Related Experiment Video
Updated: Jul 3, 2026

Real-time In Vitro Monitoring of Odorant Receptor Activation by an Odorant in the Vapor Phase
Published on: April 23, 2019
The effect of hormone therapy on olfactory sensitivity is dependent on apolipoprotein E genotype
Erin E Sundermann1, Paul E Gilbert, Claire Murphy
1Department of Psychology, San Diego State University, USA.
Abstract:
Patients with Alzheimer's disease (AD) show a deficit in olfactory threshold sensitivity. The Apolipoprotein E (ApoE) epsilon4 allele is associated with increased risk of AD and earlier symptom onset. Hormone therapy (HT) may exert neuroprotective effects on brain areas affected by AD. The current study investigated the effect of HT on performance on an olfactory threshold test in epsilon4 positive and epsilon4 negative non-hysterectomized, non-demented, elderly females and AD patients. Among the non-demented participants, epsilon4 positive females who had received HT performed 1) significantly better than those without HT, and 2) at levels similar to those of epsilon4 negative females. In contrast, those without HT who were epsilon4 positive performed significantly worse than those who were epsilon4 negative. HT had no effect on performance in AD patients regardless of epsilon4 status. These results suggest that HT may offer protection against loss of olfactory function in epsilon4 positive individuals in preclinical stages of AD. Future research is warranted in order to investigate further the neuroprotective role of HT on sensory and cognitive functions in non-demented aging individuals.
Related Concept Videos
Pharmacogenetics of Drug Targets: β₂-Adrenergic Receptors, Apo E, Thymidylate Synthase
Olfactory Receptors: Location and Structure
Target Cell Response to Hormones
Notably, the cellular response can be regulated by altering the number of receptors expressed in the cell. For example, prolonged exposure to elevated hormone levels results in a gradual decline or down-regulation in the number of receptors for that specific hormone on the cell surface. Conversely, in response to low hormone levels, cells may use up-regulation, producing an...
Pharmacogenetic Phenotypes: Alterations in Pharmacokinetics, Drug Targets and Biologic Milieu
Olfaction
The olfactory receptors are embedded in the cilia of the...
Physiology of Smell and Olfactory Pathway
The olfactory...

