A novel injury-free "two-hit" mouse migraine model revealed distinct temporal contributions of CGRP receptor activation in migraine-like pain, with both acute sumatriptan treatment and preventive anti-CGRP antibody showing efficacy.
Injury-free migraine modelFirst preclinical migraine model that produces CGRP-dependent pain without tissue injury — more accurately reflecting how human migraines develop
What the researchers found
Novel injury-free two-hit hyperalgesic priming model produced CGRP-dependent migraine-like pain in mice. Sumatriptan (acute) and anti-CGRP antibody (preventive) both showed efficacy. CGRP receptor activation had distinct temporal contributions to pain phases. Sex differences observed.
Why it matters
Better migraine models lead to better drugs. This injury-free model more closely mimics human migraine vulnerability and revealed that CGRP plays different roles at different time points — information that could optimize the timing of anti-CGRP treatments.
The numbers in context
3-day stress priming; 16-day latent sensitization; olcegepant preventive but not acute; sumatriptan acute but not preventive; nor-BNI prevented priming
How the study worked
Animal study. C57BL/6 mice (male and female). Two-hit priming (CGRP exposure) + subthreshold TRPA1 challenge (umbellulone). Cutaneous allodynia and grimace measurements. Sumatriptan and anti-CGRP antibody treatment. Temporal analysis of CGRP contribution.
Who was studied
Male and female C57BL/6 mice (and Sprague-Dawley rats for sumatriptan)
What this study cannot tell us
Mouse model — migraine experience in humans is more complex. TRPA1 trigger may not represent all migraine triggers. Sex differences in mice may not match human sex differences. Model validation against clinical endpoints limited.
How to read the evidence
Moderate evidence: well-characterized animal model validated with established migraine drugs. Novel translational approach.
When this study was published
Published 2021. Advanced migraine models incorporating vulnerability priming are being adopted by the field.
The bigger picture
Migraine research needs models that reflect the disease's episodic, vulnerability-based nature. This model's ability to test both acute and preventive treatments and reveal sex differences makes it valuable for developing next-generation migraine therapies.
Questions still open
- Does the temporal pattern of CGRP contribution match the clinical time course of migraine attacks?
- Could this model identify the optimal dosing schedule for anti-CGRP preventive treatments?
- Do sex differences in the model explain why migraine is 3x more common in women?
Common questions
Why is an injury-free model important for migraine?
Does this change how we think about CGRP in migraines?
Read the original research
A novel, injury-free rodent model of vulnerability for assessment of acute and preventive therapies reveals temporal contributions of CGRP-receptor activation in migraine-like pain.
Cephalalgia : an international journal of headache, 41(3), 305-317
Citation
Kopruszinski, Caroline M; Navratilova, Edita; Swiokla, Juliana; Dodick, David W; Chessell, Iain P; Porreca, Frank. (2021). A novel, injury-free rodent model of vulnerability for assessment of acute and preventive therapies reveals temporal contributions of CGRP-receptor activation in migraine-like pain.. Cephalalgia : an international journal of headache, 41(3), 305-317. https://doi.org/10.1177/0333102420959794