Hyperglycemia from chronic stress may cause spatial memory impairment!

Hyperglycemia from chronic stress may cause spatial memory impairment!

Stress increases levels of circulating glucose and has been linked to metabolic disorders such as diabetes and mental disorders such as depression. However, whether stress-induced changes in glucose metabolism cause cognitive impairments, which are common in metabolic disorders, remains unclear.

Researchers found that chronic stress-induced increases in glucose levels impair spatial memory in mice. The authors induced chronic stress by exposing mice to aggressive encounters for 10 days. Compared with mice not exposed to social defeat, mice that experienced chronic stress had elevated glucose levels and impaired glucose metabolism peripherally as well as in the brain.

Moreover, socially defeated mice did not show the normal preference for the novel arm of a Y-maze, indicating spatial memory impairment. Treatment with the glucose-lowering diabetes drug empagliflozin improved spatial memory in 36% of susceptible mice that had high blood glucose levels 2 days after social defeat. Conversely, reducing glucose levels by empagliflozin in mice that did not display stress-induced hyperglycemia (resilient mice) impaired their default-intact spatial memory performance.

Together, the results suggest that blood glucose levels following stress could serve as a biomarker to determine individual stress vulnerability and predict the effectiveness of empagliflozin treatment.

According to the authors, the findings may explain why diabetes and depression often occur together, potentially opening avenues for early intervention and tailored treatment.