New research could lead to treatments for memory-related disorders.Dentate Gyrus NMDA Receptors Mediate Rapid Pattern Separation in the Hippocampal Network.
Dentate gyrus pattern.
(Credit: Matt Jones)
In today's fast-moving world of look-alike hotel rooms and comparable corridors, it can take a bit of thinking to answer this simple question. University of Bristol neuroscientists working with colleagues at the Massachusetts Institute of Technology (MIT) report in the June 7 early online edition of Science that they have identified a neuronal mechanism that our brains may use to rapidly distinguish similar, yet distinct places.
The work could lead to treatments for memory-related disorders, as well as for the confusion and disorientation that plague elderly individuals who have trouble distinguishing between separate but similar places and experiences.
Forming memories of places and contexts in which episodes occur engages a part of the brain called the hippocampus. The laboratory of Nobel Laureate, Susumu Tonegawa, Picower Professor of Biology and Neuroscience at MIT, has been exploring how each of the three hippocampal subregions-the dentate gyrus, CA1 and CA3-contribute uniquely to different aspects of learning and memory.
In the current study, co-authors Matthew Jones, Research Councils UK (RCUK) Academic Fellow in the Department of Physiology at the University of Bristol and Dr Thomas McHugh, a Picower Institute research scientist, have revealed that the learning in the dentate gyrus is crucial in rapidly recognizing and amplifying the small differences that make each place unique.
"We constantly make split-second decisions about how best to behave at a given place and time. To achieve this, our nervous system must employ highly efficient ways of rapidly recognising and learning important changes in our environment" said Dr Jones.
"This paper demonstrates that a particular protein signalling molecule (the NMDA receptor) in a particular network of brain neurons (the dentate granule cells of the hippocampus) is essential for these rapid discrimination processes, hopefully paving the way for therapies targeting learning and behavioural disorders."
Researchers believe that a set of neurons called 'place cells' fire to provide a sort of blueprint for any new space we encounter. The next time we see the space, those same neurons fire. Thus we know when we've been somewhere before and don't have to relearn our way around familiar turf. But similar spaces may activate overlapping neuronal blueprints, leaving room for confusion if the neurons are not fine-tuned.
In this study, the researchers used a line of genetically altered mice to pinpoint how the dentate gyrus contributes to the kind of pattern separation involved in identifying new and old spaces. Whilst the mice behaved normally in most situations, they became confused when required to discriminate between different spaces. This may model the difficulties in forming distinct memories for similar but distinct places and experiences that afflicts some elderly individuals.
Have I Been Hear Before?
Neuronal Mechanism Could Help Explain Déjà-vu
Bristol University Press release issued 7 June 2007
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8 comments:
I get that deja vu feeling all the time ... but I just thought it was my past lives coming back to haunt me!
I also sometimes get that deja vu thing. It sure would be great if scientist can get a handle on memory loss though.
tea
xo
Did I read this before?
Did I comment before?
I don't think so, but how can I be sure?
Interesting topic
... it would be amazing if they could find a way to cure [lessen the effects off] Alzheimer's'
Hi Aggie, that was the old theory
that somehow we recognise places we've been before.
Easier to do in Old Europe, where we have Old buildings dating back 500 to a thousand years or more.
After all walking around Trinity College, one can feel like a Time Traveller, and if people around dressed in period costume - one wouldn't be able to tell reality from the stage.
But this research seems to suggest that the mind might play some tricks on US, by looking for the familiar even in unfamiliar places.
ie: walking thru a forest, would create that feeling if the forest had the same kind of trees.
The other side of the coin, is the homogenization of Cities, where City Centres in the late 20th Century and early 21st begin to look the same. After all if you have a Starbucks and McDonalds, you start looking for individual landmarks (or people) to help you identify which City you are in -
Tea, a song or a smell can take us back down memory lane.
As for memory loss, we want to fill our life with experiences, the more memories we add the harder it is to recall all.
In the old days they used to say, fill your life with fond memories to dwell on in your old age ...
but it is strange that so many old people cannot access or hold onto current memories (of places & faces) - but they seem to get lost in some earlier (childhood) or past moment of their life ...
Perhaps it is the need for the older Mind to be comfortable, in an ever changing world, one changing at an incredibly fast place - and clearly leaving some behind.
lol Annelisa,
how can we ever be sure of anything
We look for comfort zones and reassuring places in our Mind, and or our external environment.
Some when young love change, others when older cannot keep up with the pace of change
Hi Random,
New Alzheimer's Drug Begins Clinical Trials
Warning: the biochemical industry may once again be promising miracles to the vulnerable.
Can drugs make you happy or sad, sure alcohol can enhance your mood, but it can go equally either way. As to preventing memory loss, though it must clearly be a 'physical' process, I'm of the persuasion that it is the individual mind is being selective of which information it processes, seeking a cocoon or comfort zone, without realizing of course that it is shutting out loved ones, and the confusion it creates when the mind ceases to recognise known faces or places.
But hey my eyes play tricks on me everyday - so maybe it's their eyesight they should check first.
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