Neuroscientists at the University of Nevada have shown how type 2 diabetes may be linked to Alzheimer’s disease.
Published online in Communications Biology, researchers determined that chronic hyperglycemia disrupts working memory performance, impacting working memory networks.
“It is thought that chronic hyperglycemia leads to neuroinflammation and tau hyperphosphorylation in the hippocampus leading to cognitive decline, but effects on hippocampal network activity are unknown,” according to the findings.
“A sustained hyperglycemic state was induced in otherwise healthy animals and subjects were then tested on a spatial delayed alternation task while recording from the hippocampus and anterior cingulate cortex (ACC). Hyperglycemic animals performed worse on long delay trials and had multiple electrophysiological differences throughout the task.”
When investigating the link between type 2 diabetes and Alzheimer’s disease, researchers uncovered that the hippocampus and the anterior cingulate cortex, both crucial in memory formation and retrieval, had been hypersynchronized.
“We found increased delta power and decreased theta power in the hippocampus, which led to altered theta/delta ratios at the end of the delay period,” the authors explained in their findings.
“Cross frequency coupling was significantly higher in multiple bands and delay period hippocampus-ACC theta coherence was elevated, revealing hypersynchrony.”
“Future work is needed to disentangle how insulin levels affect network dysfunction and working memory impairments, where insulin levels are controlled after streptozotocin treatment,” the authors also mentioned.
The study was funded by a grant from the National Institute on Aging.