The Presence of the Human Vomeronasal Organ (VNO) and Its Function

Presence of human vomeronasal (VNO) and its function Vomeronasal (VNO), also known as Jacobson's organ, is an auxiliary olfactory organ seen in many animals. It is also the first phase of sensory organs involved in its assisted olfactory system and Flehman reaction. In many mammalian species, parts of the olfactory epithelium are separately packaged in VNO [1]. Animals use their VNO to contact chemosensory cues such as pheromones released from others.

In some animals, the vomeronasal (VNO) is part of the second completely independent olfaction called the auxiliary olfactory system. Many studies have been conducted to investigate whether VNO actually exists in adults. Trotier et al. Approximately 92% of subjects without diaphragmatic surgery are estimated to have at least one complete VNO. Meanwhile, Kjaer and Fisher Hansen said that as with some primates, the structure of VNO disappeared during fetal development. However, Smith and Bhatnagar (2000) argues that Kjaer and Fisher Hansen missed the structure of the elderly fetus. Won (2000) found evidence of VNO in 29 (59.1%) of the 22 dead bodies and 28 active patients (28.2%) out of 28. In light of these findings, some scientists believe that VNO exists in adults. However, most researchers have tried to determine the opening of the human vomeronasal organ, rather than to identify the renal tubular epithelial structure itself.

The vomeronasis (VNO) is an organ of smell seen in animals and humans. Organs are on the septum or mouth and are used to detect pheromones. Pheromone is a chemical substance released from animals to the surroundings and affecting the behavior of other surrounding animals. Unlike animals, humans can communicate with languages ​​without relying on chemical signals, so it has long been debated whether humans actually use their own VNO to detect pheromones. Research has shown that genes encoding human VNO receptors do not function. In other words, such organs are not used at all.

Non-human mammals and non-mammalian species such as reptiles and amphibians show specific tissues capable of detecting most pheromones: the vomeronasal organ (VNO) located in the head (anterior) nasal cavity. VNO contains bipolar receptor cells that pass through the nasal septum and pass through the mesh plate and have axonal neurites that are adjacent to the main olfactory bulb, but are not yet ligated (Figure 2). Human fetuses exhibit VNO with typical bipolar cells and axonal processes, but most evidence suggests that it is functionally inactivated postnatally. The gene encoding the receptor protein is a pseudogenesis without protein expression; bipolar receptor cells are no longer detectable and secondary olfactory bulbs are absent. Interestingly, GnRH neurons, the key of pubertal development and reproduction, displace degenerative VNO nerves as they move from the fetal VNO region to the forebrain base (Wysocki and Preti, 2004)