---
title: "Mouse · Animals and other organisms · Entities · Simulation Hypothesis"
url: https://simulation-hypothesis.com/entities/mouse
description: "About 71 million neurons. Mice show facial expressions of pain that can be measured."
license: https://creativecommons.org/licenses/by/4.0/
credit: "Ross Allan Dahl, Simulation Hypothesis (simulation-hypothesis.com)"
---

[Entities](https://simulation-hypothesis.com/entities) › Animals and other organisms › Mammals

# Mouse

Mus musculus

About 71 million neurons. Mice show facial expressions of pain that can be measured.

Neurons

70.9 million measured  · whole brain (isotropic fractionator) 

Herculano-Houzel S, Mota B, Lent R (2006). Cellular scaling rules for rodent brains. PNAS 103:12138-12143\. doi:10.1073/pnas.0604911103.

In the cerebral cortex (or bird pallium)

about 13.7 million

Herculano-Houzel S, Mota B, Lent R (2006). Cellular scaling rules for rodent brains. PNAS 103:12138-12143\. doi:10.1073/pnas.0604911103.

## Evidence

* Mice show a facial expression that codes for pain.  
Langford DJ, Bailey AL, Chanda ML, Clarke SE, et al. (2010) Coding of facial expressions of pain in the laboratory mouse. Nat Methods 7(6):447-449\. doi:10.1038/nmeth.1455.

The [New York Declaration on Animal Consciousness](https://sites.google.com/nyu.edu/nydeclaration/declaration) (2024) finds strong scientific support for conscious experience in mammals and birds.

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