Posted on 12/07/2001 8:29:14 AM PST by RightWhale
New Memories Erase Old By Generating New Neurons
Scientists have found that existing memories may be erased in our brain by a process that involves the generation of new neurons. This clearance might be important to “make room” for the acquisition of new memories.
The results are reported in today's issue of Neuron.
The research team, led by Joe Tsien of the Department of Molecular Biology at Princeton University, generated mice that lack a protein called presenilin-1 throughout much of the brain. Mutations in presenilin-1 are responsible for the majority of cases of early-onset Alzheimer's disease, but the function of the protein in the context of the normal CNS is poorly understood.
These mice were viable and grew normally, but the researchers observed that after spending time in a rich, stimulating environment filled with diversions and mouse toys, the brains of presenilin-1 mutant mice generated fewer new neurons than the brains of normal mice.
Tsien and colleagues initially thought that this reduced neurogenesis might cause learning deficits, but, after months of testing, none could be detected. The researchers did observe, however, that time spent in an enriched environment generally enhanced the retention of recent learning.
To their surprise, they also found that some newly formed memories were harder to erase in the mice lacking presenilin-1 than in the control mice.
This suggested to the authors that generation of new neurons is important for the memory-clearance process.
Memory retention ordinarily seems like a good thing. However, as Tsien points out, “adding new neurons to existing networks may potentially disrupt, rather than improve, the function of these networks”.
These findings raise a possibility that chronic abnormalities in this clearance process may contribute to the devastating memory disorder associated with Alzheimer's disease.
In addition, they raise a potential cautionary note about the therapeutic use of neural stem cell transplantation for neurodegenerative disorders.
Hypothesis: Memory is a process of synthesis with constant reality check via analysis of environment.
Memories are not stored, and cannot be transferred to machines.
Leap to conclusion: This is not the path to immortality.
As opposed to the liberal-leaning medical journal Moron.
That memory is stored in the brain at all is merely a hypothesis. A hypothesis that has produced no useful results.
First, memory, dreams and creativity are easily explained by a single phenomenon, they are all the same.
Second, why in the brain?
Third, equating common sense with logic generates tiny monsters.
That's twice.
No need to be so mysterious, man. Tell us about this phenomenon.
I don't think so. What are you refering to?
Seriously, where do you think memory is stored, the liver?This thread brings to mind (no pun intended) a little-known fact about brain cells. It seems a few years ago some scientists discovered that our stomachs actually contain certain kinds of brain cells. Off hand I don't specifically remember what kinds of brain cells were located there, but it makes one stop and wonder about the old "butterflies-in-the-stomach" and whether or not maybe our brain is trying to tell us something we simply aren't hearing.
Lets start with question 1. How are neurons generated? Cell division? Thanks.
If it is cell division, then the connections and properties of the old cell which has information has to be destroyed. That brings it down to, the things you remeber for a long time, either are contained in neurons that do not reproduce or they are present in more than on neuron, and one of them do not reproduce.
When that happens it is nap time. Some day they may grade students by how many interactive synaptic connections they have in their brain rather than specific ability to regenerate a page of Maclaurin series equivalents. Sleep encourages synaptic linkage growth and thereby improves the memory function. Does that make any sense? Speaking from within my hypothesis.
I forgot what this article was about.
I'm not wearing any pants.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.