Nasal Potential Difference
Nasal Potential Difference - Related Videos
09:47
Standardized Measurement of Nasal Membrane Transepithelial Potential Difference (NPD)
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Cited by 32 •
2018
Here, we present a standardized protocol to measure the nasal potential difference (NPD). Cystic fibrosis transmembrane conductance regulator (CFTR) and epithelial sodium channel (ENaC) function are evaluated by the change in the voltage across the nasal epithelium after superfusion of solutions that modify ion channel activity, providing an outcome measure.
08:55
Nasal Potential Difference to Quantify Trans-epithelial Ion Transport in Mice
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Cited by 2 •
2018
Here, we present a protocol to measure nasal potential difference in mice. The test quantifies the function of transmembrane ion transporters such as the cystic fibrosis transmembrane conductance regulator and the epithelial sodium channel. It is valuable to evaluate the efficacy of novel therapies for cystic fibrosis.
01:16
Electric Potential and Potential Difference
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2023
Suppose a positive test charge moves away from a positive static charge, then the Coulomb force does positive work, and its electric potential energy decreases. The potential energy per unit charge is defined as the electric potential. The electric potential is independent of the test charge. When a test charge moves from the initial to the final position, the electric potential difference between those positions is defined as the ratio of the change in the potential energy to the charge on the...
07:30
Just-noticeable Differences
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2023
Source: Laboratory of Jonathan Flombaum—Johns Hopkins University Psychophysics is a branch of psychology and neuroscience that tries to explain how physical quantities are translated into neural firing and mental representations of magnitude. One set of questions in this area pertains to just-noticeable differences (JND): How much does something need to change in order for the change to be perceivable? To pump intuitions about this, consider the fact that small children grow at an enormous...
10:38
Culturing of Human Nasal Epithelial Cells at the Air Liquid Interface
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Cited by 135 •
2013
Nasal epithelial cells, obtained through superficial scrape biopsy of human volunteers, are expanded and transferred onto tissue culture inserts. Upon reaching confluency, cells are grown at air liquid interface, yielding cultures of ciliated and non-ciliated cells. Differentiated nasal epithelial cell cultures provide viable experimental models for studying the respiratory mucosa.
FAQs
ENaC-mediated sodium absorption and CFTR-mediated chloride secretion contribute to the measured epithelial voltage. Blocking ENaC with amiloride tests the sodium-absorptive component, while chloride-free solutions or agonist-containing solutions probe chloride transport, particularly CFTR-linked activity. Comparing voltage responses across these conditions helps separate channel contributions rather than relying on a single baseline reading.
These interventions act as functional challenges for distinct ion-transport pathways. Amiloride reduces the contribution from epithelial sodium absorption, whereas chloride-free or agonist-containing solutions reveal changes associated with chloride secretion. The resulting voltage shifts provide pharmacological evidence about channel activity and can indicate whether a transport defect responds to a specific experimental condition.
Nasal Potential Difference provides a functional readout of epithelial ion transport in living tissue. In cystic fibrosis-related channel dysfunction, the response pattern can reflect impaired CFTR-associated chloride secretion and altered sodium transport. This complements molecular measurements by showing how channel activity behaves at the epithelial level, which is relevant when assessing pharmacological correction.
The procedure places an electrode in contact with the nasal mucosa and a reference electrode on reference tissue. The nasal surface is then perfused with defined solutions while voltage is recorded. Researchers compare the signal during baseline conditions and after selected interventions, such as amiloride, chloride-free solutions, or agonist-containing solutions.
Reliable measurements require electrodes that contact the nasal mucosa and reference tissue, together with defined solutions for surface perfusion. The composition of those solutions matters because it determines whether sodium absorption or chloride secretion is being challenged. Recording voltage across these controlled conditions allows responses to be linked to specific epithelial transport processes.
Researchers use Nasal Potential Difference to characterize cystic fibrosis-related channel dysfunction and to evaluate whether investigational drugs restore CFTR activity. The assay can serve as a functional outcome alongside molecular or clinical measures. Its value is greatest when treatment-related voltage changes are interpreted under defined pharmacological and solution conditions that probe ion transport.