# Hibernation in Mice Causes Major Synapse Loss

Scientists investigate how a hibernation-like state affects memory in mice.

- **Source:** [Ars Technica - All content](https://brifing.si/source/b728770c-8dda-457a-8986-84879c9fc42c)
- **Published:** 2026-08-22
- **Original article:** <https://arstechnica.com/science/2026/08/memories-stick-around-even-after-half-the-synapses-are-gone/>
- **On Brifing:** https://brifing.si/s/90b66d70-b0ad-4d04-85df-edf1a2680f1f

## Memory and Synapse Relationship

The scientific community believes that memory is formed when connections between neurons strengthen and physically grow during learning. However, these connections can change significantly over time. Kazumasa Tanaka from the Okinawa Institute of Science and Technology notes that these changes become noticeable within just a few days. This raises the question of how memory can remain stable over long periods.

## Artificial Hibernation Experiment

Tanaka's team induced an artificial hibernation-like state in mice to explore this question. This state appeared to erase the condition of more than half of the mice's synapses. Surprisingly, the mice seemed to retain their memories. This finding poses new questions about memory mechanisms.

## Hibernation and Mammals

While hibernation is a trait of animals like squirrels, hamsters, and bears, the neural circuit that triggers it is conserved across all mammals. Even mice, which never hibernate in the wild, possess this circuit. This provides clues about the evolutionary origins of hibernation.

## Role of Q Neurons

In June 2020, a team led by Takeshi Sakurai from the University of Tsukuba developed a technique to artificially activate this hibernation circuit. By activating Q neurons in a region of the hypothalamus, this state can be induced. This technique opens new avenues in neurological research.

## Effects of Synapse Loss

The loss of synapses in mice reveals surprising results about the physical basis of memory. Despite the loss of a significant portion of synapses, memory appears to be preserved, suggesting that memory storage mechanisms are more complex. This finding could lead to new theories in neuroscience.

## Research Potential

This study not only advances our understanding of memory mechanisms but also holds promise for treating neurodegenerative diseases. Understanding how synapse loss does not affect memory could help develop new treatments for conditions like Alzheimer's disease.

## Future Research

Scientists now plan to investigate whether these findings apply to humans. If similar mechanisms operate in humans, this could revolutionize the treatment of memory loss and neurological diseases. Research in this area is progressing rapidly.

## Conclusion and Significance

This research challenges our fundamental understanding of how memory works. Findings showing that synapse loss does not erase memory indicate a potential paradigm shift in neuroscience. This discovery is seen as a major step forward in both basic science and medicine.

## Sources covering this story

- https://arstechnica.com/science/2026/08/memories-stick-around-even-after-half-the-synapses-are-gone/ — 

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_Summary written by Brifing from the original reporting. Copyright in the original article belongs to its publisher; read the full piece at the link above._