We’re used to the idea that we become more forgetful with age. As time passes, our memories naturally fade and weaken, and that’s if we’re lucky enough to avoid traumatic accidents or diseases like Alzheimer’s. But Reut Shema, from the Weizmann Institute of Science in Israel, has found a possible way of preventing this decline, and even reversing it.
By loading the brains of rats with a protein called PKMzeta, she managed to strengthen their memories, even old and faded ones. “Multiple old memories were robustly enhanced. These results have no precedent,” says Todd Sacktor, who led the study together with Yadin Dudai.
PKMzeta is the engine of memory. This single protein behaves like a machine that constantly works to keep our memories intact. Switch it off, and we forget things permanently. It’s our lone defence against a constant tide of forgetfulness that threatens to revert our brains back to a blank slate (see “Exposing the memory engine”).
You’ve got the phone number of a hot date – a vital piece of information that you need to keep in a safe place. You write it in a notepad, you save it on a file in your computer and you try to commit it to memory. This third method – the one involving your brain – is very different to the others.
In the other formats, stability is the norm. The ink on the paper won’t vanish (at least not for centuries). The magnetic information on the hard drive won’t spontaneously rearrange itself. Unless either material suffers physical damage, the information recorded within them will stand the test of time. In your brain, the fate of information is much less certain.
In the last decade, scientists have found that it takes active and unrelenting effort to keep our memories intact. Even long-term memories are constantly on the verge of being erased. To keep them stable, we need to continually recreate a protein called PKMzeta. This molecule is the engine of memory, constantly whirring to store information in our brains. Give the engine a boost, and old memories gain a new lease on life. Switch it off, and we forget things…. permanently.
Last year, I interviewed Todd Sacktor for a feature on fear and memory in Eureka, the Times’s monthly science supplement. Sacktor discovered that a protein called PKMzeta is vital for storing memory and in his latest study, he shows that adding more of this protein in the brain can strengthen even old, faded memories. (See “Single protein can strengthen old faded memories”).
This post collates my two interviews with Sacktor – the first was done last year, and the second last night. The transcripts should act as a companion piece to my news story on his latest study, and my longer feature explaining the history of PKMzeta research and details about how this “memory engine” works.