Researchers from the Weizmann Institute of Science in Israel and New York’s SUNY Downstate Medical Center have been successful in manipulating a brain enzyme in rats, protein kinase M Zeta (PKMzeta) to improve memory. They believe this discovery could aid in developing treatment for those who suffer from memory loss and dementia.

Their findings were published in the journal Science, and since its publication has generated great interest among neuroscientists. What is even more exciting about this study is the not only found a way to treat the memory loss, but enhance memory of things that had been lost in memory for a long time.

Professor Toss Sacktor and his team, working on a grant from the U.S. National Health Institute of Mental Health, were able to manipulate the enzyme to erase long-term memories, and reverse the process, by bringing back memories that had been erased.

“Our study is the first to demonstrate that, in the context of a functioning brain in a behaving animal, a single molecule, PKMzeta, is both necessary and sufficient for maintaining long-term memory,” Sacktor said.

What sets this enzyme apart from other recent studies on memory enhancement, the PKMzeta mechanism appears to work any time. “It is not dependent on exploiting time-limited windows, when a memory becomes temporarily fragile and changeable – like just after learning and upon retrieval – which may expire as a memory grows older,” said Sacktor.

“This pivotal mechanism could become a target for treatments to help manage debilitating emotional memories in anxiety disorders, and for enhancing faltering memories in disorders of aging,” said NIMH Director Dr. Thomas Insel.

Studies going back five years have shown that even weeks after the rats had learned to associate the smell of saccharin with nausea, and backed away from the sweet taste they liked previously, the sweet tooth of the rats returned within a couple hours after receiving a chemical that blocked the PKMzeta.  Dudai and Sacktor were able to restore their long-term memories to the pleasure of the saccharin.

In another part of the study the researchers had paired the same genetic engineering techniques of the aversive learning model to both confirm their earlier studies, and reverse the effect by increasing PKMzeta. They inserted a virus to infect the neocortex with the PKMzeta gene, resulting in over expression of the enzyme and memory enhancement.

For the opposite effect they introduced a mutant, inactive form of the enzyme that replaced the naturally occurring one, and erased the memory – just as the chemical blocker did.

This brought up other questions, since these result affected were generally applied to multiple memories stores in a targeted area of the brain, how could it relate to specific memories in future applications?

The researchers believe they may have turned up a clue that may begin to answer that question. “One explanation of the memory enhancement is that PKMzeta might go to some synapses, or connections between brain cells, and not others,” Sacktor said. “Over expressed PKMzeta may be selectively captured by molecular tags that mark just those brain connections where it’s needed – likely synapses that were holding the memory from the training.”



About the author:

Ron White is a two-time USA Memory Champion and memory  expert. As a memory  speaker he travels the world to speak before large groups or small company seminars, demonstrating his memory skills and teaching others how to improve their memory, and how important a good memory is in all phases of your life. 


The Jerusalem Post – Scientists manipulate enzyme to counter dementia: