Olfaction scaffolds the developing human from neonate to adolescent and beyond

The impact of the olfactory sense is regularly apparent across development. The fetus is bathed in amniotic fluid (AF) that conveys the mother's chemical ecology. Transnatal olfactory continuity between the odours of AF and milk assists in the transition to nursing. At the same time, odours emanating from the mammary areas provoke appetitive responses in newborns. Odours experienced from the mother's diet during breastfeeding, and from practices such as pre-mastication, may assist in the dietary transition at weaning. In parallel, infants are attracted to and recognize their mother's odours; later, children are able to recognize other kin and peers based on their odours. Familiar odours, such as those of the mother, regulate the child's emotions, and scaffold perception and learning through non-olfactory senses. During juvenility and adolescence, individuals become more sensitive to some bodily odours, while the timing of adolescence itself has been speculated to draw from the chemical ecology of the family unit. Odours learnt early in life and within the family niche continue to influence preferences as mate choice becomes relevant. Olfaction thus appears significant in turning on, sustaining and, in cases when mother odour is altered, disturbing adaptive reciprocity between offspring and carer during the multiple transitions of development between birth and adolescence. This article is part of the Theo Murphy meeting issue 'Olfactory communication in humans'.

The Effect of Female Pheromone on the Functional State of Young Men

Introduction. Modern studies show that the presentation of smell of female mice before male mice infection with the influenza virus activates non-specific immune response which protects male mice from infection of the upper respiratory tract and reducing their mortality. However the researches have not studied the adaptive effect of female sexual pheromone on men.

The aim of this work was to study the effect of odor of synthetic analogue of natural female pheromone (Osmopherine) on the functional state of young men often suffering from acute respiratory infections (ARI) and allergic diseases.

Materials and methods. We studied four-week effect of Osmopherine on the psycho-emotional state, the concentration of hormones (testosterone, cortisol) and immunoglobulins (sIgA, total IgG), the percentage of leukocytes in the blood and the individual smell of young men, who have ARI more than 4 times a year or an allergic disease. The study involved 117 boys aged 19–23 years. Olfactory testing of individual odor samples of young men was carried out by young women (n = 32) aged 18–22 years.

Results. It was found that female pheromone has a positive effect on the functional state of men with different immune systems. However its effect is caused by the pathogenesis of the disease. Application of Osmopherine in men with reduced immunity causes an increased activity, improved mood, reduced anxiety and stabilized testosterone level. Men with allergic diseases did not have the same effect. A significant 2 times decrease in the content of eosinophils was found, which indirectly indicates the decrease in the activity of the delayed phase of allergic reactions of immediate type.

Conclusion. The immune system functions according to its internal laws and programs. However its activity for the benefit of the whole body is integrated and regulated by the nervous and endocrine systems. Therefore modulating effect on the functioning of the immune system can be mediated through the presentation of pheromones.

[The role of the vomeronasal system in the formation of the human sexual behaviour]

This review deals with the structure and function of the vomeronasal system and evaluation of its influence on the sexual sphere of humans and animals. Special attention is given to the role of pheromones in the regulation of the sexual behaviour. The data concerning the function of the vomeronasal organ following surgical interventions in the nasal cavity are discussed.