Decreasing prevalence of specific anosmia to non-steroid odorants from childhood to adolescence

Specific anosmia is defined as the inability to detect a particular odorant, despite a normal olfactory function. Previous studies reported sex-related difference in detection threshold to steroid odorants, like androstenone or androstadienone during adolescence, and boys showed an increased detection threshold with age. However, such investigations have not been performed for non-steroid odorants. Hence, the current study investigated sex-and age-related effects on the prevalence of specific anosmia in children/adolescents aged 5-14 years (n = 800) to non-steroid odorants. The detection thresholds of three non-steroid odorants (bacdanol, methylsalicylate, and 3-hydrox-2-methyl-4-pyrone) with different molecular weights were measured. Results indicate that the rate of specific anosmia for all three odorants decreases from childhood to adolescence. This decrease is independent of sex and is most pronounced for odorants with higher molecular weight compared to the odorant with lower molecular weight. Thus, the development of basic olfactory functions for these three odorants continues until adolescence. The effect of molecular weight suggests that the locus of effect is at the periphery of the olfactory system, due to changes in either olfactory receptor expression patterns or perireceptor events.