DFG 468981129 - Olfactory training

Understanding the receptor code for key aroma compounds is essential for understanding the mechanisms of food-related specific anosmia. This can enable the prediction of the frequency of occurrence of as yet unknown specific anosmias, e.g. via the population frequency of non-functional odor receptor gene variants, and contribute to the understanding of the molecular mechanisms of known specific anosmias. The knowledge gained from this project will be used to optimize the composition of sensory panels and may, in the long term, enable flexible food production that takes into account the needs and abilities of consumer groups and individuals, recognizing that the hedonic evaluation of food enabled by chemosensory testing is still the main factor influencing consumer decisions. Knowledge gained about the molecular mechanisms of smell training will be used to identify treatment approaches for patients with post-infectious anosmia. We propose the following hypotheses: (i) Identifying odor receptors for key food-related aroma compounds with known anosmia will make it possible to decode the receptor code of a specific anosmia in such a way that a single, specific receptor, or the most sensitive receptors activated in vitro by the same odor compound, determine an anosmic phenotype in vivo. This will validate the biological relevance of functional odorant-receptor pairings.(ii) The perception of individual odorants by individuals with specific and post-infectious, general anosmia can be improved through smell training. (iii) The smell perception improved through training is accompanied by increased gene expression of those receptors that are activated by the respective odorant under investigation.The proposed project combines the expertise of two working groups: infrastructure and experience with comprehensive receptor screening and agonist assignment, functional genomics, molecular genetics, and gene expression analysis (Krautwurst group) as well as access to large patient/subject cohorts, and infrastructure and experience with detailed sensory studies and biopsies (Hummel group).The specific objectives are: 1. Identification of anosmic individuals, their chemosensory examination, and brush biopsies before and after smell training with anosmia-related odorants. 2. Elucidation of the receptor code of specific anosmias. 3. Genotyping of individuals with regard to the odor receptors involved in anosmias. 4. Quantification of receptor-specific transcription levels in normosmic individuals and patients with specific and post-infectious, general anosmia, before and after smell training with anosmia-related odors.

DFG