CB1 Cannabinoid Receptors Are Concentrated in Pain-Processing Spinal Cord Regions in Both Rats and Humans

CB1 receptors were preferentially concentrated in the superficial dorsal horn, the spinal cord's primary pain-processing area, in both sexes of rats and humans.

Parnell, Jessica et al.·Canadian journal of pain = Revue canadienne de la douleur·2023·Preliminary EvidenceAnimal StudyAnimal Study
RTHC-04834Animal StudyPreliminary Evidence2023RETHINKTHC RESEARCH DATABASErethinkthc.com/research

Quick Facts

Study Type
Animal Study
Evidence
Preliminary Evidence
Sample
Not reported

What This Study Found

CB1 immunoreactivity was significantly higher in the superficial vs deep dorsal horn in both species, conserved across sex. CB1 was not primarily on peptidergic afferents as thought. CNR1 but not CNR2 was robustly expressed in dorsal horn neurons.

Key Numbers

CB1 significantly higher in superficial vs deep dorsal horn. Conserved across species and sex. CNR1 robustly expressed; CNR2 not.

How They Did This

Immunohistochemistry on rat and human spinal cord tissue combined with single-cell RNA sequencing analysis.

Why This Research Matters

Understanding cannabinoid receptor location in pain circuits is fundamental to developing cannabis-based pain treatments.

The Bigger Picture

Cross-species validation strengthens relevance of preclinical pain research. Sex conservation suggests cannabinoid pain mechanisms should work similarly in men and women.

What This Study Doesn't Tell Us

Fixed tissue limitations. Limited human tissue. Did not assess functional activation.

Questions This Raises

  • ?Does CB1 concentration explain why cannabinoids work better for some pain types?
  • ?Could spinal CB1-targeted therapies avoid cognitive side effects?

Trust & Context

Key Stat:
CB1 pain circuit distribution conserved across species and sex
Evidence Grade:
Multi-method study with cross-species validation.
Study Age:
Published 2023.
Original Title:
Cannabinoid CB1 Receptor Expression and Localization in the Dorsal Horn of Male and Female Rat and Human Spinal Cord.
Published In:
Canadian journal of pain = Revue canadienne de la douleur, 7(2), 2264895 (2023)
Database ID:
RTHC-04834

Evidence Hierarchy

Meta-Analysis / Systematic Review
Randomized Controlled Trial
Cohort / Case-Control
Cross-Sectional / Observational
Case Report / Animal StudyOne case or non-human subjects
This study

Tests effects in animals (usually mice or rats), not humans.

What do these levels mean? →

Frequently Asked Questions

Where are cannabinoid receptors in pain pathways?

CB1 receptors are concentrated in the superficial dorsal horn of the spinal cord in both rats and humans.

Do males and females have the same cannabinoid receptor patterns?

Yes. CB1 distribution in the pain-processing region was conserved across sex.

Read More on RethinkTHC

Cite This Study

RTHC-04834·https://rethinkthc.com/research/RTHC-04834

APA

Parnell, Jessica; Martin, Newton; Dedek, Annemarie; Rudyk, Christopher; Landrigan, Jeffrey; Bellavance, Justin; VanDerLoo, Simon; Tsai, Eve C; Hildebrand, Michael E. (2023). Cannabinoid CB1 Receptor Expression and Localization in the Dorsal Horn of Male and Female Rat and Human Spinal Cord.. Canadian journal of pain = Revue canadienne de la douleur, 7(2), 2264895. https://doi.org/10.1080/24740527.2023.2264895

MLA

Parnell, Jessica, et al. "Cannabinoid CB1 Receptor Expression and Localization in the Dorsal Horn of Male and Female Rat and Human Spinal Cord.." Canadian journal of pain = Revue canadienne de la douleur, 2023. https://doi.org/10.1080/24740527.2023.2264895

RethinkTHC

RethinkTHC Research Database. "Cannabinoid CB1 Receptor Expression and Localization in the ..." RTHC-04834. Retrieved from https://rethinkthc.com/research/parnell-2023-cannabinoid-cb1-receptor-expression

Access the Original Study

Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.

This study breakdown was produced by the RethinkTHC research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.