# Distinct µ-opioid ensembles trigger positive and negative fentanyl reinforcement

*PRI Rank #5 · Topics and Trends in Most Cited Neuropeptides and Animal Physiology Papers, Class of 2026*

*Canonical URL: https://pri.pepkio.com/top-papers/neuropeptides-and-animal-physiology/2026/rank-5*

| Field | Value |
| --- | --- |
| Rank | #5 |
| 18m citations | 47 |
| Journal | Nature |
| Year | 2024 |
| DOI | 10.1038/s41586-024-07440-x |
| Corresponding authors | Christian Lüscher |
| Institution | University of Geneva, Switzerland |

**Ranking page:** [Topics and Trends in Most Cited Neuropeptides and Animal Physiology Papers, Class of 2026](https://pri.pepkio.com/top-papers/neuropeptides-and-animal-physiology/2026)

**Paper link:** [10.1038/s41586-024-07440-x](https://doi.org/10.1038/s41586-024-07440-x)

## Topics

fentanyl · μ-opioid receptor · positive reinforcement · negative reinforcement · ventral tegmental area · central amygdala · GABA neurons · dopamine neurons · nucleus accumbens · opioid withdrawal · µ-opioid receptor knockdown · dopamine transients · Optogenetic manipulation · place aversion · lever pressing · neuronal ensembles · circuit adaptations · Opioid use disorder

## Cite this ranking

```
Pepkio Research Index (PRI). Topics and Trends in Most Cited Neuropeptides and Animal Physiology Papers, Class of 2026. https://pri.pepkio.com/top-papers/neuropeptides-and-animal-physiology/2026. Accessed 2026-07-31.

Zheng Su, Tinsley Li, Thematic Shifts in Early-High-Impact Cancer Genomics and Diagnostics Research: A Bibliometric and Semantic Analysis. bioRxiv 2026.07.04.736459; doi: https://doi.org/10.64898/2026.07.04.736459
```