Age-related memory loss may be reversible

by Ted Thornhill for The Daily MailLosing your memory as you get older may be reversible, according to the latest research.Scientists believe they have identified specific neurons which, when defective, impair the ability to form medium-term memories. But by stimulating those neurons they believe the memory can be recovered.Ron Davis, chair of the Department of Neuroscience at Scripps Florida, and research association Ayako Tonoki-Yamaguchi, investigated memory and memory traces in the brains of both young and old fruit flies. Like other organisms, from mice to humans, there is a defect that occurs in memory with aging. In the case of the fruit fly, the ability to form intermediate-term memory - which lasts a few hours - is lost due to age-related impairment of the function of certain neurons.Professor Davis said: ‘This study shows that once the appropriate neurons are identified in people, in principle at least, one could potentially develop drugs to hit those neurons and rescue those memories affected by the aging process.‘In addition, the biochemistry underlying memory formation in fruit flies is remarkably similar to that in humans so that everything we learn about memory formation in flies is likely applicable to human memory and the disorders of human memory.’The changes in the brain which cause memory loss are still not understood by scientists but in the current study researchers were able to use functional cellular imaging to monitor the changes in the fly's neuron activity before and after learning.Professor Davis said: ‘We are able to peer down into the fly brain and see changes in the brain. We found changes that appear to reflect how intermediate-term memory is encoded in these neurons.’ During the experiments fruit flies were stimulated to form memories by pairing a smell with a mild electric shock.This technique produced short-term memories that persist for around a half-hour, intermediate-term memory that lasts a few hours, and long-term memory that persists for days.The team found that in aged animals, the signs of encoded memory were absent after a few hours. In that way, the scientists also learned exactly which neurons in the fly are altered by aging to produce intermediate-term memory impairment.This advance should greatly help scientists understand how aging alters neuronal function.Professor Davis and his colleagues then stimulated these neurons to see if the memory could be rescued.To do this, the scientists placed either cold-activated or heat-activated ion channels in the neurons known to become defective with aging and then used cold or heat to stimulate them. In both cases, the intermediate-term memory was successfully rescued.The study was published in the Proceedings of the National Academy of Science.Source: http://bit.ly/HhJtkc