Molecular memory
a Review by Manon Bonneau and Solenne Bochet (M2 PPCECC)
An article published on August 22, 2018 in Science et Vie made us perplex. This article has highlighted an experiment of David Glanzman. In this experiment he managed to isolate a memory and transfer it from one snail (Aplysia Californica) to another one. This goes against all our knowledge. Indeed, we have learned that memory and our memories are part of a neural network. So, they are not located at a specific place in our brain. A lot of brain area are involved to memorize information. Moreover, memories don’t reflect exactly the reality (e.g. false memories).
David Glanzman had built an experiment in four steps and he had used snails.
Firstly, a snail had to memorize an electric shock. In this step, the experimenter sent electric shock five times every twenty minutes to the animal’s tail. The snail retracts his tail to protect itself. After that, the snail was used to the electric shocks and he retracted his tail at the slightest shock.
Secondly, the experimenter took the memory with a syringe. He punctured a portion of the content of the neurons containing the snail’s memory.
Thirdly, the content of the syringe is injected into the brain in another snail called “naïve”.
Finally, the naive snail has acquired the same reflex of retraction of his tail. The experimenter concludes that reflex is a memory. Indeed, one day later, the naïve snail
has known the consequences of an electric shock as well as the one for which the memory was taken. For Glanzman the memory has been implanted into the naïve snail. This experience puts forward the molecular nature of memory.
The fact that a memory is injectable is quite revolutionary and unprecedented. If this experiment is applicable to humans, science could cure psychological disorder such as symptoms of post-traumatic stress in a snap of fingers. It would be enough to remove with a syringe all the traumatic memories. This is a crazy idea.
This idea is not consistent with our knowledge. If the memories are printed in molecules then it should be the exact reflection of the reality? Would false memories be altered molecules? Only few characteristics of memory are recorded at the molecular level? This discovery raises a lot of questions.
Key words :
- Injectable memories : souvenirs injectables
- Molecular : moléculaire
- Memory : mémoire
- Snail : escargot
- Electric shock : choc électrique