New research throws up a very encouraging possibility – that one day memories apparently forever lost due to Alzheimer’s disease might possibly be restored. It has long been thought that the disease permanently destroys memories, but it appears that might not actually be the case.
Research with mice indicates that the problem might be with our ability to recall memories, rather than the memories being lost. It’s worth remembering, of course, that research such as this is done on mice, not humans, so the results might hold well only for mice. But brain cells are much the same in all mammals, so perhaps the research does have some value (although all animal experimentation is open to criticism).
Ralph Martins, at Edith Cowan University in Australia (who was not part of the research team) said the finding could be ‘revolutionary’. In an interview with New Scientist, he said “It has the potential to lead to novel drug development to help with regaining memories”.
Music has long been known to trigger memories
As he said, there are clues in this research that long-lost memories can be reawakened in people with Alzheimer’s. “Music is the best example” he says, “and it has attracted a lot of attention as a way of retrieving memories of the past in these patients … so it makes sense”.
The research was published in the journal Hippocampus, and was based on mice whose brain cells had been genetically engineered to glow red when they are storing memories, and yellow when memories are being recalled. The research involved shining a laser onto the mouse’s brain using a fibre optic cable so that it could be determined whether the mouse was creating a memory or recalling one.
For the purpose of the experiment, one group of mice were healthy while another had a condition similar to Alzheimer’s. In a memory test, the mice (both groups) were exposed to a lemon scent, which was quickly followed by a mild electric shock.
As you would expect, when the mice again smelled the fragrance they would momentarily freeze, but this happened much less often with the group with the brain disease than the healthy group. This indicated that they didn’t link the smell and the unpleasant shock, or in other words, the memory of it was not being processed.
When the laser was shone on the mice’s brains, it showed that in the healthy mice the red and yellow cells were linked in the hippocampus, the region of the brain most closely linked to memory creation.
Jumbled memories create a state of total confusion
However, in the other group (those with the brain malfunction), different cells glowed red, indicating the mice were recalling an unconnected memory. This is the type of thing that is found in Alzheimer’s patients; they can be completely focused one moment, and then it appears that their brain is tackling some unrelated memories, resulting in utter confusion.
The problem, therefore, might be that memories in Alzheimer’s patients are not being processed properly from the beginning, or in other words, memories are not being stored correctly. Little wonder then that patients encounter problems when they try to recall those memories. And not surprising either that they can often still recall things from years gone by, when the memories were still being processed correctly.
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