The cuttlefish brain has a memory that "never fades"

Science and Technology Daily News (intern reporter Zhang Jiaxin) Cuttlefish can remember the time and place of specific events, and even in the last few days of their lives, this memory is still there. The findings, published in the recently published Proceedings of the Royal Society, Are the first to show that animals' memory of specific events does not deteriorate with age.

Researchers from the University of Cambridge in the United Kingdom, the Woods Hole Marine Biology Laboratory in the United States and the University of Caen in France conducted memory tests on 24 common cuttlefish. Half of them are 10-12 months old and not yet mature; the other half are 22-24 months old cuttlefish, equivalent to humans in their 90s.

"Cuttlefish can remember what they ate when and where they are and use this to guide their future eating decisions." Surprisingly, despite other signs of aging such as muscle loss and loss of appetite, their memory does not decline with age. The paper's first author, Dr Alexandra Schneier of the University of Cambridge's Department of Psychology, said.

As humans age, we gradually lose the ability to remember experiences that took place at specific times and places, such as what dinner we had last Tuesday. This decline in memory, called "episodic memory," is thought to be due to decreased hippocampal function in the brain.

However, cuttlefish do not deteriorate until the last two to three days of their lives. The researchers say this is because the structures in cuttlefish brains that are related to learning and memory are "vertical lobes" and do not have hippocampus. This could explain why the situational memory of cuttlefish is not affected by age.

To test cuttlefish's memory of when and where to get which foods, the researchers first trained cuttlefish to approach specific locations marked with black and white flags in the tank. Then, through training, cuttlefish learn that the two foods they often eat can be obtained after a specific flag waving and a specific time delay. One of the places offers king shrimp for cuttlefish (which is a food that cuttlefish don't like very much). Another place serves live grass shrimp that they prefer, but only every 3 hours. This process was repeated for 4 weeks.

In addition, the two feeding locations are different every day. All cuttlefish, regardless of age, observe the food that first appears on each flag and use this to calculate which feed point is the best when the flag is waved. This suggests that, unlike humans, the episodic memory of cuttlefish does not decay with age.

Many older cuttlefish have as good or better memory during the test phase as younger cuttlefish. Researchers believe this ability may help wild cuttlefish remember who they have mated with.

Cuttlefish have a short lifespan, mostly around two years old, and only breed at the end of their lives. Researchers believe that cuttlefish help them reproduce more broadly by remembering where, when, and with whom they mate.

Source: Science and Technology Daily