Neuroscience professor Laura Colgin and her lab have potentially found a way to diagnose Alzheimer’s disease earlier.
More than five million Americans are affected by Alzheimer’s, but little is known about it, according to the Alzheimer’s Association. Colgin’s lab measured brain activity in mice exhibiting Alzheimer’s and recorded changes in place cells, which are brain cells that help mice recognize their surroundings. Researchers measured specific patterns of place cell activation, called slow gamma rhythms, which can predict upcoming locations of the mouse.
According to the study, mice with Alzheimer’s symptoms were unable to access slow gamma rhythms, which authors hypothesized are important for memory. Alex Mably, postdoctoral researcher, said that studying gamma rhythms could allow doctors to detect Alzheimer’s at earlier stages.
“If Alzheimer’s could be diagnosed earlier the hope is that we could halt these biochemical changes before they happen, or target them early enough for them to be reversible,” Mably said. “Brain rhythms are a good candidate for early diagnosis as they can be recorded using non-invasive techniques.”
Colgin said the fact that the cells are still present potentially gives hope to people in early stages of Alzheimer’s, who may benefit from new therapies.
“If patients can’t store memories, then they can’t recall them, but since we did actually see some (unstable representations) of space (in place cells), then it potentially means that there is a problem with retrieving the stored memory,” Colgin said. “Therapeutic intervention could … help patients access these memories.”
According to a study by the National Library of Medicine, Alzheimer’s likely results from plaques, or aggregated proteins, that develop in the hippocampus, a structure in the brain important for encoding memories. Colgin said place cells in the hippocampus encode memory of what happened in a specific place.
One of the first symptoms of Alzheimer’s is getting lost in familiar places, which Colgin said is an indication of disturbed place cells. The results of this study support the hypothesis that mice with Alzheimer’s can correctly store, but not retrieve, memories, Colgin said. Researchers collected brain rhythm data with electrodes called electroencephalograms, which record brain patterns.
“You can see and hear the neurons firing in real time as the mouse moves around its environment, which is pretty cool,” Mably said.
Colgin said the research could have applications in other facets of Alzheimer’s disease and diseases such as fragile X syndrome, a behavioral disorder that is also difficult to diagnose.
“Our research is really exciting … if we learn mechanisms that underlie the generations of rhythms then potentially we can find a way to restore healthy brains,” she said.