Essay Sample on The Vomeronasal Organ

The vomeronasal organ is a chemoreceptor organ that is local in the nasal cavity at the base, in the appearance of a paired tubular structure. This organ is common in most reptiles, amphibians, and nonprimate mammals, while absent in birds and apes. The crescent-shaped side contains receptor neurons that are filled with fluid emanating from glands on the concave side of the crescent shape lumen. At the lumen are blood vessels and sinuses connected with the nervous system and are responsible for vasodilation and vasoconstriction to create a pump stimulus that enables access to the lumen. Substances like noradrenaline (NA) found in traces of VNO have been known to alter the concentration of epithelial Na+ and reduce the amounts of Ca2+.

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VNO Sensory Epithelium

The sensory epithelium of the VNO consists of supporting cells, receptor cells, and basal cells. These cells usually remain constant during the first two months of birth and begin to increase steadily until puberty. The axons of the receptor neurons merge to form a thicker layer, which is the vomeronasal nerves. Vomeronasal sensory neurons have a functional relationship with the mediobasal hypothalamus in every adult mammal. This influences the behavior and functioning of the neuroendocrine. The subdivisions on vomeronasal have been spotted in several mammals using a wide variety of techniques.

VNO Transduction by Pheromones

The signaling mechanism, which is in the VNO, is a bit different from those of the olfactory sensory neurons. Specifically, there is an increased production of IP3 in the VNO, which is stimulated by the pheromones. The secretions are traced in vaginal discharge, which is responsible for attraction to the male, responsible for mounting behavior. In animals like snakes, the adenylate cyclase increases the sensitivity of the VNO through Ca2+. In rats, experiments have utilized the spraying of male urine on the female rate, which stimulated the VNO through the G-protein.

Physiology of VNO Sensory Neurons

The vomeronasal neurons and their sensitivity are responsible for firing action potentials. This is measured in terms of the injections done as 1 p A. An increased injection of p A increases the number of the firing of action potentials (Keverne, 2019). This indicates a linear relationship between the p A and the number of firings of action potentials. Other interventions that can be used include the use of persistent stimuli, which is even more useful for prolonged exposure to pheromones. This induces changes in the reproduction of mice. Most of the VNO neurons respond to chemical stimulation and record a negative holding potential on the outward current. The subdivisions of AOB, which include V1Rs and V2Rs, have an alternate response to the VNO. The activation of neurons containing the V1Rs produces oscillations that are provoked by electrical simulations of axions—the activity releases excited, which travels in both anterior and posteriors directions.

VNO Projections Behavior

Unlike the olfactory system, the VNO has relatively smaller families of receptor genes. This, however, can obtain coding for individual mouse recognition, which occurs in the VNO relay located in AOB. To achieve the attention, there is a need for amplification of differences in the spatial and temporal activity in the AOB. The small receptor has an effect in which it produces different compositions in the pheromone and thus can be thus recognized.

References

Keverne, E. B. (2019). The vomeronasal organ. Science, 286(5440), 716-720.