Related Experiment Video
Updated: Aug 20, 2025
06:34
An Olfactory Preference Test for Measuring Olfactory Hedonic Biases in Mouse Models of Depression
Published on: July 11, 2025
188
Physiological discrimination and correlation between olfactory and gustatory dysfunction in long-term COVID-19.
1Neuroscience, Imaging and Clinical Sciences Department, 'G. d'Annunzio' Chieti-Pescara University, Chieti, Italy.
Physiological Reports
|November 22, 2022
Summary
Long COVID can cause lasting smell and taste dysfunction. A year-long study using an electronic nose found varied sensory loss patterns and correlations, suggesting neuroinvasion impacts chemical senses.
Area of Science:
- Neuroscience
- Otorhinolaryngology
- Infectious Diseases
Background:
- COVID-19, caused by SARS-CoV-2, presents with taste and smell dysfunction, but underlying mechanisms and long-term effects require further understanding.
- Differentiating between taste and smell impairments is crucial for accurate diagnosis and management of post-viral sensory deficits.
Observation:
- A longitudinal study re-evaluated long-term COVID-19 patients with anosmia (loss of smell) and ageusia (loss of taste) after one year.
- A volatilomic approach utilizing an electronic nose, coupled with olfactometric and gustometric tests, assessed a spectrum of sensory dysfunctions.
- Observed patterns included normal senses to complete loss, with specific correlations noted between olfactory threshold and olfactory perception.
Findings:
- A strong correlation exists between olfactory threshold and olfactory uni- and cross-modal perception.
- A moderate correlation was found between olfactory and taste thresholds.
- No significant correlation was identified between olfactory threshold and taste threshold, highlighting distinct sensory pathways.
Implications:
- Testing chemical senses can objectively differentiate between taste and olfactory impairments in post-COVID-19 patients.
- The findings support the hypothesis of long-term viral neuroinvasion, likely via the olfactory system, potentially damaging related multisensory areas affecting taste and smell.
More Related Videos
Related Concept Videos
01:03Olfactory Receptors: Location and Structure
9.4K
The process of olfaction, also known as the sense of smell, is a sophisticated chemical response system. The specialized sensory neurons that facilitate this process, known as olfactory receptor neurons, are situated in an upper segment of the nasal cavity, known as the olfactory epithelium. Olfactory sensory neurons are bipolar, with their dendrites extending from the epithelium's apex into the mucus that lines the nasal cavity. Airborne molecules, when inhaled, traverse the olfactory...
9.4K
01:20Taste Buds and Receptors
2.4K
Gustation, or the sense of taste, is intrinsically linked to the anatomical structures located on the tongue. This organ's surface, along with the entirety of the oral cavity, is adorned with stratified squamous epithelium. Evident on the tongue are elevated structures known as papillae (singular = papilla), which house the mechanisms for the transduction of gustatory stimuli. Four distinct types of papillae exist, each identified by their unique morphological attributes: the circumvallate,...
2.4K
01:20Physiology of Smell and Olfactory Pathway
9.1K
Humans detect odors with the help of specialized cells located in the upper part of the nasal cavity, called olfactory receptor neurons (ORNs). ORNs possess hair-like structures called cilia, which are receptive to sensations from the inhaled air. When an odorant molecule binds to a specific receptor on the cell of the cilia, it leads to a series of events that ultimately cause the ORN to send electrical signals to the olfactory bulb in the brain through the olfactory nerves.
The olfactory...
The olfactory...
9.1K
01:25Olfaction
44.8K
The sense of smell is achieved through the activities of the olfactory system. It starts when an airborne odorant enters the nasal cavity and reaches olfactory epithelium (OE). The OE is protected by a thin layer of mucus, which also serves the purpose of dissolving more complex compounds into simpler chemical odorants. The size of the OE and the density of sensory neurons varies among species; in humans, the OE is only about 9-10 cm2.
The olfactory receptors are embedded in the cilia of the...
The olfactory receptors are embedded in the cilia of the...
44.8K
01:24The Physiology of Taste
4.1K
The perception of a salty flavor is facilitated by sodium ions within the oral salivary fluid. Upon consumption of a salty substance, salt crystals disassemble, leading to the liberation of its constituents—Na+ and Cl- ions. These ions subsequently dissolve into the salivary fluid present in the oral cavity. The external environment of the gustatory cells experiences an elevation in Na+ concentration, thereby establishing a potent concentration gradient. This gradient propels the...
4.1K
01:20COPD: Pathogenesis and Clinical Features
437
Chronic obstructive pulmonary disease (COPD) is a group of lung conditions that progressively worsen over time, including chronic bronchitis and emphysema. This cluster of diseases collectively leads to a gradual and irreversible decline in lung function over time.
The primary cause for the onset of COPD is cigarette smoking and exposure to air pollution. These hazardous factors initiate a chain reaction within the lungs, resulting in chronic inflammation, damage to the airways, and a...
The primary cause for the onset of COPD is cigarette smoking and exposure to air pollution. These hazardous factors initiate a chain reaction within the lungs, resulting in chronic inflammation, damage to the airways, and a...
437