Objective: Assessment of itch behavior induced by chloroquine in wild-type and mutant mice to evaluate Mrgpr-dependent itch responses and identify itch-selective neurons
This is a Chloroquine-induced Itch Response Testing protocol using mouse as the model organism. The procedure involves 9 procedural steps, 3 materials. Extracted from a 2009 paper published in Cell.
Model and subjects
mouse • wild-type and mutant mice (Mrgpr gene cluster knockouts) • unknown • Not specified • Not specified
Study window
Estimated timing pending
Core workflow
Chloroquine-induced itch testing in wild-type mice • Chloroquine-induced itch testing in mutant mice • Histamine-induced itch testing
Primary readouts
Key equipment and reagents
Verified items
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Direct vendor links
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Administer chloroquine to wild-type mice and assess itch behavior response
Note: Baseline comparison group for mutant mice lacking Mrgpr genes
“Mice lacking a cluster of Mrgpr genes display significant deficits in itch induced by CQ but not histamine”
Administer chloroquine to mutant mice lacking Mrgpr gene cluster and assess itch behavior response
Note: Test group to evaluate Mrgpr-dependent itch responses
“Mice lacking a cluster of Mrgpr genes display significant deficits in itch induced by CQ but not histamine”
Administer histamine to both wild-type and mutant mice to assess histamine-dependent itch responses
Note: Control to demonstrate that Mrgpr-deficient mice retain normal histamine-induced itch
“Mice lacking a cluster of Mrgpr genes display significant deficits in itch induced by CQ but not histamine”
Activate MrgprC11-expressing neurons with BAM8-22 agonist and assess itch induction in wild-type and mutant mice
Note: Demonstrates functional role of MrgprC11 in itch sensation
“Activation of these neurons with MrgprC11-specific agonist BAM8-22 induces itch in wild-type but not mutant mice”
Evaluate direct excitation of sensory neurons by chloroquine in an Mrgpr-dependent manner
Note: Cellular-level assessment of CQ responsiveness
“CQ directly excites sensory neurons in an Mrgpr-dependent manner”
Test chloroquine activation of mouse MrgprA3 and human MrgprX1 to establish receptor specificity
Note: Identifies specific Mrgpr isoforms responsible for CQ-induced itch
“CQ specifically activates mouse MrgprA3 and human MrgprX1”
Evaluate MrgprA3 requirement for chloroquine responsiveness using knockout or knockdown approaches
Note: Demonstrates necessity of MrgprA3 for CQ-induced itch
“Loss- and gain-of-function studies demonstrate that MrgprA3 is required for CQ responsiveness in mice”
Evaluate effects of MrgprA3 overexpression or enhanced activation on chloroquine responsiveness
Note: Demonstrates sufficiency of MrgprA3 for CQ-induced itch
“Loss- and gain-of-function studies demonstrate that MrgprA3 is required for CQ responsiveness in mice”
Assess co-expression of histamine responsiveness, Gastrin-Releasing Peptide, and MrgprC11 in MrgprA3-expressing neurons
Note: Characterizes molecular profile of itch-selective neurons
“MrgprA3-expressing neurons respond to histamine and co-express Gastrin-Releasing Peptide, a peptide involved in itch sensation, and MrgprC11”
This section explains what the experiment is doing, which readouts matter, what the data artifacts usually look like, and how the analysis should flow from raw capture to reported result.
Assessment of itch behavior induced by chloroquine in wild-type and mutant mice to evaluate Mrgpr-dependent itch responses and identify itch-selective neurons
Objective
Assessment of itch behavior induced by chloroquine in wild-type and mutant mice to evaluate Mrgpr-dependent itch responses and identify itch-selective neurons
Subjects
From papermouse • wild-type and mutant mice (Mrgpr gene cluster knockouts) • unknown • Not specified • Not specified
Cohort notes
From paperStudy includes both wild-type and mutant mice lacking Mrgpr gene clusters; MrgprA3-expressing neurons evaluated
Chloroquine-induced itch testing in wild-type mice (Not specified)
Chloroquine-induced itch testing in mutant mice (Not specified)
Histamine-induced itch testing (Not specified)
BAM8-22 agonist activation testing (Not specified)
Itch behavior response to chloroquine in wild-type mice
From paperNot specified in provided text
Artifact type
Endpoint measurements summarized by group or timepoint
Comparison focus
Compare endpoint magnitude between groups, timepoints, or both
Itch behavior response to chloroquine in Mrgpr-deficient mutant mice
From paperNot specified in provided text
Artifact type
Endpoint measurements summarized by group or timepoint
Comparison focus
Compare endpoint magnitude between groups, timepoints, or both
Itch behavior response to histamine in both wild-type and mutant mice
From paperNot specified in provided text
Artifact type
Endpoint measurements summarized by group or timepoint
Comparison focus
Compare endpoint magnitude between groups, timepoints, or both
Direct sensory neuron excitation by chloroquine
From paperNot specified in provided text
Artifact type
Endpoint measurements summarized by group or timepoint
Comparison focus
Compare endpoint magnitude between groups, timepoints, or both
Itch behavior response to chloroquine in wild-type mice
From paperRaw artifact
Per-sample or per-animal endpoint measurements collected during the experiment
Processed artifact
Structured table with cleaned measurements ready for comparison
Final reported form
Summary statistics and between-group or across-timepoint comparisons
Itch behavior response to chloroquine in Mrgpr-deficient mutant mice
From paperRaw artifact
Per-sample or per-animal endpoint measurements collected during the experiment
Processed artifact
Structured table with cleaned measurements ready for comparison
Final reported form
Summary statistics and between-group or across-timepoint comparisons
Itch behavior response to histamine in both wild-type and mutant mice
From paperRaw artifact
Per-sample or per-animal endpoint measurements collected during the experiment
Processed artifact
Structured table with cleaned measurements ready for comparison
Final reported form
Summary statistics and between-group or across-timepoint comparisons
Direct sensory neuron excitation by chloroquine
From paperRaw artifact
Per-sample or per-animal endpoint measurements collected during the experiment
Processed artifact
Structured table with cleaned measurements ready for comparison
Final reported form
Summary statistics and between-group or across-timepoint comparisons
Acquisition
Collect raw experimental outputs with enough metadata to preserve sample identity, condition, and timing.
Preprocessing / cleaning
Not specified in provided text
Scoring or quantification
Quantify the primary readouts for this experiment: Itch behavior response to chloroquine in wild-type mice; Itch behavior response to chloroquine in Mrgpr-deficient mutant mice; Itch behavior response to histamine in both wild-type and mutant mice; Direct sensory neuron excitation by chloroquine.
Statistical comparison
Statistical method not yet structured for this page.
Reporting output
Report representative outputs alongside summary comparisons for Itch behavior response to chloroquine in wild-type mice, Itch behavior response to chloroquine in Mrgpr-deficient mutant mice, Itch behavior response to histamine in both wild-type and mutant mice, Direct sensory neuron excitation by chloroquine.
Source links and direct wording from the methods section for validation and deeper review.
Citation
Qin Liu et al. (2009). Sensory Neuron-Specific GPCR Mrgprs Are Itch Receptors Mediating Chloroquine-Induced Pruritus. Cell
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Source access
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Steps
9
Evidence Quotes
12
Protocol Items
3
Linked Products
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Pending
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Steps
9
Evidence
12
Specific Products
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Canonical Sync
Pending
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