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Abnormalities of Smell
Published in R James A England, Eamon Shamil, Rajeev Mathew, Manohar Bance, Pavol Surda, Jemy Jose, Omar Hilmi, Adam J Donne, Scott-Brown's Essential Otorhinolaryngology, 2022
Richard L. Doty, Steven M. Bromley
The most effective treatments available are those for conductive anosmia, where inflammation and other factors obstruct movement of molecules to olfactory receptors. Conductive and sensorineural olfactory loss are often distinguishable using a brief course of systemic steroid therapy since patients with conductive impairment often respond positively to the treatment, although long-term systemic steroid therapy is not advised. Increased topical efficacy can occur when the nasal drops or spray are administered in the head-down Moffett position. Proper allergy management is essential and may require the use of an antihistamine. When a bacterial infection is suspected (e.g. infectious sinusitis), a course of antibiotics should be used. Importantly, pre- and post-intervention olfactory testing should be performed to establish intervention efficacy, as well as to screen for subsequent slow relapse that is characteristic of most conductive disorders.
Chemosensation
Published in Emily Crews Splane, Neil E. Rowland, Anaya Mitra, Psychology of Eating, 2019
Emily Crews Splane, Neil E. Rowland, Anaya Mitra
The olfactory system is believed to use a combinatorial code to represent odor entities: Any given olfactory receptor is activated by a more or less restricted range of ligands and any given ligand activates several GPCR types (Malnic et al., 1999). Each olfaction-specific GPCR is located in the dendritic membrane of olfactory receptor neurons in the nasal epithelium. Each olfactory neuron expresses just one type of receptor. Each pure chemically defined odorant will give rise to a unique pattern of stimulation of the entire olfactory receptor population.
Identifying Pharmaceutical-Grade Essential Oils and Using Them Safely and Effectively in Integrative Medicine
Published in Aruna Bakhru, Nutrition and Integrative Medicine, 2018
Essential oils are unique remedies because they simultaneously influence psychological, biological, and cognitive health. The sense of smell—10,000 times more powerful than the sense of taste—is the only of the major senses that is directly connected to the brain (through the olfactory bulb). Airborne odor molecules enter the nostrils and dissolve in the nasal mucosa. Under the nasal mucosa, olfactory receptor neurons detect the odor molecules and transmit information to the olfactory bulb at the back of the nasal cavity. Sensory receptors of the olfactory bulb are part of the brain and send messages to the most primitive brain centers (limbic system structures) and the neo-cortex, which influence memory, emotions, and conscious thought. Therefore, the administration of essential oils produces a complete psychophysiological response that causes automatic adaptations by the central nervous system.
Discovery and design of G protein-coupled receptor targeting antibodies
Published in Expert Opinion on Drug Discovery, 2023
Sean M. Peterson, Catherine J. Hutchings, Cameron F. Hu, Melina Mathur, Janelle W. Salameh, Fumiko Axelrod, Aaron K. Sato
The human genome contains over 800 GPCRs, of which almost 400 are olfactory receptors. While olfactory receptor expression is mostly limited to the olfactory epithelium, some olfactory receptors are expressed in other tissues and targeting them may have therapeutic benefit [1]. GPCRs are classified according to their sequence homology and phylogenetic analysis of their evolution [2]. The Class A or rhodopsin-like family contains all of the olfactory receptors and many of the clinically targeted receptors including chemokine, amine, and peptide receptors. Class B1 receptors share a large extracellular N-terminus (Figure 1) and Class B2 belong to the adhesion GPCR family. Adhesion GPCRs are particularly intriguing antibody targets because of their unique extended extracellular domains [3]. Class C GPCRs are thought to function as dimers, as are the Class T, taste receptors. Finally, the Class F receptors contain Frizzled and Smoothened, two important GPCRs that regulate organismal development.
High prevalence of olfactory dysfunction detected in treatment-naive patients with head and neck cancer
Published in Acta Oto-Laryngologica, 2023
José Lucas Barbosa da Silva, Lucas Kanieski Anzolin, Samuel Pissinati Nicacio, Richard L. Doty, Fábio de Rezende Pinna, Richard Louis Voegels, Marco Aurélio Fornazieri
Several factors may cause or underlie the influences of HNC on the olfactory system. One basis of the olfactory loss of cancer patients, in general, could be related to significant weight loss. Such loss was present in 12.9% of our HNC patients. However, despite evidence that olfactory impairment can be associated with the weight loss of anorexic patients, such an association is not always found [18]. In one study of such psychiatric patients, UPSIT scores were equivalent to those of non-anorexic healthy individuals [9]. Since 74% of our HNC patient sample had olfactory but not weight loss. If weight loss is involved, its impact is likely limited. A more cogent hypothesis is that cancers themselves can produce substances that influence olfactory transduction and are potentially toxic to smell system elements. Among such agents are volatile organic compounds (polyamines) that have been identified by sniffer dogs, mice, and, in some cases, ‘electronic noses’ [10,19,20]. These molecules may act as antagonists to some volatile molecules at the level of the olfactory receptors, damage such receptors, and interact with transduction mechanisms throughout the olfactory system pathway.
Analyses on the influence of normal nasal morphological variations on odorant transport to the olfactory cleft
Published in Inhalation Toxicology, 2022
Ryan M. Sicard, Reanna Shah, Dennis O. Frank-Ito
Olfaction is the sensation arising from the nasal cavity following stimulation of the olfactory receptors by odorant molecules. Olfactory dysfunction is characterized by reduced or absent sense of smell, ranging from hyposmia to anosmia (Guss et al. 2009). While olfactory perception is effective when the combination of sensorineural components and conductive factors function properly, the role of conductive factors (respiratory effort and nasal anatomical structure) in olfaction has been given less attention. The nasal cavity plays an essential role in odor perception, which consists of the transportation of volatile chemical molecules via airflow to the olfactory receptors (Zhao et al. 2004). In order to completely understand human olfaction, it is crucial to gain knowledge of the airflow patterns in the human nasal cavity and quantify the transport of odorant-laden air to the olfactory region.