Some billions of synapses connect our nerve cells and keep our memories intact and alive for decades with the help of self-copying clusters or oligomers of a synapse protein, a study has revealed.
It supports a surprising new theory about memory and may have a profound impact on explaining other oligomer-linked functions and diseases in the brain, including Alzheimer's disease and prion diseases, the journal Cell reported.

"Self-sustaining populations of oligomers located at synapses may be the key to the long-term synaptic changes that underlie memory," said Kausik Si, associate investigator at the Stowers Institute.

Kausik's investigations in this area began nearly a decade ago during his doctoral research in the Columbia University lab of Nobel-winning neuroscientist Eric Kandel, according to a univesity statement.

He found that in the sea slug Aplysia californica-long been favoured by neuroscientists for memory experiments because of its large, easily-studied neurons, a synapse-maintenance protein CPEB, (Cytoplasmic Polyadenylation Element Binding protein) has an unexpected property.

In the new study, Kausik and his colleagues examined a Drosophila fruit fly CPEB protein known as Orb2. Like its counterpart in Aplysia, it forms oligomers within neurons (nerve cells).

"We found that these Orb2 oligomers become more numerous in neurons whose synapses are stimulated, and that this increase in oligomers happens near synapses," said Amitabha Majumdar, postdoctoral researcher in Si's lab, who led the study.