Quantal Content Analysis
Quantal Content Analysis - Related Videos
15:04
A Neuronal and Astrocyte Co-Culture Assay for High Content Analysis of Neurotoxicity
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Cited by 46 •
2009
This article describes a novel protocol and reagent set designed for sensitive measurement of neurotoxic effects of compounds and treatments on co-cultures of neurons and astrocytes using high content analysis. Results demonstrate that high content analysis represents an exciting novel technology for neurotoxicity assessment.
07:44
Analysis of Fatty Acid Content and Composition in Microalgae
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Cited by 207 •
2013
A method for the determination of fatty acid content and composition in microalgae based on mechanical cell disruption, solvent based lipid extraction, transesterification, and quantification and identification of fatty acids using gas chromatography is described. A tripentadecanoin internal standard is used to compensate for the possible losses during extraction and incomplete transesterification.
09:16
Air-sampled Filter Analysis for Endotoxins and DNA Content
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2016
Two complementary analyses of atmospheric biological particles from air sampled filters are described herein: the extraction and detection of endotoxin, and of DNA.
11:38
High Content Screening Analysis to Evaluate the Toxicological Effects of Harmful and Potentially Harmful Constituents (HPHC)
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Cited by 23 •
2016
The objective of the study was to assess the biological impact of 15 cigarette smoke constituents using a combination of an impedance-based real time cell analyzer and a high-content screening (HCS)-based platform for toxicological assessment in vitro. This study provides information on effective doses, toxicity and modes of action of the tested compounds.
12:11
A Rhodopsin Transport Assay by High-Content Imaging Analysis
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Cited by 1 •
2019
Here, we described a high-content imaging method to quantify the transport of rhodopsin mutants associated with retinitis pigmentosa. A multiple-wavelength scoring analysis was used to quantify rhodopsin protein on the cell surface or in the whole cell.
FAQs
Quantal content analysis uses the miniature response as a reference unit rather than treating the evoked response as an indivisible signal. Dividing the evoked postsynaptic response by the average miniature response estimates the average number of quanta released by one stimulus. This converts synaptic strength into a release-related quantity that can be compared across conditions.
Miniature spontaneous responses are essential because each is attributed to one released quantum. Their size supplies the response scale needed to interpret a stimulus-evoked signal. If the reference miniature response changes, the estimated quantal content must be interpreted alongside that change, helping investigators avoid confusing altered postsynaptic sensitivity with altered presynaptic release.
The method separates two sides of synaptic transmission by comparing evoked and miniature responses. A difference in the stimulus-evoked signal can reflect the number of packets released, the postsynaptic response to each packet, or both. Examining the miniature response alongside the evoked response therefore helps localize whether a manipulation acts presynaptically or postsynaptically.
A basic workflow begins by measuring miniature spontaneous responses, then measuring the postsynaptic response produced by stimulation. The miniature responses establish the single-quantum reference, while the evoked response reflects the combined effect of the quanta released during that stimulus. Comparing these measurements yields an average quantal content for the condition being studied.
Researchers apply quantal content analysis when they need to determine whether synaptic strength changes because presynaptic release changed or because postsynaptic sensitivity changed. The approach is useful for examining synapses and neuromuscular junctions under developmental, disease-related, pharmacological, or genetic conditions, provided both response types can be compared.
An altered estimate means the relationship between the stimulus-evoked response and the single-quantum reference has changed. Interpreting that result requires considering both measurements: the change may reflect a different number of neurotransmitter packets released, altered postsynaptic sensitivity, or contributions from both. This makes quantal content useful for analyzing mechanisms rather than simply ranking synapses by strength.