How to freeze a memory: putting worms on ice stops them forgetting

🌈 Abstract

The article discusses the short-term memory of roundworms (Caenorhabditis elegans) and how environmental factors like temperature and the drug lithium can affect their memory retention.

🙋 Q&A

[01] Roundworm Memory and Environmental Factors

1. What is the typical memory retention of roundworms?

• Roundworms have short memories, forgetting new information just 2-3 hours after learning it.

2. How does cooling affect roundworm memory?

• When put on ice, roundworms can retain their memories for at least 16 hours. However, if they are allowed to gradually acclimate to the cold before training, they forget information as quickly as usual.
• The key to this memory preservation seems to be a rapid cooling process. Slow cooling does not provide the same memory-retaining effect.

3. How does the drug lithium affect roundworm memory?

• Giving roundworms the drug lithium allows them to retain their memories for longer, even at room temperature.
• This is likely because lithium inhibits an enzyme that produces a signaling molecule called diacylglycerol, which is involved in the "forgetting switch" in roundworms.

4. What other factors affect roundworm memory retention?

• Mutant roundworms with unusually rigid cell membranes were also slower to forget memories, even at room temperature. This suggests that physical hardening of the cell membrane can delay forgetting.

[02] Implications and Future Research

1. Why do roundworms forget memories so quickly?

• The researchers question whether there may be an evolutionary reason for roundworms to only retain memories for a short duration, rather than maintaining them longer.

2. What other organisms will the researchers investigate?

• The researchers plan to study whether similar memory phenomena occur in other cold-tolerant organisms, such as tardigrades and turtles.