemical and neurochemical diversity comparable to species with greater VNS development, which does not support the existence of a third “intermediate” type of vomeronasal information processing.

scholarly journals Central role of G protein Gαi2 and Gαi2+ vomeronasal neurons in balancing territorial and infant-directed aggression of male mice

2019 ◽  
Vol 116 (11) ◽  
pp. 5135-5143 ◽  
Author(s):  
Anne-Charlotte Trouillet ◽  
Matthieu Keller ◽  
Jan Weiss ◽  
Trese Leinders-Zufall ◽  
Lutz Birnbaumer ◽  
...  
Keyword(s):  
G Protein ◽  
Sensory Neurons ◽  
Neural Activity ◽  
Parental Behavior ◽  
Vomeronasal Organ ◽  
Male Infant ◽  
Lateral Septum ◽  
Male Mice ◽  
Protein Subunit ◽  
Α Subunit

Aggression is controlled by the olfactory system in many animal species. In male mice, territorial and infant-directed aggression are tightly regulated by the vomeronasal organ (VNO), but how diverse subsets of sensory neurons convey pheromonal information to limbic centers is not yet known. Here, we employ genetic strategies to show that mouse vomeronasal sensory neurons expressing the G protein subunit Gαi2 regulate male–male and infant-directed aggression through distinct circuit mechanisms. Conditional ablation of Gαi2 enhances male–male aggression and increases neural activity in the medial amygdala (MeA), bed nucleus of the stria terminalis, and lateral septum. By contrast, conditional Gαi2 ablation causes reduced infant-directed aggression and decreased activity in MeA neurons during male–infant interactions. Strikingly, these mice also display enhanced parental behavior and elevated neural activity in the medial preoptic area, whereas sexual behavior remains normal. These results identify Gαi2 as the primary G protein α-subunit mediating the detection of volatile chemosignals in the apical layer of the VNO, and they show that Gαi2+ VSNs and the brain circuits activated by these neurons play a central role in orchestrating and balancing territorial and infant-directed aggression of male mice through bidirectional activation and inhibition of different targets in the limbic system.

scholarly journals Sensitivity and transduction mechanisms of responses to general odorants in turtle vomeronasal system.

1991 ◽  
Vol 98 (5) ◽  
pp. 909-919 ◽  
Author(s):  
T Shoji ◽  
K Kurihara
Keyword(s):  
Vomeronasal Organ ◽  
Na Channel ◽  
Channel Blockers ◽  
Ca Channel ◽  
Essential Difference ◽  
Free Solution ◽  
Vomeronasal System ◽  
Nacl Solution ◽  
Response Curves ◽  
Transduction Mechanisms

(a) The responses of the vomeronasal organ to general odorants in the turtle, Geoclemys reevesii, were measured by recording the accessory olfactory bulbar responses. The threshold concentrations of the vomeronasal responses to various odorants were similar to those in main olfactory bulbar responses, indicating that vomeronasal cells lacking cilia and olfactory cells having many cilia have similar sensitivities to general odorants. (b) The vomeronasal epithelium was perfused with 100 mM NaCl solution and the salt-free solution and the effects of NaCl on the vomeronasal responses to various odorants were examined. There was no essential difference between the concentration-response curves for n-amyl acetate and menthone dissolved in 100 mM NaCl solution and those dissolved in the salt-free solution in the whole concentration range examined. The ratios of the magnitudes of vomeronasal responses in the salt-free solution to those in 100 mM NaCl solution were between 1.01 and 1.10 for seven odorants tested. (c) The magnitudes of responses to the odorants were unchanged by changes in NaCl concentrations. The replacement of Na+ with organic cations such as choline+, Bis-Tris propane2+, and N-acetyl-D-glucosamine+ did not affect the magnitudes of the responses to the odorants. The Na channel blocker amiloride also did not affect the responses. (d) The vomeronasal responses were practically unchanged by changes in CaCl2 concentration. The Ca channel blockers diltiazem and verapamil did not affect the responses. (e) The replacement of Cl- with SO4(2-) did not affect the magnitudes of the vomeronasal responses. (f) The present results suggest that ion transport across the apical membranes of vomeronasal receptor cells does not contribute to the responses to odorants in the turtle.

scholarly journals Goα Expression in the Vomeronasal Organ and Olfactory Bulb of the Tammar Wallaby

2012 ◽  
Vol 37 (6) ◽  
pp. 567-577 ◽  
Author(s):  
Nanette Y. Schneider ◽  
Terrence P. Fletcher ◽  
Geoff Shaw ◽  
Marilyn B. Renfree
Keyword(s):  
Olfactory Bulb ◽  
Vomeronasal Organ ◽  
Tammar Wallaby

The Harderian gland of two species of snakes: Pseudonaja textilis (Elapidae) and Thamnophis sirtalis (Colubridae)

2003 ◽  
Vol 81 (3) ◽  
pp. 357-363 ◽  
Author(s):  
Susan J Rehorek ◽  
Mimi Halpern ◽  
Bruce T Firth ◽  
Mark N Hutchinson
Keyword(s):  
Gross Anatomy ◽  
Vomeronasal Organ ◽  
Harderian Gland ◽  
Interspecific Variation ◽  
Nasolacrimal Duct ◽  
Thamnophis Sirtalis ◽  
Mucous Cells ◽  
Vomeronasal System ◽  
Snake Species ◽  
Harderian Glands

The reptilian Harderian gland is a poorly understood cephalic structure. Despite the recent assertion that in snakes it may function as part of the vomeronasal system, the Harderian gland has been described in few snake species. In this study we examined the gross anatomy, histology, and ultrastructure of the Harderian gland of two different advanced snake species (Colubroidea): Pseudonaja textilis (Elapidae) and Thamnophis sirtalis (Colubridae). In both species the Harderian gland is a large serous gland whose secretions pass directly into the vomeronasal organ via the nasolacrimal duct. Contrary to previous publications, the Harderian gland in both species studied possesses a specific duct system lined by mucous cells. However, the Harderian glands of these two species differ in shape, the histochemical nature of these mucous secretions, and the ultrastructure of the serous granules. In conclusion, though the Harderian glands of snakes are remarkably conserved morphologically, there is some interspecific variation.

scholarly journals Presence of the vomeronasal system in aquatic salamanders

2000 ◽  
Vol 355 (1401) ◽  
pp. 1209-1213 ◽  
Author(s):  
Heather L. Eisthen
Keyword(s):  
Electron Microscopy ◽  
Common Ancestor ◽  
Vomeronasal Organ ◽  
Last Common Ancestor ◽  
Vomeronasal System ◽  
Necturus Maculosus ◽  
Transmission Electron ◽  
Terrestrial Life ◽  
Olfactory Systems ◽  
Aquatic Salamanders

Previous reports have indicated that members of the proteid family of salamanders lack a vomeronasal system, and this absence has been interpreted as representing the ancestral condition for aquatic amphibians. I examined the anatomy of the nasal cavities, nasal epithelia, and forebrains of members of the proteid family, mudpuppies ( Necturus maculosus ), as well as members of the amphiumid and sirenid families ( Amphiuma tridactylum and Siren intermedia ). Using a combination of light and transmission electron microscopy, I found no evidence that mudpuppies possess a vomeronasal system, but found that amphiuma and sirens possess both vomeronasal and olfactory systems. Amphiumids and sirenids are considered to be outgroups relative to proteids; therefore, these data indicate that the vomeronasal system is generally present in salamanders and has been lost in mudpuppies. Given that the vomeronasal system is generally present in aquatic amphibians, and that the last common ancestor of amphibians and amniotes is believed to have been fully aquatic, I conclude that the vomeronasal system arose in aquatic tetrapods and did not originate as an adaptation to terrestrial life. This conclusion has important implications for the hypothesis that the vomeronasal organ is specialized for detection of non–volatile compounds.

Passage of Harderian gland secretions to the vomeronasal organ of Thamnophis sirtalis (Serpentes: Colubridae)

2000 ◽  
Vol 78 (7) ◽  
pp. 1284-1288 ◽  
Author(s):  
S J Rehorek ◽  
W J Hillenius ◽  
W Quan ◽  
M Halpern
Keyword(s):  
Vomeronasal Organ ◽  
Harderian Gland ◽  
Nasolacrimal Duct ◽  
Sensory Epithelium ◽  
Thamnophis Sirtalis ◽  
Vomeronasal System ◽  
Treatment Groups ◽  
Terrestrial Vertebrates ◽  
Rich Solution ◽  
The Right

The Harderian gland is a poorly understood structure found in the anterior orbit of most terrestrial vertebrates. In colubrid snakes it is a seromucous gland with a large postorbital portion. Numerous functions have been ascribed to this gland, including contributions to orbital lubrication or the vomeronasal system. Anatomically the Harderian gland is connected to the vomeronasal organ (VNO) via the nasolacrimal duct. In this study we traced the serous secretions of the Harderian gland of two subspecies of Thamnophis sirtalis (Colubridae), using autoradiographic techniques at the light-microscopic level. We injected the Harderian gland of the snakes with H3-proline either unilaterally (right side) or bilaterally. The right Harderian glands of both treatment groups were then injected with a potassium-rich solution. No labeling was observed in the orbital space of any treatment group, suggesting that the Harderian gland secretions of T. sirtalis do not function in orbital lubrication. Labeling was only observed in the right Harderian gland, Harderian gland ducts, nasolacrimal duct, apical vomeronasal sensory epithelium, VNO lumen, and vomeronasal duct. No such labeling was observed in any of the other treatments examined. Thus, the serous secretions of the Harderian gland in snakes flow to the VNO, and may be considered part of the vomeronasal system. The specific function of the Harderian gland secretions in the vomeronasal system remains to be determined.

scholarly journals The vomeronasal organ of the tammar wallaby

2008 ◽  
Vol 213 (2) ◽  
pp. 93-105 ◽  
Author(s):  
Nanette Y. Schneider ◽  
Terence P. Fletcher ◽  
Geoff Shaw ◽  
Marilyn B. Renfree
Keyword(s):  
Vomeronasal Organ ◽  
Tammar Wallaby

scholarly journals Sequence Diversity and Genomic Organization of Vomeronasal Receptor Genes in the Mouse

2000 ◽  
Vol 10 (12) ◽  
pp. 1958-1967
Author(s):  
Karina Del Punta ◽  
Andrea Rothman ◽  
Ivan Rodriguez ◽  
Peter Mombaerts
Keyword(s):  
Genomic Organization ◽  
Vomeronasal Organ ◽  
Sequence Diversity ◽  
Sequence Information ◽  
Bacterial Artificial Chromosomes ◽  
Vomeronasal System ◽  
Coding Region ◽  
Artificial Chromosomes ◽  
Coding Regions ◽  
Vomeronasal Receptor

The vomeronasal system of mice is thought to be specialized in the detection of pheromones. Two multigene families have been identified that encode proteins with seven putative transmembrane domains and that are expressed selectively in subsets of neurons of the vomeronasal organ. The products of these vomeronasal receptor (Vr) genes are regarded as candidate pheromone receptors. Little is known about their genomic organization and sequence diversity, and only five sequences of mouse V1r coding regions are publicly available. Here, we have begun to characterize systematically the V1r repertoire in the mouse. We isolated 107 bacterial artificial chromosomes (BACs) containing V1r genes from a 129 mouse library. Hybridization experiments indicate that at least 107 V1r-like sequences reside on these BACs. We assembled most of the BACs into six contigs, of which one major contig and one minor contig were characterized in detail. The major contig is 630–860 kb long, encompasses a cluster of 21–48 V1r genes, and contains markerD6Mit227. Sequencing of the coding regions was facilitated by the absence of introns. We determined the sequence of the coding region of 25 possibly functional V1r genes and seven pseudogenes. The functional V1rs can be arranged into three groups; V1rs of one group are novel and substantially divergent from the other V1rs. The genomic and sequence information described here should be useful in defining the biological function of these receptors.

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