MEMORIES ‘TRANSPLANTED’ FROM ONE CREATURE TO ANOTHER
In a world first, researchers at UCLA claim to have successfully transferred a memory from one sea slug to another using RNA. RNA is a molecule involved in the carrying of genetic instruction and the building of proteins.
The researchers periodically gave mild electric shocks to the tails of a species called Aplysia californica, or the California sea hare, over 24 hours in order to provoke their defensive withdrawal reflex. When subsequently tapped, the animals displayed a defensive contraction that lasted for 50 seconds. By contrast, sea slugs that had not been given the shocks contracted for about one second.
They then extracted RNA from the nervous systems of sea hares that received the tail shocks, and injected it into seven animals that had not received any shocks. They found that these ones then displayed a defensive contraction that lasted an average of about 40 seconds when tapped.
“It’s as though we transferred the memory,” said UCLA’s Brain Research Institute’s Prof David Glanzman. “I think in the not-too-distant future, we could potentially use RNA to ameliorate the effects of Alzheimer’s disease or post-traumatic stress disorder.”
The finding questions the current theory that memories are stored in synapses. Synapses are junctions between two nerve cells, consisting of a minute gap across which chemical signals are carried by messenger chemicals called neurotransmitters. Glanzman, however, proposes a new theory in which memories are stored in the nucleus of neurons.
“If memories were stored at synapses, there is no way our experiment would have worked,” said Glanzman.