Evidence map›Paper›PMID 41245089›Full record

ArticlePNAS nexus2025

Automated pain assessment based on facial expression of free-moving mice.

Koji Kobayashi, Naoaki Sakamoto, Yusuke Miyazaki, Masahito Yamamoto, Takahisa Murata

Abstract read
In one paragraph

Article in PNAS nexus, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.

0numbers the graph read from it
0cells of the map it votes in
1citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

1 citing paper in PubMed.

  1. Review
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

5 authors.

Koji KobayashiLaboratory of Food and Animal Systemics, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657, Japan.
Naoaki SakamotoLaboratory of Animal Radiology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657, Japan.ORCID https://orcid.org/0000-0002-2347-1310
Yusuke MiyazakiLaboratory of Animal Radiology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657, Japan.ORCID https://orcid.org/0009-0005-9866-8977
Masahito YamamotoAutonomous Systems Engineering Laboratory, Graduate School of Information Science and Technology, Hokkaido University, Sapporo 060-0814, Japan.ORCID https://orcid.org/0000-0002-7326-3691
Takahisa MurataLaboratory of Food and Animal Systemics, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657, Japan.ORCID https://orcid.org/0000-0002-3328-0796

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Pain is a basic sensation associated with tissue injury. Although facial expression is a useful indicator of pain in mammals, its assessment in rodents requires expertise and experience. Here, we aimed to establish an automated pain assessment method using the facial images of free-moving mice. A convolutional neural network (CNN) was trained with the facial images of untreated mice and those subjected to acetic acid (AC)-induced pain. The trained CNN successfully predicted the faces of AC-, capsaicin-, and calcitonin gene-related peptide-induced pain that had not been used for CNN training. It also detected the analgesic effect of diclofenac, a nonsteroidal anti-inflammatory drug, against AC-induced pain. We used dimensionality reduction algorithms to select images with similar compositions and visualized the regions focused on by the CNN during predictions. The CNN focused on the head, forehead, ear, eye, cheek, and nose to predict pain or no pain. In conclusion, we established a method for automated pain assessment using the facial images of free-moving mice.

Indexed as

facial expressionmachine learningneural networkpain

Identifiers

PMID41245089
PMCPMC12617409

What OpenQuestion holds

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LicenceCC BY-NC
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Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.