Memories banished by Alzheimer’s can in theory be rescued by stimulating nerve cells to grow new connections, a study has shown.
The research, conducted in mice, raises the possibility of future treatments that reverse memory loss in early stages of the disease. Scientists used a technique called optogenetics, which uses light to activate cells tagged with a special photo-sensitive protein.
It was tested on mice with Alzheimer’s-like symptoms that quickly forgot the experience of receiving a mild electric shock to their feet. After tagged cells in their brains were stimulated with light, their memory returned and they displayed a fear response when placed in the chamber where the shock had been applied an hour earlier.
The optogenetic treatment helped the neurons re-grow small buds called dendritic spines, which form synaptic connections with other cells. Although the same technique cannot be used in humans, the research points the way to future memory-retrieving therapies, say the researchers.
- (Nature) Memory retrieval by activating engram cells in mouse models of early Alzheimer’s disease
- (The Guardian) Nerve cell stimulation ‘may recall memories’ in Alzheimer’s patients
- (NIH) Optogenetic stimulation of a hippocampal engram activates fear memory recall
- (MIT) Researchers find “lost” memories
- (Neuroscience News) Memories Lost to Alzheimer’s Can Be Found