de la Peña Lab

Circular RNAs in human pain · UNM School of Medicine

The hidden RNA layer of human pain

We study circular RNAs (circRNAs), a class of RNA that many standard sequencing methods miss, in human pain-sensing neurons. We mapped the circRNA landscape of human dorsal root ganglia and found that opioid exposure is associated with changes in them. Our goal is to add this hidden layer to the human pain atlas and turn it into new non-addictive treatments.

43circular RNAs changed in opioid-exposed human DRG (PAIN 2026, Editor's Choice)
P2RY11a morphine-induced receptor gene that mice and rats do not have (Cells 2026)
1.5×New Mexico's opioid overdose death rate compared with the U.S. (24.1 vs 16.0 per 100,000 in 2024, KFF)

Our focus

The circular RNA layer of human pain

What they are

Loops of RNA

Circular RNAs form when a gene's RNA is spliced back onto itself. They are extraordinarily enriched in the mammalian brain and highly enriched in synapses.

Rybak-Wolf et al., Mol Cell 2015
Why they are missed

Invisible to standard methods

Human pain atlases were built to read linear RNAs with poly(A) tails, the RNAs that define cell types. CircRNAs lack a poly(A) tail, and in RNA sequencing they are distinguished from linear RNA only by reads spanning the back-splice junction, so these methods largely miss them.

Szabo and Salzman, Nat Rev Genet 2016
What we found

Mapping human DRG

Using total RNA sequencing of donor DRG, we characterized the circRNA landscape of human pain-sensing tissue and showed that opioid exposure is associated with lower overall abundance, including reduced circNTRK2.

Koch et al., PAIN 2026

Our goal is to add the circular RNA layer to the human pain atlas, cell type by cell type, and to test which circRNAs shape pain and the response to opioids. New to circRNAs? Start with our circRNA in pain resource.

Why we study human neurons

Many pain treatments that work in rodents have not worked in people. We work with dorsal root ganglia donated through New Mexico Donor Services and with human stem cell-derived neurons, so our findings start where patients are.

Human-specific biology

Some human pain genes are missing in mice

Morphine strongly switches on P2RY11 in human pain-sensing neurons. Mice and rats lack this gene, so rodent studies cannot detect it.

Read the paper
Individual differences

People's nerve cells respond differently

Neurons from different human donors responded differently to gabapentin, a common pain drug, and RNA sequencing of DRG from the more responsive donor pointed to the pathways involved.

Read the paper

Latest papers

All publications

Meet the team

All people
  • June Bryan de la PeñaPrincipal Investigator
  • Bon CampomayorPostdoctoral Fellow
  • Jenna DemeterResearch Scientist
  • Maddy KochPhD Student
  • Quisha LeyritaMS Student
  • Gianluca FuggitiMedical Student
  • Madison HochreinMedical Student
  • Sean McNallyMedical Student
  • Gracie SwensenMedical Student
  • Manuel Bustillos LopezUndergraduate
  • Ibrahim EldenawiUndergraduate
  • Jeanette MontoyaUndergraduate

Research philosophy

Research is the freedom of being able to ask questions, make hypotheses, test them, make mistakes, and solve problems along the way. It is not just about publishing papers or getting grants, which are also important, but having the ability to use creativity, follow clues, and work hard, hoping that one day what we have learned in the lab can positively impact the lives of those who are suffering from chronic conditions such as ongoing pain.

Join us

We are recruiting graduate students, postdoctoral fellows, and undergraduates interested in RNA biology, human sensory neuroscience, and pain.

How to apply
Dr. June Bryan de la Peña

June Bryan I. de la Peña, MS, PhD

Assistant Professor of Research, Department of Anesthesiology & Critical Care Medicine

Secondary appointment, Department of Neurosciences

University of New Mexico School of Medicine

Full bio

Supported by the National Institutes of Health (NIH HEAL Initiative through NCATS and NINDS, and NIGMS), UNM Health Sciences Center, the RNA Society, and Anthropic. See funding