Shedding light on the dynamics of memory: Researchers find mechanism that maintains memories

Apr 13, 2010

(PhysOrg.com) -- Why do we remember? What allows our brains to retain bits of information (while forgetting others) for years and years? Why can we remember things that happened decades ago, but forget whether we left the lights on when we left home this morning?

Researchers at McGill University have made strides toward unraveling one of the most fundamental mysteries in neuroscience - how the maintains memories over time.

The McGill team, led by Prof. Karim Nader, discovered that the activity of one molecule in the brain, the PKM ζ, plays a key role in allowing the brain to retain memories. The molecule prevents the removal of synaptic receptors in the brain that would, if they were destroyed, lead to loss. The results will be published in the journal Nature Neuroscience on April 11.

"This finding has very important implications for the understanding of the dynamics of memory because it shows that memory persists due to an active counter-balancing process between the mechanisms that keep the memory stored and the mechanisms that will lead to the erasure of the memory." explained Nader, William Dawson Scholar and EWR Steacie Fellow in McGill's Department of Psychology.

This latest finding builds on the work of Todd Sacktor, of SUNY Downstate Medical Centre, on memory maintenance, and of Yu Tian Wang, of the University of British Columbia, on receptor trafficking. In 2006, Sacktor unraveled the role of the continuous activity of the molecule protein kinase PKMζ, and showed it to be necessary and sufficient for the persistence of memories over time. He showed that established, long-term memories can be erased by deactivating this enzyme. Nader and post-doctoral student Paola Virginia Migues took these findings a step further by discovering that the enzymatic activity of PKMζ is required to prevent the removal of a pool of receptors at the synaptic connections. These receptors are responsible for the strength of the connections between neurons and without these receptors memory cannot be expressed.

The new findings enhance our understanding of memory storage and erasure mechanisms and how the perpetuation of long-term memories relies on a dynamic balance between these two processes.

"These findings are exciting because... until 2006, nothing was known about how memories are maintained over time. With the finds from Sacktor's group they identified the first candidate molecule to mediate memory maintenance. Now we have an idea of how this all works." Nader said.

Explore further: Neurons can be reprogrammed to switch the emotional association of a memory

Related Stories

Brain's memory storing is studied

Mar 01, 2006

University of California-Irvine scientists have identified the neural activity that occurs when the brain "sets the stage" for retaining a memory.

Scientists capture the first image of memories being made

Jun 18, 2009

The ability to learn and to establish new memories is essential to our daily existence and identity; enabling us to navigate through the world. A new study by researchers at the Montreal Neurological Institute ...

To make memories, new neurons must erase older ones

Nov 12, 2009

Short-term memory may depend in a surprising way on the ability of newly formed neurons to erase older connections. That's the conclusion of a report in the November 13th issue of the journal Cell that provid ...

Recommended for you

Emotional adjustment following traumatic brain injury

12 hours ago

Life after a traumatic brain injury resulting from a car accident, a bad fall or a neurodegenerative disease changes a person forever. But the injury doesn't solely affect the survivor – the lives of their spouse or partner ...

New ALS associated gene identified using innovative strategy

Oct 22, 2014

Using an innovative exome sequencing strategy, a team of international scientists led by John Landers, PhD, at the University of Massachusetts Medical School has shown that TUBA4A, the gene encoding the Tubulin Alpha 4A protein, ...

User comments : 6

Adjust slider to filter visible comments by rank

Display comments: newest first

Wasabi
5 / 5 (3) Apr 13, 2010
Phenomenal discovery! Scary to think though how simple a matter it is to erase long term storage though. Hello Zombies if that ever happened on any kind of mass scale. Levity aside though, this is exciting news.
trekgeek1
4 / 5 (1) Apr 13, 2010
This could be used for evil, but most things can be. This could also be used for helping people who witnessed a traumatizing event that they want to forget. This could be great for therapy and soldiers returning home who don't want the memories to follow.
PinkElephant
not rated yet Apr 13, 2010
@trekgeek1,

I don't think this would make a very good therapy approach. It would indiscriminately destroy all memories, regardless of whether they formed 25 or 3 or 0.1 years ago.
bottomlesssoul
not rated yet Apr 13, 2010
This could be used for evil, but most things can be. This could also be used for helping people who witnessed a traumatizing event that they want to forget. This could be great for therapy for victims of soldiers "fog of war" who don't want the memories to follow.

Sry, just being ironic.
ricarguy
not rated yet Apr 14, 2010
This is artificially induced amnesia. So how is knowledge different than memories? "Zap" and the poor patient is now effectively autistic until he relearns everything...and he used to be a brain surgeon too. You'd think he'd have known better.
ricarguy
not rated yet Apr 14, 2010
Seriously, we are off on a tangent here. This appears to be a step in basic understanding of how things work. Selectively deleting memories as is suggested above would take a poke with a needle and what we have here might be like a sledge hammer.
Still if we can learn to reshape the mind, imagine the capability of reprogramming a career criminal, a militant terrorist or just a political opponent? Science fiction at its best. I just hope it remains fiction.