Fosters lab group used aged and young rats to examine the relationships between LTD, aging and memory. The animals were trained to find a hidden platform to climb out of a pool of water - something they learned quickly with repetition.
When the researchers examined the animals neurons and used a slow, weak electrical signal to make the synapses less sensitive - an effort to squelch or depress the cellular communication - he found that the samples from younger animals and older animals that had the highest memory scores throughout their lives were more resistant to the interference. However, aged animals with impaired memories displayed what was termed as robust long-term depression.
Going back to the phone call example, not only did the rest of the room get quieter, the callers did, too. The assumption is if a memory is encoded by making synapses stronger, then memory can be disrupted by something that weakens those connections.
When we see someone we know or perhaps even ourselves becoming more forgetful, we now know that this is not an inevitable process, Foster said. Further, as we begin to understand the mechanisms of memory, it becomes possible to predict promising targets for therapeutic strategies aimed at postponing or alleviating age-related memory impairment.
Foster said it will be important to understand whether a change in cellular signaling is necessary to enable new memories to be formed by discarding old ones.
The basic gist is that information storage requires a balance between mechanisms that make synapses stronger and weaker, said Mark F. Bear, Ph.D., director of the Picower Institute for Learning and Memory at the Massachusetts Institute of Technology, who was not involved with the research. In aging and disease, if that balance is dis
Contact: April Birdwell
University of Florida