Why is neuronal death measurement critical for target validation in this model?

Neuronal death confirms on-target TRPV1 activation and provides a quantifiable endpoint to assess target engagement and pathway specificity in small fiber neuropathy models.

How does intraperitoneal administration support discovery pipeline consistency?

Intraperitoneal delivery ensures systemic exposure and reliable delivery to dorsal root ganglia, enabling reproducible TRPV1 engagement across study groups.

What quantitative measurements enable assessment of neuropathy progression?

Intraepidermal nerve fiber density in skin biopsies provides a quantitative, histomorphometric readout of sensory neurodegeneration over time.

Why are replication requirements essential for cross-functional collaboration?

Replication ensures model reliability and data consistency between discovery, pharmacology, and pathology teams, supporting aligned interpretation of target modulation effects.

What statistical analysis is required to interpret sensory neuropathy outcomes?

Group comparisons require parametric or non-parametric tests to determine significant differences in intraepidermal nerve fiber loss between treated and control cohorts.

Establishing a Mouse Model of Small Fiber Neuropathy Using Resiniferatoxin

JoVE Encyclopedia of Experiments

Neuroscience

0 views • 2:26 min • July 8th, 2025

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Begin with a solution of resiniferatoxin (RTX), a high-affinity agonist of the TRPV1 receptor—pain-sensitive ion channels expressed on sensory neurons.

Take an anesthetized adult mouse and administer RTX intraperitoneally.

The drug enters systemic circulation and reaches the dorsal root ganglia (DRG), a cluster of sensory neuron cell bodies located near the spinal cord.

RTX crosses the blood-nerve barrier and interacts with small-diameter sensory neurons in the DRG that abundantly express TRPV1.

RTX binding to TRPV1 activates the receptors, inducing a massive calcium ion influx into the neurons.

Intracellular calcium activates enzymes that degrade cell membrane phospholipids, cellular proteins, and DNA, ultimately leading to neuronal death.

Subsequently, the intraepidermal nerve fibers (IENFs), the peripheral terminals of small-diameter sensory neurons that innervate the skin, begin to degenerate.

This degeneration of IENFs results in the loss of sensory input from the skin, thereby establishing a small fiber neuropathy model.

To begin, put on personal protective equipment and take proper precautions while making the resiniferatoxin or RTX stock solution. Dilute one aliquot of 600 microliters in saline for the experiment, and divide the rest into 12-microliter aliquots for storage. For test mice, use eight-week-old adult male ICR mice, weighing between 35 and 40 grams. Administer a single dose of RTX solution intraperitoneally with a microinjection syringe. Next, inject a second group of mice with an equal volume of vehicle to serve as a control. After making all of the injections, house the mice in their home cages, and be certain that they have ad-lib access to food and water.