Researchers at the University of California, San Diego have given rats memories, erased them, then restored the memories again. In a study published June 1, 2014, in an advanced online issue of the journal, Nature, researchers explain how synaptic connections in the brain can manipulate memory in rats.
Roberto Malinow, MD, PhD, professor of neurosciences, and senior author of the study, states, “We can form a memory, erase that memory and we can reactivate it, at will, by applying a stimulus that selectively strengthens or weakens synaptic connections”. Rats’ brains had been genetically modified to make them sensitive to light. The researchers optically stimulated nerves while applying shock treatments to the rats’ feet. The rats soon associated the optic stimulation with pain. Biological chemicals were produced by the rats that showed synaptic strengthening. This means that the rats can remember more clearly.
The researchers then found that by stimulating those same nerves with low frequency optical pulses, the rats no longer responded negatively to the original optic stimuli. The research team concluded that the rats had, in deed, forgotten the pain. The team then reversed the stimuli and gave the rats high frequency stimuli and the fear reaction returned.
The reason for the study…Alzheimer’s disease! Beta amyloid peptide gathers in the brains of Alzheimer’s patients and weakens the synapses just as the optic stimuli did in the rats. By finding a way to restore the memory of the rats, Dr. Malinow and his team are one step closer to finding a way to reverse the memory loss in Alzheimer’s patients.