Deleting neuropeptide Y from sensory neurons had no effect on neuropathic pain in mice, revealing that pain-inhibiting NPY in the spinal cord comes from local interneurons, not sensory neurons.
Zero effect on painGenetically deleting neuropeptide Y from sensory neurons — despite its dramatic upregulation after nerve injury — had no impact on mechanical, cold, or ongoing neuropathic pain in two different mouse models.
What the researchers found
Nerve injury causes sensory neurons to start producing neuropeptide Y (NPY) — a pain-modulating peptide — for the first time. Researchers genetically deleted NPY specifically from sensory neurons in mice to test whether this newly produced NPY contributes to neuropathic pain. Surprisingly, removing NPY from sensory neurons had no effect on mechanical pain, cold pain, or ongoing pain in two different nerve injury models. The study found that NPY's pain-inhibiting role in the spinal cord is actually mediated by spinal cord interneurons releasing NPY, not by the sensory neurons themselves. This overturns a long-held assumption about the source of pain-modulating NPY after nerve injury.
Why it matters
Understanding where pain-modulating peptides come from in the nervous system is critical for developing targeted pain therapies. For years, the dramatic upregulation of NPY in sensory neurons after nerve injury was assumed to be functionally important for neuropathic pain. This study shows that assumption was wrong — the pain-relevant NPY comes from spinal cord interneurons instead. This redirects therapeutic targeting efforts toward the spinal cord rather than peripheral sensory neurons for NPY-based pain treatments.
The numbers in context
2 nerve injury models (SNI, tSNI) · NPY Y1 receptor antagonist BIBO3304 used · Conditional knockout in DRG sensory neurons
How the study worked
Researchers created conditional knockout mice (Pirt-NPY) that lacked the NPY gene specifically in dorsal root ganglion sensory neurons while maintaining normal NPY expression in the brain and spinal cord interneurons. They tested these mice and wild-type controls in two nerve injury models (spared sural nerve injury and spared tibial nerve injury), measuring static mechanical allodynia, dynamic mechanical allodynia, cold allodynia, and ongoing pain using conditioned place preference to gabapentin. They also tested whether the NPY Y1 receptor antagonist BIBO3304 could reinstate pain sensitivity after recovery.
Who was studied
Conditional NPY knockout mice (Pirt-NPY) and wild-type controls subjected to nerve injury models
What this study cannot tell us
This is a mouse study, and the relevance of these findings to human neuropathic pain is uncertain. The conditional knockout approach, while elegant, may have incomplete deletion efficiency. The study focused on specific nerve injury models that may not represent all forms of neuropathic pain. As a bioRxiv preprint, these findings have not yet undergone peer review.
How to read the evidence
This is a well-designed animal study using conditional genetic knockout and multiple pain models, providing strong mechanistic evidence. However, it remains preclinical (mice only) and is currently a preprint that has not yet been peer-reviewed.
When this study was published
Published as a 2025 bioRxiv preprint, this is very recent and has not yet been peer-reviewed. The findings challenge a long-standing assumption in pain neuroscience and, if confirmed through peer review, could significantly redirect NPY-focused pain research.
The bigger picture
Neuropeptide Y is one of the most abundant neuropeptides in the nervous system and has long been a target for pain research. The dramatic upregulation of NPY in sensory neurons after nerve damage was one of the most reproducible findings in pain neuroscience, leading many researchers to focus on this source. By definitively showing that sensory neuron NPY is not the pain-relevant pool, this study redirects the field toward spinal cord interneurons as the true therapeutic target for NPY-based pain interventions.
Questions still open
- If sensory neuron NPY doesn't modulate pain, what is its functional purpose after nerve injury?
- Could therapies that boost NPY release from spinal cord interneurons provide effective neuropathic pain relief?
- Do these findings apply to other pain-modulatory peptides that are also upregulated in sensory neurons after nerve injury?
Common questions
What is neuropeptide Y and what does it do?
Why does this matter for pain treatment?
Read the original research
De novo expression of neuropeptide Y in sensory neurons does not contribute to peripheral neuropathic pain.
bioRxiv : the preprint server for biology
Citation
Cooper, A H; Nie, A; Hedden, N S; Herzog, H; Taylor, B K. (2025). De novo expression of neuropeptide Y in sensory neurons does not contribute to peripheral neuropathic pain.. bioRxiv : the preprint server for biology. https://doi.org/10.1101/2025.01.25.634591